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Additions to the NASA Aeronautics and Space Database as of 12/30/2008
20080047339 NASA Glenn Research Center, Cleveland, OH, United States
Application of an Elongated Kelvin Model to Space Shuttle Foams
Sullivan, Roy M.; Ghosn, Louis J.; Lerch, Bradley A.; April 07, 2008; In English; 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 7 - 10 Apr. 2008, Illinois, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047339
Spray-on foam insulation is applied to the exterior of the Space Shuttle s External Tank to limit propellant boil-off and to prevent ice formation. The Space Shuttle foams are rigid closed-cell polyurethane foams. The two foams used most extensively on the Space Shuttle External Tank are BX-265 and NCFI24-124. Since the catastrophic loss of the Space Shuttle Columbia, numerous studies have been conducted to mitigate the likelihood and the severity of foam shedding during the Shuttle s ascent to space. Due to the foaming and rising process, the foam microstructures are elongated in the rise direction. As a result, these two foams exhibit a non-isotropic mechanical behavior. In this paper, a detailed microstructural characterization of the two foams is presented. The key features of the foam cells are summarized and the average cell dimensions in the two foams are compared. Experimental studies to measure the room temperature mechanical response of the two foams in the two principal material directions (parallel to the rise and perpendicular to the rise) are also reported. The measured elastic modulus, proportional limit stress, ultimate tensile stress and the Poisson s ratios for the two foams are compared. The generalized elongated Kelvin foam model previously developed by the authors is reviewed and the equations which result from this model are presented. The resulting equations show that the ratio of the elastic modulus in the rise direction to that in the perpendicular-to-rise direction as well as the ratio of the strengths in the two material directions is only a function of the microstructural dimensions. Using the measured microstructural dimensions and the measured stiffness ratio, the foam tensile strength ratio and Poisson s ratios are predicted for both foams. The predicted tensile strength ratio is in close agreement with the measured strength ratios for both BX-265 and NCFI24-124. The comparison between the predicted Poisson s ratios and the measured values is not as favorable.
Author
FOAMS; INSULATION; EXTERNAL TANKS; MICROSTRUCTURE; TENSILE STRENGTH; MECHANICAL PROPERTIES; POLYURETHANE FOAM; TENSILE STRESS; SPRAYERS
20080047340 NASA Glenn Research Center, Cleveland, OH, United States
TBCC Fan Stage Operability and Performance
Suder, Kenneth L.; October 31, 2007; In English; NASA Fundamental Aeronautics Program 2007 Annual Meeting, 31 Oct. - 01 Nov. 2007, Louisiana, FROM; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047340
NASA s Fundamental Aeronautics Program is investigating turbine-based propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. Studies performed under NASA s NGLT and the NASP High Speed Propulsion Assessment (HiSPA) program indicated a variable cycle turbofan/ramjet was the best configuration to satisfy access-to-space mission requirements because this configuration maximizes the engine thrust-to-weight ratio while minimizing frontal area. To this end, NASA and GE teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10X), fan speed (7X), inlet mass flow (3.5X), inlet pressure (8X), and inlet temperature (3X). The primary goal of the fan stage was to provide a high pressure ratio level with good efficiency at takeoff through the mid range of engine operation, while avoiding stall and losses at the higher flight Mach numbers, without the use of variable inlet guide vanes. Overall fan performance and operability therefore requires major consideration, as competing goals at different operating points and aeromechanical issues become major drivers in the design. To mitigate risk of meeting the unique design requirements for the fan stage, NASA and GE teamed to design and build a 57% engine scaled fan stage to be tested in NASA s transonic compressor facility. The objectives of this test are to assess the aerodynamic and aero mechanic performance and operability characteristics of the fan stage over the entire range of engine operation including: 1) sea level static take-off, 2) transition over large swings in fan bypass ratio, 3) transition from turbofan to ramjet, and 4) fan windmilling operation at high Mach flight conditions. In addition, the fan stage design was validated by performing pre-test CFD analysis using both GE proprietary and NASA s APNASA codes. Herein we will discuss 1) the fan stage design, 2) the experiment including the unique facility and instrumentation, and 3) the comparison of pre-test CFD analysis to initial aerodynamic test results for the baseline fan stage configuration. Measurements and pre-test analysis will be compared at 37%, 50%, 80%, 90%, and 100% of design speed to assess the ability of state-of-the-art design and analysis tools to meet the fan stage performance and operability requirements for turbine based propulsion for access to space.
Author
PROPULSION SYSTEM CONFIGURATIONS; COMPUTATIONAL FLUID DYNAMICS; DESIGN ANALYSIS; HIGH SPEED; PROPULSION SYSTEM PERFORMANCE; INLET PRESSURE
20080047343 NASA Glenn Research Center, Cleveland, OH, United States
Seal Technology for Hypersonic Vehicle and Propulsion: An Overview
Steinetz, Bruce M.; February 26, 2008; In English; Short Course on Hypersonics Structures and Materials, 26 - 28 Feb. 2008, Virginia, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A06, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047343
Hypersonic vehicles and propulsion systems pose an extraordinary challenge for structures and materials. Airframes and engines require lightweight, high-temperature materials and structural configurations that can withstand the extreme environment of hypersonic flight. Some of the challenges posed include very high temperatures, heating of the whole vehicle, steady-state and transient localized heating from shock waves, high aerodynamic loads, high fluctuating pressure loads, potential for severe flutter, vibration, and acoustic loads and erosion. Correspondingly high temperature seals are required to meet these aggressive requirements. This presentation reviews relevant seal technology for both heritage (e.g. Space Shuttle, X-15, and X-38) vehicles and presents several seal case studies aimed at providing lessons learned for future hypersonic vehicle seal development. This presentation also reviews seal technology developed for the National Aerospace Plane propulsion systems and presents several seal case studies aimed at providing lessons learned for future hypersonic propulsion seal development.
Author
SEALS (STOPPERS); HYPERSONIC VEHICLES; REFRACTORY MATERIALS; AERODYNAMIC LOADS; AIRFRAMES; HIGH TEMPERATURE; PROPULSION SYSTEM CONFIGURATIONS; PRESSURE DISTRIBUTION
20080047346 NASA Langley Research Center, Hampton, VA, United States
A Performance Assessment of a Tactical Airborne Separation Assistance System using Realistic, Complex Traffic Flows
Smith, Jeremy C.; Neitzke, Kurt W.; Bussink, Frank J. L.; November 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 411931.02.71.07.01
Report No.(s): NASA/TM-2008-215546; L-19519; Copyright; Avail.: CASI: A03, Hardcopy
This paper presents the results from a study that investigates the performance of aspects of an Airborne Separation Assistance System (ASAS) under varying demand levels using realistic traffic patterns. This study only addresses the tactical aspects of an ASAS using aircraft state data (latitude, longitude, altitude, heading and speed) to detect and resolve projected conflicts. The main focus of this paper is to determine the extent to which sole reliance on the proposed tactical ASAS can maintain aircraft separation at demand levels up to three times current traffic. The effect of mixing ASAS equipped aircraft with non-equipped aircraft that do not have the capability to self-separate is also investigated.
Author
SEPARATORS; LONGITUDE; LATITUDE; ALTITUDE; AIRBORNE EQUIPMENT
20080047347 NASA Glenn Research Center, Cleveland, OH, United States
The Effects of Heat Treatment and Microstructure Variations on Disk Superalloy Properties at High Temperature
Gabb, Timothy P.; Gayda, John; Telesman, Jack; Garg, Anita; September 14, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 698259.02.07.03.04.01
Copyright; Avail.: CASI: A02, Hardcopy
The effects of heat treatment and resulting microstructure variations on high temperature mechanical properties were assessed for a powder metallurgy disk superalloy LSHR. Blanks were consistently supersolvus solution heat treated and quenched at two cooling rates, than aged at varying temperatures and times. Tensile, creep, and dwell fatigue crack growth tests were then performed at 704 C. Gamma' precipitate microstructures were quantified. Relationships between heat treatment-microstructure, heat treatment-mechanical properties, and microstructure-mechanical properties were assessed.
Author
HEAT RESISTANT ALLOYS; HIGH TEMPERATURE; MICROSTRUCTURE; TEMPERATURE EFFECTS; CRACK PROPAGATION; FATIGUE (MATERIALS); POWDER METALLURGY
20080047348 NASA Glenn Research Center, Cleveland, OH, United States
Monitoring Delamination of Thermal Barrier Coatings by Near-Infrared and Upconversion Luminescence Imaging
Eldridge, J. I.; Martin, R. E.; Singh, Jogender; Wolfe, Doug E.; April 28, 2008; In English; ICMCTF, 30 Apr. 2008, San Diego, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.03
Copyright; Avail.: CASI: A03, Hardcopy
Previous work has demonstrated that TBC delamination can be monitored by incorporating a thin luminescent sublayer that produces greatly increased luminescence intensity from delaminated regions of the TBC. Initial efforts utilized visible-wavelength luminescence from either europium or erbium doped sublayers. This approach exhibited good sensitivity to delamination of electron-beam physical-vapor-deposited (EB-PVD) TBCs, but limited sensitivity to delamination of the more highly scattering plasma-sprayed TBCs due to stronger optical scattering and to interference by luminescence from rare-earth impurities. These difficulties have now been overcome by new strategies employing near-infrared (NIR) and upconversion luminescence imaging. NIR luminescence at 1550 nm was produced in an erbium plus ytterbium co-doped yttria-stabilized zirconia (YSZ) luminescent sublayer using 980-nm excitation. Compared to visible-wavelength luminescence, these NIR emission and excitation wavelengths are much more weakly scattered by the TBC and therefore show much improved depth-probing capabilities. In addition, two-photon upconversion luminescence excitation at 980 nm wavelength produces luminescence emission at 562 nm with near-zero fluorescence background and exceptional contrast for delamination indication. The ability to detect TBC delamination produced by Rockwell indentation and by furnace cycling is demonstrated for both EB-PVD and plasma-sprayed TBCs. The relative strengths of the NIR and upconversion luminescence methods for monitoring TBC delamination are discussed.
Author
THERMAL CONTROL COATINGS; CYCLES; DELAMINATING; LUMINESCENCE; IMAGING TECHNIQUES; OPTICAL PROPERTIES
20080047349 NASA Glenn Research Center, Cleveland, OH, United States
Durability Assessment of TiAl Alloys
Draper, Susan L.; Lerch, Bradley A.; March 09, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489 02.07.03.02.04.01
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047349
The durability of TiAl is a prime concern for the implementation of TiAl into aerospace engines. Two durability issues, the effect of high temperature exposure on mechanical properties and impact resistance, have been investigated and the results are summarized in this paper. Exposure to elevated temperatures has been shown to be detrimental to the room temperature ductility of gamma alloys with the most likely mechanisms being the ingress of interstitials from the surface. Fluorine ion implantation has been shown to improve the oxidation resistance of gamma alloys, and ideally it could also improve the environmental embrittlement of high Nb content TiAl alloys. The effect of F ion implantation on the surface oxidation and embrittlement of a third generation, high Nb content TiAl alloy (Ti-45Al-5Nb-B-C) were investigated. Additionally, the ballistic impact resistance of a variety of gamma alloys, including Ti-48Al-2Cr- 2Nb, Ti-47Al-2Cr-2Nb, ABB-2, ABB-23, NCG359E, 95A and Ti-45Al-5Nb-B-C was accessed. Differences in the ballistic impact properties of the various alloys will be discussed, particularly with respect to their manufacturing process, microstructure, and tensile properties.
Author
TENSILE PROPERTIES; TITANIUM ALUMINIDES; IMPACT RESISTANCE; MECHANICAL PROPERTIES; IMPACT STRENGTH; EMBRITTLEMENT; TEMPERATURE EFFECTS
20080047350 NASA Glenn Research Center, Cleveland, OH, United States
The In-Space Propulsion Technology Project Low-Thrust Trajectory Tool Suite
Dankanich, John W.; [2008]; In English
Contract(s)/Grant(s): NNC07QA54DWBS 346620.01.03.01
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047350
The ISPT project released its low-thrust trajectory tool suite in March of 2006. The LTTT suite tools range in capabilities, but represent the state-of-the art in NASA low-thrust trajectory optimization tools. The tools have all received considerable updates following the initial release, and they are available through their respective development centers or the ISPT project website.
Author
LOW THRUST; TRAJECTORIES; TRAJECTORY ANALYSIS; TRAJECTORY OPTIMIZATION; PROPULSION
20080047351 NASA Glenn Research Center, Cleveland, OH, United States
Advanced Stirling Convertor (ASC) - From Technology Development to Future Flight Product
Wong, Wayne A.; Wood, J. Gary; Wilson, Kyle; February 13, 2008; In English; Space Technology and Applications International Forum, 13 Feb. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 138494.04.01.01
Copyright; Avail.: CASI: A03, Hardcopy
The Advanced Stirling Convertor (ASC) is being developed by Sunpower, Inc. under contract to NASA s Glenn Research Center (GRC) with critical technology support tasks lead by GRC. The ASC development, funded by NASA s Science Mission Directorate, started in 2003 as one of 10 competitively awarded contracts that were to address future Radioisotope Power System (RPS) advanced power conversion needs. The ASC technology has since evolved through progressive convertor builds and successful testing to demonstrate high conversion efficiency (38 %), low mass (1.3 kg), hermetic sealing, launch vibration simulation, EMI characterization, and is undergoing extended operation. The GRC and Sunpower team recently delivered three ASC-E machines to the Department of Energy (DOE) and Lockheed Martin Space Systems Company, two units for integration onto the Advanced Stirling Radioisotope Generator Engineering Unit (ASRG EU) plus one spare. The design has recently been initiated for the ASC-E2, an evolution from the ASC-E that substitutes higher temperature materials enabling improved performance and higher reliability margins. This paper summarizes the history and status of the ASC project and discusses plans for this technology which enables RPS specific power of 8 W/kg for future NASA missions.
Author
STIRLING CYCLE; ENERGY CONVERSION EFFICIENCY; SYSTEMS INTEGRATION; AEROSPACE SYSTEMS
20080047352 Case Western Reserve Univ., Cleveland, OH, United States
Formation of gamma(sup prime)-Ni3Al via the Peritectoid Reaction: gamma + beta (+ Al2O3)=gamma(sup prime)(+ Al2O3)
Copeland, Evan; September 14, 2008; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNC07BA13BWBS 561581.02.08.03.15.03
Copyright; Avail.: CASI: A02, Hardcopy
The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8-32 at.%Al and temperature range T=1400-1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma(sup prime)-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3)=gamma + Beta(+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%al (at an unknown oxygen content). The {gamma + Beta (+Al2O3} phase field is stable over the temperature range 1633-1640 K, and gamma(sup prime)-Ni3Al forms via the peritectoid, gamma + Beta (+ Al2O3)=gamma(sup prime) (+ Al2O3), at 1633 +/- 1 K. This behavior is consistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(sup prime)-Ni2Al phase field.
Author
NICKEL ALUMINIDES; CHEMICAL REACTIONS; THERMODYNAMIC PROPERTIES; HEAT RESISTANT ALLOYS
20080047353 NASA Glenn Research Center, Cleveland, OH, United States
Design and Fabrication of a 5-kWe Free-Piston Stirling Power Conversion System
Chapman, Peter A.; Walter, Thomas J.; Brandhorst, Henry W., Jr.; July 28, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06CB81CAUSRI 07-SRI-208447-FMIWBS 463169.04.03.04.01.03
Copyright; Avail.: CASI: A02, Hardcopy
Progress in the design and fabrication of a 5-kWe free-piston Stirling power conversion system is described. A scaled-down version of the successful 12.5-kWe Component Test Power Converter (CTPC) developed under NAS3-25463, this single cylinder prototype incorporates cost effective and readily available materials (steel versus beryllium) and components (a commercial linear alternator). The design consists of a displacer suspended on internally pumped gas bearings and a power piston/alternator supported on flexures. Non-contacting clearance seals are used between internal volumes. Heat to and from the prototype is supplied via pumped liquid loops passing through shell and tube heat exchangers. The control system incorporates several novel ideas such as a pulse start capability and a piston stroke set point control strategy that provides the ability to throttle the engine to match the required output power. It also ensures stable response to various disturbances such as electrical load variations while providing useful data regarding the position of both power piston and displacer. All design and analysis activities are complete and fabrication is underway. Prototype test is planned for summer 2008 at Foster-Miller to characterize the dynamics and steady-state operation of the prototype and determine maximum power output and system efficiency. Further tests will then be performed at Auburn University to determine start-up and shutdown characteristics and assess transient response to temperature and load variations.
Author
STIRLING CYCLE; POWER CONVERTERS; DESIGN ANALYSIS; LOADS (FORCES); GAS BEARINGS; POWER EFFICIENCY
20080047354 NASA Glenn Research Center, Cleveland, OH, United States
Comparison of the Isothermal Oxidation Behavior of As-Cast Cu-17%Cr and Cu-17%Cr-5%Al Part 1 Oxidation Kinetics
Raj. Sai V.; [2008]; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.02
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047354
The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1173 K under atmospheric pressure. These observations reveal that Cu- 17%Cr-5%Al oxidizes at significantly slower rates than Cu-17%Cr. The rate constants for the alloys were determined from generalized analyses of the data without an a priori assumption of the nature of the oxidation kinetics. Detailed analyses of the isothermal thermogravimetric weight change data revealed that Cu-17%Cr exhibited parabolic oxidation kinetics with an activation energy of 165.9 +/- 9.5 kJ/mol. In contrast, the oxidation kinetics for the Cu-17%Cr- 5%Al alloy exhibited a parabolic oxidation kinetics during the initial stages followed by a quartic relationship in the later stages of oxidation. Alternatively, the oxidation behavior of Cu-17%CR- 5%Al could be better represented by a logarithmic relationship. The parabolic rate constants and activation energy data for the two alloys are compared with literature data to gain insights on the nature of the oxidation mechanisms dominant in these alloys.
Author
REACTION KINETICS; ATMOSPHERIC PRESSURE; ACTIVATION ENERGY; THERMOGRAVIMETRY; COPPER ALLOYS
20080047356 NASA Glenn Research Center, Cleveland, OH, United States
Comparison of the Isothermal Oxidation Behavior of As-Cast Cu-17%Cr and Cu-17%Cr-5%Al Part II: Scale Microstructures
Raj, Sai V.; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.02
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047356
The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1173 K under atmospheric pressure. Details of the oxidation kinetics of these alloys were discussed in Part I. This paper analyzes the microstructures of the scale and its composition in an attempt to elucidate the oxidation mechanisms in these alloys. The scales formed on Cu-17%Cr specimens oxidized between 773 and 973 K consisted of external CuO and subsurface Cu2O layers. The total thickness of these scales varied from about 10 m at 773 K to about 450 m at 973 K. In contrast, thin scales formed on Cu-17%Cr-5%Al alloys oxidized between 773 and 1173 K. The exact nature of these scales could not be determined by x-ray diffraction but energy dispersive spectroscopy analyses were used to construct a scale composition map. Phenomenological oxidation mechanisms are proposed for the two alloys.
Author
COPPER ALLOYS; REACTION KINETICS; X RAY DIFFRACTION; PHENOMENOLOGY; MICROSTRUCTURE; CASTINGS; ATMOSPHERIC PRESSURE
20080047357 NASA Glenn Research Center, Cleveland, OH, United States
Progress in High Power Free-Piston Stirling Convertor Development
Brandhorst, Henry W., Jr.; Kirby, Raymond L.; Chapman, Peter A.; Walter, Thomas J.; September 14, 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): NNC06CB81CWBS 463169.04.03.04.01.03
Copyright; Avail.: CASI: A02, Hardcopy
The U.S. Space Exploration Policy has established a vision for human exploration of the moon and Mars. One option for power for future outposts on the lunar and Martian surfaces is a nuclear reactor coupled with a free-piston Stirling convertor at a power level of 30-40 kWe. A 25 kW convertor was developed in the 1990s under the SP-100 program. This system consisted of two 12.5 kWe engines connected at their hot ends and mounted in tandem to cancel vibration. Recently, NASA began a new project with Auburn University to develop a 5 kWe, single convertor for use in such a possible lunar power system. Goals of this development program include a specific power in excess of 140 We/kg at the convertor level, lifetime in excess of five years and a control system that will safely manage the convertors in case of an emergency. Foster-Miller, Inc. is developing the 5 kWe Stirling Convertor Assembly. The characteristics of the design along with progress in developing the system will be described.
Author
STIRLING CYCLE; NUCLEAR REACTORS; SPACE POWER REACTORS; MARS BASES; PISTON ENGINES
20080047358 NASA Glenn Research Center, Cleveland, OH, United States
Extended Operation Testing of Stirling Convertors in Support of Stirling Radioisotope Power System Development
Lewandowski, Edward J.; Schreiber, Jeffre G.; Wilson, Scott D.; oriti, Salvatore M.; Cornell, Peggy; Schifer, Nicholas; July 28, 2008; In English; 6th International Energy Conversion Engineering Conference, 28-30 Jul. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 138494.04.01.01
Copyright; Avail.: CASI: A03, Hardcopy
100 We class Stirling convertors began extended operation testing at NASA Glenn Research Center (GRC) in 2003 with a pair of Technology Demonstration Convertors (TDCs) operating in air. Currently, the number of convertors on extended operation test has grown to 12, including both TDCs and Advanced Stirling Convertors (ASCs) operating both in air and in thermal vacuum. Additional convertors and an electrically heated radioisotope generator will be put on test in the near future. This testing has provided data to support life and reliability estimates and the quality improvements and design changes that have been made to the convertor. The convertors operated 24/7 at the nominal amplitude and power levels. Performance data were recorded on an hourly basis. Techniques to monitor the convertors for change in internal operation included gas analysis, vibration measurements and acoustic emission measurements. This data provided a baseline for future comparison. This paper summarizes the results of over 145,000 hours of TDC testing and 40,000 hours of ASC testing and discusses trends in the data. Data shows the importance of improved materials, hermetic sealing, and quality processes in maintaining convertor performance over long life.
Author
STIRLING CYCLE; ACOUSTIC EMISSION; VIBRATION MEASUREMENT; GAS ANALYSIS; SYSTEMS ENGINEERING
20080047360 NASA Glenn Research Center, Cleveland, OH, United States
Identifying Bearing Rotordynamic Coefficients using an Extended Kalman Filter
Miller, Brad A.; Howard, Samuel A.; [2008]; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNC06GA20GWBS 877868.02.07.03.01.01
Copyright; Avail.: CASI: A03, Hardcopy
An Extended Kalman Filter is developed to estimate the linearized direct and indirect stiffness and damping force coefficients for bearings in rotor-dynamic applications from noisy measurements of the shaft displacement in response to imbalance and impact excitation. The bearing properties are modeled as stochastic random variables using a Gauss-Markov model. Noise terms are introduced into the system model to account for all of the estimation error, including modeling errors and uncertainties and the propagation of measurement errors into the parameter estimates. The system model contains two user-defined parameters that can be tuned to improve the filter s performance; these parameters correspond to the covariance of the system and measurement noise variables. The filter is also strongly influenced by the initial values of the states and the error covariance matrix. The filter is demonstrated using numerically simulated data for a rotor-bearing system with two identical bearings, which reduces the number of unknown linear dynamic coefficients to eight. The filter estimates for the direct damping coefficients and all four stiffness coefficients correlated well with actual values, whereas the estimates for the cross-coupled damping coefficients were the least accurate.
Author
SHAFTS (MACHINE ELEMENTS); ROTOR DYNAMICS; KALMAN FILTERS; STIFFNESS; PARAMETER IDENTIFICATION; RANDOM VARIABLES; STOCHASTIC PROCESSES; ERROR ANALYSIS
20080047368 NASA Langley Research Center, Hampton, VA, United States
Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 4 - Phase 1 Implementation of the Concept Demonstrator
Abbott, David; Batten, Adam; Carpenter, David; Dunlop, John; Edwards, Graeme; Farmer, Tony; Gaffney, Bruce; Hedley, Mark; Hoschke, Nigel; Isaacs, Peter; Johnson, Mark; Lewis, Chris; Murdoch, Alex; Poulton, Geoff; Price, Don; Prokopenko, Mikhail; Rees, David; Scott, Andrew; Seneviratne, Sarath; Valencia, Philip; Wang, Peter; Whitnall, Denis; November 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 939904.05.07; PO L-71346D
Report No.(s): NASA/CR-2008-215542; Report No. TIPP 1898; Copyright; Avail.: CASI: A03, Hardcopy
This report describes the first phase of the implementation of the Concept Demonstrator. The Concept Demonstrator system is a powerful and flexible experimental test-bed platform for developing sensors, communications systems, and multi-agent based algorithms for an intelligent vehicle health monitoring system for deployment in aerospace vehicles. The Concept Demonstrator contains sensors and processing hardware distributed throughout the structure, and uses multi-agent algorithms to characterize impacts and determine an appropriate response to these impacts.
Author
SENSORS; SMART STRUCTURES; NONDESTRUCTIVE TESTS; AEROSPACE VEHICLES; QUALITY CONTROL; RESEARCH AND DEVELOPMENT
20080047371 NASA Stennis Space Center, Stennis Space Center, MS, United States
Coastal Marsh Monitoring for Persistent Saltwater Intrusion
Hall, Callie M.; October 28, 2008; In English; Mississippi-Alabama Bays and Bayous Symposium 2008, 28-29 Oct. 2008, Biloxi, MS, United States; Original contains color and black and white illustrations
Report No.(s): SSTI-2220-0174; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047371
This viewgraph presentation reviews NASA's work on the project that supports the Gulf of Mexico Alliance (GOMA) Governors Action Plan to monitor the coastal wetlands for saltwater intrusion. The action items that relate to the task are: (1) Obtain information on projected relative sea level rise, subsidence, and storm vulnerability to help prioritize conservation projects, including restoration, enhancement, and acquisition, and (2) Develop and apply ecosystem models to forecast the habitat structure and succession following hurricane disturbance and changes in ecological functions and services that impact vital socio-economic aspects of coastal systems. The objectives of the program are to provide resource managers with remote sensing products that support ecosystem forecasting models requiring salinity and inundation data. proposed work supports the habitat-switching modules in the Coastal Louisiana Ecosystem Assessment and Restoration (CLEAR) model, which provides scientific evaluation for restoration management.
CASI
COASTS; ECOSYSTEMS; ENVIRONMENT MODELS; INTRUSION; REMOTE SENSING; SEA LEVEL; SUBSIDENCE; WETLANDS; MARINE ENVIRONMENTS; COASTAL WATER
20080047372 NASA Glenn Research Center, Cleveland, OH, United States
Analysis of Thermal and Reaction Times for Hydrogen Reduction of Lunar Regolith
Hegde, U.; Balasubramaniam, R.; Gokoglu, S.; February 10, 2008; In English; STAIF-2008, 10-14 Feb. 2008, Albuquerque, NM, United States; Original contains black and white illustrations
Contract(s)/Grant(s): NCC3-975WBS 387498.04.01.04.03
Copyright; Avail.: CASI: A02, Hardcopy
System analysis of oxygen production by hydrogen reduction of lunar regolith has shown the importance of the relative time scales for regolith heating and chemical reaction to overall performance. These values determine the sizing and power requirements of the system and also impact the number and operational phasing of reaction chambers. In this paper, a Nusselt number correlation analysis is performed to determine the heat transfer rates and regolith heat up times in a fluidized bed reactor heated by a central heating element (e.g., a resistively heated rod, or a solar concentrator heat pipe). A coupled chemical and transport model has also been developed for the chemical reduction of regolith by a continuous flow of hydrogen. The regolith conversion occurs on the surfaces of and within the regolith particles. Several important quantities are identified as a result of the above analyses. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the particle Reynolds number, the Archimedes number, and the time needed for hydrogen to diffuse into the pores of the regolith particles. The analysis is used to determine the heat up and reaction times and its application to NASA s oxygen production system modeling tool is noted.
Author
REGOLITH; LUNAR ROCKS; CHEMICAL REACTIONS; CONTINUUM FLOW; HEAT TRANSFER
20080047373 NASA Glenn Research Center, Cleveland, OH, United States
NASA's In-Space Propulsion Technology Project Overview, Near-term Products and Mission Applicability
Dankanich, John; Anderson, David J.; August 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07QA54DWBS 346620.01.03.01
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047373
The In-Space Propulsion Technology (ISPT) Project, funded by NASA's Science Mission Directorate (SMD), is continuing to invest in propulsion technologies that will enable or enhance NASA robotic science missions. This overview provides development status, near-term mission benefits, applicability, and availability of in-space propulsion technologies in the areas of aerocapture, electric propulsion, advanced chemical thrusters, and systems analysis tools. Aerocapture investments improved (1) guidance, navigation, and control models of blunt-body rigid aeroshells, 2) atmospheric models for Earth, Titan, Mars and Venus, and 3) models for aerothermal effects. Investments in electric propulsion technologies focused on completing NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system. The project is also concluding its High Voltage Hall Accelerator (HiVHAC) mid-term product specifically designed for a low-cost electric propulsion option. The primary chemical propulsion investment is on the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. The project is also delivering products to assist technology infusion and quantify mission applicability and benefits through mission analysis and tools. In-space propulsion technologies are applicable, and potentially enabling for flagship destinations currently under evaluation, as well as having broad applicability to future Discovery and New Frontiers mission solicitations.
Author
PROPULSION SYSTEM CONFIGURATIONS; ION PROPULSION; LIQUID ROCKET PROPELLANTS; CHEMICAL PROPULSION; AEROTHERMODYNAMICS; ELECTRIC PROPULSION; TEMPERATURE EFFECTS; ROCKET ENGINES; PROPULSION SYSTEM PERFORMANCE
Additions to the NASA Aeronautics and Space Database as of 12/31/2008
20080047408 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Parameter Estimation using Numerical Merger Waveforms
Thorpe, J. I.; McWilliams, S.; Kelly, B.; Fahey, R.; Arnaud, K.; Baker, J.; June 16, 2008; In English; 7th International LISA Symposium/Space Sciences Institute of Catalonia, 16-20 Jun. 2008, Barcelona, Spain; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNH06CC03B
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047408
Results: Developed parameter estimation model integrating complete waveforms and improved instrumental models. Initial results for equal-mass non-spinning systems indicate moderate improvement in most parameters, significant improvement in some Near-term improvement: a) Improved statistics; b) T-channel; c) Larger parameter space coverage. Combination with other results: a) Higher harmonics; b) Spin precession; c) Instrumental effects.
Derived from text
PARAMETER IDENTIFICATION; WAVEFORMS; ESTIMATING
20080047410 NASA Goddard Space Flight Center, Greenbelt, MD, United States; Thinking Systems, Inc., Tucson, AZ, United States
General Mission Analysis Tool (GMAT) User's Guide (Draft)
Hughes, Steven P.; July 12, 2007; In English; Original contains black and white illustrations
No Copyright; Avail.: CASI: A05, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047410
4The General Mission Analysis Tool (GMAT) is a space trajectory optimization and mission analysis system. This document is a draft of the users guide for the tool. Included in the guide is information about Configuring Objects/Resources, Object Fields: Quick Look-up Tables, and Commands and Events.
CASI
TRAJECTORY OPTIMIZATION; COMPUTER PROGRAMS; ON-LINE SYSTEMS; SPACECRAFT TRAJECTORIES
20080047411 NASA Glenn Research Center, Cleveland, OH, United States
Radioisotope Power: A Key Technology for Deep Space Exploration
Schmidt, George; Sutliff, Tom; Dudzinski, Leonard; September 28, 2008; In English; 59th International Astronautical Congress, 28 Sep. - 3 Oct. 2008, Glasglow, Scotland, United Kingdom; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047411
A Radioisotope Power System (RPS) generates power by converting the heat released from the nuclear decay of radioactive isotopes, such as Plutonium-238 (Pu-238), into electricity. First used in space by the U.S. in 1961, these devices have enabled some of the most challenging and exciting space missions in history, including the Pioneer and Voyager probes to the outer solar system; the Apollo lunar surface experiments; the Viking landers; the Ulysses polar orbital mission about the Sun; the Galileo mission to Jupiter; the Cassini mission orbiting Saturn; and the recently launched New Horizons mission to Pluto. Radioisotopes have also served as a versatile heat source for moderating equipment thermal environments on these and many other missions, including the Mars exploration rovers, Spirit and Opportunity. The key advantage of RPS is its ability to operate continuously, independent of orientation and distance relative to the Sun. Radioisotope systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, autonomous operations in the extreme conditions of space and other planetary bodies. This paper reviews the history of RPS for the U.S. space program. It also describes current development of a new Stirling cycle-based generator that will greatly expand the application of nuclear-powered missions in the future.
Author
RADIOACTIVE ISOTOPES; STIRLING CYCLE; PLUTONIUM 238; THERMAL ENVIRONMENTS; HEAT SOURCES; ELECTRICITY
20080047412 NASA Glenn Research Center, Cleveland, OH, United States
Crack Growth Properties of Sealing Glasses
Salem, Jonathan A.; Tandon, R.; October 06, 2008; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 510505.06.03.04.99
Copyright; Avail.: CASI: A03, Hardcopy
The crack growth properties of several sealing glasses were measured using constant stress rate testing in 2% and 95% RH (relative humidity). Crack growth parameters measured in high humidity are systematically smaller (n and B) than those measured in low humidity, and velocities for dry environments are approx. 100x lower than for wet environments. The crack velocity is very sensitivity to small changes in RH at low RH. Confidence intervals on parameters that were estimated from propagation of errors were comparable to those from Monte Carlo simulation.
Author
CRACK PROPAGATION; GLASS; SEALING; HUMIDITY; CERAMICS
20080047414 NASA Glenn Research Center, Cleveland, OH, United States
100-LBF LO2/LCH4 - Reaction Control Engine Technology Development for Future Space Vehicles
Robinson, Philip J.; Veith, Eric M.; Hurlbert, Eric A.; Jimenez, Rafael; Smith, Timothy D.; September 29, 2008; In English; International Astronautical Federation, 29 Sep. 3 Oct. 2008, Glasgow, Scotland, United Kingdom; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06CB64CWBS 253225.01.03
Copyright; Avail.: CASI: A03, Hardcopy
The National Aeronautics and Space Administration (NASA) has identified liquid oxygen (LO2)/liquid methane (LCH4) propulsion systems as promising options for some future space vehicles. NASA issued a contract to Aerojet to develop a 100-lbf (445 N) LO2/LCH4 Reaction Control Engine (RCE) aimed at reducing the risk of utilizing a cryogenic reaction control system (RCS) on a space vehicle. Aerojet utilized innovative design solutions to develop an RCE that can ignite reliably over a broad range of inlet temperatures, perform short minimum impulse bits (MIB) at small electrical pulse widths (EPW), and produce excellent specific impulse (Isp) across a range of engine mixture ratios (MR). These design innovations also provide a start transient with a benign MR, ensuring good thrust chamber compatibility and long life. In addition, this RCE can successfully operate at MRs associated with main engines, enabling the RCE to provide emergency backup propulsion to minimize vehicle propellant load and overall system mass.
Author
LIQUID OXYGEN; PROPULSION SYSTEM CONFIGURATIONS; ENGINE DESIGN; LIQUEFIED GASES; SPECIFIC IMPULSE; METHANE; CRYOGENICS; PROPELLANTS; PROPULSION SYSTEM PERFORMANCE
20080047415 Cleveland State Univ., Cleveland, OH, United States
Multiplexed Predictive Control of a Large Commercial Turbofan Engine
Richter, hanz; Singaraju, Anil; Litt, Jonathan S.; AIAA Journal of Guidance, Control, and Dynamics; March 2008; ISSN 0731-5090; vol. Volume 31; issue No. 2; pp. 273-28; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNC05GA73G
Copyright; Avail.: CASI: A02, Hardcopy
Model predictive control is a strategy well-suited to handle the highly complex, nonlinear, uncertain, and constrained dynamics involved in aircraft engine control problems. However, it has thus far been infeasible to implement model predictive control in engine control applications, because of the combination of model complexity and the time allotted for the control update calculation. In this paper, a multiplexed implementation is proposed that dramatically reduces the computational burden of the quadratic programming optimization that must be solved online as part of the model-predictive-control algorithm. Actuator updates are calculated sequentially and cyclically in a multiplexed implementation, as opposed to the simultaneous optimization taking place in conventional model predictive control. Theoretical aspects are discussed based on a nominal model, and actual computational savings are demonstrated using a realistic commercial engine model.
Author
TURBOFAN ENGINES; AIRCRAFT CONTROL; ENGINE CONTROL; ENGINE DESIGN; ACTUATORS
20080047417 NASA Glenn Research Center, Cleveland, OH, United States
Evaluation of Silicon-on-Insulator HTOP-01 Operational Amplifier for Wide Temperature Operation
Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik; June 16, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07B; EXCX2208D
Copyright; Avail.: CASI: A02, Hardcopy
Electronics capable of operation under extreme temperatures are required in many of NASA space exploration missions. Aerospace and military applications, as well as some terrestrial industries constitute environments where electronic systems are anticipated to be exposed to extreme temperatures and wide-range thermal swings. Electronics that are able to withstand and operate efficiently in such harsh environments would simplify, if not eliminate, traditional thermal control elements and their associated structures for proper ambient operation. As a result, overall system mass would be reduced, design would be simplified, and reliability would be improved. Electronic parts that are built utilizing silicon-on-insulator (SOI) technology are known to offer better radiation-tolerance compared to their conventional silicon counterparts, provide faster switching, and consume less power. They also exhibit reduced leakage current and, thus, they are often tailored for high temperature operation. These attributes make SOI-based devices suitable for use in harsh environments where extreme temperatures and wide thermal swings are anticipated. A new operational amplifier, based on silicon-on-insulator technology and geared for high temperature well-logging applications, was recently introduced by Honeywell Corporation. This HTOP-01 dual precision operational amplifier is a low power device, operates on a single supply, and has an internal oscillator and an external clocking option [1]. It is rated for operation from -55 C to +225 C with a maximum output current capability of 50 mA. The amplifier chip is designed as a 14-pin, hermetically-sealed device in a ceramic package. Table I shows some of the device manufacturer s specifications.
Author
OSCILLATORS; TEMPERATURE CONTROL; RADIATION TOLERANCE; OPERATIONAL AMPLIFIERS; SOI (SEMICONDUCTORS); HIGH TEMPERATURE; MILITARY TECHNOLOGY; SILICON
20080047418 NASA Glenn Research Center, Cleveland, OH, United States
High Temperature, Permanent Magnet Biased, Fault Tolerant, Homopolar Magnetic Bearing Development
Palazzolo, Alan; Tucker, Randall; Kenny, Andrew; Kang, Kyung-Dae; Ghandi, Varun; Liu, Jinfang; Choi, Heeju; Provenza, Andrew; June 09, 2008; In English; ASME Turbo Expo 2008: Power for Land, Sea and Air, 9-13 Jun. 2008, Berlin, Germany; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06CA04CWBS 561581.02.08.03.15.03
Report No.(s): GT2008-50917; Copyright; Avail.: CASI: A03, Hardcopy
This paper summarizes the development of a magnetic bearing designed to operate at 1,000 F. A novel feature of this high temperature magnetic bearing is its homopolar construction which incorporates state of the art high temperature, 1,000 F, permanent magnets. A second feature is its fault tolerance capability which provides the desired control forces with over one-half of the coils failed. The construction and design methodology of the bearing is outlined and test results are shown. The agreement between a 3D finite element, magnetic field based prediction for force is shown to be in good agreement with predictions at room and high temperature. A 5 axis test rig will be complete soon to provide a means to test the magnetic bearings at high temperature and speed.
Author
MAGNETIC BEARINGS; PERMANENT MAGNETS; HIGH TEMPERATURE; FAULT TOLERANCE; FINITE ELEMENT METHOD; MAGNETIC FIELDS
20080047419 NASA Glenn Research Center, Cleveland, OH, United States
Influence of Test Procedures on the Thermomechanical Properties of a 55NiTi Shape Memory Alloy
Padula, Santo A., II; Gaydosh, Darrell J.; Noebe, Ronald D.; Bigelow, Glen S.; Garg, Anita; Lagoudas, Dimitris; Karaman, Ibrahim; Atli, Kadri C.; March 09, 2008; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.02
Copyright; Avail.: CASI: A03, Hardcopy
Over the past few decades, binary NiTi shape memory alloys have received attention due to their unique mechanical characteristics, leading to their potential use in low-temperature, solid-state actuator applications. However, prior to using these materials for such applications, the physical response of these systems to mechanical and thermal stimuli must be thoroughly understood and modeled to aid designers in developing SMA-enabled systems. Even though shape memory alloys have been around for almost five decades, very little effort has been made to standardize testing procedures. Although some standards for measuring the transformation temperatures of SMA s are available, no real standards exist for determining the various mechanical and thermomechanical properties that govern the usefulness of these unique materials. Consequently, this study involved testing a 55NiTi alloy using a variety of different test methodologies. All samples tested were taken from the same heat and batch to remove the influence of sample pedigree on the observed results. When the material was tested under constant-stress, thermal-cycle conditions, variations in the characteristic material responses were observed, depending on test methodology. The transformation strain and irreversible strain were impacted more than the transformation temperatures, which only showed an affect with regard to applied external stress. In some cases, test methodology altered the transformation strain by 0.005-0.01mm/mm, which translates into a difference in work output capability of approximately 2 J/cu cm (290 in!lbf/cu in). These results indicate the need for the development of testing standards so that meaningful data can be generated and successfully incorporated into viable models and hardware. The use of consistent testing procedures is also important when comparing results from one research organization to another. To this end, differences in the observed responses will be presented, contrasted and rationalized, in hopes of eventually developing standardized testing procedures for shape memory alloys.
Author
NICKEL ALLOYS; TITANIUM ALLOYS; SHAPE MEMORY ALLOYS; THERMODYNAMICS; ACTUATORS; MECHANICAL PROPERTIES; BINARY ALLOYS
20080047420 NASA Glenn Research Center, Cleveland, OH, United States
Oxidation of ZrB2 SiC TaSi2 Materials at Ultra High Temperatures
Opila, E.; Smith, J.; Levine, S.; Lorincz, J.; Reigel, M.; August 05, 2008; In English; Ultra-High Temperature Ceramics Conference, 5 Aug. 2008, Lake Tahoe, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.03.02.04.01
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047420
ZrB2 - 20v% SiC - 20v% TaSi2 was oxidized in stagnant air for ten minute cycles for times up to 100 minutes at 1627 C and 1927 C. The sample oxidized at 1627 C showed oxidation resistance better than that of the standard ZrB2 - 20v% SiC. The sample oxidized at 1927 C, however, showed evidence of liquid phase formation and complex oxidation products. The sample exposed at 1927 C was analyzed in detail by scanning electron microprobe and wavelength dispersive spectroscopy to understand the complex oxidation and melting reactions occurring during exposure. The as hot-pressed material shows the formation of a Zr(Ta)B2 phase in addition to the three phases in the nominal composition already noted. After oxidation, the TaSi2 in the matrix was completely reacted to form Ta(Zr)C. The layered oxidation products included SiO2, ZrO2, Ta2O5, and a complex oxide containing both Zr and Ta. Likely reactions are proposed based on thermodynamic phase stability and phase morphology.
Author
ZIRCONIUM OXIDES; SILICON DIOXIDE; OXIDATION RESISTANCE; HIGH TEMPERATURE; LIQUID PHASES; HOT PRESSING; THERMODYNAMICS
20080047421 NASA Glenn Research Center, Cleveland, OH, United States
Separating Turbofan Engine Noise Sources Using Auto and Cross Spectra from Four Microphones
Miles, Jeffrey Hilton; AIAA Journal; January 2008; vol. Volume 46; issue No. 1; pp. 61-7; In English; 12th AIAA/CEAS Aeroacoustics Conference, 8-10 May 2008, Cambridge, MA, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.18.03
Report No.(s): Paper 2580; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047421
http://dx.doi.org/10.2514/1.25177
The study of core noise from turbofan engines has become more important as noise from other sources such as the fan and jet were reduced. A multiple-microphone and acoustic-source modeling method to separate correlated and uncorrelated sources is discussed. The auto- and cross spectra in the frequency range below 1000 Hz are fitted with a noise propagation model based on a source couplet consisting of a single incoherent monopole source with a single coherent monopole source or a source triplet consisting of a single incoherent monopole source with two coherent monopole point sources. Examples are presented using data from a Pratt& Whitney PW4098 turbofan engine. The method separates the low-frequency jet noise from the core noise at the nozzle exit. It is shown that at low power settings, the core noise is a major contributor to the noise. Even at higher power settings, it can be more important than jet noise. However, at low frequencies, uncorrelated broadband noise and jet noise become the important factors as the engine power setting is increased.
Author
ENGINE NOISE; JET AIRCRAFT NOISE; SOUND GENERATORS; TURBOFAN ENGINES; NOISE PROPAGATION; MICROPHONES; MONOPOLES; COHERENT RADIATION
20080047422 NASA Glenn Research Center, Cleveland, OH, United States
Time Delay Analysis of Turbofan Engine Direct and Indirect Combustion Noise Sources
Miles, Jeffrey Hilton; May 08, 2008; In English; AARC Turbine Noise Workshop, 8-0 May 2008, Vancouver, BC, Canada; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.18.03
Report No.(s): AIAA-2008-50; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047422
The core noise components of a dual spool turbofan engine were separated by the use of a coherence function. A source location technique based on adjusting the time delay between the combustor pressure sensor signal and the far-field microphone signal to maximize the coherence and remove as much variation of the phase angle with frequency as possible was used. The discovery was made that for the 130o microphone a 90.027 ms time shift worked best for the frequency band from 0 to 200 Hz while a 86.975 ms time shift worked best for the frequency band from 200 to 400 Hz. Hence, the 0 to 200 Hz band signal took more time than the 200 to 400 Hz band signal to travel the same distance. This suggests the 0 to 200 Hz coherent cross spectral density band is partly due to indirect combustion noise attributed to entropy fluctuations, which travel at the flow velocity, interacting with the turbine. The signal in the 200 to 400 Hz frequency band is attributed mostly to direct combustion noise. Results are presented herein for engine power settings of 48, 54, and 60 percent of the maximum power setting
Author
TURBOFAN ENGINES; TIME LAG; ENGINE NOISE; PRESSURE SENSORS; FAR FIELDS; MICROPHONES; COMBUSTION
20080047424 NASA Glenn Research Center, Cleveland, OH, United States
Aromatic Diimides - Potential Dyes for Use in Smart Films and Fibers
Meador, Michael A.; Tyson, Daniel S.; Ilhan, Faysal; Carbaugh, Ashley; June 03, 2008; In English; Advances in Colorants, Chemicals, Finishes and Fibrous Materials Symposium, 3-4 Jun. 2008, Greenville, SC, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07BA13BWBS 561581.02.10.03.06
Copyright; Avail.: CASI: A03, Hardcopy
New aromatic diimide fluorescent dyes have been prepared with potential for use as chemical sensors and in chromogenic polymers. These dyes have been designed to utilize excited state electron transfer reactions as the means for sensing chemical species. For example, an aniline en-dcapped anthryl diimides functions effectively as an "on-off" sensor for pH and the detection of phosphoryl halide based chemical warfare agents, such as Sarin. In the absence of analytes, fluorescence from this dye is completely quenched by excited state electron transfer from the terminal amines. Reaction of these amines inhibits electron transfer and activates the fluorescence of the dye. Another substituted anthryl diimide is presented with the capability to detect pH and nitroaromatic compounds, such as TNT. Films prepared by doping small amounts (less than 0.1 weight percent) of several of these dyes in polymers such as linear low density polyethylene exhibit thermochromism. At room temperature, these films fluoresce reddish-orange. Upon heating, the fluorescence turns green. This process is reversible cooling the films to room temperature restores the orange emission.
Author
DYES; AROMATIC COMPOUNDS; SMART MATERIALS; FLUORESCENCE; CHEMICAL WARFARE
20080047425 NASA Glenn Research Center, Cleveland, OH, United States
Polymeric Materials for Aerospace Power and Propulsion-NASA Glenn Overview
Meador, Michael A.; February 04, 2008; In English; High Temple Workshop, 4-7 Feb. 2008, Savannah, GA, FROM; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.10.03.06
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047425
Use of lightweight materials in aerospace power and propulsion components can lead to significant reductions in vehicle weight and improvements in performance and efficiency. Polymeric materials are well suited for many of these applications, but improvements in processability, durability and performance are required for their successful use in these components. Polymers Research at NASA Glenn is focused on utilizing a combination of traditional polymer science and engineering approaches and nanotechnology to develop new materials with enhanced processability, performance and durability. An overview of these efforts will be presented.
Author
NANOTECHNOLOGY; SPACECRAFT PROPULSION; ENGINE PARTS; WEIGHT REDUCTION; POLYMERS
20080047426 NASA Glenn Research Center, Cleveland, OH, United States
New Frontiers AO: Advanced Materials Bi-propellant Rocket (AMBR) Engine Information Summary
Liou, Larry C.; August 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 346620.01.03.01
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047426
The Advanced Material Bi-propellant Rocket (AMBR) engine is a high performance (I(sub sp)), higher thrust, radiation cooled, storable bi-propellant space engine of the same physical envelope as the High Performance Apogee Thruster (HiPAT(TradeMark)). To provide further information about the AMBR engine, this document provides details on performance, development, mission implementation, key spacecraft integration considerations, project participants and approach, contact information, system specifications, and a list of references. The In-Space Propulsion Technology (ISPT) project team at NASA Glenn Research Center (GRC) leads the technology development of the AMBR engine. Their NASA partners were Marshall Space Flight Center (MSFC) and Jet Propulsion Laboratory (JPL). Aerojet leads the industrial partners selected competitively for the technology development via the NASA Research Announcement (NRA) process.
Author
LIQUID ROCKET PROPELLANTS; ROCKET ENGINES; THRUST; HIGH THRUST; APOGEES
20080047428 NASA Glenn Research Center, Cleveland, OH, United States
Risk Assessment of Bone Fracture During Space Exploration Missions to the Moon and Mars
Lewandowski, Beth E.; Myers, Jerry G.; Nelson, Emily S.; Griffin, Devon; February 26, 2008; In English; Space Systems Engineering and Risk Management Symposium, 27-29 Feb. 2008, Los Angeles, CA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 444543.01.02.01
Copyright; Avail.: CASI: A03, Hardcopy
The possibility of a traumatic bone fracture in space is a concern due to the observed decrease in astronaut bone mineral density (BMD) during spaceflight and because of the physical demands of the mission. The Bone Fracture Risk Module (BFxRM) was developed to quantify the probability of fracture at the femoral neck and lumbar spine during space exploration missions. The BFxRM is scenario-based, providing predictions for specific activities or events during a particular space mission. The key elements of the BFxRM are the mission parameters, the biomechanical loading models, the bone loss and fracture models and the incidence rate of the activity or event. Uncertainties in the model parameters arise due to variations within the population and unknowns associated with the effects of the space environment. Consequently, parameter distributions were used in Monte Carlo simulations to obtain an estimate of fracture probability under real mission scenarios. The model predicts an increase in the probability of fracture as the mission length increases and fracture is more likely in the higher gravitational field of Mars than on the moon. The resulting probability predictions and sensitivity analyses of the BFxRM can be used as an engineering tool for mission operation and resource planning in order to mitigate the risk of bone fracture in space.
Author
RISK ASSESSMENT; BONE DEMINERALIZATION; FRACTURING; SENSITIVITY ANALYSIS; AEROSPACE ENVIRONMENTS
20080047429 NASA Glenn Research Center, Cleveland, OH, United States
Further Developments in Modeling Creep Effects Within Structural SiC/SiC Components
Lang, Jerry; DiCarlo, James A.; January 30, 2008; In English; 32nd Annual Conference Composites Materials and Structures, 27 Jan. - 1 Feb. 2008, Daytona Beach, Fl, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.16.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047429
Anticipating the implementation of advanced SiC/SiC composites into turbine section components of future aero-propulsion engines, the primary objective of this on-going study is to develop physics-based analytical and finite-element modeling tools to predict the effects of constituent creep on SiC/SiC component service life. A second objective is to understand how to possibly manipulate constituent materials and processes in order to minimize these effects. Focusing on SiC/SiC components experiencing through-thickness stress gradients (e.g., airfoil leading edge), prior NASA creep modeling studies showed that detrimental residual stress effects can develop globally within the component walls which can increase the risk of matrix cracking. These studies assumed that the SiC/SiC composites behaved as isotropic viscoelastic continuum materials with creep behavior that was linear and symmetric with stress and that the creep parameters could be obtained from creep data as experimentally measured in-plane in the fiber direction of advanced thin-walled 2D SiC/SiC panels. The present study expands on those prior efforts by including constituent behavior with non-linear stress dependencies in order to predict such key creep-related SiC/SiC properties as time-dependent matrix stress, constituent creep and content effects on composite creep rates and rupture times, and stresses on fiber and matrix during and after creep.
Author
COMPOSITE MATERIALS; SILICON CARBIDES; CREEP PROPERTIES; STRUCTURAL DESIGN; VISCOELASTICITY; TURBINES; FINITE ELEMENT METHOD; AIRCRAFT ENGINES
20080047431 NASA Glenn Research Center, Cleveland, OH, United States
Mars Exploration Rovers: 4 Years on Mars
Landis, Geoffrey A.; January 18, 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 361426.07.03
No Copyright; Avail.: CASI: A05, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047431
This January, the Mars Exploration Rovers "Spirit" and "Opportunity" are starting their fifth year of exploring the surface of Mars, well over ten times their nominal 90-day design lifetime. This lecture discusses the Mars Exploration Rovers, presents the current mission status for the extended mission, some of the most results from the mission and how it is affecting our current view of Mars, and briefly presents the plans for the coming NASA missions to the surface of Mars and concepts for exploration with robots and humans into the next decade, and beyond.
Author
MARS EXPLORATION; MARS SURFACE; ROVING VEHICLES
20080047432 Army Research Lab., Cleveland, OH, United States
An Experimental Study of Fretting of Gear Teeth
Krantz, Timothy L.; May 21, 2008; In English; STLE 2008 Annual Meeting of the Society of Tribologists and Lubrication Engineers, 21 May 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 510505.01.03.01.08
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047432
Experiments were conducted to study fretting of gears. The gears were made from case-carburized AISI 9310 alloy to match the material of a flight actuator gearbox of interest. The objective of the testing was to produce damage representative of that observed on flight hardware. The following correlations and observations were noted. The amplitude of dithering motion very strongly influenced the type and magnitude of damage. Sliding amounts on the order of 30% of the width of the line contact were judged to most readily produce fretting damage. There was observed an incubation period on the order of tens-of-thousands of cycles, and the incubation period was influenced by surface roughness, torque, and the motion extent. Fretting damage could be produced for any of the torques tested, and the severity of damage increased slightly with torque. Gear teeth having surface roughness of 0.7-0.8 micrometer were somewhat more resistant to fretting than were smoother surfaces.
Author
FRETTING; TRANSMISSIONS (MACHINE ELEMENTS); SURFACE ROUGHNESS; GEARS; TORQUE; CARBURIZING
20080047434 NASA Glenn Research Center, Cleveland, OH, United States
State of Jet Noise Prediction-NASA Perspective
Bridges, James E.; October 07, 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.17.03
Copyright; Avail.: CASI: A03, Hardcopy
This presentation covers work primarily done under the Airport Noise Technical Challenge portion of the Supersonics Project in the Fundamental Aeronautics Program. To provide motivation and context, the presentation starts with a brief overview of the Airport Noise Technical Challenge. It then covers the state of NASA s jet noise prediction tools in empirical, RANS-based, and time-resolved categories. The empirical tools, requires seconds to provide a prediction of noise spectral directivity with an accuracy of a few dB, but only for axisymmetric configurations. The RANS-based tools are able to discern the impact of three-dimensional features, but are currently deficient in predicting noise from heated jets and jets with high speed and require hours to produce their prediction. The time-resolved codes are capable of predicting resonances and other time-dependent phenomena, but are very immature, requiring months to deliver predictions without unknown accuracies and dependabilities. In toto, however, when one considers the progress being made it appears that aeroacoustic prediction tools are soon to approach the level of sophistication and accuracy of aerodynamic engineering tools.
Author
AIRCRAFT NOISE; JET AIRCRAFT NOISE; NOISE PREDICTION; SUPERSONICS; AEROACOUSTICS
20080047436 NASA Glenn Research Center, Cleveland, OH, United States
Acting on Lessons Learned: A NASA Glenn Acoustics Branch Perspective
Koch, L. Danielle; April 02, 2008; In English; Quiet, Efficient Fans for Spaceflight Workshop, 2 Apr. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 439906.04.01.02.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047436
Lessons learned from the International Space Station have indicated that early attention to acoustics will be key to achieving safer, more productive environments for new long duration missions. Fans are known to be dominant noise sources, and reducing fan noise poses challenges for fan manufacturers and systems engineers. The NASA Glenn Acoustics Branch has considered ways in which expertise and capabilities traditionally used to understand and mitigate aircraft engine noise can be used to address small fan noise issues in Exploration and Information Technology applications. Many could benefit if NASA can capture what is known about small fan aero and acoustic performance in a "Guide for the Design, Selection, and Installation of Fans for Spaceflight Applications." A draft outline for this document will be offered as a useful starting point for brainstorming ideas for the various smaller, near-term research projects that would need to be addressed first.
Author
ACOUSTIC PROPERTIES; AEROACOUSTICS; AERODYNAMIC NOISE; NOISE REDUCTION; LESSONS LEARNED; INTERNATIONAL SPACE STATION
20080047437 NASA Glenn Research Center, Cleveland, OH, United States
Jet Mixing Noise Scaling Laws SHJAR Data Vs. Predictions
Khavaran, Abbas; Bridges, James; September 23, 2008; In English; Acoustic Technical Working Group, 23-24 Sep. 2008, Williamsburg, VA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.18.03
Copyright; Avail.: CASI: A03, Hardcopy
High quality jet noise spectral data measured at the anechoic dome at the NASA Glenn Research Center is used to examine a number of jet noise scaling laws. Configurations considered in the present study consist of convergent as well as convergent-divergent axisymmetric nozzles. The spectral measurements are shown in narrow band and cover 8193 equally spaced points in a typical Strouhal number range of (0.01 10.0). Measurements are reported as lossless (i.e. atmospheric attenuation is added to as-measured data), and at 24 equally spaced angles (50deg to 165deg) on a 100-diameter arc. Following the work of Viswanathan [Ref. 1], velocity power laws are derived using a least square fit on spectral power density as a function of jet temperature and observer angle. The goodness of the fit is studied at each angle, and alternative relationships are proposed to improve the spectral collapse when certain conditions are met. On the application side, power laws are extremely useful in identifying components from various noise generation mechanisms. From this analysis, jet noise prediction tools can be developed with physics derived from the different spectral components.
Author
JET MIXING FLOW; JET AIRCRAFT NOISE; NOISE GENERATORS; NOISE PREDICTION; SCALING LAWS; SPECTRUM ANALYSIS; ACOUSTIC PROPERTIES; AEROACOUSTICS; AERODYNAMIC NOISE
20080047438 NASA Glenn Research Center, Cleveland, OH, United States
NASA Clean-Sheet Fans: Design, Build Analyze, Test, and Report
Koch, L. Danielle; April 02, 2008; In English; Quiet, Efficient Fans for Spaceflight Workshop, 2-4 Apr. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 439906.04.01.02.03
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047438
A suggested topic in small fan research is presented. Presentation briefly describes the scope of an effort to design, build and test a ventilation class cooling fan. Comments are included for the following categories: information (available and needed), benefits and values, concerns, variations and alternatives, and interest.
Author
COOLING SYSTEMS; VENTILATION FANS
20080047439 NASA Glenn Research Center, Cleveland, OH, United States
Supersonics Project: Airport Noise Technical Challenge
Bridges, James E.; September 23, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.17.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047439
This presentation gives an overview of the work being done under the Airport Noise Technical Challenge portion of the Supersonics Project in the Fundamental Aeronautics Program. The objective of the Challenge is to provide technology (e.g. low noise nozzle concepts) and engineering tools required for a viable supersonic aircraft. To accomplish this we have activities divided into Prediction, Diagnostics, and Engineering elements. Each of the tasks reviewed here have potential applications to work being done at other flight regimes and other aircraft and are of interest to the Acoustics Technical Working Group.
Author
AIRCRAFT NOISE; LOW NOISE; DIAGNOSIS; ACOUSTICS
20080047440 NASA Glenn Research Center, Cleveland, OH, United States
Propulsion and Cryogenics Advanced Development (PCAD) Project Propulsion Technologies for the Lunar Lander
Klem, Mark D.; Smith, Timothy D.; February 12, 2008; In English; 6th Space Technology and Applications International Forum: Space Colonization, 10-14 Feb. 2008, Albuquerque, NM, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047440
The Propulsion and Cryogenics Advanced Development (PCAD) Project in the Exploration Technology Development Program is developing technologies as risk mitigation for Orion and the Lunar Lander. An integrated main and reaction control propulsion system has been identified as a candidate for the Lunar Lander Ascent Module. The propellants used in this integrated system are Liquid Oxygen (LOX)/Liquid Methane (LCH4) propellants. A deep throttle pump fed Liquid Oxygen (LOX)/Liquid Hydrogen (LH2) engine system has been identified for the Lunar Lander Descent Vehicle. The propellant combination and architecture of these propulsion systems are novel and would require risk reduction prior to detailed design and development. The PCAD Project addresses the technology requirements to obtain relevant and necessary test data to further the technology maturity of propulsion hardware utilizing these propellants. This plan and achievements to date will be presented.
Author
LUNAR MODULE; PROPULSION SYSTEM CONFIGURATIONS; LIQUID OXYGEN; HYDROGEN OXYGEN ENGINES; CRYOGENICS; SYSTEMS INTEGRATION; LIQUEFIED GASES
20080047441 Auburn Univ., AL, United States
The Development of a Control System for a 5 Kilowatt Free Piston Stirling Engine Convertor
Kirby, Raymond L.; Vitale, Nick; July 28, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06CB81CWBS 463169.04.03.04.01.03
Copyright; Avail.: CASI: A02, Hardcopy
The new NASA Vision for Exploration, announced by President Bush in January 2004, proposes an ambitious program that plans to return astronauts to the moon by the 2018 time frame. A recent NASA study entitled "Affordable Fission Surface Power Study" recommended a 40 kWe, 900 K, NaK-cooled, Stirling convertors for 2020 launch. Use of two of the nominal 5 kW convertors allows the system to be dynamically balanced. A group of four dual-convertor combinations that would yield 40 kWe can be tested to validate the viability of Stirling technology for space fission surface power systems. The work described in this paper deals specifically with the control system for the 5 kW convertor described in the preceding paragraph. This control system is responsible for maintaining piston stroke to a setpoint in the presence of various disturbances including electrical load variations. Pulse starting of the Free Piston Stirling Engine (FPSE) convertor is also an inherent part of such a control system. Finally, the ability to throttle the engine to match the required output power is discussed in terms of setpoint control. Several novel ideas have been incorporated into the piston stroke control strategy that will engender a stable response to disturbances in the presence of midpoint drift while providing useful data regarding the position of both the power piston and displacer.
Author
STIRLING CYCLE; SPACECRAFT POWER SUPPLIES; FREE-PISTON ENGINES; STIRLING ENGINES; LOADS (FORCES)
20080047442 NASA Glenn Research Center, Cleveland, OH, United States
Application of the Iridium Satellite System to Aeronautical Communications
Kerczewski, Robert J.; Meza, Mike; Gupta, Om; September 24, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 659877.02.03.0606.01
Copyright; Avail.: CASI: A02, Hardcopy
The next generation air transportation system will require greater air-ground communications capacity to accommodate more air traffic with increased safety and efficiency. Communications will remain primarily terrestrially based, but satellite communications will have an increased role. Inmarsat s aeronautical services have been approved and are in use for aeronautical safety communications provided by geostationary satellites. More recently the approval process for the Iridium low earth orbit constellation is nearing completion. The current Iridium system will be able to provide basic air traffic services communications suitable for oceanic, remote and polar regions. The planned second generation of the Iridium system, called Iridium NEXT, will provide enhanced capabilities and enable a greater role in the future of aeronautical communications. This paper will review the potential role of satellite communications in the future of air transportation, the Iridium approval process and relevant system testing, and the potential role of Iridium NEXT.
Author
AIR TRANSPORTATION; SYNCHRONOUS PLATFORMS; SATELLITE COMMUNICATION; LOW EARTH ORBITS; AIR TRAFFIC; INMARSAT SATELLITES; GEOSYNCHRONOUS ORBITS
20080047443 NASA Glenn Research Center, Cleveland, OH, United States
High-Temperature Properties of Piezoelectric Langatate Single Crystals
Sehirlioglu, Alp; Sayir, Ali; Klemenz, Christine; December 02, 2007; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNC07BA13BWBS 984754.02.07.03.16.04
Copyright; Avail.: CASI: A01, Hardcopy
Langasite type crystals belong to non-polar point group of 32 and do not show any phase transformations up to the melting temperature. Langatate (La3Ga(5.5)Ta(0.5)O14) demonstrates piezoelectric activity better than quartz and possesses attractive properties for high temperature sensors, resonators and filter applications. High-quality and colorless langatate crystals were grown by the Czochralski technique. The electromechanical and electrical properties of langatate crystals in different crystallographic directions were characterized at elevated temperature. The piezoelectric coefficient along x-axis was 7 pC/N as measured by a Berlincourt meter for a plate geometry with an aspect ratio of 10:1. The dielectric constant did not exhibit any significant temperature dependence (K33 approx. 21 at 30 C and K33 approx. 23 at 600 C). Loss tangent at 100 kHz remained <0.003 up to 300 C and <0.65 at 600 C. The dielectric properties along the y-axis were similar and its temperature dependence was analogous to the x-axis. Electromechanically, the inactive z-axis exhibited no resonance with K33 approx. 84 at room temperature, decreasing down to approx. 49 at 600 C. Resistivity of these crystals along x-axis decreased from approx. 6x10(exp 11) omega-cm at room temperature, to approx. 1.6x10(exp 6) omega-cm at 600 C.
Author
DIELECTRIC PROPERTIES; TEMPERATURE DEPENDENCE; PIEZOELECTRICITY; PHASE TRANSFORMATIONS; ELECTRICAL RESISTIVITY; SINGLE CRYSTALS; TEMPERATURE SENSORS
20080047444 NASA Glenn Research Center, Cleveland, OH, United States
Collaborative Research on the Ultra High Bypass Ratio Engine Cycle to Reduce Noise, Emissions,and Fuel Consumption
Hughes, Christopher; May 29, 2008; In English; UTIAS-MITACS International Workshop on Aviation and Climate Change May 29-30, 2008, FROM, FROM, FROM; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.18.04
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047444
A pictorial history of NASA development of advanced engine technologies for reducing environmental emissions and increasing performance from the 1970s to present is presented. The goals of the Subsonic Fixed Wing Program portion of the NASA Fundamental Aeronautics Program are addressed, along with the areas of investigation currently being pursued by the Ultra High Bypass Partnership Element of the Subsonic Fixed Wing Program to meet the goals. Ultra High Bypass cycle research collaboration successes with Pratt & Whitney are presented.
Author
BYPASS RATIO; ENGINE NOISE; NOISE REDUCTION; FIXED WINGS; FUEL CONSUMPTION
20080047445 NASA Glenn Research Center, Cleveland, OH, United States
Overview of the Orion Vibroacoustic Test Capability at NASA Glenn Research Center
Hughes, William O.; Hozman, Aron D.; McNelis, Mark E.; Otten, Kim D.; May 07, 2008; In English; Overview of the Orion Vibroacoustic Test Capability at NASA Glenn Research Center, 7 May 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 644423.10.34.03.03.03.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047445
In order to support the environmental test needs for our new Orion and Constellation program, NASA is developing unique world-class test facilities. To optimize this testing of spaceflight hardware while minimizing transportation issues, a one-stop, under one roof test capability is being developed at the Space Power Facility at the NASA Glenn Research Center's Plum Brook Station. This facility will provide the capability to perform the following environmental testing: (1) reverberation acoustic testing, (2) mechanical base-shake sine testing, (3) modal testing, (4) thermal-vacuum testing, and (5) EMI/EMC (electromagnetic interference and compatibility) testing. An overview of this test capability will be provided in this presentation, with special focus on the two new vibroacoustic test facilities currently being designed and built, the Reverberant Acoustic Test Facility (RATF) and the Mechanical Vibration Facility (MVF). Testing of the engineering developmental hardware and qualification hardware of the Orion (Crew Exploration Vehicle) will commence shortly after the facilities are commissioned.
Author
ENVIRONMENTAL TESTS; VIBRATIONAL STRESS; ACOUSTICS; ELECTROMAGNETIC COMPATIBILITY; TEST FACILITIES
20080047446 NASA Glenn Research Center, Cleveland, OH, United States
Cutting Edge Technologies Presentation: An Overview of Developing Sensor Technology Directions and Possible Barriers to New Technology Implementation
Hunter, Gary W.; November 2007; In English; Breath Analysis Summit 2007, 1-3 Nov. 2007, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 444543.01.02.01
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047446
The aerospace industry requires the development of a range of chemical sensor technologies for such applications as leak detection, emission monitoring, fuel leak detection, environmental monitoring, and fire detection. A range of chemical sensors are being developed based on micromachining and microfabrication technology to fabricate microsensors with minimal size, weight, and power consumption; and the use of nanomaterials and structures to develop sensors with improved stability combined with higher sensitivity, However, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. These technologies and technical approaches have direct relevance to breath monitoring for clinical applications. This presentation gives an overview of developing cutting-edge sensor technology and possible barriers to new technology implementation. This includes lessons learned from previous microsensor development, recent work in development of a breath monitoring system, and future directions in the implementation of cutting edge sensor technology.
Author
ENVIRONMENTAL MONITORING; AEROSPACE INDUSTRY; ENERGY CONSUMPTION; LESSONS LEARNED; MICROMACHINING
20080047447 NASA Glenn Research Center, Cleveland, OH, United States
Liquid Acquisition Device Testing with Sub-Cooled Liquid Oxygen
Jurns, John M.; McQuillen, John B.; July 21, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 095240.04.04.01.03
Copyright; Avail.: CASI: A03, Hardcopy
When transferring propellant in space, it is most efficient to transfer single phase liquid from a propellant tank to an engine. In earth s gravity field or under acceleration, propellant transfer is fairly simple. However, in low gravity, withdrawing single-phase fluid becomes a challenge. A variety of propellant management devices (PMD) are used to ensure single-phase flow. One type of PMD, a liquid acquisition device (LAD) takes advantage of capillary flow and surface tension to acquire liquid. Previous experimental test programs conducted at NASA have collected LAD data for a number of cryogenic fluids, including: liquid nitrogen (LN2), liquid oxygen (LOX), liquid hydrogen (LH2), and liquid methane (LCH4). The present work reports on additional testing with sub-cooled LOX as part of NASA s continuing cryogenic LAD development program. Test results extend the range of LOX fluid conditions examined, and provide insight into factors affecting predicting LAD bubble point pressures.
Author
LIQUID OXYGEN; CRYOGENIC FLUIDS; PROPELLANT TRANSFER; MICROGRAVITY; SINGLE-PHASE FLOW; LIQUID HYDROGEN; LIQUID NITROGEN; CAPILLARY FLOW; LIQUID ROCKET PROPELLANTS
20080047448 NASA Goddard Space Flight Center, Greenbelt, MD, United States
LISA Beyond Einstein: From the Big Bang to Black Holes. LISA Technology Development at GSFC
Thorpe, James Ira; July 13, 2008; In English; 37th COSPAR Scientific Assembly, 13-20 Jul. 2008, Montreal, Canada; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNH06CC03B
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047448
This viewgraph presentation reviews the work that has been ongoing at the Goddard Space Flight Center (GSFC) in the development of the technology to be used in the Laser Interferometer Space Antenna (LISA) spacecrafts. The prime focus of LISA technology development efforts at NASA/GSFC has been in LISA interferometry. Specifically efforts have been made in the area of laser frequency noise mitigation. Laser frequency noise is addressed through a combination of stabilization and common-mode rejection. Current plans call for two stages of stabilization, pre-stabilization to a local frequency reference and further stabilization using the constellation as a frequency reference. In order for these techniques to be used simultaneously, the pre-stabilization step must provide an adjustable frequency offset. This presentation reports on a modification to the standard modulation/demodulation technique used to stabilize to optical cavities that generates a frequency-tunable reference from a fixed length cavity. This technique requires no modifications to the cavity itself and only minor modifications to the components. The measured noise performance and dynamic range of the laboratory prototype meet the LISA requirements.
CASI
LASER OUTPUTS; LISA (OBSERVATORY); ASTRONOMICAL INTERFEROMETRY; LASER INTERFEROMETRY; INTERFEROMETRY; FREQUENCY STABILITY
20080047449 NASA Dryden Flight Research Center, Edwards, CA, United States
Preliminary Design of a Ramjet for Integration with Ground-Based Launch Assist
Sayles, Emily L.; November 12, 2008; In English; Minority Students in Science and Technology (MUST) Leadership Symposium, 12-16 Nov. 2008, Phoenix, Az, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047449
This viewgraph presentation reviews the preliminary design of a ramjet for integration with a ground based launch assist. The reasons for the use of ground-based launch assist and the proposed mechanism for a system are reviewed. The use of a Optimal Trajectory by Implicit Simulation (OTIS), to model the flight and comparison with an actual rocket trajectory is given. The OTIS system is reviewed, The benefits of a launch assist system are analyzed concluding that a launch assist can provide supersonic speeds thus allowing ignition of ramjet without an onboard compressor. This means a further reduction in total launch weight. The Ramjet study is reviewed next. This included a review of the ONX simulations, the verification of the ONX results with the use of Holloman Sled experiment data as derived from the Feasibility of Ramjet Engine Test Capability on The Holloman AFB Sled Track. The conclusion was that the ONX system was not sufficient to meet the needs for the modeling required. The GECAT (Graphical Engine Cycle Analysis Tool) is examined. The results of the GECAT simulations was verified with data from Stataltex and D21 flights. The Next steps are: to create a GECAT Model of a launch assist ramjet, to adjust the geometry to produce the desired thrust, and to survey the ramjet's performance over a range of Mach numbers. The assumptions and requirements of a launch assist ramjet are given, and the acceptable flight regimes are reviewed.
CASI
RAMJET ENGINES; SIMULATION; LAUNCH VEHICLES
20080047453 NASA Glenn Research Center, Cleveland, OH, United States
High Temperature Aerogels for Thermal Protection Systems
Hurwitz, Frances I.; Mbah, Godfrey C.; January 27, 2008; In English; 32nd Annual Conference on Composites, Materials and Structures, 27 Jan. - 1 Feb. 2008, Daytona Beach, Fl, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.16.03
Copyright; Avail.: CASI: A03, Hardcopy
High temperature aerogels in the Al2O3-SiO2 system are being investigated as possible constituents for lightweight integrated thermal protection system (TPS) designs for use in supersonic and hypersonic applications. Gels are synthesized from ethoxysilanes and AlCl3.6H2O, using an epoxide catalyst. The influence of Al:Si ratio, solvent, water to metal and water to alcohol ratios on aerogel composition, morphology, surface area, and pore size distribution were examined, and phase transformation on heat treatment characterized. Aerogels have been fabricated which maintain porous, fractal structures after brief exposures to 1000 C. Incorporation of nanofibers, infiltration of aerogels into SiC foams, use of polymers for crosslinking the aerogels, or combinations of these, offer potential for toughening and integration of TPS with composite structure. Woven fabric composites having Al2O3-SiO2 aerogels as a matrix also have been fabricated. Continuing work is focused on reduction in shrinkage and optimization of thermal and physical properties.
Author
ALUMINUM OXIDES; SILICON DIOXIDE; AEROGELS; HIGH TEMPERATURE; THERMAL PROTECTION; THERMODYNAMIC PROPERTIES; FRACTALS; HEAT TREATMENT
20080047456 NASA Glenn Research Center, Cleveland, OH, United States
Lunar Dust Mitigation Technology Development
Hyatt, Mark J.; Deluane, Paul B.; February 11, 2008; In English; 6th Space Technology and Applications International Forum: Space Colonization, 11 Feb. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047456
NASA s plans for implementing the Vision for Space Exploration include returning to the moon as a stepping stone for further exploration of Mars, and beyond. Dust on the lunar surface has a ubiquitous presence which must be explicitly addressed during upcoming human lunar exploration missions. While the operational challenges attributable to dust during the Apollo missions did not prove critical, the comparatively long duration of impending missions presents a different challenge. Near term plans to revisit the moon places a primary emphasis on characterization and mitigation of lunar dust. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it s potentially harmful effects on exploration systems. This paper presents the current perspective and implementation of dust knowledge management and integration, and mitigation technology development activities within NASA s Exploration Technology Development Program. This work is presented within the context of the Constellation Program s Integrated Lunar Dust Management Strategy. The Lunar Dust Mitigation Technology Development project has been implemented within the ETDP. Project scope and plans will be presented, along with a a perspective on lessons learned from Apollo and forensics engineering studies of Apollo hardware. This paper further outlines the scientific basis for lunar dust behavior, it s characteristics and potential effects, and surveys several potential strategies for its control and mitigation both for lunar surface operations and within the working volumes of a lunar outpost.
Author
LUNAR DUST; MAN ENVIRONMENT INTERACTIONS; SPACE EXPLORATION; LUNAR SURFACE; LUNAR SOIL; GRAVITATIONAL EFFECTS; DUST; REGOLITH
20080047457 Cleveland State Univ., Cleveland, OH, United States
Microfabrication of a Segmented-Involute-Foil Regenerator, Testing in a Sunpower Stirling Convertor, and Supporting Modeling and Analysis
Ibrahim, Mounir B.; Tew, Roy C.; Gedeon, David; Wood, Gary; McLean, Jeff; July 28, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS3-03124WBS 138494.04.01.01
Copyright; Avail.: CASI: A03, Hardcopy
Under Phase II of a NASA Research Award contract, a prototype nickel segmented-involute-foil regenerator was microfabricated via LiGA and tested in the NASA/Sunpower oscillating-flow test rig. The resulting figure-of-merit was about twice that of the approx.90% porosity random-fiber material currently used in the small 50-100 W Stirling engines recently manufactured for NASA. That work was reported at the 2007 International Energy Conversion Engineering Conference in St. Louis, was also published as a NASA report, NASA/TM-2007-2149731, and has been more completely described in a recent NASA Contractor Report, NASA/CR-2007-2150062. Under a scaled-back version of the original Phase III plan, a new nickel segmentedinvolute- foil regenerator was microfabricated and has been tested in a Sunpower Frequency-Test-Bed (FTB) Stirling convertor. Testing in the FTB convertor produced about the same efficiency as testing with the original random-fiber regenerator. But the high thermal conductivity of the prototype nickel regenerator was responsible for a significant performance degradation. An efficiency improvement (by a 1.04 factor, according to computer predictions) could have been achieved if the regenerator been made from a low-conductivity material. Also the FTB convertor was not reoptimized to take full advantage of the microfabricated regenerator's low flow resistance; thus the efficiency would likely have been even higher had the FTB been completely reoptimized. This report discusses the regenerator microfabrication process, testing of the regenerator in the Stirling FTB convertor, and the supporting analysis. Results of the pre-test computational fluid dynamics (CFD) modeling of the effects of the regenerator-test-configuration diffusers (located at each end of the regenerator) is included. The report also includes recommendations for accomplishing further development of involute-foil regenerators from a higher-temperature material than nickel.
Author
ENERGY CONVERSION; THERMAL CONDUCTIVITY; STIRLING ENGINES; STIRLING CYCLE; OSCILLATING FLOW; ENERGY TECHNOLOGY; COMPUTATIONAL FLUID DYNAMICS
20080047458 NASA Glenn Research Center, Cleveland, OH, United States
Cold Start of a Radiator Equipped with Titanium-Water Heat Pipes
Jaworske, Donald A.; Sanzi, James L.; Siamidis, John; July 28, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 463169.04.03.05.02
Copyright; Avail.: CASI: A03, Hardcopy
Radiator panels utilizing titanium-water heat pipes are being considered for lunar applications. A traditional sandwich structure is envisioned where heat pipes are embedded between two high thermal conductivity face sheets. The heat pipe evaporators are to be thermally connected to the heat source through one or more manifolds containing coolant. Initial radiator operation on the lunar surface would likely follow a cold soak where the water in the heat pipes is purposely frozen. To achieve heat pipe operation, it will be necessary to thaw the heat pipes. One option is to allow the sunlight impinging on the surface at sunrise to achieve this goal. Testing was conducted in a thermal vacuum chamber to simulate the lunar sunrise and additional modeling was conducted to identify steady-state and transient response. It was found that sunlight impinging on the radiator surface at sunrise was insufficient to solely achieve the goal of thawing the water in the heat pipes. However, starting from a frozen condition was accomplished successfully by applying power to the evaporators. Start up in this fashion was demonstrated without evaporator dryout. Concern is raised over thawing thermosyphons, vertical heat pipes operating in a gravity field, with no wick in the condenser section. This paper presents the results of the simulated cold start study and identifies future work to support radiator panels equipped with titanium-water heat pipes.
Author
EVAPORATORS; HEAT PIPES; TITANIUM; THERMAL CONDUCTIVITY; SANDWICH STRUCTURES; HEAT SOURCES; COOLANTS
20080047459 NASA Glenn Research Center, Cleveland, OH, United States
Characterization and Simulation of Thermoacoustic Instability in a Low Emissions Combustor Prototype
DeLaat, John C.; Paxson, Daniel E.; October 07, 2008; In English; Fundamental Aeronautics Program Annual Meeting, 7-9 Oct. 2008, Atlanta, GA, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.19.04
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047459
Extensive research is being done toward the development of ultra-low-emissions combustors for aircraft gas turbine engines. However, these combustors have an increased susceptibility to thermoacoustic instabilities. This type of instability was recently observed in an advanced, low emissions combustor prototype installed in a NASA Glenn Research Center test stand. The instability produces pressure oscillations that grow with increasing fuel/air ratio, preventing full power operation. The instability behavior makes the combustor a potentially useful test bed for research into active control methods for combustion instability suppression. The instability behavior was characterized by operating the combustor at various pressures, temperatures, and fuel and air flows representative of operation within an aircraft gas turbine engine. Trends in instability behavior vs. operating condition have been identified and documented. A simulation developed at NASA Glenn captures the observed instability behavior. The physics-based simulation includes the relevant physical features of the combustor and test rig, employs a Sectored 1-D approach, includes simplified reaction equations, and provides time-accurate results. A computationally efficient method is used for area transitions, which decreases run times and allows the simulation to be used for parametric studies, including control method investigations. Simulation results show that the simulation exhibits a self-starting, self-sustained combustion instability and also replicates the experimentally observed instability trends vs. operating condition. Future plans are to use the simulation to investigate active control strategies to suppress combustion instabilities and then to experimentally demonstrate active instability suppression with the low emissions combustor prototype, enabling full power, stable operation.
Author
GAS TURBINE ENGINES; PRESSURE OSCILLATIONS; AIR FLOW; COMBUSTION STABILITY; FUEL-AIR RATIO
20080047460 NASA Glenn Research Center, Cleveland, OH, United States
A 1 GHz Oscillator-Type Active Antenna
Jordan, Jennifer L.; Scardelletti, Maximilian; Ponchak, George E.; July 05, 2008; In English; 2008 IEEE International Symposium on Antennas and Propagation, 5-12 Jul. 2008, San Diego, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 645836.02.07.03.03.03.02
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047460
Wireless sensors are desired for monitoring aircraft engines, automotive engines, industrial machinery, and many other applications. The most important requirement of sensors is that they do not interfere with the environment that they are monitoring. Therefore, wireless sensors must be small, which demands a high level of integration. Sensors that modulate an oscillator active antenna have advantages of small size, high level of integration, and lower packaging cost. Several types of oscillator active antennas have been reported. Ip et al. demonstrated a CPW line fed patch antenna with a feedback loop [1]. No degradation in performance was noticed without a ground plane. A GaAs FET was used in an amplifier/oscillator-based active antenna [2]. An oscillator based on a Cree SiC transistor was designed and characterized in [3]. This paper reports the integration of the SiC Clapp oscillator to a slotline loop antenna.
Author
FIELD EFFECT TRANSISTORS; LOOP ANTENNAS; MICROWAVE OSCILLATORS; PATCH ANTENNAS; SLOT ANTENNAS; GALLIUM ARSENIDES
20080047462 NASA Ames Research Center, Moffett Field, CA, United States
LCTR2 Design Study and Aeromechanics Analyses
Acree, Cecil W.; October 07, 2008; In English; Fundamental Aeronautics Program Annual Meeting, 7-9 Oct. 2008, Atlanta, GA, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047462
NASA Heavy Lift Rotorcraft systems Investigation produced the Large Civil Tiltrotor (LCTR) advanced conceptual design in 2005. The goal was to identify research requirements for large rotorcraft. New design, LCTR2, is sized to be representative of regional jets (90 passengers), convenient for technology investigations. Focus for near-term research is a more realistic assessment of technology requirements. Use LCR2 to explore fundamental aeromechanics issues. Here present samples of performance optimization.
Author
ROTARY WING AIRCRAFT; TILT ROTOR AIRCRAFT; FLUID MECHANICS; TECHNOLOGY ASSESSMENT
20080047464 NASA Glenn Research Center, Cleveland, OH, United States
Micromechanics-Based Progressive Failure Analysis of Composite Laminates Using Different Constituent Failure Theories
Moncada, Albert M.; Chattopadhyay, Aditi; Bednarcyk, Brett A.; Arnold, Steven M.; April 07, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNX07AD70AWBS 645846.02.07.03.03.02
Copyright; Avail.: CASI: A03, Hardcopy
Predicting failure in a composite can be done with ply level mechanisms and/or micro level mechanisms. This paper uses the Generalized Method of Cells and High-Fidelity Generalized Method of Cells micromechanics theories, coupled with classical lamination theory, as implemented within NASA's Micromechanics Analysis Code with Generalized Method of Cells. The code is able to implement different failure theories on the level of both the fiber and the matrix constituents within a laminate. A comparison is made among maximum stress, maximum strain, Tsai-Hill, and Tsai-Wu failure theories. To verify the failure theories the Worldwide Failure Exercise (WWFE) experiments have been used. The WWFE is a comprehensive study that covers a wide range of polymer matrix composite laminates. The numerical results indicate good correlation with the experimental results for most of the composite layups, but also point to the need for more accurate resin damage progression models.
Author
POLYMER MATRIX COMPOSITES; FAILURE ANALYSIS; LAMINATES; MICROMECHANICS; STRESS-STRAIN RELATIONSHIPS
20080047465 Akron Univ., Akron, OH, United States
Electrical Resistance as a NDE Technique to Monitor Processing and Damage Accumulation in SiC/SiC Composites
Smith, Craig; Morscher, Gregory N.; Xia, Zhenhai; January 27, 2008; In English; 32nd Annual Conference on Composites, Materials, and Structures, 27 Jan. - 1 Feb. 2008, Daytona Beach, FL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07TA78TNNC06ZA03AWBS 599489.02.07.03.02.02.02
Copyright; Avail.: CASI: A03, Hardcopy
Ceramic matrix composites are suitable for high temperature structural applications such as turbine airfoils and hypersonic thermal protection systems. The employment of these materials in such applications is limited by the ability to process components reliable and to accurately monitor and predict damage evolution that leads to failure under stressed-oxidation conditions. Current nondestructive methods such as ultrasound, x-ray, and thermal imaging are limited in their ability to quantify small scale, transverse, in-plane, matrix cracks developed over long-time creep and fatigue conditions. Electrical resistance of SiC/SiC composites is one technique that shows special promise towards this end. Since both the matrix and the fibers are conductive, changes in matrix or fiber properties should relate to changes in electrical conductivity along the length of a specimen or part. Initial efforts to quantify the electrical resistance of different fiber and different matrix SiC/SiC composites will be presented. Also, the effect of matrix cracking on electrical resistivity for several composite systems will be presented. The implications towards electrical resistance as a technique applied to composite processing, damage detection, and life-modeling will be discussed.
Author
CERAMIC MATRIX COMPOSITES; ELECTRICAL RESISTANCE; SILICON CARBIDES; THERMAL PROTECTION; HYPERSONICS; AIRFOILS; NONDESTRUCTIVE TESTS
20080047466 NASA Glenn Research Center, Cleveland, OH, United States
Reliability and Confidence Interval Analysis of a CMC Turbine Stator Vane
Murthy, Pappu L. N.; Gyekenyesi, John P.; Mital, Subodh K.; March 16, 2008; In English; ICCES08 - International Conference on Computational and Experimental Engineering and Sciences, 16-21 Mar. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 510505.03.03.02.01
Copyright; Avail.: CASI: A03, Hardcopy
High temperature ceramic matrix composites (CMC) are being explored as viable candidate materials for hot section gas turbine components. These advanced composites can potentially lead to reduced weight, enable higher operating temperatures requiring less cooling and thus leading to increased engine efficiencies. However, these materials are brittle and show degradation with time at high operating temperatures due to creep as well as cyclic mechanical and thermal loads. In addition, these materials are heterogeneous in their make-up and various factors affect their properties in a specific design environment. Most of these advanced composites involve two- and three-dimensional fiber architectures and require a complex multi-step high temperature processing. Since there are uncertainties associated with each of these in addition to the variability in the constituent material properties, the observed behavior of composite materials exhibits scatter. Traditional material failure analyses employing a deterministic approach, where failure is assumed to occur when some allowable stress level or equivalent stress is exceeded, are not adequate for brittle material component design. Such phenomenological failure theories are reasonably successful when applied to ductile materials such as metals. Analysis of failure in structural components is governed by the observed scatter in strength, stiffness and loading conditions. In such situations, statistical design approaches must be used. Accounting for these phenomena requires a change in philosophy on the design engineer s part that leads to a reduced focus on the use of safety factors in favor of reliability analyses. The reliability approach demands that the design engineer must tolerate a finite risk of unacceptable performance. This risk of unacceptable performance is identified as a component's probability of failure (or alternatively, component reliability). The primary concern of the engineer is minimizing this risk in an economical manner. The methods to accurately determine the service life of an engine component with associated variability have become increasingly difficult. This results, in part, from the complex missions which are now routinely considered during the design process. These missions include large variations of multi-axial stresses and temperatures experienced by critical engine parts. There is a need for a convenient design tool that can accommodate various loading conditions induced by engine operating environments, and material data with their associated uncertainties to estimate the minimum predicted life of a structural component. A probabilistic composite micromechanics technique in combination with woven composite micromechanics, structural analysis and Fast Probability Integration (FPI) techniques has been used to evaluate the maximum stress and its probabilistic distribution in a CMC turbine stator vane. Furthermore, input variables causing scatter are identified and ranked based upon their sensitivity magnitude. Since the measured data for the ceramic matrix composite properties is very limited, obtaining a probabilistic distribution with their corresponding parameters is difficult. In case of limited data, confidence bounds are essential to quantify the uncertainty associated with the distribution. Usually 90 and 95% confidence intervals are computed for material properties. Failure properties are then computed with the confidence bounds. Best estimates and the confidence bounds on the best estimate of the cumulative probability function for R-S (strength - stress) are plotted. The methodologies and the results from these analyses will be discussed in the presentation.
Author
CERAMIC MATRIX COMPOSITES; RELIABILITY ANALYSIS; GAS TURBINE ENGINES; COMPONENT RELIABILITY; ENGINE PARTS; HIGH TEMPERATURE; COMPOSITE MATERIALS; BRITTLE MATERIALS; FAILURE ANALYSIS; DEGRADATION; STATORS; VANES
20080047467 Akron Univ., Akron, OH, United States
Electrical Resistance of Ceramic Matrix Composites for Damage Detection and Life-Prediction
Smith, Craig; Morscher, Gregory N.; Xia, Zhenhai; January 27, 2008; In English; 32nd International Conference and Exposition on Advanced Ceramic and Composites, 27 Jan. - 1 Feb. 2008, Daytona Beach, Fl, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07TA78TNNC06ZA03AWBS 599489.02.07.03.02.02.02
Copyright; Avail.: CASI: A03, Hardcopy
The electric resistance of woven SiC fiber reinforced SiC matrix composites were measured under tensile loading conditions. The results show that the electrical resistance is closely related to damage and that real-time information about the damage state can be obtained through monitoring of the resistance. Such self-sensing capability provides the possibility of on-board/in-situ damage detection or inspection of a component during "down time". The correlation of damage with appropriate failure mechanism can then be applied to accurate life prediction for high-temperature ceramic matrix composites.
Author
CERAMIC MATRIX COMPOSITES; WOVEN COMPOSITES; LIFE (DURABILITY); FIBER COMPOSITES; ELECTRICAL RESISTANCE; DETECTION
20080047468 Akron Univ., Akron, OH, United States
Monitoring Damage Accumulation in Ceramic Matrix Composites Using Electrical Resistivity
Smith, Craig E.; Morscher, Gregory N.; Xia, Zhenhai H.; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07BA13BNNX07AN56HWBS 599489.02.07.03.02.02.02
Copyright; Avail.: CASI: A02, Hardcopy
The electric resistance of woven SiC fiber reinforced SiC matrix composites were measured under tensile loading conditions. The results show that the electrical resistance is closely related to damage and that real-time information about the damage state can be obtained through monitoring of the resistance. Such self-sensing capability provides the possibility of on-board/in-situ damage detection and accurate life prediction for high-temperature ceramic matrix composites. Woven silicon carbide fiber-reinforced silicon carbide (SiC/SiC) ceramic matrix composites (CMC) possess unique properties such as high thermal conductivity, excellent creep resistance, improved toughness, and good environmental stability (oxidation resistance), making them particularly suitable for hot structure applications. In specific, CMCs could be applied to hot section components of gas turbines [1], aerojet engines [2], thermal protection systems [3], and hot control surfaces [4]. The benefits of implementing these materials include reduced cooling air requirements, lower weight, simpler component design, longer service life, and higher thrust [5]. It has been identified in NASA High Speed Research (HSR) program that the SiC/SiC CMC has the most promise for high temperature, high oxidation applications [6]. One of the critical issues in the successful application of CMCs is on-board or insitu assessment of the damage state and an accurate prediction of the remaining service life of a particular component. This is of great concern, since most CMC components envisioned for aerospace applications will be exposed to harsh environments and play a key role in the vehicle s safety. On-line health monitoring can enable prediction of remaining life; thus resulting in improved safety and reliability of structural components. Monitoring can also allow for appropriate corrections to be made in real time, therefore leading to the prevention of catastrophic failures. Most conventional nondestructive evaluation (NDE) techniques such as ultrasonic C-scan, x-ray, thermography, and eddy current are limited since they require structural components of complex geometry to be taken out of service for a substantial length of time for post-damage inspection and assessment. Furthermore, the typical NDE techniques are useful for identifying large interlaminar flaws, but insensitive to CMC materials flaws developed perpendicular to the surface under tensile creep conditions. There are techniques such as piezoelectric sensor [7,8], and optical fiber [9,10] that could be used for on-line health monitoring of CMC structures. However, these systems involve attaching an external sensor or putting special fibers in CMC composites, which would be problematic at high temperature applications.
Author
WOVEN COMPOSITES; ELECTRICAL RESISTANCE; SILICON CARBIDES; CERAMIC MATRIX COMPOSITES; FIBER COMPOSITES; THERMAL CONDUCTIVITY; THERMAL PROTECTION; DAMAGE ASSESSMENT; HIGH TEMPERATURE
Additions to the NASA Aeronautics and Space Database as of 01/01/2009
20080047662 NASA Johnson Space Center, Houston, TX, United States
Cammp Team
Evertt, Shonn F.; Collins, Michael; Hahn, William; October 03, 2008; In English; BAH Texas 2008 Tech Day, 19 Nov. 2008, San Antonio, TX, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNJ04AA01C
Copyright; Avail.: CASI: A03, Hardcopy
The International Space Station (ISS) Configuration Analysis Modeling and Mass Properties (CAMMP) Team is presenting a demo of certain CAMMP capabilities at a Booz Allen Hamilton conference in San Antonio. The team will be showing pictures of low fidelity, simplified ISS models, but no dimensions or technical data. The presentation will include a brief description of the contract and task, description and picture of the Topology, description of Generic Ground Rules and Constraints (GGR&C), description of Stage Analysis with constraints applied, and wrap up with description of other tasks such as Special Studies, Cable Routing, etc. The models include conceptual Crew Exploration Vehicle (CEV) and Lunar Lander images and animations created for promotional purposes, which are based entirely on public domain conceptual images from public NASA web sites and publicly available magazine articles and are not based on any actual designs, measurements, or 3D models. Conceptual Mars rover and lander are completely conceptual and are not based on any NASA designs or data. The demonstration includes High Fidelity Computer Aided Design (CAD) models of ISS provided by the ISS 3D CAD Team which will be used in a visual display to demonstrate the capabilities of the Teamcenter Visualization software. The demonstration will include 3D views of the CAD models including random measurements that will be taken to demonstrate the measurement tool. A 3D PDF file will be demonstrated of the Blue Book fidelity assembly complete model with no vehicles attached. The 3D zoom and rotation will be displayed as well as random measurements from the measurement tool. The External Configuration Analysis and Tracking Tool (ExCATT) Microsoft Access Database will be demonstrated to show its capabilities to organize and track hardware on ISS. The data included will be part numbers, serial numbers, historical, current, and future locations, of external hardware components on station. It includes dates of all external ISS events and flights and the associated hardware changes for each event. The hardware location information does not always reveal the exact location of the hardware, only the general location. In some cases the location is a module or carrier, in other cases it is a WIF socket, handrail, or attach point. Only small portions of the data will be displayed for demonstration purposes.
Author
INTERNATIONAL SPACE STATION; SPACECRAFT CONFIGURATIONS; THREE DIMENSIONAL MODELS; SPACECREWS; DISPLAY DEVICES; COMPUTER AIDED DESIGN; ROVING VEHICLES; MARS SURFACE
20080047663 NASA Langley Research Center, Hampton, VA, United States
MCNPX Cosmic Ray Shielding Calculations with the NORMAN Phantom Model
James, Michael R.; Durkee, Joe W.; McKinney, Gregg; Singleterry Robert; November 08, 2008; In English; 2008 American Nuclear Society's Winter Meeting: Detecting Radiation in Our Radioactive World Workshop For Educators, 8 Nov. 2008, Reno, NV, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 651549.02.07.06
Copyright; Avail.: CASI: A01, Hardcopy
The United States is planning manned lunar and interplanetary missions in the coming years. Shielding from cosmic rays is a critical aspect of manned spaceflight. These ventures will present exposure issues involving the interplanetary Galactic Cosmic Ray (GCR) environment. GCRs are comprised primarily of protons (approx.84.5%) and alpha-particles (approx.14.7%), while the remainder is comprised of massive, highly energetic nuclei. The National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) has commissioned a joint study with Los Alamos National Laboratory (LANL) to investigate the interaction of the GCR environment with humans using high-fidelity, state-of-the-art computer simulations. The simulations involve shielding and dose calculations in order to assess radiation effects in various organs. The simulations are being conducted using high-resolution voxel-phantom models and the MCNPX[1] Monte Carlo radiation-transport code. Recent advances in MCNPX physics packages now enable simulated transport over 2200 types of ions of widely varying energies in large, intricate geometries. We report here initial results obtained using a GCR spectrum and a NORMAN[3] phantom.
Author
RADIATION EFFECTS; GALACTIC COSMIC RAYS; EXPOSURE; MANNED SPACE FLIGHT; RADIATION TRANSPORT; SHIELDING; ALPHA PARTICLES
20080047667 NASA Glenn Research Center, Cleveland, OH, United States
A Novel Nanoionics-based Switch for Microwave Applications
Nessel, James A.; Lee, Richard Q.; Mueller, Carl H.; Kozicki, Michael N.; Ren, Minghan; Morse, Jacki; June 15, 2008; In English; 2008 International Microwave Symposium, 15-20 Jun. 2008, Atlanta, GA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 698671.01.03.41
Copyright; Avail.: CASI: A01, Hardcopy
This paper reports the development and characterization of a novel switching device for use in microwave systems. The device utilizes a switching mechanism based on nanoionics, in which mobile ions within a solid electrolyte undergo an electrochemical process to form and remove a conductive metallic "bridge" to define the change of state. The nanoionics-based switch has demonstrated an insertion loss of approx.0.5dB, isolation of >30dB, low voltage operation (1V), low power (approx. micro-W) and low energy (approx. nJ) consumption, and excellent linearity up to 6 GHz. The switch requires fewer bias operations (due to non-volatile nature) and has a simple planar geometry allowing for novel device structures and easy integration into microwave power distribution circuits.
Author
SWITCHES; MICROWAVE CIRCUITS; MICROWAVE EQUIPMENT; LOW VOLTAGE; INSERTION LOSS; SOLID ELECTROLYTES
20080047668 NASA Glenn Research Center, Cleveland, OH, United States; Case Western Reserve Univ., Cleveland, OH, United States
New Techniques in Characterization of Ferroelectric Materials
Sehirlioglu, Alp; February 24, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07TA77TWBS 984764.02.07.03.16.04
Copyright; Avail.: CASI: A03, Hardcopy
Two new techniques have been developed to characterize Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) based ferroelectric single crystals: (i) electro-thermal imaging, and (ii) single crystal x-ray diffraction in the transmission mode. (i) Electro-thermal imaging is a remote sensing technique that can detect the polarization direction and poling state of a whole crystal slice. This imaging technique utilizes an IR camera to determine the field induced temperature change and does not require any special or destructive sample preparation. In the resulting images it is possible to distinguish regions of 180 deg domains. This powerful technique can be used remotely during poling to determine the poling state of the crystal to avoid over-poling that can result in inferior properties and/or cracking of the crystals. Electro-thermal imaging produced the first direct observations of polarization rotation. Under bipolar field, the domains near the corners were the first to switch direction. As the field increased above the coercive field, domains at the center part of the crystals switched direction. (ii) X-ray diffraction in the transmission mode has long been used in structure determination of organic crystals and proteins; however, it is not used much to characterize inorganic systems. 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystals were examined by this XRD technique for the first time, and a never-before-seen super-lattice was revealed with a doubling of the unit cell in all three directions, giving a cell volume eight times that of a traditional perovskite unit cell. The significance of the super-lattice peaks increased with poling, indicating a structural contribution to ordering. Lack of such observations by electron diffraction in the transmission electron microscope examinations suggests the presence of a bulk effect.
Author
FERROELECTRIC MATERIALS; SINGLE CRYSTALS; CHARACTERIZATION; X RAY DIFFRACTION; REMOTE SENSING; IMAGING TECHNIQUES
20080047672 NASA Glenn Research Center, Cleveland, OH, United States
Jet Penetration into a Scaled Microfabricated Stirling Cycle Regenerator
Sun, Liyong; Simon, Terrence W.; Mantell, Susan; Ibrahim, Mournir; Gedeon, David; Tew, Roy; July 28, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS3-03124WBS 138494.04.01.01
Copyright; Avail.: CASI: A03, Hardcopy
The cooler and heater adjacent to the regenerator of a Stirling cycle engine have tubes or channels which form jets that pass into the regenerator while diffusing within the matrix. An inactive part of the matrix, beyond the cores of these jets, does not participate fully in the heat transfer between the flow of working fluid and the regenerator matrix material, weakening the regenerator s ability to exchange heat with the working fluid. The objective of the present program is to document this effect on the performance of the regenerator and to develop a model for generalizing the results. However, the small scales of actual Stirling regenerator matrices (on the order of tens of microns) make direct measurements of this effect very difficult. As a result, jet spreading within a regenerator matrix has not been characterized well and is poorly understood. Also, modeling is lacking experimental verification. To address this, a large-scale mockup of thirty times actual scale was constructed and operated under conditions that are dynamically similar to the engine operation. Jet penetration with round jets and slot jets into the microfabricated regenerator geometry are then measured by conventional means. The results are compared with those from a study of spreading of round jets within woven screen regenerator for further documentation of the comparative performance of the microfabricated regenerator geometry.
Author
STIRLING CYCLE; COOLERS; HEAT TRANSFER; REGENERATORS; WORKING FLUIDS
20080047674 NASA Glenn Research Center, Cleveland, OH, United States
Effect of Microstructure on Time Dependent Fatigue Crack Growth Behavior In a P/M Turbine Disk Alloy
Telesman, Ignacy J.; Gabb, T. P.; Bonacuse, P.; Gayda, J.; September 14, 2008; In English; 11th International Symposium Superalloys 2008, 14-18 Sep. 2008, Champion, PA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 698259.02.07.03.04
Copyright; Avail.: CASI: A02, Hardcopy
A study was conducted to determine the processes which govern hold time crack growth behavior in the LSHR disk P/M superalloy. Nineteen different heat treatments of this alloy were evaluated by systematically controlling the cooling rate from the supersolvus solutioning step and applying various single and double step aging treatments. The resulting hold time crack growth rates varied by more than two orders of magnitude. It was shown that the associated stress relaxation behavior for these heat treatments was closely correlated with the crack growth behavior. As stress relaxation increased, the hold time crack growth resistance was also increased. The size of the tertiary gamma' in the general microstructure was found to be the key microstructural variable controlling both the hold time crack growth behavior and stress relaxation. No relationship between the presence of grain boundary M23C6 carbides and hold time crack growth was identified which further brings into question the importance of the grain boundary phases in determining hold time crack growth behavior. The linear elastic fracture mechanics parameter, Kmax, is unable to account for visco-plastic redistribution of the crack tip stress field during hold times and thus is inadequate for correlating time dependent crack growth data. A novel methodology was developed which captures the intrinsic crack driving force and was able to collapse hold time crack growth data onto a single curve.
Author
TIME DEPENDENCE; FATIGUE (MATERIALS); CRACKS; HEAT RESISTANT ALLOYS; FRACTURE STRENGTH; STRESS DISTRIBUTION; POWDER METALLURGY; FRACTURE MECHANICS; MICROSTRUCTURE
20080047675 NASA Glenn Research Center, Cleveland, OH, United States
Kevlar 49/Epoxy COPV Aging Evaluation
Sutter, James K.; Salem, Jonathan L.; Thesken, John C.; Russell, Richard W.; Littell, Justin; Ruggeri, Charles; Leifeste, Mark R.; April 21, 2008; In English; Aging Aircraft 2008, 21-24 Apr. 2008, Phoenix, AZ, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 510505.03.03.02.01
Copyright; Avail.: CASI: A03, Hardcopy
NASA initiated an effort to determine if the aging of Kevlar 49/Epoxy composite overwrapped pressure vessels (COPV) affected their performance. This study briefly reviews the history and certification of composite pressure vessels employed on NASA Orbiters. Tests to evaluate overwrap tensile strength changes compared 30 year old samples from Orbiter vessels to new Kevlar/Epoxy pressure vessel materials. Other tests include transverse compression and thermal analyses (glass transition and moduli). Results from these tests do not indicate a noticeable effect due to aging of the overwrap materials.
Author
KEVLAR (TRADEMARK); COMPOSITE WRAPPING; PRESSURE VESSELS; EPOXY RESINS; AGING (MATERIALS)
20080047676 NASA Glenn Research Center, Cleveland, OH, United States
Enigmatic Moisture Effects on Al2O3 Scale and TBC Adhesion
Smialek, James L.; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.16.02
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047676
Alumina scale adhesion to high temperature alloys is known to be affected primarily by sulfur segregation and reactive element additions. However adherent scales can become partially compromised by excessive strain energy and cyclic cracking. With time, exposure of such scales to moisture can lead to spontaneous interfacial decohesion, occurring while the samples are maintained at ambient conditions. Examples of this Moisture-Induced Delayed Spallation (MIDS) are presented for NiCrAl and single crystal superalloys, becoming more severe with sulfur level and cyclic exposure conditions. Similarly, delayed failure or Desk Top Spallation (DTS) results are reviewed for TBC s, culminating in the water drop failure test. Both phenomena are discussed in terms of moisture effects on bulk alumina and bulk aluminides. A mechanism is proposed based on hydrogen embrittlement and is supported by a cathodic hydrogen charging experiment. Hydroxylation of aluminum from the alloy interface appears to be the relevant basic reaction.
Author
ALUMINUM ALLOYS; ADHESION; SULFUR; REACTIVITY; MOISTURE; SPALLATION; HEAT RESISTANT ALLOYS
20080047678 NASA Glenn Research Center, Cleveland, OH, United States
Large-scale Simulations and Detailed Flow Field Measurements for Turbomachinery Aeroacoustics
VanZante, Dale; March 10, 2008; In English; Graduate Seminar, 10 Mar. 2008, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.18.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047678
The presentation is a review of recent work in highly loaded compressors, turbine aeroacoustics and cooling fan noise. The specific topics are: the importance of correct numerical modeling to capture blade row interactions in the Ultra Efficient Engine Technology Proof-of-Concept Compressor, the attenuation of a detonation pressure wave by an aircraft axial turbine stage, current work on noise sources and acoustic attenuation in turbines, and technology development work on cooling fans for spaceflight applications. The topic areas were related to each other by certain themes such as the advantage of an experimentalist s viewpoint when analyzing numerical simulations and the need to improve analysis methods for very large numerical datasets.
Author
AEROACOUSTICS; TURBOMACHINERY; NOISE REDUCTION; AXIAL FLOW TURBINES; FLOW DISTRIBUTION; ACOUSTIC ATTENUATION; AERODYNAMIC NOISE; COMPRESSORS
20080047679 NASA Glenn Research Center, Cleveland, OH, United States
A Numerical Investigation of Turbine Noise Source Hierarchy and Its Acoustic Transmission Characteristics: Proof-of-Concept Progress
VanZante, Dale; Envia, Edmane; September 23, 2008; In English; Acoustics Technical Working Group Meeting, 23-24 Sep. 2008, Williamsburg, VA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561681.02.08.03.18.02
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047679
A CFD-based simulation of single-stage turbine was done using the TURBO code to assess its viability for determining acoustic transmission through blade rows. Temporal and spectral analysis of the unsteady pressure data from the numerical simulations showed the allowable Tyler-Sofrin modes that are consistent with expectations. This indicated that high-fidelity acoustic transmission calculations are feasible with TURBO.
Author
COMPUTATIONAL FLUID DYNAMICS; ACOUSTIC PROPAGATION; NOISE GENERATORS; SPECTRUM ANALYSIS; SOUND TRANSMISSION
20080047680 NASA Glenn Research Center, Cleveland, OH, United States
Microwave Sensor for Blade Tip Clearance and Structural Health Measurements
Woike, Mark R.; Bencic, Timothy J.; May 05, 2008; In English; 54th International Instrumentation Symposium (ISA), 5-8 May 2008, Pensacola, Fl, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.13.06
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047680
The use of microwave based sensors for the health monitoring of rotating machinery is being explored at the NASA Glenn Research Center. The microwave sensor works on the principle of sending a continuous signal towards a rotating component and measuring the reflected signal. The phase shift of the reflected signal is proportional to the distance between the sensor and the component that is being measured. This type of sensor is beneficial in that it has the ability to operate at extremely high temperatures and is unaffected by contaminants that may be present in the rotating machinery. It is intended to use these probes in the hot sections of turbine engines for closed loop turbine clearance control and structural health measurements. Background on the sensors, an overview of their calibration and preliminary results from using them to make blade tip clearance and health measurements on a large axial vane fan will be presented.
Author
MICROWAVE SENSORS; BLADE TIPS; CONTAMINANTS; HIGH TEMPERATURE; TURBINE ENGINES; PHASE SHIFT
20080047681 NASA Glenn Research Center, Cleveland, OH, United States
Review of Aircraft Engine Fan Noise Reduction
VanZante, Dale; April 02, 2008; In English; Quiet, Efficient Fans for Spaceflight Workshop, 2-34Apr. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 439906.04.01.02.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047681
Aircraft turbofan engines incorporate multiple technologies to enhance performance and durability while reducing noise emissions. Both careful aerodynamic design of the fan and proper installation of the fan into the system are requirements for achieving the performance and acoustic objectives. The design and installation characteristics of high performance aircraft engine fans will be discussed along with some lessons learned that may be applicable to spaceflight fan applications.
Author
NOISE REDUCTION; TURBOFAN ENGINES; AERODYNAMIC NOISE; ENGINE NOISE; FIGHTER AIRCRAFT; AERODYNAMICS
20080047683 NASA Glenn Research Center, Cleveland, OH, United States
A Numerical Investigation of Turbine Noise Source Hierarchy and Its Acoustic Transmission Characteristics
VanZante, Dale; Envia, Edmane; May 08, 2008; In English; Turbine Noise Workshop, 8-9 May 2008, Vancouver, Canada; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 526282.01.03.02.01.09
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047683
Understanding the relative importance of the various turbine noise generation mechanisms and the characteristics of the turbine acoustic transmission loss are essential ingredients in developing robust reduced-order models for predicting the turbine noise signature. A computationally based investigation has been undertaken to help guide the development of a turbine noise prediction capability that does not rely on empiricism. The investigation relies on highly detailed numerical simulations of the unsteady flowfield inside a modern high-pressure turbine (HPT). The simulations are developed using TURBO, which is an unsteady Reynolds-averaged Navier-Stokes (URANS) code capable of multi-stage simulations. The purpose of this study is twofold. First, to determine an estimate of the relative importance of the contributions to the coherent part of the acoustic signature of a turbine from the three potential sources of turbine noise generation, namely, blade-row viscous interaction, potential field interaction, and entropic source associated with the interaction of the blade rows with the temperature nonuniformities caused by the incomplete mixing of the hot fluid and the cooling flow. Second, to develop an understanding of the turbine acoustic transmission characteristics and to assess the applicability of existing empirical and analytical transmission loss models to realistic geometries and flow conditions for modern turbine designs. The investigation so far has concentrated on two simulations: (1) a single-stage HPT and (2) a two-stage HPT and the associated inter-turbine duct/strut segment. The simulations are designed to resolve up to the second harmonic of the blade passing frequency tone in accordance with accepted rules for second order solvers like TURBO. The calculations include blade and vane cooling flows and a radial profile of pressure and temperature at the turbine inlet. The calculation can be modified later to include the combustor pattern factor at the turbine inlet to include that contribution to turbine noise. We shall present preliminary analysis of the results obtained so far in order to assess the validity of such an approach and to seek feedback on improving the approach. This work addresses both Area 1 (Turbine Tone Noise) and Area 5 (Influence of the Turbine on Combustor Noise) topics.
Author
NOISE PREDICTION; ACOUSTIC PROPAGATION; MATHEMATICAL MODELS; NOISE GENERATORS; SOUND TRANSMISSION; FLOW DISTRIBUTION; TURBINE BLADES
Additions to the NASA Aeronautics and Space Database as of 01/02/2009
20080047695 NASA Glenn Research Center, Cleveland, OH, United States
A Numerical Study of Anti-Vortex Film Cooling Designs at High Blowing Ratio
Heidmann, James D.; November 2008; In English; ASME Turbo Expo 2008 Gas Turbine Technical Congress and Exposition, 9-13 Jun. 2008, Berlin, Germany; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.21.02
Report No.(s): NASA/TM-2008-215209; GT2008-50845; E-16482; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047695
A concept for mitigating the adverse effects of jet vorticity and liftoff at high blowing ratios for turbine film cooling flows has been developed and studied at NASA Glenn Research Center. This "anti-vortex" film cooling concept proposes the addition of two branched holes from each primary hole in order to produce a vorticity counter to the detrimental kidney vortices from the main jet. These vortices typically entrain hot freestream gas and are associated with jet separation from the turbine blade surface. The anti-vortex design is unique in that it requires only easily machinable round holes, unlike shaped film cooling holes and other advanced concepts. The anti-vortex film cooling hole concept has been modeled computationally for a single row of 30deg angled holes on a flat surface using the 3D Navier-Stokes solver Glenn-HT. A modification of the anti-vortex concept whereby the branched holes exit adjacent to the main hole has been studied computationally for blowing ratios of 1.0 and 2.0 and at density ratios of 1.0 and 2.0. This modified concept was selected because it has shown the most promise in recent experimental studies. The computational results show that the modified design improves the film cooling effectiveness relative to the round hole baseline and previous anti-vortex cases, in confirmation of the experimental studies.
Author
VORTICITY; TURBINE BLADES; BLOWING; FILM COOLING; HIGH TEMPERATURE GASES; FREE FLOW; HOLES (MECHANICS)
20080047696 NASA Dryden Flight Research Center, Edwards, CA, United States
Ikhana: A NASA UAS Supporting Long Duration Earth Science Missions
Cobleigh, Brent R.; March 2007; In English; Original contains color illustrations
Contract(s)/Grant(s): WU 769134.03.02.02.05
Report No.(s): NASA/TM-2007-214614; H-2688; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047696
The NASA Ikhana unmanned aerial vehicle (UAV) is a General Atomics Aeronautical Systems Inc. (San Diego, California) MQ-9 Predator-B modified to support the conduct of Earth science missions for the NASA Science Mission Directorate and, through partnerships, other government agencies and universities. It can carry over 2000 lb of experiment payloads in the avionics bay and external pods and is capable of mission durations in excess of 24 hours at altitudes above 40,000 ft. The aircraft is remotely piloted from a mobile ground control station (GCS) that is designed to be deployable by air, land, or sea. On-board support capabilities include an instrumentation system and an Airborne Research Test System (ARTS). The Ikhana project will complete GCS development, science support systems integration, external pod integration and flight clearance, and operations crew training in early 2007. A large-area remote sensing mission is currently scheduled for Summer 2007.
Author
PILOTLESS AIRCRAFT; EARTH SCIENCES; SUPPORT SYSTEMS; GROUND BASED CONTROL; AVIONICS; FLIGHT OPERATIONS; REMOTE SENSING
20080047713 NASA Ames Research Center, Moffett Field, CA, United States
Performance of Advanced Heavy-Lift, High-Speed Rotorcraft Configurations
Johnson, Wayne; Yeo, Hyeonsoo; Acree, C. W., Jr.; October 15, 2007; In English; AHS International Forum on Rotorcraft Multidisciplinary Technology, 15-17 Oct. 2007, Seoul, Korea, Republic of; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047713
The aerodynamic performance of rotorcraft designed for heavy-lift and high-speed cruise is examined. Configurations considered include the tiltrotor, the compound helicopter, and the lift-offset rotor. Design conditions are hover and 250-350 knot cruise, at 5k/ISA+20oC (civil) or 4k/95oF (military); with cruise conditions at 4000 or 30,000 ft. The performance was calculated using the comprehensive analysis CAMRAD II, emphasizing rotor optimization and performance, including wing-rotor interference. Aircraft performance was calculated using estimates of the aircraft drag and auxiliary propulsion efficiency. The performance metric is total power, in terms of equivalent aircraft lift-to-drag ratio L/D = WV/P for cruise, and figure of merit for hover.
Author
AERODYNAMIC CONFIGURATIONS; ROTARY WING AIRCRAFT; LIFT DRAG RATIO; TILT ROTOR AIRCRAFT; COMPOUND HELICOPTERS
20080047714 NASA Ames Research Center, Moffett Field, CA, United States
Requirements for Next Generation Comprehensive Analysis of Rotorcraft
Johnson, Wayne; Data, Anubhav; January 23, 2008; In English; American Helicopter Society Specialists' Conference on Aeromechanics, 23-25 Jan. 2008, San Francisco, CA, United States
Copyright; Avail.: CASI: A02, Hardcopy
The unique demands of rotorcraft aeromechanics analysis have led to the development of software tools that are described as comprehensive analyses. The next generation of rotorcraft comprehensive analyses will be driven and enabled by the tremendous capabilities of high performance computing, particularly modular and scaleable software executed on multiple cores. Development of a comprehensive analysis based on high performance computing both demands and permits a new analysis architecture. This paper describes a vision of the requirements for this next generation of comprehensive analyses of rotorcraft. The requirements are described and substantiated for what must be included and justification provided for what should be excluded. With this guide, a path to the next generation code can be found.
Author
ROTARY WING AIRCRAFT; SOFTWARE DEVELOPMENT TOOLS; COMPUTER PROGRAMS; MODULARITY; FLUID MECHANICS
20080047715 NASA Ames Research Center, Moffett Field, CA, United States
An Assessment of the State-of-the-art in Multidisciplinary Aeromechanical Analyses
Datta, Anubhav; Johnson, Wayne; January 23, 2008; In English; American Helicopter Society Specialists' Conference on Aeromechanics, 23-25 Jan. 2008, San Francisco, CA, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047715
This paper presents a survey of the current state-of-the-art in multidisciplinary aeromechanical analyses which integrate advanced Computational Structural Dynamics (CSD) and Computational Fluid Dynamics (CFD) methods. The application areas to be surveyed include fixed wing aircraft, turbomachinery, and rotary wing aircraft. The objective of the authors in the present paper, together with a companion paper on requirements, is to lay out a path for a High Performance Computing (HPC) based next generation comprehensive rotorcraft analysis. From this survey of the key technologies in other application areas it is possible to identify the critical technology gaps that stem from unique rotorcraft requirements.
Author
ROTARY WING AIRCRAFT; COMPUTATIONAL FLUID DYNAMICS; DYNAMIC STRUCTURAL ANALYSIS; DYNAMIC RESPONSE; FIXED WINGS; AIRCRAFT CONFIGURATIONS
20080047716 NASA Ames Research Center, Moffett Field, CA, United States
Influence of Lift Offset on Rotorcraft Performance
Johnson, Wayne; January 23, 2008; In English; American Helicopter Society Specialists' Conference on Aeromechanics, 23-25 Jan. 2008, San Francisco, CA, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047716
The influence of lift offset on the performance of several rotorcraft configurations is explored. A lift-offset rotor, or advancing blade concept, is a hingeless rotor that can attain good efficiency at high speed, by operating with more lift on the advancing side than on the retreating side of the rotor disk. The calculated performance capability of modern-technology coaxial rotors utilizing a lift offset is examined, including rotor performance optimized for hover and high-speed cruise. The ideal induced power loss of coaxial rotors in hover and twin rotors in forward flight is presented. The aerodynamic modeling requirements for performance calculations are evaluated, including wake and drag models for the high speed flight condition. The influence of configuration on the performance of rotorcraft with lift-offset rotors is explored, considering tandem and side-by-side rotorcraft as well as wing-rotor lift share.
Author
AERODYNAMIC CHARACTERISTICS; HORIZONTAL FLIGHT; ROTOR LIFT; ROTARY WING AIRCRAFT; WAKES
20080047724 NASA Johnson Space Center, Houston, TX, United States
RFID in Space: Exploring the Feasibility and Performance of Gen 2 Tags as a Means of Tracking Equipment, Supplies, and Consumable Products in Cargo Transport Bags onboard a Space Vehicle or Habitat
Jones, Erick C.; Richards, Casey; Herstein, Kelli; Franca, Rodrigo; Yagoda, Evan L.; Vasquez, Reuben; October 31, 2008; In English; RFID in Space - Gen 2 Tag Study, 10 Oct. 2008, Houston, TX, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A08, Hardcopy
Current inventory management techniques for consumables and supplies aboard space vehicles are burdensome and time consuming. Inventory of food, clothing, and supplies are taken periodically by manually scanning the barcodes on each item. The inaccuracy of reading barcodes and the excessive amount of time it takes for the astronauts to perform this function would be better spent doing scientific experiments. Therefore, there is a need for an alternative method of inventory control by NASA astronauts. Radio Frequency Identification (RFID) is an automatic data capture technology that has potential to create a more effective and user-friendly inventory management system (IMS). In this paper we introduce a Design for Six Sigma Research (DFSS-R) methodology that allows for reliability testing of RFID systems. The research methodology uses a modified sequential design of experiments process to test and evaluate the quality of commercially available RFID technology. The results from the experimentation are compared to the requirements provided by NASA to evaluate the feasibility of using passive Generation 2 RFID technology to improve inventory control aboard crew exploration vehicles.
Author
INVENTORY CONTROLS; INVENTORY MANAGEMENT; BAGS; CARGO; CONSUMABLES (SPACECRAFT); HABITATS; RADIO FREQUENCIES; INVENTORIES
20080047727 NASA Glenn Research Center, Cleveland, OH, United States
Failure Mechanisms and Life Prediction of Thermal and Environmental Barrier Coatings under Thermal Gradients
Zju, Dongming; Ghosn, Louis J.; Miller, Robert A.; January 30, 2008; In English; 32nd International Conference on Advanced Ceramics and Composites, 27 Jan. - 1 Feb. 2008, Daytona Beach, Fl, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.16.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047727
Ceramic thermal and environmental barrier coatings (TEBCs) will play an increasingly important role in gas turbine engines because of their ability to further raise engine temperatures. However, the issue of coating durability is of major concern under high-heat-flux conditions. In particular, the accelerated coating delamination crack growth under the engine high heat-flux conditions is not well understood. In this paper, a laser heat flux technique is used to investigate the coating delamination crack propagation under realistic temperature-stress gradients and thermal cyclic conditions. The coating delamination mechanisms are investigated under various thermal loading conditions, and are correlated with coating dynamic fatigue, sintering and interfacial adhesion test results. A coating life prediction framework may be realized by examining the crack initiation and propagation driving forces for coating failure under high-heat-flux test conditions.
Author
THERMAL CONTROL COATINGS; CERAMIC COATINGS; FAILURE ANALYSIS; CRACK PROPAGATION; STRESS DISTRIBUTION; GAS TURBINE ENGINES; FATIGUE TESTS
20080047728 NASA Glenn Research Center, Cleveland, OH, United States
The Lattice and Thermal Radiation Conductivity of Thermal Barrier Coatings
Zhu, Dongming; Spuckler, Charles M.; January 27, 2008; In English; 32nd International Conference on Advanced Ceramics and Composites, 27 Jan. - 1 Feb. 2008, Daytona Beach, Fl, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.16.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047728
The lattice and radiation conductivity of thermal barrier coatings was evaluated using a laser heat flux approach. A diffusion model has been established to correlate the apparent thermal conductivity of the coating to the lattice and radiation conductivity. The radiation conductivity component can be expressed as a function of temperature and the scattering and absorption properties of the coating material. High temperature scattering and absorption of the coating systems can also be derived based on the testing results using the modeling approach. The model prediction is found to have good agreement with experimental observations.
Author
THERMAL CONTROL COATINGS; HIGH TEMPERATURE; THERMAL RADIATION; THERMAL CONDUCTIVITY; LASERS; HEAT FLUX
20080047729 NASA Glenn Research Center, Cleveland, OH, United States
Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions (Invited paper)
Zhu, Dongming; Miller, Robert A.; April 27, 2008; In English; 35th International Conference On Metallurgical Coatings And Thin Films (ICMCTF 2008), 27 Apr. 2 May 2008, San Diego, CA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 877888.02.07.03.05.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047729
Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.
Author
THERMAL CONTROL COATINGS; CORROSION RESISTANCE; IMPACT RESISTANCE; TRANSITION METALS; THERMAL CONDUCTIVITY; HIGH TEMPERATURE; THERMAL STABILITY
20080047730 LibertyWorks, United States
Rolls-Royce Low Noise Highly Variable Cycle Nozzle for Next Generation Supersonic Aircraft
Sokhey, Jack S.; Kube-McDowell, Matthew; October 07, 2008; In English; Fundamental Aeronautics Annual Meeting, 7-9 Oct. 2008, Atlanta, GA, United States; Original contains color illustrations
Contract(s)/Grant(s): NNL08AA29CWBS 984754.02.07.03.17.04
Copyright; Avail.: CASI: A03, Hardcopy
An overview of the work performed by Rolls-Royce under contract NNL08AA29C is presented. The work includes computational fluid dynamic (CFD) analysis for, and design of, a highly variable cycle exhaust model for the Supersonic project (NRA NN06ZEA001N). The CFD analysis shows that the latest design improvements to the clam shell doors have increased flow through the ejector over that achieved with previous designs.
Author
COMPUTATIONAL FLUID DYNAMICS; LOW NOISE; EJECTORS; SUPERSONIC AIRCRAFT
20080047731 NASA Glenn Research Center, Cleveland, OH, United States
Development of a Temperature Sensor for Jet Engine and Space Mission Applications
Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik; Culley, Dennis; May 12, 2008; In English; HiTEC 2008 High Temperature Electronics Conference/International Microelectronics and Packaging society (IMAPS), 12-15 May 2008, Albuquerque, NM, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07BWBS 561581.02.08.03.17.03
Copyright; Avail.: CASI: A01, Hardcopy
Electronics for Distributed Turbine Engine Control and Space Exploration Missions are expected to encounter extreme temperatures and wide thermal swings. In particular, circuits deployed in a jet engine compartment are likely to be exposed to temperatures well exceeding 150 C. To meet this requirement, efforts exist at the NASA Glenn Research Center (GRC), in support of the Fundamental Aeronautics Program/Subsonic Fixed Wing Project, to develop temperature sensors geared for use in high temperature environments. The sensor and associated circuitry need to be located in the engine compartment under distributed control architecture to simplify system design, improve reliability, and ease signal multiplexing. Several circuits were designed using commercial-off-the-shelf as well as newly-developed components to perform temperature sensing at high temperatures. The temperature-sensing circuits will be described along with the results pertaining to their performance under extreme temperature.
Author
ACTIVE CONTROL; ENGINE CONTROL; HIGH TEMPERATURE ENVIRONMENTS; TEMPERATURE SENSORS; CONTROL SYSTEMS DESIGN; MULTIPLEXING
20080047732 NASA Glenn Research Center, Cleveland, OH, United States
The NASA Evolutionary Xenon Thruster (NEXT): NASA's Next Step for U.S. Deep Space Propulsion
Schmidt, George R.; Patterson, Michael J.; Benson, Scott W.; September 29, 2008; In English; IAC 2008 59th International Astronautical Congress, 29 Sep. - 3 Oct. 2008, Glasgow, Scotland, United Kingdom; Original contains color illustrations
Contract(s)/Grant(s): WBS 562282.01.03.02.02.15
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047732
NASA s Evolutionary Xenon Thruster (NEXT) project is developing next generation ion propulsion technologies to enhance the performance and lower the costs of future NASA space science missions. This is being accomplished by producing Engineering Model (EM) and Prototype Model (PM) components, validating these via qualification-level and integrated system testing, and preparing the transition of NEXT technologies to flight system development. The project is currently completing one of the final milestones of the effort, that is operation of an integrated NEXT Ion Propulsion System (IPS) in a simulated space environment. This test will advance the NEXT system to a NASA Technology Readiness Level (TRL) of 6 (i.e., operation of a prototypical system in a representative environment), and will confirm its readiness for flight. Besides its promise for upcoming NASA science missions, NEXT may have excellent potential for future commercial and international spacecraft applications.
Author
ION PROPULSION; ION ENGINES; SYSTEMS ENGINEERING; COST REDUCTION; SYSTEMS INTEGRATION
20080047737 NASA Glenn Research Center, Cleveland, OH, United States
Review of Full-Scale Docking Seal Testing Capabilities
Dunlap, Patrick H., Jr.; Penney, Nicholas; Wasowski, Janice L.; Daniels, Christopher C.; Steinetz, Bruce M.; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford,CT, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 644423.06.31.04.01.03.22
Copyright; Avail.: CASI: A03, Hardcopy
NASA is developing a new docking system to support future space exploration missions to low-Earth orbit, the Moon, and Mars. This mechanism, called the Low Impact Docking System (LIDS), is designed to connect pressurized space vehicles and structures including the Crew Exploration Vehicle, International Space Station, and lunar lander. NASA Glenn Research Center (GRC) is playing a key role in developing the main interface seal for this new docking system. These seals will be approximately 147 cm (58 in.) in diameter. To evaluate the performance of the seals under simulated operating conditions, NASA GRC is developing two new test rigs: a non-actuated version that will be used to measure seal leak rates and an actuated test rig that will be able to measure both seal leak rates and loads. Both test rigs will be able to evaluate the seals under seal-on-seal or seal-on-plate configurations at temperatures from -50 to 50 C (-58 to 122 F) under operational and pre-flight checkout pressure gradients in both aligned and misaligned conditions.
Author
DOCKING; SPACE EXPLORATION; LOW EARTH ORBITS; SPACECREWS; INTERNATIONAL SPACE STATION; PRESSURE GRADIENTS
20080047738 NASA Glenn Research Center, Cleveland, OH, United States
A Resonant Damping Study Using Piezoelectric Materials
Min, J. B.; Duffy, K. P.; Choi, B. B.; Morrison, C. R.; Jansen, R. H.; Provenza, A. J.; April 07, 2008; In English; 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials, 7-10 Apr. 2008, Schaumburg, IL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.03
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047738
Excessive vibration of turbomachinery blades causes high cycle fatigue (HCF) problems requiring damping treatments to mitigate vibration levels. Based on the technical challenges and requirements learned from previous turbomachinery blade research, a feasibility study of resonant damping control using shunted piezoelectric patches with passive and active control techniques has been conducted on cantilever beam specimens. Test results for the passive damping circuit show that the optimum resistive shunt circuit reduces the third bending resonant vibration by almost 50%, and the optimum inductive circuit reduces the vibration by 90%. In a separate test, active control reduced vibration by approximately 98%.
Author
VIBRATION DAMPING; PIEZOELECTRICITY; RESONANT VIBRATION; TURBOMACHINERY; BENDING VIBRATION; ACTIVE CONTROL
20080047739 Ohio Aerospace Inst., Cleveland, OH, United States
Design Guidelines for In-Plane Mechanical Properties of SiC Fiber-Reinforced Melt-Infiltrated SiC Composites
Morscher, Gregory N.; Pujar, Vijay V.; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06ZA03AWBS 599489.02.07.03.02.02.02
Copyright; Avail.: CASI: A03, Hardcopy
In-plane tensile stress-strain, tensile creep, and after-creep retained tensile properties of melt-infiltrated SiC-SiC composites reinforced with different fiber types were evaluated with an emphasis on obtaining simple or first-order microstructural design guidelines for these in-plane mechanical properties. Using the mini-matrix approach to model stress-strain behavior and the results of this study, three basic general design criteria for stress and strain limits are formulated, namely a design stress limit, a design total strain limit, and an after-creep design retained strength limit. It is shown that these criteria can be useful for designing components for high temperature applications.
Author
TENSILE PROPERTIES; STRESS-STRAIN RELATIONSHIPS; MECHANICAL PROPERTIES; CREEP STRENGTH; FIBER COMPOSITES
20080047741 NASA Glenn Research Center, Cleveland, OH, United States
Design of a Model Execution Framework: Repetitive Object-Oriented Simulation Environment (ROSE)
Gray, Justin S.; Briggs, Jeffery L.; November 2008; In English; 44th Joint Propulsion Conference and Exhibit, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.03.09.02
Report No.(s): NASA/TM-2008-215299; AIAA Paper-2008-4860; E-16568; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047741
The ROSE framework was designed to facilitate complex system analyses. It completely divorces the model execution process from the model itself. By doing so ROSE frees the modeler to develop a library of standard modeling processes such as Design of Experiments, optimizers, parameter studies, and sensitivity studies which can then be applied to any of their available models. The ROSE framework accomplishes this by means of a well defined API and object structure. Both the API and object structure are presented here with enough detail to implement ROSE in any object-oriented language or modeling tool.
Author
COMPLEX SYSTEMS; SENSITIVITY; OBJECT-ORIENTED PROGRAMMING; EXPERIMENT DESIGN
20080047742 NASA Glenn Research Center, Cleveland, OH, United States
Performance of Subscale Docking Seals Under Simulated Temperature Conditions
Smith, Ian M.; Daniels, Christopher C.; October 2008; In English; 44th Joint Propulsion Conference and Exhibit, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC08CA35CWBS 644423.06.31.04.01.03.22
Report No.(s): NASA/TM-2008-215428; AIAA Paper-2008-4713; E-16605; Copyright; Avail.: CASI: A03, Hardcopy
A universal docking system is being developed by the National Aeronautics and Space Administration (NASA) to support future space exploration missions to low Earth orbit (LEO), to the moon, and to Mars. The candidate docking seals for the system are a composite design consisting of elastomer seal bulbs molded into the front and rear sides of a metal ring. The test specimens were subscale seals with two different elastomer cross-sections and a 12-in. outside diameter. The seal assemblies were mated in elastomer seal-on-metal plate and elastomer seal-on-elastomer seal configurations. The seals were manufactured from S0383-70 silicone elastomer compound. Nominal and off-nominal joint configurations were examined. Both the compression load required to mate the seals and the leak rate observed were recorded while the assemblies were subjected to representative docking system operating temperatures of -58, 73, and 122 F (-50, 23, and 50 C). Both the loads required to fully compress the seals and their leak rates were directly proportional to the test temperature.
Author
DOCKING; LEAKAGE; NASA SPACE PROGRAMS; SPACE EXPLORATION; LOW EARTH ORBITS; COMPRESSION LOADS
20080047743 NASA Glenn Research Center, Cleveland, OH, United States
Adhesion of Silicone Elastomer Seals for NASA's Crew Exploration Vehicle
deGroh, Henry C., III; Miller, Sharon K. R.; Smith, Ian M.; Daniels, Christopher C.; Steinetz, Bruce M; October 2008; In English; 44th Joint Propulsion Conference and Exhibit, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 644423.06.31.04.01.03.22
Report No.(s): NASA/TM-2008-215433; E-16598; Copyright; Avail.: CASI: A03, Hardcopy
Silicone rubber seals are being considered for a number of interfaces on NASA's Crew Exploration Vehicle (CEV). Some of these joints include the docking system, hatches, and heat shield-to-back shell interface. A large diameter molded silicone seal is being developed for the Low Impact Docking System (LIDS) that forms an effective seal between the CEV and International Space Station (ISS) and other future Constellation Program spacecraft. Seals between the heat shield and back shell prevent high temperature reentry gases from leaking into the interface. Silicone rubber seals being considered for these locations have inherent adhesive tendencies that would result in excessive forces required to separate the joints if left unchecked. This paper summarizes adhesion assessments for both as-received and adhesion-mitigated seals for the docking system and the heat shield interface location. Three silicone elastomers were examined: Parker Hannifin S0899-50 and S0383-70 compounds, and Esterline ELA-SA-401 compound. For the docking system application various levels of exposure to atomic oxygen (AO) were evaluated. Moderate AO treatments did not lower the adhesive properties of S0899-50 sufficiently. However, AO pretreatments of approximately 10(exp 20) atoms/sq cm did lower the adhesion of S0383-70 and ELA-SA-401 to acceptable levels. For the heat shield-to-back shell interface application, a fabric covering was also considered. Molding Nomex fabric into the heat shield pressure seal appreciably reduced seal adhesion for the heat shield-to-back shell interface application.
Author
ADHESION; SILICONE RUBBER; ELASTOMERS; DOCKING; HEAT SHIELDING; INTERNATIONAL SPACE STATION; CREW EXPLORATION VEHICLE; HIGH TEMPERATURE GASES
20080047748 NASA Goddard Space Flight Center, Greenbelt, MD, United States
WMAP - A Portrait of the Early Universe
Wollack, Edward J.; November 21, 2008; In English; International Conference on Recent Advances in Microwave Theory and Application, 21-24 Nov. 2008, Jaipur, India
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047748
A host of astrophysical observations suggest that early Universe was incredibly hot, dense, and homogeneous. A powerful probe of this time is provided by the relic radiation which we refer to today as the Cosmic Microwave Background (CMB). Images produced from this light contain the earliest glimpse of the Universe after the 'Big Bang' and the signature of the evolution of its contents. By exploiting these clues, constraints on the age, mass density, and geometry of the early Universe can be derived. A brief history of the evolution of the microwave radiometer systems and map making approaches used in advancing these aspects our understanding of cosmological will be reviewed. In addition, an overview of the results from NASA's Wilkinson Microwave Anisotropy (WMAP) will be presented.
Author
MICROWAVE ANISOTROPY PROBE; GALACTIC EVOLUTION; ASTRONOMICAL MAPS
20080047750 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The Effects of Low Dose-Rate Ionizing Radiation on the Shapes of Transients in the LM124 Operational Amplifier
Buchner, Stephen; McMorrow, Dale; Roche, Nicholas; Dusseau, Laurent; Pease, Ron L.; [2008]; In English; Original contains black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
Shapes of single event transients (SETs) in a linear bipolar circuit (LM124) change with exposure to total ionizing dose (TID) radiation. SETs shape changes are a direct consequence of TID-induced degradation of bipolar transistor gain. A reduction in transistor gain causes a reduction in the drive current of the current sources in the circuit, and it is the lower drive current that most affects the shapes of large amplitude SETs.
Author
IONIZING RADIATION; TRAVELING IONOSPHERIC DISTURBANCES; EXPOSURE; DEGRADATION; BIPOLAR TRANSISTORS
Additions to the NASA Aeronautics and Space Database as of 01/05/2009
20080047927 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Effects of the 2006 El Nino on Tropospheric Ozone and Carbon Monoxide: Implications for Dynamics and Biomass Burning
Chandra, S.; Ziemke, J. R.; Duncan, B. N.; Diehl, t. L.; [2008]; In English; Original contains black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
We have studied the effects of the 2006 El Nino on tropospheric O3 and CO at tropical and sub-tropical latitudes measured from the OMI and MLS instruments on the Aura satellite. The 2006 El Nino-induced drought allowed forest fires set to clear land to burn out of control during October and November in the Indonesian region. The effects of these fires are clearly seen in the enhancement of GO concentration measured from the MLS instrument. We have used a global model of atmospheric chemistry and transport (GMI CTM) to quantify the relative irrrportance of biomass burning and large scale transport: in producing observed changes in tropospheric O3 and CO . The model results show that during October and November both biomass burning and meteorological changes contributed almost equally to the observed increase in tropospheric O3 in the Indonesian region. The biomass component was 4-6 DU but it was limited to the Indonesian region where the fires were most intense, The dynamical component was 4-8 DU but it covered a much larger area in the Indian Ocean extending from South East Asia in the north to western Australia in the south. By December 2006, the effect of biomass taming was reduced to zero and the obsemed changes in tropospheric O3 were mostly due to dynamical effects. The model results show an increase of 2-3% in the global burden of tropospheric ozone. In comparison, the global burdean of CO increased by 8-12%.
Author
EL NINO; BIOMASS BURNING; TROPICAL REGIONS; DROUGHT; OZONE; ATMOSPHERIC CHEMISTRY; ATMOSPHERIC MODELS; TROPOSPHERE
20080047929 Ohio Aerospace Inst., Cleveland, OH, United States
Characterization of Brazed Joints of C-C Composite to Cu-clad-Molybdenum
Singh, M.; Asthana, R.; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07TB09TWBS 877868.02.07.03.05.03
Copyright; Avail.: CASI: A03, Hardcopy
Carbon-carbon composites with either pitch+CVI matrix or resin-derived matrix were joined to copper-clad molybdenum using two active braze alloys, Cusil-ABA (1.75% Ti) and Ticusil (4.5% Ti). The brazed joints revealed good interfacial bonding, preferential precipitation of Ti at the composite/braze interface, and a tendency toward de-lamination in resin-derived C-C composite due to its low inter-laminar shear strength. Extensive braze penetration of the inter-fiber channels in the pitch+CVI C-C composites was observed. The relatively low brazing temperatures (<950 C) precluded melting of the clad layer and restricted the redistribution of alloying elements but led to metallurgically sound composite joints. The Knoop microhardness (HK) distribution across the joint interfaces revealed sharp gradients at the Cu-clad-Mo/braze interface and higher hardness in Ticusil (approx.85-250 HK) than in Cusil-ABA (approx.50-150 HK). These C-C/Cu-clad-Mo joints with relatively low thermal resistance may be promising for thermal management applications.
Author
CARBON-CARBON COMPOSITES; MOLYBDENUM; TEMPERATURE CONTROL; COPPER; SCANNING ELECTRON MICROSCOPY; MICROHARDNESS
20080047939 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Eta Carinae across the 2003.5 Minimum: Analysis in the Visible and Near Infrared Spectral Region
Nielsen, K. E.; Kober, G. Vieira; Weis, K.; Gull, T.; Stahl, O.; Bomans, D. J.; [2008]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
We present analysis of the visible through near infrared spectrum of eta Car and its ejecta obtained during the 'eta Car Campaign with the Ultraviolet Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT)'. This is a part of larger effort to present a complete eta Car spectrum, and extends the previously presented analyses with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) in the UV (1240-3159 A) to 10,430 A. The spectrum in the mid and near UV is characterized by the ejecta absorption. At longer wavelengths, stellar wind features from the central source and narrow emission lines from the Weigelt condensations dominate the spectrum. However, narrow absorption lines from the circumstellar shells are present. This paper provides a description of the spectrum between 3060 and 10,430 A, including line identifications of the ejecta absorption spectrum, the emission spectrum from the Weigelt condensations and the P-Cygni stellar wind features. The high spectral resolving power of VLT/UVES enables equivalent width measurements of atomic and molecular absorption lines for elements with no transitions at the shorter wavelengths. However, the ground based seeing and contributions of nebular scattered radiation prevent direct comparison of measured equivalent widths in the VLT/UVES and HST/STIS spectra. Fortunately, HST/STIS and VLT/UVES have a small overlap in wavelength coverage which allows us to compare and adjust for the difference in scattered radiation entering the instruments apertures. This paper provide a complete online VLT/UVES spectrum with line identifications and a spectral comparison between HST/STIS and VLT/UVES between 3060 and 3160 A.
Author
MASSIVE STARS; BLUE STARS; EJECTA; INFRARED SPECTRA; ABSORPTION SPECTRA; EMISSION SPECTRA
20080047940 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The Detectability of Exo-Earths and Super-Earths via Resonant Signatures in Exozodiacal Clouds
Stark, Christopher C.; Kuchner, Marc; [2008]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Directly imaging extrasolar terrestrial planets necessarily means contending with the astrophysical noise of exozodiacal dust and the resonant structures created by these planets in exozodiacal clouds. Using a custom tailored hybrid symplectic integrator we have constructed 120 models of resonant structures created by exo-Earths and super-Earths on circular orbits interacting with collisionless steady-state dust clouds around a Sun-like star. Our models include enough particles to overcome the limitations of previous simulations that were often dominated by a handful of long-lived particles, allowing us to quantitatively study the contrast of the resulting ring structures. We found that in the case of a planet on a circular orbit, for a given star and dust source distribution, the morphology and contrast of the resonant structures depend on only two parameters: planet mass and (square root)ap/Beta, where ap is the planet's semi-major axis and Beta is the ratio of radiation pressure force to gravitational force on a grain. We constructed multiple-grain-size models of 25,000 particles each and showed that in a collisionless cloud, a Dohnanyi crushing law yields a resonant ring whose optical depth is dominated by the largest grains in the distribution, not the smallest. We used these models to estimate the mass of the lowest-mass planet that can be detected through observations of a resonant ring for a variety of assumptions about the dust cloud and the planet's orbit. Our simulations suggest that planets with mass as small as a few times Mars' mass may produce detectable signatures in debris disks at ap greater than or approximately equal to 10 AU.
Author
EXTRASOLAR PLANETS; PLANET DETECTION; ZODIACAL DUST; PLANETARY MASS
20080047941 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Correlations of the IR Luminosity and Eddington Ratio with a Hard X-ray Selected Sample of AGN
Mushotzy, Richard F.; Winter, Lisa M.; McIntosh, Daniel H.; Tueller, Jack; [2008]; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NAG5-13102
Copyright; Avail.: CASI: A03, Hardcopy
We use the SWIFT Burst Alert Telescope (BAT) sample of hard x-ray selected active galactic nuclei (AGN) with a median redshift of 0.03 and the 2MASS J and K band photometry to examine the correlation of hard x-ray emission to Eddington ratio as well as the relationship of the J and K band nuclear luminosity to the hard x-ray luminosity. The BAT sample is almost unbiased by the effects of obscuration and thus offers the first large unbiased sample for the examination of correlations between different wavelength bands. We find that the near-IR nuclear J and K band luminosity is related to the BAT (14 - 195 keV) luminosity over a factor of 10(exp 3) in luminosity (L(sub IR) approx.equals L(sub BAT)(sup 1.25) and thus is unlikely to be due to dust. We also find that the Eddington ratio is proportional to the x-ray luminosity. This new result should be a strong constraint on models of the formation of the broad band continuum.
Author
NEAR INFRARED RADIATION; SEYFERT GALAXIES; SWIFT OBSERVATORY; ACTIVE GALACTIC NUCLEI; SUPERHIGH FREQUENCIES; LUMINOSITY; RED SHIFT
Additions to the NASA Aeronautics and Space Database as of 01/06/2009
20080047953 Akron Univ., Akron, OH, United States; NASA Glenn Research Center, Cleveland, OH, United States
Evaluating Dimethyldiethoxysilane for use in Polyurethane Crosslinked Silica Aerogels
Randall, Jason P.; Meador, Mary Ann B.; Jana, Sadhan C.; August 17, 2008; In English; 236th American Chemical Society Meeting, 17-21 Aug. 2008, Philadelphia, PA, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Silica aerogels are highly porous materials which exhibit exceptionally low density and thermal conductivity. Their "pearl necklace" nanostructure, however, is inherently weak; most silica aerogels are brittle and fragile. The strength of aerogels can be improved by employing an additional crosslinking step using isocyanates. In this work, dimethyldiethoxysilane (DMDES) is evaluated for use in the silane backbone of polyurethane crosslinked aerogels. Approximately half of the resulting aerogels exhibited a core/shell morphology of hard crosslinked aerogel surrounding a softer, uncrosslinked center. Solid state NMR and scanning electron microscopy results indicate the DMDES incorporated itself as a conformal coating around the outside of the secondary silica particles, in much the same manner as isocyanate crosslinking. Response surface curves were generated from compression data, indicating levels of reinforcement comparable to that in previous literature, despite the core/shell morphology.
Author
AEROGELS; SILICON DIOXIDE; SCANNING ELECTRON MICROSCOPY; ISOCYANATES; BRITTLENESS; CROSSLINKING; NANOSTRUCTURE (CHARACTERISTICS); THERMAL CONDUCTIVITY; POROUS MATERIALS
20080047958 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Gravitational Radiation Characteristics of Nonspinning Black-Hole Binaries
Kelly, B. J.; Baker, J. G.; Boggs, W. D.; Centrella, J. M.; vanMeter, J. R.; McWilliams, S. T.; [2008]; In English; Original contains color illustrations
Contract(s)/Grant(s): 05-BEFS-05-0044; 06-BEFS06-19
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080047958
We present a detailed descriptive analysis of the gravitational radiation from binary mergers of non-spinning black holes, based on numerical relativity simulations of systems varying from equal-mass to a 6:1 mass ratio. Our analysis covers amplitude and phase characteristics of the radiation, suggesting a unified picture of the waveforms' dominant features in terms of an implicit rotating source, applying uniformly to the full wavetrain, from inspiral through ringdown. We construct a model of the late-stage frequency evolution that fits the l = m modes, and identify late-time relationships between waveform frequency and amplitude. These relationships allow us to construct a predictive model for the late-time waveforms, an alternative to the common practice of modelling by a sum of quasinormal mode overtones. We demonstrate an application of this in a new effective-one-body-based analytic waveform model.
Author
BLACK HOLES (ASTRONOMY); BINARY STARS; GRAVITATIONAL WAVES; ROTATION; MATHEMATICAL MODELS; MASS RATIOS; HARMONICS
20080047960 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The Long-term Middle Atmospheric Influence of Very Large Solar Proton Events
Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Randall, Cora E.; Fleming, Eric L.; Frith, Stacey M.; [2008]; In English; Original contains black and white illustrations
Copyright; Avail.: CASI: A04, Hardcopy
Long-term variations in ozone have been caused by both natural and humankind related processes. The humankind or anthropogenic influence on ozone originates from the chlorofluorocarbons and halons (chlorine and bromine) and has led to international regulations greatly limiting the release of these substances. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the long-term (> few months) influences of solar proton events from 1963 through 2004 on stratospheric ozone and temperature. There were extremely large solar proton events in 1972, 1989,2000,2001, and 2003. These events caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen-containing compounds, which led to the polar ozone destruction. The nitrogen-containing compounds, called odd nitrogen, lasted much longer than the hydrogen-containing compounds and led to long-lived stratospheric impacts. An extremely active period for these events occurred in the five-year period, 2000- 2004, and caused increases in odd nitrogen which lasted for several months after individual events. Associated stratospheric ozone decreases of >lo% were calculated to last for up to five months past the largest events. However, the computed total column ozone and stratospheric temperature changes connected with the solar events were not found to be statistically significant. Thus, solar proton events do not likely contribute significantly to measured total column ozone fluctuations and stratospheric temperature changes.
Author
SOLAR ACTIVITY EFFECTS; ATMOSPHERIC MODELS; CHARGED PARTICLES; CLIMATE MODELS; EARTH MAGNETOSPHERE; HYDROGEN COMPOUNDS; MAN ENVIRONMENT INTERACTIONS; NITROGEN COMPOUNDS; SOLAR PROTONS
20080047961 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The Analysis of Image Segmentation Hierarchies with a Graph-based Knowledge Discovery System
Tilton, James C.; Cooke, diane J.; Ketkar, Nikhil; Aksoy, Selim; [2008]; In English; Original contains black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Currently available pixel-based analysis techniques do not effectively extract the information content from the increasingly available high spatial resolution remotely sensed imagery data. A general consensus is that object-based image analysis (OBIA) is required to effectively analyze this type of data. OBIA is usually a two-stage process; image segmentation followed by an analysis of the segmented objects. We are exploring an approach to OBIA in which hierarchical image segmentations provided by the Recursive Hierarchical Segmentation (RHSEG) software developed at NASA GSFC are analyzed by the Subdue graph-based knowledge discovery system developed by a team at Washington State University. In this paper we discuss out initial approach to representing the RHSEG-produced hierarchical image segmentations in a graphical form understandable by Subdue, and provide results on real and simulated data. We also discuss planned improvements designed to more effectively and completely convey the hierarchical segmentation information to Subdue and to improve processing efficiency.
Author
IMAGE ANALYSIS; DATA MINING; COMPUTER PROGRAMS; GRAPHS (CHARTS)
20080047962 Science Systems and Applications, Inc., Lanham, MD, United States
Comparison of GPCP Monthly and Daily Precipitation Estimates with High-Latitude Gauge Observations
Bolvin, David T.; Adler, Robert G.; Nelkin, Eric J.; Poutiainen, Jani; [2008]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
It is very important to know how much rain and snow falls around the world for uses that range from crop forecasting to disaster response, drought monitoring to flood forecasting, and weather analysis to climate research. Precipitation is usually measured with rain gauges, but rain gauges don t exist in areas that are sparsely populated, which tends to be a good portion of the globe. To overcome this, meteorologists use satellite data to estimate global precipitation. However, it is difficult to estimate rain and especially snow in cold climates using most current satellites. The satellite sensors are often "confused" by a snowy or frozen surface and therefore cannot distinguish precipitation. One commonly used satellite-based precipitation data set, the Global Precipitation Climatology Project (GPCP) data, overcomes this frozen-surface problem through the innovative use of two sources of satellite data, the Television Infrared Observation Satellite Operational Vertical Sounder (TOVS) and the Atmospheric Infrared Sounder (AIRS). Though the GPCP estimates are generally considered a very reliable source of precipitation, it has been difficult to assess the quality of these estimates in cold climates due to the lack of gauges. Recently, the Finnish Meteorological Institute (FMI) has provided a 12-year span of high-quality daily rain gauge observations, covering all of Finland, that can be used to compare with the GPCP data to determine how well the satellites estimate cold-climate precipitation. Comparison of the monthly GPCP satellite-based estimates and the FMI gauge observations shows remarkably good agreement, with the GPCP estimates being 6% lower in the amount of precipitation than the FMI observations. Furthermore, the month-to-month correlation between the GPCP and FMI is very high at 0.95 (1.0 is perfect). The daily GPCP estimates replicate the FMI daily occurrences of precipitation with a correlation of 0.55 in the summer and 0.45 in the winter. The winter result indicates the GPCP estimates have skill in "seeing" snowfall, which is the most challenging situation. Thus, the GPCP data set successfully overcomes a current limitation in satellite meteorology, namely the estimation of cold-climate precipitation. The success of the GPCP data set bodes well for future missions, whose instrumentation is specifically designed to give even more information for addressing cold-climate precipitation.
Author
ATMOSPHERIC SOUNDING; CLIMATOLOGY; FORECASTING; SNOW; PRECIPITATION (METEOROLOGY); METEOROLOGY; METEOROLOGICAL SATELLITES; INFRARED INSTRUMENTS; FLOODS
20080047969 Rose-Hulman Inst. of Tech., Terre Haute, IN, United States
Simulink Model of the Ares I Upper Stage Main Propulsion System
Burchett, Bradley T.; August 18, 2008; In English; AIAA Modeling and Simulation Technologies Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains black and white illustrations
Contract(s)/Grant(s): NNM07AA02A
Copyright; Avail.: CASI: A03, Hardcopy
A numerical model of the Ares I upper stage main propulsion system is formulated based on first principles. Equation's are written as non-linear ordinary differential equations. The GASP fortran code is used to compute thermophysical properties of the working fluids. Complicated algebraic constraints are numerically solved. The model is implemented in Simulink and provides a rudimentary simulation of the time history of important pressures and temperatures during re-pressurization, boost and upper stage firing. The model is validated against an existing reliable code, and typical results are shown.
Author
ARES 1 UPPER STAGE; SPACECRAFT DESIGN; SPACECRAFT PROPULSION; PROPULSION SYSTEM CONFIGURATIONS; COMPUTER PROGRAMS; COMPUTERIZED SIMULATION; FAULT DETECTION; ALGORITHMS; NUMERICAL ANALYSIS
Additions to the NASA Aeronautics and Space Database as of 01/07/2009
20080047981 NASA, Washington, DC, United States
NASA Tech Briefs, October 2008
October 2008; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Topics covered include: Control Architecture for Robotic Agent Command and Sensing; Algorithm for Wavefront Sensing Using an Extended Scene; CO2 Sensors Based on Nanocrystalline SnO2 Doped with CuO; Improved Airborne System for Sensing Wildfires; VHF Wide-Band, Dual-Polarization Microstrip-Patch Antenna; Onboard Data Processor for Change-Detection Radar Imaging; Using LDPC Code Constraints to Aid Recovery of Symbol Timing; System for Measuring Flexing of a Large Spaceborne Structure; Integrated Formation Optical Communication and Estimation System; Making Superconducting Welds between Superconducting Wires; Method for Thermal Spraying of Coatings Using Resonant-Pulsed Combustion; Coating Reduces Ice Adhesion; Hybrid Multifoil Aerogel Thermal Insulation; SHINE Virtual Machine Model for In-flight Updates of Critical Mission Software; Mars Image Collection Mosaic Builder; Providing Internet Access to High-Resolution Mars Images; Providing Internet Access to High-Resolution Lunar Images; Expressions Module for the Satellite Orbit Analysis Program Virtual Satellite; Small-Body Extensions for the Satellite Orbit Analysis Program (SOAP); Scripting Module for the Satellite Orbit Analysis Program (SOAP); XML-Based SHINE Knowledge Base Interchange Language; Core Technical Capability Laboratory Management System; MRO SOW Daily Script; Tool for Inspecting Alignment of Twinaxial Connectors; An ATP System for Deep-Space Optical Communication; Polar Traverse Rover Instrument; Expert System Control of Plant Growth in an Enclosed Space; Detecting Phycocyanin-Pigmented Microbes in Reflected Light; DMAC and NMP as Electrolyte Additives for Li-Ion Cells; Mass Spectrometer Containing Multiple Fixed Collectors; Waveguide Harmonic Generator for the SIM; Whispering Gallery Mode Resonator with Orthogonally Reconfigurable Filter Function; Stable Calibration of Raman Lidar Water-Vapor Measurements; Bimaterial Thermal Compensators for WGM Resonators; Root Source Analysis/ValuStream[Trade Mark] - A Methodology for Identifying and Managing Risks; Ensemble: an Architecture for Mission-Operations Software; Object Recognition Using Feature-and Color-Based Methods; On-Orbit Multi-Field Wavefront Control with a Kalman Filter; and The Interplanetary Overlay Networking Protocol Accelerator.
Author
AEROGELS; BINARY SYSTEMS (MATERIALS); CHANGE DETECTION; DOPED CRYSTALS; EXPERT SYSTEMS; IMAGING TECHNIQUES; KALMAN FILTERS; MICROORGANISMS; NASA PROGRAMS
20080047982 California Inst. of Tech., Pasadena, CA, United States
Polar Traverse Rover Instrument
Karlsson, Henrik; Radulescu, Andreea; Behar, Alberto; Pegors, Mika; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English
Report No.(s): NPO-45463; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3290
A Polar Traverse Rover (PTR) is a device designed to determine the role of Antarctica in the global climate system by determining typical paths of continental air that passes the South Pole, and by obtaining insight into the relationship between events at the Antarctic and the meteorology of sub-polar altitudes. The PTR is a 2-m-diameter ball in which an Iridium modem, with an integrated global positioning system (GPS) receiver and a commercial lithium battery pack, is suspended. The modem is attached to an aluminum plate and is surrounded by shock-absorbing plastic for protection. This core is attached to the interior walls of the shell by strings on three axis points. The unit s total weight is 10 kg, and it returns data regarding location, altitude, ground velocity, and vertical velocity. The PTR traverses the terrain solely through being blown around by the wind. The unit is much lighter than its predecessor, the Tumbleweed, and requires less wind to put it in motion and to sustain motion. The system is autonomous, requiring minimal monitoring, and enables long-range, unmanned scientific surface surveys in harsh environments.
Author
ROVING VEHICLES; AUTONOMY; POLAR METEOROLOGY; GLOBAL POSITIONING SYSTEM; ANTARCTIC REGIONS; POSITION (LOCATION); MODEMS
20080047983 NASA Kennedy Space Center, Cocoa Beach, FL, United States
Core Technical Capability Laboratory Management System
Shaykhian, Linda; Dugger, Curtis; Griffin, Laurie; NASA Tech Briefs, October 2008; October 2008; pp. 19-2; In English
Report No.(s): KSC-13051; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3283
The Core Technical Capability Lab - oratory Management System (CTCLMS) consists of dynamically generated Web pages used to access a database containing detailed CTC lab data with the software hosted on a server that allows users to have remote access.
Derived from text
MANAGEMENT SYSTEMS; INFORMATION SYSTEMS; RESOURCE ALLOCATION; LOGISTICS
20080047984 California Inst. of Tech., Pasadena, CA, United States
MRO SOW Daily Script
Fisher, Forest E.; Khanampornpan, Teerapat; Gladden, Roy E.; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English
Report No.(s): NPO-45439; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3284
The MRO SOW daily script (wherein "MRO" signifies "Mars Reconnaissance Orbiter" and "SOW" signifies "sequence systems engineer of the week") is a computer program that automates portions of the MRO daily SOW procedure, which includes checking file-system sizes and automated sequence processor (ASP) log files. The MRO SOW daily script effects clear reporting of (1) the status of, and requirements imposed on, the file system and (2) the ASP log files.
Author
COMPUTER PROGRAMS; DATA PROCESSING; AUTOMATIC CONTROL
20080047985 California Inst. of Tech., Pasadena, CA, United States
XML-Based SHINE Knowledge Base Interchange Language
James, Mark; Mackey, Ryan; Tikidjian, Raffi; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-44546; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3274
The SHINE Knowledge Base Interchange Language software has been designed to more efficiently send new knowledge bases to spacecraft that have been embedded with the Spacecraft Health Inference Engine (SHINE) tool. The intention of the behavioral model is to capture most of the information generally associated with a spacecraft functional model, while specifically addressing the needs of execution within SHINE and Livingstone. As such, it has some constructs that are based on one or the other.
Derived from text
KNOWLEDGE BASED SYSTEMS; DATA SYSTEMS; DATA PROCESSING; ARTIFICIAL INTELLIGENCE; DOCUMENT MARKUP LANGUAGES
20080047986 California Inst. of Tech., Pasadena, CA, United States
Stable Calibration of Raman Lidar Water-Vapor Measurements
Leblanc, Thierry; McDermid, Iain S.; NASA Tech Briefs, October 2008; October 2008; pp. 27-2; In English
Report No.(s): NPO-45955; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3302
A method has been devised to ensure stable, long-term calibration of Raman lidar measurements that are used to determine the altitude-dependent mixing ratio of water vapor in the upper troposphere and lower stratosphere. Because the lidar measurements yield a quantity proportional to the mixing ratio, rather than the mixing ratio itself, calibration is necessary to obtain the factor of proportionality. The present method involves the use of calibration data from two sources: (1) absolute calibration data from in situ radiosonde measurements made during occasional campaigns and (2) partial calibration data obtained by use, on a regular schedule, of a lamp that emits in a known spectrum determined in laboratory calibration measurements. In this method, data from the first radiosonde campaign are used to calculate a campaign-averaged absolute lidar calibration factor (t(sub 1)) and the corresponding campaign-averaged ration (L(sub 1)) between lamp irradiances at the water-vapor and nitrogen wavelengths. Depending on the scenario considered, this ratio can be assumed to be either constant over a long time (L=L(sub 1)) or drifting slowly with time. The absolutely calibrated water-vapor mixing ratio (q) obtained from the ith routine off-campaign lidar measurement is given by q(sub 1)=P(sub 1)/t(sub 1)=LP(sub 1)/P(sup prime)(sub 1) where P(sub 1) is water-vapor/nitrogen measurement signal ration, t(sub 1) is the unknown and unneeded overall efficiency ratio of the lidar receiver during the ith routine off-campaign measurement run, and P(sup prime)(sub 1) is the water-vapor/nitrogen signal ratio obtained during the lamp run associated with the ith routine off-campaign measurement run. If L is assumed constant, then the lidar calibration is routinely obtained without the need for new radiosonde data. In this case, one uses L=L(sub 1) = P(sup prime)(sub 1)/t(sub 1), where P(sub 1)(sup prime) is the water-vapor/nitrogen signal ratio obtained during the lamp run associated with the first radiosonde campaign. If L is assumed to drift slowly, then it is necessary to postpone calculation of a(sub 1) until after a second radiosonde campaign. In this case, one obtains a new value, L(sub 2), from the second radiosonde campaign, and for the ith routine off-campaign measurement run, one uses an intermediate value of L obtained by simple linear time interpolation between L(sub 1) and L(sub 2).
Author
OPTICAL RADAR; RADIOSONDES; CALIBRATING; WATER VAPOR; RADAR MEASUREMENT
20080047987 Bowling Green State Univ., OH, United States
Detecting Phycocynanin-Pigmented Microbes in Reflected Light
Vincent, Robert K.; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English; Original contains color illustrations
Report No.(s): LEW-18202-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3291
A recently invented method of measuring concentrations of phycocynanin-pigmented algae and bacteria in water is based on measurement of the spectrum of reflected sunlight. When present in sufficiently high concentrations, phycocynanin-pigmented microorganisms can be hazardous to the health of humans who use, and of animals that depend on, an affected body of water. The present method is intended to satisfy a need for a rapid, convenient means of detecting hazardous concentrations of phycocynanin-pigmented microorganisms. Rapid detection will speed up the issuance of public health warnings and performance of corrective actions. The method involves the measurement of light reflected from a body of water in at least two, but preferably five wavelength bands. In one version of the method, the five wavelength bands are bands 1, 3, 4, 5, and 7 of the Thematic Mapper (TM) multispectral imaging instrument aboard the Landsat-7 satellite (see table). In principle, other wavelength bands indicative of phycocynanin could be used alternatively or in addition to these five. Moreover, although the method was originally intended specifically for processing Landsat- 7 TM data, it is equally applicable to processing of data from other satellite-borne instruments or from airborne, hand-held, buoy-mounted, tower-mounted, or otherwise mounted instruments that measure radiances of light reflected from water in the wavelength bands of interest.
Author
IMAGING TECHNIQUES; DETECTION; RADIANCE; MICROORGANISMS; BACTERIA; ALGAE; THEMATIC MAPPERS (LANDSAT); SATELLITE-BORNE INSTRUMENTS; PUBLIC HEALTH
20080047988 United Space Alliance, Houston, TX, United States
Tool for Inspecting Alignment of Twinaxial Connectors
Smith, Christopher R.; NASA Tech Briefs, October 2008; October 2008; pp. 21-2; In English; Original contains color illustrations
Report No.(s): MSC-23757; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3287
A proposed tool would be used to inspect alignments of mating twinaxial-connector assemblies on interconnecting wiring harnesses. More specifically, the tool would be used to inspect the alignment of each contact pin of each connector on one assembly with the corresponding socket in the corresponding connector on the other assembly. It is necessary to inspect the alignment because if mating of the assemblies is attempted when any pin/socket pair is misaligned beyond tolerance, the connection will not be completed and the dielectric material in the socket will be damaged (see Figure 1). Although the basic principle of the tool is applicable to almost any type of mating connector assemblies, the specific geometry of the tool must match the pin-and-socket geometry of the specific mating assemblies to be inspected. In the original application for which the tool was conceived, each of the mating assemblies contains eight twinaxial connectors; the pin diameter is 0.014 in. (.0.35 mm), and the maximum allowable pin/socket misalignment is 0.007 in. (.0.18 mm). Incomplete connections can result in loss of flight data within the functional path to the space shuttle crew cockpit displays. The tool (see Figure 2) would consist mainly of a transparent disk with alignment clocking tabs that can be fitted onto either connector assembly. Sets of circles or equivalent reference markings are affixed to the face of the tool, located at the desired positions of the mating contact pairs. An inspector would simply fit the tool onto a connector assembly, engaging the clocking tabs until the tool fits tightly. The inspector would then align one set of circles positioning a line of sight perpendicular to one contact within the connector assembly. Mis alignments would be evidenced by the tip of a pin contact straying past the inner edge of the circle. Socket contact misalignments would be evidenced by a crescent-shaped portion of the white dielectric appearing within the circle. The tool could include a variable magnifier plus an illuminator that could be configured so as not to cast shadows.
Author
CONNECTORS; ALIGNMENT; JOINTS (JUNCTIONS); PINS; MISALIGNMENT; HARNESSES; DIELECTRICS; TABS (CONTROL SURFACES); WIRING
20080047989 California Inst. of Tech., Pasadena, CA, United States
Object Recognition using Feature- and Color-Based Methods
Duong, Tuan; Duong, Vu; Stubberud, Allen; NASA Tech Briefs, October 2008; October 2008; pp. 32-3; In English; Original contains color illustrations
Report No.(s): NPO-41370; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/content/view/3308/34/
An improved adaptive method of processing image data in an artificial neural network has been developed to enable automated, real-time recognition of possibly moving objects under changing (including suddenly changing) conditions of illumination and perspective. The method involves a combination of two prior object-recognition methods one based on adaptive detection of shape features and one based on adaptive color segmentation to enable recognition in situations in which either prior method by itself may be inadequate. The chosen prior feature-based method is known as adaptive principal-component analysis (APCA); the chosen prior color-based method is known as adaptive color segmentation (ACOSE). These methods are made to interact with each other in a closed-loop system to obtain an optimal solution of the object-recognition problem in a dynamic environment. One of the results of the interaction is to increase, beyond what would otherwise be possible, the accuracy of the determination of a region of interest (containing an object that one seeks to recognize) within an image. Another result is to provide a minimized adaptive step that can be used to update the results obtained by the two component methods when changes of color and apparent shape occur. The net effect is to enable the neural network to update its recognition output and improve its recognition capability via an adaptive learning sequence. In principle, the improved method could readily be implemented in integrated circuitry to make a compact, low-power, real-time object-recognition system. It has been proposed to demonstrate the feasibility of such a system by integrating a 256-by-256 active-pixel sensor with APCA, ACOSE, and neural processing circuitry on a single chip. It has been estimated that such a system on a chip would have a volume no larger than a few cubic centimeters, could operate at a rate as high as 1,000 frames per second, and would consume in the order of milliwatts of power.
Author
PATTERN RECOGNITION; IMAGE PROCESSING; SHAPES; COLOR; NEURAL NETS; ARTIFICIAL INTELLIGENCE
20080047990 California Inst. of Tech., Pasadena, CA, United States
On-Orbit Multi-Field Wavefront Control with a Kalman Filter
Lou, John; Sigrist, Norbert; Basinger, Scott; Redding, David; NASA Tech Briefs, October 2008; October 2008; pp. 3; In English
Report No.(s): NPO-45793; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3313
A document describes a multi-field wavefront control (WFC) procedure for the James Webb Space Telescope (JWST) on-orbit optical telescope element (OTE) fine-phasing using wavefront measurements at the NIRCam pupil. The control is applied to JWST primary mirror (PM) segments and secondary mirror (SM) simultaneously with a carefully selected ordering. Through computer simulations, the multi-field WFC procedure shows that it can reduce the initial system wavefront error (WFE), as caused by random initial system misalignments within the JWST fine-phasing error budget, from a few dozen micrometers to below 50 nm across the entire NIRCam Field of View, and the WFC procedure is also computationally stable as the Monte-Carlo simulations indicate. With the incorporation of a Kalman Filter (KF) as an optical state estimator into the WFC process, the robustness of the JWST OTE alignment process can be further improved. In the presence of some large optical misalignments, the Kalman state estimator can provide a reasonable estimate of the optical state, especially for those degrees of freedom that have a significant impact on the system WFE. The state estimate allows for a few corrections to the optical state to push the system towards its nominal state, and the result is that a large part of the WFE can be eliminated in this step. When the multi-field WFC procedure is applied after Kalman state estimate and correction, the stability of fine-phasing control is much more certain. Kalman Filter has been successfully applied to diverse applications as a robust and optimal state estimator. In the context of space-based optical system alignment based on wavefront measurements, a KF state estimator can combine all available wavefront measurements, past and present, as well as measurement and actuation error statistics to generate a Maximum-Likelihood optimal state estimator. The strength and flexibility of the KF algorithm make it attractive for use in real-time optical system alignment when WFC alone cannot effectively align the system.
Author
JAMES WEBB SPACE TELESCOPE; OPTICAL EQUIPMENT; CONTROL SYSTEMS DESIGN; KALMAN FILTERS; AEROSPACE ENGINEERING
20080047991 California Inst. of Tech., Pasadena, CA, United States
System for Measuring Flexing of a Large Spaceborne Structure
Scharf, Daniel; Kuhnert, Andreas; Kovalik, Joseph; Hadaegh, Fred; Shaddock, Daniel; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-45076; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3266
An optoelectronic metrology system is used for determining the attitude and flexing of a large spaceborne radar antenna or similar structure. The measurements are needed for accurate pointing of the antenna and correction and control of the phase of the radar signal wavefront. The system includes a dual-field-of-view star tracker; a laser ranging unit (LRU) and a position-sensitive-detector (PSD)-based camera mounted on an optical bench; and fiducial targets at various locations on the structure. The fiducial targets are illuminated in sequence by laser light coupled via optical fibers. The LRU and the PSD provide measurements of the position of each fiducial target in a reference frame attached to the optical bench. During routine operation, the star tracker utilizes one field of view and functions conventionally to determine the orientation of the optical bench. During operation in a calibration mode, the star tracker also utilizes its second field of view, which includes stars that are imaged alongside some of the fiducial targets in the PSD; in this mode, the PSD measurements are traceable to star measurements.
Author
OPTOELECTRONIC DEVICES; METROLOGY; FLEXING; RADAR ANTENNAS; LARGE SPACE STRUCTURES
20080047992 California Inst. of Tech., Pasadena, CA, United States
Integrated Formation Optical Communication and Estimation System
Scharf, Daniel; Kuhnert, Andreas; Kovalik, Joseph; Hadaegh, Fred; Shaddock, Daniel; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-44558; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3269
An architecture has been designed that integrates formation estimation methodologies, precision formation sensing, and high-bandwidth formation communication into a robust, strap-on system that meets knowledge and communication requirements for the majority of planned, precision formation missions. Specifically, the integrated system supports (a) sub-millimeter metrology, (b) multiple greater than 10 Mbps communication channels over a large, 10 deg field-of-view (FOV), and (c) generalized formation estimation methodologies. The sensing sub-system consists of several absolute, metrology gauges with up to 0.1 mm precision that use amplitude-modulated lasers and a LISA-heritage phase meter. Since amplitude modulation is used, inexpensive and robust diode lasers may be used instead of complex, frequency-stabilized lasers such as for nanometer-level metrology. The metrology subsystem laser transceivers consist of a laser diode, collecting optics, and an avalanche photo diode (APD) for detecting incoming laser signals. The APD is necessary since received power is small due to the large (for optical applications) FOV. The phase meter determines the phase of the incoming amplitude modulations as measured by the APD. This phase is equivalent to time-of-flight and, therefore, distance. By placing three laser transceivers on each spacecraft, 18 clock-offset-corrupted distances are calculated. These measurements are communicated and averaged to obtain nine correct distances between the transceivers. From these correct distances, the range and bearing between spacecraft and their relative attitude are determined. Next, communication is integrated on the laser carrier through spectral separation. Metrology amplitude modulations are limited to the 45-50 MHz band, leaving 0-45 MHz for communication. Through careful design of coding scheme, error correction, and filters, six independent 10 Mbps receive channels are possible. Hence, a spacecraft can simultaneously broadcast at 10 Mbps and listen to six other spacecraft. The integrated sensing and communication architecture has been developed, as have formation estimation methodologies that allow the sensing topology to reconfigure as spacecraft maneuver. A bench-top implementation of the integrated sensing and communication architecture is in progress. The final, multiple sensing/communication systems will be tied together via formation estimation algorithms that are also undergoing further development.
Author
OPTICAL COMMUNICATION; METROLOGY
20080047993 California Inst. of Tech., Pasadena, CA, United States
Expressions Module for the Satellite Orbit Analysis Program
Edmonds, Karina; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-45052; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3279
The Expressions Module is a software module that has been incorporated into the Satellite Orbit Analysis Program (SOAP). The module includes an expressions- parser submodule built on top of an analytical system, enabling the user to define logical and numerical variables and constants. The variables can capture output from SOAP orbital-prediction and geometric-engine computations. The module can combine variables and constants with built-in logical operators (such as Boolean AND, OR, and NOT), relational operators (such as >, <, or =), and mathematical operators (such as addition, subtraction, multiplication, division, modulus, exponentiation, differentiation, and integration). Parentheses can be used to specify precedence of operations. The module contains a library of mathematical functions and operations, including logarithms, trigonometric functions, Bessel functions, minimum/ maximum operations, and floating- point-to-integer conversions. The module supports combinations of time, distance, and angular units and has a dimensional- analysis component that checks for correct usage of units. A parser based on the Flex language and the Bison program looks for and indicates errors in syntax. SOAP expressions can be built using other expressions as arguments, thus enabling the user to build analytical trees. A graphical user interface facilitates use.
Author
SATELLITE ORBITS; FLOATING POINT ARITHMETIC; BESSEL FUNCTIONS; BOOLEAN ALGEBRA; DIMENSIONAL ANALYSIS; GRAPHICAL USER INTERFACE; TRIGONOMETRIC FUNCTIONS; PARSING ALGORITHMS
20080047994 California Inst. of Tech., Pasadena, CA, United States
Using LDPC Code Constraints to Aid Recovery of Symbol Timing
Jones, Christopher; Villasnor, John; Lee, Dong-U; Vales, Esteban; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English; Original contains color illustrations
Report No.(s): NPO-43112; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3268
A method of utilizing information available in the constraints imposed by a low-density parity-check (LDPC) code has been proposed as a means of aiding the recovery of symbol timing in the reception of a binary-phase-shift-keying (BPSK) signal representing such a code in the presence of noise, timing error, and/or Doppler shift between the transmitter and the receiver. This method and the receiver architecture in which it would be implemented belong to a class of timing-recovery methods and corresponding receiver architectures characterized as pilotless in that they do not require transmission and reception of pilot signals. Acquisition and tracking of a signal of the type described above have traditionally been performed upstream of, and independently of, decoding and have typically involved utilization of a phase-locked loop (PLL). However, the LDPC decoding process, which is iterative, provides information that can be fed back to the timing-recovery receiver circuits to improve performance significantly over that attainable in the absence of such feedback. Prior methods of coupling LDPC decoding with timing recovery had focused on the use of output code words produced as the iterations progress. In contrast, in the present method, one exploits the information available from the metrics computed for the constraint nodes of an LDPC code during the decoding process. In addition, the method involves the use of a waveform model that captures, better than do the waveform models of the prior methods, distortions introduced by receiver timing errors and transmitter/ receiver motions. An LDPC code is commonly represented by use of a bipartite graph containing two sets of nodes. In the graph corresponding to an (n,k) code, the n variable nodes correspond to the code word symbols and the n-k constraint nodes represent the constraints that the code places on the variable nodes in order for them to form a valid code word. The decoding procedure involves iterative computation of values associated with these nodes. A constraint node represents a parity-check equation using a set of variable nodes as inputs. A valid decoded code word is obtained if all parity-check equations are satisfied. After each iteration, the metrics associated with each constraint node can be evaluated to determine the status of the associated parity check. Heretofore, normally, these metrics would be utilized only within the LDPC decoding process to assess whether or not variable nodes had converged to a codeword. In the present method, it is recognized that these metrics can be used to determine accuracy of the timing estimates used in acquiring the sampled data that constitute the input to the LDPC decoder. In fact, the number of constraints that are satisfied exhibits a peak near the optimal timing estimate. Coarse timing estimation (or first-stage estimation as described below) is found via a parametric search for this peak. The present method calls for a two-stage receiver architecture illustrated in the figure. The first stage would correct large time delays and frequency offsets; the second stage would track random walks and correct residual time and frequency offsets. In the first stage, constraint-node feedback from the LDPC decoder would be employed in a search algorithm in which the searches would be performed in successively narrower windows to find the correct time delay and/or frequency offset. The second stage would include a conventional first-order PLL with a decision-aided timing-error detector that would utilize, as its decision aid, decoded symbols from the LDPC decoder. The method has been tested by means of computational simulations in cases involving various timing and frequency errors. The results of the simulations ined in the ideal case of perfect timing in the receiver.
Author (revised)
ERROR CORRECTING CODES; TIME MEASUREMENT; BINARY PHASE SHIFT KEYING; DECODING; RECEIVERS; TRANSMITTERS; SIGNAL PROCESSING
20080047995 California Inst. of Tech., Pasadena, CA, United States
DMAC and NMP as Electrolyte Additives for Li-Ion Cells
Smart, Marshall; Bugga, Ratnakumar; Lucht, Brett; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English; Original contains color illustrations
Report No.(s): NPO-44805; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3294
Dimethyl acetamide (DMAC) and N-methyl pyrrolidinone (NMP) have been found to be useful as high-temperature-resilience-enhancing additives to a baseline electrolyte used in rechargeable lithium-ion electrochemical cells. The baseline electrolyte, which was previously formulated to improve low-temperature performance, comprises LiPF6 dissolved at a concentration of 1.0 M in a mixture comprising equal volume proportions of ethylene carbonate, diethyl carbonate, and dimethyl carbonate. This and other electrolytes comprising lithium salts dissolved in mixtures of esters (including alkyl carbonates) have been studied in continuing research directed toward extending the lower limits of operating temperatures and, more recently, enhancing the high-temperature resilience of such cells. This research at earlier stages, and the underlying physical and chemical principles, were reported in numerous previous NASA Tech Briefs articles. Although these electrolytes provide excellent performance at low temperatures (typically as low as -40 C), when the affected Li-ion cells are subjected to high temperatures during storage and cycling, there occur irreversible losses of capacity accompanied by power fade and deterioration of low-temperature performance. The term "high-temperature resilience" signifies, loosely, the ability of a cell to resist such deterioration, retaining as much as possible of its initial charge/discharge capacity during operation or during storage in the fully charged condition at high temperature. For the purposes of the present development, a temperature is considered to be high if it equals or exceeds the upper limit (typically, 30 C) of the operating-temperature range for which the cells in question are generally designed.
Author
ADDITIVES; METHYL COMPOUNDS; ELECTROLYTES; LITHIUM; ETHYL COMPOUNDS; ELECTROCHEMICAL CELLS; METAL IONS
20080047996 Monitor Instruments Co., LLC, Cheswick, PA, United States
Mass Spectrometer Containing Multiple Fixed Collectors
Moskala, Robert; Celo, Alan; Voss, Guenter; Shaffer, Tom; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English; Original contains color illustrations
Report No.(s): KSC-12793/936; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3295
A miniature mass spectrometer that incorporates features not typically found in prior mass spectrometers is undergoing development. This mass spectrometer is designed to simultaneously measure the relative concentrations of five gases (H2, He, N2, O2, and Ar) in air, over the relative-concentration range from 10(exp -6) to 1, during a sampling time as short as 1 second. It is intended to serve as a prototype of a product line of easy-to-use, portable, lightweight, highspeed, relatively inexpensive instruments for measuring concentrations of multiple chemical species in such diverse applications as detecting explosive or toxic chemicals in air, monitoring and controlling industrial processes, measuring concentrations of deliberately introduced isotopes in medical and biological investigations, and general environmental monitoring. The heart of this mass spectrometer is an integral combination of a circular cycloidal mass analyzer, multiple fixed ion collectors, and two mass-selective ion sources. By circular cycloidal mass analyzer is meant an analyzer that includes (1) two concentric circular cylindrical electrodes for applying a radial electric field and (2) a magnet arranged to impose a magnetic flux aligned predominantly along the cylindrical axis, so that ions, once accelerated into the annulus between the electrodes, move along circular cycloidal trajectories. As in other mass analyzers, trajectory of each ion is determined by its mass-to-charge ratio, and so ions of different species can be collected simultaneously by collectors (Faraday cups) at different locations intersected by the corresponding trajectories (see figure). Unlike in other mass analyzers, the installation of additional collectors to detect additional species does not necessitate increasing the overall size of the analyzer assembly.
Author
HYDROGEN; HELIUM; NITROGEN; OXYGEN; ARGON; MASS SPECTROMETERS; GAS COMPOSITION; TOXICITY; ION SOURCES; AIR QUALITY
20080047997 NASA Glenn Research Center, Cleveland, OH, United States
Method for Thermal Spraying of Coatings Using Resonant-Pulsed Combustion
Paxson, Daniel E.; NASA Tech Briefs, October 2008; October 2008; pp. 13-1; In English; Original contains color illustrations
Report No.(s): LEW-18221-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3271
A method has been devised for high-volume, high-velocity surface deposition of protective metallic coatings on otherwise vulnerable surfaces. Thermal spraying is used whereby the material to be deposited is heated to the melting point by passing through a flame. Rather than the usual method of deposition from the jet formed from the combustion products, this innovation uses non-steady combustion (i.e. high-frequency, periodic, confined bursts), which generates not only higher temperatures and heat transfer rates, but exceedingly high impingement velocities an order of magnitude higher than conventional thermal systems. Higher impingement rates make for better adhesion. The high heat transfer rates developed here allow the deposition material to be introduced, not as an expensive powder with high surface-area-to-volume, but in convenient rod form, which is also easier and simpler to feed into the system. The nonsteady, resonant combustion process is self-aspirating and requires no external actuation or control and no high-pressure supply of fuel or air. The innovation has been demonstrated using a commercially available resonant combustor shown in the figure. Fuel is naturally aspirated from the tank through the lower Tygon tube and into the pulsejet. Air for starting is ported through the upper Tygon tube line. Once operation commences, this air is no longer needed as additional air is naturally aspirated through the inlet. A spark plug on the device is needed for starting, but the process carries on automatically as the operational device is resonant and reignites itself with each 220-Hz pulse.
Author
PROTECTIVE COATINGS; COMBUSTION PRODUCTS; HEAT TRANSFER; HIGH PRESSURE; POWDER (PARTICLES); PULSEJET ENGINES; ADHESION; MELTING POINTS
20080047998 California Inst. of Tech., Pasadena, CA, United States
Providing Internet Access to High-Resolution Lunar Images
Plesea, Lucian; NASA Tech Briefs, October 2008; October 2008; pp. 17-1; In English
Report No.(s): NPO-45951; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3278
The OnMoon server is a computer program that provides Internet access to high-resolution Lunar images, maps, and elevation data, all suitable for use in geographical information system (GIS) software for generating images, maps, and computational models of the Moon. The OnMoon server implements the Open Geospatial Consortium (OGC) Web Map Service (WMS) server protocol and supports Moon-specific extensions. Unlike other Internet map servers that provide Lunar data using an Earth coordinate system, the OnMoon server supports encoding of data in Moon-specific coordinate systems. The OnMoon server offers access to most of the available high-resolution Lunar image and elevation data. This server can generate image and map files in the tagged image file format (TIFF) or the Joint Photographic Experts Group (JPEG), 8- or 16-bit Portable Network Graphics (PNG), or Keyhole Markup Language (KML) format. Image control is provided by use of the OGC Style Layer Descriptor (SLD) protocol. Full-precision spectral arithmetic processing is also available, by use of a custom SLD extension. This server can dynamically add shaded relief based on the Lunar elevation to any image layer. This server also implements tiled WMS protocol and super-overlay KML for high-performance client application programs.
Author
LUNAR MAPS; COMPUTER PROGRAMS; HIGH RESOLUTION; PHOTOGRAPHS; COORDINATES; DOCUMENT MARKUP LANGUAGES; INTERNETS
20080047999 California Inst. of Tech., Pasadena, CA, United States
Whispering Gallery Mode Resonator with Orthogonally Reconfigurable Filter Function
Maleki, Lute; Matsko, Andrey; Strekalov, Dmitry; Savchenkov, Anatoliy; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English
Report No.(s): NPO-44948; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3299
An optical resonator has been developed with reconfigurable filter function that has resonant lines that can be shifted precisely and independently from each other, creating any desirable combination of resonant lines. This is achieved by changing the axial distribution of the effective refractive index of the resonator, which shifts the resonant frequency of particular optical modes, leaving all the rest unchanged. A reconfigurable optical filter is part of the remote chemical detector proposed for the Mars mission (Planetary Instrument Definition and Development Program PIDDP), but it is also useful for photonic communications devices.
Author
OPTICAL RESONATORS; WHISPERING GALLERY MODES; RECONFIGURABLE HARDWARE; OPTICAL FILTERS
20080048000 California Inst. of Tech., Pasadena, CA, United States
Waveguide Harmonic Generator for the SIM
Chang, Daniel; Poberezhskiy, Ilya; Mulder, Jerry; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English
Report No.(s): NPO-45253; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3297
A second-harmonic generator (SHG) serves as the source of the visible laser beam in an onboard calibration scheme for NASA's planned Space Interferometry Mission (SIM), which requires an infrared laser beam and a visible laser beam coherent with the infrared laser beam. The SHG includes quasi-phase-matched waveguides made of MgO-doped, periodically poled lithium niobate, pigtailed with polarization- maintaining optical fibers. Frequency doubling by use of such waveguides affords the required combination of coherence and sufficient conversion efficiency for the intended application. The spatial period of the poling is designed to obtain quasi-phase- matching at a nominal middle excitation wavelength of 1,319.28 nm. The SHG is designed to operate at a warm bias (ambient temperature between 20 and 25 C) that would be maintained in its cooler environment by use of electric heaters; the heater power would be adjusted to regulate the temperature precisely and thereby maintain the required precision of the spatial period. At the state of development at the time of this reporting, the SHG had been packaged and subjected to most of its planned space-qualification tests.
Author
HARMONIC GENERATORS; WAVEGUIDES; INTERFEROMETRY; LASER BEAMS; ELECTRO-OPTICS
20080048001 California Inst. of Tech., Pasadena, CA, United States; Aerospace Corp., Pasadena, CA, United States
Scripting Module for the Satellite Orbit Analysis Program (SOAP)
Carnright, Robert; Paget, Jim; Coggi, John; Stodden, David; NASA Tech Briefs, October 2008; October 2008; pp. 18-1; In English
Report No.(s): NPO-45055; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3282
This add-on module to the SOAP software can perform changes to simulation objects based on the occurrence of specific conditions. This allows the software to encompass simulation response of scheduled or physical events. Users can manipulate objects in the simulation environment under programmatic control. Inputs to the scripting module are Actions, Conditions, and the Script. Actions are arbitrary modifications to constructs such as Platform Objects (i.e. satellites), Sensor Objects (representing instruments or communication links), or Analysis Objects (user-defined logical or numeric variables). Examples of actions include changes to a satellite orbit ( v), changing a sensor-pointing direction, and the manipulation of a numerical expression. Conditions represent the circumstances under which Actions are performed and can be couched in If-Then-Else logic, like performing v at specific times or adding to the spacecraft power only when it is being illuminated by the Sun. The SOAP script represents the entire set of conditions being considered over a specific time interval. The output of the scripting module is a series of events, which are changes to objects at specific times. As the SOAP simulation clock runs forward, the scheduled events are performed. If the user sets the clock back in time, the events within that interval are automatically undone. This script offers an interface for defining scripts where the user does not have to remember the vocabulary of various keywords. Actions can be captured by employing the same user interface that is used to define the objects themselves. Conditions can be set to invoke Actions by selecting them from pull-down lists. Users define the script by selecting from the pool of defined conditions. Many space systems have to react to arbitrary events that can occur from scheduling or from the environment. For example, an instrument may cease to draw power when the area that it is tasked to observe is not in view. The contingency of the planetary body blocking the line of sight is a condition upon which the power being drawn is set to zero. It remains at zero until the observation objective is again in view. Computing the total power drawn by the instrument over a period of days or weeks can now take such factors into consideration. What makes the architecture especially powerful is that the scripting module can look ahead and behind in simulation time, and this temporal versatility can be leveraged in displays such as x-y plots. For example, a plot of a satellite s altitude as a function of time can take changes to the orbit into account.
Author
COMPUTER PROGRAMS; COMPUTERIZED SIMULATION; ORBITS; SPACE MISSIONS
20080048002 California Inst. of Tech., Pasadena, CA, United States
VHF Wide-Band, Dual-Polarization Microstrip-Patch Antenna
Huang, John; NASA Tech Briefs, October 2008; October 2008; pp. 9-1; In English; Original contains color illustrations
Report No.(s): NPO-41502; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3267
The figure depicts selected aspects of a very-high-frequency (VHF) microstrip patch antenna designed and built to satisfy requirements specific to an airborne synthetic-aperture radar system for measuring the thickness of sea ice. One of the requirements is that the antenna be capable of functioning over the relatively wide frequency band of 127 to 172 MHz corresponding to a fractional bandwidth of about 30 percent relative to a nominal mid-band frequency of 149.5 MHz. Another requirement is that the antenna be capable of functioning in either or both of two orthogonal linear polarizations. In addition, the antenna is required to be as compact and lightweight as possible. In a basic design according to generally accepted microstrip-patch-antenna engineering practice, one would ordinarily use a relatively thick dielectric substrate and multiple feed probes to obtain the desired combination of wide-band and dual-polarization capabilities. However, the combination of a thick substrate and multiple feeds would give rise to higher-order electromagnetic nodes, thereby undesirably contributing to cross polarization and to reduction of the isolation between feed probes. To counter these adverse effects while satisfying the requirements stated above, the design of this antenna incorporates several improvements over the basic design.
Derived from text
MICROSTRIP ANTENNAS; PATCH ANTENNAS; POLARIZATION; DIELECTRICS
20080048003 California Inst. of Tech., Pasadena, CA, United States
Algorithm for Wavefront Sensing Using an Extended Scene
Sidick, Erkin; Green, Joseph; Ohara, Catherine; NASA Tech Briefs, October 2008; October 2008; pp. ; In English
Report No.(s): NPO-44770; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3264
A recently conceived algorithm for processing image data acquired by a Shack-Hartmann (SH) wavefront sensor is not subject to the restriction, previously applicable in SH wavefront sensing, that the image be formed from a distant star or other equivalent of a point light source. That is to say, the image could be of an extended scene. (One still has the option of using a point source.) The algorithm can be implemented in commercially available software on ordinary computers. The steps of the algorithm are the following: 1. Suppose that the image comprises M sub-images. Determine the x,y Cartesian coordinates of the centers of these sub-images and store them in a 2xM matrix. 2. Within each sub-image, choose an NxN-pixel cell centered at the coordinates determined in step 1. For the ith sub-image, let this cell be denoted as si(x,y). Let the cell of another subimage (preferably near the center of the whole extended-scene image) be designated a reference cell, denoted r(x,y). 3. Calculate the fast Fourier transforms of the sub-sub-images in the central NxN portions (where N < N and both are preferably powers of 2) of r(x,y) and si(x,y). 4. Multiply the two transforms to obtain a cross-correlation function Ci(u,v), in the Fourier domain. Then let the phase of Ci(u, v) constitute a phase function, phi(u,v). 5. Fit u and v slopes to phi (u,v) over a small u,v subdomain. 6. Compute the fast Fourier transform, Si(u,v) of the full NxN cell si(x,y). Multiply this transform by the u and phase slopes obtained in step 4. Then compute the inverse fast Fourier transform of the product. 7. Repeat steps 4 through 6 in an iteration loop, cumulating the u and slopes, until a maximum iteration number is reached or the change in image shift becomes smaller than a predetermined tolerance. 8. Repeat steps 4 through 7 for the cells of all other sub-images.
Author
ALGORITHMS; ITERATION; WAVE FRONTS; DETECTION; POINT SOURCES
20080048004 Rochester Inst. of Tech., NY, United States
Improved Airborne System for Sensing Wildfires
McKeown, Donald; Richardson, Michael; NASA Tech Briefs, October 2008; October 2008; pp. 7-; In English; Original contains color illustrations
Report No.(s): SSC-00241; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3256
The Wildfire Airborne Sensing Program (WASP) is engaged in a continuing effort to develop an improved airborne instrumentation system for sensing wildfires. The system could also be used for other aerial-imaging applications, including mapping and military surveillance. Unlike prior airborne fire-detection instrumentation systems, the WASP system would not be based on custom-made multispectral line scanners and associated custom- made complex optomechanical servomechanisms, sensors, readout circuitry, and packaging. Instead, the WASP system would be based on commercial off-the-shelf (COTS) equipment that would include (1) three or four electronic cameras (one for each of three or four wavelength bands) instead of a multispectral line scanner; (2) all associated drive and readout electronics; (3) a camera-pointing gimbal; (4) an inertial measurement unit (IMU) and a Global Positioning System (GPS) receiver for measuring the position, velocity, and orientation of the aircraft; and (5) a data-acquisition subsystem. It would be necessary to custom-develop an integrated sensor optical-bench assembly, a sensor-management subsystem, and software. The use of mostly COTS equipment is intended to reduce development time and cost, relative to those of prior systems.
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AERIAL RECONNAISSANCE; FIRES; DETECTION; INERTIAL PLATFORMS; SYSTEMS ENGINEERING; IMAGING TECHNIQUES
20080048005 California Inst. of Tech., Pasadena, CA, United States
Small-Body Extensions for the Satellite Orbit Analysis Program (SOAP)
Carnright, Robert; Stodden, David; Coggi, John; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-45054; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3281
An extension to the SOAP software allows users to work with tri-axial ellipsoid-based representations of planetary bodies, primarily for working with small, natural satellites, asteroids, and comets. SOAP is a widely used tool for the visualization and analysis of space missions. The small body extension provides the same visualization and analysis constructs for use with small bodies. These constructs allow the user to characterize satellite path and instrument cover information for small bodies in both 3D display and numerical output formats. Tri-axial ellipsoids are geometric shapes the diameters of which are different in each of three principal x, y, and z dimensions. This construct provides a better approximation than using spheres or oblate spheroids (ellipsoids comprising two common equatorial diameters as a distinct polar diameter). However, the tri-axial ellipsoid is considerably more difficult to work with from a modeling perspective. In addition, the SOAP small-body extensions allow the user to actually employ a plate model for highly irregular surfaces. Both tri-axial ellipsoids and plate models can be assigned to coordinate frames, thus allowing for the modeling of arbitrary changes to body orientation. A variety of features have been extended to support tri-axial ellipsoids, including the computation and display of the spacecraft sub-orbital point, ground trace, instrument footprints, and swathes. Displays of 3D instrument volumes can be shown interacting with the ellipsoids. Longitude/latitude grids, contour plots, and texture maps can be displayed on the ellipsoids using a variety of projections. The distance along an arbitrary line of sight can be computed between the spacecraft and the ellipsoid, and the coordinates of that intersection can be plotted as a function of time. The small-body extension supports the same visual and analytical constructs that are supported for spheres and oblate spheroids in SOAP making the implementation of the more complex algorithms largely transparent to the user.
Author
COMPUTER PROGRAMS; SCIENTIFIC VISUALIZATION; SPACE MISSIONS; ORBITS
20080048006 California Inst. of Tech., Pasadena, CA, United States
The Interplanetary Overlay Networking Protocol Accelerator
Pang, Jackson; Torgerson, Jordan L.; Clare, Loren P.; NASA Tech Briefs, October 2008; October 2008; pp. 3; In English
Report No.(s): NPO-45584; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3317
A document describes the Interplanetary Overlay Networking Protocol Accelerator (IONAC) an electronic apparatus, now under development, for relaying data at high rates in spacecraft and interplanetary radio-communication systems utilizing a delay-tolerant networking protocol. The protocol includes provisions for transmission and reception of data in bundles (essentially, messages), transfer of custody of a bundle to a recipient relay station at each step of a relay, and return receipts. Because of limitations on energy resources available for such relays, data rates attainable in a conventional software implementation of the protocol are lower than those needed, at any given reasonable energy-consumption rate. Therefore, a main goal in developing the IONAC is to reduce the energy consumption by an order of magnitude and the data-throughput capability by two orders of magnitude. The IONAC prototype is a field-programmable gate array that serves as a reconfigurable hybrid (hardware/ firmware) system for implementation of the protocol. The prototype can decode 108,000 bundles per second and encode 100,000 bundles per second. It includes a bundle-cache static randomaccess memory that enables maintenance of a throughput of 2.7Gb/s, and an Ethernet convergence layer that supports a duplex throughput of 1Gb/s.
Author
PROTOCOL (COMPUTERS); RADIO COMMUNICATION; COMPUTER NETWORKS; RECONFIGURABLE HARDWARE
20080048007 California Inst. of Tech., Pasadena, CA, United States
Bimaterial Thermal Compensators for WGM Resonators
Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute; Iltchenko, Vladimir; Strekalov, Dmitry; NASA Tech Briefs, October 2008; October 2008; pp. 28-2; In English; Original contains color illustrations
Report No.(s): NPO-44441; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3300
Bimaterial thermal compensators have been proposed as inexpensive means of preventing (to first order) or reducing temperature-related changes in the resonance frequencies of whispering-gallery-mode (WGM) optical resonators. A bimaterial compensator would apply, to a WGM resonator, a pressure that would slightly change the shape of the resonator and thereby change its resonance frequencies. Through suitable choice of the compensator dimensions and materials, it should be possible to make the temperature dependence of the pressure-induced frequency shift equal in magnitude and opposite in sign to the temperature dependence of the frequency shift of the uncompensated resonator so that, to first order, a change in temperature would cause zero net change in frequency.
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COMPENSATORS; WHISPERING GALLERY MODES; MATERIALS; OPTICAL RESONATORS
20080048008 NASA Kennedy Space Center, Cocoa Beach, FL, United States
Coating Reduces Ice Adhesion
Smith, Trent; Prince, Michael; DwWeese, Charles; Curtis, Leslie; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): KSC-13100/1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3272
The Shuttle Ice Liberation Coating (SILC) has been developed to reduce the adhesion of ice to surfaces on the space shuttle. SILC, when coated on a surface (foam, metal, epoxy primer, polymer surfaces), will reduce the adhesion of ice by as much as 90 percent as compared to the corresponding uncoated surface. This innovation is a durable coating that can withstand several cycles of ice growth and removal without loss of anti-adhesion properties. SILC is made of a binder composed of varying weight percents of siloxane(s), ethyl alcohol, ethyl sulfate, isopropyl alcohol, and of fine-particle polytetrafluoroethylene (PTFE). The combination of these components produces a coating with significantly improved weathering characteristics over the siloxane system alone. In some cases, the coating will delay ice formation and can reduce the amount of ice formed. SILC is not an ice prevention coating, but the very high water contact angle (greater than 140 ) causes water to readily run off the surface. This coating was designed for use at temperatures near -170 F (-112 C). Ice adhesion tests performed at temperatures from -170 to 20 F (-112 to -7 C) show that SILC is a very effective ice release coating. SILC can be left as applied (opaque) or buffed off until the surface appears clear. Energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) data show that the coating is still present after buffing to transparency. This means SILC can be used to prevent ice adhesion even when coating windows or other objects, or items that require transmission of optical light. Car windshields are kept cleaner and SILC effectively mitigates rain and snow under driving conditions.
Author
SILOXANES; ETHYL ALCOHOL; SULFATES; ISOPROPYL ALCOHOL; POLYTETRAFLUOROETHYLENE; ICE PREVENTION; ADHESION TESTS; SURFACE PROPERTIES
20080048009 California Inst. of Tech., Pasadena, CA, United States
Making Superconducting Welds between Superconducting Wires
Penanen, Konstantin I.; Eom, Byeong Ho; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English; Original contains color illustrations
Report No.(s): NPO-45931; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3270
A technique for making superconducting joints between wires made of dissimilar superconducting metals has been devised. The technique is especially suitable for fabrication of superconducting circuits needed to support persistent electric currents in electromagnets in diverse cryogenic applications. Examples of such electromagnets include those in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) systems and in superconducting quantum interference devices (SQUIDs). Sometimes, it is desirable to fabricate different parts of a persistent-current-supporting superconducting loop from different metals. For example, a sensory coil in a SQUID might be made of Pb, a Pb/Sn alloy, or a Cu wire plated with Pb/Sn, while the connections to the sensory coil might be made via Nb or Nb/Ti wires. Conventional wire-bonding techniques, including resistance spot welding and pressed contact, are not workable because of large differences between the hardnesses and melting temperatures of the different metals. The present technique is not subject to this limitation. The present technique involves the use (1) of a cheap, miniature, easy-to-operate, capacitor-discharging welding apparatus that has an Nb or Nb/Ti tip and operates with a continuous local flow of gaseous helium and (2) preparation of a joint in a special spark-discharge welding geometry. In a typical application, a piece of Nb foil about 25 m thick is rolled to form a tube, into which is inserted a wire that one seeks to weld to the tube (see figure). The tube can be slightly crimped for mechanical stability. Then a spark weld is made by use of the aforementioned apparatus with energy and time settings chosen to melt a small section of the niobium foil. The energy setting corresponds to the setting of a voltage to which the capacitor is charged. In an experiment, the technique was used to weld an Nb foil to a copper wire coated with a Pb/Sn soft solder, which is superconducting. The joint was evaluated as part of a persistent-current circuit having an inductance of 1 mH. A current was induced in a loop, and no attenuation of the current after a time interval 1,000 s was discernible in a measurement having a fractional accuracy of 10(exp -4): This observation supports the conclusion that the weld had an electrical resistance <10(exp -10) omega.
Author
BONDING; SUPERCONDUCTIVITY; WELDED JOINTS; WIRE; NUCLEAR MAGNETIC RESONANCE; ELECTRIC POTENTIAL; METAL FOILS; CONTINUUM FLOW; ELECTRIC CURRENT
20080048010 California Inst. of Tech., Pasadena, CA, United States
Mars Image Collection Mosaic Builder
Plesea, Lucian; Hare, Trent; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-45960; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3276
A computer program assembles images from the Mars Global Surveyor (MGS) Mars Observer Camera Narrow Angle (MOCNA) collection to generate a uniform-high-resolution, georeferenced, uncontrolled mosaic image of the Martian surface. At the time of reporting the information for this article, the mosaic covered 7 percent of the Martian surface and contained data from more than 50,000 source images acquired under various light conditions at various resolutions.
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MARS SURFACE; APPLICATIONS PROGRAMS (COMPUTERS); MOSAICS; IMAGE ENHANCEMENT; IMAGING TECHNIQUES
20080048011 Hammers Co., Greenbelt, MD, United States
Virtual Satellite
Hammrs, Stephan R.; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): GSC-14824-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3280
Virtual Satellite (VirtualSat) is a computer program that creates an environment that facilitates the development, verification, and validation of flight software for a single spacecraft or for multiple spacecraft flying in formation. In this environment, enhanced functionality and autonomy of navigation, guidance, and control systems of a spacecraft are provided by a virtual satellite that is, a computational model that simulates the dynamic behavior of the spacecraft. Within this environment, it is possible to execute any associated software, the development of which could benefit from knowledge of, and possible interaction (typically, exchange of data) with, the virtual satellite. Examples of associated software include programs for simulating spacecraft power and thermal- management systems. This environment is independent of the flight hardware that will eventually host the flight software, making it possible to develop the software simultaneously with, or even before, the hardware is delivered. Optionally, by use of interfaces included in VirtualSat, hardware can be used instead of simulated. The flight software, coded in the C or C++ programming language, is compilable and loadable into VirtualSat without any special modifications. Thus, VirtualSat can serve as a relatively inexpensive software test-bed for development test, integration, and post-launch maintenance of spacecraft flight software.
Author
APPLICATIONS PROGRAMS (COMPUTERS); FLIGHT CONTROL; SPACECRAFT GUIDANCE; FORMATION FLYING; COMPUTER PROGRAMS; DYNAMIC CHARACTERISTICS; GUIDANCE (MOTION); NAVIGATION
20080048012 Brown (Richard Lee), United States
Root Source Analysis/ValuStream[Trade Mark] - A Methodology for Identifying and Managing Risks
Brown, Richard Lee; NASA Tech Briefs, October 2008; October 2008; pp. 3; In English
Report No.(s): MFS-32316-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3309
Root Source Analysis (RoSA) is a systems engineering methodology that has been developed at NASA over the past five years. It is designed to reduce costs, schedule, and technical risks by systematically examining critical assumptions and the state of the knowledge needed to bring to fruition the products that satisfy mission-driven requirements, as defined for each element of the Work (or Product) Breakdown Structure (WBS or PBS). This methodology is sometimes referred to as the ValuStream method, as inherent in the process is the linking and prioritizing of uncertainties arising from knowledge shortfalls directly to the customer's mission driven requirements. RoSA and ValuStream are synonymous terms. RoSA is not simply an alternate or improved method for identifying risks. It represents a paradigm shift. The emphasis is placed on identifying very specific knowledge shortfalls and assumptions that are the root sources of the risk (the why), rather than on assessing the WBS product(s) themselves (the what). In so doing RoSA looks forward to anticipate, identify, and prioritize knowledge shortfalls and assumptions that are likely to create significant uncertainties/ risks (as compared to Root Cause Analysis, which is most often used to look back to discover what was not known, or was assumed, that caused the failure). Experience indicates that RoSA, with its primary focus on assumptions and the state of the underlying knowledge needed to define, design, build, verify, and operate the products, can identify critical risks that historically have been missed by the usual approaches (i.e., design review process and classical risk identification methods). Further, the methodology answers four critical questions for decision makers and risk managers: 1. What s been included? 2. What's been left out? 3. How has it been validated? 4. Has the real source of the uncertainty/ risk been identified, i.e., is the perceived problem the real problem? Users of the RoSA methodology have characterized it as a true bottoms up risk assessment.
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SYSTEMS ENGINEERING; RISK MANAGEMENT; METHODOLOGY; PROJECT MANAGEMENT
20080048013 California Inst. of Tech., Pasadena, CA, United States
Ensemble: an Architecture for Mission-Operations Software
Norris, Jeffrey; Powell, Mark; Fox, Jason; Rabe, Kenneth; Shu, IHsiang; McCurdy, Michael; Vera, Alonso; NASA Tech Briefs, October 2008; October 2008; pp. 3; In English
Report No.(s): NPO-41814; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3310
Ensemble is the name of an open architecture for, and a methodology for the development of, spacecraft mission operations software. Ensemble is also potentially applicable to the development of non-spacecraft mission-operations- type software. Ensemble capitalizes on the strengths of the open-source Eclipse software and its architecture to address several issues that have arisen repeatedly in the development of mission-operations software: Heretofore, mission-operations application programs have been developed in disparate programming environments and integrated during the final stages of development of missions. The programs have been poorly integrated, and it has been costly to develop, test, and deploy them. Users of each program have been forced to interact with several different graphical user interfaces (GUIs). Also, the strategy typically used in integrating the programs has yielded serial chains of operational software tools of such a nature that during use of a given tool, it has not been possible to gain access to the capabilities afforded by other tools. In contrast, the Ensemble approach offers a low-risk path towards tighter integration of mission-operations software tools.
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SOFTWARE ENGINEERING; ARCHITECTURE (COMPUTERS); APPLICATIONS PROGRAMS (COMPUTERS); MISSION PLANNING
20080048014 Geological Survey, United States
Providing Internet Access to High-Resolution Mars Images
Plesea, Lucian; NASA Tech Briefs, October 2008; October 2008; pp. 3; In English
Report No.(s): NPO-45959; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3277
The OnMars server is a computer program that provides Internet access to high-resolution Mars images, maps, and elevation data, all suitable for use in geographical information system (GIS) software for generating images, maps, and computational models of Mars. The OnMars server is an implementation of the Open Geospatial Consortium (OGC) Web Map Service (WMS) server. Unlike other Mars Internet map servers that provide Martian data using an Earth coordinate system, the OnMars WMS server supports encoding of data in Mars-specific coordinate systems. The OnMars server offers access to most of the available high-resolution Martian image and elevation data, including an 8-meter-per-pixel uncontrolled mosaic of most of the Mars Global Surveyor (MGS) Mars Observer Camera Narrow Angle (MOCNA) image collection, which is not available elsewhere. This server can generate image and map files in the tagged image file format (TIFF), Joint Photographic Experts Group (JPEG), 8- or 16-bit Portable Network Graphics (PNG), or Keyhole Markup Language (KML) format. Image control is provided by use of the OGC Style Layer Descriptor (SLD) protocol. The OnMars server also implements tiled WMS protocol and super-overlay KML for high-performance client application programs.
Author
DOCUMENT MARKUP LANGUAGES; PLANETARY MAPPING; MARS SURFACE; COMPUTER PROGRAMS; MARS GLOBAL SURVEYOR; PHOTOGRAPHS; COORDINATES; HIGH RESOLUTION; INTERNETS
20080048015 NASA Stennis Space Center, Stennis Space Center, MS, United States
Expert System Control of Plant Growth in an Enclosed Space
May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English; Original contains color illustrations
Report No.(s): SSC-00258,; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3292
The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.
Author
EXPERT SYSTEMS; VEGETATION GROWTH; CROP GROWTH; KNOWLEDGE BASED SYSTEMS; FARM CROPS; CULTIVATION; IMAGING TECHNIQUES; BIOMASS
20080048016 California Inst. of Tech., Pasadena, CA, United States
Hybrid Multifoil Aerogel Thermal Insulation
Sakamoto, Jeffrey; Paik, Jong-Ah; Jones, Steven; Nesmith, Bill; NASA Tech Briefs, October 2008; October 2008; pp. 15-1; In English; Original contains color illustrations
Report No.(s): NPO-45219; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3273
This innovation blends the merits of multifoil insulation (MFI) with aerogel-based insulation to develop a highly versatile, ultra-low thermally conductive material called hybrid multifoil aerogel thermal insulation (HyMATI). The density of the opacified aerogel is 240 mg/cm3 and has thermal conductivity in the 20 mW/mK range in high vacuum and 25 mW/mK in 1 atmosphere of gas (such as argon) up to 800 C. It is stable up to 1,000 C. This is equal to commercially available high-temperature thermal insulation. The thermal conductivity of the aerogel is 36 percent lower compared to several commercially available insulations when tested in 1 atmosphere of argon gas up to 800 C.
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AEROGELS; HIGH TEMPERATURE; THERMAL INSULATION; METAL FOILS
20080048017 NASA Glenn Research Center, Cleveland, OH, United States
CO2 Sensors Based on Nanocrystalline SnO2 Doped with CuO
Xu, Jennifer C.; Hunter, Gary W.; Liu, Chung Chiun; Ward, Benjamin J.; NASA Tech Briefs, October 2008; October 2008; pp. 6-; In English; Original contains color illustrations
Report No.(s): LEW-18247-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3263
Nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been found to be useful as an electrical-resistance sensory material for measuring the concentration of carbon dioxide in air. SnO2 is an n-type semiconductor that has been widely used as a sensing material for detecting such reducing gases as carbon monoxide, some of the nitrogen oxides, and hydrocarbons. Without doping, SnO2 usually does not respond to carbon dioxide and other stable gases. The discovery that the electrical resistance of CuO-doped SnO2 varies significantly with the concentration of CO2 creates opportunities for the development of relatively inexpensive CO2 sensors for detecting fires and monitoring atmospheric conditions. This discovery could also lead to research that could alter fundamental knowledge of SnO2 as a sensing material, perhaps leading to the development of SnO2-based sensing materials for measuring concentrations of oxidizing gases. Prototype CO2 sensors based on CuO-doped SnO2 have been fabricated by means of semiconductor-microfabrication and sol-gel nanomaterial-synthesis batch processes that are amendable to inexpensive implementation in mass production.
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CARBON DIOXIDE; CARBON MONOXIDE; COPPER OXIDES; FABRICATION; TIN OXIDES; NANOCRYSTALS
20080048018 California Inst. of Tech., Pasadena, CA, United States
Onboard Data Processor for Change-Detection Radar Imaging
Lou, Yunling; Muellerschoen, Ronald J.; Chien, Steve A.; Saatchi, Sasan S.; Clark, Duane; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English; Original contains color illustrations
Report No.(s): NPO-45751; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3265
A computer system denoted a change-detection onboard processor (CDOP) is being developed as a means of processing the digitized output of a synthetic-aperture radar (SAR) apparatus aboard an aircraft or spacecraft to generate images showing changes that have occurred in the terrain below between repeat passes of the aircraft or spacecraft over the terrain. When fully developed, the CDOP is intended to be capable of generating SAR images and/or SAR differential interferograms in nearly real time. The CDOP is expected to be especially useful for understanding some large-scale natural phenomena and/or mitigating natural hazards: For example, it could be used for near-real-time observation of surface changes caused by floods, landslides, forest fires, volcanic eruptions, earthquakes, glaciers, and sea ice movements. It could also be used to observe such longer-term surface changes as those associated with growth of vegetation (relevant to estimation of wildfire fuel loads). The CDOP is, essentially, an interferometric SAR processor designed to operate aboard a radar platform.
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ONBOARD DATA PROCESSING; CHANGE DETECTION; RADAR IMAGERY; SYNTHETIC APERTURE RADAR
20080048019 California Inst. of Tech., Pasadena, CA, United States
SHINE Virtual Machine Model for In-flight Updates of Critical Mission Software
Plesea, Lucian; NASA Tech Briefs, October 2008; October 2008; pp. 1; In English
Report No.(s): NPO-45959; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3275
This software is a new target for the Spacecraft Health Inference Engine (SHINE) knowledge base that compiles a knowledge base to a language called Tiny C - an interpreted version of C that can be embedded on flight processors. This new target allows portions of a running SHINE knowledge base to be updated on a "live" system without needing to halt and restart the containing SHINE application. This enhancement will directly provide this capability without the risk of software validation problems and can also enable complete integration of BEAM and SHINE into a single application. This innovation enables SHINE deployment in domains where autonomy is used during flight-critical applications that require updates. This capability eliminates the need for halting the application and performing potentially serious total system uploads before resuming the application with the loss of system integrity. This software enables additional applications at JPL (microsensors, embedded mission hardware) and increases the marketability of these applications outside of JPL.
Author
KNOWLEDGE BASED SYSTEMS; PROGRAM VERIFICATION (COMPUTERS); MICROINSTRUMENTATION; SENSORS; COMPUTER PROGRAMS; TARGETS; DEPLOYMENT
20080048020 California Inst. of Tech., Pasadena, CA, United States
An ATP System for Deep-Space Optical Communication
Lee, Shinhak; Irtuzm Gerardi; Alexander, James; NASA Tech Briefs, October 2008; October 2008; pp. 2; In English
Report No.(s): NPO-41736; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3289
An acquisition, tracking, and pointing (ATP) system is proposed for aiming an optical-communications downlink laser beam from deep space. In providing for a direction reference, the concept exploits the mature technology of star trackers to eliminate the need for a costly and potentially hazardous laser beacon. The system would include one optical and two inertial sensors, each contributing primarily to a different portion of the frequency spectrum of the pointing signal: a star tracker (<10 Hz), a gyroscope (<50 Hz), and a precise fluid-rotor inertial angular-displacement sensor (sometimes called, simply, "angle sensor") for the frequency range >50 Hz. The outputs of these sensors would be combined in an iterative averaging process to obtain high-bandwidth, high-accuracy pointing knowledge. The accuracy of pointing knowledge obtainable by use of the system was estimated on the basis of an 8-cm-diameter telescope and known parameters of commercially available star trackers and inertial sensors: The single-axis pointing-knowledge error was found to be characterized by a standard deviation of 150 nanoradians - below the maximum value (between 200 and 300 nanoradians) likely to be tolerable in deep-space optical communications.
Author
OPTICAL COMMUNICATION; TARGET ACQUISITION; FREQUENCY DISTRIBUTION; DISPLACEMENT; STAR TRACKERS; LASER BEAMS
20080048021 California Inst. of Tech., Pasadena, CA, United States
Control Architecture for Robotic Agent Command and Sensing
Huntsberger, Terrance; Aghazarian, Hrand; Estlin, Tara; Gaines, Daniel; NASA Tech Briefs, October 2008; October 2008; pp. ; In English; Original contains color illustrations
Report No.(s): NPO-43635; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3251
Control Architecture for Robotic Agent Command and Sensing (CARACaS) is a recent product of a continuing effort to develop architectures for controlling either a single autonomous robotic vehicle or multiple cooperating but otherwise autonomous robotic vehicles. CARACaS is potentially applicable to diverse robotic systems that could include aircraft, spacecraft, ground vehicles, surface water vessels, and/or underwater vessels. CARACaS incudes an integral combination of three coupled agents: a dynamic planning engine, a behavior engine, and a perception engine. The perception and dynamic planning en - gines are also coupled with a memory in the form of a world model. CARACaS is intended to satisfy the need for two major capabilities essential for proper functioning of an autonomous robotic system: a capability for deterministic reaction to unanticipated occurrences and a capability for re-planning in the face of changing goals, conditions, or resources. The behavior engine incorporates the multi-agent control architecture, called CAMPOUT, described in An Architecture for Controlling Multiple Robots (NPO-30345), NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 65. CAMPOUT is used to develop behavior-composition and -coordination mechanisms. Real-time process algebra operators are used to compose a behavior network for any given mission scenario. These operators afford a capability for producing a formally correct kernel of behaviors that guarantee predictable performance. By use of a method based on multi-objective decision theory (MODT), recommendations from multiple behaviors are combined to form a set of control actions that represents their consensus. In this approach, all behaviors contribute simultaneously to the control of the robotic system in a cooperative rather than a competitive manner. This approach guarantees a solution that is good enough with respect to resolution of complex, possibly conflicting goals within the constraints of the mission to be accomplished by the vehicle(s).
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ROBOTICS; ARCHITECTURE (COMPUTERS); SOFTWARE ENGINEERING; COMMAND AND CONTROL
20080048022 NASA, Washington, DC, United States
NASA Tech Briefs, December 2008
December 2008; In English; Original contains color illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Topics covered include: Crew Activity Analyzer; Distributing Data to Hand-Held Devices in a Wireless Network; Reducing Surface Clutter in Cloud Profiling Radar Data; MODIS Atmospheric Data Handler; Multibeam Altimeter Navigation Update Using Faceted Shape Model; Spaceborne Hybrid-FPGA System for Processing FTIR Data; FPGA Coprocessor for Accelerated Classification of Images; SiC JFET Transistor Circuit Model for Extreme Temperature Range; TDR Using Autocorrelation and Varying-Duration Pulses; Update on Development of SiC Multi-Chip Power Modules; Radio Ranging System for Guidance of Approaching Spacecraft; Electromagnetically Clean Solar Arrays; Improved Short-Circuit Protection for Power Cells in Series; Electromagnetically Clean Solar Arrays; Logic Gates Made of N-Channel JFETs and Epitaxial Resistors; Improved Short-Circuit Protection for Power Cells in Series; Communication Limits Due to Photon-Detector Jitter; System for Removing Pollutants from Incinerator Exhaust; Sealing and External Sterilization of a Sample Container; Converting EOS Data from HDF-EOS to netCDF; HDF-EOS 2 and HDF-EOS 5 Compatibility Library; HDF-EOS Web Server; HDF-EOS 5 Validator; XML DTD and Schemas for HDF-EOS; Converting from XML to HDF-EOS; Simulating Attitudes and Trajectories of Multiple Spacecraft; Specialized Color Function for Display of Signed Data; Delivering Alert Messages to Members of a Work Force; Delivering Images for Mars Rover Science Planning; Oxide Fiber Cathode Materials for Rechargeable Lithium Cells; Electrocatalytic Reduction of Carbon Dioxide to Methane; Heterogeneous Superconducting Low-Noise Sensing Coils; Progress toward Making Epoxy/Carbon-Nanotube Composites; Predicting Properties of Unidirectional-Nanofiber Composites; Deployable Crew Quarters; Nonventing, Regenerable, Lightweight Heat Absorber; Miniature High-Force, Long-Stroke SMA Linear Actuators; "Bootstrap" Configuration for Multistage Pulse-Tube Coolers; Reducing Liquid Loss during Ullage Venting in Microgravity; Ka-Band Transponder for Deep-Space Radio Science; Replication of Space-Shuttle Computers in FPGAs and ASICs; Demisable Reaction-Wheel Assembly; Spatial and Temporal Low-Dimensional Models for Fluid Flow; Advanced Land Imager Assessment System; Range Imaging without Moving Parts.
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AUTOCORRELATION; CARBON NANOTUBES; CIRCUIT PROTECTION; CONTAMINANTS; DOCUMENT MARKUP LANGUAGES; ELECTROCHEMICAL CELLS; EXTREMELY HIGH FREQUENCIES; FIELD-PROGRAMMABLE GATE ARRAYS; INFRARED SPECTRA; MICROGRAVITY; MODIS (RADIOMETRY); TRANSISTOR CIRCUITS; SUPERCONDUCTIVITY
20080048023 NASA Glenn Research Center, Cleveland, OH, United States
Update on Development of SiC Multi-Chip Power Modules
Lostetter, Alexander; Cilio, Edgar; Mitchell, Gavin; Schupbach, Roberto; NASA Tech Briefs, December 2008; December 2008; pp. 10-1; In English
Report No.(s): LEW-18341-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3421
Progress has been made in a continuing effort to develop multi-chip power modules (SiC MCPMs). This effort at an earlier stage was reported in 'SiC Multi-Chip Power Modules as Power-System Building Blocks' (LEW-18008-1), NASA Tech Briefs, Vol. 31, No. 2 (February 2007), page 28. The following recapitulation of information from the cited prior article is prerequisite to a meaningful summary of the progress made since then: 1) SiC MCPMs are, more specifically, electronic power-supply modules containing multiple silicon carbide power integrated-circuit chips and silicon-on-insulator (SOI) control integrated-circuit chips. SiC MCPMs are being developed as building blocks of advanced expandable, reconfigurable, fault-tolerant power-supply systems. Exploiting the ability of SiC semiconductor devices to operate at temperatures, breakdown voltages, and current densities significantly greater than those of conventional Si devices, the designs of SiC MCPMs and of systems comprising multiple SiC MCPMs are expected to afford a greater degree of miniaturization through stacking of modules with reduced requirements for heat sinking; 2) The stacked SiC MCPMs in a given system can be electrically connected in series, parallel, or a series/parallel combination to increase the overall power-handling capability of the system. In addition to power connections, the modules have communication connections. The SOI controllers in the modules communicate with each other as nodes of a decentralized control network, in which no single controller exerts overall command of the system. Control functions effected via the network include synchronization of switching of power devices and rapid reconfiguration of power connections to enable the power system to continue to supply power to a load in the event of failure of one of the modules; and, 3) In addition to serving as building blocks of reliable power-supply systems, SiC MCPMs could be augmented with external control circuitry to make them perform additional power-handling functions as needed for specific applications. Because identical SiC MCPM building blocks could be utilized in such a variety of ways, the cost and difficulty of designing new, highly reliable power systems would be reduced considerably. This concludes the information from the cited prior article. The main activity since the previously reported stage of development was the design, fabrication, and testing a 120- VDC-to-28-VDC modular power-converter system composed of eight SiC MCPMs in a 4 (parallel)-by-2 (series) matrix configuration, with normally-off controllable power switches. The SiC MCPM power modules include closed-loop control subsystems and are capable of operating at high power density or high temperature. The system was tested under various configurations, load conditions, load-transient conditions, and failure-recovery conditions. Planned future work includes refinement of the demonstrated modular system concept and development of a new converter hardware topology that would enable sharing of currents without the need for communication among modules. Toward these ends, it is also planned to develop a new converter control algorithm that would provide for improved sharing of current and power under all conditions, and to implement advanced packaging concepts that would enable operation at higher power density.
Author (revised)
SILICON CARBIDES; CHIPS (ELECTRONICS); INTEGRATED CIRCUITS; MODULES; SEMICONDUCTOR DEVICES; ELECTRICAL ENGINEERING
20080048024 California Inst. of Tech., Pasadena, CA, United States
Communication Limits Due to Photon-Detector Jitter
Moision, Bruce E.; Farr, William H.; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): NPO-45809; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3424
A theoretical and experimental study was conducted of the limit imposed by photon-detector jitter on the capacity of a pulse-position-modulated optical communication system in which the receiver operates in a photon-counting (weak-signal) regime. Photon-detector jitter is a random delay between impingement of a photon and generation of an electrical pulse by the detector. In the study, jitter statistics were computed from jitter measurements made on several photon detectors. The probability density of jitter was mathematically modeled by use of a weighted sum of Gaussian functions. Parameters of the model were adjusted to fit histograms representing the measured-jitter statistics. Likelihoods of assigning detector-output pulses to correct pulse time slots in the presence of jitter were derived and used to compute channel capacities and corresponding losses due to jitter. It was found that the loss, expressed as the ratio between the signal power needed to achieve a specified capacity in the presence of jitter and that needed to obtain the same capacity in the absence of jitter, is well approximated as a quadratic function of the standard deviation of the jitter in units of pulse-time-slot duration.
Author
PHOTOMETERS; VIBRATION; OPTICAL COMMUNICATION; SIGNAL PROCESSING
20080048025 NASA Kennedy Space Center, Cocoa Beach, FL, United States; ASRC Aerospace Corp., United States
TDR Using Autocorrelation and Varying-Duration Pulses
Lucena, Angel; Mullinex, Pam; Huang, PoTien; Santiago, Josephine; Mata, Carlos; Zavala, Carlos; Lane, John; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): KSC-12856; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3419
In an alternative to a prior technique of time-domain-reflectometry (TDR) in which very short excitation pulses are used, the pulses have very short rise and fall times and the pulse duration is varied continuously between a minimum and a maximum value. In both the present and prior techniques, the basic idea is to (1) measure the times between the generation of excitation pulses and the reception of reflections of the pulses as indications of the locations of one or more defects along a cable and (2) measure the amplitudes of the reflections as indication of the magnitudes of the defects. In general, an excitation pulse has a duration T. Each leading and trailing edge of an excitation pulse generates a reflection from a defect, so that a unique pair of reflections is associated with each defect. In the present alternative technique, the processing of the measured reflection signal includes computation of the autocorrelation function R(tau) identical with fx(t)x(t-tau)dt where t is time, x(t) is the measured reflection signal at time t, and taus is the correlation interval. The integration is performed over a measurement time interval short enough to enable identification and location of a defect within the corresponding spatial interval along the cable. Typically, where there is a defect, R(tau) exhibits a negative peak having maximum magnitude for tau in the vicinity of T. This peak can be used as a means of identifying a leading-edge/trailing-edge reflection pair. For a given spatial interval, measurements are made and R(tau) computed, as described above, for pulse durations T ranging from the minimum to the maximum value. The advantage of doing this is that the effective signal-to-noise ratio may be significantly increased over that attainable by use of a fixed pulse duration T.
Author
FAULT DETECTION; ELECTRONIC EQUIPMENT; TIME SIGNALS; SIGNAL REFLECTION; PULSE DURATION; AUTOCORRELATION
20080048026 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Converting from XML to HDF-EOS
Ullman, Richard; Bane, Bob; Yang, Jingli; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-15017-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3443
A computer program recreates an HDF-EOS file from an Extensible Markup Language (XML) representation of the contents of that file. This program is one of two programs written to enable testing of the schemas described in the immediately preceding article to determine whether the schemas capture all details of HDF-EOS files.
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COMPUTER PROGRAMS; DOCUMENT MARKUP LANGUAGES; DATA CONVERSION ROUTINES
20080048027 California Inst. of Tech., Pasadena, CA, United States
Sealing and External Sterilization of a Sample Container
Bar-Cohen, Yoseph; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Olorunsola, Ayoola; NASA Tech Briefs, December 2008; December 2008; pp. 15-1; In English; Original contains color illustrations
Report No.(s): NPO-45610; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3426
A method of (1) sealing a sample of possibly biologically environment outer surface of the container, sealed container The method now proposed was originally to return samples be environments that contain some
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STERILIZATION; HERMETIC SEALS; BIOLOGICAL HAZARDS
20080048028 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Converting EOS Data from HDF-EOS to netCDF
Ullman, Richard; Bame. Bob; Yang, Jingli; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-15007-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3435
A C-language computer program accepts, as input, a set of scientific data and metadata from an Earth Observing System (EOS) satellite and converts the set from (1) the format in which it was created and delivered to (2) another format for processing and exchange of data on Earth.
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COMPUTER PROGRAMS; DATA SYSTEMS; DATA CONVERSION ROUTINES
20080048029 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Range Imaging without Moving Parts
Blair, J. Bryan; Scott, V. Stanley, III; Ramos-Izquierdo, Luis; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): GSC-15184-1; Copyright; Avail.: CASI: A01, Hardcopy
Range-imaging instruments of a type now under development are intended to generate the equivalent of three-dimensional images from measurements of the round-trip times of flight of laser pulses along known directions. These instruments could also provide information on characteristics of targets, including roughnesses and reflectivities of surfaces and optical densities of such semi-solid objects as trees and clouds. Unlike in prior range-imaging instruments based on times of flight along known directions, there would be no moving parts; aiming of the laser beams along the known directions would not be accomplished by mechanical scanning of mirrors, prisms, or other optical components. Instead, aiming would be accomplished by using solid-state devices to switch input and output beams along different fiber-optic paths. Because of the lack of moving parts, these instruments could be extraordinarily reliable, rugged, and long-lasting. An instrument of this type would include an optical transmitter that would send out a laser pulse along a chosen direction to a target. An optical receiver coaligned with the transmitter would measure the temporally varying intensity of laser light reflected from the target to determine the distance and surface characteristics of the target. The transmitter would be a combination of devices for generating precise directional laser illumination. It would include a pulsed laser, the output of which would be coupled into a fiber-optic cable with a fan-out and solid-state optical switches that would enable switching of the laser beam onto one or more optical fibers terminated at known locations in an array on a face at the focal plane of a telescope. The array would be imaged by the telescope onto the target space. The receiver optical system could share the aforementioned telescope with the transmitter or could include a separate telescope aimed in the same direction as that of the transmitting telescope. In either case, light reflected from the target would be focused by the receiver optical system onto an array of optical fibers matching the array in the transmitter. These optical fibers would couple the received light to one or more photodetector( s). Optionally, the receiver could include solid-state optical switches for choosing which optical fiber(s) would couple light to the photodetector(s). This instrument architecture is flexible and can be optimized for a wide variety of applications and levels of performance. For example, it is scalable to any number of pixels and pixel resolutions and is compatible with a variety of ranging and photodetection methodologies, including, for example, ranging by use of modulated (including pulsed and encoded) light signals. The use of fixed arrays of optical fibers to generate controlled illumination patterns would eliminate the mechanical complexity and much of the bulk of optomechanical scanning assemblies. Furthermore, digital control of the selection of the fiber-optic pathways for the transmitted beams could afford capabilities not seen in previous three-dimensional range-imaging systems. Instruments of this type could be specialized for use as, for example, proximity detectors, three-dimensional robotic vision systems, airborne terrain-mapping systems, and inspection systems.
Author
RANGEFINDING; IMAGING TECHNIQUES; ROBOTICS; OPTICAL COMMUNICATION; PULSED LASERS; LUMINOUS INTENSITY; COMPUTER VISION; OPTICAL EQUIPMENT
20080048030 NASA Glenn Research Center, Cleveland, OH, United States
Predicting Properties of Unidirectional-Nanofiber Composites
Chamis, Christos C.; Handler, Louis M.; Manderscheid, Jane; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): LEW-18366-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3452
A theory for predicting mechanical, thermal, electrical, and other properties of unidirectional-nanofiber/matrix composite materials is based on the prior theory of micromechanics of composite materials. In the development of the present theory, the prior theory of micromechanics was extended, through progressive substructuring, to the level of detail of a nanoscale slice of a nanofiber. All the governing equations were then formulated at this level. The substructuring and the equations have been programmed in the ICAN/JAVA computer code, which was reported in "ICAN/JAVA: Integrated Composite Analyzer Recoded in Java" (LEW-17247), NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 36. In a demonstration, the theory as embodied in the computer code was applied to a graphite-nanofiber/epoxy laminate and used to predict 25 properties. Most of the properties were found to be distributed along the through-the-thickness direction. Matrix-dependent properties were found to have bimodal through-the-thickness distributions with discontinuous changes from mode to mode.
Author
COMPOSITE MATERIALS; NANOCOMPOSITES; PREDICTIONS; MATRIX MATERIALS; LAMINATES; JAVA (PROGRAMMING LANGUAGE); GRAPHITE-EPOXY COMPOSITES; COMPUTER PROGRAMS
20080048031 NASA Glenn Research Center, Cleveland, OH, United States
Logic Gates Made of N-Channel JFETs and Epitaxial Resistors
Krasowski, Michael J.; NASA Tech Briefs, December 2008; December 2008; pp. 13-1; In English; Original contains color illustrations
Report No.(s): LEW-18256-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3415
Prototype logic gates made of n-channel junction field-effect transistors (JFETs) and epitaxial resistors have been demonstrated, with a view toward eventual implementation of digital logic devices and systems in silicon carbide (SiC) integrated circuits (ICs). This development is intended to exploit the inherent ability of SiC electronic devices to function at temperatures from 300 to somewhat above 500 C and withstand large doses of ionizing radiation. SiC-based digital logic devices and systems could enable operation of sensors and robots in nuclear reactors, in jet engines, near hydrothermal vents, and in other environments that are so hot or radioactive as to cause conventional silicon electronic devices to fail. At present, current needs for digital processing at high temperatures exceed SiC integrated circuit production capabilities, which do not allow for highly integrated circuits. Only single to small number component production of depletion mode n-channel JFETs and epitaxial resistors on a single substrate is possible. As a consequence, the fine matching of components is impossible, resulting in rather large direct-current parameter distributions within a group of transistors typically spanning multiples of 5 to 10. Add to this the lack of p-channel devices to complement the n-channel FETs, the lack of precise dropping diodes, and the lack of enhancement mode devices at these elevated temperatures and the use of conventional direct coupled and buffered direct coupled logic gate design techniques is impossible. The presented logic gate design is tolerant of device parameter distributions and is not hampered by the lack of complementary devices or dropping diodes. In addition to n-channel JFETs, these gates include level-shifting and load resistors (see figure). Instead of relying on precise matching of parameters among individual JFETS, these designs rely on choosing the values of these resistors and of supply potentials so as to make the circuits perform the desired functions throughout the ranges over which the parameters of the JFETs are distributed. The supply rails V(sub dd) and V(sub ss) and the resistors R are chosen as functions of the distribution of direct-current operating parameters of the group of transistors used.
Author
LOGIC CIRCUITS; GATES (CIRCUITS); SEMICONDUCTOR DEVICES; JFET; RESISTORS; EPITAXY; ELECTRICAL RESISTIVITY
20080048032 NASA Glenn Research Center, Cleveland, OH, United States
SiC JFET Transistor Circuit Model for Extreme Temperature Range
Neudeck, Philip G.; NASA Tech Briefs, December 2008; December 2008; pp. 9-1; In English
Report No.(s): LEW-18342-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3418
A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation Program with Integrated Circuit Emphasis (SPICE) general-purpose analog-integrated-circuit-simulating software. NGSPICE in its unmodified form is used for simulating and designing circuits made from silicon-based transistors that operate at or near room temperature. Two rapid modifications of NGSPICE source code enable SiC JFETs to be simulated to 500 C using the well-known Level 1 model for silicon metal oxide semiconductor field-effect transistors (MOSFETs). First, the default value of the MOSFET surface potential must be changed. In the unmodified source code, this parameter has a value of 0.6, which corresponds to slightly more than half the bandgap of silicon. In NGSPICE modified to simulate SiC JFETs, this parameter is changed to a value of 1.6, corresponding to slightly more than half the bandgap of SiC. The second modification consists of changing the temperature dependence of MOSFET transconductance and saturation parameters. The unmodified NGSPICE source code implements a T(sup -1.5) temperature dependence for these parameters. In order to mimic the temperature behavior of experimental SiC JFETs, a T(sup -1.3) temperature dependence must be implemented in the NGSPICE source code. Following these two simple modifications, the Level 1 MOSFET model of the NGSPICE circuit simulation program reasonably approximates the measured high-temperature behavior of experimental SiC JFETs properly operated with zero or reverse bias applied to the gate terminal. Modification of additional silicon parameters in the NGSPICE source code was not necessary to model experimental SiC JFET current-voltage performance across the entire temperature range from 25 to 500 C.
Author
JFET; SILICON CARBIDES; TRANSISTOR CIRCUITS; INTEGRATED CIRCUITS; THERMAL RESISTANCE; COMPUTERIZED SIMULATION
20080048033 California Inst. of Tech., Pasadena, CA, United States
Ka-Band Transponder for Deep-Space Radio Science
Dennis, Matthew S.; Mysoor, Narayan R.; Folkner, William M.; Mendoza, Ricardo; Venkatesan, Jaikrishna; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): NPO-46698; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3459
A one-page document describes a Ka-band transponder being developed for use in deep-space radio science. The transponder receives in the Deep Space Network (DSN) uplink frequency band of 34.2 to 34.7 GHz, transmits in the 31.8- to 32.3 GHz DSN downlink band, and performs regenerative ranging on a DSN standard 4-MHz ranging tone subcarrier phase-modulated onto the uplink carrier signal. A primary consideration in this development is reduction in size, relative to other such transponders. The transponder design is all-analog, chosen to minimize not only the size but also the number of parts and the design time and, thus, the cost. The receiver features two stages of frequency down-conversion. The receiver locks onto the uplink carrier signal. The exciter signal for the transmitter is derived from the same source as that used to generate the first-stage local-oscillator signal. The ranging-tone subcarrier is down-converted along with the carrier to the second intermediate frequency, where the 4-MHz tone is demodulated from the composite signal and fed into a ranging-tone-tracking loop, which regenerates the tone. The regenerated tone is linearly phase-modulated onto the downlink carrier.
Author
TRANSPONDERS; RANGEFINDING; UPLINKING; INTERMEDIATE FREQUENCIES; CARRIER FREQUENCIES; DOWN-CONVERTERS; PHASE MODULATION
20080048034 California Inst. of Tech., Pasadena, CA, United States
Reducing Surface Clutter in Cloud Profiling Radar Data
Tanelli, Simone; Pak, Kyung; Durden, Stephen; Im, Eastwood; NASA Tech Briefs, December 2008; December 2008; pp. 6-; In English
Report No.(s): NPO-44873; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3414
An algorithm has been devised to reduce ground clutter in the data products of the CloudSat Cloud Profiling Radar (CPR), which is a nadir-looking radar instrument, in orbit around the Earth, that measures power backscattered by clouds as a function of distance from the instrument. Ground clutter contaminates the CPR data in the lowest 1 km of the atmospheric profile, heretofore making it impossible to use CPR data to satisfy the scientific interest in studying clouds and light rainfall at low altitude. The algorithm is based partly on the fact that the CloudSat orbit is such that the geodetic altitude of the CPR varies continuously over a range of approximately 25 km. As the geodetic altitude changes, the radar timing parameters are changed at intervals defined by flight software in order to keep the troposphere inside a data-collection time window. However, within each interval, the surface of the Earth continuously "scans through" (that is, it moves across) a few range bins of the data time window. For each radar profile, only few samples [one for every range-bin increment ((Delta)r = 240 m)] of the surface-clutter signature are available around the range bin in which the peak of surface return is observed, but samples in consecutive radar profiles are offset slightly (by amounts much less than (Delta)r) with respect to each other according to the relative change in geodetic altitude. As a consequence, in a case in which the surface area under examination is homogenous (e.g., an ocean surface), a sequence of consecutive radar profiles of the surface in that area contains samples of the surface response with range resolution (Delta)p much finer than the range-bin increment ((Delta)p << r). Once the high-resolution surface response has thus become available, the profile of surface clutter can be accurately estimated by use of a conventional maximum-correlation scheme: A translated and scaled version of the high-resolution surface response is fitted to the observed low-resolution profile. The translation and scaling factors that optimize the fit in a maximum-correlation sense represent (1) the true position of the surface relative to the sampled surface peak and (2) the magnitude of the surface backscatter. The performance of this algorithm has been tested on CloudSat data acquired over an ocean surface. A preliminary analysis of the test data showed a surface-clutter-rejection ratio over flat surfaces of >10 dB and a reduction of the contaminated altitude over ocean from about 1 km to about 0.5 km (over the ocean). The algorithm has been embedded in CloudSat L1B processing as of Release 04 (July 2007), and the estimated flat surface clutter is removed in L2B-GEOPROF product from the observed profile of reflectivity (see CloudSat product documentation for details and performance at http://www.cloudsat.cira.colostate.edu/ dataSpecs.php?prodid=1).
Author
CLUTTER; NOISE REDUCTION; CLOUDSAT; APPLICATIONS PROGRAMS (COMPUTERS); RADAR DATA
20080048035 United Space Alliance, Houston, TX, United States
Replication of Space-Shuttle Computers in FPGAs and ASICs
Ferguson, Roscoe C.; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-24141-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3460
A document discusses the replication of the functionality of the onboard space-shuttle general-purpose computers (GPCs) in field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). The purpose of the replication effort is to enable utilization of proven space-shuttle flight software and software-development facilities to the extent possible during development of software for flight computers for a new generation of launch vehicles derived from the space shuttles. The replication involves specifying the instruction set of the central processing unit and the input/output processor (IOP) of the space-shuttle GPC in a hardware description language (HDL). The HDL is synthesized to form a "core" processor in an FPGA or, less preferably, in an ASIC. The core processor can be used to create a flight-control card to be inserted into a new avionics computer. The IOP of the GPC as implemented in the core processor could be designed to support data-bus protocols other than that of a multiplexer interface adapter (MIA) used in the space shuttle. Hence, a computer containing the core processor could be tailored to communicate via the space-shuttle GPC bus and/or one or more other buses.
Author
FIELD-PROGRAMMABLE GATE ARRAYS; AIRBORNE/SPACEBORNE COMPUTERS; APPLICATION SPECIFIC INTEGRATED CIRCUITS; APPLICATIONS PROGRAMS (COMPUTERS); CHANNELS (DATA TRANSMISSION); COMPUTER PROGRAMS
20080048036 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Demisable Reaction-Wheel Assembly
Roder, Russell; Ahronovich, Eliezer; Davis, Milton C., III; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): GSC-14845-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3461
A document discusses the concept of a demisable motor-drive-and-flywheel assembly [reaction-wheel assembly (RWA)] used in controlling the attitude of a spacecraft. Demisable as used here does not have its traditional legal meaning; instead, it signifies susceptible to melting, vaporizing, and/or otherwise disintegrating during re-entry of the spacecraft into the atmosphere of the Earth so as not to pose a hazard to anyone or anything on the ground. Prior RWAs include parts made of metals (e.g., iron, steel, and titanium) that melt at high temperatures and include structures of generally closed character that shield some parts (e.g., magnets) against re-entry heating. In a demisable RWA, the flywheel would be made of aluminum, which melts at a lower temperature. The flywheel web would not be a solid disk but would have a more open, nearly-spoke-like structure so that it would disintegrate more rapidly; hence, the flywheel rim would separate more rapidly so that parts shielded by the rim would be exposed sooner to re-entry heating. In addition, clearances between the flywheel and other components would be made greater, imparting a more open character and thus increasing the exposure of those components.
Author
AERODYNAMIC HEATING; ATTITUDE (INCLINATION); FLYWHEELS; REACTION WHEELS; MELTING; VAPORIZING; DISINTEGRATION; REENTRY EFFECTS; ALUMINUM
20080048037 NASA Goddard Space Flight Center, Greenbelt, MD, United States
HDF-EOS Web Server
Ullman, Richard; Bane, Bob; Yang, Jingli; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-15011-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3439
A shell script has been written as a means of automatically making HDF-EOS-formatted data sets available via the World Wide Web. ("HDF-EOS" and variants thereof are defined in the first of the two immediately preceding articles.) The shell script chains together some software tools developed by the Data Usability Group at Goddard Space Flight Center to perform the following actions: Extract metadata in Object Definition Language (ODL) from an HDF-EOS file, Convert the metadata from ODL to Extensible Markup Language (XML), Reformat the XML metadata into human-readable Hypertext Markup Language (HTML), Publish the HTML metadata and the original HDF-EOS file to a Web server and an Open-source Project for a Network Data Access Protocol (OPeN-DAP) server computer, and Reformat the XML metadata and submit the resulting file to the EOS Clearinghouse, which is a Web-based metadata clearinghouse that facilitates searching for, and exchange of, Earth-Science data.
Author
HIERARCHIES; WORLD WIDE WEB; METADATA; EARTH SCIENCES; COMMUNICATION NETWORKS; DOCUMENT MARKUP LANGUAGES; HYPERTEXT
20080048038 NASA Goddard Space Flight Center, Greenbelt, MD, United States
HDF-EOS 5 Validator
Ullman, Richard; Bane, Bob; Yang, Jingli; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-15015-1; Copyright; Avail.: CASI: A01, Hardcopy
A computer program partly automates the task of determining whether an HDF-EOS 5 file is valid in that it conforms to specifications for such characteristics as attribute names, dimensionality of data products, and ranges of legal data values. ["HDF-EOS" and variants thereof are defined in "Converting EOS Data From HDF-EOS to netCDF" (GSC-15007-1), which is the first of several preceding articles in this issue of NASA Tech Briefs.] Previously, validity of a file was determined in a tedious and error-prone process in which a person examined human-readable dumps of data-file-format information. The present software helps a user to encode the specifications for an HDFEOS 5 file, and then inspects the file for conformity with the specifications: First, the user writes the specifications in Extensible Markup Language (XML) by use of a document type definition (DTD) that is part of the program. Next, the portion of the program (denoted the validator) that performs the inspection is executed, using, as inputs, the specifications in XML and the HDF-EOS 5 file to be validated. Finally, the user examines the output of the validator.
Author
DOCUMENT MARKUP LANGUAGES; COMPUTER PROGRAMS; ERRORS; FORMAT; SPECIFICATIONS
20080048039 TDA Research, Inc., Wheat Ridge, CO, United States; TDA Research, Inc., Wheat Ridge, CO, United States
System for Removing Pollutants from Incinerator Exhaust
Wickham, David t.; Bahr, James; Dubovik, Rita; Gebhard, Steven C.; Lind, Jeffrey; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): MSC-23440-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3427
A system for removing pollutants -- primarily sulfur dioxide and mixed oxides of nitrogen (NOx) -- from incinerator exhaust has been demonstrated. The system is also designed secondarily to remove particles, hydrocarbons, and CO. The system is intended for use in an enclosed environment, for which a prior NOx-and-SO2-removal system designed for industrial settings would not be suitable.
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EXHAUST SYSTEMS; NITROGEN OXIDES; SULFUR DIOXIDES; INCINERATORS; EXHAUST GASES; COMBUSTION CHEMISTRY; POLLUTION CONTROL
20080048040 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Simulating Attitudes and Trajectories of Multiple Spacecraft
Stoneking, Eric; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-14817-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3444
A computer program called "42" simulates the attitudes and trajectories of multiple spacecraft flying in formation anywhere in the Solar System.
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COMPUTER PROGRAMS; FORMATION FLYING; SIMULATION; SPACECRAFT TRAJECTORIES; SATELLITE CONSTELLATIONS; SPACECRAFT CONTROL; SPACECRAFT GUIDANCE
20080048041 TPL, Inc., Albuquerque, NM, United States
Oxide Fiber Cathode Materials for Rechargeable Lithium Cells
Rice, Catherine E.; Welker, Mark F.; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-22892-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3448
LiCoO2 and LiNiO2 fibers have been investigated as alternatives to LiCoO2 and LiNiO2 powders used as lithium-intercalation compounds in cathodes of rechargeable lithium-ion electrochemical cells. In making such a cathode, LiCoO2 or LiNiO2 powder is mixed with a binder [e.g., poly(vinylidene fluoride)] and an electrically conductive additive (usually carbon) and the mixture is pressed to form a disk. The binder and conductive additive contribute weight and volume, reducing the specific energy and energy density, respectively. In contrast, LiCoO2 or LiNiO2 fibers can be pressed and sintered to form a cathode, without need for a binder or a conductive additive. The inter-grain contacts of the fibers are stronger and have fewer defects than do those of powder particles. These characteristics translate to increased flexibility and greater resilience on cycling and, consequently, to reduced loss of capacity from cycle to cycle. Moreover, in comparison with a powder-based cathode, a fiber-based cathode is expected to exhibit significantly greater ionic and electronic conduction along the axes of the fibers. Results of preliminary charge/discharge-cycling tests suggest that energy densities of LiCoO2- and LiNiO2-fiber cathodes are approximately double those of the corresponding powder-based cathodes.
Author
OXIDES; CATHODES; LITHIUM; ELECTROCHEMICAL CELLS; RECHARGING
20080048042 Foster-Miller Associates, Inc., MA, United States
Crew Activity Analyzer
Murray, James; Kirillov, Alexander; NASA Tech Briefs, December 2008; December 2008; pp. 5-; In English; Original contains color illustrations
Report No.(s): ARC-15162-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3410
The crew activity analyzer (CAA) is a system of electronic hardware and software for automatically identifying patterns of group activity among crew members working together in an office, cockpit, workshop, laboratory, or other enclosed space. The CAA synchronously records multiple streams of data from digital video cameras, wireless microphones, and position sensors, then plays back and processes the data to identify activity patterns specified by human analysts. The processing greatly reduces the amount of time that the analysts must spend in examining large amounts of data, enabling the analysts to concentrate on subsets of data that represent activities of interest. The CAA has potential for use in a variety of governmental and commercial applications, including planning for crews for future long space flights, designing facilities wherein humans must work in proximity for long times, improving crew training and measuring crew performance in military settings, human-factors and safety assessment, development of team procedures, and behavioral and ethnographic research. The data-acquisition hardware of the CAA (see figure) includes two video cameras: an overhead one aimed upward at a paraboloidal mirror on the ceiling and one mounted on a wall aimed in a downward slant toward the crew area. As many as four wireless microphones can be worn by crew members. The audio signals received from the microphones are digitized, then compressed in preparation for storage. Approximate locations of as many as four crew members are measured by use of a Cricket indoor location system. [The Cricket indoor location system includes ultrasonic/radio beacon and listener units. A Cricket beacon (in this case, worn by a crew member) simultaneously transmits a pulse of ultrasound and a radio signal that contains identifying information. Each Cricket listener unit measures the difference between the times of reception of the ultrasound and radio signals from an identified beacon. Assuming essentially instantaneous propagation of the radio signal, the distance between that beacon and the listener unit is estimated from this time difference and the speed of sound in air.] In this system, six Cricket listener units are mounted in various positions on the ceiling, and as many as four Cricket beacons are attached to crew members. The three-dimensional position of each Cricket beacon can be estimated from the time-difference readings of that beacon from at least three Cricket listener units
Author
SPACECREWS; HUMAN FACTORS ENGINEERING; HUMAN PERFORMANCE; FLIGHT CREWS; COMPUTER PROGRAMS; DATA ACQUISITION; TIME RESPONSE; DIGITAL TELEVISION; MICROPHONES; AUDIO SIGNALS
20080048043 TenXys, Inc., Eagle, ID, United States
Distributing Data to Hand-Held Devices in a Wireless Network
Hodges, Mark; Simmons, Layne; NASA Tech Briefs, December 2008; December 2008; pp. ; In English
Report No.(s): MSC-23152-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3411
ADROIT is a developmental computer program for real-time distribution of complex data streams for display on Web-enabled, portable terminals held by members of an operational team of a spacecraft-command-and-control center who may be located away from the center. Examples of such terminals include personal data assistants, laptop computers, and cellular telephones. ADROIT would make it unnecessary to equip each terminal with platform- specific software for access to the data streams or with software that implements the information-sharing protocol used to deliver telemetry data to clients in the center. ADROIT is a combination of middleware plus software specific to the center. (Middleware enables one application program to communicate with another by performing such functions as conversion, translation, consolidation, and/or integration.) ADROIT translates a data stream (voice, video, or alphanumerical data) from the center into Extensible Markup Language, effectuates a subscription process to determine who gets what data when, and presents the data to each user in real time. Thus, ADROIT is expected to enable distribution of operations and to reduce the cost of operations by reducing the number of persons required to be in the center.
Author
APPLICATIONS PROGRAMS (COMPUTERS); DATA FLOW ANALYSIS; DOCUMENT MARKUP LANGUAGES; REAL TIME OPERATION; COMPUTER PROGRAMS; COMMAND AND CONTROL; SPACECRAFT CONTROL
20080048044 Creare, Inc., Hanover, NH, United States
Deployable Crew Quarters
Izenson, Michael G.; Chen, Weibo; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-23132-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3453
The deployable crew quarters (DCQ) have been designed for the International Space Station (ISS). Each DCQ would be a relatively inexpensive, deployable boxlike structure that is designed to fit in a rack bay. It is to be occupied by one crewmember to provide privacy and sleeping functions for the crew. A DCQ comprises mostly hard panels, made of a lightweight honeycomb or matrix/fiber material, attached to each other by cloth hinges. Both faces of each panel are covered with a layer of Nomex cloth and noise-suppression material to provide noise isolation from ISS. On Earth, the unit is folded flat and attached to a rigid pallet for transport to the ISS. On the ISS, crewmembers unfold the unit and install it in place, attaching it to ISS structural members by use of soft cords (which also help to isolate noise and vibration). A few hard pieces of equipment (principally, a ventilator and a smoke detector) are shipped separately and installed in the DCQ unit by use of a system of holes, slots, and quarter-turn fasteners. Full-scale tests showed that the time required to install a DCQ unit amounts to tens of minutes. The basic DCQ design could be adapted to terrestrial applications to satisfy requirements for rapid deployable emergency shelters that would be lightweight, portable, and quickly erected. The Temporary Early Sleep Station (TeSS) currently on-orbit is a spin-off of the DCQ.
Author
SPACECRAFT CABINS; HONEYCOMB STRUCTURES; CREWS; INTERNATIONAL SPACE STATION; STRUCTURAL MEMBERS; MATRIX MATERIALS
20080048045 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Spatial and Temporal Low-Dimensional Models for Fluid Flow
Kalb, Virginia; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): GSC-15130-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3462
A document discusses work that obtains a low-dimensional model that captures both temporal and spatial flow by constructing spatial and temporal four-mode models for two classic flow problems. The models are based on the proper orthogonal decomposition at two reference Reynolds numbers. Model predictions are made at an intermediate Reynolds number and compared with direct numerical simulation results at the new Reynolds number.
Author
DIRECT NUMERICAL SIMULATION; FLUID FLOW; DECOMPOSITION
20080048046 Boeing Co., Houston, TX, United States
Reducing Liquid Loss during Ullage Venting in Microgravity
Nguyen, Bich; Nguyen, Lauren; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-23230-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3457
A centripetal-force-based liquid/gas separator has been proposed as a means of reducing the loss of liquid during venting of the ullage of a tank in microgravity as a new supply of liquid is pumped into the tank. Centripetal-force-based liquid/gas separators are used on Earth, where mechanical drives (e.g., pumps and spinners) are used to impart flow speeds sufficient to generate centripetal forces large enough to effect separation of liquids from gases. For the proposed application, the separator would be designed so that there would be no need for such a pump because the tank-pressure-induced outflow speed during venting of the ullage would be sufficient for centripetal separation. A relatively small pump would be used, not for separation, but for returning the liquid recovered by the separator to the tank.
Author
CENTRIPETAL FORCE; SEPARATORS; STORAGE TANKS; SPACECRAFT DESIGN; VENTING; ULLAGE; MICROGRAVITY
20080048047 California Inst. of Tech., Pasadena, CA, United States
FPGA Coprocessor for Accelerated Classification of Images
Pingree, Paula J.; Scharenbroich, Lucas J.; Werne, Thomas A.; NASA Tech Briefs, December 2008; December 2008; pp. ; In English
Report No.(s): NPO-45961; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3417
An effort related to that described in the preceding article focuses on developing a spaceborne processing platform for fast and accurate onboard classification of image data, a critical part of modern satellite image processing. The approach again has been to exploit the versatility of recently developed hybrid Virtex-4FX field-programmable gate array (FPGA) to run diverse science applications on embedded processors while taking advantage of the reconfigurable hardware resources of the FPGAs. In this case, the FPGA serves as a coprocessor that implements legacy C-language support-vector-machine (SVM) image-classification algorithms to detect and identify natural phenomena such as flooding, volcanic eruptions, and sea-ice break-up. The FPGA provides hardware acceleration for increased onboard processing capability than previously demonstrated in software. The original C-language program demonstrated on an imaging instrument aboard the Earth Observing-1 (EO-1) satellite implements a linear-kernel SVM algorithm for classifying parts of the images as snow, water, ice, land, or cloud or unclassified. Current onboard processors, such as on EO-1, have limited computing power, extremely limited active storage capability and are no longer considered state-of-the-art. Using commercially available software that translates C-language programs into hardware description language (HDL) files, the legacy C-language program, and two newly formulated programs for a more capable expanded-linear-kernel and a more accurate polynomial-kernel SVM algorithm, have been implemented in the Virtex-4FX FPGA. In tests, the FPGA implementations have exhibited significant speedups over conventional software implementations running on general-purpose hardware.
Author
FIELD-PROGRAMMABLE GATE ARRAYS; ONBOARD DATA PROCESSING; IMAGE CLASSIFICATION; IMAGE PROCESSING; SATELLITE IMAGERY
20080048048 DR Technologies, Inc., San Diego, CA, United States
Electromagnetically Clean Solar Arrays
Stem, Theodore G.; Kenniston, Anthony E.; NASA Tech Briefs, December 2008; December 2008; pp. 12-1; In English
Report No.(s): LEW-18156-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3425
The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the wiring on the back of the panel. Each step increases the potential for occurrence of latent defects, loss of process control, and attrition of components. An EMCSA panel includes an integral cover made from a transparent material. The silicone cover supplants the individual cover glasses on the cells and serves as an additional unitary structural support that offers the advantage, relative to glass, of the robust, forgiving nature of the silcone material. The cover contains pockets that hold the solar cells in place during the lamination process. The cover is coated with indium tin oxide to make its surface electrically conductive, so that it serves as a contiguous, electrically grounded shield over the entire panel surface. The cells are mounted in proximity to metallic printed wiring. The painted-wiring layer comprises metal-film traces on a sheet of Kapton (or equivalent) polyimide. The traces include contact pads on one side of the sheet for interconnecting the cells. Return leads are on the opposite side of the sheet, positioned to form the return currents substantially as mirror images of, and in proximity to, the cell sheet currents, thereby minimizing magnetic moments. The printed-wiring arrangement mimics the back-wiring arrangement of conventional solar arrays, but the current-loop areas and the resulting magnetic moments are much smaller because the return-current paths are much closer to the solar-cell sheet currents. The contact pads are prepared with solder fo electrical and mechanical bonding to the cells. The pocketed cover/shield, the solar cells, the printed-wiring layer, an electrical bonding agent, a mechanical-bonding agent, a composite structural front-side face sheet, an aluminum honeycomb core, and a composite back-side face sheet are all assembled, then contact pads are soldered to the cells and the agents are cured in a single lamination process.
Author
PHOTOVOLTAIC CELLS; SOLAR ARRAYS; PANELS; ELECTROMAGNETIC INTERFERENCE; ELECTROMAGNETIC SHIELDING
20080048049 California Inst. of Tech., Pasadena, CA, United States
Spaceborne Hybrid-FPGA System for Processing FTIR Data
Bekker, Dmitriy; Blavier, Jean-Francois L.; Pingree, Paula J.; Lukowiak, Marcin; Shaaban, Muhammad; NASA Tech Briefs, December 2008; December 2008; pp. ; In English
Report No.(s): NPO-45957; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3416
Progress has been made in a continuing effort to develop a spaceborne computer system for processing readout data from a Fourier-transform infrared (FTIR) spectrometer to reduce the volume of data transmitted to Earth. The approach followed in this effort, oriented toward reducing design time and reducing the size and weight of the spectrometer electronics, has been to exploit the versatility of recently developed hybrid field-programmable gate arrays (FPGAs) to run diverse software on embedded processors while also taking advantage of the reconfigurable hardware resources of the FPGAs.
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FIELD-PROGRAMMABLE GATE ARRAYS; INFRARED SPECTROMETERS; DATA SYSTEMS; AIRBORNE/SPACEBORNE COMPUTERS; SPACECRAFT ELECTRONIC EQUIPMENT
20080048050 NASA Goddard Space Flight Center, Greenbelt, MD, United States
XML DTD and Schemas for HDF-EOS
Ullman, Richard; Yang, Jingli; NASA Tech Briefs, December 2008; December 2008; pp. 17-1; In English
Report No.(s): GSC-15016-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3442
An Extensible Markup Language (XML) document type definition (DTD) standard for the structure and contents of HDF-EOS files and their contents, and an equivalent standard in the form of schemas, have been developed.
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DOCUMENT MARKUP LANGUAGES; EARTH OBSERVING SYSTEM (EOS); DATA STRUCTURES
20080048051 Mississippi State Univ., Bay Saint Louis, MS, United States
MODIS Atmospheric Data Handler
Anantharaj, Valentine; Fitzpatrick, Patrick; NASA Tech Briefs, December 2008; December 2008; pp. ; In English
Report No.(s): SSC-00267; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3413
The Moderate Resolution Imaging Spectroradiometer (MODIS) Atmosphere Data Handler software converts the HDF data to ASCII format, and outputs: (1) atmospheric profiles of temperature and dew point and (2) total precipitable water. Quality-control data are also considered in the export procedure.
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IMAGING SPECTROMETERS; MODIS (RADIOMETRY); COMPUTER PROGRAMMING; DATA CONVERSION ROUTINES
20080048052 Miga Motor Company, Berkeley, CA, United States
Miniature High-Force, Long-Stroke SMA Linear Actuators
Cummin, Mark A.; Donakowski, William; Cohen, Howard; NASA Tech Briefs, December 2008; December 2008; pp. 23-2; In English
Report No.(s): LEW-18267-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3456
Improved long-stroke shape-memory-alloy (SMA) linear actuators are being developed to exert significantly higher forces and operate at higher activation temperatures than do prior SMA actuators. In these actuators, long linear strokes are achieved through the principle of displacement multiplication, according to which there are multiple stages, each intermediate stage being connected by straight SMA wire segments to the next stage so that relative motions of stages are additive toward the final stage, which is the output stage. Prior SMA actuators typically include polymer housings or shells, steel or aluminum stages, and polymer pads between successive stages of displacement-multiplication assemblies. Typical output forces of prior SMA actuators range from 10 to 20 N, and typical strokes range from 0.5 to 1.5 cm. An important disadvantage of prior SMA wire actuators is relatively low cycle speed, which is related to actuation temperature as follows: The SMA wires in prior SMA actuators are typically made of a durable nickel/titanium alloy that has a shape-memory activation temperature of 80 C. An SMA wire can be heated quickly from below to above its activation temperature to obtain a stroke in one direction, but must then be allowed to cool to somewhat below its activation temperature (typically, less than or equal to 60 C in the case of an activation temperature of 80 C) to obtain a stroke in the opposite direction (return stroke). At typical ambient temperatures, cooling times are of the order of several seconds. Cooling times thus limit cycle speeds. Wires made of SMA alloys having significantly higher activation temperatures [denoted ultra-high-temperature (UHT) SMA alloys] cool to the required lower return-stroke temperatures more rapidly, making it possible to increase cycle speeds. The present development is motivated by a need, in some applications (especially aeronautical and space-flight applications) for SMA actuators that exert higher forces, operate at greater cycle speeds, and have stronger housings that can withstand greater externally applied forces and impacts. The main novel features of the improved SMA actuators are the following: 1) The ends of the wires are anchored in compact crimps made from short steel tubes. Each wire end is inserted in a tube, the tube is flattened between planar jaws to make the tube grip the wire, the tube is compressed to a slight U-cross-section deformation to strengthen the grip, then the crimp is welded onto one of the actuator stages. The pull strength of a typical crimp is about 125 N -- comparable to the strength of the SMA wire and greater than the typical pull strengths of wire-end anchors in prior SMA actuators. Greater pull strength is one of the keys to achievement of higher actuation force; 2) For greater strength and resistance to impacts, housings are milled from aluminum instead of being made from polymers. Each housing is made from two pieces in a clamshell configuration. The pieces are anodized to reduce sliding friction; 3) Stages are made stronger (to bear greater compression loads without excessive flexing) by making them from steel sheets thicker than those used in prior SMA actuators. The stages contain recessed pockets to accommodate the crimps. Recessing the pockets helps to keep overall dimensions as small as possible; and, 4) UHT SMA wires are used to satisfy the higher-speed/higher-temperature requirement.
Author (revised)
SHAPE MEMORY ALLOYS; ACTUATORS; MECHANICAL PROPERTIES
20080048053 Boeing Co., Houston, TX, United States
'Bootstrap' Configuration for Multistage Pulse-Tube Coolers
Nguyen, Bich; Nguyen, Lauren; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-23500-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3455
A bootstrap configuration has been proposed for multistage pulse-tube coolers that, for instance, provide final-stage cooling to temperatures as low as 20 K. The bootstrap configuration supplants the conventional configuration, in which customarily the warm heat exchangers of all stages reject heat at ambient temperature. In the bootstrap configuration, the warm heat exchanger, the inertance tube, and the reservoir of each stage would be thermally anchored to the cold heat exchanger of the next warmer stage. The bootstrapped configuration is superior to the conventional setup, in some cases increasing the 20 K cooler's coefficient of performance two-fold over that of an otherwise equivalent conventional layout. The increased efficiency could translate into less power consumption, less cooler mass, and/or lower cost for a given amount of cooling.
Author
COOLERS; TEMPERATURE CONTROL; CONFIGURATIONS; THERMODYNAMICS
20080048054 California Inst. of Tech., Pasadena, CA, United States
Heterogeneous Superconducting Low-Noise Sensing Coils
Hahn, Inseob; Penanen, Konstantin I.; Ho Eom, Byeong; NASA Tech Briefs, December 2008; December 2008; pp. 21-2; In English; Original contains color illustrations
Report No.(s): LEW-18366-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3451
A heterogeneous material construction has been devised for sensing coils of superconducting quantum interference device (SQUID) magnetometers that are subject to a combination of requirements peculiar to some advanced applications, notably including low-field magnetic resonance imaging for medical diagnosis. The requirements in question are the following: The sensing coils must be large enough (in some cases having dimensions of as much as tens of centimeters) to afford adequate sensitivity; The sensing coils must be made electrically superconductive to eliminate Johnson noise (thermally induced noise proportional to electrical resistance); and Although the sensing coils must be cooled to below their superconducting- transition temperatures with sufficient cooling power to overcome moderate ambient radiative heat leakage, they must not be immersed in cryogenic liquid baths. For a given superconducting sensing coil, this combination of requirements can be satisfied by providing a sufficiently thermally conductive link between the coil and a cold source. However, the superconducting coil material is not suitable as such a link because electrically superconductive materials are typically poor thermal conductors. The heterogeneous material construction makes it possible to solve both the electrical- and thermal-conductivity problems. The basic idea is to construct the coil as a skeleton made of a highly thermally conductive material (typically, annealed copper), then coat the skeleton with an electrically superconductive alloy (typically, a lead-tin solder) [see figure]. In operation, the copper skeleton provides the required thermally conductive connection to the cold source, while the electrically superconductive coating material shields against Johnson noise that originates in the copper skeleton.
Author
SQUID (DETECTORS); LOW NOISE; SENSORS; COILS; HETEROGENEITY; MATERIALS SELECTION
20080048055 Foster-Miller Associates, Inc., Waltham, MA, United States
Progress toward Making Epoxy/Carbon-Nanotube Composites
Tiano, Thomas; Roylance, Margaret; Gassner, John; Kyle, William; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-23278-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3450
A modicum of progress has been made in an effort to exploit single-walled carbon nanotubes as fibers in epoxy-matrix/fiber composite materials. Two main obstacles to such use of carbon nanotubes are the following: (1) bare nanotubes are not soluble in epoxy resins and so they tend to agglomerate instead of becoming dispersed as desired; and (2) because of lack of affinity between nanotubes and epoxy matrices, there is insufficient transfer of mechanical loads between the nanotubes and the matrices. Part of the effort reported here was oriented toward (1) functionalization of single-walled carbon nanotubes with methyl methacrylate (MMA) to increase their dispersability in epoxy resins and increase transfer of mechanical loads and (2) ultrasonic dispersion of the functionalized nanotubes in tetrahydrofuran, which was used as an auxiliary solvent to aid in dispersing the functionalized nanotubes into a epoxy resin. In another part of this effort, poly(styrene sulfonic acid) was used as the dispersant and water as the auxiliary solvent. In one experiment, the strength of composite of epoxy with MMA-functionalized-nanotubes was found to be 29 percent greater than that of a similar composite of epoxy with the same proportion of untreated nanotubes.
Author
CARBON NANOTUBES; EPOXY MATRIX COMPOSITES; FABRICATION; NANOCOMPOSITES
20080048056 Eltron Research, Inc., United States
Electrocatalytic Reduction of Carbon Dioxide to Methane
Sammells, Anthony F.; Spiegel, Ella F.; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-23097-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3449
A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O yields CH4 + 2O2 has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally intended for use in a spacecraft life-support system, in which the methane would be vented to outer space. The process may also have potential utility in terrestrial applications in which either or both of the methane and oxygen produced might be utilized or vented to the atmosphere. A typical cell used to implement the process includes a polymer solid-electrolyte membrane, onto which are deposited cathode and anode films. The cathode film is catalytic for electrolytic reduction of CO2 at low overpotential. The anode film is typically made of platinum. When CO2 is circulated past the cathode, water is circulated past the anode, and a suitable potential is applied, the anode half-cell reaction is 4H2O yields 2O2 + 8H(+) + 8e(-). The H(+) ions travel through the membrane to the cathode, where they participate in the half-cell reaction CO2 + 8H(+) + 8e(-) yields CH4 + 2H2O.
Author
ELECTROCATALYSTS; CHEMICAL REACTIONS; REDUCTION (CHEMISTRY); CARBON DIOXIDE; METHANE; REACTION KINETICS; ELECTROCHEMISTRY
20080048057 California Inst. of Tech., Pasadena, CA, United States
Delivering Images for Mars Rover Science Planning
Edmonds, Karina; NASA Tech Briefs, December 2008; December 2008; pp. 18-1; In English
Report No.(s): NPO-45671; Copyright; Avail.: CASI: A01, Hardcopy
A methodology has been developed for delivering, via the Internet, images transmitted to Earth from cameras on the Mars Explorer Rovers, the Phoenix Mars Lander, the Mars Science Laboratory, and the Mars Reconnaissance Orbiter spacecraft. The images in question are used by geographically dispersed scientists and engineers in planning Rover scientific activities and Rover maneuvers pertinent thereto.
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MARS SURFACE; IMAGE PROCESSING; IMAGING TECHNIQUES; DATA TRANSFER (COMPUTERS); COMPUTER PROGRAMS; DATA TRANSMISSION
20080048058 Creare, Inc., Hanover, NH, United States
Nonventing, Regenerable, Lightweight Heat Absorber
Izenson, Michael G.; Chen, Weibo; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): MSC-23914-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3454
A lightweight, regenerable heat absorber (RHA), developed for rejecting metabolic heat from a space suit, may also be useful on Earth for short-term cooling of heavy protective garments. Unlike prior space-suit-cooling systems, a system that includes this RHA does not vent water. The closed system contains water reservoirs, tubes through which water is circulated to absorb heat, an evaporator, and an absorber/radiator. The radiator includes a solution of LiCl contained in a porous material in titanium tubes. The evaporator cools water that circulates through a liquid-cooled garment. Water vapor produced in the evaporator enters the radiator tubes where it is absorbed into the LiCl solution, releasing heat. Much of the heat of absorption is rejected to the environment via the radiator. After use, the RHA is regenerated by heating it to a temperature of 100 C for about 2 hours to drive the absorbed water back to the evaporator. A system including a prototype of the RHA was found to be capable of maintaining a temperature of 20 C while removing heat at a rate of 200 W for 6 hours.
Author
SPACE SUITS; EVAPORATORS; THERMAL ABSORPTION; COOLING SYSTEMS; LITHIUM CHLORIDES; REJECTION
20080048059 California Inst. of Tech., Pasadena, CA, United States
Multibeam Altimeter Navigation Update Using Faceted Shape Model
Bayard, David S.; Brugarolas, Paul; Broschart, Steve; NASA Tech Briefs, December 2008; December 2008; pp. 7-; In English; Original contains color illustrations
Report No.(s): NPO-44428; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3412
A method of incorporating information, acquired by a multibeam laser or radar altimeter system, pertaining to the distance and direction between the system and a nearby target body, into an estimate of the state of a vehicle upon which the system is mounted, involves the use of a faceted model to represent the shape of the target body. Fundamentally, what one seeks to measure is the distance from the vehicle to the target body.
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ALTIMETERS; NAVIGATION; OPTICAL RADAR; DISTANCE MEASURING EQUIPMENT; SPACECRAFT GUIDANCE; NAVIGATION AIDS
20080048060 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Specialized Color Function for Display of Signed Data
Kalb, Virginia; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-15128-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3446
This Mathematica script defines a color function to be used with Mathematica's plotting modules for differentiating data attaining both positive and negative values. Positive values are shown as shades of blue, and negative values are shown in red. The intensity of the color reflects the absolute value of the data value.
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COLOR; SHADES; PLOTTING; COMPUTER GRAPHICS; APPLICATIONS PROGRAMS (COMPUTERS)
20080048061 Science Systems and Applications, Inc., Greenbelt, MD, United States
Delivering Alert Messages to Members of a Work Force
Loftis, Julia; Nickens, Stephanie; Pell, Melissa; Pell, Vince; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-14927-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3447
Global Alert Resolution Network (GARNET) is a software system for delivering emergency alerts as well as less-urgent messages to members of the Goddard Space Flight Center work force via an intranet or the Internet, and can be adapted to similar use in other large organizations.
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COMPUTER NETWORKS; EMERGENCIES; INTERNETS; COMPUTER PROGRAMS
20080048062 Intelligent Automation Corp., United States
Radio Ranging System for Guidance of Approaching Spacecraft
Manikonda, Vikram; vanDoom, Eric; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): MSC-23474-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3422
A radio communication and ranging system has been proposed for determining the relative position and orientations of two approaching spacecraft to provide guidance for docking maneuvers. On Earth, the system could be used similarly for guiding approaching aircraft and for automated positioning of large, heavy objects. In principle, the basic idea is to (1) measure distances between radio transceivers on the two spacecraft and (2) compute the relative position and orientations from the measured distances.
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RADIO COMMUNICATION; RANGEFINDING; SPACECRAFT GUIDANCE; RENDEZVOUS GUIDANCE; DOCKING
20080048063 NASA Goddard Space Flight Center, Greenbelt, MD, United States
HDF-EOS 2 and HDF-EOS 5 Compatibility Library
Ullman, Richard; Bane, Bob; Yang, Jingli; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): GSC-15008-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3436
The HDF-EOS 2 and HDF-EOS 5 Compatibility Library contains C-language functions that provide uniform access to HDF-EOS 2 and HDF-EOS 5 files through one set of application programming interface (API) calls. ("HDFEOS 2" and "HDF-EOS 5" are defined in the immediately preceding article.) Without this library, differences between the APIs of HDF-EOS 2 and HDF-EOS 5 would necessitate writing of different programs to cover HDF-EOS 2 and HDF-EOS 5. The API associated with this library is denoted "he25." For nearly every HDF-EOS 5 API call, there is a corresponding he25 API call. If a file in question is in the HDF-EOS 5 format, the code reverts to the corresponding HDF-EOS 5 call; if the file is in the HDF-EOS 2 format, the code translates the arguments to HDF-EOS 2 equivalents (if necessary), calls the HDFEOS 2 call, and retranslates the results back to HDF-EOS 5 (if necessary).
Author
LIBRARIES; APPLICATION PROGRAMMING INTERFACE; C (PROGRAMMING LANGUAGE); COMPATIBILITY
20080048064 Hernandez Engineering, Inc., Houston, TX, United States
Improved Short-Circuit Protection for Power Cells in Series
Davies, Francis; NASA Tech Briefs, December 2008; December 2008; pp. 1; In English
Report No.(s): MSC-23446-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3423
A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply connected in a long series string to obtain a high voltage and a short circuit occurs, whichever short-circuit protection device trips first is exposed to nearly the full string voltage, which, typically, is large enough to damage the device. Depending on the specific cell design, the damage can defeat the protective function, cause a dangerous internal short circuit in the affected cell, and/or cascade to other cells. In the present scheme, reverse diodes rated at a suitably high current are connected across short series sub-strings, the lengths of which are chosen so that when a short-circuit protection device is tripped, the voltage across it does not exceed its rated voltage. This scheme preserves the resetting properties of the protective devices. It provides for bypassing of cells that fail open and limits cell reversal, though not as well as does the more-expensive scheme of connecting a diode across every cell.
Author
ELECTROCHEMICAL CELLS; SHORT CIRCUITS; CIRCUIT PROTECTION
20080048065 NASA, United States; Geological Survey, United States
Advanced Land Imager Assessment System
Chander, Gyanesh; Choate, Mike; Christopherson, Jon; Hollaren, Doug; Morfitt, Ron; Nelson, Jim; Nelson, Shar; Storey, James; Helder, Dennis; Ruggles, Tim; Kaita, Ed; Levy, Raviv; Ong, Lawrence; Markham, Brian; Schweiss, Robert; NASA Tech Briefs, December 2008; December 2008; pp. 2; In English
Report No.(s): GSC-15185-1; Copyright; Avail.: CASI: A01, Hardcopy
The Advanced Land Imager Assessment System (ALIAS) supports radiometric and geometric image processing for the Advanced Land Imager (ALI) instrument onboard NASA s Earth Observing-1 (EO-1) satellite. ALIAS consists of two processing subsystems for radiometric and geometric processing of the ALI s multispectral imagery. The radiometric processing subsystem characterizes and corrects, where possible, radiometric qualities including: coherent, impulse; and random noise; signal-to-noise ratios (SNRs); detector operability; gain; bias; saturation levels; striping and banding; and the stability of detector performance. The geometric processing subsystem and analysis capabilities support sensor alignment calibrations, sensor chip assembly (SCA)-to-SCA alignments and band-to-band alignment; and perform geodetic accuracy assessments, modulation transfer function (MTF) characterizations, and image-to-image characterizations. ALIAS also characterizes and corrects band-toband registration, and performs systematic precision and terrain correction of ALI images. This system can geometrically correct, and automatically mosaic, the SCA image strips into a seamless, map-projected image. This system provides a large database, which enables bulk trending for all ALI image data and significant instrument telemetry. Bulk trending consists of two functions: Housekeeping Processing and Bulk Radiometric Processing. The Housekeeping function pulls telemetry and temperature information from the instrument housekeeping files and writes this information to a database for trending. The Bulk Radiometric Processing function writes statistical information from the dark data acquired before and after the Earth imagery and the lamp data to the database for trending. This allows for multi-scene statistical analyses.
Author
IMAGE PROCESSING; GEODETIC ACCURACY; TERRAIN; STATISTICAL ANALYSIS; SIGNAL TO NOISE RATIOS; RADIOMETERS; MODULATION TRANSFER FUNCTION; EARTH OBSERVING SYSTEM (EOS)
20080048071 NASA Ames Research Center, Moffett Field, CA, United States
Rotorcraft Technology for HALE Aeroelastic Analysis
Young, Larry; Johnson, Wayne; September 10, 2008; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048071
Much of technology needed for analysis of HALE nonlinear aeroelastic problems is available from rotorcraft methodologies. Consequence of similarities in operating environment and aerodynamic surface configuration. Technology available - theory developed, validated by comparison with test data, incorporated into rotorcraft codes. High subsonic to transonic rotor speed, low to moderate Reynolds number. Structural and aerodynamic models for high aspect-ratio wings and propeller blades. Dynamic and aerodynamic interaction of wing/airframe and propellers. Large deflections, arbitrary planform. Steady state flight, maneuvers and response to turbulence. Linearized state space models. This technology has not been extensively applied to HALE configurations. Correlation with measured HALE performance and behavior required before can rely on tools.
Author
AERODYNAMIC CHARACTERISTICS; AEROELASTICITY; CONTROL SURFACES; LOW REYNOLDS NUMBER; PROPELLER BLADES; ROTARY WING AIRCRAFT; SUBSONIC SPEED; TURBULENCE; ROTOR SPEED
Additions to the NASA Aeronautics and Space Database as of 01/12/2009
20080048097 NASA Marshall Space Flight Center, Huntsville, AL, United States
Radiation from Relativistic Jets
Nishikawa, K.-I.; Mizuno, Y.; Hardee, P.; Sol, H.; Medvedev, M.; Zhang, B.; Nordlund, A.; Frederiksen, J. T.; Fishman, G. J.; Preece, R.; April 22, 2008; In English; Workshop on Blazar Variability Across the Electromagnetic Spectrum, 22-25 Aug. 2008, Palaiseau, France; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG05GK73G; NNX07AJ88G; NNX08AG83G; NNX07AJ50G; NNX08AL39G; NSF AST-0506719
Copyright; Avail.: CASI: A02, Hardcopy
Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electron-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the presence of relativistic jets, instabilities such as the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability create collisionless shocks, which are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons in small-scale magnetic fields has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation, a case of diffusive synchrotron radiation, may be important to understand the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.
Author
ASTROPHYSICS; NONTHERMAL RADIATION; RELATIVISTIC PLASMAS; PLASMA JETS; PLASMA PHYSICS; PARTICLE ACCELERATION; EMISSION SPECTRA
20080048098 NASA Marshall Space Flight Center, Huntsville, AL, United States
Operational Characteristics of a Low-Energy FARAD Thruster
Polzin, Kurt A.; Rose, M. Frank; Miller, Robert; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference/American Institute of Aeronautics and Astronautics, 20-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNM06AA17G
Report No.(s): AIAA Paper-2008-5011; Copyright; Avail.: CASI: A02, Hardcopy
Data from a 100 J per pulse electrodeless accelerator employing pulsed RF-preionization are presented to gain insight into the accelerator's operating characteristics. The data suggest that the propellant distribution is highly unoptimized, with most of the gas inaccessible to the discharge and the remainder mostly concentrated at the inner radius of the coil. The pulsed RF-preionization discharge produces a visible plasma, but like the gas distribution it mostly appears concentrated at the inner radius of the thruster. Magnetic field probes in the discharge point to a current sheet that is not magnetically impermeable. These data also exhibit signs of nonrepeatability, and time-integrated discharge photography shows signs of spatial nonuniformity in both the radial and azimuthal directions. Terminal voltage measurements on the two capacitor banks of the thruster do not exhibit the asymmetric nature (in time) typically associated with an efficient pulsed plasma accelerator. Based on the experimental evidence, the poor performance of the thruster is thought to be due to insufficient preionization, which at these low discharge energy levels severely limits the ability of the main current pulse to couple with and effectively accelerate the propellant.
Author
PLASMA ACCELERATORS; PERFORMANCE TESTS; TECHNOLOGY ASSESSMENT; RESEARCH AND DEVELOPMENT; ELECTRIC PROPULSION; SPACECRAFT PROPULSION
20080048103 NASA Marshall Space Flight Center, Huntsville, AL, United States
Preliminary Development and Testing of a Self-Injecting Gallium MPD Thruster
Thomas, Robert E.; Burton, Rodney L.; Polzin, Kurt A.; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Discharge current and terminal voltage measurements were performed on a gallium electromagnetic thruster at discharge currents in the range of 20-54 kA. It was found that the arc impedance has a value of 6-7 m(Omega) at peak current. The absence of high-frequency oscillations in the terminal voltage trace indicates lack of the "onset" condition often seen in MPD arcs, suggesting that a sufficient number of charge carriers are present for current conduction. The mass ablated per pulse was not measured experimentally; however the mass flow rate was calculated using an ion current assumption and an anode power balance. Measurement of arc impedance predicts a temperature of 3.5 eV which from Saha equilibrium corresponds to Z = 2.0 - 3.5, and assuming Z = 2 yields an Isp of 3000 s and thrust efficiency of 50%.
Author
GALLIUM; MASS FLOW RATE; MAGNETOPLASMADYNAMIC THRUSTERS; IMPEDANCE MEASUREMENT; ELECTRICAL MEASUREMENT; CHARGE CARRIERS
20080048109 NASA Marshall Space Flight Center, Huntsville, AL, United States
Validation of High-Fidelity CFD Simulations for Rocket Injector Design
Tucker, P. Kevin; Menon, Suresh; Merkle, Charles L.; Oefelein, Joseph C.; Yang, Vigor; July 21, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Computational fluid dynamics (CFD) has the potential to improve the historical rocket injector design process by evaluating the sensitivity of performance and injector-driven thermal environments to the details of the injector geometry and key operational parameters. Methodical verification and validation efforts on a range of coaxial injector elements have shown the current production CFD capability must be improved in order to quantitatively impact the injector design process. This paper documents the status of a focused effort to compare and understand the predictive capabilities and computational requirements of a range of CFD methodologies on a set of single element injector model problems. The steady Reynolds-Average Navier-Stokes (RANS), unsteady Reynolds-Average Navier-Stokes (URANS) and three different approaches using the Large Eddy Simulation (LES) technique were used to simulate the initial model problem, a single element coaxial injector using gaseous oxygen and gaseous hydrogen propellants. While one high-fidelity LES result matches the experimental combustion chamber wall heat flux very well, there is no monotonic convergence to the data with increasing computational tool fidelity. Systematic evaluation of key flow field regions such as the flame zone, the head end recirculation zone and the downstream near wall zone has shed significant, though as of yet incomplete, light on the complex, underlying causes for the performance level of each technique. 1 Aerospace Engineer and Combustion CFD Team Leader, MS ER42, NASA MSFC, AL 35812, Senior Member, AIAA. 2 Professor and Director, Computational Combustion Laboratory, School of Aerospace Engineering, 270 Ferst Dr., Atlanta, GA 30332, Associate Fellow, AIAA. 3 Reilly Professor of Engineering, School of Mechanical Engineering, 585 Purdue Mall, West Lafayette, IN 47907, Fellow, AIAA. 4 Principal Member of Technical Staff, Combustion Research Facility, 7011 East Avenue, MS9051, Livermore, CA 94550, Associate Fellow, AIAA. 5 J. L. and G. H. McCain Endowed Chair, Mechanical Engineering, 104 Research Building East, University Park, PA 16802, Fellow, AIAA. American Institute of Aeronautics and Astronautics 1
Author
COMPUTATIONAL FLUID DYNAMICS; LARGE EDDY SIMULATION; FLOW DISTRIBUTION; COMBUSTION CHAMBERS; AEROSPACE ENGINEERING; PROPELLANTS; NAVIER-STOKES EQUATION; INJECTORS
20080048125 NASA, Washington, DC, United States
NASA Tech Briefs, September 2008
September 2008; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A04, Hardcopy
Topics covered include: Nanotip Carpets as Antireflection Surfaces; Nano-Engineered Catalysts for Direct Methanol Fuel Cells; Capillography of Mats of Nanofibers; Directed Growth of Carbon Nanotubes Across Gaps; High-Voltage, Asymmetric-Waveform Generator; Magic-T Junction Using Microstrip/Slotline Transitions; On-Wafer Measurement of a Silicon-Based CMOS VCO at 324 GHz; Group-III Nitride Field Emitters; HEMT Amplifiers and Equipment for their On-Wafer Testing; Thermal Spray Formation of Polymer Coatings; Improved Gas Filling and Sealing of an HC-PCF; Making More-Complex Molecules Using Superthermal Atom/Molecule Collisions; Nematic Cells for Digital Light Deflection; Improved Silica Aerogel Composite Materials; Microgravity, Mesh-Crawling Legged Robots; Advanced Active-Magnetic-Bearing Thrust- Measurement System; Thermally Actuated Hydraulic Pumps; A New, Highly Improved Two-Cycle Engine; Flexible Structural-Health-Monitoring Sheets; Alignment Pins for Assembling and Disassembling Structures; Purifying Nucleic Acids from Samples of Extremely Low Biomass; Adjustable-Viewing-Angle Endoscopic Tool for Skull Base and Brain Surgery; UV-Resistant Non-Spore-Forming Bacteria From Spacecraft-Assembly Facilities; Hard-X-Ray/Soft-Gamma-Ray Imaging Sensor Assembly for Astronomy; Simplified Modeling of Oxidation of Hydrocarbons; Near-Field Spectroscopy with Nanoparticles Deposited by AFM; Light Collimator and Monitor for a Spectroradiometer; Hyperspectral Fluorescence and Reflectance Imaging Instrument; Improving the Optical Quality Factor of the WGM Resonator; Ultra-Stable Beacon Source for Laboratory Testing of Optical Tracking; Transmissive Diffractive Optical Element Solar Concentrators; Delaying Trains of Short Light Pulses in WGM Resonators; Toward Better Modeling of Supercritical Turbulent Mixing; JPEG 2000 Encoding with Perceptual Distortion Control; Intelligent Integrated Health Management for a System of Systems; Delay Banking for Managing Air Traffic; and Spline-Based Smoothing of Airfoil Curvatures.
Author
AEROGELS; ANTIREFLECTION COATINGS; BIOMASS; CARBON NANOTUBES; COMPOSITE MATERIALS; ELECTROCATALYSTS; GAMMA RAYS; HIGH ELECTRON MOBILITY TRANSISTORS; NANOSTRUCTURE GROWTH; MOLECULAR INTERACTIONS
20080048126 California Inst. of Tech., Pasadena, CA, United States
Simplified Modeling of Oxidation of Hydrocarbons
Bellan, Josette; Harstad, Kenneth; NASA Tech Briefs, September 2008; September 2008; pp. 29-3; In English; Original contains color illustrations
Report No.(s): NPO-44750; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3144
A method of simplified computational modeling of oxidation of hydrocarbons is undergoing development. This is one of several developments needed to enable accurate computational simulation of turbulent, chemically reacting flows. At present, accurate computational simulation of such flows is difficult or impossible in most cases because (1) the numbers of grid points needed for adequate spatial resolution of turbulent flows in realistically complex geometries are beyond the capabilities of typical supercomputers now in use and (2) the combustion of typical hydrocarbons proceeds through decomposition into hundreds of molecular species interacting through thousands of reactions. Hence, the combination of detailed reaction- rate models with the fundamental flow equations yields flow models that are computationally prohibitive. Hence, further, a reduction of at least an order of magnitude in the dimension of reaction kinetics is one of the prerequisites for feasibility of computational simulation of turbulent, chemically reacting flows. In the present method of simplified modeling, all molecular species involved in the oxidation of hydrocarbons are classified as either light or heavy; heavy molecules are those having 3 or more carbon atoms. The light molecules are not subject to meaningful decomposition, and the heavy molecules are considered to decompose into only 13 specified constituent radicals, a few of which are listed in the table. One constructs a reduced-order model, suitable for use in estimating the release of heat and the evolution of temperature in combustion, from a base comprising the 13 constituent radicals plus a total of 26 other species that include the light molecules and related light free radicals. Then rather than following all possible species through their reaction coordinates, one follows only the reduced set of reaction coordinates of the base. The behavior of the base was examined in test computational simulations of the combustion of heptane in a stirred reactor at various initial pressures ranging from 0.1 to 6 MPa. Most of the simulations were performed for stoichiometric mixtures; some were performed for fuel/oxygen mole ratios of 1/2 and 2.
Author
HYDROCARBONS; OXIDATION; MATHEMATICAL MODELS; TURBULENT FLOW; REACTION KINETICS; REACTING FLOW; MOLECULAR GASES
20080048127 California Inst. of Tech., Pasadena, CA, United States
Improved Gas Filling and Sealing of an HC-PCF
Poberezhskiy, Ilya; Meras, Patrick; Chang, Daniel; Spiers, Gary; NASA Tech Briefs, September 2008; September 2008; pp. 15-1; In English; Original contains color illustrations
Report No.(s): NPO-45193; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3116
An improved packaging approach has been devised for filling a hollow-core photonic-crystal fiber (HC-PCF) with a gas, sealing the HC-PCF to retain the gas, and providing for optical connections and, optionally, a plumbing fitting for changing or augmenting the gas filling. Gas-filled HC-PCFs can be many meters long and have been found to be attractive as relatively compact, lightweight, rugged alternatives to conventional gas-filled glass cells for use as molecular-resonance frequency references for stabilization of lasers in some optical-metrology, lidar, optical-communication, and other advanced applications. Prior approaches to gas filling and sealing of HC-PCFs have involved, variously, omission of any attempt to connectorize the PCF, connectorization inside a vacuum chamber (an awkward and expensive process), or temporary exposure of one end of an HC-PCF to the atmosphere, potentially resulting in contamination of the gas filling. Prior approaches have also involved, variously, fusion splicing of HC-PCFs with other optical fibers or other termination techniques that give rise to Fresnel reflections of about 4 percent, which results in output intensity noise.
Derived from text
OPTICAL FIBERS; SEALING; PHOTONICS; GAS FLOW; CRYSTALS; HERMETIC SEALS
20080048128 HyPerspectives, Bozeman, MT, United States
Processing LiDAR Data to Predict Natural Hazards
Fairweather, Ian; Crabtree, Robert; Hager, Stacey; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): SSC-00279; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3209
ELF-Base and ELF-Hazards (wherein 'ELF' signifies 'Extract LiDAR Features' and 'LiDAR' signifies 'light detection and ranging') are developmental software modules for processing remote-sensing LiDAR data to identify past natural hazards (principally, landslides) and predict future ones. ELF-Base processes raw LiDAR data, including LiDAR intensity data that are often ignored in other software, to create digital terrain models (DTMs) and digital feature models (DFMs) with sub-meter accuracy. ELF-Hazards fuses raw LiDAR data, data from multispectral and hyperspectral optical images, and DTMs and DFMs generated by ELF-Base to generate hazard risk maps. Advanced algorithms in these software modules include line-enhancement and edge-detection algorithms, surface-characterization algorithms, and algorithms that implement innovative data-fusion techniques. The line-extraction and edge-detection algorithms enable users to locate such features as faults and landslide headwall scarps. Also implemented in this software are improved methodologies for identification and mapping of past landslide events by use of (1) accurate, ELF-derived surface characterizations and (2) three LiDAR/optical-data-fusion techniques: post-classification data fusion, maximum-likelihood estimation modeling, and hierarchical within-class discrimination. This software is expected to enable faster, more accurate forecasting of natural hazards than has previously been possible.
Author
OPTICAL RADAR; COMPUTER PROGRAMS; WEATHER FORECASTING; REMOTE SENSING; DATA PROCESSING; MULTISENSOR FUSION
20080048129 West Virginia Univ., Morgantown, WV, United States; California Inst. of Tech., Pasadena, CA, United States
Estimating Software-Development Costs With Greater Accuracy
Baker, Dan; Hihn, Jairus; Lum, Karen; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English; Original contains color illustrations
Report No.(s): NPO-44858; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3212
COCOMOST is a computer program for use in estimating software development costs. The goal in the development of COCOMOST was to increase estimation accuracy in three ways: (1) develop a set of sensitivity software tools that return not only estimates of costs but also the estimation error; (2) using the sensitivity software tools, precisely define the quantities of data needed to adequately tune cost estimation models; and (3) build a repository of software-cost-estimation information that NASA managers can retrieve to improve the estimates of costs of developing software for their project. COCOMOST implements a methodology, called '2cee', in which a unique combination of well-known pre-existing data-mining and software-development- effort-estimation techniques are used to increase the accuracy of estimates. COCOMOST utilizes multiple models to analyze historical data pertaining to software-development projects and performs an exhaustive data-mining search over the space of model parameters to improve the performances of effort-estimation models. Thus, it is possible to both calibrate and generate estimates at the same time. COCOMOST is written in the C language for execution in the UNIX operating system.
Author
SOFTWARE ENGINEERING; COST ESTIMATES; COMPUTER PROGRAMS
20080048130 NASA Kennedy Space Center, Cocoa Beach, FL, United States
Alignment Pins for Assembling and Disassembling Structures
Campbell, Oliver C.; NASA Tech Briefs, September 2008; September 2008; pp. 24-2; In English; Original contains color and black and white illustrations
Report No.(s): KSC-12785; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3127
Simple, easy-to-use, highly effective tooling has been devised for maintaining alignment of bolt holes in mating structures during assembly and disassembly of the structures. The tooling was originally used during removal of a body flap from the space shuttle Atlantis, in which misalignments during removal of the last few bolts could cause the bolts to bind in their holes. By suitably modifying the dimensions of the tooling components, the basic design of the tooling can readily be adapted to other structures that must be maintained in alignment. The tooling includes tapered, internally threaded alignment pins designed to fit in the bolt holes in one of the mating structures, plus a draw bolt and a cup that are used to install or remove each alignment pin. In preparation for disassembly of two mating structures, external supports are provided to prevent unintended movement of the structures. During disassembly of the structures, as each bolt that joins the structures is removed, an alignment pin is installed in its place. Once all the bolts have been removed and replaced with pins, the pins maintain alignment as the structures are gently pushed or pulled apart on the supports. In assembling the two structures, one reverses the procedure described above: pins are installed in the bolt holes, the structures are pulled or pushed together on the supports, then the pins are removed and replaced with bolts. The figure depicts the tooling and its use. To install an alignment pin in a bolt hole in a structural panel, the tapered end of the pin is inserted from one side of the panel, the cup is placed over the pin on the opposite side of the panel, the draw bolt is inserted through the cup and threaded into the pin, the draw bolt is tightened to pull the pin until the pin is seated firmly in the hole, then the draw bolt and cup are removed, leaving the pin in place. To remove an alignment pin, the cup is placed over the pin on the first-mentioned side of the panel, the draw bolt is inserted through the cup and threaded into the pin, then the draw bolt is tightened to pull the pin out of the hole.
Author
MECHANICAL ENGINEERING; PINS; ALIGNMENT; ASSEMBLING
20080048131 California Inst. of Tech., Pasadena, CA, United States
Improving the Optical Quality Factor of the WGM Resonator
Savchenkov, Anatoliy; Matsko, Andrey; Iltchenko, Vladimir; NASA Tech Briefs, September 2008; September 2008; pp. 32-3; In English
Report No.(s): NPO-45053; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3161
Resonators usually are characterized with two partially dependent values: finesse (F) and quality factor (Q). The finesse of an empty Fabry-Perot (FP) resonator is defined solely by the quality of its mirrors and is calculated as F=piR(exp 1/2)/(1-R). The maximum up-to-date value of reflectivity R approximately equal to 1 - 1.6 x 10(exp -6) is achieved with dielectric mirrors. An FP resonator made with the mirrors has finesse F=1.9 x 10(exp 6). Further practical increase of the finesse of FP resonators is problematic because of the absorption and the scattering of light in the mirror material through fundamental limit on the reflection losses given by the internal material losses and by thermodynamic density fluctuations on the order of parts in 109. The quality factor of a resonator depends on both its finesse and its geometrical size. A one-dimensional FP resonator has Q=2 F L/lambda, where L is the distance between the mirrors and lambda is the wavelength. It is easy to see that the quality factor of the resonator is unlimited because L is unlimited. F and Q are equally important. In some cases, finesse is technically more valuable than the quality factor. For instance, buildup of the optical power inside the resonator, as well as the Purcell factor, is proportional to finesse. Sometimes, however, the quality factor is more valuable. For example, inverse threshold power of intracavity hyperparametric oscillation is proportional to Q(exp 2) and efficiency of parametric frequency mixing is proportional to Q(exp 3). Therefore, it is important to know both the maximally achievable finesse and quality factor values of a resonator. Whispering gallery mode (WGM) resonators are capable of achieving larger finesse compared to FP resonators. For instance, fused silica resonators with finesse 2.3 x 10(exp 6) and 2.8 x 10(exp 6) have been demonstrated. Crystalline WGM resonators reveal even larger finesse values, F=6.3 x 10(exp 6), because of low attenuation of light in the transparent optical crystals. The larger values of F and Q result in the enhancement of various nonlinear processes. Low-threshold Raman lasing, optomechanical oscillations, frequency doubling, and hyperparametric oscillations based on these resonators have been recently demonstrated. Theory predicts a possibility of nearly 10(exp 14) room-temperature optical Q-factors of optical crystalline WGM resonators, which correspond to finesse levels higher than 10(exp 9). Experiments have shown numbers a thousand times lower than that. The difference occurs due to media imperfections. To substantially reduce the optical losses caused by the imperfections, a specific, multi-step, asymptotic processing of the resonator is implemented. The technique has been initially developed to reduce microwave absorption in dielectric resonators. One step of the process consists of mechanical polishing performed after high temperature annealing. Several steps repeat one after another to lead to significant reduction in optical attenuation and, as a result, to the increase of Q-factor as well as finesse of the resonator which demonstrates a CaF2 WGM resonator with F greater than 10(exp 7) and Q greater than 10(exp 11).
Author
WHISPERING GALLERY MODES; OPTICAL RESONATORS; Q FACTORS
20080048132 Eloret Corp., CA, United States
Directed Growth of Carbon Nanotubes Across Gaps
Delzeit, Lance; Meyyapan, Meyya; NASA Tech Briefs, September 2008; September 2008; pp. ; In English; Original contains color and black and white illustrations
Report No.(s): ARC-14985-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3069
An experiment has shown that when single-walled carbon nanotubes (SWNTs) are grown by chemical vapor deposition in the presence of an electric field of suitable strength, the nanotubes become aligned along the electric field. In an important class of contemplated applications, one would exploit this finding in fabricating nanotube transistors; one would grow SWNTs across gaps between electrodes that would serve, subsequently, as source and drain contacts during operation of the transistors. In preparation for the experiment, a multilayer catalyst comprising a 20-nmthick underlayer of iridium (platinum group), a 1-nm-thick middle layer of iron, and a 0.2-nm-thick outer layer of molybdenum was ion-beam sputtered onto a quartz substrate. A 25 micrometers-diameter iron wire was used as a shadow mask during the sputtering to create a 25 micrometers gap in the catalyst. Then electrical leads were connected to the catalyst areas separated by the gap so that these catalyst areas would also serve as electrodes. The substrate as thus prepared was placed in a growth chamber that consisted of a quartz tube of 1-in. (2.54-cm) diameter enclosed in a furnace. SWNTs of acceptably high quantity and quality were grown in 10 minutes with methane at atmospheric pressure flowing through the chamber at a rate of 1,000 standard cubic centimeters per minute at a temperature of 900 C. To prevent oxidation of the SWNTs, the chamber was purged with 99.999-percent pure argon before and after growth, and the chamber was cooled to less than 300 C before opening it to the atmosphere after growth. When no voltage was applied across the gap, the SWNTs grew in random directions extending out from the edges of the catalyst at the gap. When a potential of 10 V was applied between the catalyst/electrode areas to create an electric field across the gap, the SWNTs grew across the gap, as shown in the figure.
Author
CARBON NANOTUBES; NANOSTRUCTURE GROWTH; GAPS; SEMICONDUCTORS (MATERIALS)
20080048133 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States
Testing of Error-Correcting Sparse Permutation Channel Codes
Shcheglov, Kirill, V.; Orlov, Sergei S.; NASA Tech Briefs, September 2008; September 2008; pp. 6; In English; Original contains color illustrations
Report No.(s): NPO-45196; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3215
A computer program performs Monte Carlo direct numerical simulations for testing sparse permutation channel codes, which offer strong error-correction capabilities at high code rates and are considered especially suitable for storage of digital data in holographic and volume memories. A word in a code of this type is characterized by, among other things, a sparseness parameter (M) and a fixed number (K) of 1 or "on" bits in a channel block length of N.
Derived from text
COMPUTER PROGRAMS; ERROR ANALYSIS; ERROR CORRECTING CODES; MONTE CARLO METHOD
20080048134 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Flow Solver for Incompressible 2-D Drive Cavity
Kalb, Virginia L.; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): GSC-15107-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3181
This software solves the Navier-Stokes equations for the incompressible driven cavity flow problem. The code uses second-order finite differencing on a staggered grid using the Chorin projection method. The resulting intermediate Poisson equation is efficiently solved using the fast Fourier transform. Time stepping is done using fourth-order Runge-Kutta for stability at high Reynolds numbers. Features include check-pointing, periodic field snapshots, ongoing reporting of kinetic energy and changes between time steps, time histories at selected points, and optional streakline generation.
Author
FLOW VISUALIZATION; INCOMPRESSIBLE FLOW; FINITE DIFFERENCE THEORY; CAVITY FLOW; NAVIER-STOKES EQUATION
20080048135 California Inst. of Tech., Pasadena, CA, United States
Parallel Computing for the Computed-Tomography Imaging Spectrometer
Lee, Seungwon; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45831.; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3208
This software computes the tomographic reconstruction of spatial-spectral data from raw detector images of the Computed-Tomography Imaging Spectrometer (CTIS), which enables transient-level, multi-spectral imaging by capturing spatial and spectral information in a single snapshot.
Author
IMAGING TECHNIQUES; PARALLEL PROCESSING (COMPUTERS); TOMOGRAPHY; GROUND PENETRATING RADAR; COMPUTER PROGRAMS
20080048136 California Inst. of Tech., Pasadena, CA, United States
Calculations for Calibration of a Mass Spectrometer
Lee, Seungwon; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45181; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3199
A computer program performs calculations to calibrate a quadrupole mass spectrometer in an instrumentation system for identifying trace amounts of organic chemicals in air. In the operation of the mass spectrometer, the mass-to-charge ratio (m/z) of ions being counted at a given instant of time is a function of the instantaneous value of a repeating ramp voltage waveform applied to electrodes. The count rate as a function of time can be converted to an m/z spectrum (equivalent to a mass spectrum for singly charged ions), provided that a calibration of m/z is available. The present computer program can perform the calibration in either or both of two ways: (1) Following a data-based approach, it can utilize the count-rate peaks and the times thereof measured when fed with air containing known organic compounds. (2) It can utilize a theoretical proportionality between the instantaneous m/z and the instantaneous value of an oscillating applied voltage. The program can also estimate the error of the calibration performed by the data-based approach. If calibrations are performed in both ways, then the results can be compared to obtain further estimates of errors.
Author
MASS SPECTROMETERS; CALIBRATING
20080048137 California Inst. of Tech., Pasadena, CA, United States
Fault-Tolerant, Multiple-Zone Temperature Control
Granger, James; Franklin, Brian; Michalik, Martin; Yates, Phillip; Peterson, Erik; Borders, James; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English; Original contains color illustrations
Report No.(s): NPO-45230; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3186
A computer program has been written as an essential part of an electronic temperature control system for a spaceborne instrument that contains several zones. The system was developed because the temperature and the rate of change of temperature in each zone are required to be maintained to within limits that amount to degrees of precision thought to be unattainable by use of simple bimetallic thermostats. The software collects temperature readings from six platinum resistance thermometers, calculates temperature errors from the readings, and implements a proportional + integral + derivative (PID) control algorithm that adjusts heater power levels. The software accepts, via a serial port, commands to change its operational parameters. The software attempts to detect and mitigate a host of potential faults. It is robust to many kinds of faults in that it can maintain PID control in the presence of those faults.
Author
COMPUTER PROGRAMS; FAULT TOLERANCE; TEMPERATURE CONTROL; SPACECRAFT ELECTRONIC EQUIPMENT
20080048138 Aerospace Corp., United States; California Inst. of Tech., Pasadena, CA, United States
SPICE Module for the Satellite Orbit Analysis Program (SOAP)
Coggi, John; Carnright, Robert; Hildebrand, Claude; NASA Tech Briefs, September 2008; September 2008; pp. 61-6; In English
Report No.(s): NPO-45057; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3216
A SPICE module for the Satellite Orbit Analysis Program (SOAP) precisely represents complex motion and maneuvers in an interactive, 3D animated environment with support for user-defined quantitative outputs. (SPICE stands for Spacecraft, Planet, Instrument, Camera-matrix, and Events). This module enables the SOAP software to exploit NASA mission ephemeris represented in the JPL Ancillary Information Facility (NAIF) SPICE formats. Ephemeris types supported include position, velocity, and orientation for spacecraft and planetary bodies including the Sun, planets, natural satellites, comets, and asteroids. Entire missions can now be imported into SOAP for 3D visualization, playback, and analysis. The SOAP analysis and display features can now leverage detailed mission files to offer the analyst both a numerically correct and aesthetically pleasing combination of results that can be varied to study many hypothetical scenarios. The software provides a modeling and simulation environment that can encompass a broad variety of problems using orbital prediction. For example, ground coverage analysis, communications analysis, power and thermal analysis, and 3D visualization that provide the user with insight into complex geometric relations are included. The SOAP SPICE module allows distributed science and engineering teams to share common mission models of known pedigree, which greatly reduces duplication of effort and the potential for error. The use of the software spans all phases of the space system lifecycle, from the study of future concepts to operations and anomaly analysis. It allows SOAP software to correctly position and orient all of the principal bodies of the Solar System within a single simulation session along with multiple spacecraft trajectories and the orientation of mission payloads. In addition to the 3D visualization, the user can define numeric variables and x-y plots to quantitatively assess metrics of interest.
Author
NATURAL SATELLITES; SATELLITE ORBITS; SOLAR SYSTEM; COMPUTER ANIMATION; COMPUTER PROGRAMS
20080048139 California Inst. of Tech., Pasadena, CA, United States
Post-Flight Estimation of Motion of Space Structures: Part 1
Brugarolas, Paul; Breckenridge, William; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): NPO-45072; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3188
A computer program estimates the relative positions and orientations of two space structures from data on the angular positions and distances of fiducial objects on one structure as measured by a target tracking electronic camera and laser range finders on another structure. The program is written specifically for determining the relative alignments of two antennas, connected by a long truss, deployed in outer space from a space shuttle. The program is based partly on transformations among the various coordinate systems involved in the measurements and on a nonlinear mathematical model of vibrations of the truss. The program implements a Kalman filter that blends the measurement data with data from the model. Using time series of measurement data from the tracking camera and range finders, the program generates time series of data on the relative position and orientation of the antennas. A similar program described in a prior NASA Tech Briefs article was used onboard for monitoring the structures during flight. The present program is more precise and designed for use on Earth in post-flight processing of the measurement data to enable correction, for antenna motions, of scientific data acquired by use of the antennas.
Author
COMPUTER PROGRAMS; MATHEMATICAL MODELS; SPACECRAFT STRUCTURES; SPACE SHUTTLES
20080048140 California Inst. of Tech., Pasadena, CA, United States
Post-Flight Estimation of Motion of Space Structures: Part 2
Brugarolas, Paul; Breckenridge, William; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): NPO-45074; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/index2.php?option=com_content&task=emailform&id=3
A computer program related to the one described in the immediately preceding article estimates the relative position of two space structures that are hinged to each other. The input to the program consists of time-series data on distances, measured by two range finders at different positions on one structure, to a corner-cube retroreflector on the other structure. Given a Cartesian (x,y,z) coordinate system and the known x coordinate of the retroreflector relative to the y,z plane that contains the range finders, the program estimates the y and z coordinates of the retroreflector. The estimation process involves solving for the y,z coordinates of the intersection between (1) the y,z plane that contains the retroreflector and (2) spheres, centered on the range finders, having radii equal to the measured distances. In general, there are two such solutions and the program chooses the one consistent with the design of the structures. The program implements a Kalman filter. The output of the program is a time series of estimates of the relative position of the structures.
Author
LARGE SPACE STRUCTURES; ESTIMATING; COMPUTER PROGRAMS; POSITION INDICATORS; RETROREFLECTORS
20080048141 California Inst. of Tech., Pasadena, CA, United States
Implementing a Digital Phasemeter in an FPGA
Rao, Shanti R.; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English; Original contains color illustrations
Report No.(s): NPO-45575; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3187
Firmware for implementing a digital phasemeter within a field-programmable gate array (FPGA) has been devised. In the original application of this firmware, the phase that one seeks to measure is the difference between the phases of two nominally-equal-frequency heterodyne signals generated by two interferometers. In that application, zero-crossing detectors convert the heterodyne signals to trains of rectangular pulses, the two pulse trains are fed to a fringe counter (the major part of the phasemeter) controlled by a clock signal having a frequency greater than the heterodyne frequency, and the fringe counter computes a time-averaged estimate of the difference between the phases of the two pulse trains. The firmware also does the following: Causes the FPGA to compute the frequencies of the input signals; Causes the FPGA to implement an Ethernet (or equivalent) transmitter for readout of phase and frequency values; and Provides data for use in diagnosis of communication failures. The readout rate can be set, by programming, to a value between 250 Hz and 1 kHz. Network addresses can be programmed by the user.
Author
FIELD-PROGRAMMABLE GATE ARRAYS; PULSE COMMUNICATION; ELECTRONICS; SOFTWARE ENGINEERING
20080048142 Rowan Univ., Glassboro, NJ, United States; Jacobs Sverdrup Technology, Inc., United States
Intelligent Integrated Health Management for a System of Systems
Smith, Harvey; Schmalzel, John; Figueroa, Fernando; NASA Tech Briefs, September 2008; September 2008; pp. 38-3; In English; Original contains color illustrations
Report No.(s): SSC-00234; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3150
An intelligent integrated health management system (IIHMS) incorporates major improvements over prior such systems. The particular IIHMS is implemented for any system defined as a hierarchical distributed network of intelligent elements (HDNIE), comprising primarily: (1) an architecture (Figure 1), (2) intelligent elements, (3) a conceptual framework and taxonomy (Figure 2), and (4) and ontology that defines standards and protocols. Some definitions of terms are prerequisite to a further brief description of this innovation: A system-of-systems (SoS) is an engineering system that comprises multiple subsystems (e.g., a system of multiple possibly interacting flow subsystems that include pumps, valves, tanks, ducts, sensors, and the like); 'Intelligent' is used here in the sense of artificial intelligence. An intelligent element may be physical or virtual, it is network enabled, and it is able to manage data, information, and knowledge (DIaK) focused on determining its condition in the context of the entire SoS; As used here, 'health' signifies the functionality and/or structural integrity of an engineering system, subsystem, or process (leading to determination of the health of components); 'Process' can signify either a physical process in the usual sense of the word or an element into which functionally related sensors are grouped; 'Element' can signify a component (e.g., an actuator, a valve), a process, a controller, an actuator, a subsystem, or a system; The term Integrated System Health Management (ISHM) is used to describe a capability that focuses on determining the condition (health) of every element in a complex system (detect anomalies, diagnose causes, prognosis of future anomalies), and provide data, information, and knowledge (DIaK) not just data to control systems for safe and effective operation. A major novel aspect of the present development is the concept of intelligent integration. The purpose of intelligent integration, as defined and implemented in the present IIHMS, is to enable automated analysis of physical phenomena in imitation of human reasoning, including the use of qualitative methods. Intelligent integration is said to occur in a system in which all elements are intelligent and can acquire, maintain, and share knowledge and information. In the HDNIE of the present IIHMS, an SoS is represented as being operationally organized in a hierarchical-distributed format. The elements of the SoS are considered to be intelligent in that they determine their own conditions within an integrated scheme that involves consideration of data, information, knowledge bases, and methods that reside in all elements of the system. The conceptual framework of the HDNIE and the methodologies of implementing it enable the flow of information and knowledge among the elements so as to make possible the determination of the condition of each element. The necessary information and knowledge is made available to each affected element at the desired time, satisfying a need to prevent information overload while providing context-sensitive information at the proper level of detail. Provision of high-quality data is a central goal in designing this or any IIHMS. In pursuit of this goal, functionally related sensors are logically assigned to groups denoted processes. An aggregate of processes is considered to form a system. Alternatively or in addition to what has been said thus far, the HDNIE of this IIHMS can be regarded as consisting of a framework containing object models that encapsulate all elements of the system, their individual and relational knowledge bases, generic methods and procedures based on models of the applicable physics, and communication processes (Figure 2). The framework enables implementation of a paradigm inspired by how expert operators monitor the health of systems with the help of (1) DIaK from various sources, (2) software tools that assist in rapid visualization of the condition of the system, (3) analical software tools that assist in reasoning about the condition, (4) sharing of information via network communication hardware and software, and (5) software tools that aid in making decisions to remedy unacceptable conditions or improve performance.
Author
SYSTEMS ENGINEERING; SYSTEMS INTEGRATION; SYSTEMS MANAGEMENT; SYSTEMS HEALTH MONITORING; SMART STRUCTURES; ARTIFICIAL INTELLIGENCE; DECISION SUPPORT SYSTEMS
20080048143 California Inst. of Tech., Pasadena, CA, United States
Near-Field Spectroscopy with Nanoparticles Deposited by AFM
Anderson, Mark S.; NASA Tech Briefs, September 2008; September 2008; pp. 30-3; In English; Original contains color illustrations
Report No.(s): NPO-44033; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3143
An alternative approach to apertureless near-field optical spectroscopy involving an atomic-force microscope (AFM) entails less complexity of equipment than does a prior approach. The alternative approach has been demonstrated to be applicable to apertureless near-field optical spectroscopy of the type using an AFM and surface enhanced Raman scattering (SERS), and is expected to be equally applicable in cases in which infrared or fluorescence spectroscopy is used. Apertureless near-field optical spectroscopy is a means of performing spatially resolved analyses of chemical compositions of surface regions of nanostructured materials. In apertureless near-field spectroscopy, it is common practice to utilize nanostructured probe tips or nanoparticles (usually of gold) having shapes and dimensions chosen to exploit plasmon resonances so as to increase spectroscopic-signal strengths. To implement the particular prior approach to which the present approach is an alternative, it is necessary to integrate a Raman spectrometer with an AFM and to utilize a special SERS-active probe tip. The resulting instrumentation system is complex, and the tasks of designing and constructing the system and using the system to acquire spectro-chemical information from nanometer-scale regions on a surface are correspondingly demanding.
Author
CHEMICAL ANALYSIS; INFRARED SPECTROSCOPY; SURFACE PROPERTIES; RAMAN SPECTRA; PLASMONS; ATOMS; NEAR FIELDS; NANOPARTICLES
20080048144 NASA Ames Research Center, Moffett Field, CA, United States
Light Collimator and Monitor for a Spectroradiometer
Gore, Warren; NASA Tech Briefs, September 2008; September 2008; pp. 3; In English; Original contains color illustrations
Report No.(s): ARC-15714-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3147
A system that comprises optical and electronic subsystems has been developed as an infrastructure for a spectroradiometer that measures time-dependent spectral radiance of the daylight sky, in a narrow field of view (having angular width of the order of 1 ) centered on the zenith, in several spectral bands in the wavelength range from 0.3 to 2.2 m. This system is used in conjunction with two commercially available monolithic spectrometers: a silicon-based one for wavelengths from 0.3 to 1.1 m and a gallium arsenide-based one for wavelengths from 1.05 to 2.2 m (see figure). The role of this system is to collect the light from the affected region of the sky, collimate the light, deliver the collimated light to the monolithic spectrometers, and process the electronic outputs of the spectrometers
Author
COLLIMATORS; GALLIUM ARSENIDES; SPECTRAL BANDS; SPECTRORADIOMETERS; TIME DEPENDENCE; FIELD OF VIEW
20080048145 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Magic-T Junction using Microstrip/Slotline Transitions
U-yen, Kongpop; Wollack, Edward J.; Doiron, Terence; NASA Tech Briefs, September 2008; September 2008; pp. 9-1; In English; Original contains color illustrations
Report No.(s): GSC-15470-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3095
An improved broadband planar magic-T junction that incorporates microstrip/slotline transitions has been developed. In comparison with a prior broadband magic-T junction incorporating microstrip/slotline transitions, this junction offers superior broadband performance. In addition, because this junction is geometrically simpler and its performance is less affected by fabrication tolerances, the benefits of the improved design can be realized at lower fabrication cost. There are potential uses for junctions like this one in commercial microwave communication receivers, radar and polarimeter systems, and industrial microwave instrumentation. A magic-T junction is a four-port waveguide junction consisting of a combination of an H-type and an E-type junction. An E-type junction is so named because it includes a junction arm that extends from a main waveguide in the same direction as that of the electric (E) field in the waveguide. An H-type junction is so named because it includes a junction arm parallel to the magnetic (H) field in a main waveguide. A magic-T junction includes two input ports (here labeled 1 and 2, respectively) and two output ports (here labeled E and H, respectively). In an ideal case, (1) a magic-T junction is lossless, (2) the input signals add (that is, they combine in phase with each other) at port H, and (3) the input signals subtract (that is, they combine in opposite phase) at port E. The prior junction over which the present junction is an improvement affords in-phase-combining characterized by a broadband frequency response, and features a small slotline area to minimize in-band loss. However, with respect to isolation between ports 1 and 2 and return loss at port E, it exhibits narrowband frequency responses. In addition, its performance is sensitive to misalignment of microstrip and slotline components: this sensitivity is attributable to a limited number of quarter-wavelength (lambda/4) transmission-line sections for matching impedances among all four ports, and to strong parasitic couplings at the microstrip/slotline T junction, where four microstrip lines and a slotline are combined. The present improved broadband magic-T junction (see figure) includes a microstrip ring structure and two microstrip- to-slotline transitions. One of the microstrip/slotline transitions is a small T junction between the ring and a slotline; the other microstrip/slotline transition effects coupling between the slotline and port E. The smallness of the T junction and the use of minimum-size slotline terminations help to minimize radiation loss. An impedance-transformation network that includes multiple quarter-wavelength sections is used to increase the operating bandwidth and minimize the parasitic coupling around the microstrip/slotline T junction. As a result, the improved junction has greater bandwidth and lower phase imbalance at the sum and difference ports than did the prior junction.
Author
BROADBAND; COUPLINGS; IMPEDANCE MATCHING; MICROSTRIP TRANSMISSION LINES; MICROWAVE EQUIPMENT; RADIO RECEIVERS; TELECOMMUNICATION; MAGIC TEES
20080048146 California Inst. of Tech., Pasadena, CA, United States
Delaying Trains of Short Light Pulses in WGM Resonators
Matsko, Andrey; Iltchenko, Vladimir; Strekalov, Dmitry; Savchenkov, Anatoliy; Maleki, Lute; NASA Tech Briefs, September 2008; September 2008; pp. 3; In English; Original contains black and white illustrations
Report No.(s): NPO-44956; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3160
Suitably configured whispering-gallery-mode (WGM) optical resonators have been proposed as delay lines for trains of short light pulses. Until now, it has been common practice to implement an optical delay line as a coiled long optical fiber, which is bulky and tends to be noisy. An alternative has been to implement an optical delay line as a coupled-resonator optical waveguide (a chain of coupled optical resonators), which is compact but limits the width of the pulse spectrum to the width of an optical resonance and thereby places a lower limit on the duration of a pulse. In contrast, a delay line according to the proposal could be implemented as a single WGM resonator, and the pulses delayed by the resonator could be so short that their spectral widths could greatly exceed the spectral width of any single resonance. The proposal emerged from theoretical and experimental studies of the propagation of a pulse train in a WGM resonator. An important element of the theoretical study was recognition that the traditional definition of group velocity in effect, the velocity of a single pulse comprising a packet of waves propagating in a medium, the responsivity of which is a monotonous function of frequency does not necessarily apply in the case of a WGM resonator or other medium having a spectrum consisting of discrete resonance peaks at different frequencies. A new definition of group velocity, applicable to a train of pulses propagating in such a medium, was introduced and found to lead to the discovery of previously unknown features of propagation. Notably, it was found that in a micro - sphere optical resonator that supports a suitable combination of WGM modes, the group velocity for a train of light pulses could be positive, zero, or negative. A positive group velocity could be so small that the delay could be much longer than the ring-down time of the resonator; a delay of such great length is impossible for a single pulse interacting with either a linearly responding lossless resonator or a coupled- resonator optical waveguide.
Author
OPTICAL RESONATORS; OPTICAL WAVEGUIDES; DELAY LINES; OPTICAL RESONANCE; SPECTRA
20080048147 California Inst. of Tech., Pasadena, CA, United States
Multichannel Networked Phasemeter Readout and Analysis
Edmonds, Karina; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45505; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3203
Netmeter software reads a data stream from up to 250 networked phasemeters, synchronizes the data, saves the reduced data to disk (after applying a low-pass filter), and provides a Web server interface for remote control. Unlike older phasemeter software that requires a special, real-time operating system, this program can run on any general-purpose computer. It needs about five percent of the CPU (central processing unit) to process 20 channels because it adds built-in data logging and network-based GUIs (graphical user interfaces) that are implemented in Scalable Vector Graphics (SVG). Netmeter runs on Linux and Windows. It displays the instantaneous displacements measured by several phasemeters at a user-selectable rate, up to 1 kHz. The program monitors the measure and reference channel frequencies. For ease of use, levels of status in Netmeter are color coded: green for normal operation, yellow for network errors, and red for optical misalignment problems. Netmeter includes user-selectable filters up to 4 k samples, and user-selectable averaging windows (after filtering). Before filtering, the program saves raw data to disk using a burst-write technique.
Author
READOUT; SOFTWARE ENGINEERING; COMPUTER NETWORKS; MULTICHANNEL COMMUNICATION; COMPUTER GRAPHICS
20080048148 California Inst. of Tech., Pasadena, CA, United States
Simulating the Phoenix Landing Radar System
Chen, Curtis W.; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English; Original contains color illustrations
Report No.(s): NPO-44431; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3184
A computer program called phxlrsim simulates the behavior of the radar system used as an altimeter and velocimeter during the entry, descent, and landing phases of the Phoenix lander spacecraft. The simulation includes modeling of internal functions of the radar system, the spacecraft trajectory, and the terrain. The computational models incorporate representations of nonideal hardware effects in the radar system and effects of radar speckle (coherent scatter of radar signals from terrain).
Author
PHOENIX MARS LANDER; COMPUTER PROGRAMS; COMPUTERIZED SIMULATION; MATHEMATICAL MODELS; SPACECRAFT LANDING
20080048149 NASA Glenn Research Center, Cleveland, OH, United States
Platform for Postprocessing Waveform-Based NDE
Roth, Don; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English; Original contains color illustrations
Report No.(s): LEW-18261-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3205
Taking advantage of the similarities that exist among all waveform-based non-destructive evaluation (NDE) methods, a common software platform has been developed containing multiple- signal and image-processing techniques for waveforms and images. The NASA NDE Signal and Image Processing software has been developed using the latest versions of LabVIEW, and its associated Advanced Signal Processing and Vision Toolkits. The software is useable on a PC with Windows XP and Windows Vista. The software has been designed with a commercial grade interface in which two main windows, Waveform Window and Image Window, are displayed if the user chooses a waveform file to display. Within these two main windows, most actions are chosen through logically conceived run-time menus. The Waveform Window has plots for both the raw time-domain waves and their frequency- domain transformations (fast Fourier transform and power spectral density). The Image Window shows the C-scan image formed from information of the time-domain waveform (such as peak amplitude) or its frequency-domain transformation at each scan location. The user also has the ability to open an image, or series of images, or a simple set of X-Y paired data set in text format. Each of the Waveform and Image Windows contains menus from which to perform many user actions. An option exists to use raw waves obtained directly from scan, or waves after deconvolution if system wave response is provided. Two types of deconvolution, time-based subtraction or inverse-filter, can be performed to arrive at a deconvolved wave set. Additionally, the menu on the Waveform Window allows preprocessing of waveforms prior to image formation, scaling and display of waveforms, formation of different types of images (including non-standard types such as velocity), gating of portions of waves prior to image formation, and several other miscellaneous and specialized operations. The menu available on the Image Window allows many further image processing and analysis operations, some of which are found in commercially-available image-processing software programs (such as Adobe Photoshop), and some that are not (removing outliers, Bscan information, region-of-interest analysis, line profiles, and precision feature measurements).
Author
IMAGE PROCESSING; NONDESTRUCTIVE TESTS; WAVEFORMS; SOFTWARE ENGINEERING; SIGNAL PROCESSING
20080048150 California Inst. of Tech., Pasadena, CA, United States
Progress in Acoustic Transmission of Power through Walls
Sherrit,Stewart; Coty, Benjamin; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea; Chang, Zensheu; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): NPO-44928; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3154
A document presents updated information on implementation of the wireless acoustic-electric feed-through (WAEF) concept, which was reported in Using Piezoelectric Devices To Transmit Power Through Walls (NPO-41157), NASA Tech Briefs, Vol. 32, No. 6 (June 2008), page 70. To recapitulate: In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall is driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall converts the vibrations back to an ultrasonic AC electric signal, which is then detected and otherwise processed in a manner that depends on the modulation (if any) applied to the signal and whether the signal is used to transmit power, data, or both. The present document expands upon the previous information concerning underlying physical principles, advantages, and potential applications of WAEF. It discusses the design and construction of breadboard prototype piezoelectric transducers for WAEF. It goes on to present results of computational simulations of performance and results of laboratory tests of the prototypes. In one notable test, a 100-W light bulb was lit by WAEF to demonstrate the feasibility of powering a realistic load.
Author
ACOUSTIC PROPAGATION; PIEZOELECTRIC TRANSDUCERS; SOUND TRANSMISSION; WALLS; PIEZOELECTRICITY
20080048151 California Inst. of Tech., Pasadena, CA, United States
Simulating the Gradually Deteriorating Performance of an RTG
Wood, Eric G.; Ewell, Richard C.; Patel, Jagdish; Hanks, David R.; Lozano, Juan A.; Snyder, G. Jeffrey; Noon, Larry; NASA Tech Briefs, September 2008; September 2008; pp. 51-5; In English
Report No.(s): NPO-45252; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3200
Degra (now in version 3) is a computer program that simulates the performance of a radioisotope thermoelectric generator (RTG) over its lifetime. Degra is provided with a graphical user interface that is used to edit input parameters that describe the initial state of the RTG and the time-varying loads and environment to which it will be exposed. Performance is computed by modeling the flows of heat from the radioactive source and through the thermocouples, also allowing for losses, to determine the temperature drop across the thermocouples. This temperature drop is used to determine the open-circuit voltage, electrical resistance, and thermal conductance of the thermocouples. Output power can then be computed by relating the open-circuit voltage and the electrical resistance of the thermocouples to a specified time-varying load voltage. Degra accounts for the gradual deterioration of performance attributable primarily to decay of the radioactive source and secondarily to gradual deterioration of the thermoelectric material. To provide guidance to an RTG designer, given a minimum of input, Degra computes the dimensions, masses, and thermal conductances of important internal structures as well as the overall external dimensions and total mass.
Author
RADIOISOTOPE HEAT SOURCES; THERMOELECTRIC GENERATORS; PERFORMANCE TESTS; DEGRADATION; COMPUTER PROGRAMS; COMPUTERIZED SIMULATION
20080048152 Resodyn Corp., United States
Thermal Spray Formation of Polymer Coatings
Coquill, Scott; Galbraith, Stephen L.; Tuss. Darren L.; Ivosevic, Milan; NASA Tech Briefs, September 2008; September 2008; pp. 1; In English
Report No.(s): LEW-18246-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3118
This innovation forms a sprayable polymer film using powdered precursor materials and an in-process heating method. This device directly applies a powdered polymer onto a substrate to form an adherent, mechanically-sound, and thickness-regulated film. The process can be used to lay down both fully dense and porous, e.g., foam, coatings. This system is field-deployable and includes power distribution, heater controls, polymer constituent material bins, flow controls, material transportation functions, and a thermal spray apparatus. The only thing required for operation in the field is a power source. Because this method does not require solvents, it does not release the toxic, volatile organic compounds of previous methods. Also, the sprayed polymer material is not degraded because this method does not use hot combustion gas or hot plasma gas. This keeps the polymer from becoming rough, porous, or poorly bonded.
Author
SPRAYED COATINGS; POLYMERS; HIGH TEMPERATURE PLASMAS; POLYMERIC FILMS
20080048153 California Inst. of Tech., Pasadena, CA, United States
HEMT Amplifiers and Equipment for their On-Wafer Testing
Fung, King man; Gaier, Todd; Samoska, Lorene; Deal, William; Radisic, Vesna; Mei, Xiaobing; Lai, Richard; NASA Tech Briefs, September 2008; September 2008; pp. 12-1; In English; Original contains color illustrations
Report No.(s): NPO-45022; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3082
Power amplifiers comprising InP-based high-electron-mobility transistors (HEMTs) in coplanar-waveguide (CPW) circuits designed for operation at frequencies of hundreds of gigahertz, and a test set for onwafer measurement of their power levels have been developed. These amplifiers utilize an advanced 35-nm HEMT monolithic microwave integrated-circuit (MMIC) technology and have potential utility as local-oscillator drivers and power sources in future submillimeter-wavelength heterodyne receivers and imaging systems. The test set can reduce development time by enabling rapid output power characterization, not only of these and similar amplifiers, but also of other coplanar-waveguide power circuits, without the necessity of packaging the circuits.
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HIGH ELECTRON MOBILITY TRANSISTORS; INTEGRATED CIRCUITS; WAFERS; HETERODYNING; IMAGING TECHNIQUES; WAVEGUIDES
20080048154 Columbus Technologies and Services, Inc., Pasadena, CA, United States
MISR Instrument Data Visualization
Nelson, David; Garay, Michael; Diner, David; Thompson, Charles; Hall, Jeffrey; Rheingans, Brian; Mazzoni, Dominic; NASA Tech Briefs, September 2008; September 2008; pp. 54-5; In English
Report No.(s): NPO-45744; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3204
The MISR Interactive eXplorer (MINX) software functions both as a general-purpose tool to visualize Multiangle Imaging SpectroRadiometer (MISR) instrument data, and as a specialized tool to analyze properties of smoke, dust, and volcanic plumes. It includes high-level options to create map views of MISR orbit locations; scrollable, single-camera RGB (red-greenblue) images of MISR level 1B2 (L1B2) radiance data; and animations of the nine MISR camera images that provide a 3D perspective of the scenes that MISR has acquired. NASA Tech Briefs, September 2008 55 The plume height capability provides an accurate estimate of the injection height of plumes that is needed by air quality and climate modelers. MISR provides global high-quality stereo height information, and this program uses that information to perform detailed height retrievals of aerosol plumes. Users can interactively digitize smoke, dust, or volcanic plumes and automatically retrieve heights and winds, and can also archive MISR albedos and aerosol properties, as well as fire power and brightness temperatures associated with smoke plumes derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data. Some of the specialized options in MINX enable the user to do other tasks. Users can display plots of top-of-atmosphere bidirectional reflectance factors (BRFs) versus camera-angle for selected pixels. Images and animations can be saved to disk in various formats. Also, users can apply a geometric registration correction to warp camera images when the standard processing correction is inadequate. It is possible to difference the images of two MISR orbits that share a path (identical ground track), as well as to construct pseudo-color images by assigning different combinations of MISR channels (angle or spectral band) to the RGB display channels. This software is an interactive application written in IDL and compiled into an IDL Virtual Machine (VM) ".sav" file.
Author
IMAGING SPECTROMETERS; MISR (RADIOMETRY); MODIS (RADIOMETRY); SCIENTIFIC VISUALIZATION
20080048155 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States; California Inst. of Tech., Pasadena, CA, United States
Short- and Long-Term Propagation of Spacecraft Orbits
Smith, John C., Jr.; Sweetser, Theodore; Chung, Min-Kun; Yen, Chen-Wan L.; Roncoli, Ralph B.; Kwok, Johnny H.; Vincent, Mark A.; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45418; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3195
The Planetary Observer Planning Software (POPS) comprises four computer programs for use in designing orbits of spacecraft about planets. These programs are the Planetary Observer High Precision Orbit Propagator (POHOP), the Planetary Observer Long-Term Orbit Predictor (POLOP), the Planetary Observer Post Processor (POPP), and the Planetary Observer Plotting (POPLOT) program. POHOP and POLOP integrate the equations of motion to propagate an initial set of classical orbit elements to a future epoch. POHOP models shortterm (one revolution) orbital motion; POLOP averages out the short-term behavior but requires far less processing time than do older programs that perform long-term orbit propagations. POPP postprocesses the spacecraft ephemeris created by POHOP or POLOP (or optionally can use a less accurate internal ephemeris) to search for trajectory-related geometric events including, for example, rising or setting of a spacecraft as observed from a ground site. For each such event, POPP puts out such user-specified data as the time, elevation, and azimuth. POPLOT is a graphics program that plots data generated by POPP. POPLOT can plot orbit ground tracks on a world map and can produce a variety of summaries and generic ordinate-vs.-abscissa plots of any POPP data.
Author
SPACECRAFT ORBITS; PROPAGATION; CELESTIAL MECHANICS; ORBITAL ELEMENTS; CENTRAL PROCESSING UNITS
20080048156 California Inst. of Tech., Pasadena, CA, United States
Microgravity, Mesh-Crawling Legged Robots
Behar, Alberto; Marzwell, Neville; Matthews, Jaret; Richardson, Krandalyn; Wall, Jonathan; Poole, Michael; Foor, David; Rodgers, Damian; NASA Tech Briefs, September 2008; September 2008; pp. 2; In English; Original contains color illustrations
Report No.(s): NPO-42672; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3137
The design, fabrication, and microgravity flight-testing are part of a continuing development of palm-sized mobile robots that resemble spiders (except that they have six legs apiece, whereas a spider has eight legs). Denoted SpiderBots (see figure), they are prototypes of proposed product line of relatively inexpensive walking robots that could be deployed in large numbers to function cooperatively in construction, repair, exploration, search, and rescue activities in connection with exploration of outer space and remote planets.
Author
FABRICATION; ROBOTS; WALKING; MESH
20080048157 California Inst. of Tech., Pasadena, CA, United States
Improved Silica Aerogel Composite Materials
Paik, Jong-Ah; Sakamoto, Jeffrey; Jones, Steven; NASA Tech Briefs, September 2008; September 2008; pp. 18-1; In English; Original contains color illustrations
Report No.(s): NPO-44287; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3125
A family of aerogel-matrix composite materials having thermal-stability and mechanical- integrity properties better than those of neat aerogels has been developed. Aerogels are known to be excellent thermal- and acoustic-insulation materials because of their molecular-scale porosity, but heretofore, the use of aerogels has been inhibited by two factors: (1) Their brittleness makes processing and handling difficult. (2) They shrink during production and shrink more when heated to high temperatures during use. The shrinkage and the consequent cracking make it difficult to use them to encapsulate objects in thermal-insulation materials. The underlying concept of aerogel-matrix composites is not new; the novelty of the present family of materials lies in formulations and processes that result in superior properties, which include (1) much less shrinkage during a supercritical-drying process employed in producing a typical aerogel, (2) much less shrinkage during exposure to high temperatures, and (3) as a result of the reduction in shrinkage, much less or even no cracking.
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AEROGELS; COMPOSITE MATERIALS; ENCAPSULATING; SILICON DIOXIDE; THERMAL STABILITY; BRITTLENESS; CRACKING (FRACTURING); ELIMINATION; SHRINKAGE
20080048158 California Inst. of Tech., Pasadena, CA, United States
Injecting Artificial Memory Errors Into a Running Computer Program
Bornstein, Benjamin J.; Granat, Robert A.; Wagstaff, Kiri L.; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): NPO-45368; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3185
Single-event upsets (SEUs) or bitflips are computer memory errors caused by radiation. BITFLIPS (Basic Instrumentation Tool for Fault Localized Injection of Probabilistic SEUs) is a computer program that deliberately injects SEUs into another computer program, while the latter is running, for the purpose of evaluating the fault tolerance of that program. BITFLIPS was written as a plug-in extension of the open-source Valgrind debugging and profiling software. BITFLIPS can inject SEUs into any program that can be run on the Linux operating system, without needing to modify the program s source code. Further, if access to the original program source code is available, BITFLIPS offers fine-grained control over exactly when and which areas of memory (as specified via program variables) will be subjected to SEUs. The rate of injection of SEUs is controlled by specifying either a fault probability or a fault rate based on memory size and radiation exposure time, in units of SEUs per byte per second. BITFLIPS can also log each SEU that it injects and, if program source code is available, report the magnitude of effect of the SEU on a floating-point value or other program variable.
Author
MEMORY (COMPUTERS); PROGRAM VERIFICATION (COMPUTERS); UNIX (OPERATING SYSTEM); SYSTEMATIC ERRORS; FAULT TOLERANCE; ARTIFICIAL INTELLIGENCE
20080048159 NASA Johnson Space Center, Houston, TX, United States
Simulating Avionics Upgrades to the Space Shuttles
Deger, Daniel; Hill, Kenneth; Braaten, Karsten E.; NASA Tech Briefs, September 2008; September 2008; pp. 45-4; In English
Report No.(s): MSC-23453-1/15-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3183
Cockpit Avionics Prototyping Environment (CAPE) is a computer program that simulates the functions of proposed upgraded avionics for a space shuttle. In CAPE, pre-existing space-shuttle-simulation programs are merged with a commercial-off-the-shelf (COTS) display-development program, yielding a package of software that enables high-fi46 NASA Tech Briefs, September 2008 delity simulation while making it possible to rapidly change avionic displays and the underlying model algorithms. The pre-existing simulation programs are Shuttle Engineering Simulation, Shuttle Engineering Simulation II, Interactive Control and Docking Simulation, and Shuttle Mission Simulator playback. The COTS program Virtual Application Prototyping System (VAPS) not only enables the development of displays but also makes it possible to move data about, capture and process events, and connect to a simulation. VAPS also enables the user to write code in the C or C++ programming language and compile that code into the end-product simulation software. As many as ten different avionic-upgrade ideas can be incorporated in a single compilation and, thus, tested in a single simulation run. CAPE can be run in conjunction with any or all of four simulations, each representing a different phase of a space-shuttle flight.
Author
AVIONICS; COMPUTERIZED SIMULATION; SPACE SHUTTLE MISSIONS; DISPLAY DEVICES; COCKPITS
20080048160 Innovative Concepts in Engineering, LLC, Anchorage, AK, United States
Automated Assistance for Designing Active Magnetic Bearings
Imlach, Joseph; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English; Original contains color illustrations
Report No.(s): SSC-00176-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3191
MagBear12 is a computer code that assists in the design of radial, heteropolar active magnetic bearings (AMBs). MagBear12 was developed to help in designing the system described in "Advanced Active-Magnetic-Bearing Thrust-Measurement System". Beyond this initial application, MagBear12 is expected to be useful for designing AMBs for a variety of rotating machinery. This program incorporates design rules and governing equations that are also implemented in other, proprietary design software used by AMB manufacturers. In addition, this program incorporates an advanced unpublished fringing-magnetic-field model that increases accuracy beyond that offered by the other AMB-design software.
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COMPUTER PROGRAMS; MAGNETIC BEARINGS; COMPUTER AIDED DESIGN
20080048161 NASA Glenn Research Center, Cleveland, OH, United States
Simulating Operation of a Large Turbofan Engine
Litt, Jonathan S.; Frederick, Dean K.; DeCastro, Jonathan; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): LEW-18315-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3190
The Commercial Modular Aero- Propulsion System Simulation (C-MAPSS) is a computer program for simulating transient operation of a commercial turbofan engine that can generate as much as 90,000 lb (.0.4 MN) of thrust. It includes a power-management system that enables simulation of open- or closed-loop engine operation over a wide range of thrust levels throughout the full range of flight conditions. C-MAPSS provides the user with a set of tools for performing open- and closed-loop transient simulations and comparison of linear and non-linear models throughout its operating envelope, in an easy-to-use graphical environment.
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TURBOFAN ENGINES; COMPUTERIZED SIMULATION; FLIGHT SIMULATION; FLIGHT CONDITIONS
20080048162 NASA Langley Research Center, Hampton, VA, United States
2D/3D Synthetic Vision Navigation Display
Prinzel, Lawrence J., III; Kramer, Lynda J.; Arthur, J. J., III; Bailey, Randall E.; Sweeters, jason L.; NASA Tech Briefs, September 2008; September 2008; pp. 53-5; In English; Original contains color illustrations
Report No.(s): LAR-17354; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3201
Flight-deck display software was designed and developed at NASA Langley Research Center to provide two-dimensional (2D) and three-dimensional (3D) terrain, obstacle, and flight-path perspectives on a single navigation display. The objective was to optimize the presentation of synthetic vision (SV) system technology that permits pilots to view multiple perspectives of flight-deck display symbology and 3D terrain information. Research was conducted to evaluate the efficacy of the concept. The concept has numerous unique implementation features that would permit enhanced operational concepts and efficiencies in both current and future aircraft.
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FLIGHT CONTROL; NAVIGATION AIDS; ENHANCED VISION; DISPLAY DEVICES
20080048163 Science Systems and Applications, Inc., Bay Saint Louis, MS, United States
Hyperspectral Fluorescence and Reflectance Imaging Instrument
Ryan, Robert E.; O'Neal, S. Duane; Lanoue, Mark; Russell, Jeffrey; NASA Tech Briefs, September 2008; September 2008; pp. 3; In English
Report No.(s): SSC-00254,; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3146
The system is a single hyperspectral imaging instrument that has the unique capability to acquire both fluorescence and reflectance high-spatial-resolution data that is inherently spatially and spectrally registered. Potential uses of this instrument include plant stress monitoring, counterfeit document detection, biomedical imaging, forensic imaging, and general materials identification. Until now, reflectance and fluorescence spectral imaging have been performed by separate instruments. Neither a reflectance spectral image nor a fluorescence spectral image alone yields as much information about a target surface as does a combination of the two modalities. Before this system was developed, to benefit from this combination, analysts needed to perform time-consuming post-processing efforts to co-register the reflective and fluorescence information. With this instrument, the inherent spatial and spectral registration of the reflectance and fluorescence images minimizes the need for this post-processing step. The main challenge for this technology is to detect the fluorescence signal in the presence of a much stronger reflectance signal. To meet this challenge, the instrument modulates artificial light sources from ultraviolet through the visible to the near-infrared part of the spectrum; in this way, both the reflective and fluorescence signals can be measured through differencing processes to optimize fluorescence and reflectance spectra as needed. The main functional components of the instrument are a hyperspectral imager, an illumination system, and an image-plane scanner. The hyperspectral imager is a one-dimensional (line) imaging spectrometer that includes a spectrally dispersive element and a two-dimensional focal plane detector array. The spectral range of the current imaging spectrometer is between 400 to 1,000 nm, and the wavelength resolution is approximately 3 nm. The illumination system consists of narrowband blue, ultraviolet, and other discrete wavelength light-emitting-diode (LED) sources and white-light LED sources designed to produce consistently spatially stable light. White LEDs provide illumination for the measurement of reflectance spectra, while narrowband blue and UV LEDs are used to excite fluorescence. Each spectral type of LED can be turned on or off depending on the specific remote-sensing process being performed. Uniformity of illumination is achieved by using an array of LEDs and/or an integrating sphere or other diffusing surface. The image plane scanner uses a fore optic with a field of view large enough to provide an entire scan line on the image plane. It builds up a two-dimensional image in pushbroom fashion as the target is scanned across the image plane either by moving the object or moving the fore optic. For fluorescence detection, spectral filtering of a narrowband light illumination source is sometimes necessary to minimize the interference of the source spectrum wings with the fluorescence signal. Spectral filtering is achieved with optical interference filters and absorption glasses. This dual spectral imaging capability will enable the optimization of reflective, fluorescence, and fused datasets as well as a cost-effective design for multispectral imaging solutions. This system has been used in plant stress detection studies and in currency analysis.
Author
FINITE DIFFERENCE THEORY; LIGHT EMITTING DIODES; OPTICAL FILTERS; REMOTE SENSING; SPECTRAL REFLECTANCE; FIELD OF VIEW; SPATIAL RESOLUTION
20080048164 NASA Langley Research Center, Hampton, VA, United States
Predicting Boundary-Layer Transition on Space-Shuttle Re-Entry
Berry, Scott; Horvath, Tom; Merski, Ron; Liechty, Derek; Greene, Frank; Bibb, Karen; Buck, Greg; Hamilton, Harris; Weilmuenster, Jim; Campbell, Chuck; Bouslog, Stan; Kirk, Ben; Bourland, Garry; Cassady, Amy; Anderson, Brian; Reda, Dan; Reuther, James; Kinder, Gerry; Chao, Dennis; Hyatt, Jay; Barnwell, Maria; Wang, K. C.; Schneider, Steve; NASA Tech Briefs, September 2008; September 2008; pp. 52-5; In English; Original contains color illustrations
Report No.(s): LAR-17337-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3198
The BLT Prediction Tool ("BLT" signifies "Boundary Layer Transition") is provided as part of the Damage Assessment Team analysis package, which is utilized for analyzing local aerothermodynamics environments of damaged or repaired space-shuttle thermal protection tiles. Such analyses are helpful in deciding whether to repair launch-induced damage before re-entering the terrestrial atmosphere.
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AEROTHERMODYNAMICS; BOUNDARY LAYER TRANSITION; DAMAGE ASSESSMENT; COMPUTER PROGRAMS; SPACE SHUTTLE ORBITERS
20080048165 California Inst. of Tech., Pasadena, CA, United States
Automatic Rock Detection and Mapping from HiRISE Imagery
Huertas, Andres; Adams, Douglas S.; Cheng, Yang; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45752; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3207
This system includes a C-code software program and a set of MATLAB software tools for statistical analysis and rock distribution mapping. The major functions include rock detection and rock detection validation. The rock detection code has been evolved into a production tool that can be used by engineers and geologists with minor training.
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COMPUTER PROGRAMS; DETECTION; IMAGERY; ROCKS; IMAGE PROCESSING; IMAGING TECHNIQUES
20080048166 United Space Alliance, Houston, TX, United States
Computational Model of Heat Transfer on the ISS
Torian, John G.; Rischar, Michael L.; NASA Tech Briefs, September 2008; September 2008; pp. 49-5; In English
Report No.(s): MSC-23622-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3193
SCRAM Lite (SCRAM signifies Station Compact Radiator Analysis Model) is a computer program for analyzing convective and radiative heat-transfer and heat-rejection performance of coolant loops and radiators, respectively, in the active thermal-control systems of the International Space Station (ISS). SCRAM Lite is a derivative of prior versions of SCRAM but is more robust. SCRAM Lite computes thermal operating characteristics of active heat-transport and heat-rejection subsystems for the major ISS configurations from Flight 5A through completion of assembly. The program performs integrated analysis of both internal and external coolant loops of the various ISS modules and of an external active thermal control system, which includes radiators and the coolant loops that transfer heat to the radiators. The SCRAM Lite run time is of the order of one minute per day of mission time. The overall objective of the SCRAM Lite simulation is to process input profiles of equipment-rack, crew-metabolic, and other heat loads to determine flow rates, coolant supply temperatures, and available radiator heat-rejection capabilities. Analyses are performed for timelines of activities, orbital parameters, and attitudes for mission times ranging from a few hours to several months.
Author
HEAT TRANSFER; INTERNATIONAL SPACE STATION; HEAT RADIATORS; ACTIVE CONTROL; TEMPERATURE CONTROL; COMPUTER PROGRAMS
20080048167 California Inst. of Tech., Pasadena, CA, United States
Optimization of Angular-Momentum Biases of Reaction Wheels
Lee, Clifford; Lee, Allan; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-42011; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3194
RBOT [RWA Bias Optimization Tool (wherein RWA signifies Reaction Wheel Assembly )] is a computer program designed for computing angular momentum biases for reaction wheels used for providing spacecraft pointing in various directions as required for scientific observations. RBOT is currently deployed to support the Cassini mission to prevent operation of reaction wheels at unsafely high speeds while minimizing time in undesirable low-speed range, where elasto-hydrodynamic lubrication films in bearings become ineffective, leading to premature bearing failure. The problem is formulated as a constrained optimization problem in which maximum wheel speed limit is a hard constraint and a cost functional that increases as speed decreases below a low-speed threshold. The optimization problem is solved using a parametric search routine known as the Nelder-Mead simplex algorithm. To increase computational efficiency for extended operation involving large quantity of data, the algorithm is designed to (1) use large time increments during intervals when spacecraft attitudes or rates of rotation are nearly stationary, (2) use sinusoidal-approximation sampling to model repeated long periods of Earth-point rolling maneuvers to reduce computational loads, and (3) utilize an efficient equation to obtain wheel-rate profiles as functions of initial wheel biases based on conservation of angular momentum (in an inertial frame) using pre-computed terms.
Author
ANGULAR MOMENTUM; BIAS; COMPUTER PROGRAMS; REACTION WHEELS; OPTIMIZATION
20080048168 California Inst. of Tech., Pasadena, CA, United States
Making More-Complex Molecules Using Superthermal Atom/Molecule Collisions
Shortt, Brian; Chutjian, Ara; Orient, Otto; NASA Tech Briefs, September 2008; September 2008; pp. 1; In English; Original contains color illustrations
Report No.(s): NPO-41300; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3120
A method of making more-complex molecules from simpler ones has emerged as a by-product of an experimental study in outer-space atom/surface collision physics. The subject of the study was the formation of CO2 molecules as a result of impingement of O atoms at controlled kinetic energies upon cold surfaces onto which CO molecules had been adsorbed. In this study, the O/CO system served as a laboratory model, not only for the formation of CO2 but also for the formation of other compounds through impingement of rapidly moving atoms upon molecules adsorbed on such cold interstellar surfaces as those of dust grains or comets. By contributing to the formation of increasingly complex molecules, including organic ones, this study and related other studies may eventually contribute to understanding of the origins of life.
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COLD SURFACES; MOLECULAR INTERACTIONS; CRYOGENICS; ATOMIC COLLISIONS
20080048169 H and R Technical Associates, Inc., United States
Computational Simulation of a Water-Cooled Heat Pump
Bozarth, Duane; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): MSC-23375-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3192
A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL).
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APPLICATIONS PROGRAMS (COMPUTERS); HEAT PUMPS; COMPUTERIZED SIMULATION
20080048170 Houston Univ., TX, United States
Group-III Nitride Field Emitters
Bensaoula, Abdelhak; Berishev, Igor; NASA Tech Briefs, September 2008; September 2008; pp. 11-1; In English
Report No.(s): MFS-32514-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3094
Field-emission devices (cold cathodes) having low electron affinities can be fabricated through lattice-mismatched epitaxial growth of nitrides of elements from group III of the periodic table. Field emission of electrons from solid surfaces is typically utilized in vacuum microelectronic devices, including some display devices. The present field-emission devices and the method of fabricating them were developed to satisfy needs to reduce the cost of fabricating field emitters, make them compatible with established techniques for deposition of and on silicon, and enable monolithic integration of field emitters with silicon-based driving circuitry. In fabricating a device of this type, one deposits a nitride of one or more group-III elements on a substrate of (111) silicon or other suitable material. One example of a suitable deposition process is chemical vapor deposition in a reactor that contains plasma generated by use of electron cyclotron resonance. Under properly chosen growth conditions, the large mismatch between the crystal lattices of the substrate and the nitride causes strains to accumulate in the growing nitride film, such that the associated stresses cause the film to crack. The cracks lie in planes parallel to the direction of growth, so that the growing nitride film becomes divided into microscopic growing single-crystal columns. The outer ends of the fully-grown columns can serve as field-emission tips. By virtue of their chemical compositions and crystalline structures, the columns have low work functions and high electrical conductivities, both of which are desirable for field emission of electrons. From examination of transmission electron micrographs of a prototype device, the average column width was determined to be about 100 nm and the sharpness of the tips was determined to be characterized by a dimension somewhat less than 100 nm. The areal density of the columns was found to about 5 x 10(exp 9)/sq cm . about 4 to 5 orders of magnitude greater than the areal density of tips in prior field-emission devices. The electric field necessary to turn on the emission current and the current per tip in this device are both lower than in prior field-emission devices, such that it becomes possible to achieve longer operational lifetime. Moreover, notwithstanding the lower current per tip, because of the greater areal density of tips, it becomes possible to achieve greater current density averaged over the cathode area. The thickness of the grown nitride film (equivalently, the length of the columns) could lie between about 0.5 microns and a few microns; in any event, a thickness of about 1 micron is sufficient and costs less than do greater thicknesses. It may be possible to grow nitride emitter columns on glass or other substrate materials that cost less than silicon does. What is important in the choice of substrate material is the difference between the substrate and nitride crystalline structures. Inasmuch as the deposition process is nondestructive, an ability to grow emitter columns on a variety of materials would be advantageous in that it would facilitate the integration of field-emitter structures onto previously processed integrated circuits.
Author
FIELD EMISSION; MICROELECTRONICS; COLD CATHODES; CRYSTAL STRUCTURE; ELECTRON CYCLOTRON RESONANCE; DISPLAY DEVICES
20080048171 California Inst. of Tech., Pasadena, CA, United States
Adaptive MGS Phase Retrieval
Basinger, Scott A.; Bikkannavar, Siddarayappa; Cohen, David; Green, Joseph J.; Lou, John; Ohara, Catherine; Redding, David; Shi, Fang; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-43857; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3197
Adaptive MGS Phase Retrieval software uses the Modified Gerchberg-Saxton (MGS) algorithm, an image-based sensing method that can turn any focal plane science instrument into a wavefront sensor, avoiding the need to use external metrology equipment. Knowledge of the wavefront enables intelligent control of active optical systems.
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ALGORITHMS; IMAGE ANALYSIS; METROLOGY; OPTICAL MEASUREMENT
20080048172 California Inst. of Tech., Pasadena, CA, United States
Automated Camera Array Fine Calibration
Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45505; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3202
Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.
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AERIAL PHOTOGRAPHY; CALIBRATING; CAMERAS; IMAGE PROCESSING; COMPUTER PROGRAMS
20080048173 California Inst. of Tech., Pasadena, CA, United States
Rock Segmentation through Edge Regrouping
Burl, Michael; NASA Tech Briefs, September 2008; September 2008; pp. 56-5; In English; Original contains color illustrations
Report No.(s): NPO-44417; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3210
Rockster is an algorithm that automatically identifies the locations and boundaries of rocks imaged by the rover hazard cameras (hazcams), navigation cameras (navcams), or panoramic cameras (pancams). The software uses edge detection and edge regrouping to identify closed contours that separate the rocks from the background.
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ALGORITHMS; EDGE DETECTION; POSITION (LOCATION); ROCKS; IMAGING TECHNIQUES; IMAGE PROCESSING
20080048174 California Inst. of Tech., Pasadena, CA, United States
Nano-Engineered Catalysts for Direct Methanol Fuel Cells
Myung, Nosang; Narayanan, Sekharipuram; Wiberg, Dean; NASA Tech Briefs, September 2008; September 2008; pp. 6-; In English; Original contains color and black and white illustrations
Report No.(s): NPO-30840; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3080
Nano-engineered catalysts, and a method of fabricating them, have been developed in a continuing effort to improve the performances of direct methanol fuel cells as candidate power sources to supplant primary and secondary batteries in a variety of portable electronic products. In order to realize the potential for high energy densities (as much as 1.5 W h/g) of direct methanol fuel cells, it will be necessary to optimize the chemical compositions and geometric configurations of catalyst layers and electrode structures. High performance can be achieved when catalyst particles and electrode structures have the necessary small feature sizes (typically of the order of nanometers), large surface areas, optimal metal compositions, high porosity, and hydrophobicity. The present method involves electrodeposition of one or more catalytic metal(s) or a catalytic-metal/polytetrafluoroethylene nanocomposite on an alumina nanotemplate. The alumina nanotemplate is then dissolved, leaving the desired metal or metal/polytetrafluoroethylene-composite catalyst layer. Unlike some prior methods of making fine metal catalysts, this method does not involve processing at elevated temperature; all processing can be done at room temperature. In addition, this method involves fewer steps and is more amenable to scaling up for mass production. Alumina nanotemplates are porous alumina membranes that have been fabricated, variously, by anodizing either pure aluminum or aluminum that has been deposited on silicon by electronbeam evaporation. The diameters of the pores (7 to 300 nm), areal densities of pores (as much as 7 x 10(exp 10)sq cm), and lengths of pores (up to about 100 nm) can be tailored by selection of fabrication conditions. In a given case, the catalytic metal, catalytic metal alloy, or catalytic metal/ polytetrafluoroethylene composite is electrodeposited in the pores of the alumina nanotemplate. The dimensions of the pores, together with the electrodeposition conditions, determine the sizes and surface areas of the catalytic particles. Hence, the small features and large surface areas of the porosity translate to the desired small particle size and large surface area of the catalyst (see figure). When polytetrafluoroethylene is included, it is for the purpose of imparting hydrophobicity in order to prevent water from impeding the desired diffusion of gases through the catalyst layer. To incorporate polytetrafluoroethylene into a catalytic-metal/polytetrafluoroethylene nanocomposite, one suspends polytetrafluoroethylene nanoparticles in the electrodeposition solution. The polytetrafluoroethylene content can be varied to obtain the desired degree of hydrophobicity and permeability by gas.
Author
CATALYSTS; ELECTROCATALYSTS; NANOCOMPOSITES; METHYL ALCOHOL; NANOPARTICLES; FUEL CELLS; ELECTRODEPOSITION; GASEOUS DIFFUSION
20080048175 California Inst. of Tech., Pasadena, CA, United States
Nanotip Carpets as Antireflection Surfaces
Bae, Youngsam; Mobasser, Sohrab; Manohara, Harish; Lee, Choonsup; NASA Tech Briefs, September 2008; September 2008; pp. 5-; In English; Original contains color and black and white illustrations
Report No.(s): NPO-42592; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3070
Carpet-like random arrays of metal-coated silicon nanotips have been shown to be effective as antireflection surfaces. Now undergoing development for incorporation into Sun sensors that would provide guidance for robotic exploratory vehicles on Mars, nanotip carpets of this type could also have many uses on Earth as antireflection surfaces in instruments that handle or detect ultraviolet, visible, or infrared light. In the original Sun-sensor application, what is required is an array of 50-micron-diameter apertures on what is otherwise an opaque, minimally reflective surface, as needed to implement a miniature multiple-pinhole camera. The process for fabrication of an antireflection nanotip carpet for this application (see Figure 1) includes, and goes somewhat beyond, the process described in A New Process for Fabricating Random Silicon Nanotips (NPO-40123), NASA Tech Briefs, Vol. 28, No. 1 (November 2004), page 62. In the first step, which is not part of the previously reported process, photolithography is performed to deposit etch masks to define the 50-micron apertures on a silicon substrate. In the second step, which is part of the previously reported process, the non-masked silicon area between the apertures is subjected to reactive ion etching (RIE) under a special combination of conditions that results in the growth of fluorine-based compounds in randomly distributed formations, known in the art as "polymer RIE grass," that have dimensions of the order of microns. The polymer RIE grass formations serve as microscopic etch masks during the next step, in which deep reactive ion etching (DRIE) is performed. What remains after DRIE is the carpet of nano - tips, which are high-aspect-ratio peaks, the tips of which have radii of the order of nanometers. Next, the nanotip array is evaporatively coated with Cr/Au to enhance the absorption of light (more specifically, infrared light in the Sun-sensor application). The photoresist etch masks protecting the apertures are then removed by dipping the substrate into acetone. Finally, for the Sun-sensor application, the back surface of the substrate is coated with a 57-nm-thick layer of Cr for attenuation of sunlight.
Author
ANTIREFLECTION COATINGS; SOLAR SENSORS; ROBOTICS; PHOTOLITHOGRAPHY; MINIATURIZATION; ELECTROMAGNETIC ABSORPTION; SILICON
20080048176 California Inst. of Tech., Pasadena, CA, United States
UV-Resistant Non-Spore-Forming Bacteria From Spacecraft-Assembly Facilities
Venkateswaran, Kasthuri; NASA Tech Briefs, September 2008; September 2008; pp. 2; In English
Report No.(s): NPO-45739; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3142
Four species of non-spore-forming bacteria collected from clean-room surfaces in spacecraft-assembly facilities could survive doses of ultraviolet (UV) radiation that would suffice to kill most known cultivable bacterial species. In a previous study, high UV resistance was found in spores of the SAFR-032 strain of Bacillus pumilus, as reported in "Ultraviolet- Resistant Bacterial Spores," NASA Tech Briefs, Vol. 31, No. 9 (September 2007), page 94. These studies are parts of a continuing effort to understand the survival of hardy species of bacteria under harsh conditions, and develop means of sterilizing spacecraft to prevent biocontamination of Mars that could in turn interfere with future life detection missions. The four species investigated were Arthrobacter sp. KSC_Ak2i, Microbacterium schleiferi LMA_AkK1, Brevundimonas diminuta KSC_Ak3a, and Sphingomonas trueperi JSC_Ak7-3. In the study, cells of these species were mixed into Atacama Desert soil (to elucidate the shadowing effect of soil particles) and the resulting mixtures were tested both in solution and in a desiccated state under simulated Martian atmospheric and UV conditions. The UV-survival indices of Arthrobacter sp. and Microbacterium schleiferi were found to be comparable to those of Bacillus pumilus spores.
Author
BACTERIA; ULTRAVIOLET RADIATION; SPORES; METEOROLOGY
20080048177 Wiesen Engine, Inc., United States
A New, Highly Improved Two-Cycle Engine
Wiesen, Bernard; NASA Tech Briefs, September 2008; September 2008; pp. 23-2; In English
Report No.(s): LEW-18043-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3135
The figure presents a cross-sectional view of a supercharged, variable-compression, two-cycle, internal-combustion engine that offers significant advantages over prior such engines. The improvements are embodied in a combination of design changes that contribute synergistically to improvements in performance and economy. Although the combination of design changes and the principles underlying them are complex, one of the main effects of the changes on the overall engine design is reduced (relative to prior two-cycle designs) mechanical complexity, which translates directly to reduced manufacturing cost and increased reliability. Other benefits include increases in the efficiency of both scavenging and supercharging. The improvements retain the simplicity and other advantages of two-cycle engines while affording increases in volumetric efficiency and performance across a wide range of operating conditions that, heretofore have been accessible to four-cycle engines but not to conventionally scavenged two-cycle ones, thereby increasing the range of usefulness of the two-cycle engine into all areas now dominated by the four-cycle engine. The design changes and benefits are too numerous to describe here in detail, but it is possible to summarize the major improvements: Reciprocating Shuttle Inlet Valve The entire reciprocating shuttle inlet valve and its operating gear is constructed as a single member. The shuttle valve is actuated in a lost-motion arrangement in which, at the ends of its stroke, projections on the shuttle valve come to rest against abutments at the ends of grooves in a piston skirt. This shuttle-valve design obviates the customary complex valve mechanism, actuated from an engine crankshaft or camshaft, yet it is effective with every type of two-cycle engine, from small high-speed single cylinder model engines, to large low-speed multiple cylinder engines.
Author
INTERNAL COMBUSTION ENGINES; ENGINE DESIGN; VOLUMETRIC EFFICIENCY; DESIGN ANALYSIS
20080048178 NASA Langley Research Center, Hampton, VA, United States
Displaying CFD Solution Parameters on Arbitrary Cut Planes
Pao, S. Paul; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): LAR-17527-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/content/view/3180/123
USMC6 is a Fortran 90 computer program for post-processing in support of visualization of flows simulated by computational fluid dynamics (CFD). The name "USMC6" is partly an abbreviation of "TetrUSS - USM3D Solution Cutter," reflecting its origin as a post-processor for use with USM3D - a CFD program that is a component of the Tetrahedral Unstructured Software System and that solves the Navier-Stokes equations on tetrahedral unstructured grids. "Cutter" here refers to a capability to acquire and process solution data on (1) arbitrary planes that cut through grid volumes, or (2) user-selected spheroidal, conical, cylindrical, and/or prismatic domains cut from within grids. Cutting saves time by enabling concentration of post-processing and visualization efforts on smaller solution domains of interest. The user can select from among more than 40 flow functions. The cut planes can be trimmed to circular or rectangular shape. The user specifies cuts and functions in a free-format input file using simple and easy-to-remember keywords. The USMC6 command line is simple enough that the slicing process can readily be embedded in a shell script for assembly-line post-processing. The output of USMC6 is a data file ready for plotting.
Author
COMPUTATIONAL FLUID DYNAMICS; UNSTRUCTURED GRIDS (MATHEMATICS); COMPUTER PROGRAMS; FORTRAN; APPLICATIONS PROGRAMS (COMPUTERS)
20080048179 California Inst. of Tech., Pasadena, CA, United States
DSN Array Simulator
Tikidjian, Raffi; Mackey, Ryan; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English; Original contains color illustrations
Report No.(s): NPO-44506; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3211
The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.
Author
DEEP SPACE NETWORK; COMPUTERIZED SIMULATION; COMPUTER PROGRAMS; INTERPLANETARY COMMUNICATION
20080048180 California Inst. of Tech., Pasadena, CA, United States
On-Wafer Measurement of a Silicon-Based CMOS VCO at 324 GHz
Samoska, Lorene; Man Fung, King; Gaier, Todd; Huang, Daquan; Larocca, Tim; Chang, M. F.; Campbell, Richard; Andrews, Michael; NASA Tech Briefs, September 2008; September 2008; pp. 1; In English; Original contains color illustrations
Report No.(s): NPO-45494; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3092
The world s first silicon-based complementary metal oxide/semiconductor (CMOS) integrated-circuit voltage-controlled oscillator (VCO) operating in a frequency range around 324 GHz has been built and tested. Concomitantly, equipment for measuring the performance of this oscillator has been built and tested. These accomplishments are intermediate steps in a continuing effort to develop low-power-consumption, low-phase-noise, electronically tunable signal generators as local oscillators for heterodyne receivers in submillimeter-wavelength (frequency > 300 GHz) scientific instruments and imaging systems. Submillimeter-wavelength imaging systems are of special interest for military and law-enforcement use because they could, potentially, be used to detect weapons hidden behind clothing and other opaque dielectric materials. In comparison with prior submillimeter- wavelength signal generators, CMOS VCOs offer significant potential advantages, including great reductions in power consumption, mass, size, and complexity. In addition, there is potential for on-chip integration of CMOS VCOs with other CMOS integrated circuitry, including phase-lock loops, analog- to-digital converters, and advanced microprocessors.
Author
CMOS; INTEGRATED CIRCUITS; VOLTAGE CONTROLLED OSCILLATORS; SIGNAL GENERATORS; ANALOG TO DIGITAL CONVERTERS; ENERGY CONSUMPTION; IMAGING TECHNIQUES
20080048181 NASA Glenn Research Center, Cleveland, OH, United States
Lightweight Carbon-Carbon High-Temperature Space Radiator
Miller, W.O.; Shih, Wei; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): LEW-18210-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3156
A document summarizes the development of a carbon-carbon composite radiator for dissipating waste heat from a spacecraft nuclear reactor. The radiator is to be bonded to metal heat pipes and to operate in conjunction with them at a temperature approximately between 500 and 1,000 K. A goal of this development is to reduce the average areal mass density of a radiator to about 2 kg/m(exp 2) from the current value of approximately 10 kg/m(exp 2) characteristic of spacecraft radiators made largely of metals. Accomplishments thus far include: (1) bonding of metal tubes to carbon-carbon material by a carbonization process that includes heating to a temperature of 620 C; (2) verification of the thermal and mechanical integrity of the bonds through pressure-cycling, axial-shear, and bending tests; and (3) construction and testing of two prototype heat-pipe/carbon-carbon-radiator units having different radiator areas, numbers of heat pipes, and areal mass densities. On the basis of the results achieved thus far, it is estimated that optimization of design could yield an areal mass density of 2.2 kg/m (exp 2) close to the goal of 2 kg/m(exp 2).
Author
CARBON-CARBON COMPOSITES; SPACECRAFT RADIATORS; RESEARCH AND DEVELOPMENT; DESIGN OPTIMIZATION; PROTOTYPES; WEIGHT REDUCTION
20080048182 NASA Langley Research Center, Hampton, VA, United States; Analytical Mechanics Associates, Inc., United States
Stochastic Analysis of Orbital Lifetimes of Spacecraft
Sasamoto, Washito; Goodliff, Kandyce; Cornelius, David; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): LAR-17498-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3155
A document discusses (1) a Monte-Carlo-based methodology for probabilistic prediction and analysis of orbital lifetimes of spacecraft and (2) Orbital Lifetime Monte Carlo (OLMC)--a Fortran computer program, consisting of a previously developed long-term orbit-propagator integrated with a Monte Carlo engine. OLMC enables modeling of variances of key physical parameters that affect orbital lifetimes through the use of probability distributions. These parameters include altitude, speed, and flight-path angle at insertion into orbit; solar flux; and launch delays. The products of OLMC are predicted lifetimes (durations above specified minimum altitudes) for the number of user-specified cases. Histograms generated from such predictions can be used to determine the probabilities that spacecraft will satisfy lifetime requirements. The document discusses uncertainties that affect modeling of orbital lifetimes. Issues of repeatability, smoothness of distributions, and code run time are considered for the purpose of establishing values of code-specific parameters and number of Monte Carlo runs. Results from test cases are interpreted as demonstrating that solar-flux predictions are primary sources of variations in predicted lifetimes. Therefore, it is concluded, multiple sets of predictions should be utilized to fully characterize the lifetime range of a spacecraft.
Author
ORBITAL LIFETIME; SPACECRAFT; PERFORMANCE PREDICTION; STOCHASTIC PROCESSES; MONTE CARLO METHOD; FORTRAN; APPLICATIONS PROGRAMS (COMPUTERS)
20080048183 California Inst. of Tech., Pasadena, CA, United States
Capillography of Mats of Nanofibers
Noca, Flavio; Sansom, Elijah; Zhou, Jijie; Gharib, Mory; NASA Tech Briefs, September 2008; September 2008; pp. ; In English; Original contains color and black and white illustrations
Report No.(s): NPO-40980; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3081
Capillography (from the Latin capillus, 'hair', and the Greek graphein, to write ) is a recently conceived technique for forming mats of nanofibers into useful patterns. The concept was inspired by experiments on carpetlike mats of multiwalled carbon nanotubes. Capillography may have the potential to be a less-expensive, less-time-consuming alternative to electron-beam lithography as a means of nanoscale patterning for the fabrication of small devices and instruments. In capillography, one exploits the lateral capillary forces exerted on small objects that pierce the surface of a liquid. If the small objects are identical, then the forces are always attractive. Two examples of the effects of such forces are the agglomeration of small particles floating on the surface of a pond and the drawing together of hairs of a wet paintbrush upon removal of the brush from water. Because nanoscale objects brought into contact remain stuck together indefinitely due to Van der Waals forces, patterns formed by capillography remain even upon removal of the liquid. For the experiments on the mats of carbon nanotubes, a surfactant solution capable of wetting carbon nanotubes (which are ultra-hydrophobic) was prepared. The mats were wetted with the solution, then dried. Once the mats were dry, it was found that the nanotubes had become ordered into various patterns, including nestlike indentations, trenches, and various combinations thereof. It may be possible to exploit such ordering effects through controlled wetting and drying of designated portions of mats of carbon nanotubes (and, perhaps, mats of nanofibers of other materials) to obtain patterns similar to those heretofore formed by use of electron-beam lithography. For making patterns that include nestlike indentations, it has been conjectured that it could be possible to control the nesting processes by use of electrostatic fields. Further research is needed to understand the physics of the patterning processes in order to develop capabilities to control patterns formed in capillography.
Author
NANOFABRICATION; FIBERS; CARBON NANOTUBES
20080048184 California Inst. of Tech., Pasadena, CA, United States
Thermally Actuated Hydraulic Pumps
Jones, Jack; Ross, Ronald; Chao, Yi; NASA Tech Briefs, September 2008; September 2008; pp. 22-2; In English; Original contains color illustrations
Report No.(s): NPO-40844; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3139
Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research vessels. Heretofore, electrically actuated hydraulic pumps have been used for this purpose. By eliminating the demand for electrical energy for pumping, the use of the thermally actuated hydraulic pumps could prolong the intervals between battery charges, thus making it possible to greatly increase the durations of undersea exploratory missions.
Author
HYDRAULIC EQUIPMENT; TEMPERATURE EFFECTS; THERMAL EXPANSION; HYDRAULIC CONTROL; HYDRAULIC FLUIDS; PUMPS; COMPRESSORS; HEAT TRANSFER
20080048185 California Inst. of Tech., Pasadena, CA, United States
Service-Oriented Architecture for NVO and TeraGrid Computing
Jacob, Joseph; Miller, Craig; Williams, Roy; Steenberg, Conrad; Graham, Matthew; NASA Tech Briefs, September 2008; September 2008; pp. 6; In English; Original contains color illustrations
Report No.(s): NPO-45067; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3219
The National Virtual Observatory (NVO) Extensible Secure Scalable Service Infrastructure (NESSSI) is a Web service architecture and software framework that enables Web-based astronomical data publishing and processing on grid computers such as the National Science Foundation's TeraGrid. Characteristics of this architecture include the following: (1) Services are created, managed, and upgraded by their developers, who are trusted users of computing platforms on which the services are deployed. (2) Service jobs can be initiated by means of Java or Python client programs run on a command line or with Web portals. (3) Access is granted within a graduated security scheme in which the size of a job that can be initiated depends on the level of authentication of the user.
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CLIENT SERVER SYSTEMS; SERVICE ORIENTED ARCHITECTURE; WEB SERVICES; GRID COMPUTING (COMPUTER NETWORKS)
20080048186 NASA Ames Research Center, Moffett Field, CA, United States
JPEG 2000 Encoding with Perceptual Distortion Control
Watson, Andrew B.; Liu, Zhen; Karam, Lina J.; NASA Tech Briefs, September 2008; September 2008; pp. 37-3; In English; Original contains color illustrations
Report No.(s): ARC-15522-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3149
An alternative approach has been devised for encoding image data in compliance with JPEG 2000, the most recent still-image data-compression standard of the Joint Photographic Experts Group. Heretofore, JPEG 2000 encoding has been implemented by several related schemes classified as rate-based distortion-minimization encoding. In each of these schemes, the end user specifies a desired bit rate and the encoding algorithm strives to attain that rate while minimizing a mean squared error (MSE). While rate-based distortion minimization is appropriate for transmitting data over a limited-bandwidth channel, it is not the best approach for applications in which the perceptual quality of reconstructed images is a major consideration. A better approach for such applications is the present alternative one, denoted perceptual distortion control, in which the encoding algorithm strives to compress data to the lowest bit rate that yields at least a specified level of perceptual image quality. Some additional background information on JPEG 2000 is prerequisite to a meaningful summary of JPEG encoding with perceptual distortion control. The JPEG 2000 encoding process includes two subprocesses known as tier-1 and tier-2 coding. In order to minimize the MSE for the desired bit rate, a rate-distortion- optimization subprocess is introduced between the tier-1 and tier-2 subprocesses. In tier-1 coding, each coding block is independently bit-plane coded from the most-significant-bit (MSB) plane to the least-significant-bit (LSB) plane, using three coding passes (except for the MSB plane, which is coded using only one "clean up" coding pass). For M bit planes, this subprocess involves a total number of (3M - 2) coding passes. An embedded bit stream is then generated for each coding block. Information on the reduction in distortion and the increase in the bit rate associated with each coding pass is collected. This information is then used in a rate-control procedure to determine the contribution of each coding block to the output compressed bit stream.
Author
CODING; DATA COMPRESSION; OPTIMIZATION; MEAN SQUARE VALUES; IMAGE RESOLUTION; DISTORTION
20080048187 California Inst. of Tech., Pasadena, CA, United States
Toward Better Modeling of Supercritical Turbulent Mixing
Selle, Laurent; Okongo'o, Nora; Bellan, Josette; Harstad, Kenneth; NASA Tech Briefs, September 2008; September 2008; pp. 3; In English
Report No.(s): NPO-44402; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3148
study was done as part of an effort to develop computational models representing turbulent mixing under thermodynamic supercritical (here, high pressure) conditions. The question was whether the large-eddy simulation (LES) approach, developed previously for atmospheric-pressure compressible-perfect-gas and incompressible flows, can be extended to real-gas non-ideal (including supercritical) fluid mixtures. [In LES, the governing equations are approximated such that the flow field is spatially filtered and subgrid-scale (SGS) phenomena are represented by models.] The study included analyses of results from direct numerical simulation (DNS) of several such mixing layers based on the Navier-Stokes, total-energy, and conservation- of-chemical-species governing equations. Comparison of LES and DNS results revealed the need to augment the atmospheric- pressure LES equations with additional SGS momentum and energy terms. These new terms are the direct result of high-density-gradient-magnitude regions found in the DNS and observed experimentally under fully turbulent flow conditions. A model has been derived for the new term in the momentum equation and was found to perform well at small filter size but to deteriorate with increasing filter size. Several alternative models were derived for the new SGS term in the energy equation that would need further investigations to determine if they are too computationally intensive in LES.
Author
TURBULENT MIXING; REACTION KINETICS; DIRECT NUMERICAL SIMULATION; FLOW DISTRIBUTION; HIGH PRESSURE; GAS FLOW
20080048188 Innovative Concepts in Engineering, LLC, Anchorage, AK, United States
Advanced Active-Magnetic-Bearing Thrust-Measurement System
Imlach, Joseph; Kasarda, Mary; Blumber, Eric; NASA Tech Briefs, September 2008; September 2008; pp. 21-2; In English
Report No.(s): SSC-00177-1/8-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3138
An advanced thrust-measurement system utilizes active magnetic bearings to both (1) levitate a floating frame in all six degrees of freedom and (2) measure the levitation forces between the floating frame and a grounded frame. This system was developed for original use in measuring the thrust exerted by a rocket engine mounted on the floating frame, but can just as well be used in other force-measurement applications. This system offers several advantages over prior thrust-measurement systems based on mechanical support by flexures and/or load cells: The system includes multiple active magnetic bearings for each degree of freedom, so that by selective use of one, some, or all of these bearings, it is possible to test a given article over a wide force range in the same fixture, eliminating the need to transfer the article to different test fixtures to obtain the benefit of full-scale accuracy of different force-measurement devices for different force ranges. Like other active magnetic bearings, the active magnetic bearings of this system include closed-loop control subsystems, through which the stiffness and damping characteristics of the magnetic bearings can be modified electronically. The design of the system minimizes or eliminates cross-axis force-measurement errors. The active magnetic bearings are configured to provide support against movement along all three orthogonal Cartesian axes, and such that the support along a given axis does not produce force along any other axis. Moreover, by eliminating the need for such mechanical connections as flexures used in prior thrust-measurement systems, magnetic levitation of the floating frame eliminates what would otherwise be major sources of cross-axis forces and the associated measurement errors. Overall, relative to prior mechanical-support thrust-measurement systems, this system offers greater versatility for adaptation to a variety of test conditions and requirements. The basic idea of most prior active-magnetic-bearing force-measurement systems is to calculate levitation forces on the basis of simple proportionalities between changes in those forces and changes in feedback-controlled currents applied to levitating electromagnetic coils. In the prior systems, the effects of gap lengths on fringing magnetic fields and the concomitant effects on magnetic forces were neglected. In the present system, the control subsystems of the active magnetic bearings are coupled with a computer-based automatic calibration system running special-purpose software wherein gap-length-dependent fringing factors are applied to current and magnetic-flux-based force equations and combined with a multipoint calibration method to obtain greater accuracy.
Author
MAGNETIC BEARINGS; THRUST MEASUREMENT; MAGNETIC FLUX; MECHANICAL MEASUREMENT; FEEDBACK CONTROL
20080048189 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Flow Solver for Incompressible Rectangular Domains
Kalb, Virginia L.; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): GSC-15111-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3182
This is an extension of the Flow Solver for Incompressible 2-D Drive Cavity software described in the preceding article. It solves the Navier-Stokes equations for incompressible flow using finite differencing on a uniform, staggered grid. There is a runtime choice of either central differencing or modified upwinding for the convective term. The domain must be rectangular, but may have a rectangular walled region within it. Currently, the position of the interior region and exterior boundary conditions are changed by modifying parameters in the code and recompiling. These features make it possible to solve a variety of classical fluid flow problems such as an L-shaped cavity, channel flow, or wake flow past a square cylinder. The code uses fourth-order Runge-Kutta time-stepping and overall second-order spatial accuracy. This software permits the walled region to be positioned such that flow past a square cylinder, an L-shaped cavity, and the flow over a back-facing step can all be solved by reconfiguration. Also, this extension has an automatic detection of periodicity, as well as use of specialized data structure for ease of configuring domain decomposition and computing convergence in overlap regions.
Author
CHANNEL FLOW; CAVITY FLOW; INCOMPRESSIBLE FLOW; FLUID FLOW; NAVIER-STOKES EQUATION; COMPUTATIONAL FLUID DYNAMICS; COMPUTATIONAL GRIDS
20080048190 California Inst. of Tech., Pasadena, CA, United States
Visual Target Tracking on the Mars Exploration Rovers
Kim, Won; Biesiadecki, Jeffrey; Ali, Khaled; NASA Tech Briefs, September 2008; September 2008; pp. 60-6; In English; Original contains color illustrations
Report No.(s): NPO-45019; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3213
Visual target tracking (VTT) software has been incorporated into Release 9.2 of the Mars Exploration Rover (MER) flight software, now running aboard the rovers Spirit and Opportunity. In the VTT operation (see figure), the rover is driven in short steps between stops and, at each stop, still images are acquired by actively aimed navigation cameras (navcams) on a mast on the rover (see artistic rendition). The VTT software processes the digitized navcam images so as to track a target reliably and to make it possible to approach the target accurately to within a few centimeters over a 10-m traverse.
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APPLICATIONS PROGRAMS (COMPUTERS); MARS ROVING VEHICLES; ROVING VEHICLES; PHOTOGRAPHIC TRACKING; TRACKING (POSITION); AUTOMATIC CONTROL
20080048191 NASA Glenn Research Center, Cleveland, OH, United States
Nematic Cells for Digital Light Deflection
Pishnyak, Oleg; Golovin, Andrii; Laventovich, Oleg; Kreminska, Liubov; Winker, Bruce; Pouch, John; Miranda, Felix; NASA Tech Briefs, September 2008; September 2008; pp. 17-1; In English
Report No.(s): LEW-18215-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3158
Smectic A (SmA) materials can be used in non-mechanical, digital beam deflectors (DBDs) as fillers for passive birefringent prisms based on decoupled pairs of electrically controlled, liquid crystalline polarization rotators, like twisted nematic (TN) cells and passive deflectors. DBDs are used in free-space laser communications, optical fiber communications, optical switches, scanners, and in-situ wavefront correction.
Author
BIREFRINGENCE; DEFLECTION; LIQUID CRYSTALS; LIGHT (VISIBLE RADIATION)
20080048192 California Inst. of Tech., Pasadena, CA, United States
Parametric-Studies and Data-Plotting Modules for the SOAP
NASA Tech Briefs, September 2008; September 2008; pp. 59-6; In English; Original contains color illustrations
Report No.(s): NPO-45059; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3214
"Parametric Studies" and "Data Table Plot View" are the names of software modules in the Satellite Orbit Analysis Program (SOAP). Parametric Studies enables parameterization of as many as three satellite or ground-station attributes across a range of values and computes the average, minimum, and maximum of a specified metric, the revisit time, or 21 other functions at each point in the parameter space. This computation produces a one-, two-, or three-dimensional table of data representing statistical results across the parameter space. Inasmuch as the output of a parametric study in three dimensions can be a very large data set, visualization is a paramount means of discovering trends in the data (see figure). Data Table Plot View enables visualization of the data table created by Parametric Studies or by another data source: this module quickly generates a display of the data in the form of a rotatable three-dimensional-appearing plot, making it unnecessary to load the SOAP output data into a separate plotting program. The rotatable three-dimensionalappearing plot makes it easy to determine which points in the parameter space are most desirable. Both modules provide intuitive user interfaces for ease of use.
Author
COMPUTER PROGRAMS; PARAMETERIZATION; SCIENTIFIC VISUALIZATION; TABLES (DATA); LOADS (FORCES); MODULES
20080048193 Columbia Univ., United States; California Inst. of Tech., Pasadena, CA, United States
Ultra-Stable Beacon Source for Laboratory Testing of Optical Tracking
Aso, Yoichi; Marka, Szabolcs; Kovalik, Joseph; NASA Tech Briefs, September 2008; September 2008; pp. 3; In English; Original contains color and black and white illustrations
Report No.(s): NPO-45127; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3159
The ultra-stable beacon source (USBS) provides a laser-beam output with a very low angular jitter and can be used as an absolute angular reference to simulate a beacon in the laboratory. The laser is mounted on the top of a very short (approximately equal to 1 m) inverted pendulum (IP) with its optical axis parallel to the carbon fiber pendulum leg. The 85-cm, carbon fiber rods making up the leg are very lightweight and rigid, and are supported by a flex-joint at the bottom (see figure). The gimbal-mounted laser is a weight-adjustable load of about 1.5 kg with its center of rotation co-located with the center of percussion of the inverted pendulum. This reduces the coupling of transverse motion at the base of the pendulum to angular motion of the laser at the top. The inverted pendulum is mounted on a gimbal with its center of rotation coinciding with the pivot position of the inverted pendulum flexure joint. This reduces coupling of ground tilt at the inverted pendulum base to motion of the laser mounted at the top. The mass of the top gimbal is adjusted to give the pendulum a very low resonant frequency (approximately equal to 10 mHz) that filters transverse seismic disturbances from the ground where the base is attached. The motion of the IP is monitored by an optical-lever sensor. The laser light is reflected by the mirror on the IP, and then is detected by a quadrant photo-detector (QPD). The position of the beam spot on the QPD corresponds to the tilt of the IP. Damping of this motion is provided by two coil and magnet pairs. The bottom gimbal mount consists of two plates. The IP is mounted on the second plate. The first plate is supported by two posts through needles and can be rotated about the axis connecting the tips of the needles. The second plate hangs from the first plate and can be rotated about the axis perpendicular to the first plate. As a result, the second plate acts as a two-axis rotation stage. Its center of rotation is located at the effective bending point of the flex-joint. The second plate is pressed against two screw actuators by the weight of the IP. The screw actuators are orthogonal to each other and are used to adjust the inclination of the second plate. The actuators are driven by stepper motors. The whole IP system is housed in a box made of Lexan plastic plates to provide isolation from air currents and temperature variations. The signals from the sensors are processed and recorded with a PC using the xPC Target realtime environment of Math- Works. The control algorithms are written using the Simulink package from The MathWorks.
Author
OPTICAL TRACKING; BEACONS; LASER APPLICATIONS
20080048194 California Inst. of Tech., Pasadena, CA, United States
Transmissive Diffractive Optical Element Solar Concentrators
Baron, Richard; Moynihan, Philip; Price, Douglas; NASA Tech Briefs, September 2008; September 2008; pp. 3; In English; Original contains black and white illustrations
Report No.(s): NPO-43801; Copyright; Avail.: CASI: A01, Hardcopy
Solar-thermal-radiation concentrators in the form of transmissive diffractive optical elements (DOEs) have been proposed as alternatives to mirror-type solar concentrators now in use. In comparison with functionally equivalent mirror-type solar concentrators, the transmissive, diffractive solar concentrators would weigh and cost less, and would be subject to relaxed mechanical tolerances. A DOE concentrator would be made from a thin, flat disk or membrane of a transmissive material having a suitable index of refraction. By virtue of its thinness, the DOE concentrator would have an areal mass density significantly less than that of a functionally equivalent conventional mirror. The DOE concentrator would have a relatively wide aperture--characterized by a focal-length/aperture-diameter ratio ('f number') on the order of 1. A kinoform (a surface-relief phase hologram) of high diffractive order would be microfabricated onto one face of the disk. The kinoform (see figure) would be designed to both diffract and refract incident solar radiation onto a desired focal region, without concern for forming an image of the Sun. The high diffractive order of this kinoform (in contradistinction to the low diffractive orders of some other kinoforms) would be necessary to obtain the desired f number of 1, which, in turn, would be necessary for obtaining a desired concentration ratio of 2,500 or greater. The design process of optimizing the concentration ratio of a proposed DOE solar concentrator includes computing convolutions of the optical bandwidth of the Sun with the optical transmission of the diffractive medium. Because, as in the cases of other non-imaging, light-concentrating optics, image quality is not a design requirement, the process also includes trading image quality against concentration ratio. A baseline design for one example calls for an aperture diameter of 1 m. This baseline design would be scalable to a diameter as large as 10 m, or to a smaller diameter for a laboratory test article. Initial calculations have indicated that the characteristics of the test article would be readily scalable to a full-size unit.
Author
SOLAR COLLECTORS; SOLAR RADIATION; THERMAL RADIATION; DIFFRACTIVE OPTICS; DESIGN ANALYSIS; DESIGN OPTIMIZATION; PROTOTYPES
20080048195 NASA Ames Research Center, Moffett Field, CA, United States
Delay Banking for Managing Air Traffic
Green, Steve; NASA Tech Briefs, September 2008; September 2008; pp. 39-4; In English
Report No.(s): ARC-15392-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3151
Delay banking has been invented to enhance air-traffic management in a way that would increase the degree of fairness in assigning arrival, departure, and en-route delays and trajectory deviations to aircraft impacted by congestion in the national airspace system. In delay banking, an aircraft operator (airline, military, general aviation, etc.) would be assigned a numerical credit when any of their flights are delayed because of an air-traffic flow restriction. The operator could subsequently bid against other operators competing for access to congested airspace to utilize part or all of its accumulated credit. Operators utilize credits to obtain higher priority for the same flight, or other flights operating at the same time, or later, in the same airspace, or elsewhere. Operators could also trade delay credits, according to market rules that would be determined by stakeholders in the national airspace system. Delay banking would be administered by an independent third party who would use delay banking automation to continually monitor flights, allocate delay credits, maintain accounts of delay credits for participating airlines, mediate bidding and the consumption of credits of winning bidders, analyze potential transfers of credits within and between operators, implement accepted transfers, and ensure fair treatment of all participating operators. A flow restriction can manifest itself in the form of a delay in assigned takeoff time, a reduction in assigned airspeed, a change in the position for the aircraft in a queue of all aircraft in a common stream of traffic (e.g., similar route), a change in the planned altitude profile for an aircraft, or change in the planned route for the aircraft. Flow restrictions are typically imposed to mitigate traffic congestion at an airport or in a region of airspace, particularly congestion due to inclement weather, or the unavailability of a runway or region of airspace. A delay credit would be allocated to an operator of a flight that has accepted, or upon which was imposed, a flow restriction. The amount of the credit would increase with the amount of delay caused by the flow restriction, the exact amount depending on which of several candidate formulas is eventually chosen. For example, according to one formula, there would be no credit for a delay smaller than some threshold value (e.g., 30 seconds) and the amount of the credit for a longer delay would be set at the amount of the delay minus the threshold value. Optionally, the value of a delay credit could be made to decay with time according to a suitable formula (e.g., an exponential decay). Also, optionally, a transaction charge could be assessed against the value of a delay credit that an operator used on a flight different from the one for which the delay originated or that was traded with a different operator. The delay credits accumulated by a given airline could be utilized in various ways. For example, an operator could enter a bid for priority handling in a new flow restriction that impacts one or more of the operator s flights; if the bid were unsuccessful, all or a portion of the credit would be returned to the bidder. If the bid pertained to a single aircraft that was in a queue, delay credits could be consumed in moving the aircraft to an earlier position within the queue. In the case of a flow restriction involving a choice of alternate routes, planned altitude profile, aircraft spacing, or other non-queue flow restrictions, delay credits could be used to bid for an alternative assignment.
Author
AIR TRAFFIC CONTROL; TIME LAG
20080048196 California Inst. of Tech., Pasadena, CA, United States
System for Continuous Delivery of MODIS Imagery to Internet Mapping Applications
Plesea, Lucian; NASA Tech Briefs, September 2008; September 2008; pp. 5; In English
Report No.(s): NPO-45778; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3206
This software represents a complete, unsupervised processing chain that generates a continuously updating global image of the Earth from the most recent available MODIS Level 1B scenes. The software constantly updates a global image of the Earth at 250 m per pixel.
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IMAGERY; INTERNETS; MODIS (RADIOMETRY); COMPUTER AIDED MAPPING
20080048197 California Inst. of Tech., Pasadena, CA, United States
Facilitating Analysis of Multiple Partial Data Streams
Maimone, Mark W.; Liebersbach, Robert R.; NASA Tech Briefs, September 2008; September 2008; pp. 6; In English; Original contains color illustrations
Report No.(s): NPO-45367; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3218
Robotic Operations Automation: Mechanisms, Imaging, Navigation report Generation (ROAMING) is a set of computer programs that facilitates and accelerates both tactical and strategic analysis of time-sampled data especially the disparate and often incomplete streams of Mars Explorer Rover (MER) telemetry data described in the immediately preceding article. As used here, tactical refers to the activities over a relatively short time (one Martian day in the original MER application) and strategic refers to a longer time (the entire multi-year MER missions in the original application). Prior to installation, ROAMING must be configured with the types of data of interest, and parsers must be modified to understand the format of the input data (many example parsers are provided, including for general CSV files). Thereafter, new data from multiple disparate sources are automatically resampled into a single common annotated spreadsheet stored in a readable space-separated format, and these data can be processed or plotted at any time scale. Such processing or plotting makes it possible to study not only the details of a particular activity spanning only a few seconds, but also longer-term trends. ROAMING makes it possible to generate mission-wide plots of multiple engineering quantities [e.g., vehicle tilt as in Figure 1(a), motor current, numbers of images] that, heretofore could be found only in thousands of separate files. ROAMING also supports automatic annotation of both images and graphs. In the MER application, labels given to terrain features by rover scientists and engineers are automatically plotted in all received images based on their associated camera models (see Figure 2), times measured in seconds are mapped to Mars local time, and command names or arbitrary time-labeled events can be used to label engineering plots, as in Figure 1(b).
Author
DATA FLOW ANALYSIS; MARS SURFACE; ROBOTICS; TELEMETRY; COMPUTER PROGRAMS
20080048198 California Inst. of Tech., Pasadena, CA, United States
Mars Reconnaissance Orbiter Wrapper Script
Gladden, Roy; Fisher, Forest; Khanampornpan, Teerapat; NASA Tech Briefs, September 2008; September 2008; pp. 6; In English; Original contains color illustrations
Report No.(s): NPO-45242; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3220
The MRO OLVM wrapper script software allows Mars Reconnaissance Orbiter (MRO) sequence and spacecraft engineers to rapidly simulate a spacecraft command product through a tool that simulates the onboard sequence management software (OLVM). This script parses sequence files to determine the appropriate time boundaries for the sequence, and constructs the script file to be executed by OLVM to span the entirety of the designated sequence. It then constructs script files to be executed by OLVM, constructs the appropriate file directories, populates these directories with needed input files, initiates OLVM to simulate the actual command product that will be sent to the spacecraft, and captures the results of the simulation run to an external file for later review. Additionally, the tool allows a user to manually construct the script, if desired, and then execute the script with a simple command line.
Author
MARS RECONNAISSANCE ORBITER; COMPUTER SYSTEMS PROGRAMS; COMPUTERIZED SIMULATION; SOFTWARE ENGINEERING; AIRBORNE/SPACEBORNE COMPUTERS
20080048199 California Inst. of Tech., Pasadena, CA, United States
Reducing Spaceborne-Doppler-Radar Rainfall-Velocity Error
Tanelli, Simone; Im, Eastwood; Durden, Stephen L.; NASA Tech Briefs, September 2008; September 2008; pp. 4; In English
Report No.(s): NPO-40590; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3153
A combined frequency-time (CFT) spectral moment estimation technique has been devised for calculating rainfall velocity from measurement data acquired by a nadir-looking spaceborne Doppler weather radar system. Prior spectral moment estimation techniques used for this purpose are based partly on the assumption that the radar resolution volume is uniformly filled with rainfall. The assumption is unrealistic in general but introduces negligible error in application to airborne radar systems. However, for spaceborne systems, the combination of this assumption and inhomogeneities in rainfall [denoted non-uniform beam filling (NUBF)] can result in velocity measurement errors of several meters per second. The present CFT spectral moment estimation technique includes coherent processing of a series of Doppler spectra generated in a standard manner from data over measurement volumes that are partially overlapping in the along-track direction. Performance simulation of this technique using high-resolution data from an airborne rain-mapping radar shows that a spaceborne Ku-band Doppler radar operating at signal-to-noise ratios greater than 10 dB can achieve root-mean-square accuracy between 0.5 and 0.6 m/s in vertical-velocity estimates.
Author
DOPPLER RADAR; METEOROLOGICAL RADAR; RAIN; VELOCITY MEASUREMENT; VELOCITY ERRORS
20080048200 ASRC Aerospace Corp., United States
Monte Carlo Simulation to Estimate Likelihood of Direct Lightning Strikes
Mata, Carlos; Medelius, Pedro; NASA Tech Briefs, September 2008; September 2008; pp. 50-5; In English
Report No.(s): KSC-12882; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3196
A software tool has been designed to quantify the lightning exposure at launch sites of the stack at the pads under different configurations. In order to predict lightning strikes to generic structures, this model uses leaders whose origins (in the x-y plane) are obtained from a 2D random, normal distribution.
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LIGHTNING; MONTE CARLO METHOD; SIMULATION; MAXIMUM LIKELIHOOD ESTIMATES
20080048201 California Inst. of Tech., Pasadena, CA, United States
High-Voltage, Asymmetric-Waveform Generator
Beegle, Luther W.; Duong, Tuan A.; Duong, Vu A.; Kanik, Isik; NASA Tech Briefs, September 2008; September 2008; pp. ; In English; Original contains color illustrations
Report No.(s): NPO-45665; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3093
The shapes of waveforms generated by commercially available analytical separation devices, such as some types of mass spectrometers and differential mobility spectrometers are, in general, inadequate and result in resolution degradation in output spectra. A waveform generator was designed that would be able to circumvent these shortcomings. It is capable of generating an asymmetric waveform, having a peak amplitude as large as 2 kV and frequency of several megahertz, which can be applied to a capacitive load. In the original intended application, the capacitive load would consist of the drift plates in a differential-mobility spectrometer. The main advantage to be gained by developing the proposed generator is that the shape of the waveform is made nearly optimum for various analytical devices requiring asymmetric-waveform such as differential-mobility spectrometers. In addition, this waveform generator could easily be adjusted to modify the waveform in accordance with changed operational requirements for differential-mobility spectrometers. The capacitive nature of the load is an important consideration in the design of the proposed waveform generator. For example, the design provision for shaping the output waveform is based partly on the principle that (1) the potential (V) on a capacitor is given by V=q/C, where C is the capacitance and q is the charge stored in the capacitor; and, hence (2) the rate of increase or decrease of the potential is similarly proportional to the charging or discharging current. The proposed waveform generator would comprise four functional blocks: a sine-wave generator, a buffer, a voltage shifter, and a high-voltage switch (see Figure 1). The sine-wave generator would include a pair of operational amplifiers in a feedback configuration, the parameters of which would be chosen to obtain a sinusoidal timing signal of the desired frequency. The buffer would introduce a slight delay (approximately equal to 20 ns) but would otherwise leave the fundamental timing signal unchanged. The buffered timing signal would be fed as input to the level shifter. The output of the level shifter would serve as a timing and control signal for the high-voltage switch, causing the switch to alternately be (1) opened, allowing the capacitive load to be charged from a high-voltage DC power supply; then (2) closed to discharge the capacitive load to ground. Hence, the output waveform would closely approximate a series of exponential charging and discharging curves (see Figure 2).
Author
WAVEFORMS; HIGH VOLTAGES; CAPACITANCE; ELECTRONIC EQUIPMENT; TEST EQUIPMENT
20080048202 California Inst. of Tech., Pasadena, CA, United States
Purifying Nucleic Acids from Samples of Extremely Low Biomass
La Duc, Myron; Osman, Shariff; Venkateswaran, Kasthuri; NASA Tech Briefs, September 2008; September 2008; pp. 2; In English
Report No.(s): NPO-45740; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3140
A new method is able to circumvent the bias to which one commercial DNA extraction method falls prey with regard to the lysing of certain types of microbial cells, resulting in a truncated spectrum of microbial diversity. By prefacing the protocol with glass-bead-beating agitation (mechanically lysing a much more encompassing array of cell types and spores), the resulting microbial diversity detection is greatly enhanced. In preliminary studies, a commercially available automated DNA extraction method is effective at delivering total DNA yield, but only the non-hardy members of the bacterial bisque were represented in clone libraries, suggesting that this method was ineffective at lysing the hardier cell types. To circumvent such a bias in cells, yet another extraction method was devised. In this technique, samples are first subjected to a stringent bead-beating step, and then are processed via standard protocols. Prior to being loaded into extraction vials, samples are placed in micro-centrifuge bead tubes containing 50 micro-L of commercially produced lysis solution. After inverting several times, tubes are agitated at maximum speed for two minutes. Following agitation, tubes are centrifuged at 10,000 x g for one minute. At this time, the aqueous volumes are removed from the bead tubes and are loaded into extraction vials to be further processed via extraction regime. The new method couples two independent methodologies in such as way as to yield the highest concentration of PCR-amplifiable DNA with consistent and reproducible results and with the most accurate and encompassing report of species richness.
Author
DEOXYRIBONUCLEIC ACID; EXTRACTION; GENETIC ENGINEERING; PURIFICATION
20080048203 Acellent Technologies, Inc., Sunnyvale, CA, United States
Flexible Structural-Health-Monitoring Sheets
Qing, Xinlin; Kuo, Fuo; NASA Tech Briefs, September 2008; September 2008; pp. 2; In English
Report No.(s): MFS-32510-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3136
A generic design for a type of flexible structural-health-monitoring sheet with multiple sensor/actuator types and a method of manufacturing such sheets has been developed. A sheet of this type contains an array of sensing and/or actuation elements, associated wires, and any other associated circuit elements incorporated into various flexible layers on a thin, flexible substrate. The sheet can be affixed to a structure so that the array of sensing and/or actuation elements can be used to analyze the structure in accordance with structural-health-monitoring techniques. Alternatively, the sheet can be designed to be incorporated into the body of the structure, especially if the structure is made of a composite material. Customarily, structural-health monitoring is accomplished by use of sensors and actuators arrayed at various locations on a structure. In contrast, a sheet of the present type can contain an entire sensor/actuator array, making it unnecessary to install each sensor and actuator individually on or in a structure. Sensors of different types such as piezoelectric and fiber-optic can be embedded in the sheet to form a hybrid sensor network. Similarly, the traces for electric communication can be deposited on one or two layers as required, and an entirely separate layer can be employed to shield the sensor elements and traces.
Author
SYSTEMS HEALTH MONITORING; SHEETS; STRUCTURAL ENGINEERING
20080048204 NASA Langley Research Center, Hampton, VA, United States
Spline-Based Smoothing of Airfoil Curvatures
Li, W.; Krist, S.; NASA Tech Briefs, September 2008; September 2008; pp. 40-4; In English; Original contains color illustrations
Report No.(s): LAR-17227-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3152
Constrained fitting for airfoil curvature smoothing (CFACS) is a splinebased method of interpolating airfoil surface coordinates (and, concomitantly, airfoil thicknesses) between specified discrete design points so as to obtain smoothing of surface-curvature profiles in addition to basic smoothing of surfaces. CFACS was developed in recognition of the fact that the performance of a transonic airfoil is directly related to both the curvature profile and the smoothness of the airfoil surface. Older methods of interpolation of airfoil surfaces involve various compromises between smoothing of surfaces and exact fitting of surfaces to specified discrete design points. While some of the older methods take curvature profiles into account, they nevertheless sometimes yield unfavorable results, including curvature oscillations near end points and substantial deviations from desired leading-edge shapes. In CFACS as in most of the older methods, one seeks a compromise between smoothing and exact fitting. Unlike in the older methods, the airfoil surface is modified as little as possible from its original specified form and, instead, is smoothed in such a way that the curvature profile becomes a smooth fit of the curvature profile of the original airfoil specification. CFACS involves a combination of rigorous mathematical modeling and knowledge-based heuristics. Rigorous mathematical formulation provides assurance of removal of undesirable curvature oscillations with minimum modification of the airfoil geometry. Knowledge-based heuristics bridge the gap between theory and designers best practices. In CFACS, one of the measures of the deviation of an airfoil surface from smoothness is the sum of squares of the jumps in the third derivatives of a cubicspline interpolation of the airfoil data. This measure is incorporated into a formulation for minimizing an overall deviation- from-smoothness measure of the airfoil data within a specified fitting error tolerance. CFACS has been extensively tested on a number of supercritical airfoil data sets generated by inverse design and optimization computer programs. All of the smoothing results show that CFACS is able to generate unbiased smooth fits of curvature profiles, trading small modifications of geometry for increasing curvature smoothness by eliminating curvature oscillations and bumps (see figure).
Author
AIRFOILS; CURVATURE; SMOOTHING; SPLINES
20080048205 California Inst. of Tech., Pasadena, CA, United States; Skull Base Inst., United States
Adjustable-Viewing-Angle Endoscopic Tool for Skull Base and Brain Surgery
Bae, Youngsam; Liao, Anna; Manohara, Harish; Shahinian, Hrayr; NASA Tech Briefs, September 2008; September 2008; pp. 27-2; In English; Original contains color illustrations
Report No.(s): NPO-45579; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3141
The term Multi-Angle and Rear Viewing Endoscopic tooL (MARVEL) denotes an auxiliary endoscope, now undergoing development, that a surgeon would use in conjunction with a conventional endoscope to obtain additional perspective. The role of the MARVEL in endoscopic brain surgery would be similar to the role of a mouth mirror in dentistry. Such a tool is potentially useful for in-situ planetary geology applications for the close-up imaging of unexposed rock surfaces in cracks or those not in the direct line of sight. A conventional endoscope provides mostly a frontal view that is, a view along its longitudinal axis and, hence, along a straight line extending from an opening through which it is inserted. The MARVEL could be inserted through the same opening as that of the conventional endoscope, but could be adjusted to provide a view from almost any desired angle. The MARVEL camera image would be displayed, on the same monitor as that of the conventional endoscopic image, as an inset within the conventional endoscopic image. For example, while viewing a tumor from the front in the conventional endoscopic image, the surgeon could simultaneously view the tumor from the side or the rear in the MARVEL image, and could thereby gain additional visual cues that would aid in precise three-dimensional positioning of surgical tools to excise the tumor. Indeed, a side or rear view through the MARVEL could be essential in a case in which the object of surgical interest was not visible from the front. The conceptual design of the MARVEL exploits the surgeon s familiarity with endoscopic surgical tools. The MARVEL would include a miniature electronic camera and miniature radio transmitter mounted on the tip of a surgical tool derived from an endo-scissor (see figure). The inclusion of the radio transmitter would eliminate the need for wires, which could interfere with manipulation of this and other surgical tools. The handgrip of the tool would be connected to a linkage similar to that of an endo-scissor, but the linkage would be configured to enable adjustment of the camera angle instead of actuation of a scissor blade. It is envisioned that thicknesses of the tool shaft and the camera would be less than 4 mm, so that the camera-tipped tool could be swiftly inserted and withdrawn through a dime-size opening. Electronic cameras having dimensions of the order of millimeters are already commercially available, but their designs are not optimized for use in endoscopic brain surgery. The variety of potential endoscopic, thoracoscopic, and laparoscopic applications can be expected to increase as further development of electronic cameras yields further miniaturization and improvements in imaging performance.
Author
SURGERY; VISUAL STIMULI; ENDOSCOPES; IMAGING TECHNIQUES; ADJUSTING; BRAIN; VIEWING; LINE OF SIGHT
20080048206 Radiation Monitoring Devices, Inc., United States
Hard-X-Ray/Soft-Gamma-Ray Imaging Sensor Assembly for Astronomy
Myers, Richard A.; NASA Tech Briefs, September 2008; September 2008; pp. 2; In English
Report No.(s): GSC-14853-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/component/content/article/3145
An improved sensor assembly has been developed for astronomical imaging at photon energies ranging from 1 to 100 keV. The assembly includes a thallium-doped cesium iodide scintillator divided into pixels and coupled to an array of high-gain avalanche photodiodes (APDs). Optionally, the array of APDs can be operated without the scintillator to detect photons at energies below 15 keV. The array of APDs is connected to compact electronic readout circuitry that includes, among other things, 64 independent channels for detection of photons in various energy ranges, up to a maximum energy of 100 keV, at a count rate up to 3 kHz. The readout signals are digitized and processed by imaging software that performs "on-the-fly" analysis. The sensor assembly has been integrated into an imaging spectrometer, along with a pair of coded apertures (Fresnel zone plates) that are used in conjunction with the pixel layout to implement a shadow-masking technique to obtain relatively high spatial resolution without having to use extremely small pixels. Angular resolutions of about 20 arc-seconds have been measured. Thus, for example, the imaging spectrometer can be used to (1) determine both the energy spectrum of a distant x-ray source and the angular deviation of the source from the nominal line of sight of an x-ray telescope in which the spectrometer is mounted or (2) study the spatial and temporal development of solar flares, repeating - ray bursters, and other phenomena that emit transient radiation in the hard-x-ray/soft- -ray region of the electromagnetic spectrum.
Author
IMAGING TECHNIQUES; GAMMA RAYS; X RAY SOURCES; IMAGING SPECTROMETERS; ASTRONOMY; ELECTROMAGNETIC SPECTRA; HIGH RESOLUTION; HIGH GAIN
20080048207 California Inst. of Tech., Pasadena, CA, United States
Enhanced Reporting of Mars Exploration Rover Telemetry
Maimone, Mark W.; Biesiadecki, Jeffrey J.; Liebersbach, Robert T.; Carsten, Joseph L.; Leger, Chris; NASA Tech Briefs, September 2008; September 2008; pp. 6; In English; Original contains color and black and white illustrations
Report No.(s): NPO-45366; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://www.techbriefs.com/content/view/3217/34/
Mars Exploration Rover Enhanced Telemetry Extraction and Reporting System (METERS) is software that generates a human-readable representation of the state of the mobility and arm-related systems of the Mars Exploration Rover (MER) vehicles on each Martian solar day (sol). Data are received from the MER spacecraft in multiple streams having various formats including text messages, sparsely-sampled engineering quantities, images, and individual motor-command histories.
Derived from text
MARS (PLANET); TELEMETRY; ROVING VEHICLES; COMPUTER PROGRAMS; TRAJECTORY PLANNING
20080048209 NASA Marshall Space Flight Center, Huntsville, AL, United States
Sensor Applications and Data Validation
Wiley, John; July 15, 2008; In English; National Science Foundation Workshop, 15 Jul. 2008, Normal, AL, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048209
The mechanical configuration of automobiles have changed marginally while improvements in sensors and control have dramatically improved engine efficiency, reliability and useful life. The aviation industry has also taken advantage of sensors and control systems to reduce operational costs. Sensors and high fidelity control systems fly planes at levels of performance beyond human capability. Sophisticated environmental controls allow a greater level of comfort and efficiency in our homes. Sensors have given the medical field a better understanding of the human body and the environment in which we live.
Author
ENVIRONMENTAL CONTROL; AIRCRAFT INDUSTRY; OPERATING COSTS
20080048211 NASA Marshall Space Flight Center, Huntsville, AL, United States
Reusability Studies for Ares I and Ares V Propulsion
Williams, Thomas J.; Priskos, Alex S.; Schorr, Andrew A.; Barrett, Greg; July 20, 2008; In English; Joint Propulsion Conference, 20-23 Jul. 2008, Hartford, CT, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048211
With a mission to continue to support the goals of the International Space Station (ISS) and explore beyond Earth orbit, the United States National Aeronautics and Space Administration (NASA) is in the process of launching an entirely new space exploration initiative, the Constellation Program. Even as the Space Shuttle moves toward its final voyage, Constellation is building from nearly half a century of NASA spaceflight experience, and technological advances, including the legacy of Shuttle and earlier programs such as Apollo and the Saturn V rocket. Out of Constellation will come two new launch vehicles: the Ares I crew launch vehicle and the Ares V cargo launch vehicle. With the initial goal to seamlessly continue where the Space Shuttle leaves off, Ares will firstly service the Space Station. Ultimately, however, the intent is to push further: to establish an outpost on the Moon, and then to explore other destinations. With significant experience and a strong foundation in aerospace, NASA is now progressing toward the final design of the First Stage propulsion system for the Ares I. The new launch vehicle design will considerably increase safety and reliability, reduce the cost of accessing space, and provide a viable growth path for human space exploration. To achieve these goals, NASA is taking advantage of Space Shuttle hardware, safety, reliability, and experience. With efforts to minimize technical risk and life-cycle costs, the First Stage office is again pulling from NASA s strong legacy in aerospace exploration and development, most specifically the Space Shuttle Program. Trade studies have been conducted to evaluate life-cycle costs, expendability, and risk reduction. While many first stage features have already been determined, these trade studies are helping to resolve the operational requisites and configuration of the first stage element. This paper first presents an overview of the Ares missions and the genesis of the Ares vehicle design. It then looks at one of the most important trade studies to date, the "Ares I First Stage Expendability Trade Study." The purpose of this study was to determine the utility of flying the first stage as an expendable booster rather than making it reusable. To lower the study complexity, four operational scenarios (or cases) were defined. This assessment then included an evaluation of the development, reliability, performance, and transition impacts associated with an expendable solution. This paper looks at these scenarios from the perspectives of cost, reliability, and performance.
Author
ARES 1 LAUNCH VEHICLE; ARES 5 CARGO LAUNCH VEHICLE; PROPULSION; RELIABILITY; EARTH ORBITS; LIFE CYCLE COSTS
20080048217 NASA Marshall Space Flight Center, Huntsville, AL, United States
Rapid Trajectory Optimization for the ARES I Launch Vehicle
Dukeman, Greg A.; Hill, Ashley D.; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color illustrations
Copyright; Avail.: CASI: A02, Hardcopy
A simplified ascent trajectory optimization procedure has been developed with application to NASA's proposed Ares I launch vehicle. In the interest of minimizing bending loads and ensuring safe separation of the first-stage solid rocket motor, the vehicle is con- strained to follow a gravity-turn trajectory. This reduces the design space to just two free parameters, the pitch rate after a short vertical rise phase to clear the launch pad, and initial launch azimuth. The pitch rate primarily controls the in-plane parameters (altitude, speed, flight path angle) of the trajectory whereas the launch azimuth primarily controls the out-of-plane portion (velocity heading.) Thus, the optimization can be mechanized as two one-dimensional searches that converge quickly and reliably. The method is compared with POST-optimized trajectories to verify its optimality.
Author
ARES 1 LAUNCH VEHICLE; TRAJECTORY OPTIMIZATION; ASCENT TRAJECTORIES; LOADS (FORCES); FLIGHT PATHS; SOLID PROPELLANT ROCKET ENGINES
20080048228 NASA Marshall Space Flight Center, Huntsville, AL, United States
Ares I Flight Control System Overview
Hall, Charles; Lee, Chong; Jackson, Mark; Whorton, Mark; West, mark; Brandon, Jay; Hall, Rob A.; Jang, Jimmy; Bedrossian, Naz; Compton, Jimmy; Rutherford, Chad; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color illustrations
Copyright; Avail.: CASI: A02, Hardcopy
This paper describes the control challenges posed by the Ares I vehicle, the flight control system design and performance analyses used to test and verify the design. The major challenges in developing the control system are structural dynamics, dynamic effects from the powerful first stage booster, aerodynamics, first stage separation and large uncertainties in the dynamic models for all these. Classical control techniques were employed using innovative methods for structural mode filter design and an anti-drift feature to compensate for translational and rotational disturbances. This design was coded into an integrated vehicle flight simulation and tested by Monte Carlo methods. The product of this effort is a linear, robust controller design that is easy to implement, verify and test.
Author
ARES 1 LAUNCH VEHICLE; CONTROL SYSTEMS DESIGN; DYNAMIC STRUCTURAL ANALYSIS; FLIGHT SIMULATION; STRUCTURAL DESIGN; DYNAMIC MODELS; FLIGHT CONTROL
Additions to the NASA Aeronautics and Space Database as of 01/13/2009
20080048252 NASA Marshall Space Flight Center, Huntsville, AL, United States
Long-Term Effects of Soldering By-Products on Nickel-Coated Copper Wire
Rolin, T. D.; Hodge, R. E.; October 2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-215577; M-1242; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048252
An analysis of thirty-year-old, down graded flight cables was conducted to determine the makeup of a green material on the surface of the shielded wire near soldered areas and to ascertain if the green material had corroded the nickel-coated copper wire. Two likely candidates were possible due to the handling and environments to which these cables were exposed. The flux used to solder the cables is known to contain abietic acid, a carboxylic acid found in many pine rosins used for the soldering process. The resulting material copper abietate is green in color and is formed during the application of heat during soldering operations. Copper (II) chloride, which is also green in color is known to contaminate flight parts and is corrosive. Data is presented that shows the material is copper abietate, not copper (II) chloride, and more importantly that the abietate does not aggressively attack nickel-plated copper wire.
Author
COATINGS; COPPER CHLORIDES; NICKEL; SOLDERING; CORROSION
20080048254 NASA Marshall Space Flight Center, Huntsville, AL, United States
Analysis of Ares 1 Ascent Navigation Options
Norris, Lee; Tao, Yee-Chee; Hall, Robert; Chuang, Jason; Whorton, Mark; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
The paper documents a collaborative analysis of ascent Navigation options for the Ares 1 launch vehicle by the NASA Marshall Space Flight Center (MSFC) and the C. S. Draper Laboratory. The objective of the work was the development of a Navigation concept and supporting requirements which meet the Ares 1 accuracy specification in a manner which is straightforward, reliable, and cost effective. Six primary Navigation architectures were considered. In each case analysis was performed to determine under what conditions the required accuracy at second stage cutoff could be achieved. Those architectures which met the accuracy requirements were then assessed in terms of cost, complexity, and reliability to determine a baseline Navigation approach and the primary supporting requirements.
Author
ARES 1 LAUNCH VEHICLE; ASCENT; NAVIGATION; RELIABILITY; ACCURACY
20080048258 NASA Langley Research Center, Hampton, VA, United States
Experimental Investigation of Project Orion Crew Exploration Vehicle Aeroheating in AEDC Tunnel 9
Hollis, Brian R.; Horvath, Thomas J.; Berger, Karen T.; Lillard, Randolph P.; Kirk, Benjamin S.; Coblish, Joseph J.; Norris, Joseph D.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 644423.02.39.04.10.03
Report No.(s): NASA/TP-2008-215547; L-19359; No Copyright; Avail.: CASI: A08, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048258
An investigation of the aeroheating environment of the Project Orion Crew Entry Vehicle has been performed in the Arnold Engineering Development Center Tunnel 9. The goals of this test were to measure turbulent heating augmentation levels on the heat shield and to obtain high-fidelity heating data for assessment of computational fluid dynamics methods. Laminar and turbulent predictions were generated for all wind tunnel test conditions and comparisons were performed with the data for the purpose of helping to define uncertainty margins for the computational method. Data from both the wind tunnel test and the computational study are presented herein.
Author
AERODYNAMIC HEATING; CREW EXPLORATION VEHICLE; COMPUTATIONAL FLUID DYNAMICS; HEAT SHIELDING; TURBULENCE
20080048260 NASA Langley Research Center, Hampton, VA, United States
Review of Tm and Ho Materials; Spectroscopy and Lasers
Walsh, Brian M.; June 30, 2008; In English; International Laser Physics Workshop, 30 Jun. - 4 Jul. 2008, Trondheim, Norway; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 698671.01.07.09
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048260
A review of Tm and Ho materials is presented, covering some fundamental aspects on the spectroscopy and laser dynamics in both single and co-doped systems. Following an introduction to 2- m lasers, applications and historical development, the physics of quasi-four level lasers, energy transfer and modeling are discussed in some detail. Recent developments in using Tm lasers to pump Ho lasers are discussed, and seen to offer some advantages over conventional Tm:Ho lasers. This article is not intended as a complete review, but as a primer for introducing concepts and a resource for further study.
Author
LASERS; ENERGY TRANSFER; DOPED CRYSTALS; HOLMIUM; THULIUM
20080048262 NASA Langley Research Center, Hampton, VA, United States
Radiometric Modeling and Calibration of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS)Ground Based Measurement Experiment
Tian, Jialin; Smith, William L.; Gazarik, Michael J.; November 17, 2008; In English; SPIE Asia Pacific Remote Sensing 2008, 17-21 Nov. 2008, Noumea, New Caledonia; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 921266.04.07.07.01
Report No.(s): Paper Number 7149-13; Copyright; Avail.: CASI: A02, Hardcopy
The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere s thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The GIFTS calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts, therefore, enhancing the absolute calibration accuracy. This method is applied to data collected during the GIFTS Ground Based Measurement (GBM) experiment, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The accurately calibrated GIFTS radiances are produced using the first four PC scores in the GIFTS-AERI regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period. Using the GIFTS GBM calibration model, we compute the calibrated radiances from data collected during the moon tracking and viewing experiment events. From which, we derive the lunar surface temperature and emissivity associated with the moon viewing measurements.
Author
GEOSYNCHRONOUS ORBITS; REMOTE SENSING; HIGH RESOLUTION; RADIOSONDES; GREENHOUSE EFFECT; INFRARED SPECTROMETERS; MATHEMATICAL MODELS
20080048263 NASA Marshall Space Flight Center, Huntsville, AL, United States
Development of a Smooth Trajectory Maneuver Method to Accommodate the Ares I Flight Control Constraints
Pinson, Robin M.; Schmitt, Terri L.; Hanson, John M.; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048263
Six degree-of-freedom (DOF) launch vehicle trajectories are designed to follow an optimized 3-DOF reference trajectory. A vehicle has a finite amount of control power that it can allocate to performing maneuvers. Therefore, the 3-DOF trajectory must be designed to refrain from using 100% of the allowable control capability to perform maneuvers, saving control power for handling off-nominal conditions, wind gusts and other perturbations. During the Ares I trajectory analysis, two maneuvers were found to be hard for the control system to implement; a roll maneuver prior to the gravity turn and an angle of attack maneuver immediately after the J-2X engine start-up. It was decided to develop an approach for creating smooth maneuvers in the optimized reference trajectories that accounts for the thrust available from the engines. A feature of this method is that no additional angular velocity in the direction of the maneuver has been added to the vehicle after the maneuver completion. This paper discusses the equations behind these new maneuvers and their implementation into the Ares I trajectory design cycle. Also discussed is a possible extension to adjusting closed-loop guidance.
Author
ARES 1 LAUNCH VEHICLE; TRAJECTORY ANALYSIS; FEEDBACK CONTROL; DEGREES OF FREEDOM; CONTROLLABILITY; ANGLE OF ATTACK; FLIGHT CONTROL
20080048264 NASA Marshall Space Flight Center, Huntsville, AL, United States
Orbital Express Advanced Video Guidance Sensor: Ground Testing, Flight Results and Comparisons
Pinson, Robin M.; Howard, Richard T.; Heaton, Andrew F.; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048264
Orbital Express (OE) was a successful mission demonstrating automated rendezvous and docking. The 2007 mission consisted of two spacecraft, the Autonomous Space Transport Robotic Operations (ASTRO) and the Next Generation Serviceable Satellite (NEXTSat) that were designed to work together and test a variety of service operations in orbit. The Advanced Video Guidance Sensor, AVGS, was included as one of the primary proximity navigation sensors on board the ASTRO. The AVGS was one of four sensors that provided relative position and attitude between the two vehicles. Marshall Space Flight Center was responsible for the AVGS software and testing (especially the extensive ground testing), flight operations support, and analyzing the flight data. This paper briefly describes the historical mission, the data taken on-orbit, the ground testing that occurred, and finally comparisons between flight data and ground test data for two different flight regimes.
Author
ATTITUDE (INCLINATION); SPACECRAFT DOCKING; ORBITAL RENDEZVOUS; NAVIGATION INSTRUMENTS; GUIDANCE SENSORS; FLIGHT TESTS; AUTONOMY
20080048265 NASA Marshall Space Flight Center, Huntsville, AL, United States
How Might the Ares V Change the Need for Future Mirror Technology
Stahl, H. Philip; August 25, 2008; In English; 8th Annual Mirror Technology Days in the Government, 25-27 Aug. 2008, Albuquerque, NM, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048265
More Massive Missions do not need to be More Expensive. Simple, robust, low-risk, high-TRL mission is likely to be low cost. It is also likely to be more massive than a complex, high-risk, low TRL mission. The challenge will be to overcome human nature. Launch Date Constrained Missions Cost Less
Author
LOW COST; ARES 5 CARGO LAUNCH VEHICLE; COSTS
20080048266 NASA Marshall Space Flight Center, Huntsville, AL, United States
Integrated Safety Analysis Teams
Wetherholt, Jonathan C.; August 25, 2008; In English; System Safety Society, 25-29 Aug. 2008, Vancouver, BC, Canada; Original contains color illustrations
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20080048266
Today's complex systems require understanding beyond one person s capability to comprehend. Each system requires a team to divide the system into understandable subsystems which can then be analyzed with an Integrated Hazard Analysis. The team must have both specific experiences and diversity of experience. Safety experience and system understanding are not always manifested in one individual. Group dynamics make the difference between success and failure as well as the difference between a difficult task and a rewarding experience. There are examples in the news which demonstrate the need to connect the pieces of a system into a complete picture. The Columbia disaster is now a standard example of a low consequence hazard in one part of the system; the External Tank is a catastrophic hazard cause for a companion subsystem, the Space Shuttle Orbiter. The interaction between the hardware, the manufacturing process, the handling, and the operations contributed to the problem. Each of these had analysis performed, but who constituted the team which integrated this analysis together? This paper will explore some of the methods used for dividing up a complex system; and how one integration team has analyzed the parts. How this analysis has been documented in one particular launch space vehicle case will also be discussed.
Author
COMPLEX SYSTEMS; LAUNCH VEHICLES; GROUP DYNAMICS; SAFETY; SPACE SHUTTLE ORBITERS
20080048307 QSS Group, Inc., Cleveland, OH, United States
User's Manual for LEWICE Version 3.2
Wright, William; November 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS3-00145WBS 75280.02.07.03.02
Report No.(s): NASA/CR-2008-214255; E-15537; Copyright; Avail.: CASI: A20, Hardcopy
A research project is underway at NASA Glenn to produce a computer code which can accurately predict ice growth under a wide range of meteorological conditions for any aircraft surface. This report will present a description of the code inputs and outputs from version 3.2 of this software, which is called LEWICE. This version differs from release 2.0 due to the addition of advanced thermal analysis capabilities for de-icing and anti-icing applications using electrothermal heaters or bleed air applications, the addition of automated Navier-Stokes analysis, an empirical model for supercooled large droplets (SLD) and a pneumatic boot option. An extensive effort was also undertaken to compare the results against the database of electrothermal results which have been generated in the NASA Glenn Icing Research Tunnel (IRT) as was performed for the validation effort for version 2.0. This report will primarily describe the features of the software related to the use of the program. Appendix A has been included to list some of the inner workings of the software or the physical models used. This information is also available in the form of several unpublished documents internal to NASA. This report is intended as a replacement for all previous user manuals of LEWICE. In addition to describing the changes and improvements made for this version, information from previous manuals may be duplicated so that the user will not need to consult previous manuals to use this software.
Author
ICE FORMATION; THERMAL ANALYSIS; DEICING; USER MANUALS (COMPUTER PROGRAMS); AIRCRAFT ICING; COMPUTER PROGRAMS; HEAT TRANSFER
20080048309 NASA Langley Research Center, Hampton, VA, United States; Raytheon Co., Hampton, VA, United States
Wake Turbulence Mitigation for Departures (WTMD) Prototype System - Software Design Document
Sturdy, James L.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): L70750DWBS 305295.02.07.07.20
Report No.(s): NASA/CR-2008-215549; CONITS-TP-139; Copyright; Avail.: CASI: A09, Hardcopy
This document describes the software design of a prototype Wake Turbulence Mitigation for Departures (WTMD) system that was evaluated in shadow mode operation at the Saint Louis (KSTL) and Houston (KIAH) airports. This document describes the software that provides the system framework, communications, user displays, and hosts the Wind Forecasting Algorithm (WFA) software developed by the M.I.T. Lincoln Laboratory (MIT-LL). The WFA algorithms and software are described in a separate document produced by MIT-LL.
Author
AIRPORTS; WAKES; SOFTWARE ENGINEERING; DISPLAY DEVICES; FORECASTING
Additions to the NASA Aeronautics and Space Database as of 01/16/2009
20090000975 NASA Johnson Space Center, Houston, TX, United States
NASA Johnson Space Center's Energy and Sustainability Efforts
Ewert, Michael K.; September 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): 439906
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090000975
This viewgraph presentation reviews the efforts that NASA is making to assure a sustainable environment and energy savings at the Johnson Space Center. Sustainability is defined as development that meets the needs of present generations without compromising the ability of future generations to meet their own needs. The new technologies that are required for sustainable closed loop life support for space exploration have uses on the ground to reduce energy, greenhouse gas emissions, and water use. Some of these uses are reviewed.
CASI
ENERGY CONSERVATION; EXHAUST EMISSION; HABITABILITY; ENVIRONMENTS; ENERGY POLICY; TECHNOLOGY UTILIZATION; NASA PROGRAMS
20090000977 NASA Marshall Space Flight Center, Huntsville, AL, United States
Ares Launch Vehicles Lean Practices Case Study
Doreswamy, Rajiv, N.; Self, Timothy A.; March 2008; In English; IEEE Aerospace Conference, 1-8 Mar. 2008, Big Sky, MT, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090000977
This viewgraph presentation describes test strategies and lean philisophies and practices that are applied to Ares Launch Vehicles. The topics include: 1) Testing strategy; 2) Lean Practices in Ares I-X; 3) Lean Practices Applied to Ares I-X Schedule; 4) Lean Event Results; 5) Lean, Six Sigma, and Kaizen Practices in the Ares Projects Office; 6) Lean and Kaizen Success Stories; and 7) Ares Six Sigma Practices.
CASI
ARES 1 LAUNCH VEHICLE; PROJECT PLANNING; SPACE EXPLORATION; NASA SPACE PROGRAMS
20090000978 NASA Marshall Space Flight Center, Huntsville, AL, United States
On the Observed Robustness of Disturbance-Observers; A Technical Explanation and Simulation Validation
Hannan, Michael R.; March 16, 2008; In English; Southeastern Symposium on System Theory, 16-18 Mar. 2008, New Orleans, LA, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090000978
This paper examines the ability of a real-time "disturbance-observer" to adapt-to and closely estimate the time-behavior of a disturbance-input w(t) (and of it's state-vector z(t)) even when the actual w(t) time-behavior deviates from the observer's "internal-copy" of the nominal/predicted w(t)-behavior. By means of technical explanations and confirming simulation studies of numerical examples, the disturbance-observer's adaptive ability is explained in terms-of the underlying spline-model used to derive the disturbance state-model and the intrinsic dynamic characteristics of a state-observer.
Author
SIMULATION; MATHEMATICAL MODELS; DYNAMICAL SYSTEMS; PERTURBATION THEORY; ROBUSTNESS (MATHEMATICS)
Additions to the NASA Aeronautics and Space Database as of 01/19/2009
20090001144 NASA Dryden Flight Research Center, Edwards, CA, United States
F-15 IFCS Intelligent Flight Control System
Bosworth, John T.; October 23, 2008; In English; Workshop on Adaptive Controls Technology Assessment, 23-24 Oct. 2008, Denver, CO, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001144
This viewgraph presentation gives a detailed description of the F-15 aircraft, flight tests, aircraft performance and overall advanced neural network based flight control technologies for aerospace systems designs.
CASI
AEROSPACE SYSTEMS; F-15 AIRCRAFT; FLIGHT CONTROL; CONTROL SYSTEMS DESIGN; NEURAL NETS; FULL SCALE TESTS
20090001147 NASA Dryden Flight Research Center, Edwards, CA, United States
Western Aeronautical Test Range
Sakahara, Robert D.; November 18, 2008; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001147
This viewgraph presentation reviews the work of the Western Aeronautical Test Range (WATR). NASA's Western Aeronautical Test Range is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). Maps show the general location of the WATR area that is used for aeronautical testing and evaluation. The products, services and facilities of WATR are discussed,
CASI
ORGANIZATIONS; TEST RANGES; AERONAUTICS; NASA PROGRAMS
20090001151 NASA Marshall Space Flight Center, Huntsville, AL, United States
Orbital Express Advanced Video Guidance Sensor
Howard, Ricky; Heaton, Andy; Pinson, Robin; Carrington, Connie; March 2008; In English; 2008 IEEE Aerospace Conference, 1-8 Mar. 2008, Big Sky, MT, United States
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001151
In May 2007 the first US fully autonomous rendezvous and capture was successfully performed by DARPA's Orbital Express (OE) mission. Since then, the Boeing ASTRO spacecraft and the Ball Aerospace NEXTSat have performed multiple rendezvous and docking maneuvers to demonstrate the technologies needed for satellite servicing. MSFC's Advanced Video Guidance Sensor (AVGS) is a primary near-field proximity operations sensor integrated into ASTRO's Autonomous Rendezvous and Capture Sensor System (ARCSS), which provides relative state knowledge to the ASTRO GN&C system. This paper provides an overview of the AVGS sensor flying on Orbital Express, and a summary of the ground testing and on-orbit performance of the AVGS for OE. The AVGS is a laser-based system that is capable of providing range and bearing at midrange distances and full six degree-of-freedom (6DOF) knowledge at near fields. The sensor fires lasers at two different frequencies to illuminate the Long Range Targets (LRTs) and the Short Range Targets (SRTs) on NEXTSat. Subtraction of one image from the other image removes extraneous light sources and reflections from anything other than the corner cubes on the LRTs and SRTs. This feature has played a significant role for Orbital Express in poor lighting conditions. The very bright spots that remain in the subtracted image are processed by the target recognition algorithms and the inverse-perspective algorithms, to provide 3DOF or 6DOF relative state information. Although Orbital Express has configured the ASTRO ARCSS system to only use AVGS at ranges of 120 m or less, some OE scenarios have provided opportunities for AVGS to acquire and track NEXTSat at greater distances. Orbital Express scenarios to date that have utilized AVGS include a berthing operation performed by the ASTRO robotic arm, sensor checkout maneuvers performed by the ASTRO robotic arm, 10-m unmated operations, 30-m unmated operations, and Scenario 3-1 anomaly recovery. The AVGS performed very well during the pre-unmated operations, effectively tracking beyond its 10-degree Pitch and Yaw limit-specifications, and did not require I-LOAD adjustments before unmated operations. AVGS provided excellent performance in the 10-m unmated operations, effectively tracking and maintaining lock for the duration of this scenario, and showing good agreement between the short and long range targets. During the 30-m unmated operations, the AVGS continuously tracked the SRT to 31.6 m, exceeding expectations, and continuously tracked the LRT from 8.8 m out to 31.6 m, with good agreement between these two target solutions. After this scenario was aborted at a 10-m separation during remate operations, the AVGS tracked the LRT out 54.3 m, until the relative attitude between the vehicles was too large. The vehicles remained apart for eight days, at ranges from 1 km to 6 km. During the approach to remate in this recovery operation, the AVGS began tracking the LRT at 150 m, well beyond the OE planned limits for AVGS ranges, and functioned as the primary sensor for the autonomous rendezvous and docking.
Author
GUIDANCE SENSORS; ORBITAL RENDEZVOUS; VIDEO COMMUNICATION; SPACE MISSIONS; ROBOTICS; AUTONOMOUS DOCKING; ASTRO VEHICLE
20090001152 NASA Marshall Space Flight Center, Huntsville, AL, United States
"Built-In" Action/Issues Tracking and Post-Ops Analysis Tool for Realtime Console Operations
Scott, David W.; March 2008; In English; 2008 IEEE Aerospace Conference, 1-8 mar. 2008, Big Sky, MT, United States
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001152
Marshall Space Flight Center's (MSFC) Payload Operations Integration Center (POIC) for the International Space Station (ISS) uses a number of formal databases to manage and track flight plan changes, onboard and ground equipment anomalies, and other events. However, individual console positions encounter many action items and/or occurrences that don't fit neatly into the databases, and while console logs are comprehensive, manual or automated searches do not always yield consistent results. The Payload Communications Manager (PAYCOM) team, whose members speak directly with the ISS onboard crew with respect to NASA payload operations, has found a creative way to reformat a mandatory Daily Report to organize action items, standing reminders, significant events, and other comments. While the report keeps others appraised of PAYCOMs activities and issues of the moment, the format makes it easy to capture very brief summaries of the items in a "Roll Off Matrix", including start and stop dates, resolution, and possible applicability to future ops. The matrix provides accountability for all action items, gives direct insight into the issues surrounding various payloads and methods of dealing with them, yields indirect information on PAYCOM priorities and processes, and provides a roadmap that makes it easier to get back to extensive details if needed. This paper describes how the ISS PAYCOM Daily Report and Roll Off Matrix are organized, used, and inter-related to each other and the PAYCOM operations log. While the application is for a manned vehicle, the concepts could apply in a wide spectrum of operational settings.
Author
CONSOLES; INTERNATIONAL SPACE STATION; PAYLOAD INTEGRATION; REAL TIME OPERATION; FLIGHT OPERATIONS; SPACECRAFT COMMUNICATION
20090001157 NASA White Sands Test Facility, NM, United States
Effect of Oxygen Concentration on Autogenous Ignition Temperature and Pneumatic Impact Ignitability of Nonmetallic Materials
Smith, Sarah; [2009]; In English; 12th International Symposium on Materials in Oxygen-Enriched Atmospheres, 7-0 Oct. 2009, Berlin, Germany; Original contains black and white illustrations
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001157
Extensive test data exist on the ignitability of nonmetallic materials in pure oxygen, but these characteristics are not as well understood for lesser oxygen concentrations. In this study, autogenous ignition temperature testing and pneumatic impact testing were used to better understand the effects of oxygen concentration on ignition of nonmetallic materials. Tests were performed using oxygen concentrations of 21, 34, 45, and 100 %. The following materials were tested: PTFE Teflon(Registered Trademark), Buna-N, Silicone, Zytel(Registered Trademark) 42, Viton(registered Trademark) A, and Vespel(Registered Trademark) SP-21.
Author
IGNITION TEMPERATURE; POLYTETRAFLUOROETHYLENE; SILICONES; BUNA (TRADEMARK); IGNITION; OXYGEN
20090001165 NASA Marshall Space Flight Center, Huntsville, AL, United States
Analysis and Design of Launch Vehicle Flight Control Systems
Wie, Bong; Du, Wei; Whorton, Mark; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
This paper describes the fundamental principles of launch vehicle flight control analysis and design. In particular, the classical concept of "drift-minimum" and "load-minimum" control principles is re-examined and its performance and stability robustness with respect to modeling uncertainties and a gimbal angle constraint is discussed. It is shown that an additional feedback of angle-of-attack or lateral acceleration can significantly improve the overall performance and robustness, especially in the presence of unexpected large wind disturbance. Non-minimum-phase structural filtering of "unstably interacting" bending modes of large flexible launch vehicles is also shown to be effective and robust.
Author
LAUNCH VEHICLES; FLIGHT CONTROL; STABILITY; BENDING; ANGLE OF ATTACK; ROBUSTNESS (MATHEMATICS)
20090001166 NASA Stennis Space Center, Stennis Space Center, MS, United States
Computational Analyses in Support of Sub-scale Diffuser Testing for the A-3 Facility Part 2 Unsteady Analyses and Risk Assessment
Ahuja, Vineet; Hosangadi, Ashvin; Allgood, Daniel; [2008]; In English; Original contains color illustrations
Contract(s)/Grant(s): NNX08CA36C
Report No.(s): SSTI-8080-0024; Copyright; Avail.: CASI: A01, Hardcopy
Simulation technology can play an important role in rocket engine test facility design and development by assessing risks, providing analysis of dynamic pressure and thermal loads, identifying failure modes and predicting anomalous behavior of critical systems. This is especially true for facilities such as the proposed A-3 facility at NASA SSC because of a challenging operating envelope linked to variable throttle conditions at relatively low chamber pressures. Design Support of the feasibility of operating conditions and procedures is critical in such cases due to the possibility of startup/shutdown transients, moving shock structures, unsteady shock-boundary layer interactions and engine and diffuser unstart modes that can result in catastrophic failure. Analyses of such systems is difficult due to resolution requirements needed to accurately capture moving shock structures, shock-boundary layer interactions, two-phase flow regimes and engine unstart modes. In a companion paper, we will demonstrate with the use of CFD, steady analyses advanced capability to evaluate supersonic diffuser and steam ejector performance in the sub-scale A-3 facility. In this paper we will address transient issues with the operation of the facility especially at startup and shutdown, and assess risks related to afterburning due to the interaction of a fuel rich plume with oxygen that is a by-product of the steam ejectors. The primary areas that will be addressed in this paper are: (1) analyses of unstart modes due to flow transients especially during startup/ignition, (2) engine safety during the shutdown process (3) interaction of steam ejectors with the primary plume i.e. flow transients as well as probability of afterburning. In this abstract we discuss unsteady analyses of the engine shutdown process. However, the final paper will include analyses of a staged startup, drawdown of the engine test cell pressure, and risk assessment of potential afterburning in the facility. Unsteady simulations have been carried out to study the engine shutdown process in the facility and understand the physics behind the interactions between the steam ejectors, the test cell and the supersonic diffuser. As a first approximation, to understand the dominant unsteady mechanisms in the engine test cell and the supersonic diffuser, the turning duct in the facility was removed. As the engine loses power a rarefaction wave travels downstream that disrupts the shock cell structure in the supersonic diffuser. Flow from the test cell is seen to expand into the supersonic diffuser section and re-pressurizes the area around the nozzle along with a upstream traveling compression wave that emanates from near the first stage ejectors. Flow from the first stage ejector expands to the center of the duct and a new shock train is formed between the first and second stage ejectors. Both stage ejectors keep the facility pressurized and prevent any large amplitude pressure fluctuations from affecting the engine nozzle. The resultant pressure loads the nozzle experiences in the shutdown process are small.
Author
COMPUTATIONAL FLUID DYNAMICS; DYNAMIC PRESSURE; ROCKET ENGINE DESIGN; PRESSURE OSCILLATIONS; PROBABILITY THEORY; RISK ASSESSMENT; SHOCK WAVE INTERACTION; SUPERSONIC DIFFUSERS
Additions to the NASA Aeronautics and Space Database as of 01/20/2009
20090001228 NASA Johnson Space Center, Houston, TX, United States
Lunar Dust and Lunar Simulant Activation, Monitoring, Solution and Cellular Toxicity Properties
Jeevarajan, A.S.; Wallace, W.T.; [2009]; In English; Human Research Program Investigators Workshop, 2 - 4 Feb. 2009, Texas, United States
Copyright; Avail.: CASI: A01, Hardcopy
During the Apollo missions, many undesirable situations were encountered that must be mitigated prior to returning humans to the moon. Lunar dust (that part of the lunar regolith less than 20 m in diameter) was found to produce several problems with astronaut s suits and helmets, mechanical seals and equipment, and could have conceivably produced harmful physiological effects for the astronauts. For instance, the abrasive nature of the dust was found to cause malfunctions of various joints and seals of the spacecraft and suits. Additionally, though efforts were made to exclude lunar dust from the cabin of the lunar module, a significant amount of material nonetheless found its way inside. With the loss of gravity correlated with ascent of the lunar module from the lunar surface to rendezvous with the command module, much of the major portions of the contaminating soil and dust began to float, irritating the astronaut s eyes and being inhaled into their lungs. Our goal has been to understand some of the properties of lunar dust that could lead to possible hazards for humans. Due to the lack of an atmosphere, there is nothing to protect the lunar soil from ultraviolet radiation, solar wind, and meteorite impacts. These processes could all serve to activate the soil, or produce reactive surface species. In order to understand the possible toxic effects of the reactive dust, it is necessary to reactivate the dust, as samples returned during the Apollo missions were exposed to the atmosphere of the Earth. We have used grinding and UV exposure to mimic some of the processes occurring on the Moon. The level of activation has been monitored using two methods: fluorescence spectroscopy and electron paramagnetic resonance spectroscopy (EPR). These techniques allow the monitoring of hydroxyl radical production in solution. We have found that grinding of lunar dust produces 2-3 times the concentration of hydroxyl radicals as lunar simulant and 10 times that of quartz. Exposure of the lunar dust to UV radiation under vacuum was also found to lead to hydroxyl radical production. After grinding, we have also monitored loss of reactivity of the dusts by exposing them to conditions of known humidity and temperature. From these tests, it was found that the reactivity half-life of lunar simulant is approximately 3 hours, while that of quartz is approximately 2 hours. Placing lunar dust in solution could lead to effects on mechanical and physiological systems, as well as other biological systems. For instance, while it is known that lunar dust is highly abrasive and caused a variety of problems with suits and equipment during Apollo, it is unknown as to how these properties might be affected in the presence of water or other liquids. It is possible that the dust may release minerals (e.g., metallic nanophase Fe) into solution that could speed corrosion or rust. Also, as lunar dust produces hydroxyl radicals (and possibly other reactive oxygen species) in solution, these radicals could also lead to the breakdown of suit or habitat materials. In the body (i.e., in lung solution), the effects could be two-fold. First, if the lunar dust dissolves, it may release an excess of elements (such as zero-valence metallic Fe) that are necessary for bodily functions but only in certain concentration ranges. For lunar dust, the presence of nanophase iron being released into the body is a concern. Secondly, the hydroxyl radicals or other reactive oxygen species produced by the dust in solution could conceivably interact with cells, leading to various problems. We have studied the dissolution of both ground and unground lunar simulant in buffer solutions of different pH. The concentration of a number of species was determined using mass spectrometry. These studies showed that lowering the pH of the solution causes a dramatic increase in the amount of each element released into solution and that grinding also produces higher concentrations. Finally, we have perfmed initial tests aimed at understanding the effects of lunar simulant on cellular systems. Alveolar epithelial cells were cultured and exposed to different concentrations of dust suspended in cell culture media. After predetermined amounts of time, the media was removed and the concentrations of important inflammatory cytokines (IL6, IL8, and TNF-alpha ) were measured. The results of these tests are being used to develop the correct protocols for tests to be performed using lunar dust samples.
Author
LUNAR DUST; LUNAR SOIL; TOXICITY; CELLS (BIOLOGY); REGOLITH; LUNAR ROCKS; ELECTRON PARAMAGNETIC RESONANCE
20090001229 NASA Langley Research Center, Hampton, VA, United States
Cross Sections From Scalar Field Theory
Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel; December 2008; In English; Original contains black and white illustrations
Report No.(s): NASA/TP-2008-215555; L-19558; Copyright; Avail.: CASI: A04, Hardcopy
A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.
Author
SCALARS; SCATTERING CROSS SECTIONS; NUCLEONS; PIONS
20090001232 CUBRC, Inc., Buffalo, NY, United States
Experimental Studies of the Aerothermal Characteristics of the Project Orion CEV heat Shield in High Speed Transitional and Turbulent Flows
Wadhams, T.P.; MacLean, M.; Holden, M.S.; Cassady, A.M.; [2009]; In English; 47th AIAA Aerospace Sciences Meeting, 5 - 8 Jan. 2009, Florida, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
An experimental program has been completed by CUBRC exploring laminar, transitional, and turbulent flows over a 7.0% scale model of the Project ORION CEV geometry. This program was executed primarily to answer questions concerning the increase in heat transfer on the windward, or "hot shoulder" of the CEV heat shield from laminar to turbulent flow. To answer these questions CUBRC constructed and instrumented a 14.0 inch diameter Project ORION CEV model and ran a range of Reynolds numbers based on diameter from 1.0 to over 40 million at a Mach number of 8.0. These Reynolds numbers were selected to cover laminar to turbulent heating data on the "hot shoulder". Data obtained during these runs will be used to guide design decisions as they apply to heat shield thickness and extent. Several experiments at higher enthalpies were achieved to obtain data for code validation with real gas effects and transition. CUBRC also performed computation studies of these experiments to aid in the data reduction process and study turbulence modeling.
Author
TURBULENT FLOW; LAMINAR FLOW; HIGH SPEED; HEAT SHIELDING; CREW EXPLORATION VEHICLE; HEAT TRANSFER; TURBULENCE MODELS
20090001234 NASA Johnson Space Center, Houston, TX, United States
Direct Multiple Shooting Optimization with Variable Problem Parameters
Whitley, Ryan J.; Ocampo, Cesar A.; [2009]; In English; 47th AIAA Aerospace Sciences Meeting, 5 - 8 Jan. 2009, Florida, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Taking advantage of a novel approach to the design of the orbital transfer optimization problem and advanced non-linear programming algorithms, several optimal transfer trajectories are found for problems with and without known analytic solutions. This method treats the fixed known gravitational constants as optimization variables in order to reduce the need for an advanced initial guess. Complex periodic orbits are targeted with very simple guesses and the ability to find optimal transfers in spite of these bad guesses is successfully demonstrated. Impulsive transfers are considered for orbits in both the 2-body frame as well as the circular restricted three-body problem (CRTBP). The results with this new approach demonstrate the potential for increasing robustness for all types of orbit transfer problems.
Author
THREE BODY PROBLEM; TRANSFER ORBITS; GRAVITATIONAL CONSTANT; ANALYSIS (MATHEMATICS)
20090001236 NASA, Washington, DC, United States
William H. Pickering: America's Deep Space Pioneer
Mudgway, Douglas J.; October 2008; In English; Original contains black and white illustrations
Report No.(s): NASA-SP-2008-4113; No Copyright; Avail.: CASI: EA5, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001236
William Pickering first came to the attention of the world in January 1958 when the media triumphantly announced the successful launch of Explorer 1, the American response to the Soviet deployment a few months earlier of the first Earth-orbiting satellite Sputnik. Along with Wernher von Braun and James Van Allen, William Pickering shared the limelight and the accolades. In that instant of time the Space Age was born and with it the professional reputation of William H. Pickering. Under Pickering's leadership, JPL designed, built, and dispatched NASA's first Ranger spacecraft to take close-up pictures of the surface of the Moon. Building on its Ranger experience, JPL sent the first spacecraft to Venus and, as technology improved, to Mars. The scientific data returns from each successive mission greatly increased our understanding of the composition and dynamics of the solar system and its planets. When he retired as Director in 1976, Pickering had presided over NASA-JPL's missions to the Moon, Venus, and Mars and laid the basis for the fabulous Voyager Grand Tour of all the planets that would sound the praises of NASA-JPL for the next 25 years. Not all of the missions were successful, but Pickering accepted the responsibility that devolved from his position as Director, regardless of the outcome.
Derived from text
NASA PROGRAMS; SPACE EXPLORATION; LEADERSHIP; BIOGRAPHY; HISTORIES; SCIENTISTS; RESEARCH AND DEVELOPMENT; PROJECT MANAGEMENT; ASTRONAUTICS
20090001264 NASA Dryden Flight Research Center, Edwards, CA, United States
NASA Global Hawk: Project Update and Future Missions
Naftel, J. Chris; November 20, 2008; In English; 17th William T. Pecora Memorial Remote Sensing Symposium, 16-20 Nov. 2008, Denver, CO, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001264
The USAF transferred ownership of two pre-production Global Hawk aircraft to NASA Dryden in September 2007. Both aircraft have low flight hours and they were transferred to NASA with most of the equipment required for flight. NASA Dryden and Northrop Grumman have developed a partnership for standing up the capability over 1 year, operating the system for 4 years, and sharing use of the assets. The agreement was signed in April 2008. NASA Dryden will focus on Earth Science missions and Northrop Grumman will focus on DoD and internal company payload and system developments.
Author
SYNTHETIC APERTURE RADAR; PAYLOADS; PODS (EXTERNAL STORES); WINGS; COMMAND AND CONTROL; FLIGHT OPERATIONS; COMMUNICATION SATELLITES; AIR TRAFFIC CONTROL
20090001281 NASA Marshall Space Flight Center, Huntsville, AL, United States
Performance Assessment of the Exploration Water Recovery System
Carter. D. Layne; Tabb, David; Perry, Jay; June 30, 2008; In English; 38th International Conference on Environmental Systems, 30 Jun. - 2 Jul. 2008, San Francisco, CA, United States; Original contains color and black and white illustrations
Report No.(s): 2008-01-0042; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001281
A new water recovery system architecture designed to fulfill the National Aeronautics and Space Administration s (NASA) Space Exploration Policy has been tested at the Marshall Space Flight Center (MSFC). This water recovery system architecture evolved from the current state-of-the-art system developed for the International Space Station (ISS). Through novel integration of proven technologies for air and water purification, this system promises to elevate existing system optimization. The novel aspect of the system is twofold. First, volatile organic compounds (VOC) are removed from the cabin air via catalytic oxidation in the vapor phase, prior to their absorption into the aqueous phase. Second, vapor compression distillation (VCD) technology processes the condensate and hygiene waste streams in addition to the urine waste stream. Oxidation kinetics dictate that removing VOCs from the vapor phase is more efficient. Treating the various waste streams by VCD reduces the load on the expendable ion exchange and adsorption media which follows, as well as the aqueous-phase catalytic oxidation process further downstream. This paper documents the results of testing this new architecture.
Author
WATER RECLAMATION; TECHNOLOGY ASSESSMENT; PERFORMANCE; NASA PROGRAMS; INTERNATIONAL SPACE STATION; DESIGN OPTIMIZATION; AEROSPACE ENGINEERING
20090001282 NASA Marshall Space Flight Center, Huntsville, AL, United States
On Alfvenic Waves and Stochastic Ion Heating with 1Re Observations of Strong Field-aligned Currents, Electric Fields, and O+ ions
Coffey, Victoria; Chandler, Michael; Singh, Nagendra; July 13, 2008; In English; 37th COSPAR Scientific Assembly, 13-20 Jul. 2008, Montreal, Canada; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
The role that the cleft/cusp has in ionosphere/magnetosphere coupling makes it a very dynamic region having similar fundamental processes to those within the auroral regions. With Polar passing through the cusp at 1 Re in the Spring of 1996, we observe a strong correlation between ion heating and broadband ELF (BBELF) emissions. This commonly observed relationship led to the study of the coupling of large field-aligned currents, burst electric fields, and the thermal O+ ions. We demonstrate the role of these measurements to Alfvenic waves and stochastic ion heating. Finally we will show the properties of the resulting density cavities.
Author
MAGNETOHYDRODYNAMIC WAVES; STOCHASTIC PROCESSES; PLASMA HEATING; IONS; FIELD ALIGNED CURRENTS; ELECTRIC FIELDS
20090001283 NASA Marshall Space Flight Center, Huntsville, AL, United States
Mission Assessment of the Faraday Accelerator with Radio-frequency Assisted Discharge (FARAD)
Dankanich, John W.; Polzin, Kurt A.; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford,CT, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Pulsed inductive thrusters have typically been considered for future, high-power, missions requiring nuclear electric propulsion. These high-power systems, while promising equivalent or improved performance over state-of-the-art propulsion systems, presently have no planned missions for which they are well suited. The ability to efficiently operate an inductive thruster at lower energy and power levels may provide inductive thrusters near term applicability and mission pull. The Faraday Accelerator with Radio-frequency Assisted Discharge concept demonstrated potential for a high-efficiency, low-energy pulsed inductive thruster. The added benefits of energy recapture and/or pulse compression are shown to enhance the performance of the pulsed inductive propulsion system, yielding a system that con compete with and potentially outperform current state-of-the-art electric propulsion technologies. These enhancements lead to mission-level benefits associated with the use of a pulsed inductive thruster. Analyses of low-power near to mid-term missions and higher power far-term missions are undertaken to compare the performance of pulsed inductive thrusters with that delivered by state-of-the-art and development-level electric propulsion systems.
Author
PULSED INDUCTIVE THRUSTERS; ACCELERATORS; RADIO FREQUENCY DISCHARGE; PROPULSION SYSTEM PERFORMANCE; SYSTEMS ENGINEERING; TECHNOLOGY ASSESSMENT; SPACECRAFT PROPULSION; POWER
20090001286 NASA Marshall Space Flight Center, Huntsville, AL, United States
The First Development of Human Factors Engineering Requirements for Application to Ground Task Design for a NASA Flight Program
Dischinger, H. Charles, Jr.; Stambolian, Damon B.; Miller, Darcy H.; June 29, 2008; In English; 38th International Conference on Environmental Systems, 29 Jun. - 2 Jul. 2008, San Francisco, CA, United States
Report No.(s): 08ICES-0279; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001286
The National Aeronautics and Space Administration has long applied standards-derived human engineering requirements to the development of hardware and software for use by astronauts while in flight. The most important source of these requirements has been NASA-STD-3000. While there have been several ground systems human engineering requirements documents, none has been applicable to the flight system as handled at NASA's launch facility at Kennedy Space Center. At the time of the development of previous human launch systems, there were other considerations that were deemed more important than developing worksites for ground crews; e.g., hardware development schedule and vehicle performance. However, experience with these systems has shown that failure to design for ground tasks has resulted in launch schedule delays, ground operations that are more costly than they might be, and threats to flight safety. As the Agency begins the development of new systems to return humans to the moon, the new Constellation Program is addressing this issue with a new set of human engineering requirements. Among these requirements is a subset that will apply to the design of the flight components and that is intended to assure ground crew success in vehicle assembly and maintenance tasks. These requirements address worksite design for usability and for ground crew safety.
Author
HUMAN FACTORS ENGINEERING; GROUND OPERATIONAL SUPPORT SYSTEM; NASA PROGRAMS
20090001288 Princeton Univ., Princeton, NJ, United States
Current Sheet Formation in a Conical Theta Pinch Faraday Accelerator with Radio-frequency Assisted Discharge
Polzin, Kurt A.; Hallock, Ashley K.; Choueiri, Edgar Y.; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20 - 23 Jul. 2008, Connecticut, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Data from an inductive conical theta pinch accelerator are presented to gain insight into the process of inductive current sheet formation in the presence of a preionized background gas produced by a steady-state RF-discharge. The presence of a preionized plasma has been previously shown to allow for current sheet formation at lower discharge voltages and energies than those found in other pulsed inductive accelerator concepts, leading to greater accelerator efficiencies at lower power levels. Time-resolved magnetic probe measurements are obtained for different background pressures and pulse energies to characterize the effects of these parameters on current sheet formation. Indices are defined that describe time-resolved current sheet characteristics, such as the total current owing in the current sheet, the time-integrated total current ('strength'), and current sheet velocity. It is found that for a given electric field strength, maximums in total current, strength, and velocity occur for one particular background pressure. At other pressures, these current sheet indices are considerably smaller. The trends observed in these indices are explained in terms of the principles behind Townsend breakdown that lead to a dependence on the ratio of the electric field to the background pressure. Time-integrated photographic data are also obtained at the same experimental conditions, and qualitatively they compare quite favorably with the time-resolved magnetic field data.
Author
ELECTRIC FIELDS; THETA PINCH; ACCELERATORS; CURRENT SHEETS; INDUCTANCE; RADIO FREQUENCY DISCHARGE; FARADAY EFFECT
20090001289 NASA Marshall Space Flight Center, Huntsville, AL, United States
Probability of Detection Study on Impact Damage to Honeycomb Composite Structure using Thermographic Inspection
Hodge, Andrew J.; Walker, James L., II; September 08, 2008; In English; SAMPE 2008 Fall Technical Conference, 8-11 Sep. 2008, Memphis, TN, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001289
A probability of detection study was performed for the detection of impact damage using flash heating infrared thermography on a full scale honeycomb composite structure. The honeycomb structure was an intertank structure from a previous NASA technology demonstration program. The intertank was fabricated from IM7/8552 carbon fiber/epoxy facesheets and aluminum honeycomb core. The intertank was impacted in multiple locations with a range of impact energies utilizing a spherical indenter. In a single blind study, the intertank was inspected with thermography before and after impact damage was incurred. Following thermographic inspection several impact sites were sectioned from the intertank and cross-sectioned for microscopic comparisons of NDE detection and actual damage incurred. The study concluded that thermographic inspection was a good method of detecting delamination damage incurred by impact. The 90/95 confidence level on the probability of detection was close to the impact energy that delaminations were first observed through cross-sectional analysis.
Author
DETECTION; IMPACT DAMAGE; HONEYCOMB STRUCTURES; COMPOSITE STRUCTURES; THERMOGRAPHY
20090001292 NASA Langley Research Center, Hampton, VA, United States
Optimizing Societal Benefit using a Systems Engineering Approach for Implementation of the GEOSS Space Segment
Killough, Brian D., Jr.; Sandford, Stephen P.; Cecil, L DeWayne; Stover, Shelley; Keith, Kim; November 17, 2008; In English; SPIE Asia Pacific Remote Sensing 2008, 17-21 Nov. 2008, Noumea, New Caledonia; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 144598.01.02.03
Report No.(s): 7151-1; Copyright; Avail.: CASI: A02, Hardcopy
The Group on Earth Observations (GEO) is driving a paradigm shift in the Earth Observation community, refocusing Earth observing systems on GEO Societal Benefit Areas (SBA). Over the short history of space-based Earth observing systems most decisions have been made based on improving our scientific understanding of the Earth with the implicit assumption that this would serve society well in the long run. The space agencies responsible for developing the satellites used for global Earth observations are typically science driven. The innovation of GEO is the call for investments by space agencies to be driven by global societal needs. This paper presents the preliminary findings of an analysis focused on the observational requirements of the GEO Energy SBA. The analysis was performed by the Committee on Earth Observation Satellites (CEOS) Systems Engineering Office (SEO) which is responsible for facilitating the development of implementation plans that have the maximum potential for success while optimizing the benefit to society. The analysis utilizes a new taxonomy for organizing requirements, assesses the current gaps in spacebased measurements and missions, assesses the impact of the current and planned space-based missions, and presents a set of recommendations.
Author
SYSTEMS ENGINEERING; GEOPHYSICS; CLIMATOLOGY; SATELLITE IMAGERY; EARTH OBSERVATIONS (FROM SPACE)
Additions to the NASA Aeronautics and Space Database as of 01/21/2009
20090001306 NASA Goddard Space Flight Center, Greenbelt, MD, United States
STRS Compliant FPGA Waveform Development
Nappier, Jennifer; Downey, Joseph; Mortensen, Dale; October 2008; In English; SDR Forum Technical Conference, 26 - 30 Oct. 2008, Washington, D.C., United States; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-215297; E-16566; Copyright; Avail.: CASI: A03, Hardcopy
The Space Telecommunications Radio System (STRS) Architecture Standard describes a standard for NASA space software defined radios (SDRs). It provides a common framework that can be used to develop and operate a space SDR in a reconfigurable and reprogrammable manner. One goal of the STRS Architecture is to promote waveform reuse among multiple software defined radios. Many space domain waveforms are designed to run in the special signal processing (SSP) hardware. However, the STRS Architecture is currently incomplete in defining a standard for designing waveforms in the SSP hardware. Therefore, the STRS Architecture needs to be extended to encompass waveform development in the SSP hardware. The extension of STRS to the SSP hardware will promote easier waveform reconfiguration and reuse. A transmit waveform for space applications was developed to determine ways to extend the STRS Architecture to a field programmable gate array (FPGA). These extensions include a standard hardware abstraction layer for FPGAs and a standard interface between waveform functions running inside a FPGA. A FPGA-based transmit waveform implementation of the proposed standard interfaces on a laboratory breadboard SDR will be discussed.
Author
WAVEFORMS; TELECOMMUNICATION; SPACE COMMUNICATION; RADIO EQUIPMENT; SIGNAL PROCESSING; FIELD-PROGRAMMABLE GATE ARRAYS
20090001307 NASA Glenn Research Center, Cleveland, OH, United States
An Assessment of Current Fan Noise Prediction Capability
Envia, Edmane; Woodward, Richard P.; Elliott, David M.; Fite, E. Brian; Hughes, Christopher E.; Podboy, Gary G.; Sutliff, Daniel L.; October 2008; In English; 14th Aeroacoustics Conference, 5 - 7 May 2008, Vancouver, Canada; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-215415; E-16579; Copyright; Avail.: CASI: A04, Hardcopy
In this paper, the results of an extensive assessment exercise carried out to establish the current state of the art for predicting fan noise at NASA are presented. Representative codes in the empirical, analytical, and computational categories were exercised and assessed against a set of benchmark acoustic data obtained from wind tunnel tests of three model scale fans. The chosen codes were ANOPP, representing an empirical capability, RSI, representing an analytical capability, and LINFLUX, representing a computational aeroacoustics capability. The selected benchmark fans cover a wide range of fan pressure ratios and fan tip speeds, and are representative of modern turbofan engine designs. The assessment results indicate that the ANOPP code can predict fan noise spectrum to within 4 dB of the measurement uncertainty band on a third-octave basis for the low and moderate tip speed fans except at extreme aft emission angles. The RSI code can predict fan broadband noise spectrum to within 1.5 dB of experimental uncertainty band provided the rotor-only contribution is taken into account. The LINFLUX code can predict interaction tone power levels to within experimental uncertainties at low and moderate fan tip speeds, but could deviate by as much as 6.5 dB outside the experimental uncertainty band at the highest tip speeds in some case.
Author
ACOUSTIC PROPERTIES; AERODYNAMIC NOISE; NOISE PREDICTION; TURBOFAN ENGINES; REUSABLE HEAT SHIELDING; FAN BLADES
20090001308 NASA Glenn Research Center, Cleveland, OH, United States
LOX/Methane Main Engine Igniter Tests and Modeling
Breisacher, Kevin J.; Ajmani, Kumund; November 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC05BAZZB; NNC08JF17T
Report No.(s): NASA/TM-2008-215421; AIAA Paper-2008-4757; E-16585; Copyright; Avail.: CASI: A03, Hardcopy
The LOX/methane propellant combination is being considered for the Lunar Surface Access Module ascent main engine propulsion system. The proposed switch from the hypergolic propellants used in the Apollo lunar ascent engine to LOX/methane propellants requires the development of igniters capable of highly reliable performance in a lunar surface environment. An ignition test program was conducted that used an in-house designed LOX/methane spark torch igniter. The testing occurred in Cell 21 of the Research Combustion Laboratory to utilize its altitude capability to simulate a space vacuum environment. Approximately 750 ignition test were performed to evaluate the effects of methane purity, igniter body temperature, spark energy level and frequency, mixture ratio, flowrate, and igniter geometry on the ability to obtain successful ignitions. Ignitions were obtained down to an igniter body temperature of approximately 260 R with a 10 torr back-pressure. The data obtained is also being used to anchor a CFD based igniter model.
Author
LIQUID OXYGEN; METHANE; PROPELLANTS; LUNAR SURFACE; COMPUTATIONAL FLUID DYNAMICS; HYPERGOLIC ROCKET PROPELLANTS; IGNITION; ENGINE TESTS
20090001309 NASA Glenn Research Center, Cleveland, OH, United States
The Effect of Spray Initial Conditions on Heat Release and Emissions in LDI CFD Calculations
Iannetti, Anthony C.; Liu, Nan-Suey; Davoudzadeh, Farhad; October 2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-215422; E-16591; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001309
The mass and velocity distribution of liquid spray has a primary effect on the combustion heat release process. This heat release process then affects emissions like nitrogen oxides (NOx) and carbon monoxide (CO). Computational Fluid Dynamics gives the engineer insight into these processes, but various setup options exist (number of droplet groups, and initial droplet temperature) for spray initial conditions. This paper studies these spray initial condition options using the National Combustion Code (NCC) on a single swirler lean direct injection (LDI) flame tube. Using laminar finite rate chemistry, comparisons are made against experimental data for velocity measurements, temperature, and emissions (NOx, CO).
Author
COMPUTATIONAL FLUID DYNAMICS; MASS DISTRIBUTION; HEAT OF COMBUSTION; CARBON MONOXIDE; VELOCITY DISTRIBUTION; SPRAYERS; INJECTION
20090001310 NASA Glenn Research Center, Cleveland, OH, United States
Shear Modulus for Nonisotropic, Open-Celled Foams Using a General Elongated Kelvin Foam Model
Sullivan, Roy M.; Ghosn, Louis J.; November 2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-215430; E-16613; Copyright; Avail.: CASI: A03, Hardcopy
An equation for the shear modulus for nonisotropic, open-celled foams in the plane transverse to the elongation (rise) direction is derived using an elongated Kelvin foam model with the most general geometric description. The shear modulus was found to be a function of the unit cell dimensions, the solid material properties, and the cell edge cross-section properties. The shear modulus equation reduces to the relation derived by others for isotropic foams when the unit cell is equiaxed.
Author
FOAMS; MODULUS OF ELASTICITY; ELONGATION; SHEAR PROPERTIES
20090001311 NASA Glenn Research Center, Cleveland, OH, United States; Jacobs Technology Inc., United States
Models of Lift and Drag Coefficients of Stalled and Unstalled Airfoils in Wind Turbines and Wind Tunnels
Spera, David A.; October 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC05CA95C
Report No.(s): NASA/CR-2008-215434; E-16599; Copyright; Avail.: CASI: A03, Hardcopy
Equations are developed with which to calculate lift and drag coefficients along the spans of torsionally-stiff rotating airfoils of the type used in wind turbine rotors and wind tunnel fans, at angles of attack in both the unstalled and stalled aerodynamic regimes. Explicit adjustments are made for the effects of aspect ratio (length to chord width) and airfoil thickness ratio. Calculated lift and drag parameters are compared to measured parameters for 55 airfoil data sets including 585 test points. Mean deviation was found to be -0.4 percent and standard deviation was 4.8 percent. When the proposed equations were applied to the calculation of power from a stall-controlled wind turbine tested in a NASA wind tunnel, mean deviation from 54 data points was -1.3 percent and standard deviation was 4.0 percent. Pressure-rise calculations for a large wind tunnel fan deviated by 2.7 percent (mean) and 4.4 percent (standard). The assumption that a single set of lift and drag coefficient equations can represent the stalled aerodynamic behavior of a wide variety of airfoils was found to be satisfactory.
Author
AERODYNAMIC DRAG; LIFT; AERODYNAMIC STALLING; AERODYNAMIC CHARACTERISTICS
20090001312 NASA Glenn Research Center, Cleveland, OH, United States; Sest, Inc., Middleburgh Heights, OH, United States
Advanced Stirling Convertor Heater Head Durability and Reliability Quantification
Krause, David L.; Shah, Ashwin R.; Korovaichuk, Igor; Kalluri, Sreeramesh; November 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC05BAZZB; NNC08JF17T
Report No.(s): NASA/TM-2008-215449; AIAA Paper-2008-5772; E-16652; Copyright; Avail.: CASI: A03, Hardcopy
The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for long duration Science missions, such as lunar applications, Mars rovers, and deep space missions, that require reliable design lifetimes of up to 17 years. Resistance to creep deformation of the MarM-247 heater head (HH), a structurally critical component of the ASRG Advanced Stirling Convertor (ASC), under high temperatures (up to 850 C) is a key design driver for durability. Inherent uncertainties in the creep behavior of the thin-walled HH and the variations in the wall thickness, control temperature, and working gas pressure need to be accounted for in the life and reliability prediction. Due to the availability of very limited test data, assuring life and reliability of the HH is a challenging task. The NASA Glenn Research Center (GRC) has adopted an integrated approach combining available uniaxial MarM-247 material behavior testing, HH benchmark testing and advanced analysis in order to demonstrate the integrity, life and reliability of the HH under expected mission conditions. The proposed paper describes analytical aspects of the deterministic and probabilistic approaches and results. The deterministic approach involves development of the creep constitutive model for the MarM-247 (akin to the Oak Ridge National Laboratory master curve model used previously for Inconel 718 (Special Metals Corporation)) and nonlinear finite element analysis to predict the mean life. The probabilistic approach includes evaluation of the effect of design variable uncertainties in material creep behavior, geometry and operating conditions on life and reliability for the expected life. The sensitivity of the uncertainties in the design variables on the HH reliability is also quantified, and guidelines to improve reliability are discussed.
Author
STIRLING CYCLE; CREEP PROPERTIES; DESIGN ANALYSIS; FINITE ELEMENT METHOD; HEAT RESISTANT ALLOYS; HIGH TEMPERATURE; RELIABILITY ANALYSIS; DEFORMATION; GAS PRESSURE
20090001313 NASA Glenn Research Center, Cleveland, OH, United States
Preliminary Test Results of a Non-Contacting Finger Seal on a Herringbone-Grooved Rotor
Proctor, Margaret P.; Degado, Irebert R.; November 2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-215475; AIAA Paper-2008-4506; E-16560-1; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001313
Low leakage, non-contacting finger seals have potential to reduce gas turbine engine specific fuel consumption by 2 to 3 percent and to reduce direct operating costs by increasing the time between engine overhauls. A non-contacting finger seal with concentric lift-pads operating adjacent to a test rotor with herringbone grooves was statically tested at 300, 533, and 700 K inlet air temperatures at pressure differentials up to 576 kPa. Leakage flow factors were approximately 70 percent less than state-of-the-art labyrinth seals. Leakage rates are compared to first order predictions. Initial spin tests at 5000 rpm, 300 K inlet air temperature and pressure differentials to 241 kPa produced no measurable wear.
Author
LEAKAGE; LABYRINTH SEALS; BRUSH SEALS; GAS PRESSURE; INLET TEMPERATURE; GAS TURBINE ENGINES; FUEL CONSUMPTION
20090001316 NASA Johnson Space Center, Houston, TX, United States
Chemistry of Diogenites and Evolution of their Parent Asteroid
Mittlefehldt, D.W.; Beck, A.W.; McSween, H.Y.; Lee, C-T A.; [2009]; In English; 40th Lunar and Planetary Science Conference, 23 - 27 Mar. 2009, Texas, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Diogenites are orthopyroxenite meteorites [1]. Most are breccias, but remnant textures indicate they were originally coarse-grained rocks, with grain sizes of order of cm. Their petrography, and major and trace element chemistry support an origin as crustal cumulates from a differentiated asteroid. Diogenites are genetically related to the basaltic and cumulate-gabbro eucrites, and the polymict breccias known as howardites, collectively, the HED suite. Spectroscopic observations, orbit data and dynamical arguments strongly support the hypothesis that asteroid 4 Vesta is the parent object for HED meteorites [2]. Here we discuss our new trace element data for a suite of diogenites and integrate these into the body of literature data. We use the combined data set to discuss the petrologic evolution of diogenites and 4 Vesta.
Derived from text
ACHONDRITES; ASTEROIDS; METEORITIC COMPOSITION; PETROGRAPHY; TRACE ELEMENTS; VESTA ASTEROID; METEORITES; BRECCIA
20090001317 NASA Johnson Space Center, Houston, TX, United States
Photometric Studies of Orbital Debris at GEO
Seitzer, Patrick; Abercromby, Kira J.; Rodriguez-Cowardin, Heather M.; Barker, Ed; Foreman, Gary; Horstman, Matt; January 2009; In English; 5th European Conference on Space Debris, 30 Mar. - 2 Apr. 2009, Darmstadt, Germany
Copyright; Avail.: CASI: A01, Hardcopy
We report on optical observations of debris at geosynchronous Earth orbit (GEO) using two telescopes simultaneously at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. The University of Michigan s 0.6/0.9-m Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope) was used in survey mode to find objects that potentially could be at GEO. Because GEO objects only appear in this telescope s field of view for an average of 5 minutes, a full six-parameter orbit can not be determined. Interrupting the survey for follow-up observations leads to incompleteness in the survey results. Instead, as objects are detected with MODEST, initial predictions assuming a circular orbit are done for where the object will be for the next hour, and the objects are reacquired as quickly as possible on the CTIO 0.9-m telescope. This second telescope follows-up during the first night and, if possible, over several more nights to obtain the maximum time arc possible, and the best six parameter orbit. Our goal is to obtain an initial orbit and calibrated colors for all detected objects fainter than R = 15th in order to estimate the orbital distribution of objects selected on the basis of two observational criteria: magnitude and angular rate. One objective is to estimate what fraction of objects selected on the basis of angular rate are not at GEO. A second objective is to obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials.
Author
GEOSYNCHRONOUS ORBITS; SCHMIDT TELESCOPES; VISUAL OBSERVATION; FIELD OF VIEW; SPACE DEBRIS; CIRCULAR ORBITS; ASTRONOMY
20090001318 NASA Johnson Space Center, Houston, TX, United States
Human Systems Integration (HSI) Case Studies from the NASA Constellation Program
Baggerman, Susan; Berdich, Debbie; Whitmore, Mihriban; January 2009; In English; Human Systems Integration Symposium @ISIS) 2009, 17 - 19 Mar. 2009, Maryland, United States
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001318
The National Aeronautics and Space Administration (NASA) Constellation Program is responsible for planning and implementing those programs necessary to send human explorers back to the moon, onward to Mars and other destinations in the solar system, and to support missions to the International Space Station. The Constellation Program has the technical management responsibility for all Constellation Projects, including both human rated and non-human rated vehicles such as the Crew Exploration Vehicle, EVA Systems, the Lunar Lander, Lunar Surface Systems, and the Ares I and Ares V rockets. With NASA s new Vision for Space Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, inclusion in trade offs and analyses, and an iterative "prototype/test/ redesign" process. Personnel at the NASA Johnson Space Center are involved in the Constellation Program at both the Program and Project levels as human system integrators. They ensure that the human is considered as a system, equal to hardware and software vehicle systems. Systems to deliver and support extended human habitation on the moon are extremely complex and unique, presenting new opportunities to employ Human Systems Integration, or HSI practices in the Constellation Program. The purpose of the paper is to show examples of where human systems integration work is successfully employed in the Constellation Program and related Projects, such as in the areas of habitation and early requirements and design concepts.
Author
CONSTELLATION PROGRAM; NASA PROGRAMS; SYSTEMS INTEGRATION; EXTRAVEHICULAR ACTIVITY; SPACE PROGRAMS; LUNAR SURFACE; ARES 5 CARGO LAUNCH VEHICLE
20090001334 United Space Alliance, Houston, TX, United States
Space Shuttle Usage of z/OS
Green, Jan; March 2009; In English; SHARE (Session 2819), 1-6 Mar. 2009, Austin, TX, United States; Original contains color illustrations
Contract(s)/Grant(s): NAS9-20000; NNJ06VA01C
Copyright; Avail.: CASI: A04, Hardcopy
This viewgraph presentation gives a detailed description of the avionics associated with the Space Shuttle's data processing system and its usage of z/OS. The contents include: 1) Mission, Products, and Customers; 2) Facility Overview; 3) Shuttle Data Processing System; 4) Languages and Compilers; 5) Application Tools; 6) Shuttle Flight Software Simulator; 7) Software Development and Build Tools; and 8) Fun Facts and Acronyms.
CASI
AVIONICS; DATA PROCESSING EQUIPMENT; SPACE SHUTTLES; AIRBORNE/SPACEBORNE COMPUTERS; SOFTWARE ENGINEERING; SPACE SHUTTLE BOOSTERS; OPERATING SYSTEMS (COMPUTERS); COMPUTERIZED SIMULATION
20090001338 NASA Glenn Research Center, Cleveland, OH, United States
Exploring Venus
Landis, Geoffrey A.; January 17, 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 361426.07.03
No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001338
With a temperature higher than the inside of your oven and atmospheric pressure equal to that a kilometer under the ocean, the surface of Venus is one of the most hostile environments in the solar system, and Venus exploration presents a challenge to technology. This lecture presents mission trade-offs and discusses a proposed mission concept for rover and aircraft based exploration of the surface and atmosphere of Venus. Several approaches to the technology, electronics, mechanical parts, and power systems, are discussed.
Author
VENUS ATMOSPHERE; VENUS (PLANET); SOLAR SYSTEM; VENUS SURFACE; SPACE EXPLORATION
20090001339 NASA Glenn Research Center, Cleveland, OH, United States
AMBR [Advanced Material Bipropellant Rocket] Engine for Science Missions
Liou, Larry C.; July 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 345620.01.03.01
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001339
This viewgraph presentation reviews the Advanced Material Bipropellant Rocket (AMBR) in space propulsion technology for Space Missions.
CASI
AEROSPACE ENGINEERING; LIQUID ROCKET PROPELLANTS; SPACE MISSIONS; TECHNOLOGY UTILIZATION
20090001340 NASA Glenn Research Center, Cleveland, OH, United States
Effect of Excess Lead and Bismuth Content on the Electrical Properties of High-Temperature Bismuth Scandium Lead Titanate Ceramics
Sehirlioglu, Alp; Sayir, Ali; February 24, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC07TA77T
Copyright; Avail.: CASI: A03, Hardcopy
Aeronautic and aerospace applications require piezoelectric materials that can operate at high temperatures. The air-breathing aeronautic engines can use piezoelectric actuators for active combustion control for fuel modulation to mitigate thermo-acoustic instabilities and/or gas flow control to improve efficiency. The principal challenge for the insertion of piezoelectric materials is their limitation for upper use temperature and this limitation is due low Curie temperature and increasing conductivity. We investigated processing, microstructure and property relationship of (1-x)BiScO3-(x)PbTiO3 (BS-PT) composition as a promising high temperature piezoelectric. The effect of excess Pb and Bi and their partitioning in grain boundaries were studied using impedance spectroscopy, ferroelectric, and piezoelectric measurement techniques. Excess Pb addition increased the grain boundary conduction and the grain boundary area (average grain size was 24.8 m, and 1.3 m for compositions with 0at.% and 5at.% excess Pb, respectively) resulting in ceramics with higher AC conductivity (tan d= 0.9 and 1.7 for 0at.% and 5at.% excess Pb at 350 C and at 10kHz) that were not resistive enough to pole. Excess Bi addition increased the resistivity (rho= 4.1x10(exp 10) Omega cm and 19.6 x10(exp 10) Omega.cm for compositions with 0at.% and 5at.% excess Bi, respectively), improved poling, and increased the piezoelectric coefficient from 137 to 197 pC/N for 5at.% excess Bi addition. In addition, loss tangent decreased more than one order of magnitude at elevated temperatures (greater than 300 C). For all compositions the activation energy of the conducting species was similar (approximately equal to 0.35-0.40 eV) and indicated electronic conduction.
Author
BISMUTH; CERAMICS; ELECTRICAL PROPERTIES; HIGH TEMPERATURE; LEAD TITANATES; MICROSTRUCTURE; PIEZOELECTRICITY; SCANDIUM
20090001341 NASA Glenn Research Center, Cleveland, OH, United States
Collaboration with Williams International to Demonstrate the Characteristics of a Foam-Metal-Liner Installed Over-the-Rotor of a Turbofan Engine
Sutliff, Daniel; Elliott, Dave; Jones, Mike; Hartley, Tom; September 23, 2008; In English; Acoustics Technical Working Group Meeting, 23-24 Sep. 2008, FROM, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 685676.01.03.08.05
Copyright; Avail.: CASI: A03, Hardcopy
A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for foam-metal liner installed in close proximity to the fan. Two foam metal liner designs were tested and compared to the hardwall. Traditional Single-Degree-of-Freedom liner designs were also evaluated to provide a comparison. Normalized information on farfield acoustics is presented in this paper. The results show that up to 5 dB PWL overall attenuation was achieved in the forward quadrant. In general, the foam-metal liners performed better when the fan tip speed was below sonic.
Derived from text
LININGS; ROTORS; TURBOFAN ENGINES; TEST FACILITIES; AEROACOUSTICS; METAL FOAMS
20090001343 NASA Glenn Research Center, Cleveland, OH, United States
Proposed Facility Modifications to Support Propulsion Systems Testing Under Simulated Space Conditions at Plum Brook Station's Spacecraft Propulsion Research Facility (B-2)
Edwards, Daryl A.; September 10, 2008; In English; Thermal and Fluid Analysis Workshop (TFAWS 2007), 10-14 Sep. 2007, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 750271.09.04.03
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001343
Preparing NASA's Plum Brook Station's Spacecraft Propulsion Research Facility (B-2) to support NASA's new generation of launch vehicles has raised many challenges for B-2's support staff. The facility provides a unique capability to test chemical propulsion systems/vehicles while simulating space thermal and vacuum environments. Designed and constructed in the early 1960s to support upper stage cryogenic engine/vehicle system development, the Plum Brook Station B-2 facility will require modifications to support the larger, more powerful, and more advanced engine systems for the next generation of vehicles leaving earth's orbit. Engine design improvements over the years have included large area expansion ratio nozzles, greater combustion chamber pressures, and advanced materials. Consequently, it has become necessary to determine what facility changes are required and how the facility can be adapted to support varying customers and their specific test needs. Exhaust system performance, including understanding the present facility capabilities, is the primary focus of this work. A variety of approaches and analytical tools are being employed to gain this understanding. This presentation discusses some of the challenges in applying these tools to this project and expected facility configuration to support the varying customer needs.
Author
ENGINE DESIGN; RESEARCH FACILITIES; SIMULATION; SPACECRAFT PROPULSION
20090001348 NASA Stennis Space Center, Stennis Space Center, MS, United States
Computational Analyses of Pressurization in Cryogenic Tanks
Ahuja, Vineet; Hosangadi, Ashvin; Mattick, Stephen; Lee, Chun P.; Field, Robert E.; Ryan, Harry; July 21, 2008; In English; 44rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color illustrations
Contract(s)/Grant(s): NNSO6AA12C
Report No.(s): SSTI-8080-0022; Copyright; Avail.: CASI: A03, Hardcopy
A) Advanced Gas/Liquid Framework with Real Fluids Property Routines: I. A multi-fluid formulation in the preconditioned CRUNCH CFD(Registered TradeMark) code developed where a mixture of liquid and gases can be specified: a) Various options for Equation of state specification available (from simplified ideal fluid mixtures, to real fluid EOS such as SRK or BWR models). b) Vaporization of liquids driven by pressure value relative to vapor pressure and combustion of vapors allowed. c) Extensive validation has been undertaken. II. Currently working on developing primary break-up models and surface tension effects for more rigorous phase-change modeling and interfacial dynamics B) Framework Applied to Run-time Tanks at Ground Test Facilities C) Framework Used For J-2 Upper Stage Tank Modeling: 1) NASA MSFC tank pressurization: a) Hydrogen and oxygen tank pre-press, repress and draining being modeled at NASA MSFC. 2) NASA AMES tank safety effort a) liquid hydrogen and oxygen are separated by a baffle in the J-2 tank. We are modeling pressure rise and possible combustion if a hole develops in the baffle and liquid hydrogen leaks into the oxygen tank. Tank pressure rise rates simulated and risk of combustion evaluated.
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LIQUID HYDROGEN; GAS MIXTURES; INTERFACIAL TENSION; J-2 ENGINE; VAPOR PRESSURE; COMBUSTION; EQUATIONS OF STATE; ANALYSIS (MATHEMATICS)
Additions to the NASA Aeronautics and Space Database as of 01/22/2009
20090001826 NASA Goddard Space Flight Center, Greenbelt, MD, United States
NASA Electronic Parts and Packaging (NEPP) Program - Radiation Activities
LaBel, Kenneth A.; Sampson, Michael J.; October 22, 2008; In English; Radiation Hardened Electronics Technology (RHET), 22-23 Oct. 2008, Colorado Springs, CO, FROM; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001826
The NEPP mission is to provide guidance to NASA for the selection and application of microelectronics technologies, to improve understanding of the risks related to the use of these technologies in the space environment and to ensure that appropriate research is performed to meet NASA mission assurance needs.
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AEROSPACE ENVIRONMENTS; MICROELECTRONICS; ELECTRONIC PACKAGING
20090001833 NASA Marshall Space Flight Center, Huntsville, AL, United States
Electron Calorimeter Experiment
Adams, James H.; July 13, 2008; In English; 37th COSPAR Scientific Assembly, 13 - 20 Jul. 2008, Montreal, Canada; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001833
Boron loaded scintillators are suitable for measuring secondary neutrons produced by high-energy particles: protons & electrons Neutron flux can be used to discriminate hadron and electro-magnetic particles Combined effectiveness of all e/p discriminators techniques employedTBD Only moderate improvement in detection efficiency for B-10 concentrations >few% in thick moderators Bottom scintillator might serve as cascade penetration counter (TBC)
Author
BORON 10; CALORIMETERS; PROTONS; HADRONS; FLUX (RATE); ELECTRONS
20090001843 NASA Marshall Space Flight Center, Huntsville, AL, United States
Operational Characteristics and Plasma Measurements in a Low-Energy FARAD Thruster
Polzin, K. A.; Best, S.; Rose, M. F.; Miller, R.; Owens, T.; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford, CT, United States; Original contains black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Pulsed inductive plasma accelerators are spacecraft propulsion devices in which energy is stored in a capacitor and then discharged through an inductive coil. The device is electrodeless, inducing a plasma current sheet in propellant located near the face of the coil. The propellant is accelerated and expelled at a high exhaust velocity (order of 10 km/s) through the interaction of the plasma current with an induced magnetic field. The Faraday Accelerator with RF-Assisted Discharge (FARAD) thruster is a type of pulsed inductive plasma accelerator in which the plasma is preionized by a mechanism separate from that used to form the current sheet and accelerate the gas. Employing a separate preionization mechanism in this manner allows for the formation of an inductive current sheet at much lower discharge energies and voltages than those found in previous pulsed inductive accelerators like the Pulsed Inductive Thruster (PIT). In this paper, we present measurements aimed at quantifying the thruster's overall operational characteristics and providing additional insight into the nature of operation. Measurements of the terminal current and voltage characteristics during the pulse help quantify the output of the pulsed power train driving the acceleration coil. A fast ionization gauge is used to measure the evolution of the neutral gas distribution in the accelerator prior to a pulse. The preionization process is diagnosed by monitoring light emission from the gas using a photodiode, and a time-resolved global view of the evolving, accelerating current sheet is obtained using a fast-framing camera. Local plasma and field measurements are obtained using an array of intrusive probes. The local induced magnetic field and azimuthal current density are measured using B-dot probes and mini-Rogowski coils, respectively. Direct probing of the number density and electron temperature is performed using a triple probe.
Author
PLASMA ACCELERATORS; SPACECRAFT PROPULSION; ELECTROMAGNETIC ACCELERATION; PLASMA PROPULSION; MAGNETOPLASMADYNAMIC THRUSTERS
20090001869 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Laser Sounder Approach for Global Measurement of Tropospheric CO2 Mixing Ratio from Space
Abshire, James B.; Riris, Haris; Allan, Graham; Kawa, S. Randy; Mayo, Jian-Ping; Wilson, Emily; Stephen, Mark; Chen, Jeffrey; Sun, Xiaoli; Weaver, Clark; December 16, 2008; In English; American Geophysical Union Meeting, 16-19 Dec. 2008, San Francisco, CA, United States; Original contains black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
We report progress in assessing the feasibility of a new satellite-based laser-sounding instrument to measure CO2 and other trace gas abundances in the lower troposphere from space.
Author
CARBON DIOXIDE; MIXING RATIOS; TROPOSPHERE; OPTICAL RADAR; METEOROLOGY; TRACE CONTAMINANTS
20090001871 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Parts Selection for Space Systems - An Overview and Radiation Perspective
LaBel, Kenneth A.; November 30, 2008; In English; 4th International School on the Effects of Radiation on Embedded Systems for Space Applications (SERESSA), 30 Nov. - 5 Dec. 2008, West Palm Beach, FL, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001871
This viewgraph presentation describes the selection of electronic parts for aerospace systems from a space radiation perspective. The topics include: 1) The Trade Space Involved with Part Selection; 2) Understanding Risk; 3) Technical/Design Aspects; 4) Programmatic Overview; 5) Radiation Perspective; 6) Reliability Considerations; 7) An Example Ad hoc Battle; and 8) Sources of Radiation Data.
CASI
AEROSPACE SYSTEMS; EXTRATERRESTRIAL RADIATION; SPACECRAFT COMPONENTS; MECHANICAL DEVICES; RELIABILITY ENGINEERING; ASTRIONICS
Additions to the NASA Aeronautics and Space Database as of 01/23/2009
20090001886 NASA Marshall Space Flight Center, Huntsville, AL, United States
In-situ Observations of the Ionospheric F2-Region from the International Space Station
Coffey, Victoria N.; Wright, Kenneth H.; Minow, Joseph I.; Chandler, Michael O.; Parker, Linda N.; July 13, 2008; In English; 37th COSPAR Scientific Assembly, 13-20 Jul. 2008, Montreal, Canada; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
The International Space Station orbit provides an ideal platform for in-situ studies of space weather effects on the mid and low latitude F-2 region ionosphere. The Floating Potential Measurement Unit (FPMU) operating on the ISS since Aug 2006, is a suite of plasma instruments: a Floating Potential Probe (FPP), a Plasma Impedance Probe (PIP), a Wide-sweep Langmuir Probe (WLP), and a Narrow-sweep Langmuir Probe (NLP). This instrument package provides a new opportunity for collaborative multi-instrument studies of the F-region ionosphere during both quiet and disturbed periods. This presentation first describes the operational parameters for each of the FPMU probes and shows examples of an intra-instrument validation. We then show comparisons with the plasma density and temperature measurements derived from the TIMED GUVI ultraviolet imager, the Millstone Hill ground based incoherent scatter radar, and DIAS digisondes, Finally we show one of several observations of night-time equatorial density holes demonstrating the capabilities of the probes for monitoring mid and low latitude plasma processes.
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INTERNATIONAL SPACE STATION; SPACE WEATHER; IN SITU MEASUREMENT; INSTRUMENT PACKAGES; F 2 REGION; IONOSONDES
20090001888 Jacobs Technologies Engineering Science Contract Group, Houston, TX, United States
Scaling of Performance in Liquid Propellant Rocket Engine Combustion Devices
Hulka, James R.; July 21, 2008; In English; AIAA/ASME/SAE Joint Propulsion Conference, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNM05AB50C
Copyright; Avail.: CASI: A03, Hardcopy
This paper discusses scaling of combustion and combustion performance in liquid propellant rocket engine combustion devices. In development of new combustors, comparisons are often made between predicted performance in a new combustor and measured performance in another combustor with different geometric and thermodynamic characteristics. Without careful interpretation of some key features, the comparison can be misinterpreted and erroneous information used in the design of the new device. This paper provides a review of this performance comparison, including a brief review of the initial liquid rocket scaling research conducted during the 1950s and 1960s, a review of the typical performance losses encountered and how they scale, a description of the typical scaling procedures used in development programs today, and finally a review of several historical development programs to see what insight they can bring to the questions at hand.
Author
LIQUID PROPELLANT ROCKET ENGINES; COMBUSTION CHAMBERS; COMBUSTION; SCALING; PERFORMANCE TESTS; COMBUSTION EFFICIENCY; PROPULSION SYSTEM PERFORMANCE; AEROSPACE ENGINEERING
20090001890 NASA Marshall Space Flight Center, Huntsville, AL, United States
Effect of Chamber Backpressure on Swirl Injector Fluid Mechanics
Kenny, R. Jeremy; Hulka, James R.; Moser, Marlow D.; Rhys, Noah O.; July 21, 2008; In English; 44th AIAA Joint Propulsion Conference, 21-24 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
A common propellant combination used for high thrust generation is GH2/LOX. Historical GH2/LOX injection elements have been of the shear-coaxial type. Element type has a large heritage of research work to aid in element design. The swirl-coaxial element, despite its many performance benefits, has a relatively small amount of historical, LRE-oriented work to draw from. Design features of interest are grounded in the fluid mechanics of the liquid swirl process itself, are based on data from low-pressure, low mass flow rate experiments. There is a need to investigate how high ambient pressures and mass flow rates influence internal and external swirl features. The objective of this research is to determine influence of varying liquid mass flow rate and ambient chamber pressure on the intact-length fluid mechanics of a liquid swirl element.
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SWIRLING; FLUID MECHANICS; LIQUID FLOW; FLOW CHAMBERS; PRESSURE EFFECTS
20090001893 NASA Marshall Space Flight Center, Huntsville, AL, United States
Ares I Crew Launch Vehicle Upper Stage Avionics and Software Overview
Nola, Charles L.; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford, CT, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001893
This viewgraph presentation gives an overall description of the avionics and software functions of the Ares I Upper Stage Crew Launch Vehicle. The contents include: 1) IUA Team - Development Approach Roadmap; 2) Ares I US Avionics and Software Development Approach; 3) NDT Responsibilities; 4) Ares I Upper Stage Avionics Locations; 5) Ares I Overall Avionics & Software Functions; 6) Block Diagram Version of Avionics Architecture; 7) Instrument Unit Avionics Preliminary Design; and 8) Upper Stage Avionics External Interfaces.
CASI
ARES 1 UPPER STAGE; SOFTWARE ENGINEERING; GENERAL OVERVIEWS; AVIONICS; NASA SPACE PROGRAMS
20090001894 Lockheed Martin Space Systems Co., New Orleans, LA, United States
Applications of Computed Tomography to Evaluate Cellular Solid Interfaces
Maisano, Josephine; Marse, Daryl J.; Schilling, Paul J.; July 21, 2008; In English; ASNT Digital Imaging XI, 21-23 Jul. 2008, Mashantucket, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS8-00016
Copyright; Avail.: CASI: A03, Hardcopy
The major morphological features - foam cells, voids, knit lines, and the bondline interface were evaluated. The features identified by micro-CT correlate well to those observed by SEM. 3D reconstructions yielded volumetric dimensions for large voids (max ~ 30 mm). Internal voids and groupings of smaller cells at the bondline are concluded to be the cause of the indications noted during the NDE prescreening process.
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SOLID SURFACES; TOMOGRAPHY; NONDESTRUCTIVE TESTS; RADIOGRAPHY; MECHANICAL ENGINEERING
20090001895 NASA Marshall Space Flight Center, Huntsville, AL, United States
HERO: A Balloon-Borne Focusing Hard X-Ray Telescope
Ramsey, Brian D.; Stahl, H. Philip; July 07, 2008; In English; ICO-21 2008 Congress "Optics for the 21st Century" (International Commission for Optics), 7-10 Jul. 2008, Sydney, Australia; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001895
This viewgraph presentation describes the HERO balloon-borne payload configuration, instrument specifications, flight operations, sensitivity analyses, and future flight plans.
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BALLOON-BORNE INSTRUMENTS; X RAY TELESCOPES; PAYLOADS; FABRICATION; SYSTEMS ENGINEERING
20090001896 NASA Marshall Space Flight Center, Huntsville, AL, United States
Development and Testing of Space Fission Technology at NASA-MSFC
Polzin, Kurt; Pearson, J. Boise; Houts, Michael; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001896
The Early Flight Fission Test Facility (EFF-TF) at NASA-Marshall Space Flight Center (MSFC) provides a capability to perform hardware-directed activities to support multiple inspace nuclear reactor concepts by using a non-nuclear test methodology. This includes fabrication and testing at both the module/component level and near prototypic reactor configurations allowing for realistic thermal-hydraulic evaluations of systems. The EFF-TF is currently performing non-nuclear testing of hardware to support a technology development effort related to an affordable fission surface power (AFSP) system that could be deployed on the Lunar surface. The AFSP system is presently based on a pumped liquid metal-cooled reactor design, which builds on US and Russian space reactor technology as well as extensive US and international terrestrial liquid metal reactor experience. An important aspect of the current hardware development effort is the information and insight that can be gained from experiments performed in a relevant environment using realistic materials. This testing can often deliver valuable data and insights with a confidence that is not otherwise available or attainable. While the project is currently focused on potential fission surface power for the lunar surface, many of the present advances, testing capabilities, and lessons learned can be applied to the future development of a low-cost in-space fission power system. The potential development of such systems would be useful in fulfilling the power requirements for certain electric propulsion systems (magnetoplasmadynamic thruster, high-power Hall and ion thrusters). In addition, inspace fission power could be applied towards meeting spacecraft and propulsion needs on missions further from the Sun, where the usefulness of solar power is diminished. The affordable nature of the fission surface power system that NASA may decide to develop in the future might make derived systems generally attractive for powering spacecraft and propulsion systems in space. This presentation will discuss work on space nuclear systems that has been performed at MSFC's EFF-TF over the past 10 years. Emphasis will be place on both ongoing work related to FSP and historical work related to in-space systems potentially useful for powering electric propulsion systems.
Author
FISSION; TECHNOLOGY UTILIZATION; TEST FACILITIES; FABRICATION; CIRCUITS
20090001897 NASA Marshall Space Flight Center, Huntsville, AL, United States
NASA's Agency-Wide Strategy for Environmental Regulatory Risk Analysis and Communication
Scroggins, Sharon; Duda, Kristen; June 24, 2008; In English; Air and Waste Management Annual Conference, 24-27 Jun. 2008, Portland, OR, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001897
This viewgraph presentation gives an overview of NASA's risk analysis communication programs associated with changing environmental policies. The topics include: 1) NASA Program Transition; 2) Principal Center for Regulatory Risk Analysis and Communication (RRAC PC); and 3) Regulatory Tracking and Communication Process.
CASI
NASA PROGRAMS; RISK MANAGEMENT; REGULATIONS; COMMUNICATION
20090001898 Lockheed Martin Space Systems Co., New Orleans, LA, United States
Application of Terahertz Imaging and Backscatter Radiography to Space Shuttle Foam Inspection
Ussery, Warren; July 21, 2008; In English; American Society for Nondestructive Testing (ASNT), 21-23 Jul. 2008, Mashantucket, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS8-00016
Copyright; Avail.: CASI: A03, Hardcopy
Two state of the art technologies have been developed for External Fuel Tank foam inspections. Results of POD tests have shown Backscatter Radiography and Terahertz imaging detect critical defects with no false positive issue. These techniques are currently in use on the External Tank program as one component in the foam quality assurance program.
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BACKSCATTERING; IMAGING TECHNIQUES; INSPECTION; SPACE SHUTTLES; RADIOGRAPHY; POLYURETHANE FOAM
20090001900 NASA Marshall Space Flight Center, Huntsville, AL, United States
Michoud Assembly Facility (MAF), 'Spray in Air' Overview
Albyn, Keith; Burns, DeWitt; August 28, 2008; In English; Informational Briefing to Prospective Vendor, 29 Aug. 2008, New Orleans, LA, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001900
A general overview of the Michoud Assembly Facility Spray in Air processing is presented. The possible areas of Spray in Air Processing at the Michoud Assembly Facility are also identified.
CASI
TEST FACILITIES; GENERAL OVERVIEWS; ARES 1 UPPER STAGE; SPRAYING; FABRICATION; EXTERNAL TANKS
20090001903 NASA Marshall Space Flight Center, Huntsville, AL, United States
Learning About Ares I from Monte Carlo Simulation
Hanson, John M.; Hall, Charlie E.; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001903
This paper addresses Monte Carlo simulation analyses that are being conducted to understand the behavior of the Ares I launch vehicle, and to assist with its design. After describing the simulation and modeling of Ares I, the paper addresses the process used to determine what simulations are necessary, and the parameters that are varied in order to understand how the Ares I vehicle will behave in flight. Outputs of these simulations furnish a significant group of design customers with data needed for the development of Ares I and of the Orion spacecraft that will ride atop Ares I. After listing the customers, examples of many of the outputs are described. Products discussed in this paper include those that support structural loads analysis, aerothermal analysis, flight control design, failure/abort analysis, determination of flight performance reserve, examination of orbit insertion accuracy, determination of the Upper Stage impact footprint, analysis of stage separation, analysis of launch probability, analysis of first stage recovery, thrust vector control and reaction control system design, liftoff drift analysis, communications analysis, umbilical release, acoustics, and design of jettison systems.
Author
AEROTHERMODYNAMICS; MONTE CARLO METHOD; ARES 1 LAUNCH VEHICLE; THRUST VECTOR CONTROL; STRUCTURAL ANALYSIS; FAILURE ANALYSIS; FLIGHT CHARACTERISTICS
20090001904 NASA Marshall Space Flight Center, Huntsville, AL, United States
Orbital Express AVGS Validation and Calibration for Automated Rendezvous
Heaton, Andrew F.; Howard, Richard T.; Pinson, Robin M.; August 17, 2008; In English; AIAA Astrodynamics Specialist Conference, 17-2 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001904
From March to July of 2007, the DARPA Orbital Express mission achieved a number of firsts in autonomous spacecraft operations. The NASA Advanced Video Guidance Sensor (AVGS) was the primary docking sensor during the first two dockings and was used in a blended mode three other automated captures. The AVGS performance exceeded its specification by approximately an order of magnitude. One reason that the AVGS functioned so well during the mission was that the validation and calibration of the sensor prior to the mission advanced the state-of-the-art for proximity sensors. Some factors in this success were improvements in ground test equipment and truth data, the capability for ILOAD corrections for optical and other effects, and the development of a bias correction procedure. Several valuable lessons learned have applications to future proximity sensors.
Author
GUIDANCE SENSORS; DOCKING; CALIBRATING; GROUND TESTS; AUTONOMY
20090001910 NASA Johnson Space Center, Houston, TX, United States
Control of the Diameter and Chiral Angle Distributions during Production of Single-wall Carbon Nanotubes
Nikolaev, Pavel; Holmes, William; Sosa, Edward; Boul, Peter; Arepalli, Sivaram; Yowell, Leonard; December 2008; In English; 2008 MRS Fall meeting, 1-5 Dec. 2008, Boston, MA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNJ05HI05C; SAAAT07021
Copyright; Avail.: CASI: A03, Hardcopy
Many applications of single wall carbon nanotubes (SWCNT), especially in microelectronics, will benefit from use of certain (n,m) nanotube types (metallic, small gap semiconductor, etc.). However, as produced SWCNT samples are polydispersed, with many (n,m) types present and typical approximate 1:2 metal/semiconductor ratio. It has been recognized that production of SWCNTs with narrow 'tube type populations' is beneficial for their use in applications, as well as for the subsequent sorting efforts. In the present work, SWCNTs were produced by a pulsed laser vaporization (PLV) technique. The nanotube type populations were studied with respect to the production temperature with two catalyst compositions: Co/Ni and Rh/Pd. The nanotube type populations were measured via photoluminescence, UV-Vis-NIR absorption and Raman spectroscopy. It was found that in the case of Co/Ni catalyst, decreased production temperature leads to smaller average diameter, exceptionally narrow diameter distribution, and strong preference toward (8,7) nanotubes. The other nanotubes present are distributed evenly in the 7-30 deg chiral angle range. In the case of Rh/Pd catalyst, a decrease in the temperature leads to a small decrease in the average diameter, with the chiral angle distribution skewed towards 30 o and a preference toward (7,6), (8,6) and (8,7) nanotubes. However, the diameter distribution remains rather broad. These results demonstrate that PLV production technique can provide at least partial control over the nanotube (n,m) populations. In addition, these results have implications for the understanding the nanotube nucleation mechanism in the laser oven.
Author
CARBON NANOTUBES; NANOFABRICATION; DIAMETERS; CHIRALITY; PULSED LASERS; VAPORIZING; NANOSTRUCTURE GROWTH
20090001918 NASA Marshall Space Flight Center, Huntsville, AL, United States
On the Period-Amplitude and Amplitude-Period Relationships
Wilson, Robert M.; Hathaway, David H.; November 2008; In English; Original contains black and white illustrations
Report No.(s): NASA/TP-2008-215580; M-1245; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001918
Examined are Period-Amplitude and Amplitude-Period relationships based on the cyclic behavior of the 12-month moving averages of monthly mean sunspot numbers for cycles 0.23, both in terms of Fisher's exact tests for 2x2 contingency tables and linear regression analyses. Concerning the Period-Amplitude relationship (same cycle), because cycle 23's maximum amplitude is known to be 120.8, the inferred regressions (90-percent prediction intervals) suggest that its period will be 131 +/- 24 months (using all cycles) or 131 +/- 18 months (ignoring cycles 2 and 4, which have the extremes of period, 108 and 164 months, respectively). Because cycle 23 has already persisted for 142 months (May 1996 through February 2008), based on the latter prediction, it should end before September 2008. Concerning the Amplitude-Period relationship (following cycle maximum amplitude versus preceding cycle period), because cycle 23's period is known to be at least 142 months, the inferred regressions (90-percent prediction intervals) suggest that cycle 24's maximum amplitude will be about less than or equal to 96.1 +/- 55.0 (using all cycle pairs) or less than or equal to 91.0 +/- 36.7 (ignoring statistical outlier cycle pairs). Hence, cycle 24's maximum amplitude is expected to be less than 151, perhaps even less than 128, unless cycle pair 23/24 proves to be a statistical outlier.
Author
SUN; SUNSPOT CYCLE; REGRESSION ANALYSIS
20090001919 NASA Stennis Space Center, Stennis Space Center, MS, United States
Design Evolution and Verification of the A-3 Chemical Steam Generator
Kirchner, Casey K.; [2009]; In English; AIAA JPC Conference, 2-5 Aug. 2009, Denver, CO, United States; Original contains color and black and white illustrations
Report No.(s): SSTI-2220-0175; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090001919
Following is an overview of the Chemical Steam Generator system selected to provide vacuum conditions for a new altitude test facility, the A-3 Test Stand at Stennis Space Center (SSC) in Bay St. Louis, MS. A-3 will serve as NASA s primary facility for altitude testing of the J-2X rocket engine, to be used as the primary propulsion device for the upper stages of the Ares launch vehicles. The Chemical Steam Generators (CSGs) will produce vacuum conditions in the test cell through the production and subsequent supersonic ejection of steam into a diffuser downstream of the J-2X engine nozzle exit. The Chemical Steam Generators chosen have a rich heritage of operation at rocket engine altitude test facilities since the days of the Apollo program and are still in use at NASA White Sands Test Facility (WSTF) in New Mexico. The generators at WSTF have been modified to a degree, but are still very close to the heritage design. The intent for the A-3 implementation is to maintain this heritage design as much as possible, making minimal updates only where necessary to substitute for obsolete parts and to increase reliability. Reliability improvements are especially desired because the proposed system will require 27 generators, which is nine times the largest system installed in the 1960s. Improvements were suggested by the original design firm, Reaction Motors, by NASA SSC and NASA WSTF engineers, and by the A-3 test stand design contractor, Jacobs Technology, Inc. (JTI). This paper describes the range of improvements made to the design to date, starting with the heritage generator and the minor modifications made over time at WSTF, to the modernized configuration which will be used at A-3. The paper will discuss NASA s investment in modifications to SSC s E-2 test facility fire a full-scale Chemical Steam Generator in advance of the larger steam system installation at A-3. Risk mitigation testing will be performed in early 2009 at this test facility to verify that the CSGs operate as expected. The generator which will undergo this testing is of the most recent A-3 configuration, and will be instrumented far in excess of what is normally required for operation. The extra data will allow for easier troubleshooting and more complete knowledge of expected generator performance. In addition, the early testing will give SSC personnel experience in operating the CSG systems, which will expedite the process of installation and activation at A-3. Each Chemical Steam Generator is supported by a complement of valves, instruments, and flow control devices, with the entire assembly called a "module." The generators will be installed in groups of three, historically called "units". A module is so called because of its modular ability to be replaced or serviced without disturbing the other two modules installed on the same unit. A module is pictured in Figure 1, shown with its generator secured by white bands in its shipping (vs. installed) configuration. The heritage system at WSTF is composed of a single unit (three generator modules), pictured in Figure 2 as it was installed in 1965. In contrast, A-3 will have nine units operating in parallel to achieve vacuum conditions appropriate for testing the J-2X engine. Each of the combustors operates in two modes and achieves the so-called "full-steam" mode after all three of its stages ignite. Ignition of the first stage is achieved by exciting a spark plug; the second stage and main stage are lit by the flame front of the previous stage. The main stage burns approximately 97% of the total propellant flow and uses the heat energy to vaporize water into superheated steam. While the main stage remains unlit, the combustor is in so-called "idle" mode. In the WSTF system, this idle mode is not optimized for water usage, and does not need to be, as the water is pumped from a large reservoir. The water supply at A-3 will be contained in tanks with finite volume, so water optimization is preferred for the modnized configuration. Multiple solutions for this issue have been proposed, with the leading concept being a change to the operational definition of "idle mode," with the generator running in a lower heat flux condition.
Author
VACUUM TESTS; TEST STANDS; ALTITUDE TESTS; STEAM; ROCKET ENGINES; CONTROL EQUIPMENT; ENGINE TESTS
Additions to the NASA Aeronautics and Space Database as of 01/26/2009
20090001943 NASA Marshall Space Flight Center, Huntsville, AL, United States
Development and Testing of a Sorbent-Based Atmosphere Revitalization System for the Crew Exploration Vehicle 2007/2008
Knox, James C.; Howard, David; Miller, Lee; June 29, 2008; In English; 38th International Conference on Environmental Systems, 29 Jun. - 2 Jul. 2008, San Francisco, CA, United States; Original contains color illustrations
Report No.(s): 2008-01-2082; Copyright; Avail.: CASI: A03, Hardcopy
The design of a Vacuum-Swing Adsorption (VSA) system to remove metabolic water and metabolic carbon dioxide from the Orion Crew Exploration Vehicle (CEV) atmosphere is presented. The approach for Orion is a VSA system that removes not only 100 percent of the metabolic CO2 from the atmosphere, but also 100% of the metabolic water as well, a technology approach that has not been used in previous spacecraft life support systems. The design and development of the Sorbent Based Atmosphere Regeneration (SBAR) system, including test articles, a facility test stand, and full-scale testing in late 2007 and early 2008 is discussed.
Author
LIFE SUPPORT SYSTEMS; CREW EXPLORATION VEHICLE; ADSORPTION; VACUUM; METABOLISM
20090001944 NASA Johnson Space Center, Houston, TX, United States
Ambiguous Tilt and Translation Motion Cues after Space Flight and Otolith Assessment during Post-Flight Re-Adaptation
Wood, Scott J.; Clarke, A. H.; Harm, D. L.; Rupert, A. H.; Clement, G. R.; [2009]; In English; Human Research Program Investigators' Workshop, 2-4 Feb. 2009, League City, TX, United States
Contract(s)/Grant(s): DLR WB0729
Copyright; Avail.: CASI: A01, Hardcopy
Adaptive changes during space flight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation and perceptual illusions following Gtransitions. These studies are designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances following short duration space flights.
Derived from text
ATTITUDE (INCLINATION); CUES; OTOLITH ORGANS; VESTIBULES; MANNED SPACE FLIGHT; AEROSPACE MEDICINE
20090002118 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Eta Car: The Good, the Bad and the Ugly of Nebular and Stellar Confusion
Gull, T.R.; Sonneborn, G.; Jensen, A.G.; Nielsen, K.E.; Vieira Kover, G.; Hillier, D.J.; July 13, 2008; In English; FUSE Conference, 13 Jul. - 22 Oct. 2008, Maryland, United States; Original contains black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Observations in the far-UV provide a unique opportunity to investigate the very massive star Eta Car and its hot binary companion, Eta Car B. Eta Car was observed with FUSE over a large portion of the 5.54 year spectroscopic period before and after the 2003.5 minimum. The observed spectrum is defined by strong stellar wind signatures, primarily from Eta Car A, complicated by the strong absorptions of the ejecta surrounding Eta Car plus interstellar absorption. The Homunculus and Little Homunculus are massive bipolar ejecta historically associable with LBV outbursts in the 1840s and the 1890s and are linked to absorptions at -513 and -146 km/s, respectively. The FUSE spectra are confused by the extended nebulosity and thermal drifting of the FUSE co-pointed instruments. Interpretation is further complicated by two B-stars sufficiently close to h Car to be included most of the time in the large FUSE aperture. Followup observations partially succeeded in obtaining spectra of at least one of these B-stars through the smaller apertures, allowing potential separation of the B-star contributions and h Car. A complete analysis of all available spectra is currently underway. Our ultimate goals are to directly detect the hot secondary star if possible with FUSE and to identify the absorption contributions to the overall spectrum especially of the stellar members and the massive ejecta.
Author
B STARS; HOT STARS; MASSIVE STARS; EJECTA; SPECTROSCOPY; BIPOLARITY
20090002204 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Accuracy Assessment and Correction of Vaisala RS92 Radiosonde Water Vapor Measurements
Whiteman, David N.; Miloshevich, Larry M.; Vomel, Holger; Leblanc, Thierry; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNX06AC79G
Copyright; Avail.: CASI: A04, Hardcopy
Relative humidity (RH) measurements from Vaisala RS92 radiosondes are widely used in both research and operational applications, although the measurement accuracy is not well characterized as a function of its known dependences on height, RH, and time of day (or solar altitude angle). This study characterizes RS92 mean bias error as a function of its dependences by comparing simultaneous measurements from RS92 radiosondes and from three reference instruments of known accuracy. The cryogenic frostpoint hygrometer (CFH) gives the RS92 accuracy above the 700 mb level; the ARM microwave radiometer gives the RS92 accuracy in the lower troposphere; and the ARM SurTHref system gives the RS92 accuracy at the surface using 6 RH probes with NIST-traceable calibrations. These RS92 assessments are combined using the principle of Consensus Referencing to yield a detailed estimate of RS92 accuracy from the surface to the lowermost stratosphere. An empirical bias correction is derived to remove the mean bias error, yielding corrected RS92 measurements whose mean accuracy is estimated to be +/-3% of the measured RH value for nighttime soundings and +/-4% for daytime soundings, plus an RH offset uncertainty of +/-0.5%RH that is significant for dry conditions. The accuracy of individual RS92 soundings is further characterized by the 1-sigma "production variability," estimated to be +/-1.5% of the measured RH value. The daytime bias correction should not be applied to cloudy daytime soundings, because clouds affect the solar radiation error in a complicated and uncharacterized way.
Author
ACCURACY; WATER VAPOR; HUMIDITY MEASUREMENT; RADIOSONDES; CRYOGENICS; ESTIMATING; SOLAR RADIATION; CALIBRATING
20090002228 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Demonstration of Aerosol Property Profiling by Multi-wavelength Lidar Under Varying Relative Humidity Conditions
Whiteman, D.N.; Veselovskii, I.; Kolgotin, A.; Korenskii, M.; Andrews, E.; [2008]; In English
Copyright; Avail.: CASI: A04, Hardcopy
The feasibility of using a multi-wavelength Mie-Raman lidar based on a tripled Nd:YAG laser for profiling aerosol physical parameters in the planetary boundary layer (PBL) under varying conditions of relative humidity (RH) is studied. The lidar quantifies three aerosol backscattering and two extinction coefficients and from these optical data the particle parameters such as concentration, size and complex refractive index are retrieved through inversion with regularization. The column-integrated, lidar-derived parameters are compared with results from the AERONET sun photometer. The lidar and sun photometer agree well in the characterization of the fine mode parameters, however the lidar shows less sensitivity to coarse mode. The lidar results reveal a strong dependence of particle properties on RH. The height regions with enhanced RH are characterized by an increase of backscattering and extinction coefficient and a decrease in the Angstrom exponent coinciding with an increase in the particle size. We present data selection techniques useful for selecting cases that can support the calculation of hygroscopic growth parameters using lidar. Hygroscopic growth factors calculated using these techniques agree with expectations despite the lack of co-located radiosonde data. Despite this limitation, the results demonstrate the potential of multi-wavelength Raman lidar technique for study of aerosol humidification process.
Author
AEROSOLS; OPTICAL RADAR; PLANETARY BOUNDARY LAYER; YAG LASERS; NEODYMIUM LASERS; ATTENUATION COEFFICIENTS; RADIOSONDES
20090002404 NASA Johnson Space Center, Houston, TX, United States
Columbia Crew Survival Investigation Report
[2009]; In English; Original contains color and black and white illustrations
Report No.(s): NASA/SP-2008-565; No Copyright; Avail.: CASI: A17, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002404
NASA commissioned the Columbia Accident Investigation Board (CAIB) to conduct a thorough review of both the technical and the organizational causes of the loss of the Space Shuttle Columbia and her crew on February 1, 2003. The accident investigation that followed determined that a large piece of insulating foam from Columbia s external tank (ET) had come off during ascent and struck the leading edge of the left wing, causing critical damage. The damage was undetected during the mission. The CAIB's findings and recommendations were published in 2003 and are available on the web at http://caib.nasa.gov/. NASA responded to the CAIB findings and recommendations with the Space Shuttle Return to Flight Implementation Plan. Significant enhancements were made to NASA's organizational structure, technical rigor, and understanding of the flight environment. The ET was redesigned to reduce foam shedding and eliminate critical debris. In 2005, NASA succeeded in returning the space shuttle to flight. In 2010, the space shuttle will complete its mission of assembling the International Space Station and will be retired to make way for the next generation of human space flight vehicles: the Constellation Program. The Space Shuttle Program recognized the importance of capturing the lessons learned from the loss of Columbia and her crew to benefit future human exploration, particularly future vehicle design. The program commissioned the Spacecraft Crew Survival Integrated Investigation Team (SCSIIT). The SCSIIT was asked to perform a comprehensive analysis of the accident, focusing on factors and events affecting crew survival, and to develop recommendations for improving crew survival for all future human space flight vehicles. To do this, the SCSIIT investigated all elements of crew survival, including the design features, equipment, training, and procedures intended to protect the crew. This report documents the SCSIIT findings, conclusions, and recommendations.
Author
INTERNATIONAL SPACE STATION; COLUMBIA (ORBITER); AIRCRAFT ACCIDENT INVESTIGATION; SPACECRAFT SURVIVABILITY; SPACECREWS; NASA SPACE PROGRAMS; MANNED SPACE FLIGHT; SPACE TRANSPORTATION SYSTEM
20090002407 NASA Marshall Space Flight Center, Huntsville, AL, United States
Combustion Devices CFD Team Analyses Review
Rocker, Marvin; March 07, 2008; In English; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002407
A variety of CFD simulations performed by the Combustion Devices CFD Team at Marshall Space Flight Center will be presented. These analyses were performed to support Space Shuttle operations and Ares-1 Crew Launch Vehicle design. Results from the analyses will be shown along with pertinent information on the CFD codes and computational resources used to obtain the results. Six analyses will be presented - two related to the Space Shuttle and four related to the Ares I-1 launch vehicle now under development at NASA. First, a CFD analysis of the flow fields around the Space Shuttle during the first six seconds of flight and potential debris trajectories within those flow fields will be discussed. Second, the combusting flows within the Space Shuttle Main Engine's main combustion chamber will be shown. For the Ares I-1, an analysis of the performance of the roll control thrusters during flight will be described. Several studies are discussed related to the J2-X engine to be used on the upper stage of the Ares I-1 vehicle. A parametric study of the propellant flow sequences and mixture ratios within the GOX/GH2 spark igniters on the J2-X is discussed. Transient simulations will be described that predict the asymmetric pressure loads that occur on the rocket nozzle during the engine start as the nozzle fills with combusting gases. Simulations of issues that affect temperature uniformity within the gas generator used to drive the J-2X turbines will described as well, both upstream of the chamber in the injector manifolds and within the combustion chamber itself.
Author
ARES 1 LAUNCH VEHICLE; COMPUTATIONAL FLUID DYNAMICS; SIMULATION; COMBUSTION CHAMBERS; IGNITION SYSTEMS; MANNED SPACE FLIGHT
Additions to the NASA Aeronautics and Space Database as of 01/27/2009
20090002465 Toledo Univ., OH United States
Control System for Bearingless Motor-generator
Kascak, Peter E., Inventor; Jansen, Ralph H., Inventor; Dever, Timothy P., Inventor; November 25, 2008; In English
Contract(s)/Grant(s): NCC3-916; NCC3-924
Patent Info.: December 15, 2005US-Patent-7,456,537; US-Patent-Appl-SN-11/304,359
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002465
A control system for an electromagnetic rotary drive for bearingless motor-generators comprises a winding configuration comprising a plurality of individual pole pairs through which phase current flows, each phase current producing both a lateral force and a torque. A motor-generator comprises a stator, a rotor supported for movement relative to the stator, and a control system. The motor-generator comprises a winding configuration supported by the stator. The winding configuration comprises at least three pole pairs through which phase current flows resulting in three three-phase systems. Each phase system has a first rotor reference frame axis current that produces a levitating force with no average torque and a second rotor reference frame axis current that produces torque.
Official Gazette of the U.S. Patent and Trademark Office
MECHANICAL DRIVES; BEARINGLESS ROTORS; CONTROL SYSTEMS DESIGN; MOTORS
20090002466 NASA, Washington, DC, United States
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008)
2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/NP-2008-OL-527-HQ; No Copyright; Avail.: CASI: A10, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002466
NASA Technology Benefiting Society subject headings include: Health and Medicine, Transportation, Public Safety, Consumer, Home and Recreation, Environmental and Agricultural Resources, Computer Technology, and Industrial Productivity. Other topics covered include: Aeronautics and Space Activities, Education News, Partnership News, and the Innovative Partnership Program.
Author
COMPUTER SYSTEMS DESIGN; TRANSPORTATION; RECREATION; PRODUCTIVITY; HEALTH; EDUCATION; AGRICULTURE
20090002467 Aspen Aerogels, Inc., Northborough, MA, United States
Aerogels Insulate Missions and Consumer Products
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 108-10; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002467
Aspen Aerogels, of Northborough, Massachusetts, worked with NASA through an SBIR contract with Kennedy Space Center to develop a robust, flexible form of aerogel for cryogenic insulation for space shuttle launch applications. The company has since used the same manufacturing process developed under the SBIR award to expand its product offerings into the more commercial realms, making the naturally fragile aerogel available for the first time as a standard insulation that can be handled and installed just like standard insulation.
Author
AEROGELS; CRYOGENICS; INSULATION; SPACE SHUTTLES
20090002468 BAE Systems, United States
Integrated Circuit Chip Improves Network Efficiency
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 144-14; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002468
Prior to 1999 and the development of SpaceWire, a standard for high-speed links for computer networks managed by the European Space Agency (ESA), there was no high-speed communications protocol for flight electronics. Onboard computers, processing units, and other electronics had to be designed for individual projects and then redesigned for subsequent projects, which increased development periods, costs, and risks. After adopting the SpaceWire protocol in 2000, NASA implemented the standard on the Swift mission, a gamma ray burst-alert telescope launched in November 2004. Scientists and developers on the James Webb Space Telescope further developed the network version of SpaceWire. In essence, SpaceWire enables more science missions at a lower cost, because it provides a standard interface between flight electronics components; new systems need not be custom built to accommodate individual missions, so electronics can be reused. New protocols are helping to standardize higher layers of computer communication. Goddard Space Flight Center improved on the ESA-developed SpaceWire by enabling standard protocols, which included defining quality of service and supporting plug-and-play capabilities. Goddard upgraded SpaceWire to make the routers more efficient and reliable, with features including redundant cables, simultaneous discrete broadcast pulses, prevention of network blockage, and improved verification. Redundant cables simplify management because the user does not need to worry about which connection is available, and simultaneous broadcast signals allow multiple users to broadcast low-latency side-band signal pulses across the network using the same resources for data communication. Additional features have been added to the SpaceWire switch to prevent network blockage so that more robust networks can be designed. Goddard s verification environment for the link-and-switch implementation continuously randomizes and tests different parts, constantly anticipating situations, which helps improve communications reliability. It has been tested in many different implementations for compatibility.
Author
INTEGRATED CIRCUITS; CHIPS; AIRBORNE/SPACEBORNE COMPUTERS; COMMUNICATION EQUIPMENT; COMPUTER NETWORKS; HIGH SPEED
20090002469 Medtronic, Inc., Minneapolis, MN, United States
Polymer Coats Leads on Implantable Medical Device
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 52-5; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002469
Langley Research Center s Soluble Imide (LaRC-SI) was discovered by accident. While researching resins and adhesives for advanced composites for high-speed aircraft, Robert Bryant, a Langley engineer, noticed that one of the polymers he was working with did not behave as predicted. After putting the compound through a two-stage controlled chemical reaction, expecting it to precipitate as a powder after the second stage, he was surprised to see that the compound remained soluble. This novel characteristic ended up making this polymer a very significant finding, eventually leading Bryant and his team to win several NASA technology awards, and an "R&D 100" award. The unique feature of this compound is the way that it lends itself to easy processing. Most polyimides (members of a group of remarkably strong and incredibly heat- and chemical-resistant polymers) require complex curing cycles before they are usable. LaRC-SI remains soluble in its final form, so no further chemical processing is required to produce final materials, like thin films and varnishes. Since producing LaRC-SI does not require complex manufacturing techniques, it has been processed into useful forms for a variety of applications, including mechanical parts, magnetic components, ceramics, adhesives, composites, flexible circuits, multilayer printed circuits, and coatings on fiber optics, wires, and metals. Bryant s team was, at the time, heavily involved with the aircraft polymer project and could not afford to further develop the polymer resin. Believing it was worth further exploration, though, he developed a plan for funding development and submitted it to Langley s chief scientist, who endorsed the experimentation. Bryant then left the high-speed civil transport project to develop LaRC-SI. The result is an extremely tough, lightweight thermoplastic that is not only solvent-resistant, but also has the ability to withstand temperature ranges from cryogenic levels to above 200 C. The thermoplastic s unique characteristics lend it to many commercial applications; uses that Bryant believed would ultimately benefit industry and the Nation. "LaRC-SI," he explains, "is a product created in a government laboratory, funded with money from the tax-paying public. What we discovered helps further the economic competitiveness of the United States, and it was our goal to initiate the technology transfer process to ensure that our work benefited the widest range of people." Several NASA centers, including Langley, have explored methods for using LaRC-SI in a number of applications from radiation shielding and as an adhesive to uses involving replacement of conventional rigid circuit boards. In the commercial realm, LaRC-SI can now be found in several commercial products, including the thin-layer composite unimorph ferroelectric driver and sensor (THUNDER) piezoelectric actuator, another "R&D 100" award winner (Spinoff 2005).
Author
POLYIMIDES; THERMOPLASTICITY; RADIATION SHIELDING; POWDER (PARTICLES); CERAMICS; MEDICAL SCIENCE; COMPOSITE MATERIALS
20090002470 Paragon Space Development Corp., AZ, United States
Space Suit Technologies Protect Deep-Sea Divers
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 80-8; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002470
Working on NASA missions allows engineers and scientists to hone their skills. Creating devices for the high-stress rigors of space travel pushes designers to their limits, and the results often far exceed the original concepts. The technologies developed for the extreme environment of space are often applicable here on Earth. Some of these NASA technologies, for example, have been applied to the breathing apparatuses worn by firefighters, the fire-resistant suits worn by racecar crews, and, most recently, the deep-sea gear worn by U.S. Navy divers.
Author
DIVING (UNDERWATER); SPACE SUITS; NASA PROGRAMS; FLAME RETARDANTS
20090002471 Delphi Corp., United States; Michigan Research Institute, Ann Arbor, MI, United States
Novel Process Revolutionizes Welding Industry
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 148-14; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002471
Glenn Research Center, Delphi Corporation, and the Michigan Research Institute entered into a research project to study the use of Deformation Resistance Welding (DRW) in the construction and repair of stationary structures with multiple geometries and dissimilar materials, such as those NASA might use on the Moon or Mars. Traditional welding technologies are burdened by significant business and engineering challenges, including high costs of equipment and labor, heat-affected zones, limited automation, and inconsistent quality. DRW addresses each of those issues, while drastically reducing welding, manufacturing, and maintenance costs.
Derived from text
WELDING; DEFORMATION; TECHNOLOGY UTILIZATION
20090002472 Endevco Corp., San Juan Capistrano, CA, United States
Sensors Increase Productivity in Harsh Environments
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 150-15; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002472
California's San Juan Capistrano-based Endevco Corporation licensed three patents covering high-temperature, harsh-environment silicon carbide (Si-C) pressure sensors from Glenn Research Center. The company is exploring their use in government markets, as well as in commercial markets, including commercial jet testing, deep well drilling applications where pressure and temperature increase with drilling depth, and in automobile combustion chambers.
Derived from text
PRESSURE SENSORS; SILICON CARBIDES; AIRCRAFT ENGINES; COMBUSTION CHAMBERS; ENGINE TESTS; HIGH TEMPERATURE ENVIRONMENTS; RESEARCH AND DEVELOPMENT; AEROSPACE INDUSTRY
20090002473 inXitu, Mountain View, CA, United States
Portable Device Analyzes Rocks and Minerals
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 152-15; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002473
inXitu Inc., of Mountain View, California, entered into a Phase II SBIR contract with Ames Research Center to develop technologies for the next generation of scientific instruments for materials analysis. The work resulted in a sample handling system that could find a wide range of applications in research and industrial laboratories as a means to load powdered samples for analysis or process control. Potential industries include chemical, cement, inks, pharmaceutical, ceramics, and forensics. Additional applications include characterizing materials that cannot be ground to a fine size, such as explosives and research pharmaceuticals.
Derived from text
PORTABLE EQUIPMENT; PLANETARY GEOLOGY; MINERALOGY; GEOCHEMISTRY; SAMPLING
20090002474 Techshot, Inc., Greenville, IN, United States
Magnetic Separator Enhances Treatment Possibilities
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 62-6; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002474
Since the earliest missions in space, NASA specialists have performed experiments in low gravity. Protein crystal growth, cell and tissue cultures, and separation technologies such as electrophoresis and magnetophoresis have been studied on Apollo 14, Apollo 16, STS-107, and many other missions. Electrophoresis and magnetophoresis, respectively, are processes that separate substances based on the electrical charge and magnetic field of a molecule or particle. Electrophoresis has been studied on over a dozen space shuttle flights, leading to developments in electrokinetics, which analyzes the effects of electric fields on mass transport (atoms, molecules, and particles) in fluids. Further studies in microgravity will continue to improve these techniques, which researchers use to extract cells for various medical treatments and research.
Author
MAGNETIC FIELDS; SEPARATORS; ELECTROKINETICS; ELECTRIC CHARGE; MICROGRAVITY; PROTEIN CRYSTAL GROWTH; MASS TRANSFER; EXTRACTION
20090002475 Barrett Technology, Inc., Cambridge, MA, United States
Robotics Offer Newfound Surgical Capabilities
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 46-4; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002475
Barrett Technology Inc., of Cambridge, Massachusetts, completed three Phase II Small Business Innovation Research (SBIR) contracts with Johnson Space Center, during which the company developed and commercialized three core technologies: a robotic arm, a hand that functions atop the arm, and a motor driver to operate the robotics. Among many industry uses, recently, an adaptation of the arm has been cleared by the U.S. Food and Drug Administration (FDA) for use in a minimally invasive knee surgery procedure, where its precision control makes it ideal for inserting a very small implant.
Author
INTERNATIONAL SPACE STATION; ROBOTICS; AEROSPACE MEDICINE; SURGERY
20090002476 DesignAmerica, Inc., Annapolis, MD, United States
Program Assists Satellite Designers
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 126-12; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002476
Annapolis, Maryland-based designAmerica Inc., a small aerospace company specializing in the development and delivery of ground control systems for satellites and instrumentation, assisted Goddard Space Flight Center in the development of the ASIST software, a real-time command and control system for spacecraft development, integration, and operations. It was designed to be fully functional across a broad spectrum of satellites and instrumentation, while also being user friendly. The company now has rights to commercial use of the program and is offering it to government and industry satellite designers.
Author
APPLICATIONS PROGRAMS (COMPUTERS); SATELLITE DESIGN; CONTROL SYSTEMS DESIGN; COMMAND AND CONTROL; GROUND BASED CONTROL; COMMERCIAL OFF-THE-SHELF PRODUCTS
20090002477 Big Horn Valve, Inc., Sheridan, WY, United States
Innovative Stemless Valve Eliminates Emissions
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 120-12; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002477
Big Horn Valve Inc. (BHVI), of Sheridan, Wyoming, won a series of SBIR and Small Business Technology Transfer (STTR) contracts with Kennedy Space Center and Marshall Space Flight Center to explore and develop a revolutionary valve technology. BHVI developed a low-mass, high-efficiency, leak-proof cryogenic valve using composites and exotic metals, and had no stem-actuator, few moving parts, with an overall cylindrical shape. The valve has been installed at a methane coal gas field, and future applications are expected to include in-flight refueling of military aircraft, high-volume gas delivery systems, petroleum refining, and in the nuclear industry.
Author
VALVES; CRYOGENIC FLUIDS; FLUID MANAGEMENT; TECHNOLOGY UTILIZATION; RESEARCH AND DEVELOPMENT; CRYOGENICS; NASA PROGRAMS
20090002478 DATASTAR, Inc., Picayune, MS, United States
Web-Based Mapping Puts the World at Your Fingertips
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 122-12; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002478
NASA's award-winning Earth Resources Laboratory Applications Software (ELAS) package was developed at Stennis Space Center. Since 1978, ELAS has been used worldwide for processing satellite and airborne sensor imagery data of the Earth's surface into readable and usable information. DATASTAR Inc., of Picayune, Mississippi, has used ELAS software in the DATASTAR Image Processing Exploitation (DIPEx) desktop and Internet image processing, analysis, and manipulation software. The new DIPEx Version III includes significant upgrades and improvements compared to its esteemed predecessor. A true World Wide Web application, this product evolved with worldwide geospatial dimensionality and numerous other improvements that seamlessly support the World Wide Web version.
Author
APPLICATIONS PROGRAMS (COMPUTERS); SATELLITE IMAGERY; AERIAL PHOTOGRAPHY; IMAGE PROCESSING; WORLD WIDE WEB; MAPPING; REMOTE SENSING; DATA RETRIEVAL
20090002479 Viaspace, Inc., Pasadena, CA, United States
Software Analyzes Complex Systems in Real Time
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 130-13; In English; Original contains color and black and white illustrations
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Expert system software programs, also known as knowledge-based systems, are computer programs that emulate the knowledge and analytical skills of one or more human experts, related to a specific subject. SHINE (Spacecraft Health Inference Engine) is one such program, a software inference engine (expert system) designed by NASA for the purpose of monitoring, analyzing, and diagnosing both real-time and non-real-time systems. It was developed to meet many of the Agency s demanding and rigorous artificial intelligence goals for current and future needs. NASA developed the sophisticated and reusable software based on the experience and requirements of its Jet Propulsion Laboratory s (JPL) Artificial Intelligence Research Group in developing expert systems for space flight operations specifically, the diagnosis of spacecraft health. It was designed to be efficient enough to operate in demanding real time and in limited hardware environments, and to be utilized by non-expert systems applications written in conventional programming languages. The technology is currently used in several ongoing NASA applications, including the Mars Exploration Rovers and the Spacecraft Health Automatic Reasoning Pilot (SHARP) program for the diagnosis of telecommunication anomalies during the Neptune Voyager Encounter. It is also finding applications outside of the Space Agency.
Author
COMPUTER PROGRAMS; COMPLEX SYSTEMS; SOFTWARE ENGINEERING; AUTOMATIC PILOTS; ARTIFICIAL INTELLIGENCE; FLIGHT OPERATIONS; HEALTH
20090002480 Vexcel Corp., Boulder, CO, United States
Wireless Sensor Network Handles Image Data
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 132-13; In English; Original contains color illustrations
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To relay data from remote locations for NASA s Earth sciences research, Goddard Space Flight Center contributed to the development of "microservers" (wireless sensor network nodes), which are now used commercially as a quick and affordable means to capture and distribute geographical information, including rich sets of aerial and street-level imagery. NASA began this work out of a necessity for real-time recovery of remote sensor data. These microservers work much like a wireless office network, relaying information between devices. The key difference, however, is that instead of linking workstations within one office, the interconnected microservers operate miles away from one another. This attribute traces back to the technology s original use: The microservers were originally designed for seismology on remote glaciers and ice streams in Alaska, Greenland, and Antarctica-acquiring, storing, and relaying data wirelessly between ground sensors. The microservers boast three key attributes. First, a researcher in the field can establish a "managed network" of microservers and rapidly see the data streams (recovered wirelessly) on a field computer. This rapid feedback permits the researcher to reconfigure the network for different purposes over the course of a field campaign. Second, through careful power management, the microservers can dwell unsupervised in the field for up to 2 years, collecting tremendous amounts of data at a research location. The third attribute is the exciting potential to deploy a microserver network that works in synchrony with robotic explorers (e.g., providing ground truth validation for satellites, supporting rovers as they traverse the local environment). Managed networks of remote microservers that relay data unsupervised for up to 2 years can drastically reduce the costs of field instrumentation and data rec
Author
DATA ACQUISITION; REMOTE SENSORS; DATA FLOW ANALYSIS; EARTH SCIENCES; SEISMOLOGY; REAL TIME OPERATION
20090002481 Vision Research Corp., Birmingham, AL, United States
Photorefraction Screens Millions for Vision Disorders
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 58-5; In English; Original contains color illustrations
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Who would have thought that stargazing in the 1980s would lead to hundreds of thousands of schoolchildren seeing more clearly today? Collaborating with research ophthalmologists and optometrists, Marshall Space Flight Center scientists Joe Kerr and the late John Richardson adapted optics technology for eye screening methods using a process called photorefraction. Photorefraction consists of delivering a light beam into the eyes where it bends in the ocular media, hits the retina, and then reflects as an image back to a camera. A series of refinements and formal clinical studies followed their highly successful initial tests in the 1980s. Evaluating over 5,000 subjects in field tests, Kerr and Richardson used a camera system prototype with a specifically angled telephoto lens and flash to photograph a subject s eye. They then analyzed the image, the cornea and pupil in particular, for irregular reflective patterns. Early tests of the system with 1,657 Alabama children revealed that, while only 111 failed the traditional chart test, Kerr and Richardson s screening system found 507 abnormalities.
Author
PHOTOGRAPHS; EYE (ANATOMY); OPHTHALMOLOGY; LIGHT BEAMS; CAMERAS; CORNEA; PUPILS; RETINA
20090002482 Earthmine, Inc., Berkeley, CA, United States
Mars Mapping Technology Brings Main Street to Life
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 140-14; In English; Original contains color illustrations
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The Red Planet has long held a particular hold on the human psyche. From the Roman god of war to Orson Welles infamous Halloween broadcast, our nearest planetary neighbor has been viewed with curiosity, suspicion, and awe. Pictures of Mars from 1965 to the present reveal familiar landscapes while also challenging our perceptions and revising our understanding of the processes at work in planets. Frequent discoveries have forced significant revisions to previous theories. Although Mars shares many familiar features with Earth, such as mountains, plains, valleys, and polar ice, the conditions on Mars can vary wildly from those with which we are familiar. The apparently cold, rocky, and dusty wasteland seen through the eyes of spacecraft and Martian probes hints at a dynamic past of volcanic activity, cataclysmic meteors, and raging waters. New discoveries continue to revise our view of our next-door neighbor, and further exploration is now paving the way for a human sortie to the fourth stone from the Sun. NASA s Mars Exploration Program, a long-term effort of robotic exploration, utilizes wide-angle stereo cameras mounted on NASA s twin robot geologists, the Mars Exploration Rovers (MERs), launched in 2003. The rovers, named "Spirit" and "Opportunity," celebrated 4 Earth years of exploration on January 3, 2008, and have sent back a wealth of information on the terrain and composition of the Martian surface. Their marathon performance has far outlasted the intended 90 days of operation, and the two intrepid explorers promise more images and data.
Author
MARS EXPLORATION; GEOLOGICAL SURVEYS; PLANETARY MAPPING; MARS SURFACE; ROVING VEHICLES; ROBOTICS
20090002483 Deeya Energy, Inc., Silicon Valley, CA, United States
Battery Technology Stores Clean Energy
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 114-11; In English; Original contains color illustrations
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Headquartered in Fremont, California, Deeya Energy Inc. is now bringing its flow batteries to commercial customers around the world after working with former Marshall Space Flight Center scientist, Lawrence Thaller. Deeya's liquid-cell batteries have higher power capability than Thaller's original design, are less expensive than lead-acid batteries, are a clean energy alternative, and are 10 to 20 times less expensive than nickel-metal hydride batteries, lithium-ion batteries, and fuel cell options.
Author
CLEAN ENERGY; LEAD ACID BATTERIES; TECHNOLOGY UTILIZATION; METAL HYDRIDES
20090002484 Luna Technologies, Inc., Blacksburg, VA, United States
Fiber Optic Sensing Monitors Strain and Reduces Costs
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 82-8; In English; Original contains color illustrations
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In applications where stress on a structure may vary widely and have an unknown impact on integrity, a common engineering strategy has been overbuilding to ensure a sufficiently robust design. While this may be appropriate in applications where weight concerns are not paramount, space applications demand a bare minimum of mass, given astronomical per-pound launch costs. For decades, the preferred solution was the tactic of disassembly and investigation between flights. Knowing there must be a better way, Dr. Mark Froggatt, of Langley Research Center, explored alternate means of monitoring stresses and damage to the space shuttle. While a tear-it-apart-and-have-a-look strategy was effective, it was also a costly and time consuming process that risked further stresses through the very act of disassembly and reassembly. An alternate way of monitoring the condition of parts under the enormous stresses of space flight was needed. Froggatt and his colleagues at Langley built an early-warning device to provide detailed information about even minuscule cracks and deformations by etching a group of tiny lines, or grating, on a fiber optic cable five-thousandths of an inch thick with ultraviolet light. By then gluing the fiber to the side of a part, such as a fuel tank, and shining a laser beam down its length, reflected light indicated which gratings were under stress. Inferring this data from measurements in light rather than in bonded gauges saved additional weight. Various shuttle components now employ the ultrasonic dynamic vector stress sensor (UDVSS), allowing stress detection by measuring light beamed from a built-in mini-laser. By measuring changes in dynamic directional stress occurring in a material or structure, and including phase-locked loop, synchronous amplifier, and contact probe, the UDVSS proved especially useful among manufacturers of aerospace and automotive structures for stress testing and design evaluation. Engineers could ensure safety in airplanes and spaceships with a narrower, not overbuilt, margin of safety. For this development, in 1997, Discover Magazine named Froggatt a winner in the "Eighth Annual Awards for Technological Innovation" from more than 4,000 entries.
Author
FIBER OPTICS; STRESS ANALYSIS; ULTRAVIOLET RADIATION; EARLY WARNING SYSTEMS; DYNAMIC LOADS; DEFORMATION; MEASURING INSTRUMENTS; DETECTION
20090002485 Walter Reed Army Medical Center, Washington, DC, United States
Robotic Joints Support Horses and Humans
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 56-5; In English; Original contains color illustrations
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A rehabilitative device first featured in Spinoff 2003 is not only helping human patients regain the ability to walk, but is now helping our four-legged friends as well. The late James Kerley, a prominent Goddard Space Flight Center researcher, developed cable-compliant mechanisms in the 1980s to enable sounding rocket assemblies and robots to grip or join objects. In cable-compliant joints (CCJs), short segments of cable connect structural elements, allowing for six directions of movement, twisting, alignment, and energy damping. Kerley later worked with Goddard s Wayne Eklund and Allen Crane to incorporate the cable-compliant mechanisms into a walker for human patients to support the pelvis and imitate hip joint movement.
Author
ROBOTICS; ELASTIC PROPERTIES; PATIENTS; JOINTS (ANATOMY); ROBOTS; HORSES
20090002486 Visual Programs, Inc., Richmond, VA, United States
Periodontal Probe Improves Exams, Alleviates Pain
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 60-6; In English; Original contains color illustrations
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Dentists, comedian Bill Cosby memorably mused, tell you not to pick your teeth with any sharp metal object. Then you sit in their chair, and the first thing they grab is an iron hook!" Conventional periodontal probing is indeed invasive, uncomfortable for the patient, and the results can vary greatly between dentists and even for repeated measurements by the same dentist. It is a necessary procedure, though, as periodontal disease is the most common dental disease, involving the loss of teeth by the gradual destruction of ligaments that hold teeth in their sockets in the jawbone. The disease usually results from an increased concentration of bacteria in the pocket, or sulcus, between the gums and teeth. These bacteria produce acids and other byproducts, which enlarge the sulcus by eroding the gums and the periodontal ligaments. The sulcus normally has a depth of 1 to 2 millimeters, but in patients with early stages of periodontal disease, it has a depth of 3 to 5 millimeters. By measuring the depth of the sulcus, periodontists can have a good assessment of the disease s progress. Presently, there are no reliable clinical indicators of periodontal disease activity, and the best available diagnostic aid, periodontal probing, can only measure what has already been lost. A method for detecting small increments of periodontal ligament breakdown would permit earlier diagnosis and intervention with less costly and time-consuming therapy, while overcoming the problems associated with conventional probing. The painful, conventional method for probing may be destined for the archives of dental history, thanks to the development of ultrasound probing technologies. The roots of ultrasound probes are in an ultrasound-based time-of-flight technique routinely used to measure material thickness and length in the Nondestructive Evaluation Sciences Laboratory at Langley Research Center. The primary applications of that technology have been for corrosion detection and bolt tension measurements (Spinoff 2005). This ultrasound measurement system was adapted to the Periodontal Structures Mapping System, invented at Langley by John A. Companion, under the supervision of Dr. Joseph S. Heyman. Support of the research and development that led to this invention was provided by NASA s Technology Applications Engineering Program and by the Naval Institute for Dental and Biomedical Research, in Great Lakes, Illinois.
Author
DENTISTRY; DIAGNOSIS; ULTRASONIC TESTS; NONDESTRUCTIVE TESTS; DISEASES
20090002487 Airtab, Loveland, CO, United States
Aerodynamics Research Revolutionizes Truck Design
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 70-7; In English; Original contains color and black and white illustrations
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During the 1970s and 1980s, researchers at Dryden Flight Research Center conducted numerous tests to refine the shape of trucks to reduce aerodynamic drag and improved efficiency. During the 1980s and 1990s, a team based at Langley Research Center explored controlling drag and the flow of air around a moving body. Aeroserve Technologies Ltd., of Ottawa, Canada, with its subsidiary, Airtab LLC, in Loveland, Colorado, applied the research from Dryden and Langley to the development of the Airtab vortex generator. Airtabs create two counter-rotating vortices to reduce wind resistance and aerodynamic drag of trucks, trailers, recreational vehicles, and many other vehicles.
Author
AERODYNAMICS; TRUCKS; AERODYNAMIC DRAG
20090002488 Hoh Aeronautics, Inc., Lomita, CA, United States
Advanced Control System Increases Helicopter Safety
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 68-6; In English; Original contains color illustrations
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With support and funding from a Phase II NASA SBIR project from Ames Research Center, Hoh Aeronautics Inc. (HAI), of Lomita, California, produced HeliSAS, a low-cost, lightweight, attitude-command-attitude-hold stability augmentation system (SAS) for civil helicopters and unmanned aerial vehicles. HeliSAS proved itself in over 160 hours of flight testing and demonstrations in a Robinson R44 Raven helicopter, a commercial helicopter popular with news broadcasting and police operations. Chelton Flight Systems, of Boise, Idaho, negotiated with HAI to develop, market, and manufacture HeliSAS, now available as the Chelton HeliSAS Digital Helicopter Autopilot.
Derived from text
HELICOPTERS; PILOTLESS AIRCRAFT; STABILITY AUGMENTATION; ATTITUDE CONTROL; AIRCRAFT CONTROL; AIRCRAFT SAFETY
20090002489 Celanese Corp. of America, New York, NY, United States
Polymer Fabric Protects Firefighters, Military, and Civilians
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 84-8; In English; Original contains color illustrations
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In 1967, NASA contracted with Celanese Corporation, of New York, to develop a line of PBI textiles for use in space suits and vehicles. In 2005, the PBI fiber and polymer business was sold to PBI Performance Products Inc., of Charlotte, North Carolina, under the ownership of the InterTech Group, of North Charleston, South Carolina. PBI Performance Products now offers two distinct lines: PBI, the original heat and flame resistant fiber; and Celazole, a family of high-temperature PBI polymers available in true polymer form. PBI is now used in numerous firefighting, military, motor sports, and other applications.
Derived from text
POLYBENZIMIDAZOLE; SYNTHETIC FIBERS; THERMAL PROTECTION; PROTECTIVE CLOTHING
20090002490 Radiant Images, Inc., Duvall, WA, United States
Software Simulates Sight: Flat Panel Mura Detection
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 136-13; In English; Original contains color illustrations
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In the increasingly sophisticated world of high-definition flat screen monitors and television screens, image clarity and the elimination of distortion are paramount concerns. As the devices that reproduce images become more and more sophisticated, so do the technologies that verify their accuracy. By simulating the manner in which a human eye perceives and interprets a visual stimulus, NASA scientists have found ways to automatically and accurately test new monitors and displays. The Spatial Standard Observer (SSO) software metric, developed by Dr. Andrew B. Watson at Ames Research Center, measures visibility and defects in screens, displays, and interfaces. In the design of such a software tool, a central challenge is determining which aspects of visual function to include while accuracy and generality are important, relative simplicity of the software module is also a key virtue. Based on data collected in ModelFest, a large cooperative multi-lab project hosted by the Optical Society of America, the SSO simulates a simplified model of human spatial vision, operating on a pair of images that are viewed at a specific viewing distance with pixels having a known relation to luminance. The SSO measures the visibility of foveal spatial patterns, or the discriminability of two patterns, by incorporating only a few essential components of vision. These components include local contrast transformation, a contrast sensitivity function, local masking, and local pooling. By this construction, the SSO provides output in units of "just noticeable differences" (JND) a unit of measure based on the assumed smallest difference of sensory input detectable by a human being. Herein is the truly amazing ability of the SSO, while conventional methods can manipulate images, the SSO models human perception. This set of equations actually defines a mathematical way of working with an image that accurately reflects the way in which the human eye and mind behold a stimulus. The SSO is intended for a wide variety of applications, such as evaluating vision from unmanned aerial vehicles, measuring visibility of damage to aircraft and to the space shuttles, predicting outcomes of corrective laser eye surgery, inspecting displays during the manufacturing process, estimating the quality of compressed digital video, evaluating legibility of text, and predicting discriminability of icons or symbols in a graphical user interface.
Author
DISPLAY DEVICES; GRAPHICAL USER INTERFACE; TELEVISION SYSTEMS; VIEWING; VISUAL STIMULI; VIDEO COMPRESSION; PIXELS
20090002491 iSagacity, Inc., Portland, ME, United States
Inductive System Monitors Tasks
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 138-13; In English; Original contains color illustrations
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The Inductive Monitoring System (IMS) software developed at Ames Research Center uses artificial intelligence and data mining techniques to build system-monitoring knowledge bases from archived or simulated sensor data. This information is then used to detect unusual or anomalous behavior that may indicate an impending system failure. Currently helping analyze data from systems that help fly and maintain the space shuttle and the International Space Station (ISS), the IMS has also been employed by data classes are then used to build a monitoring knowledge base. In real time, IMS performs monitoring functions: determining and displaying the degree of deviation from nominal performance. IMS trend analyses can detect conditions that may indicate a failure or required system maintenance. The development of IMS was motivated by the difficulty of producing detailed diagnostic models of some system components due to complexity or unavailability of design information. Successful applications have ranged from real-time monitoring of aircraft engine and control systems to anomaly detection in space shuttle and ISS data. IMS was used on shuttle missions STS-121, STS-115, and STS-116 to search the Wing Leading Edge Impact Detection System (WLEIDS) data for signs of possible damaging impacts during launch. It independently verified findings of the WLEIDS Mission Evaluation Room (MER) analysts and indicated additional points of interest that were subsequently investigated by the MER team. In support of the Exploration Systems Mission Directorate, IMS is being deployed as an anomaly detection tool on ISS mission control consoles in the Johnson Space Center Mission Operations Directorate. IMS has been trained to detect faults in the ISS Control Moment Gyroscope (CMG) systems. In laboratory tests, it has already detected several minor anomalies in real-time CMG data. When tested on archived data, IMS was able to detect precursors of the CMG1 failure nearly 15 hours in advance of the actual failure event. In the Aeronautics Research Mission Directorate, IMS successfully performed real-time engine health analysis. IMS was able to detect simulated failures and actual engine anomalies in an F/A-18 aircraft during the course of 25 test flights. IMS is also being used in colla
Author
PROJECT MANAGEMENT; LEADING EDGES; KNOWLEDGE BASED SYSTEMS; CONTROL MOMENT GYROSCOPES; DATA SYSTEMS; IMPACT TESTING MACHINES
20090002492 Seldon Technologies, Inc., Windsor, VT, United States
Portable Nanomesh Creates Safer Drinking Water
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 118-11; In English; Original contains color illustrations
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Providing astronauts with clean water is essential to space exploration to ensure the health and well-being of crewmembers away from Earth. For the sake of efficient and safe long-term space travel, NASA constantly seeks to improve the process of filtering and re-using wastewater in closed-loop systems. Because it would be impractical for astronauts to bring months (or years) worth of water with them, reducing the weight and space taken by water storage through recycling and filtering as much water as possible is crucial. Closed-loop systems using nanotechnology allow wastewater to be cleaned and reused while keeping to a minimum the amount of drinking water carried on missions. Current high-speed filtration methods usually require electricity, and methods without electricity usually prove impractical or slow. Known for their superior strength and electrical conductivity, carbon nanotubes measure only a few nanometers in diameter; a nanometer is one billionth of a meter, or roughly one hundred-thousandth the width of a human hair. Nanotubes have improved water filtration by eliminating the need for chemical treatments, significant pressure, and heavy water tanks, which makes the new technology especially appealing for applications where small, efficient, lightweight materials are required, whether on Earth or in space. "NASA will need small volume, effective water purification systems for future long-duration space flight," said Johnson Space Center s Karen Pickering. NASA advances in water filtration with nanotechnology are now also protecting human health in the most remote areas of Earth.
Author
WATER TREATMENT; SPACE EXPLORATION; POTABLE WATER; NANOTECHNOLOGY; FILTRATION; ASTRONAUTS
20090002493 Horton's Orthotic Lab., Inc., Little Rock, AR, United States
Lockable Knee Brace Speeds Rehabilitation
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 54-5; In English; Original contains color illustrations
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Marshall Space Flight Center develops key transportation and propulsion technologies for the Space Agency. The Center manages propulsion hardware and technologies of the space shuttle, develops the next generation of space transportation and propulsion systems, oversees science and hardware development for the International Space Station, manages projects and studies that will help pave the way back to the Moon, and handles a variety of associated scientific endeavors to benefit space exploration and improve life here on Earth. It is a large and diversified center, and home to a great wealth of design skill. Some of the same mechanical design skill that made its way into the plans for rocket engines and advanced propulsion at this Alabama-based NASA center also worked its way into the design of an orthotic knee joint that is changing the lives of people with weakened quadriceps.
Author
MECHANICAL ENGINEERING; HARDWARE; SUPPORTS; KNEE (ANATOMY)
20090002494 SpeedoUSA, New York, NY, United States
Space Age Swimsuit Reduces Drag, Breaks Records
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 96-9; In English; Original contains color illustrations
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A space shuttle and a competitive swimmer have a lot more in common than people might realize: Among other forces, both have to contend with the slowing influence of drag. NASA s Aeronautics Research Mission Directorate focuses primarily on improving flight efficiency and generally on fluid dynamics, especially the forces of pressure and viscous drag, which are the same for bodies moving through air as for bodies moving through water. Viscous drag is the force of friction that slows down a moving object through a substance, like air or water. NASA uses wind tunnels for fluid dynamics research, studying the forces of friction in gasses and liquids. Pressure forces, according to Langley Research Center s Stephen Wilkinson, dictate the optimal shape and performance of an airplane or other aero/hydro-dynamic body. In both high-speed flight and swimming, says Wilkinson, a thin boundary layer of reduced velocity fluid surrounds the moving body; this layer is about 2 centimeters thick for a swimmer.
Author
AERODYNAMICS; DRAG; PRESSURE DRAG; SWIMMING; GARMENTS; FLUID DYNAMICS; VISCOUS DRAG
20090002495 LMS International, Leuven, Belgium
Engineering Models Ease and Speed Prototyping
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 74-7; In English; Original contains color illustrations
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NASA astronauts plan to return to the Moon as early as 2015 and establish a lunar base, from which 6-month flights to Mars would be launched by 2030. Essential to this plan is the Ares launch vehicle, NASA s next-generation spacecraft that will, in various iterations, be responsible for transporting all equipment and personnel to the Moon, Mars, and beyond for the foreseeable future. The Ares launch vehicle is powered by the J-2X propulsion system, with what will be the world s largest rocket nozzles. One of the conditions that engineers carefully consider in designing rocket nozzles particularly large ones is called separation phenomenon, which occurs when outside ambient air is sucked into the nozzle rim by the relatively low pressures of rapidly expanding exhaust gasses. This separation of exhaust gasses from the side-wall imparts large asymmetric transverse loads on the nozzle, deforming the shape and thus perturbing exhaust flow to cause even greater separation. The resulting interaction can potentially crack the nozzle or break actuator arms that control thrust direction. Side-wall loads are extremely difficult to measure directly, and, until now, techniques were not available for accurately predicting the magnitude and frequency of the loads. NASA researchers studied separation phenomenon in scale-model rocket nozzles, seeking to use measured vibration on these nozzle replicas to calculate the unknown force causing the vibrations. Key to this approach was the creation of a computer model accurately representing the nozzle as well as the test cell.
Author
COMPUTERIZED SIMULATION; TRANSVERSE LOADS; PROTOTYPES; ENGINEERS; SCALE MODELS; LUNAR BASES; EXHAUST GASES; ROCKET NOZZLES
20090002496 Optimal Solutions Software, LLC, Idaho Falls, ID, United States
Software Performs Complex Design Analysis
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 76-7; In English; Original contains color illustrations
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Designers use computational fluid dynamics (CFD) to gain greater understanding of the fluid flow phenomena involved in components being designed. They also use finite element analysis (FEA) as a tool to help gain greater understanding of the structural response of components to loads, stresses and strains, and the prediction of failure modes. Automated CFD and FEA engineering design has centered on shape optimization, which has been hindered by two major problems: 1) inadequate shape parameterization algorithms, and 2) inadequate algorithms for CFD and FEA grid modification. Working with software engineers at Stennis Space Center, a NASA commercial partner, Optimal Solutions Software LLC, was able to utilize its revolutionary, one-of-a-kind arbitrary shape deformation (ASD) capability-a major advancement in solving these two aforementioned problems-to optimize the shapes of complex pipe components that transport highly sensitive fluids. The ASD technology solves the problem of inadequate shape parameterization algorithms by allowing the CFD designers to freely create their own shape parameters, therefore eliminating the restriction of only being able to use the computer-aided design (CAD) parameters. The problem of inadequate algorithms for CFD grid modification is solved by the fact that the new software performs a smooth volumetric deformation. This eliminates the extremely costly process of having to remesh the grid for every shape change desired. The program can perform a design change in a markedly reduced amount of time, a process that would traditionally involve the designer returning to the CAD model to reshape and then remesh the shapes, something that has been known to take hours, days-even weeks or months-depending upon the size of the model.
Author
COMPUTATIONAL FLUID DYNAMICS; COMPUTER AIDED DESIGN; DESIGN ANALYSIS; SOFTWARE ENGINEERING; STRUCTURAL DESIGN; SHAPE OPTIMIZATION; FINITE ELEMENT METHOD; FLUID FLOW
20090002497 Endpoint Environmental, LLC, San Francisco, CA, United States
Computer Model Locates Environmental Hazards
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 112-11; In English; Original contains color illustrations
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Catherine Huybrechts Burton founded San Francisco-based Endpoint Environmental (2E) LLC in 2005 while she was a student intern and project manager at Ames Research Center with NASA's DEVELOP program. The 2E team created the Tire Identification from Reflectance model, which algorithmically processes satellite images using turnkey technology to retain only the darkest parts of an image. This model allows 2E to locate piles of rubber tires, which often are stockpiled illegally and cause hazardous environmental conditions and fires.
Author
COMPUTERIZED SIMULATION; HAZARDS; EARTH ENVIRONMENT; SATELLITE IMAGERY; MODELS
20090002498 Hasselblad (Victor) A.B., Goteborg, Sweden
Historic Partnership Captures Our Imagination
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 100-10; In English; Original contains color illustrations
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Avail Online: http://hdl.handle.net/2060/20090002498
Victor Hasselblad AB, of Gothenburg, Sweden, has enjoyed a long-lived collaboration with NASA, especially Johnson Space Center. For over four decades, Hasselblad has supplied camera equipment to the NASA Space Program, and Hasselblad cameras still take on average between 1,500 and 2,000 photographs on each space shuttle mission. Collaboration with NASA has allowed a very small company to achieve worldwide recognition-Hassleblad's operations now include centers in Parsippany, New Jersey; and Redmond, Washington; as well as France and Denmark-and consumer camera models have featured improvements resulting from refinements for the space models.
Author
CAMERAS; SPACE SHUTTLE MISSIONS; NASA SPACE PROGRAMS; AEROSPACE SCIENCES
20090002499 Morgan Research Corp., Huntsville, AL, United States
Outboard Motor Maximizes Power and Dependability
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 104-10; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002499
Developed by Jonathan Lee, a structural materials engineer at Marshall Space Flight Center, and PoShou Chen, a scientist with Huntsville, Alabama-based Morgan Research Corporation, MSFC-398 is a high-strength aluminum alloy able to operate at high temperatures. MSFC-398 was licensed for marine applications by Bombardier Recreational Products Inc., and is now found in the complete line of Evinrude E-TEC outboard motors, a line of two-stroke motors that maintain the power and dependability of a two-stroke with the refinement of a four-stroke.
Author
HIGH STRENGTH ALLOYS; MARINE TECHNOLOGY; HEAT RESISTANT ALLOYS; MOTORS; STRUCTURAL ENGINEERING
20090002500 Knowledge-Based Systems, Inc., College Station, TX, United States
Software Schedules Missions, Aids Project Management
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 128-12; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002500
NASA missions require advanced planning, scheduling, and management, and the Space Agency has worked extensively to develop the programs and software suites necessary to facilitate these complex missions. These enormously intricate undertakings have hundreds of active components that need constant management and monitoring. It is no surprise, then, that the software developed for these tasks is often applicable in other high-stress, complex environments, like in government or industrial settings. NASA work over the past few years has resulted in a handful of new scheduling, knowledge-management, and research tools developed under contract with one of NASA s partners. These tools have the unique responsibility of supporting NASA missions, but they are also finding uses outside of the Space Program.
Author
SPACE PROGRAMS; PROJECT MANAGEMENT; SCHEDULES; NASA PROGRAMS; COMPUTER PROGRAMS
20090002501 Advanced Coatings International, Akron, OH, United States
Water-Based Coating Simplifies Circuit Board Manufacturing
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 12; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002501
The Structures and Materials Division at Glenn Research Center is devoted to developing advanced, high-temperature materials and processes for future aerospace propulsion and power generation systems. The Polymers Branch falls under this division, and it is involved in the development of high-performance materials, including polymers for high-temperature polymer matrix composites; nanocomposites for both high- and low-temperature applications; durable aerogels; purification and functionalization of carbon nanotubes and their use in composites; computational modeling of materials and biological systems and processes; and developing polymer-derived molecular sensors. Essentially, this branch creates high-performance materials to reduce the weight and boost performance of components for space missions and aircraft engine components. Under the leadership of chemical engineer, Dr. Michael Meador, the Polymers Branch boasts world-class laboratories, composite manufacturing facilities, testing stations, and some of the best scientists in the field.
Author
COATING; CIRCUIT BOARDS; AEROGELS; NANOCOMPOSITES; HIGH TEMPERATURE
20090002502 Quantum Devices, Inc., Barneveld, WI, United States
LED Device Illuminates New Path to Healing
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 50-5; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002502
Among NASA s research goals is increased understanding of factors affecting plant growth, including the effects of microgravity. Impeding such studies, traditional light sources used to grow plants on Earth are difficult to adapt to space flight, as they require considerable amounts of power and produce relatively large amounts of heat. As such, an optimized experimental system requires much less energy and reduces temperature variance without negatively affecting plant growth results. Ronald W. Ignatius, founder and chairman of the board at Quantum Devices Inc. (QDI), of Barneveld, Wisconsin, proposed using light-emitting diodes (LEDs) as the photon source for plant growth experiments in space. This proposition was made at a meeting held by the Wisconsin Center for Space Automation and Robotics, a NASA-sponsored research center that facilitates the commercialization of robotics, automation, and other advanced technologies. The Wisconsin group teamed with QDI to determine whether an LED system could provide the necessary wavelengths and intensities for photosynthesis, and the resultant system proved successful. The center then produced the Astroculture3, a plant growth chamber that successfully incorporated this LED light source, which has now flown on several space shuttle missions. NASA subsequently identified another need that could be addressed with the use of LEDs: astronaut health. A central concern in astronaut health is maintaining healthy growth of cells, including preventing bone and muscle loss and boosting the body s ability to heal wounds all adversely affected by prolonged weightlessness. Thus, having determined that LEDs can be used to grow plants in space, NASA decided to investigate whether LEDs might be used for photobiomodulation therapy (PBMT).
Author
LIGHT EMITTING DIODES; PHOTOSYNTHESIS; VEGETATION GROWTH; THERAPY; BONE DEMINERALIZATION; MUSCLES; NASA PROGRAMS; ASTRONAUTS
20090002503 Deep Ocean Engineering, Inc., San Leandro, CA, United States
Robots Explore the Farthest Reaches of Earth and Space
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 116-11; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002503
"We were the first that ever burst/Into that silent sea," the title character recounts in Samuel Taylor Coleridge s opus Rime of the Ancient Mariner. This famous couplet is equally applicable to undersea exploration today as surface voyages then, and has recently been applied to space travel in the title of a chronicle of the early years of human space flight ("Into That Silent Sea: Trailblazers of the Space Era, 1961-1965"), companion to the +n the Shadow of the Moon book and movie. The parallel is certainly fitting, considering both fields explore unknown, harsh, and tantalizingly inhospitable environments. For starters, exploring the Briny Deep and the Final Frontier requires special vehicles, and the most economical and safest means for each employ remotely operated vehicles (ROVs). ROVs have proven the tool of choice for exploring remote locations, allowing scientists to explore the deepest part of the sea and the furthest reaches of the solar system with the least weight penalty, the most flexibility and specialization of design, and without the need to provide for sustaining human life, or the risk of jeopardizing that life. Most NASA probes, including the historic Voyager I and II spacecraft and especially the Mars rovers, Spirit and Opportunity, feature remote operation, but new missions and new planetary environments will demand new capabilities from the robotic explorers of the future. NASA has an acute interest in the development of specialized ROVs, as new lessons learned on Earth can be applied to new environments and increasingly complex missions in the future of space exploration.
Author
ROBOTS; ROVING VEHICLES; SPACE EXPLORATION; PLANETARY ENVIRONMENTS; MARINER SPACECRAFT
20090002504 BioServe Space Technologies, United States; Agrihouse Inc, Berthoud, CO, United States
Experiments Advance Gardening at Home and in Space
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 94-9; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002504
Aeroponics, the process of growing plants suspended in air without soil or media, provides clean, efficient, and rapid food production. Crops can be planted and harvested year-round without interruption, and without contamination from soil, pesticides, and residue. Aeroponic systems also reduce water usage by 98 percent, fertilizer usage by 60 percent, and eliminate pesticide usage altogether. Plants grown in aeroponic systems have been shown to absorb more minerals and vitamins, making the plants healthier and potentially more nutritious. The suspended system also has other advantages. Since the growing environment can be kept clean and sterile, the chances of spreading plant diseases and infections commonly found in soil and other growing media are greatly reduced. Also, seedlings do not stretch or wilt while their roots are forming, and once the roots are developed, the plants can be easily moved into any type of growing media without the risk of transplant shock. Lastly, plants tend to grow faster in a regulated aeroponic environment, and the subsequent ease of transplant to a natural medium means a higher annual crop yield. For example, tomatoes are traditionally started in pots and transplanted to the ground at least 28 days later; growers using an aeroponic system can transplant them just 10 days after starting the plants in the growing chamber. This accelerated cycle produces six tomato crops per year, rather than the traditional one to two crop cycles. These benefits, along with the great reduction in weight by eliminating soil and much of the water required for plant growth, illustrate why this technique has found such enthusiastic support from NASA. Successful long-term missions into deep space will require crews to grow some of their own food during flight. Aeroponic crops are also a potential source of fresh oxygen and clean drinking water, and every ounce of food produced and water conserved aboard a spacecraft reduces payload weight, decreasing launch costs and freeing room for other cargo.
Author
VEGETATION GROWTH; TRANSPLANTATION; FARM CROPS; INFECTIOUS DISEASES; PLANT DISEASES; VITAMINS; TOMATOES
20090002505 Sensics, Inc., Baltimore, MD, United States
Virtual Reality System Offers a Wide Perspective
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 134-13; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002505
Robot Systems Technology Branch engineers at Johnson Space Center created the remotely controlled Robonaut for use as an additional "set of hands" in extravehicular activities (EVAs) and to allow exploration of environments that would be too dangerous or difficult for humans. One of the problems Robonaut developers encountered was that the robot s interface offered an extremely limited field of vision. Johnson robotics engineer, Darby Magruder, explained that the 40-degree field-of-view (FOV) in initial robotic prototypes provided very narrow tunnel vision, which posed difficulties for Robonaut operators trying to see the robot s surroundings. Because of the narrow FOV, NASA decided to reach out to the private sector for assistance. In addition to a wider FOV, NASA also desired higher resolution in a head-mounted display (HMD) with the added ability to capture and display video.
Author
VIRTUAL REALITY; EXTRAVEHICULAR ACTIVITY; ROBOTICS; PERIPHERAL VISION; ROBOTS; FIELD OF VIEW
20090002506 Carnegie-Mellon Univ., Pittsburgh, PA, United States
Mars Cameras Make Panoramic Photography a Snap
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 92-9; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002506
If you wish to explore a Martian landscape without leaving your armchair, a few simple clicks around the NASA Web site will lead you to panoramic photographs taken from the Mars Exploration Rovers, Spirit and Opportunity. Many of the technologies that enable this spectacular Mars photography have also inspired advancements in photography here on Earth, including the panoramic camera (Pancam) and its housing assembly, designed by the Jet Propulsion Laboratory and Cornell University for the Mars missions. Mounted atop each rover, the Pancam mast assembly (PMA) can tilt a full 180 degrees and swivel 360 degrees, allowing for a complete, highly detailed view of the Martian landscape. The rover Pancams take small, 1 megapixel (1 million pixel) digital photographs, which are stitched together into large panoramas that sometimes measure 4 by 24 megapixels. The Pancam software performs some image correction and stitching after the photographs are transmitted back to Earth. Different lens filters and a spectrometer also assist scientists in their analyses of infrared radiation from the objects in the photographs. These photographs from Mars spurred developers to begin thinking in terms of larger and higher quality images: super-sized digital pictures, or gigapixels, which are images composed of 1 billion or more pixels. Gigapixel images are more than 200 times the size captured by today s standard 4 megapixel digital camera. Although originally created for the Mars missions, the detail provided by these large photographs allows for many purposes, not all of which are limited to extraterrestrial photography.
Author
DIGITAL CAMERAS; PHOTOGRAPHY; PANORAMIC CAMERAS; MARS EXPLORATION; LENSES; ATTITUDE (INCLINATION); PIXELS; MARS PHOTOGRAPHS
20090002507 Interactive Pictures Corp., Oak Ridge, TN, United States
Immersive Photography Renders 360 degree Views
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 98-9; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002507
An SBIR contract through Langley Research Center helped Interactive Pictures Corporation, of Knoxville, Tennessee, create an innovative imaging technology. This technology is a video imaging process that allows real-time control of live video data and can provide users with interactive, panoramic 360 views. The camera system can see in multiple directions, provide up to four simultaneous views, each with its own tilt, rotation, and magnification, yet it has no moving parts, is noiseless, and can respond faster than the human eye. In addition, it eliminates the distortion caused by a fisheye lens, and provides a clear, flat view of each perspective.
Author
IMAGING TECHNIQUES; PHOTOGRAPHY; PANORAMIC CAMERAS; MAGNIFICATION
20090002508 3D PLUS USA Inc., McKinney, TX, United States
Intelligent Memory Module Overcomes Harsh Environments
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 142-14; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002508
Solar cells, integrated circuits, and sensors are essential to manned and unmanned space flight and exploration, but such systems are highly susceptible to damage from radiation. Especially problematic, the Van Allen radiation belts encircle Earth in concentric radioactive tori at distances from about 6,300 to 38,000 km, though the inner radiation belt can dip as low as 700 km, posing a severe hazard to craft and humans leaving Earth s atmosphere. To avoid this radiation, the International Space Station and space shuttles orbit at altitudes between 275 and 460 km, below the belts range, and Apollo astronauts skirted the edge of the belts to minimize exposure, passing swiftly through thinner sections of the belts and thereby avoiding significant side effects. This radiation can, however, prove detrimental to improperly protected electronics on satellites that spend the majority of their service life in the harsh environment of the belts. Compact, high-performance electronics that can withstand extreme environmental and radiation stress are thus critical to future space missions. Increasing miniaturization of electronics addresses the need for lighter weight in launch payloads, as launch costs put weight at a premium. Likewise, improved memory technologies have reduced size, cost, mass, power demand, and system complexity, and improved high-bandwidth communication to meet the data volume needs of the next-generation high-resolution sensors. This very miniaturization, however, has exacerbated system susceptibility to radiation, as the charge of ions may meet or exceed that of circuitry, overwhelming the circuit and disrupting operation of a satellite. The Hubble Space Telescope, for example, must turn off its sensors when passing through intense radiation to maintain reliable operation. To address the need for improved data quality, additional capacity for raw and processed data, ever-increasing resolution, and radiation tolerance, NASA spurred the development of the Radiation Tolerant Intelligent Memory Stack (RTIMS).
Author
ENVIRONMENT EFFECTS; INTEGRATED CIRCUITS; SOLAR CELLS; MANNED SPACE FLIGHT; INNER RADIATION BELT; HIGH RESOLUTION
20090002509 Nanotailor, Inc., Austin, TX, United States
NASA Innovation Builds Better Nanotubes
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 158-15; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002509
Nanotailor Inc., based in Austin, Texas, licensed Goddard Space Flight Center's unique single-walled carbon nanotube (SWCNT) fabrication process with plans to make high-quality, low-cost SWCNTs available commercially. Carbon nanotubes are being used in a wide variety of applications, and NASA's improved production method will increase their applicability in medicine, microelectronics, advanced materials, and molecular containment. Nanotailor built and tested a prototype based on Goddard's process, and is using this technique to lower the cost and improve the integrity of nanotubes, offering a better product for use in biomaterials, advanced materials, space exploration, highway and building construction, and many other applications.
Author
CARBON NANOTUBES; FABRICATION; COMPOSITE MATERIALS; NANOTECHNOLOGY
20090002510 Martek Biosciences Corp., Columbia, MD, United States
Space Research Fortifies Nutrition Worldwide
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 106-10; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002510
NASA's Controlled Ecological Life Support Systems program attempted to address basic needs of crews, meet stringent payload and power usage restrictions, and minimize space occupancy, by developing living, regenerative ecosystems that would take care of themselves and their inhabitants. An experiment from this program evolved into one of the most widespread NASA spinoffs of all time-a method for manufacturing an algae-based food supplement that provides the nutrients previously only available in breast milk. Martek Biosciences Corporation, in Columbia, Maryland, now manufactures this supplement, and it can be found in over 90 percent of the infant formulas sold in the United States, as well as those sold in over 65 other countries. With such widespread use, the company estimates that over 24 million babies worldwide have consumed its nutritional additives.
Author
CLOSED ECOLOGICAL SYSTEMS; ECOSYSTEMS; NUTRITION; AEROSPACE SCIENCES
20090002511 MRLB International, Inc., River Falls, WI, United States
In-Line Filtration Improves Hygiene and Reduces Expense
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 48-4; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002511
MRLB International Inc., of Fergus Falls, Minnesota, designed the DentaPure waterline purification cartridge using water purification research conducted by Umpqua Research Company, of Myrtle Creek, Oregon, as part of SBIR contracts from Johnson Space Center. Various models now address a variety of needs, and are used in dental offices and dental schools across the country. Currently the only waterline system recognized by the FDA as a medical device which meets all known standards and by the U.S. Environmental Protection Agency (EPA) as an antimicrobial device, DentaPure has also been utilized by the U.S. Air Force.
Author
FILTRATION; WATER TREATMENT; ECOSYSTEMS; INTERNATIONAL SPACE STATION
20090002512 MTS Systems Corp., Eden Prairie, MN, United States
NASA Design Strengthens Welds
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 154-15; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002512
Friction Stir Welding (FSW) is a solid-state joining process-a combination of extruding and forging-ideal for use when the original metal characteristics must remain as unchanged as possible. While exploring methods to improve the use of FSW in manufacturing, engineers at Marshall Space Flight Center created technologies to address the method's shortcomings. MTS Systems Corporation, of Eden Prairie, Minnesota, discovered the NASA-developed technology and then signed a co-exclusive license agreement to commercialize Marshall's design for use in high-strength structural alloys. The resulting process offers the added bonuses of being cost-competitive, efficient, and most importantly, versatile.
Author
MANUFACTURING; TECHNOLOGY UTILIZATION; MECHANICAL ENGINEERING; HIGH STRENGTH ALLOYS; FRICTION STIR WELDING
20090002513 Maverick Corp., Blue Ash, OH, United States
Polyimide Boosts High-Temperature Performance
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 156-15; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002513
Maverick Corporation, of Blue Ash, Ohio, licensed DMBZ-15 polyimide technology from Glenn Research Center. This ultrahigh-temperature material provides substantial weight savings and reduced machining costs compared to the same component made with more traditional metallic materials. DMBZ-15 has a wide range of applications from aerospace (aircraft engine and airframe components, space transportation systems, and missiles) to non-aerospace (oil drilling, rolling mill), and is particularly well-suited to use as face sheets with honey cones or thermal protection systems for reusable launch vehicles, which encounter elevated temperatures during launch and re-entry.
Author
HIGH TEMPERATURE; POLYIMIDES; TECHNOLOGY UTILIZATION; REFRACTORY MATERIALS; SPACE TRANSPORTATION SYSTEM
20090002514 Hybrid Technologies, LLC, Amherst, NY, United States
Lithium Battery Power Delivers Electric Vehicles to Market
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 66-6; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002514
Hybrid Technologies Inc., a manufacturer and marketer of lithium-ion battery electric vehicles, based in Las Vegas, Nevada, and with research and manufacturing facilities in Mooresville, North Carolina, entered into a Space Act Agreement with Kennedy Space Center to determine the utility of lithium-powered fleet vehicles. NASA contributed engineering expertise for the car's advanced battery management system and tested a fleet of zero-emission vehicles on the Kennedy campus. Hybrid Technologies now offers a series of purpose-built lithium electric vehicles dubbed the LiV series, aimed at the urban and commuter environments.
Derived from text
LITHIUM BATTERIES; ELECTRIC MOTOR VEHICLES
20090002515 inXitu, Mountain View, CA, United States
Advanced X-Ray Sources Ensure Safe Environments
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 86-8; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002515
Ames Research Center awarded inXitu Inc. (formerly Microwave Power Technology), of Mountain View, California, an SBIR contract to develop a new design of electron optics for forming and focusing electron beams that is applicable to a broad class of vacuum electron devices. This technology offers an inherently rugged and more efficient X-ray source for material analysis; a compact and rugged X-ray source for smaller rovers on future Mars missions; and electron beam sources to reduce undesirable emissions from small, widely distributed pollution sources; and remediation of polluted sites.
Derived from text
ELECTRONIC EQUIPMENT; CARBON NANOTUBES; CATHODES; ELECTRON OPTICS; ELECTRON BEAMS; BEAMFORMING; FOCUSING; ENVIRONMENTAL CONTROL; TECHNOLOGY UTILIZATION
20090002516 Tidewater Sensors LLC, New Port News, VA, United States
Wireless Fluid-Level Measurement System Equips Boat Owners
Spinoff 2008: 50 Years of NASA-Derived Technologies (1958-2008); 2008; pp. 90-9; In English; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002516
While developing a measurement acquisition system to be used to retrofit aging aircraft with vehicle health monitoring capabilities, Langley Research Center developed an innovative wireless fluid-level measurement system. The NASA technology was of interest to Tidewater Sensors LLC, of Newport News, Virginia, because of its many advantages over conventional fuel management systems, including its ability to provide an accurate measurement of volume while a boat is experiencing any rocking motion due to waves or people moving about on the boat. These advantages led the company to license this novel fluid-level measurement system from NASA for marine applications.
Author
FUEL GAGES; MANAGEMENT SYSTEMS; WIRELESS COMMUNICATION; SENSORS; MARINE TECHNOLOGY
20090002548 NASA Dryden Flight Research Center, Edwards, CA, United States
Overview of the LaNCETS Flight Experiment and the CFD Analysis
Cliatt, Larry J., II; Haering, Edward A., Jr.; Bio, Trong; October 07, 2008; In English; Fundamental Aeronautics 2008 Annual Meeting, 7-9 Oct. 2008, Atlanta, GA, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002548
LaCETS baseline flight study include: 29 high-quality nearfield shock structure probings at three Mach numbers; Shocks in exhaust plume measured; ! CFD study of simplified nozzle shows similar plume structures as flight data; ! Phase II flights scheduled for October 2008; and ! US Industry and Academia invited to participate in analysis, review, and assessment of LaNCETS data.
Author
COMPUTATIONAL FLUID DYNAMICS; INDUSTRIES; PLUMES
20090002561 NASA Marshall Space Flight Center, Huntsville, AL, United States
Ares I Crew Launch Vehicle Upper Stage Element Overview
McArthur, J. Craig; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford, CT, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002561
This viewgraph presentation gives an overview of NASA's Ares I Crew Launch Vehicle Upper Stage Element. The topics incluse: 1) What is NASA s Mission?; 2) NASA s Exploration Roadmap What is our time line?; 3) Building on a Foundation of Proven Technologies Launch Vehicle Comparisons; 4) Ares I Upper Stage; 5) Upper Stage Primary Products; 6) Ares I Upper Stage Development Approach; 7) What progress have we made?; 8) Upper Stage Subsystem Highlights; 9) Structural Testing; 10) Common Bulkhead Processing; 11) Stage Installation at Stennis Space Center; 12) Boeing Producibility Team; 13) Upper Stage Low Cost Strategy; 14) Ares I and V Production at Michoud Assembly Facility (MAF); 15) Merged Manufacturing Flow; and 16) Manufacturing and Assembly Weld Tools.
CASI
ARES 1 UPPER STAGE; GENERAL OVERVIEWS; SPACE SHUTTLES; ARES 5 CARGO LAUNCH VEHICLE; FABRICATION
20090002563 McDonnell-Douglas Corp., Saint Louis, MO United States
Reconfiguration control system for an aircraft wing
Wakayama, Sean R., Inventor; November 25, 2008; In English
Contract(s)/Grant(s): NAS1-20275
Patent Info.: August 26, 1997US-Patent-7,455,264; US-Patent-Appl-SN-08/917,480
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002563
Independently deflectable control surfaces are located on the trailing edge of the wing of a blended wing-body aircraft. The reconfiguration control system of the present invention controls the deflection of each control surface to optimize the spanwise lift distribution across the wing for each of several flight conditions, e.g., cruise, pitch maneuver, and high lift at low speed. The control surfaces are deflected and reconfigured to their predetermined optimal positions when the aircraft is in each of the aforementioned flight conditions. With respect to cruise, the reconfiguration control system will maximize the lift to drag ratio and keep the aircraft trimmed at a stable angle of attack. In a pitch maneuver, the control surfaces are deflected to pitch the aircraft and increase lift. Moreover, this increased lift has its spanwise center of pressure shifted inboard relative to its location for cruise. This inboard shifting reduces the increased bending moment about the aircraft's x-axis occasioned by the increased pitch force acting normal to the wing. To optimize high lift at low speed, during take-off and landing for example, the control surfaces are reconfigured to increase the local maximum coefficient of lift at stall-critical spanwise locations while providing pitch trim with control surfaces that are not stall critical.
Official Gazette of the U.S. Patent and Trademark Office
CONTROL SURFACES; TRAILING EDGES; AIRCRAFT CONTROL; BLENDED-WING-BODY CONFIGURATIONS; LIFT DRAG RATIO
20090002564 NASA, Washington, DC United States
Robust, optimal subsonic airfoil shapes
Rai, Man Mohan, Inventor; November 18, 2008; In English
Patent Info.: July 1, 2005US-Patent-7,454,321; US-Patent-Appl-SN-11/173,447
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002564
Method system, and product from application of the method, for design of a subsonic airfoil shape, beginning with an arbitrary initial airfoil shape and incorporating one or more constraints on the airfoil geometric parameters and flow characteristics. The resulting design is robust against variations in airfoil dimensions and local airfoil shape introduced in the airfoil manufacturing process. A perturbation procedure provides a class of airfoil shapes, beginning with an initial airfoil shape.
Official Gazette of the U.S. Patent and Trademark Office
AIRFOILS; PERTURBATION; MANUFACTURING; FLOW CHARACTERISTICS
20090002566 NASA Marshall Space Flight Center, Huntsville, AL, United States
Very Large Space Optics for an Investigation of the Extreme Universe
Adams, James H.; August 25, 2008; In English; 8th Annual Mirror Technology Days in the Government, 25-27 Aug. 2008, Albuquerque, NM, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
This viewgraph presentation describes the utilization of very large space optics to test the extreme universe.
CASI
UNIVERSE; OPTICS; WIDE ANGLE LENSES; IMAGING TECHNIQUES; SPACECRAFT INSTRUMENTS
20090002568 NASA Marshall Space Flight Center, Huntsville, AL, United States
GFSSP Training Course Lectures
Majumdar, Alok K.; August 18, 2008; In English; Thermal and Fluids Analysis Workshop (TFAWS) 2008, 18-22 Aug. 2008, San Jose, CA, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A07, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002568
GFSSP has been extended to model conjugate heat transfer Fluid Solid Network Elements include: a) Fluid nodes and Flow Branches; b) Solid Nodes and Ambient Nodes; c) Conductors connecting Fluid-Solid, Solid-Solid and Solid-Ambient Nodes. Heat Conduction Equations are solved simultaneously with Fluid Conservation Equations for Mass, Momentum, Energy and Equation of State. The extended code was verified by comparing with analytical solution for simple conduction-convection problem The code was applied to model: a) Pressurization of Cryogenic Tank; b) Freezing and Thawing of Metal; c) Chilldown of Cryogenic Transfer Line; d) Boil-off from Cryogenic Tank.
Derived from text
FLUID FLOW; CRYOGENICS; CONDUCTIVE HEAT TRANSFER; EDUCATION; CONSERVATION EQUATIONS; WORKING FLUIDS; EQUATIONS OF STATE
20090002573 United Technologies Corp., East Hartford, CT United States
Ceramic matrix composite turbine engine vane
Shi, Jun, Inventor; Ochs, Stuart S., Inventor; Green, Kevin E., Inventor; Jarmon, David C., Inventor; Sahm, Michael K., Inventor; Prill, Lisa A., Inventor; November 18, 2008; In English
Contract(s)/Grant(s): NAS3-01138
Patent Info.: May 3, 2006US-Patent-7,452,189; US-Patent-Appl-SN-11/417,972
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002573
A vane has an airfoil shell and a spar within the shell. The vane has an outboard shroud at an outboard end of the shell and an inboard platform at an inboard end of the shell. The spar has a first chamber essentially along the suction side and a second chamber along the pressure side opposite the first chamber.
Official Gazette of the U.S. Patent and Trademark Office
AIRFOILS; VANES; CERAMIC MATRIX COMPOSITES; SHROUDS
Additions to the NASA Aeronautics and Space Database as of 01/28/2009
20090002580 NASA Marshall Space Flight Center, Huntsville, AL, United States
8-Meter UV/Optical Space Telescope at L2
Stahl, H. Philip; August 25, 2008; In English; 8th Annual Mirror Technology Days in the Government, 25-27 Aug. 2008, Albuquerque, NM, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002580
The unprecedented mass/volume capability of an Ares V enables the launch of 8 meter class monolithic space telescopes to the Earth-Sun L2 point. NASA MSFC has determined that a 6 to 8 meter class telescope using a massive high-TRL ground observatory class monolithic primary mirror is feasible. Mature, High-TRL design enables early deployment. Science Instruments, Expendables and Limited Life Components can be replace periodically via Spacecraft Autonomous Rendezvous and Docking.
Author
ULTRAVIOLET TELESCOPES; SPACEBORNE TELESCOPES; ARES 5 CARGO LAUNCH VEHICLE; AUTONOMOUS DOCKING; ORBITAL RENDEZVOUS; SOLAR OPTICAL TELESCOPE; SPACECRAFT DOCKING
20090002581 NASA Marshall Space Flight Center, Huntsville, AL, United States
LETS: Lunar Environments Test System
Vaughn, Jason A.; Schneider, Todd; Craven, Paul; Norwood, Joey; August 12, 2008; In English; Lunar Regolith Behavior Workshop, 12-14 Aug. 2008, Houston, TX, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002581
The Environmental Effects Branch (EM50) at the Marshall Space Flight Center has developed a unique capability within the agency, namely the Lunar Environment Test System (LETS). LETS is a cryo-pumped vacuum chamber facility capable of high vacuum (10-7 Torr). LETS is a cylindrical chamber, 30 in. (0.8 m) diameter by 48 in. (1.2 m) long thermally controlled vacuum system. The chamber is equipped with a full array of radiation sources including vacuum ultraviolet, electron, and proton radiation. The unique feature of LETS is that it contains a large lunar simulant bed (18 in. x 40 in. x 6 in.) holding 75 kg of JSC-1a simulant while operating at a vacuum of 10-7 Torr. This facility allows three applications: 1) to study the charging, levitation and migration of dust particles, 2) to simulate the radiation environment on the lunar surface, and 3) to electrically charge the lunar simulant enhancing the attraction and adhesion of dust particles to test articles more closely simulating the lunar surface dust environment. LETS has numerous diagnostic instruments including TREK electrostatic probes, residual gas analyzer (RGA), temperature controlled quartz crystal microbalance (TQCM), and particle imaging velocimeter (PIV). Finally, LETS uses continuous Labview data acquisition for computer monitoring and system control.
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ENVIRONMENTAL TESTS; LUNAR ENVIRONMENT; LUNAR SURFACE; TEST FACILITIES; RESEARCH FACILITIES
20090002582 NASA Marshall Space Flight Center, Huntsville, AL, United States
Similarity Metrics for Closed Loop Dynamic Systems
Whorton, Mark S.; Yang, Lee C.; Bedrossian, Naz; Hall, Robert A.; August 18, 2008; In English; 2008 AIAA Guidance, Navigation and Control Conference, 18-21 Aug. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
To what extent and in what ways can two closed-loop dynamic systems be said to be "similar?" This question arises in a wide range of dynamic systems modeling and control system design applications. For example, bounds on error models are fundamental to the controller optimization with modern control design methods. Metrics such as the structured singular value are direct measures of the degree to which properties such as stability or performance are maintained in the presence of specified uncertainties or variations in the plant model. Similarly, controls-related areas such as system identification, model reduction, and experimental model validation employ measures of similarity between multiple realizations of a dynamic system. Each area has its tools and approaches, with each tool more or less suited for one application or the other. Similarity in the context of closed-loop model validation via flight test is subtly different from error measures in the typical controls oriented application. Whereas similarity in a robust control context relates to plant variation and the attendant affect on stability and performance, in this context similarity metrics are sought that assess the relevance of a dynamic system test for the purpose of validating the stability and performance of a "similar" dynamic system. Similarity in the context of system identification is much more relevant than are robust control analogies in that errors between one dynamic system (the test article) and another (the nominal "design" model) are sought for the purpose of bounding the validity of a model for control design and analysis. Yet system identification typically involves open-loop plant models which are independent of the control system (with the exception of limited developments in closed-loop system identification which is nonetheless focused on obtaining open-loop plant models from closed-loop data). Moreover the objectives of system identification are not the same as a flight test and hence system identification error metrics are not directly relevant. In applications such as launch vehicles where the open loop plant is unstable it is similarity of the closed-loop system dynamics of a flight test that are relevant.
Author
CONTROL SYSTEMS DESIGN; DYNAMIC MODELS; DYNAMIC TESTS; FEEDBACK CONTROL; TRAJECTORY CONTROL
20090002591 NASA Johnson Space Center, Houston, TX, United States
Enhancing Functional Performance using Sensorimotor Adaptability Training Programs
Bloomberg, J. J.; Mulavara, A. P.; Peters, B. T.; Brady, R.; Audas, C.; Ruttley, T. M.; Cohen, H. S.; Feb. 2, 2009; In English; Human Research Program Investigators' Workshop, 2-4 Feb. 2009, League City, TX, United States
Contract(s)/Grant(s): NCC-9-58
Copyright; Avail.: CASI: A01, Hardcopy
During the acute phase of adaptation to novel gravitational environments, sensorimotor disturbances have the potential to disrupt the ability of astronauts to perform functional tasks. The goal of this project is to develop a sensorimotor adaptability (SA) training program designed to facilitate recovery of functional capabilities when astronauts transition to different gravitational environments. The project conducted a series of studies that investigated the efficacy of treadmill training combined with a variety of sensory challenges designed to increase adaptability including alterations in visual flow, body loading, and support surface stability.
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ADAPTATION; EDUCATION; SENSORIMOTOR PERFORMANCE; AEROSPACE MEDICINE
20090002599 NASA Glenn Research Center, Cleveland, OH, United States
CFD Results for an Axisymmetric Isentropic Relaxed Compression Inlet
Hirt, Stefanie M.; Tacina, Kathleen M.; Conners, Timothy R.; Merret, Jason M.; Howe, Donald C.; November 2008; In English; 46th AIAA Aerospace Sciences Meeting, 7-10 Jan. 2008, Reno, NV, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.13.02
Report No.(s): NASA/TM-2008-215416; AIAA Paper-2008-0092; E-16580; Copyright; Avail.: CASI: A03, Hardcopy
The OVERFLOW code was used to calculate the flow field for a family of five relaxed compression inlets, which were part of a screening study to determine a configuration most suited to the application of microscale flow control technology as a replacement for bleed. Comparisons are made to experimental data collected for each of the inlets in the 1- by 1-Foot Supersonic Wind Tunnel at the NASA Glenn Research Center (GRC) to help determine the suitability of computational fluid dynamics (CFD) as a tool for future studies of these inlets with flow control devices. Effects on the wind tunnel results of the struts present in a high subsonic flow region accounted for most of the inconsistency between the results. Based on the level of agreement in the present study, it is expected that CFD can be used as a tool to aid in the design of a study of this class of inlets with flow control.
Author
SUPERSONIC WIND TUNNELS; SUBSONIC FLOW; COMPUTATIONAL FLUID DYNAMICS; FLOW DISTRIBUTION; CONTROL EQUIPMENT
20090002608 NASA Stennis Space Center, Stennis Space Center, MS, United States
Computational Analyses in Support of Sub-scale Diffuser Testing for the A-3 Facility Part 1 Steady Predictions
Allgood, Daniel C.; Graham, Jason S.; Ahuja, Vineet; Hosangadi, Ashvin; [2008]; In English; Original contains color illustrations
Contract(s)/Grant(s): NNS04AB67T; NNX08CA36C
Report No.(s): SSTI-8080-0023; Copyright; Avail.: CASI: A01, Hardcopy
Simulation technology can play an important role in rocket engine test facility design and development by assessing risks, providing analysis of dynamic pressure and thermal loads, identifying failure modes and predicting anomalous behavior of critical systems. Advanced numerical tools assume greater significance in supporting testing and design of high altitude testing facilities and plume induced testing environments of high thrust engines because of the greater inter-dependence and synergy in the functioning of the different sub-systems. This is especially true for facilities such as the proposed A-3 facility at NASA SSC because of a challenging operating envelope linked to variable throttle conditions at relatively low chamber pressures. Facility designs in this case will require a complex network of diffuser ducts, steam ejector trains, fast operating valves, cooling water systems and flow diverters that need to be characterized for steady state performance. In this paper, we will demonstrate with the use of CFD analyses s advanced capability to evaluate supersonic diffuser and steam ejector performance in a sub-scale A-3 facility at NASA Stennis Space Center (SSC) where extensive testing was performed. Furthermore, the focus in this paper relates to modeling of critical sub-systems and components used in facilities such as the A-3 facility. The work here will address deficiencies in empirical models and current CFD analyses that are used for design of supersonic diffusers/turning vanes/ejectors as well as analyses for confined plumes and venting processes. The primary areas that will be addressed are: (1) supersonic diffuser performance including analyses of thermal loads (2) accurate shock capturing in the diffuser duct; (3) effect of turning duct on the performance of the facility (4) prediction of mass flow rates and performance classification for steam ejectors (5) comparisons with test data from sub-scale diffuser testing and assessment of confidence levels in CFD based flowpath modeling of the facility. The analyses tools used here expand on the multi-element unstructured CFD which has been tailored and validated for impingement dynamics of dry plumes, complex valve/feed systems, and high pressure propellant delivery systems used in engine and component test stands at NASA SSC. The analyses performed in the evaluation of the sub-scale diffuser facility explored several important factors that influence modeling and understanding of facility operation such as (a) importance of modeling the facility with Real Gas approximation, (b) approximating the cluster of steam ejector nozzles as a single annular nozzle, (c) existence of mixed subsonic/supersonic flow downstream of the turning duct, and (d) inadequacy of two-equation turbulence models in predicting the correct pressurization in the turning duct and expansion of the second stage steam ejectors. The procedure used for modeling the facility was as follows: (i) The engine, test cell and first stage ejectors were simulated with an axisymmetric approximation (ii) the turning duct, second stage ejectors and the piping downstream of the second stage ejectors were analyzed with a three-dimensional simulation utilizing a half-plane symmetry approximation. The solution i.e. primitive variables such as pressure, velocity components, temperature and turbulence quantities were passed from the first computational domain and specified as a supersonic boundary condition for the second simulation. (iii) The third domain comprised of the exit diffuser and the region in the vicinity of the facility (primary included to get the correct shock structure at the exit of the facility and entrainment characteristics). The first set of simulations comprising the engine, test cell and first stage ejectors was carried out both as a turbulent real gas calculation as well as a turbulent perfect gas calculation. A comparison for the two cases (Real Turbulent and Perfect gas turbulent) of the Ma Number distribution and temperature distributions are shown in Figures 1 and 2 respectively. The Mach Number distribution shows small yet distinct differences between the two cases such as locations of shocks/shock reflections and a slightly different impingement point on the wall of the diffuser from the expansion at the exit of the nozzle. Similarly the temperature distribution indicates different flow recirculation patterns in the test cell. Both cases capture all the essential flow phenomena such as the shock-boundary layer interaction, plume expansion, expansion of the first stage ejectors, mixing between the engine plume and the first stage ejector flow and pressurization due to the first stage ejectors. The final paper will discuss thermal loads on the walls of the diffuser and cooling mechanisms investigated.
Author
COMPUTATIONAL FLUID DYNAMICS; DIVERTERS; TURBULENCE MODELS; ROCKET ENGINE DESIGN; STATISTICAL TESTS; SHOCK WAVE INTERACTION; PRESSURE DISTRIBUTION; TEST FACILITIES; MASS FLOW RATE; DYNAMIC PRESSURE; ANNULAR NOZZLES
20090002612 NASA Johnson Space Center, Houston, TX, United States
Sensorimotor Adaptations Following Exposure to Ambiguous Inertial Motion Cues
Wood, S. J.; Harm, D. L.; Reschke, M. F.; Rupert, A. H.; Clement, G. R.; February 4 2009; In English; Human Research program Investigators' Workshop, 2-4 Feb. 2009, League City, TX, United States
Contract(s)/Grant(s): NCC9-58
Copyright; Avail.: CASI: A01, Hardcopy
The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. We hypothesize that multi-sensory integration will be adaptively optimized in altered gravity environments based on the dynamics of other sensory information available, with greater changes in otolith-mediated responses in the mid-frequency range where there is a crossover of tilt and translation responses. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation.
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CENTRAL NERVOUS SYSTEM; CUES; SENSORIMOTOR PERFORMANCE; SPATIAL DEPENDENCIES; HUMAN FACTORS ENGINEERING
20090002614 NASA Johnson Space Center, Houston, TX, United States
Biosensors for EVA: Muscle Oxygen and pH During Walking, Running and Simulated Reduced Gravity
Lee, S. M. C.; Ellerby, G.; Scott, P.; Stroud, L.; Norcross, J.; Pesholov, B.; Zou, F.; Gernhardt, M.; Soller, B.; [2009]; In English
Copyright; Avail.: CASI: A01, Hardcopy
During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO2 on the leg during cycling. Our NSBRI-funded project is looking to extend this methodology to examine activities which more appropriately represent EVA activities, such as walking and running and to better understand factors that determine the metabolic cost of exercise in both normal and lunar gravity. Our 4 year project specifically addresses risk: ExMC 4.18: Lack of adequate biomedical monitoring capability for Constellation EVA Suits and EPSP risk: Risk of compromised EVA performance and crew health due to inadequate EVA suit systems.
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BIOINSTRUMENTATION; EXTRAVEHICULAR ACTIVITY; OXYGEN CONSUMPTION; SPACE SUITS; METABOLISM; PHYSIOLOGY; MEASURING INSTRUMENTS
20090002616 NASA Johnson Space Center, Houston, TX, United States
Diving in Space
Gernhardt, Michael L.; December 18, 2008; In English; Haldane International Symposium 2008: The Future of Diving: 100 Years of Haldane and Beyond, 18-19 Dec. 2008, Trondheim, Norway; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002616
This viewgraph presentation reviews NASA's extravehicular activity (EVA) procedures and the technological and biomedical issues surrounding EVA.
CASI
EXTRAVEHICULAR ACTIVITY; NASA SPACE PROGRAMS; AEROSPACE MEDICINE; TECHNOLOGY UTILIZATION; PORTABLE LIFE SUPPORT SYSTEMS; MANNED SPACE FLIGHT
20090002632 Regenetech, Inc., Sugar Land, TX United States
Three-dimensional cell to tissue development process
Goodwin, Thomas J., Inventor; Parker, Clayton R., Inventor; November 25, 2008; In English
Patent Info.: June 29, 2005US-Patent-7,456,019; US-Patent-Appl-SN-11/169,385
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002632
An improved three-dimensional cell to tissue development process using a specific time varying electromagnetic force, pulsed, square wave, with minimum fluid shear stress, freedom for 3-dimensional spatial orientation of the suspended particles and localization of particles with differing or similar sedimentation properties in a similar spatial region.
Official Gazette of the U.S. Patent and Trademark Office
SHEAR STRESS; SQUARE WAVES; ATTITUDE (INCLINATION); POSITION (LOCATION); SEDIMENTS
20090002641 California Inst. of Tech., Pasadena, CA United States
Multiple internal seal ring micro-electro-mechanical system vacuum packaging method
Hayworth, Ken J., Inventor; Yee, Karl Y., Inventor; Shcheglov, Kirill V., Inventor; Bae, Youngsam, Inventor; Wiberg, Dean V., Inventor; Challoner, A. Dorian, Inventor; Peay, Chris S., Inventor; July 8, 2008; In English
Patent Info.: September 5, 2007US-Patent-7,396,478; US-Patent-Appl-SN-11/850,458
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002641
A Multiple Internal Seal Ring (MISR) Micro-Electro-Mechanical System (MEMS) vacuum packaging method that hermetically seals MEMS devices using MISR. The method bonds a capping plate having metal seal rings to a base plate having metal seal rings by wafer bonding the capping plate wafer to the base plate wafer. Bulk electrodes may be used to provide conductive paths between the seal rings on the base plate and the capping plate. All seals are made using only metal-to-metal seal rings deposited on the polished surfaces of the base plate and capping plate wafers. However, multiple electrical feed-through metal traces are provided by fabricating via holes through the capping plate for electrical connection from the outside of the package through the via-holes to the inside of the package. Each metal seal ring serves the dual purposes of hermetic sealing and providing the electrical feed-through metal trace.
Official Gazette of the U.S. Patent and Trademark Office
MICROELECTROMECHANICAL SYSTEMS; HERMETIC SEALS; BONDING; VACUUM; SEALING; PACKAGING
20090002644 NASA, Washington, DC United States
Downlink data multiplexer
Holland, S. Douglas, Inventor; Steele, Glen F., Inventor; Romero, Denise M., Inventor; Koudelka, Robert David, Inventor; July 8, 2008; In English
Patent Info.: May 23, 2003US-Patent-7,397,774; US-Patent-Appl-SN-10/446,283
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002644
A data multiplexer that accommodates both industry standard CCSDS data packets and bits streams and standard IEEE 1394 data is described. The multiplexer provides a statistical allotment of bandwidth to the channels in turn, preferably four, but expandable in increments of four up to sixteen. A microcontroller determines bandwidth requested by the plurality of channels, as well as the bandwidth available, and meters out the available bandwidth on a statistical basis employing flow control to the input channels.
Official Gazette of the U.S. Patent and Trademark Office
DOWNLINKING; MULTIPLEXING; DATA FLOW ANALYSIS
20090002649 NASA, Washington, DC United States
Apparatus and method for packaging and integrating microphotonic devices
Nguyen, Hung, Inventor; July 8, 2008; In English
Patent Info.: July 13, 2005US-Patent-7,397,978; US-Patent-Appl-SN-11/180,990
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002649
An apparatus is disclosed that includes a carrier structure and an optical coupling arrangement. The carrier structure is made of a silicon material and allows for the packaging and integrating of microphotonic devices onto a single chip. The optical coupling mechanism enables laser light to be coupled into and out of a microphotonic resonant disk integrated on the carrier. The carrier provides first, second and third cavities that are dimensioned so as to accommodate the insertion and snug fitting of the microphotonic resonant disk and first and second prisms that are implemented by the optical coupling arrangement to accommodate the laser coupling.
Official Gazette of the U.S. Patent and Trademark Office
OPTICAL COUPLING; CHIPS; PHOTONICS; LIGHT BEAMS; PACKAGING; LASER OUTPUTS; PRISMS
20090002651 Children's Hospital of Los Angeles, Los Angeles, CA United States
Assessing blood brain barrier dynamics or identifying or measuring selected substances, including ethanol or toxins, in a subject by analyzing Raman spectrum signals
Lambert, James L., Inventor; Borchert, Mark S., Inventor; July 8, 2008; In English
Patent Info.: March 25, 2003US-Patent-7,398,119; US-Patent-Appl-SN-10/396,035
No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002651
A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier.Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam at a selected wavelength (e.g., at a wavelength of about 400 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum. In certain embodiments, the detecting step may be followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level and/or brain level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing methods are also disclosed.
Official Gazette of the U.S. Patent and Trademark Office
BLOOD-BRAIN BARRIER; RAMAN SPECTRA; ETHYL ALCOHOL; TOXINS AND ANTITOXINS; CEREBROSPINAL FLUID; DETECTION
20090002654 NASA, Washington, DC United States
Large area plasma source
Foster, John, Inventor; Patterson, Michael, Inventor; July 15, 2008; In English
Patent Info.: July 19, 2004US-Patent-7,400,096; US-Patent-Appl-SN-10/894,225
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002654
An all permanent magnet Electron Cyclotron Resonance, large diameter (e.g., 40 cm) plasma source suitable for ion/plasma processing or electric propulsion, is capable of producing uniform ion current densities at its exit plane at very low power (e.g., below 200 W), and is electrodeless to avoid sputtering or contamination issues. Microwave input power is efficiently coupled with an ionizing gas without using a dielectric microwave window and without developing a throat plasma by providing a ferromagnetic cylindrical chamber wall with a conical end narrowing to an axial entrance hole for microwaves supplied on-axis from an open-ended waveguide. Permanent magnet rings are attached inside the wall with alternating polarities against the wall. An entrance magnet ring surrounding the entrance hole has a ferromagnetic pole piece that extends into the chamber from the entrance hole to a continuing second face that extends radially across an inner pole of the entrance magnet ring.
Official Gazette of the U.S. Patent and Trademark Office
ELECTRON CYCLOTRON RESONANCE; ION CURRENTS; PLASMA PROPULSION; CURRENT DENSITY; FERROMAGNETIC MATERIALS; PERMANENT MAGNETS
20090002656 Ophir Corp., Littleton, CO United States
Optical air data systems and methods
Caldwell, Loren M., Inventor; O'Brien, Martin J., Inventor; Weimer, Carl S., Inventor; Nelson, Loren D., Inventor; July 15, 2008; In English
Contract(s)/Grant(s): NAS4-0243
Patent Info.: April 11, 2005US-Patent-7,400,385; US-Patent-Appl-SN-11/103,020
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002656
Systems and methods for sensing air outside a moving aircraft are presented. In one embodiment, a system includes a laser for generating laser energy. The system also includes one or more transceivers for projecting the laser energy as laser radiation to the air. Subsequently, each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines one or more air parameters based on the scattered laser radiation. Such air parameters may include air speed, air pressure, air temperature and aircraft orientation angle, such as yaw, angle of attack and sideslip.
Official Gazette of the U.S. Patent and Trademark Office
AIRSPEED; ATMOSPHERIC PRESSURE; TRANSMITTER RECEIVERS; DETECTION; GAS PRESSURE; ANGLES (GEOMETRY)
20090002657 NASA, Washington, DC United States
Image edge extraction via fuzzy reasoning
Dominguez, Jesus A., Inventor; Klinko, Steve, Inventor; July 15, 2008; In English
Patent Info.: February 19, 2004US-Patent-7,400,766; US-Patent-Appl-SN-10/783,295
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002657
A computer-based technique for detecting edges in gray level digital images employs fuzzy reasoning to analyze whether each pixel in an image is likely on an edge. The image is analyzed on a pixel-by-pixel basis by analyzing gradient levels of pixels in a square window surrounding the pixel being analyzed. An edge path passing through the pixel having the greatest intensity gradient is used as input to a fuzzy membership function, which employs fuzzy singletons and inference rules to assigns a new gray level value to the pixel that is related to the pixel's edginess degree.
Official Gazette of the U.S. Patent and Trademark Office
EDGES; EXTRACTION; COMPUTER TECHNIQUES; DETECTION; FUZZY SYSTEMS; GRADIENTS
20090002658 NASA, Washington, DC United States
Sensing/actuating materials made from carbon nanotube polymer composites and methods for making same
Ounaies, Zoubeida, Inventor; Park, Cheol, Inventor; Harrison, Joycelyn S., Inventor; Holloway, Nancy M., Inventor; Draughon, Gregory K., Inventor; July 22, 2008; In English
Patent Info.: March 3, 2005US-Patent-7,402,264; US-Patent-Appl-SN-11/076,460
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002658
An electroactive sensing or actuating material comprises a composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation of the composite when such composite is affected by an external stimulus. In another embodiment, the composite comprises a third component of micro-sized to nano-sized particles of an electroactive ceramic that is also incorporated in the polymer matrix. The method for making the three-phase composite comprises either incorporating the carbon nanotubes in the polymer matrix before incorporation of the particles of ceramic or mixing the carbon nanotubes and particles of ceramic together in a solution before incorporation in the polymer matrix.
Official Gazette of the U.S. Patent and Trademark Office
COMPOSITE MATERIALS; CARBON NANOTUBES; CERAMICS; DETECTION
20090002659 Boeing Co., Chicago, IL United States
Method of producing an inertial sensor
Shcheglov, Kirill V., Inventor; Challoner, A. Dorian, Inventor; July 22, 2008; In English
Patent Info.: March 9, 2006US-Patent-7,401,397; US-Patent-Appl-SN-11/371,596
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002659
The present invention discloses an inertial sensor comprising a planar mechanical resonator with embedded sensing and actuation for substantially in-plane vibration and having a central rigid support for the resonator. At least one excitation or torquer electrode is disposed within an interior of the resonator to excite in-plane vibration of the resonator and at least one sensing or pickoff electrode is disposed within the interior of the resonator for sensing the motion of the excited resonator. In one embodiment, the planar resonator includes a plurality of slots in an annular pattern; in another embodiment, the planar mechanical resonator comprises four masses; each embodiment having a simple degenerate pair of in-plane vibration modes.
Official Gazette of the U.S. Patent and Trademark Office
DETECTION; RESONATORS; GYROSCOPES; MEASURING INSTRUMENTS
20090002660 California Inst. of Tech., Pasadena, CA United States
GaN-based sensor nodes for in situ detection of gases
Moon, Jeong-Sun, Inventor; Prokopuk, Nicholas, Inventor; Son, Kyung-Ah, Inventor; July 22, 2008; In English
Patent Info.: May 11, 2005US-Patent-7,403,113; US-Patent-Appl-SN-11/128,110
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002660
A system for detecting chemical/biological substances and a detection method. The system comprises a plurality of sensing units or nodes and a radiofrequency link. Each unit has several sensors with different sensing curves. Each sensor is able to transmit information related to the sensed substance on a specific frequency. The sensors preferably comprise AlGaN/GaN high electron mobility transistors.
Official Gazette of the U.S. Patent and Trademark Office
ALUMINUM NITRIDES; DETECTION; BIOCHEMISTRY; GALLIUM NITRIDES
20090002661 Accudyne Systems, Inc., Newark, DE United States
Tape placement head for applying thermoplastic tape to an object
Cope, Ralph D., Inventor; Funck, Steve B., Inventor; Gruber, Mark B., Inventor; Lamontia, Mark A., Inventor; Johnson, Anthony D., Inventor; July 29, 2008; In English
Patent Info.: October 10, 2006US-Patent-7,404,868; US-Patent-Appl-SN-11/548,002
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002661
A tape placement head for applying thermoplastic tape to an object includes a heated feeder which guides the tape/tow to a heated zone. The heated zone has a line compactor having a single row of at least one movable heated member. An area compactor is located in the heated zone downstream from the line compactor. The area compactor includes a plurality of rows of movable feet which are extendable toward the tape/tow different distances with respect to each other to conform to the shape of the object. A shim is located between the heated compactors and the tape/tow. A chilled compactor is in a chilled zone downstream from the heated zone. The chilled zone includes a line chilled compactor and an area chilled compactor. A chilled shim is mounted between the chilled compactor and the tape/tow.
Official Gazette of the U.S. Patent and Trademark Office
THERMOPLASTICITY; PLASTIC TAPES; POSITION (LOCATION)
20090002662 NASA, Washington, DC United States
Emission control system
Parrish, Clyde F., Inventor; July 29, 2008; In English
Patent Info.: May 11, 2004US-Patent-7,404,938; US-Patent-Appl-SN-10/845,418
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002662
Methods and apparatus utilizing hydrogen peroxide are useful to reduce NOx, SOx and mercury (or other heavy metal) emissions from combustion flue gas streams. Continuous concentration of hydrogen peroxide to levels approaching or exceeding propellant-grade hydrogen peroxide facilitates increased system efficiency. In this manner, combustion flue gas streams can be treated for the removal of NOx, SOx and heavy metals, while isolating useful by-products streams of sulfuric acid and nitric acid as well as solids for the recovery of the heavy metals.
Official Gazette of the U.S. Patent and Trademark Office
NITROGEN OXIDES; SULFURIC ACID; HYDROGEN PEROXIDE; FLUE GASES; MATERIALS RECOVERY; METAL COMBUSTION; NITRIC ACID
20090002663 NASA, Washington, DC United States
System and method for determining velocity of electrically conductive fluid
Polzin, Kurt A., Inventor; Korman, Valentin, Inventor; Markusic, Thomas E., Inventor; Stanojev, Boris Johann, Inventor; August 12, 2008; In English
Patent Info.: September 27, 2007US-Patent-7,409,875; US-Patent-Appl-SN-11/862,793
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002663
A flowing electrically-conductive fluid is controlled between an upstream and downstream location thereof to insure that a convection timescale of the flowing fluid is less than a thermal diffusion timescale of the flowing fluid. First and second nodes of a current-carrying circuit are coupled to the fluid at the upstream location. A current pulse is applied to the current-carrying circuit so that the current pulse travels through the flowing fluid to thereby generate a thermal feature therein at the upstream location. The thermal feature is convected to the downstream location where it is monitored to detect a peak associated with the thermal feature so-convected. The velocity of the fluid flow is determined using a time-of-flight analysis.
Official Gazette of the U.S. Patent and Trademark Office
FLOW VELOCITY; FLUID FLOW; ELECTRIC CURRENT; ELECTRICAL RESISTIVITY; THERMAL DIFFUSION
20090002664 Stanford Univ., Palo Alto, CA United States
Miniature trailing edge effector for aerodynamic control
Lee, Hak-Tae, Inventor; Bieniawski, Stefan R., Inventor; Kroo, Ilan M., Inventor; August 12, 2008; In English
Patent Info.: December 27, 2006US-Patent-7,410,133; US-Patent-Appl-SN-11/646,186
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002664
Improved miniature trailing edge effectors for aerodynamic control are provided. Three types of devices having aerodynamic housings integrated to the trailing edge of an aerodynamic shape are presented, which vary in details of how the control surface can move. A bucket type device has a control surface which is the back part of a C-shaped member having two arms connected by the back section. The C-shaped section is attached to a housing at the ends of the arms, and is rotatable about an axis parallel to the wing trailing edge to provide up, down and neutral states. A flip-up type device has a control surface which rotates about an axis parallel to the wing trailing edge to provide up, down, neutral and brake states. A rotating type device has a control surface which rotates about an axis parallel to the chord line to provide up, down and neutral states.
Official Gazette of the U.S. Patent and Trademark Office
TRAILING EDGES; AERODYNAMIC CONFIGURATIONS; CONTROL EQUIPMENT; CONTROL SURFACES; MINIATURIZATION; AERODYNAMICS
20090002665 NASA, Washington, DC United States
Directional microwave applicator and methods
Fink, Patrick W., Inventor; Lin, Greg Y., Inventor; Chu, Andrew W., Inventor; Dobbins, Justin A., Inventor; Arndt, G. Dickey, Inventor; Ngo, Phong H., Inventor; August 12, 2008; In English
Patent Info.: January 14, 2005US-Patent-7,410,485; US-Patent-Appl-SN-11/040,613
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002665
A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.
Official Gazette of the U.S. Patent and Trademark Office
MICROWAVE ANTENNAS; MINIATURIZATION; MEDICAL EQUIPMENT; CATHETERIZATION; AZIMUTH
20090002666 NASA, Washington, DC United States
Method for creating an aeronautic sound shield having gas distributors arranged on the engines, wings, and nose of an aircraft
Corda, Stephen, Inventor; Smith, Mark Stephen, Inventor; Myre, David Daniel, Inventor; August 5, 2008; In English
Patent Info.: November 14, 2005US-Patent-7,407,131; US-Patent-Appl-SN-11/288,052
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002666
The present invention blocks and/or attenuates the upstream travel of acoustic disturbances or sound waves from a flight vehicle or components of a flight vehicle traveling at subsonic speed using a local injection of a high molecular weight gas. Additional benefit may also be obtained by lowering the temperature of the gas. Preferably, the invention has a means of distributing the high molecular weight gas from the nose, wing, component, or other structure of the flight vehicle into the upstream or surrounding air flow. Two techniques for distribution are direct gas injection and sublimation of the high molecular weight solid material from the vehicle surface. The high molecular weight and low temperature of the gas significantly decreases the local speed of sound such that a localized region of supersonic flow and possibly shock waves are formed, preventing the upstream travel of sound waves from the flight vehicle.
Official Gazette of the U.S. Patent and Trademark Office
ACOUSTIC VELOCITY; SUBSONIC SPEED; UPSTREAM; AIRCRAFT NOISE; AERODYNAMIC NOISE; NOISE REDUCTION; SUPERSONIC FLOW
20090002667 NASA, Washington, DC United States
Unitized regenerative fuel cell system
Burke, Kenneth A., Inventor; August 12, 2008; In English
Patent Info.: July 15, 2004US-Patent-7,410,714; US-Patent-Appl-SN-10/891,599
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002667
A Unitized Regenerative Fuel Cell system uses heat pipes to convey waste heat from the fuel cell stack to the reactant storage tanks. The storage tanks act as heat sinks/sources and as passive radiators of the waste heat from the fuel cell stack. During charge up, i.e., the electrolytic process, gases are conveyed to the reactant storage tanks by way of tubes that include dryers. Reactant gases moving through the dryers give up energy to the cold tanks, causing water vapor in with the gases to condense and freeze on the internal surfaces of the dryer. During operation in its fuel cell mode, the heat pipes convey waste heat from the fuel cell stack to the respective reactant storage tanks, thereby heating them such that the reactant gases, as they pass though the respective dryers on their way to the fuel cell stacks retrieve the water previously removed.
Official Gazette of the U.S. Patent and Trademark Office
HEAT PIPES; REGENERATIVE FUEL CELLS; WASTE HEAT; HEAT SINKS; STORAGE TANKS
20090002668 California Inst. of Tech., Pasadena, CA United States
High throughput reconfigurable data analysis system
Bearman, Greg, Inventor; Pelletier, Michael J., Inventor; Seshadri, Suresh, Inventor; Pain, Bedabrata, Inventor; December 30, 2008; In English
Contract(s)/Grant(s): NAS7-03001
Patent Info.: January 16, 2004US-Patent-7,471,831; US-Patent-Appl-SN-10/759,808
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002668
The present invention relates to a system and method for performing rapid and programmable analysis of data. The present invention relates to a reconfigurable detector comprising at least one array of a plurality of pixels, where each of the plurality of pixels can be selected to receive and read-out an input. The pixel array is divided into at least one pixel group for conducting a common predefined analysis. Each of the pixels has a programmable circuitry programmed with a dynamically configurable user-defined function to modify the input. The present detector also comprises a summing circuit designed to sum the modified input.
Official Gazette of the U.S. Patent and Trademark Office
DATA PROCESSING; CIRCUITS; PIXELS
Additions to the NASA Aeronautics and Space Database as of 01/29/2009
20090002670 NASA Goddard Space Flight Center, Greenbelt, MD, United States
On-Orbit Maintenance of a Short Duration Mission: Space Technology 5
Calder, Alexander C.; November 13, 2008; In English; Flight Software Workshop 2008, 13-14 Nov. 2008, Laurel, MD, United States; Original contains color illustrations
Contract(s)/Grant(s): NNG04CA30D
Copyright; Avail.: CASI: A03, Hardcopy
This viewgraph presentation contains an overview of the the Space Technology 5 (ST5) mission, a review of the Post-separation anomaly that occurred, and the patches and work-arounds that were implemented to correct the problems caused by the anomaly. The events that involved multi-bit errors and the actions that occurred to correct these are also reviewed.
CASI
SOFTWARE ENGINEERING; ERRORS; INTEGRITY; AIRBORNE/SPACEBORNE COMPUTERS; ONBOARD DATA PROCESSING; SPACECRAFT ELECTRONIC EQUIPMENT; SIGNAL PROCESSING
20090002674 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Implementation of Complex Signal Processing Algorithms for Position-Sensitive Microcalorimeters
Smith, Stephen J.; [2008]; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNH06CC03B
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002674
We have recently reported on a theoretical digital signal-processing algorithm for improved energy and position resolution in position-sensitive, transition-edge sensor (POST) X-ray detectors [Smith et al., Nucl, lnstr and Meth. A 556 (2006) 2371. PoST's consists of one or more transition-edge sensors (TES's) on a large continuous or pixellated X-ray absorber and are under development as an alternative to arrays of single pixel TES's. PoST's provide a means to increase the field-of-view for the fewest number of read-out channels. In this contribution we extend the theoretical correlated energy position optimal filter (CEPOF) algorithm (originally developed for 2-TES continuous absorber PoST's) to investigate the practical implementation on multi-pixel single TES PoST's or Hydras. We use numerically simulated data for a nine absorber device, which includes realistic detector noise, to demonstrate an iterative scheme that enables convergence on the correct photon absorption position and energy without any a priori assumptions. The position sensitivity of the CEPOF implemented on simulated data agrees very well with the theoretically predicted resolution. We discuss practical issues such as the impact of random arrival phase of the measured data on the performance of the CEPOF. The CEPOF algorithm demonstrates that full-width-at- half-maximum energy resolution of < 8 eV coupled with position-sensitivity down to a few 100 eV should be achievable for a fully optimized device.
Author
SIGNAL PROCESSING; X RAY DETECTORS; CALORIMETERS; ALGORITHMS
20090002675 NASA Johnson Space Center, Houston, TX, United States
Fatigue Crack Growth in Peened Friction Stir Welds
Forth, Scott C.; Hatamleh, Omar; December 15, 2008; In English; International Conference on Laser Peening, 15-17 Dec. 2008, Houston, TX, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090002675
Friction stir welding induces residual stresses that accelerates fatigue crack growth in the weld nugget. Shot peening over the weld had little effect on growth rate. Laser peening over the weld retarded the growth rate: Final crack growth rate was comparable to the base, un-welded material. Crack tunneling evident from residual compressive stresses. 2195-T8 fracture surfaces were highly textured. Texturing makes comparisons difficult as the material system is affecting the data as much as the processing. Material usage becoming more common in space applications requiring additional work to develop useful datasets for damage tolerance analyses.
Author
FRICTION STIR WELDING; RESIDUAL STRESS; FATIGUE (MATERIALS); WELDED JOINTS; SHOT PEENING
20090003203 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Evolution of the Earth Observing System (EOS) Data and Information System (EOSDIS)
Ramapriyan, Hampapuram K.; Behnke, Jeanne; Sofinowski, Edwin; Lowe, Dawn; Esfandiari, Mary Ann; [2008]; In English
Contract(s)/Grant(s): NNG05CA99C
Copyright; Avail.: CASI: A03, Hardcopy
One of the strategic goals of the U.S. National Aeronautics and Space Administration (NASA) is to "Develop a balanced overall program of science, exploration, and aeronautics consistent with the redirection of the human spaceflight program to focus on exploration". An important sub-goal of this goal is to "Study Earth from space to advance scientific understanding and meet societal needs." NASA meets this subgoal in partnership with other U.S. agencies and international organizations through its Earth science program. A major component of NASA s Earth science program is the Earth Observing System (EOS). The EOS program was started in 1990 with the primary purpose of modeling global climate change. This program consists of a set of space-borne instruments, science teams, and a data system. The instruments are designed to obtain highly accurate, frequent and global measurements of geophysical properties of land, oceans and atmosphere. The science teams are responsible for designing the instruments as well as scientific algorithms to derive information from the instrument measurements. The data system, called the EOS Data and Information System (EOSDIS), produces data products using those algorithms as well as archives and distributes such products. The first of the EOS instruments were launched in November 1997 on the Japanese satellite called the Tropical Rainfall Measuring Mission (TRMM) and the last, on the U.S. satellite Aura, were launched in July 2004. The instrument science teams have been active since the inception of the program in 1990 and have participation from Brazil, Canada, France, Japan, Netherlands, United Kingdom and U.S. The development of EOSDIS was initiated in 1990, and this data system has been serving the user community since 1994. The purpose of this chapter is to discuss the history and evolution of EOSDIS since its beginnings to the present and indicate how it continues to evolve into the future. this chapter is organized as follows. Sect. 7.2 provides a discussion of EOSDIS, its elements and their functions. Sect. 7.3 provides details regarding the move towards more distributed systems for supporting both the core and community needs to be served by NASA Earth science data systems. Sect. 7.4 discusses the use of standards and interfaces and their importance in EOSDIS. Sect. 7.5 provides details about the EOSDIS Evolution Study. Sect. 7.6 presents the implementation of the EOSDIS Evolution plan. Sect. 7.7 briefly outlines the progress that the implementation has made towards the 2015 Vision, followed by a summary in Sect. 7.8.
Derived from text
CLIMATOLOGY; EARTH OBSERVATIONS (FROM SPACE); EARTH OBSERVING SYSTEM (EOS); EOS DATA AND INFORMATION SYSTEM; SATELLITE OBSERVATION
20090003205 Maryland Univ. Baltimore County, Baltimore, MD, United States
Precipitation Climatology over Mediterranean Basin from Ten Years of TRMM Measurements
Mehta, Amita V.; Yang, Song; June 2008; In English
Copyright; Avail.: CASI: A02, Hardcopy
Climatological features of mesoscale rain activities over the Mediterranean region between 5 W-40 E and 28 N-48 N are examined using the Tropical Rainfall Measuring Mission (TRMM) 3B42 and 2A25 rain products. The 3B42 rainrates at 3-hourly, 0.25 deg x 0.25 deg spatial resolution for the last 10 years (January 1998 to July 2007) are used to form and analyze the 5-day mean and monthly mean climatology of rainfall. Results show considerable regional and seasonal differences of rainfall over the Mediterranean Region. The maximum rainfall (3-5 mm/day) occurs over the mountain regions of Europe, while the minimum rainfall is observed over North Africa (approximately 0.5 mm/day). The main rainy season over the Mediterranean Sea extends from October to March, with maximum rainfall occurring during November-December. Over the Mediterranean Sea, an average rainrate of approximately 1-2 mm/day is observed, but during the rainy season there is 20% larger rainfall over the western Mediterranean Sea than that over the eastern Mediterranean Sea. During the rainy season, mesoscale rain systems generally propagate from west to east and from north to south over the Mediterranean region, likely to be associated with Mediterranean cyclonic disturbances resulting from interactions among large-scale circulation, orography, and land-sea temperature contrast.
Author
CLIMATOLOGY; MEDITERRANEAN SEA; MESOSCALE PHENOMENA; RAIN; METEOROLOGY; PRECIPITATION MEASUREMENT
20090003206 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Fomalhaut's Debris Disk and Planet: Constraining the Mass of Formalhaut B from Disk Morphology
Chiang, E.; Kite, E.; Kalas, P.; Graham, J. R.; Clampin, M.; November 19, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NSF AST-0507805
Copyright; Avail.: CASI: A03, Hardcopy
Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M(sub pl) < 3M(sub J), an orbital semimajor axis a(sub pl) > 101.5AU, and an orbital eccentricity e(sub pl) = 0.11 - 0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a approximately equals 133AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e approximately equals 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of approximately 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to approximately 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties are difficult to quantify. Even if the apsidal misalignment proves real, our calculated upper mass limit of 3 M(sub J) still holds. Parent bodies are evacuated from mean-motion resonances with Fom b; these empty resonances are akin to the Kirkwood gaps opened by Jupiter. The belt contains at least 3M(sub Earth) of solids that are grinding down to dust, their velocity dispersions stirred so strongly by Fom b that collisions are destructive. Such a large mass in solids is consistent with Fom b having formed in situ.
Author
ASTROMETRY; PLANETARY SYSTEMS; STELLAR ENVELOPES; PROTOPLANETARY DISKS; STARS; CELESTIAL MECHANICS
20090003207 NASA Goddard Space Flight Center, Greenbelt, MD, United States
James Webb Space Telescope: Frequently Asked Questions for Scientists and Engineers
Gardner, Jonathan P.; November 25, 2008; In English; Original contains black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090003207
JWST will be tested incrementally during its construction, starting with individual mirrors and instruments (including cameras and spectrometers) and building up to the full observatory. JWST's mirrors and the telescope structure are first each tested individually, including optical testing of the mirrors and alignment testing of the structure inside a cold thermal-vacuum chamber. The mirrors are then installed on the telescope structure in a clean room at Goddard Space Flight Center (GSFC). In parallel to the telescope assembly and alignment, the instruments are being built and tested, again first individually, and then as part of an integrated instrument assembly. The integrated instrument assembly will be tested in a thermal-vacuum chamber at GSFC using an optical simulator of the telescope. This testing makes sure the instruments are properly aligned relative to each other and also provides an independent check of the individual tests. After both the telescope and the integrated instrument module are successfully assembled, the integrated instrument module will be installed onto the telescope, and the combined system will be sent to Johnson Space Flight Center (JSC) where it will be optically tested in one of the JSC chambers. The process includes testing the 18 primary mirror segments acting as a single primary mirror, and testing the end-to-end system. The final system test will assure that the combined telescope and instruments are focused and aligned properly, and that the alignment, once in space, will be within the range of the actively controlled optics. In general, the individual optical tests of instruments and mirrors are the most accurate. The final system tests provide a cost-effective check that no major problem has occurred during assembly. In addition, independent optical checks of earlier tests will be made as the full system is assembled, providing confidence that there are no major problems.
Author
JAMES WEBB SPACE TELESCOPE; END-TO-END DATA SYSTEMS; OPTICAL EQUIPMENT; TELESCOPES; CAMERAS; ALIGNMENT
Additions to the NASA Aeronautics and Space Database as of 01/30/2009
20090004148 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Annular and Total Solar Eclipses of 2010
Espenak, Fred; Anderson, J.; November 2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TP-2008-214171; No Copyright; Avail.: CASI: A05, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004148
While most NASA eclipse bulletins cover a single eclipse, this publication presents predictions for two solar eclipses during 2010. This has required a different organization of the material into the following Eclipse Predictions: The section consists of a general discussion about the eclipse path maps, Besselian elements, shadow contacts, eclipse path tables, local circumstances tables, and the lunar limb profile. Solar Eclipse of 2010 Jan 15: The section covers predictions and weather prospects for the annular eclipse. Total Solar Eclipse of 2010 Jul 11: The section covers predictions and weather prospects for the total eclipse. provides information on eye safety, solar filters, eclipse photography, and making contact timings from the path limits. contains a number of resources including information on the IAU Working Group on Eclipses, the Solar Eclipse Mailing List, the NASA eclipse bulletins on the Internet, Web sites for the two 2010 eclipses, and a summary identifying the algorithms, ephemerides, predictions.
Derived from text
IDENTIFYING; SOLAR ECLIPSES; PREDICTIONS
20090004155 NASA Johnson Space Center, Houston, TX, United States
Air Quality Monitoring: Risk-Based Choices
James, John T.; Jan. 15, 2009; In English; NASA Human Health and Performance Technology, 15 Jan. 2009, Houston, TX, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004155
Air monitoring is secondary to rigid control of risks to air quality. Air quality monitoring requires us to target the credible residual risks. Constraints on monitoring devices are severe. Must transition from archival to real-time, on-board monitoring. Must provide data to crew in a way that they can interpret findings. Dust management and monitoring may be a major concern for exploration class missions.
Author
AIR QUALITY; TARGETS; RISK; REAL TIME OPERATION
20090004160 NASA Johnson Space Center, Houston, TX, United States
Human Performance in Extreme Environments
Williams, Sunita; Fiedler, Edna R.; Harrison, Albert A.; [2008]; In English
Copyright; Avail.: CASI: A03, Hardcopy
Even on a bad day, looking down from orbit is a powerful and enjoyable experience, enhanced by the knowledge that time in orbit represents only a tiny fraction of one's life. You look down at Earth and you feel a sense of peace and solidarity. You look at the stars, and because they are not obscured by atmosphere, they are far more abundant than you realized, and they shine very bright. Later on you will reflect on this as one of life's greatest moments. Today astronauts and a few wealthy space tourists have been able to experience staying on the International Space Station. As representatives of humankind in space, astronauts have to get out there and tell people what it's like, and to encourage successive generations of children to consider careers in space. Perhaps the more people who can experience this view, the nicer we will all be to one another. Astronauts must speak authoritatively, without arrogance or a lack of humility. Each astronaut is an emissary who can share his or her experiences and educate people who will not have the opportunity to fly in space. This chapter is a part of that communication process.
Author
ASTRONAUTS; SPACE EXPLORATION; VISUAL OBSERVATION; COMMUNICATION
20090004167 NASA Johnson Space Center, Houston, TX, United States
Spaceflight Toxicology
Meyers, Valerie; December 12, 2008; In English; Original contains color illustrations
Copyright; Avail.: CASI: A02, Hardcopy
This viewgraph presentation provides a review of NASA Johnson Space Center's Toxicology program. The mission of this program is to protect crews from toxic exposures during spaceflight. The presentation reviews some of the health hazards. A toxicological hazard level chart is presented that reviews the rating of hazard level, irritancy, systemic effects and containability. The program also participates in the Lunar Airborne Dust Toxicity Advisory Group.
CASI
NASA SPACE PROGRAMS; SPACE FLIGHT; TOXICITY; TOXICOLOGY; TOXIC HAZARDS; HAZARDS
20090004168 NASA Goddard Space Flight Center, Greenbelt, MD, United States
In-Flight Anomalies and Radiation Performance of NASA Missions - Selected Lessons Learned
LaBel, Kenneth A.; November 30, 2008; In English; 4th International School in the Effects of Radiation on Embedded Systems for Space applicatoins (SERESSA), 30 Nov. - 5 Dec. 2008, West Palm Beach, FL, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004168
This presentation addresses in-flight electronic disturbances and radiation, specifically anomaly resolution. The process for anomaly review takes into account the environment, selected parts and design, existing and/or new radiation test data, risk probability and actions to be taken. Noise spikes and the meaning of upset in a fiber optic link are also discussed.
Derived from text
NASA SPACE PROGRAMS; SPACECRAFT ELECTRONIC EQUIPMENT; EXTRATERRESTRIAL RADIATION; RADIATION TOLERANCE; LESSONS LEARNED; ASTRIONICS; FAILURE ANALYSIS
20090004193 NASA, Washington, DC, United States
Exploring the Unknown; Selected Documents in the History of the U.S. Civil Space Program Volume 7 Human Spaceflight: Projects Mercury, Gemini, and Apollo
Logsdon, John M., Editor; Launius, Roger D., Editor; 2008; In English; Original contains black and white illustrations
Report No.(s): NASA-SP-2008-4407; No Copyright; Avail.: CASI: A99, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004193
The extension of human activity into outer space has been accompanied by a high degree of self-awareness of its historical significance. Few large-scale activities have been as extensively chronicled so closely to the time they actually occurred. Many of those who were directly involved were quite conscious that they were making history, and they kept full records of their activities. Because most of the activity in outer space was carried out under government sponsorship, it was accompanied by the documentary record required of public institutions, and there has been a spate of official and privately written histories of most major aspects of space achievement to date. When top leaders considered what course of action to pursue in space, their deliberations and decisions often were carefully put on the record. There is, accordingly, no lack of material for those who aspire to understand the origins and evolution of U.S. space policies and programs.The documents selected for inclusion in this volume are presented in two chapters: one covering the Mercury and Gemini projects and another chapter covering Project Apollo. Each section in the present volume is introduced by an overview essay. In the main, these essays are intended to introduce and complement the documents in the section and to place them in a chronological and substantive context. Each essay contains references to the documents in the section it introduces, and also contains references to documents in other volumes in this series.
Derived from text
HISTORIES; MERCURY PROJECT; GEMINI PROJECT; DOCUMENTS; NASA SPACE PROGRAMS
20090004198 NASA Johnson Space Center, Houston, TX, United States
Spacecraft Water Monitoring: Adapting to an Era of Emerging Scientific Challenges
McCoy, J. Torin; [2009]; In English; NASA Human Health and Performances Technology Workshop, 15 Jan. 2009, Houston, TX, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004198
This viewgraph presentation reviews spacecraft water monitoring, and the scientific challenges associated with spacecraft water quality. The contents include: 1) Spacecraft Water 101; 2) Paradigm Shift; and 3) Technology Needs.
CASI
WATER QUALITY; ENVIRONMENTAL TESTS; INTERNATIONAL SPACE STATION; SPACECRAFT ENVIRONMENTS
20090004212 Rice Univ., Houston, TX United States
Functionalized carbon nanotube-polymer composites and interactions with radiation
Barrera, Enrique V., Inventor; Wilkins, Richard, Inventor; Shofner, Meisha, Inventor; Pulikkathara, Merlyn X., Inventor; Vaidyanathan, Ranjii, Inventor; August 5, 2008; In English
Contract(s)/Grant(s): NAS2-02102NCC1-02038
Patent Info.: November 25, 2003US-Patent-7,407,640; US-Patent-Appl-SN-10/536,688
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004212
The present invention involves the interaction of radiation with functionalized carbon nanotubes that have been incorporated into various host materials, particularly polymeric ones. The present invention is directed to chemistries, methods, and apparatuses which exploit this type of radiation interaction, and to the materials which result from such interactions. The present invention is also directed toward the time dependent behavior of functionalized carbon nanotubes in such composite systems.
Official Gazette of the U.S. Patent and Trademark Office
CARBON NANOTUBES; TIME DEPENDENCE
20090004213
Dynamic refractometer
Curley, Michael J., Inventor; Sarkisov, Sergey S., Inventor; November 25, 2008; In English
Contract(s)/Grant(s): NAG8-1880
Patent Info.: October 17, 2006US-Patent-7,456,942; US-Patent-Appl-SN-11/582,625
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004213
A refractometer computer controls the rotation of a rotary plate upon which are mounted a prism optically coupled via an optical window to a spectroscopic cell holding a resin exhibiting a dynamic refractive index during photocuring. The computer system positions the prism and spectroscopic cell relative to a visible light laser which illuminates the prism-resin interface at selected incidence angles. A photodetector mounted on the plate generates a signal to the computer proportional to intensity of an internally reflected light beam. A curing light is selectively transmitted through the prism and into the photocurable resin. The refractometer determines the intensity of the internally reflected beam a selected incidence angles and determines the effective refractive index curve of the resin at an uncured state and, optionally, at a completely cured state. Next, an amount of uncured resin and selected optical components to be joined by the resin is placed in the spectroscopic cell and irradiated with the UV light. The refractometer is fixed at a selected incidence angle and measures the intensity of an internally reflected light beam of light throughout the cure cycle. The refractometer determines the resin's refractive index of the polymeric mixture by means of extrapolation of a horizontal shift in the effective refractive index curve of the resin from an uncured state to a selected point in the cure cycle.
Official Gazette of the U.S. Patent and Trademark Office
REFRACTOMETERS; ROTATION; OPTICAL EQUIPMENT; PRISMS; REFRACTIVITY
20090004214 NASA, Washington, DC United States
Variable area nozzle including a plurality of convexly vanes with a crowned contour, in a vane to vane sealing arrangement and with nonuniform lengths
Arnold, Steven M., Inventor; Penney, Nicholas, Inventor; December 2, 2008; In English
Patent Info.: October 23, 2003US-Patent-7,458,221; US-Patent-Appl-SN-10/693,850
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004214
A variable area nozzle comprising a concentric support and a plurality of convexly contoured self sealing vanes is disclosed and claimed. The vanes are circumferentially and rotatably mounted to the concentric support forming a nozzle infinitely positionable between a first position corresponding to a minimum area nozzle and a second position corresponding to a maximum area nozzle. A closer, which is preferably a shape memory alloy (SMA), urges the nozzle toward the first position corresponding to a minimum area nozzle. Periodically spaced openers act between adjacent vanes to urge the nozzle to a second position corresponding to a maximum area nozzle.
Official Gazette of the U.S. Patent and Trademark Office
VANES; CONTOURS; SELF SEALING; SHAPE MEMORY ALLOYS; NOZZLES
20090004215 Drexel Univ., Philadelphia, PA United States
Piezoelectric cantilever sensors
Shih, Wan Y., Inventor; Shih, Wei-Heng, Inventor; Shen, Zuyan, Inventor; December 2, 2008; In English
Contract(s)/Grant(s): NAG2-1475
Patent Info.: October 27, 2004US-Patent-7,458,265; US-Patent-Appl-SN-10/595,570
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004215
A piezoelectric cantilever with a non-piezoelectric, or piezoelectric tip useful as mass and viscosity sensors. The change in the cantilever mass can be accurately quantified by monitoring a resonance frequency shift of the cantilever. For bio-detection, antibodies or other specific receptors of target antigens may be immobilized on the cantilever surface, preferably on the non-piezoelectric tip. For chemical detection, high surface-area selective absorbent materials are coated on the cantilever tip. Binding of the target antigens or analytes to the cantilever surface increases the cantilever mass. Detection of target antigens or analytes is achieved by monitoring the cantilever's resonance frequency and determining the resonance frequency shift that is due to the mass of the adsorbed target antigens on the cantilever surface. The use of a piezoelectric unimorph cantilever allows both electrical actuation and electrical sensing. Incorporating a non-piezoelectric tip (14) enhances the sensitivity of the sensor. In addition, the piezoelectric cantilever can withstand damping in highly viscous liquids and can be used as a viscosity sensor in wide viscosity range.
Official Gazette of the U.S. Patent and Trademark Office
PIEZOELECTRICITY; LEVERS; RESONANT FREQUENCIES; DETECTION; LIQUIDS
20090004216 City Univ. of New York, NY United States
Cr.sup.3+-doped laser materials and lasers and methods of making and using
Alfano, Robert R., Inventor; Bykov, Alexey, Inventor; Petricevic, Vladimir, Inventor; Sharonov, Mikhail, Inventor; December 2, 2008; In English
Contract(s)/Grant(s): NCC1-03009
Patent Info.: January 24, 2006US-Patent-7,460,574; US-Patent-Appl-SN-11/338,341
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004216
A laser medium includes a single crystal of chromium-doped LiSc.sub.l-xIn.sub.xGe.sub.1-ySi.sub.yO.sub.4, where 0.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1. Preferably, x and y are not both 0. A laser, such as a tunable near infrared laser, can contain the laser medium.
Official Gazette of the U.S. Patent and Trademark Office
TUNABLE LASERS; DOPED CRYSTALS; CHROMIUM; LASER MATERIALS; NEAR INFRARED RADIATION
20090004218 California Inst. of Tech., Pasadena, CA United States
System and method for suppressing sublimation using opacified aerogel
Sakamoto, Jeff S., Inventor; Snyder, G. Jeffrey, Inventor; Calliat, Thierry, Inventor; Fleurial, Jean-Pierre, Inventor; Jones, Steven M., Inventor; Palk, Jong-Ah, Inventor; December 9, 2008; In English
Patent Info.: October 29, 2004US-Patent-7,461,512; US-Patent-Appl-SN-10/977,276
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004218
The present invention relates to a castable, aerogel-based, ultra-low thermal conductivity opacified insulation to suppress sublimation. More specifically, the present invention relates to an aerogel opacified with various opacifying or reflecting constituents to suppress sublimation and provide thermal insulation in thermoelectric modules. The opacifying constituent can be graded within the aerogel for increased sublimation suppression, and the density of the aerogel can similarly be graded to achieve optimal thermal insulation and sublimation suppression.
Official Gazette of the U.S. Patent and Trademark Office
THERMAL INSULATION; OPACITY; SUBLIMATION; THERMAL CONDUCTIVITY; AEROGELS; MODULES
20090004219 NASA, Washington, DC United States
Advanced resistive exercise device
Raboin, Jasen L., Inventor; Niebuhr, Jason, Inventor; Cruz, Santana F., Inventor; Lamoreaux, Christopher D., Inventor; December 9, 2008; In English
Patent Info.: January 6, 2005US-Patent-7,462,141; US-Patent-Appl-SN-11/031,942
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004219
The present invention relates to an exercise device, which includes a vacuum cylinder and a flywheel. The flywheel provides an inertial component to the load, which is particularly well suited for use in space as it simulates exercising under normal gravity conditions. Also, the present invention relates to an exercise device, which has a vacuum cylinder and a load adjusting armbase assembly.
Official Gazette of the U.S. Patent and Trademark Office
PHYSICAL EXERCISE; LOADS (FORCES); FLYWHEELS; GRAVITATION
20090004220 NASA, Washington, DC United States
Analyzing nonstationary financial time series via hilbert-huang transform (HHT)
Huang, Norden E., Inventor; December 9, 2008; In English
Patent Info.: October 7, 2004US-Patent-7,464,006; US-Patent-Appl-SN-10/963,470
No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004220
An apparatus, computer program product and method of analyzing non-stationary time varying phenomena. A representation of a non-stationary time varying phenomenon is recursively sifted using Empirical Mode Decomposition (EMD) to extract intrinsic mode functions (IMFs). The representation is filtered to extract intrinsic trends by combining a number of IMFs. The intrinsic trend is inherent in the data and identifies an IMF indicating the variability of the phenomena. The trend also may be used to detrend the data.
Official Gazette of the U.S. Patent and Trademark Office
HILBERT TRANSFORMATION; TIME SERIES ANALYSIS; COMPUTER PROGRAMS; EXTRACTION
20090004221 Boeing Co., Chicago, IL United States
Folding retractable protective dome for space vehicle equipment
Clark, Paul R., Inventor; Messinger, Ross H., Inventor; December 16, 2008; In English
Contract(s)/Grant(s): NAS8-01099
Patent Info.: October 20, 2004US-Patent-7,464,900; US-Patent-Appl-SN-10/970,472
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004221
A folding, retractable dome for protecting a feature, such as a docking mechanism, a hatch or other equipment at an exterior surface of a space vehicle, includes a plurality of arcuate ribs, each having opposite ends respectively pinioned at opposite sides of the feature at the surface of the vehicle for rotational movement about an axis of rotation extending through the opposite ends and through an arcuate path of revolution extending over the feature, and a flexible cover attached to each of the ribs such that, in a deployed configuration of the dome, in which adjacent ribs are rotated apart from each other at a maximum relative angle therebetween, the cover is stretched generally tangentially between the adjacent ribs to form a generally arcuate shield over the feature, and in a retracted position of the dome, in which adjacent ribs are rotated together at a minimum relative angle therebetween, the cover is collapsed to define folded pleats between the adjacent ribs.
Official Gazette of the U.S. Patent and Trademark Office
RETRACTABLE EQUIPMENT; SURFACE VEHICLES; HATCHES; DOCKING; FOLDING
20090004222 Massachusetts Inst. of Tech., Cambridge, MA United States
Nanocomposites with high thermoelectric figures of merit
Chen, Gang, Inventor; Ren, Zhifeng, Inventor; Dresselhaus, Mildred, Inventor; December 16, 2008; In English
Contract(s)/Grant(s): NAS3-03108
Patent Info.: October 29, 2004US-Patent-7,465,871; US-Patent-Appl-SN-10/977,363
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004222
The present invention is generally directed to nanocomposite thermoelectric materials that exhibit enhanced thermoelectric properties. The nanocomposite materials include two or more components, with at least one of the components forming nano-sized structures within the composite material. The components are chosen such that thermal conductivity of the composite is decreased without substantially diminishing the composite's electrical conductivity. Suitable component materials exhibit similar electronic band structures. For example, a band-edge gap between at least one of a conduction band or a valence band of one component material and a corresponding band of the other component material at interfaces between the components can be less than about 5k.sub.BT, wherein k.sub.B is the Boltzman constant and T is an average temperature of said nanocomposite composition.
Official Gazette of the U.S. Patent and Trademark Office
THERMOELECTRICITY; THERMOELECTRIC MATERIALS; COMPOSITE MATERIALS; ENERGY GAPS (SOLID STATE); NANOCOMPOSITES
20090004223 NASA, Washington, DC United States
Device system and method for miniaturized radiation spectrometer
Stassinopoulos, Epaminondas G., Inventor; December 16, 2008; In English
Patent Info.: September 29, 2006US-Patent-7,465,926; US-Patent-Appl-SN-11/537,280
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004223
A device/system for radiation sensing is configured to detect high and low LET radiation. The radiation sensing system may include a high LET detector and a low LET detector coupled to the high LET detector by a CPU, wherein the high LET detector and the low LET detector are assembled within a single unit. The device/system may also include a high LET and low LET detector that may be coupled together without an internal CPU. Overall, the device/system may be a stand-alone system and/or coupled to an external processing device. The device/system may also be approximately 6.times.6.times.2 cm.sup.3 in size, making it hand portable and may weigh less or equal to approximately ninety (90) grams, and operate on less than or approximately 0.25 watts of power.
Official Gazette of the U.S. Patent and Trademark Office
RADIATION DETECTORS; MINIATURIZATION; SPECTROMETERS; DETECTION
20090004224 Nebraska Univ., Omaha, NE United States
Digital X-ray camera for quality evaluation three-dimensional topographic reconstruction of single crystals of biological macromolecules
Borgstahl, Gloria, Inventor; Lovelace, Jeff, Inventor; Snell, Edward Holmes, Inventor; Bellamy, Henry, Inventor; December 16, 2008; In English
Contract(s)/Grant(s): NAG8-1825
Patent Info.: April 5, 2006US-Patent-7,466,798; US-Patent-Appl-SN-11/278,738
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004224
The present invention provides a digital topography imaging system for determining the crystalline structure of a biological macromolecule, wherein the system employs a charge coupled device (CCD) camera with antiblooming circuitry to directly convert x-ray signals to electrical signals without the use of phosphor and measures reflection profiles from the x-ray emitting source after x-rays are passed through a sample. Methods for using said system are also provided.
Official Gazette of the U.S. Patent and Trademark Office
DIGITAL CAMERAS; SINGLE CRYSTALS; CHARGE COUPLED DEVICES; CCD CAMERAS; IMAGING TECHNIQUES; TOPOGRAPHY
20090004225 NASA, Washington, DC United States
Positioning system for single or multi-axis sensitive instrument calibration and calibration system for use therewith
Finley, Tom D., Inventor; Parker, Peter A., Inventor; December 23, 2008; In English
Patent Info.: June 30, 2006US-Patent-7,467,536; US-Patent-Appl-SN-11/428,017
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004225
A positioning and calibration system are provided for use in calibrating a single or multi axis sensitive instrument, such as an inclinometer. The positioning system includes a positioner that defines six planes of tangential contact. A mounting region within the six planes is adapted to have an inclinometer coupled thereto. The positioning system also includes means for defining first and second flat surfaces that are approximately perpendicular to one another with the first surface adapted to be oriented relative to a local or induced reference field of interest to the instrument being calibrated, such as a gravitational vector. The positioner is positioned such that one of its six planes tangentially rests on the first flat surface and another of its six planes tangentially contacts the second flat surface. A calibration system is formed when the positioning system is used with a data collector and processor.
Official Gazette of the U.S. Patent and Trademark Office
POSITIONING; CALIBRATING; FLAT SURFACES; ACCUMULATORS; DATA PROCESSING EQUIPMENT
Additions to the NASA Aeronautics and Space Database as of 02/02/2009
20090004415 Maryland Univ., College Park, MD, United States
Interim Report on Heuristics about Inspection Parameters: Updates to Heuristics Resulting from Refinement on Projects
Shull, Forrest; Seaman, Carolyn; Feldman, Raimund; Haingaertner, Ralf; Regardie, Myrna; September 30, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG05GE77G
Copyright; Avail.: CASI: A04, Hardcopy
In 2008, we have continued analyzing the inspection data in an effort to better understand the applicability and effect of the inspection heuristics on inspection outcomes. Our research goals during this period are: 1. Investigate the effect of anomalies in the dataset (e.g. the very large meeting length values for some inspections) on our results 2. Investigate the effect of the heuristics on other inspection outcome variables (e.g. effort) 3. Investigate whether the recommended ranges can be modified to give inspection planners more flexibility without sacrificing effectiveness 4. Investigate possible refinements or modifications to the heuristics for specific subdomains (partitioned, e.g., by size, domain, or Center) This memo reports our results to date towards addressing these goals. In the next section, the first goal is addressed by describing the types of anomalies we have found in our dataset, how we have addressed them, and the effect of these changes on our previously reported results. In the following section, on "methodology", we describe the analyses we have conducted to address the other three goals and the results of these analyses are described in the "results" section. Finally, we conclude with future plans for continuing our investigation.
Author
HEURISTIC METHODS; INSPECTION; DEFECTS
20090004416 NASA Stennis Space Center, Stennis Space Center, MS, United States
Land-use and Land-cover Change from 1974 to 2008 around Mobile Bay
Ellis, Jean; Spruce, Joseph; Smoot, James; Hilbert, Kent; Swann, Roberta; October 28, 2008; In English; Mississippi-Alabama Bays and Bayous Symposium 2008, 28-29 Oct. 2008, Biloxi, MS, United States; Original contains color illustrations
Report No.(s): SSTI-2220-0173; Copyright; Avail.: CASI: A01, Hardcopy
This project is a Gulf of Mexico Application Pilot in which NASA Stennis Space Center (SSC) is working within a regional collaboration network of the Gulf of Mexico Alliance. NASA researchers, with support from the NASA SSC Applied Science Program Steering Committee, employed multi-temporal Landsat data to assess land-use and land-cover (LULC) changes in the coastal counties of Mobile and Baldwin, AL, between 1974 and 2008. A multi-decadal time-series, coastal LULC product unique to NASA SSC was produced. The geographic extent and nature of change was quantified for the open water, barren, upland herbaceous, non-woody wetland, upland forest, woody wetland, and urban landscapes. The National Oceanic and Atmospheric Administration (NOAA) National Coastal Development Data Center (NCDDC) will assist with the transition of the final product to the operational end user, which primarily is the Mobile Bay National Estuary Program (MBNEP). We found substantial LULC change over the 34-year study period, much more than is evident when the change occurring in the last years. Between 1974 and 2008, the upland forest landscape lost almost 6% of the total acreage, while urban land cover increased by slightly more than 3%. With exception to open water, upland forest is the dominant landscape, accounting for about 25-30% of the total area.
Author
LAND USE; TOPOGRAPHY; TERRAIN; PERIODIC VARIATIONS; GULF OF MEXICO; SATELLITE IMAGERY; LANDSAT SATELLITES
20090004419 NASA Glenn Research Center, Cleveland, OH, United States
Spray Chemical Vapor Deposition of Single-Source Precursors for Chalcopyrite I-III-VI2 Thin-Film Materials
Hepp, Aloysius F.; Banger, Kulbinder K.; Jin, Michael H.-C.; Harris, Jerry D.; McNatt, Jeremiah S.; Dickman, John E.; November 2008; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNC04AA71A; NCC3-947WBS 953033.01.03.23
Report No.(s): NASA/TP-2008-214937; E-16162-1; Copyright; Avail.: CASI: A03, Hardcopy
Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure in a horizontal hotwall reactor at 395 C yielded the best device films. Placing the susceptor closer to the evaporation zone and flowing a more precursor-rich carrier gas through the reactor yielded shinier-, smoother-, and denser-looking films. Growth of (112)-oriented films yielded more Cu-rich films with fewer secondary phases than growth of (204)/(220)-oriented films. Post-deposition sulfur-vapor annealing enhanced stoichiometry and crystallinity of the films. Photoluminescence studies revealed four major emission bands and a broad band associated with deep defects. The highest device efficiency for an aerosol-assisted chemical vapor deposited cell was one percent.
Author
VAPOR DEPOSITION; THIN FILMS; SOLAR CELLS; SULFUR; DISULFIDES; PHOTOLUMINESCENCE
20090004420 NASA Glenn Research Center, Cleveland, OH, United States
Structural Benchmark Creep Testing for the Advanced Stirling Convertor Heater Head
Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.; Shah, Ashwin R.; November 2008; In English; Sixth International Energy Conversion Engineering Conference (IECEC), 28-30 Jul. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 138494.04.01.01
Report No.(s): NASA/TM-2008-215435; AIAA-2008-5774; Copyright; Avail.: CASI: A03, Hardcopy
The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for use on long duration Science missions such as lunar applications, Mars rovers, and deep space missions. For the inherent long life times required, a structurally significant design limit for the heater head component of the ASRG Advanced Stirling Convertor (ASC) is creep deformation induced at low stress levels and high temperatures. Demonstrating proof of adequate margins on creep deformation and rupture for the operating conditions and the MarM-247 material of construction is a challenge that the NASA Glenn Research Center is addressing. The combined analytical and experimental program ensures integrity and high reliability of the heater head for its 17-year design life. The life assessment approach starts with an extensive series of uniaxial creep tests on thin MarM-247 specimens that comprise the same chemistry, microstructure, and heat treatment processing as the heater head itself. This effort addresses a scarcity of openly available creep properties for the material as well as for the virtual absence of understanding of the effect on creep properties due to very thin walls, fine grains, low stress levels, and high-temperature fabrication steps. The approach continues with a considerable analytical effort, both deterministically to evaluate the median creep life using nonlinear finite element analysis, and probabilistically to calculate the heater head s reliability to a higher degree. Finally, the approach includes a substantial structural benchmark creep testing activity to calibrate and validate the analytical work. This last element provides high fidelity testing of prototypical heater head test articles; the testing includes the relevant material issues and the essential multiaxial stress state, and applies prototypical and accelerated temperature profiles for timely results in a highly controlled laboratory environment. This paper focuses on the last element and presents a preliminary methodology for creep rate prediction, the experimental methods, test challenges, and results from benchmark testing of a trial MarM-247 heater head test article. The results compare favorably with the analytical strain predictions. A description of other test findings is provided, and recommendations for future test procedures are suggested. The manuscript concludes with describing the potential impact of the heater head creep life assessment and benchmark testing effort on the ASC program.
Author
STIRLING CYCLE; CREEP PROPERTIES; DEFORMATION; CREEP RUPTURE STRENGTH; STEADY STATE CREEP; STRAIN RATE; LIFE (DURABILITY); HEAT TREATMENT; HEAT RESISTANT ALLOYS
20090004421 NASA Glenn Research Center, Cleveland, OH, United States
Assuring Life in Composite Systems
Chamis, Christos c.; November 2008; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.10.03.23
Report No.(s): NASA/TM-2008-215452; E-16526-1; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004421
A computational simulation method is presented to assure life in composite systems by using dynamic buckling of smart composite shells as an example. The combined use of composite mechanics, finite element computer codes, and probabilistic analysis enable the effective assessment of the dynamic buckling load of smart composite shells. A universal plot is generated to estimate the dynamic buckling load of composite shells at various load rates and probabilities. The shell structure is also evaluated with smart fibers embedded in the plies right below the outer plies. The results show that, on the average, the use of smart fibers improved the shell buckling resistance by about 9% at different probabilities and delayed the buckling occurrence time. The probabilistic sensitivities results indicate that uncertainties in the fiber volume ratio and ply thickness have major effects on the buckling load. The uncertainties in the electric field strength and smart material volume fraction have moderate effects and thereby in the assured life of the shell.
Author
COMPOSITE MATERIALS; BUCKLING; PROBABILITY THEORY; SHELLS (STRUCTURAL FORMS); DYNAMIC LOADS; COMPOSITE STRUCTURES; LOADS (FORCES)
20090004422 Cleveland State Univ., Cleveland, OH, United States
Effect of Adding a Regenerator to Kornhauser's MIT "Two-Space" (Gas-Spring+Heat Exchanger) Test Rig
Ebiana, Asuquo B.; Gidugu, Praveen; November 2008; In English; Sixth International Energy Conversion Engineering Conference (IECEC), 28-30 Jul. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC05AA24AWBS 138494.04.01.01
Report No.(s): NASA/CR-2008-215480; AIAA-2008-5718; E-16657; Copyright; Avail.: CASI: A04, Hardcopy
This study employed entropy-based second law post-processing analysis to characterize the various thermodynamic losses inside a 3-space solution domain (gas spring+heat exchanger+regenerator) operating under conditions of oscillating pressure and oscillating flow. The 3- space solution domain is adapted from the 2-space solution domain (gas spring+heat exchanger) in Kornhauser's MIT test rig by modifying the heat exchanger space to include a porous regenerator system. A thermal nonequilibrium model which assumes that the regenerator porous matrix and gas average temperatures can differ by several degrees at a given axial location and time during the cycle is employed. An important and primary objective of this study is the development and application of a thermodynamic loss post-processor to characterize the major thermodynamic losses inside the 3-space model. It is anticipated that the experience gained from thermodynamic loss analysis of the simple 3-space model can be extrapolated to more complex systems like the Stirling engine. It is hoped that successful development of loss post-processors will facilitate the improvement of the optimization capability of Stirling engine analysis codes through better understanding of the heat transfer and power losses. It is also anticipated that the incorporation of a successful thermal nonequilibrium model of the regenerator in Stirling engine CFD analysis codes, will improve our ability to accurately model Stirling regenerators relative to current multidimensional thermal-equilibrium porous media models.
Author
COMPUTATIONAL FLUID DYNAMICS; GAS EXCHANGE; HEAT EXCHANGERS; STIRLING ENGINES; THERMODYNAMIC EQUILIBRIUM; POSITION (LOCATION); OSCILLATING FLOW; HEAT TRANSFER; REGENERATORS
20090004439 NASA Glenn Research Center, Cleveland, OH, United States
Progress in NASA Rotorcraft Propulsion
DellaCorte, Christopher; Johnson, Susan M.; October 10, 2008; In English; Fundamental Aeronautics Meeting 2008, 7-9 Oct. 2008, Atlanta, GA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01
Report No.(s): E-16832; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004439
This presentation reviews recent progress made under NASA s Subsonic Rotary Wing (SRW) propulsion research activities. Advances in engines, drive systems and optimized propulsion systems are discussed. Progress in wide operability compressors, modeling of variable geometry turbine performance, foil gas bearings and multi-speed transmissions are presented.
Author
ROTARY WING AIRCRAFT; PROPULSION SYSTEM PERFORMANCE; PROPULSION SYSTEM CONFIGURATIONS; GAS BEARINGS; PERFORMANCE PREDICTION
20090004441 NASA Glenn Research Center, Cleveland, OH, United States
Evaluation of Recent Upgrades to the NESS (Nuclear Engine System Simulation) Code
Fittje, James E.; Schnitzler, Bruce G.; July 21, 2008; In English; 44th AIAA Joint Propulsion Conference, 21-23 Jul. 2008, Hartford, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07B
Report No.(s): E-16836; Copyright; Avail.: CASI: A03, Hardcopy
The Nuclear Thermal Rocket (NTR) concept is being evaluated as a potential propulsion technology for exploratory expeditions to the moon, Mars, and beyond. The need for exceptional propulsion system performance in these missions has been documented in numerous studies, and was the primary focus of a considerable effort undertaken during the Rover/NERVA program from 1955 to 1973. The NASA Glenn Research Center is leveraging this past NTR investment in their vehicle concepts and mission analysis studies with the aid of the Nuclear Engine System Simulation (NESS) code. This paper presents the additional capabilities and upgrades made to this code in order to perform higher fidelity NTR propulsion system analysis and design, and a comparison of its results to the Small Nuclear Rocket Engine (SNRE) design.
Author
PROPULSION SYSTEM PERFORMANCE; NUCLEAR ENGINE FOR ROCKET VEHICLES; COMPUTERIZED SIMULATION; SYSTEMS ANALYSIS; ROCKET ENGINE DESIGN; NUCLEAR ROCKET ENGINES
20090004444 NASA Langley Research Center, Hampton, VA, United States
Towards Verification of Unstructured-Grid Solvers
Thomas, James L.; Diskin, Boris; Rumsey, Christopher L.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489
Copyright; Avail.: CASI: A03, Hardcopy
New methodology for verification of finite-volume computational methods using unstructured grids is presented. The discretization order properties are studied in computational windows, easily constructed within a collection of grids or a single grid. Tests are performed within each window and address a combination of problem-, solution-, and discretization/grid-related features affecting discretization error convergence. The windows can be adjusted to isolate particular elements of the computational scheme, such as the interior discretization, the boundary discretization, or singularities. Studies can use traditional grid-refinement computations within a fixed window or downscaling, a recently-introduced technique in which computations are made within windows contracting toward a focal point of interest. Grids within the windows are constrained to be consistently refined, allowing a meaningful assessment of asymptotic error convergence on unstructured grids. Demonstrations of the method are shown, including a comparative accuracy assessment of commonly-used schemes on general mixed grids and the identification of local accuracy deterioration at boundary intersections. Recommendations to enable attainment of design-order discretization errors for large-scale computational simulations are given.
Author
UNSTRUCTURED GRIDS (MATHEMATICS); FINITE VOLUME METHOD; CONVERGENCE; DETERIORATION
20090004445 NASA Langley Research Center, Hampton, VA, United States
Entry, Descent, and Landing Operations Analysis for the Stardust Entry Capsule
Desai, Prasun N.; Lyons, Dan T.; Tooley, Jeff; Kangas, Julie; [2008]; In English; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004445
On the morning of January 15, 2006, the Stardust capsule successfully landed at the Utah Test and Training range in northwest Utah returning cometary samples from the comet Wild-2. An overview of the entry, descent, and landing (EDL) trajectory analysis that was performed for targeting during the mission operations phase upon final approach to Earth is described. The final orbit determination solution produced an inertial entry flight-path angle of -8.21 deg (the desired nominal value) with a 3-sigma uncertainty of +/-0.0017 deg (2% of the requirement). The navigation and EDL operations effort accurately delivered the entry capsule to the desired landing site. The final landing location was 8.1 km from the target, which was well within the allowable landing area. Overall, the Earth approach operation procedures worked well and there were no issues (logistically or performance based) that arose. As a result, the process of targeting a capsule from an interplanetary trajectory and accurately landing it on Earth was successfully demonstrated.
Author
STARDUST MISSION; DESCENT TRAJECTORIES; FLIGHT PATHS; LANDING SITES; TRAJECTORY ANALYSIS; INTERPLANETARY TRAJECTORIES; ORBIT DETERMINATION
20090004446 NASA Langley Research Center, Hampton, VA, United States
Kinetic Temperature and Carbon Dioxide from Broadband Infrared Limb Emission Measurements Taken from the TIMED/SABER Instrument
Mertens, Christopher J.; Russell III, James M.; Mlynczak, Martin G.; She, Chiao-Yao; Schmidlin, Francis J.; Goldberg, Richard A.; Lopez-Puertas, Manuel; Wintersteiner, Peter P.; Picard, Richard H.; Winick, Jeremy R.; Xu, Xiaojing; [2008]; In English; Original contains color illustrations
Copyright; Avail.: CASI: A03, Hardcopy
The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment is one of four instruments on NASA's Thermosphere-Ionosphere-Energetics and Dynamics (TIMED) satellite. SABER measures broadband infrared limb emission and derives vertical profiles of kinetic temperature (Tk) from the lower stratosphere to approximately 120 km, and vertical profiles of carbon dioxide (CO2) volume mixing ratio (vmr) from approximately 70 km to 120 km. In this paper we report on SABER Tk/CO2 data in the mesosphere and lower thermosphere (MLT) region from the version 1.06 dataset. The continuous SABER measurements provide an excellent dataset to understand the evolution and mechanisms responsible for the global two-level structure of the mesopause altitude. SABER MLT Tk comparisons with ground-based sodium lidar and rocket falling sphere Tk measurements are generally in good agreement. However, SABER CO2 data differs significantly from TIME-GCM model simulations. Indirect CO2 validation through SABER-lidar MLT Tk comparisons and SABER-radiation transfer comparisons of nighttime 4.3 micron limb emission suggest the SABER-derived CO2 data is a better representation of the true atmospheric MLT CO2 abundance compared to model simulations of CO2 vmr.
Author
CARBON DIOXIDE CONCENTRATION; BROADBAND; INFRARED RADIATION; ATMOSPHERIC COMPOSITION; OPTICAL RADAR; RADIATIVE TRANSFER; MIXING RATIOS
20090004448 NASA Langley Research Center, Hampton, VA, United States
Overview of NASA's Integrated Design and Engineering Analysis (IDEA)Environment
Robinson, Jeffrey S.; Martin John G.; December 08, 2008; In English; JANNAF 6th Modeling and Simulation Subcommittee Meeting, 8-12 Dec. 2008, Orlando, FL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 599489.02.07.07.09
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004448
Historically, the design of subsonic and supersonic aircraft has been divided into separate technical disciplines (such as propulsion, aerodynamics and structures) each of which performs their design and analysis in relative isolation from others. This is possible in most cases either because the amount of interdisciplinary coupling is minimal or because the interactions can be treated as linear. The design of hypersonic airbreathing vehicles, like NASA s X-43, is quite the opposite. Such systems are dominated by strong non-linear interactions between disciplines. The design of these systems demands that a multi-disciplinary approach be taken. Furthermore, increased analytical fidelity at the conceptual design phase is highly desirable as many of the non-linearities are not captured by lower fidelity tools. Only when these systems are designed from a true multi-disciplinary perspective can the real performance benefits be achieved and complete vehicle systems be fielded. Toward this end, the Vehicle Analysis Branch at NASA Langley Research Center has been developing the Integrated Design & Engineering Analysis (IDEA) Environment. IDEA is a collaborative environment for parametrically modeling conceptual and preliminary launch vehicle configurations using the Adaptive Modeling Language (AML) as the underlying framework. The environment integrates geometry, configuration, propulsion, aerodynamics, aerothermodynamics, trajectory, closure and structural analysis into a generative, parametric, unified computational model where data is shared seamlessly between the different disciplines. Plans are also in place to incorporate life cycle analysis tools into the environment which will estimate vehicle operability, reliability and cost. IDEA is currently being funded by NASA s Hypersonics Project, a part of the Fundamental Aeronautics Program within the Aeronautics Research Mission Directorate. The environment is currently focused around a two-stage-to-orbit configuration with a turbine based combined cycle (TBCC) first stage and reusable rocket second stage. This paper provides an overview of the development of the IDEA environment, a description of the current status and detail of future plans.
Author
AERODYNAMIC CONFIGURATIONS; LAUNCH VEHICLE CONFIGURATIONS; DESIGN ANALYSIS; STRUCTURAL ANALYSIS; TRAJECTORY ANALYSIS; HYPERSONIC VEHICLES; AEROTHERMODYNAMICS
20090004463 NASA Marshall Space Flight Center, Huntsville, AL, United States
The NASA MSFC Earth Global Reference Atmospheric Model-2007 Version
Leslie, F.W.; Justus, C.G.; November 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNM04AA02C
Report No.(s): NASA/TM--2008-215581; M-1246; Copyright; Avail.: CASI: A06, Hardcopy
Reference or standard atmospheric models have long been used for design and mission planning of various aerospace systems. The NASA/Marshall Space Flight Center (MSFC) Global Reference Atmospheric Model (GRAM) was developed in response to the need for a design reference atmosphere that provides complete global geographical variability, and complete altitude coverage (surface to orbital altitudes) as well as complete seasonal and monthly variability of the thermodynamic variables and wind components. A unique feature of GRAM is that, addition to providing the geographical, height, and monthly variation of the mean atmospheric state, it includes the ability to simulate spatial and temporal perturbations in these atmospheric parameters (e.g. fluctuations due to turbulence and other atmospheric perturbation phenomena). A summary comparing GRAM features to characteristics and features of other reference or standard atmospheric models, can be found Guide to Reference and Standard Atmosphere Models. The original GRAM has undergone a series of improvements over the years with recent additions and changes. The software program is called Earth-GRAM2007 to distinguish it from similar programs for other bodies (e.g. Mars, Venus, Neptune, and Titan). However, in order to make this Technical Memorandum (TM) more readable, the software will be referred to simply as GRAM07 or GRAM unless additional clarity is needed. Section 1 provides an overview of the basic features of GRAM07 including the newly added features. Section 2 provides a more detailed description of GRAM07 and how the model output generated. Section 3 presents sample results. Appendices A and B describe the Global Upper Air Climatic Atlas (GUACA) data and the Global Gridded Air Statistics (GGUAS) database. Appendix C provides instructions for compiling and running GRAM07. Appendix D gives a description of the required NAMELIST format input. Appendix E gives sample output. Appendix F provides a list of available parameters to enable the user to generate special output. Appendix G gives an example and guidance on incorporating GRAM07 as a subroutine in other programs such as trajectory codes or orbital propagation routines.
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ATMOSPHERIC MODELS; MISSION PLANNING; NASA SPACE PROGRAMS; EARTH SCIENCES; AEROSPACE SYSTEMS; GEOPHYSICS; CLIMATOLOGY
Additions to the NASA Aeronautics and Space Database as of 02/03/2009
20090004512 NASA Marshall Space Flight Center, Huntsville, AL, United States
NASA Ares I Crew Launch Vehicle Upper Stage Overview
Davusm Daniel J.; McArthur, J. Craig; July 20, 2008; In English; 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 20-23 Jul. 2008, Hartford,CT, United States; Original contains color illustrations
Report No.(s): MSFC-1038; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004512
By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA's Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program's transportation system.
Author
CONSTELLATION PROGRAM; UPPER STAGE ROCKET ENGINES; SPACECRAFT CONFIGURATIONS; ARES 1 UPPER STAGE
20090004513 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Optical Images of an Exosolar Planet 25 Light Years from Earth
Kalas, Paul; Graham, James R.; Chiang, Eugene; Fitzgerald, Michael P.; Clampin, Mark; Kite, Edwin S.; Stapelfeldt, Karl; Marois, Christian; Krist, John; November 19, 2008; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Fomalhaut is a bright star 7.7 parsecs (25 light years) from Earth that harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. In the plane of the belt, Fomalhaut b lies approximately 119 astronomical units (AU) from the star and 18 AU from the dust belt, matching predictions. We detect counterclockwise orbital motion using Hubble Space Telescope observations separated by 1.73 years. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter for the belt to avoid gravitational disruption. The flux detected at 0.8 m is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 0.6 micron and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observed variability of unknown origin at 0.6 micron.
Author
EXTRASOLAR PLANETS; VISUAL OBSERVATION; GAS GIANT PLANETS; PLANET DETECTION
20090004546 NASA Glenn Research Center, Cleveland, OH, United States
Flow Control Opportunities for Propulsion Systems
Cutley, Dennis E.; June 23, 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.21.03
Report No.(s): E-16831; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004546
The advancement of technology in gas turbine engines used for aerospace propulsion has been focused on achieving significant performance improvements. At the system level, these improvements are expressed in metrics such as engine thrust-to-weight ratio and system and component efficiencies. The overall goals are directed at reducing engine weight, fuel burn, emissions, and noise. At a component level, these goals translate into aggressive designs of each engine component well beyond the state of the art.
Author
THRUST-WEIGHT RATIO; PROPULSION SYSTEM PERFORMANCE; EXHAUST EMISSION; WEIGHT REDUCTION; GAS TURBINE ENGINES; COMBUSTION PRODUCTS
20090004550 NASA Glenn Research Center, Cleveland, OH, United States
Lunar Dust 101
Gaier, James R.; November 18, 2008; In English; Lunar Dust Filtration and Separations Workshop, 18-20 Nov. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS WBS 936374.03.03.03
Report No.(s): E-16837; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004550
Largely due to rock and soil samples returned during the Apollo program, much has been learned about the composition and properties of lunar regolith. Although, for the most part, the mineral composition resembles terrestrial minerals, the characteristics of the lunar environment have led to very different weathering processes. These result in substantial differences in the particle shapes, particle size distributions, and surface chemistry. These differences lead to non-intuitive adhesion, abrasion, and possible health properties that will pose challenges to future lunar missions. An overview of lunar dust composition and properties will be given with a particular emphasis on possible health effects.
Author
LUNAR DUST; SOIL SAMPLING; LUNAR ROCKS; SIZE DISTRIBUTION; SURFACE REACTIONS; WEATHERING; HEALTH
20090004551 NASA Glenn Research Center, Cleveland, OH, United States
Adsorption of Water on JSC-1A Lunar Simulant Samples
Goering, John; Sah, Shweta; Burghaus, Uwe; Street, Kenneth W.; October 09, 2008; In English; Geological Society of America Meeting, 9 Oct. 2008, Houston, TX, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 936374.03.03.03
Report No.(s): E-16838; Copyright; Avail.: CASI: A03, Hardcopy
Remote sensing probes sent to the moon in the 1990s indicated that water may exist in areas such as the bottoms of deep, permanently shadowed craters at the lunar poles, buried under regolith. Water is of paramount importance for any lunar exploration and colonization project which would require self-sustainable systems. Therefore, investigating the interaction of water with lunar regolith is pertinent to future exploration. The lunar environment can be approximated in ultra-high vacuum systems such as those used in thermal desorption spectroscopy (TDS). Questions about water dissociation, surface wetting, degree of crystallization, details of water-ice transitions, and cluster formation kinetics can be addressed by TDS. Lunar regolith specimens collected during the Apollo missions are still available though precious, so testing with simulant is required before applying to use lunar regolith samples. Hence, we used for these studies JSC-1a, mostly an aluminosilicate glass and basaltic material containing substantial amounts of plagioclase, some olivine and traces of other minerals. Objectives of this project include: 1) Manufacturing samples using as little raw material as possible, allowing the use of surface chemistry and kinetics tools to determine the feasibility of parallel studies on regolith, and 2) Characterizing the adsorption kinetics of water on the regolith simulant. This has implications for the probability of finding water on the moon and, if present, for recovery techniques. For condensed water films, complex TDS data were obtained containing multiple features, which are related to subtle rearrangements of the water adlayer. Results from JSC-1a TDS studies indicate: 1) Water dissociation on JSC-1a at low exposures, with features detected at temperatures as high as 450 K and 2) The formation of 3D water clusters and a rather porous condensed water film. It appears plausible that the sub- m sized particles act as nucleation centers.
Author
ADSORPTION; REMOTE SENSING; LUNAR ENVIRONMENT; LUNAR SOIL; SURFACE WATER; LUNAR ROCKS; OLIVINE; SURFACE REACTIONS; REGOLITH
20090004555 NASA Glenn Research Center, Cleveland, OH, United States
Gear Windage Modeling Progress - Experimental Validation Status
Kunz, Rob; Handschuh, Robert F.; October 07, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01
Report No.(s): E-16839; Copyright; Avail.: CASI: A03, Hardcopy
In the Subsonics Rotary Wing (SRW) Project being funded for propulsion work at NASA Glenn Research Center, performance of the propulsion system is of high importance. In current rotorcraft drive systems many gearing components operate at high rotational speed (pitch line velocity > 24000 ft/ min). In our testing of high speed helical gear trains at NASA Glenn we have found that the work done on the air - oil mist within the gearbox can become a significant part of the power loss of the system. This loss mechanism is referred to as windage. The effort described in this presentation is to try to understand the variables that affect windage, develop a good experimental data base to validate, the analytical project being conducted at Penn State University by Dr. Rob Kunz under a NASA SRW NRA. The presentation provides an update to the status of these efforts.
Author
MECHANICAL DRIVES; TRANSMISSIONS (MACHINE ELEMENTS); ROTARY WING AIRCRAFT; HIGH SPEED
20090004557 NASA Langley Research Center, Hampton, VA, United States
Aerothermodynamic Testing and Boundary Layer Trip Sizing of the HIFiRE Flight 1 Vehicle
Berger, Karen T.; Greene, Frank A.; Kimmel, Roger; Alba, Christopher; Johnson, Heath; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 526282.01.07.04.05
Copyright; Avail.: CASI: A03, Hardcopy
An experimental wind tunnel test was conducted in the NASA Langley Research Center s 20-Inch Mach 6 Air Tunnel in support of the Hypersonic International Flight Research Experimentation Program. The information in this article is focused on the Flight 1 configuration, the first in a series of flight experiments. The article documents experimental measurements made over a Reynolds numbers range of 2.1x10(exp 6)/ft to 5.6x10(exp 6)/ft and angles of attack of -5 to +5 deg on several scaled ceramic heat transfer models of the Flight 1 configuration. Global heat transfer was measured using phosphor thermography and the resulting images and heat transfer distributions were used to infer the state of the boundary layer on the vehicle windside and leeside surfaces. Boundary layer trips were used to force the boundary layer turbulent and the experimental data highlighted in this article were used to size and place the boundary layer trip for the flight vehicle. The required height of the flight boundary layer trip was determined to be 0.079 in and the trip was moved from the design location of 7.87 in to 20.47 in to ensure that augmented heating would not impact the laminar side of the vehicle. Allowable roughness was selected to be 3.2x10(exp -3) in.
Author
WIND TUNNEL TESTS; AEROTHERMODYNAMICS; BOUNDARY LAYER CONTROL; REYNOLDS NUMBER; SURFACE ROUGHNESS; TURBULENCE; ANGLE OF ATTACK; BOUNDARY LAYERS
20090004558 NASA Langley Research Center, Hampton, VA, United States
Evaluation of Acoustic Emission NDE of Kevlar Composite Over Wrapped Pressure Vessels
Horne, Michael R.; Madaras, Eric I.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 939904.05.07
Report No.(s): NASA/TM-2008-215558; L-19534; Copyright; Avail.: CASI: A03, Hardcopy
Pressurization and failure tests of small Kevlar/epoxy COPV bottles were conducted during 2006 and 2007 by Texas Research Institute Austin, Inc., at TRI facilities. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. Results of some of the tests indicate a possibility that AE can be used to track the stress-rupture degradation of COPV vessels.
Author
PRESSURE VESSELS; KEVLAR (TRADEMARK); EPOXY RESINS; ACOUSTIC EMISSION; DEGRADATION
Additions to the NASA Aeronautics and Space Database as of 02/04/2009
20090004576 NASA Glenn Research Center, Cleveland, OH, United States
Oxidation of Carbon/Carbon through Coating Cracks
Jacobson, N. S.; Roth, d. J.; Rauser, R. W.; Cawley, J. D.; Curry, D. M.; October 12, 2008; In English; 214th Meeting of the Electrochemical Society, 12-17 Oct. 2008, Honolulu, HI, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 377816.06.03.02.08
Report No.(s): E-16840; Copyright; Avail.: CASI: A03, Hardcopy
Reinforced carbon/carbon (RCC) is used to protect the wing leading edge and nose cap of the Space Shuttle Orbiter on re-entry. It is composed of a lay-up of carbon/carbon fabric protected by a SiC conversion coating. Due to the thermal expansion mismatch of the carbon/carbon and the SiC, the SiC cracks on cool-down from the processing temperature. The cracks act as pathways for oxidation of the carbon/carbon. A model for the diffusion controlled oxidation of carbon/carbon through machined slots and cracks is developed and compared to laboratory experiments. A symmetric cylindrical oxidation cavity develops under the slots, confirming diffusion control. Comparison of cross sectional dimensions as a function of oxidation time shows good agreement with the model. A second set of oxidation experiments was done with samples with only the natural craze cracks, using weight loss as an index of oxidation. The agreement of these rates with the model is quite reasonab
Author
CARBON-CARBON COMPOSITES; OXIDATION; SURFACE CRACKS; COATING; THERMAL EXPANSION; SILICON CARBIDES
20090004577 NASA Glenn Research Center, Cleveland, OH, United States
Solar Power System Design for the Solar Probe+ Mission
Landis, Geoffrey A.; Schmitz, Paul C.; Kinnison, James; Fraeman, Martin; Roufberg, Lew; Vernon, Steve; Wirzburger, Melissa; July 28, 2008; In English; 6th International Energy Conversion Engineering Conference (IECEC), 28-30 Jul. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 937818.01.01.10
Report No.(s): AIAA Paper-2008-5712; E-16841; Copyright; Avail.: CASI: A02, Hardcopy
Solar Probe+ is an ambitious mission proposed to the solar corona, designed to make a perihelion approach of 9 solar radii from the surface of the sun. The high temperature, high solar flux environment makes this mission a significant challenge for power system design. This paper summarizes the power system conceptual design for the solar probe mission. Power supplies considered included nuclear, solar thermoelectric generation, solar dynamic generation using Stirling engines, and solar photovoltaic generation. The solar probe mission ranges from a starting distance from the sun of 1 AU, to a minimum distance of about 9.5 solar radii, or 0.044 AU, from the center of the sun. During the mission, the solar intensity ranges from one to about 510 times AM0. This requires power systems that can operate over nearly three orders of magnitude of incident intensity.
Author
SOLAR PROBES; SOLAR CORONA; SYSTEMS ENGINEERING; HIGH TEMPERATURE; SOLAR FLUX
20090004578 NASA Glenn Research Center, Cleveland, OH, United States
Solar Power for Near Sun, High-Temperature Missions
Landis, Geoffrey A.; May 11, 2008; In English; 33rd IEEE Photovoltaics Specialists Conference, 11-16 May 2008, San Diego, CA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 937818.01.01.10
Report No.(s): E-16842; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004578
Existing solar cells lose performance at the high temperatures encountered in Mercury orbit and inward toward the sun. For future missions designed to probe environments close to the sun, it is desirable to develop array technologies for high temperature and high light intensity. Approaches to solar array design for near-sun missions include modifying the terms governing temperature of the cell and the efficiency at elevated temperature, or use of techniques to reduce the incident solar energy to limit operating temperature. An additional problem is found in missions that involve a range of intensities, such as the Solar Probe + mission, which ranges from a starting distance of 1 AU from the sun to a minimum distance of 9.5 solar radii, or 0.044 AU. During the mission, the solar intensity ranges from one to about 500 times AM0. This requires a power system to operate over nearly three orders of magnitude of incident intensity.
Author
SOLAR ARRAYS; OPERATING TEMPERATURE; PLANETARY ORBITS; SOLAR ENERGY; HIGH TEMPERATURE; SUN; SOLAR CELLS
20090004579 NASA Glenn Research Center, Cleveland, OH, United States
Forecasting Proximal Femur and Wrist Fracture Caused by a Fall to the Side during Space Exploration Missions to the Moon and Mars
Lewandowski, Beth E.; Myers, Jerry G.; Sulkowski, C.; Ruehl, K.; Licata, A.; September 29, 2008; In English; 59th International Astronautical Congress 2008, 29 Sep. - 3 Oct. 2008, Glasgow, Scotland, United Kingdom; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 444543.01.02.01
Report No.(s): Paper ID 1494; E_16843; Copyright; Avail.: CASI: A03, Hardcopy
The possibility of bone fracture in space is a concern due to the negative impact it could have on a mission. The Bone Fracture Risk Module (BFxRM) developed at the NASA Glenn Research Center is a statistical simulation that quantifies the probability of bone fracture at specific skeletal locations for particular activities or events during space exploration missions. This paper reports fracture probability predictions for the proximal femur and wrist resulting from a fall to the side during an extravehicular activity (EVA) on specific days of lunar and Martian exploration missions. The risk of fracture at the proximal femur on any given day of the mission is small and fairly constant, although it is slightly greater towards the end of the mission, due to a reduction in proximal femur bone mineral density (BMD). The risk of wrist fracture is greater than the risk of hip fracture and there is an increased risk on Mars since it has a higher gravitational environment than the moon. The BFxRM can be used to help manage the risk of bone fracture in space as an engineering tool that is used during mission operation and resource planning.
Author
BONES; MUSCULOSKELETAL SYSTEM; BONE MINERAL CONTENT; FEMUR; EXTRAVEHICULAR ACTIVITY; FRACTURING; WRIST
20090004580 NASA Glenn Research Center, Cleveland, OH, United States
Effect of Microscopic Damage Events on Static and Ballistic Impact Strength of Triaxial Braid Composites
Littell, Justin D.; Binienda, Wieslaw K.; Arnold, William A.; Roberts, Gary d.; Goldberg, Robert K.; October 20, 2008; In English; 4th International Confrence on Composites Testing and Model Identification, 20-22 Oct. 2008, Dayton, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 698259.02.07.03.04.01
Report No.(s): E-16844; Copyright; Avail.: CASI: A03, Hardcopy
In previous work, the ballistic impact resistance of triaxial braided carbon/epoxy composites made with large flat tows (12k and 24k) was examined by impacting 2 X2 X0.125" composite panels with gelatin projectiles. Several high strength, intermediate modulus carbon fibers were used in combination with both untoughened and toughened matrix materials. A wide range of penetration thresholds were measured for the various fiber/matrix combinations. However, there was no clear relationship between the penetration threshold and the properties of the constituents. During some of these experiments high speed cameras were used to view the failure process, and full-field strain measurements were made to determine the strain at the onset of failure. However, these experiments provided only limited insight into the microscopic failure processes responsible for the wide range of impact resistance observed. In order to investigate potential microscopic failure processes in more detail, quasi-static tests were performed in tension, compression, and shear. Full-field strain measurement techniques were used to identify local regions of high strain resulting from microscopic failures. Microscopic failure events near the specimen surface, such as splitting of fiber bundles in surface plies, were easily identified. Subsurface damage, such as fiber fracture or fiber bundle splitting, could be identified by its effect on in-plane surface strains. Subsurface delamination could be detected as an out-of-plane deflection at the surface. Using this data, failure criteria could be established at the fiber tow level for use in analysis. An analytical formulation was developed to allow the microscopic failure criteria to be used in place of macroscopic properties as input to simulations performed using the commercial explicit finite element code, LS-DYNA. The test methods developed to investigate microscopic failure will be presented along with methods for determining local failure criteria that can be used in analysis. Results of simulations performed using LS-DYNA will be presented to illustrate the capabilities and limitations for simulating failure during quasi-static deformation and during ballistic impact of large unit cell size triaxial braid composites.
Author
BRAIDED COMPOSITES; COMPOSITE STRUCTURES; CARBON FIBERS; EPOXY MATRIX COMPOSITES; STATIC DEFORMATION; DELAMINATING; IMPACT STRENGTH; MATRIX MATERIALS
20090004581 NASA Glenn Research Center, Cleveland, OH, United States
Evaluation of COTS Electronic Parts for Extreme Temperature Use in NASA Missions
Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik; July 28, 2008; In English; International Energy Conversion Engineering Conference (IECEC), 28-30 Jul. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07B
Report No.(s): E-16849; AIAA Paper 2008-5650; Copyright; Avail.: CASI: A02, Hardcopy
Electronic systems capable of extreme temperature operation are required for many future NASA space exploration missions where it is desirable to have smaller, lighter, and less expensive spacecraft and probes. Presently, spacecraft on-board electronics are maintained at about room temperature by use of thermal control systems. An Extreme Temperature Electronics Program at the NASA Glenn Research Center focuses on development of electronics suitable for space exploration missions. The effects of exposure to extreme temperatures and thermal cycling are being investigated for commercial-off-the-shelf components as well as for components specially developed for harsh environments. An overview of this program along with selected data is presented.
Author
COMMERCIAL OFF-THE-SHELF PRODUCTS; TEMPERATURE EFFECTS; ELECTRONICS; THERMAL CYCLING TESTS; SPACE EXPLORATION; TEMPERATURE CONTROL
20090004582 NASA Glenn Research Center, Cleveland, OH, United States
Silicon-On-Insulator (SOI) Devices and Mixed-Signal Circuits for Extreme Temperature Applications
Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik; June 15, 2008; In English; 39th IEEE Power Electronics Specialists Conference, 15-19 Jun. 2008, Rhodes, Greece; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 939904.01.03.02.01
Report No.(s): E-16850; Copyright; Avail.: CASI: A02, Hardcopy
Electronic systems in planetary exploration missions and in aerospace applications are expected to encounter extreme temperatures and wide thermal swings in their operational environments. Electronics designed for such applications must, therefore, be able to withstand exposure to extreme temperatures and to perform properly for the duration of the missions. Electronic parts based on silicon-on-insulator (SOI) technology are known, based on device structure, to provide faster switching, consume less power, and offer better radiation-tolerance compared to their silicon counterparts. They also exhibit reduced current leakage and are often tailored for high temperature operation. However, little is known about their performance at low temperature. The performance of several SOI devices and mixed-signal circuits was determined under extreme temperatures, cold-restart, and thermal cycling. The investigations were carried out to establish a baseline on the functionality and to determine suitability of these devices for use in space exploration missions under extreme temperatures. The experimental results obtained on selected SOI devices are presented and discussed in this paper.
Author
SOI (SEMICONDUCTORS); TEMPERATURE EFFECTS; THERMAL CYCLING TESTS; RADIATION TOLERANCE; HIGH TEMPERATURE; AEROSPACE ENGINEERING
20090004613 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Analyzing the Core Flight Software (CFS) with SAVE
Ganesan, Dharmalingam; Lindvall, Mikael; McComas, David; November 13, 2008; In English; Flight Software Workshop 2008 (FSW-08), 13-14 Nov. 2008, Laurel, MD, United States; Original contains color illustrations
Contract(s)/Grant(s): NNG05GE77G
Copyright; Avail.: CASI: A03, Hardcopy
This viewgraph presentation describes the SAVE tool and it's application to Core Flight Software (CFS). The contents include: 1) Fraunhofer-a short intro; 2) Context of this Collaboration; 3) CFS-Core Flight Software?; 4) The SAVE Tool; 5) Applying SAVE to CFS -A few example analyses; and 6) Goals.
CASI
SOFTWARE ENGINEERING; COMPUTER SYSTEMS DESIGN; APPLICATION PROGRAMMING INTERFACE; ARCHITECTURE (COMPUTERS); SYSTEMS INTEGRATION
20090004620 NASA Marshall Space Flight Center, Huntsville, AL, United States
Lessons in Systems Engineering: The SSME Weight Growth History
Ryan, Richard; August 21, 2008; In English; NASA APPL JSC Center forum on Systems Engineering, 21 Aug. 2008, Houston, TX, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004620
This viewgraph presentation describes the Space Shuttle Main Engine (SSME) weight growth history and lessons learned from SSME weight imbalances.
CASI
LESSONS LEARNED; SPACE SHUTTLE MAIN ENGINE; SYSTEMS ENGINEERING; ROCKET ENGINE DESIGN; WEIGHT ANALYSIS
Additions to the NASA Aeronautics and Space Database as of 02/05/2009
20090004672 NASA Glenn Research Center, Cleveland, OH, United States
Thermoelectric Properties of Self Assembled TiO2/SnO2 Nanocomposites
Dynys, Fred; Sayir, Ali; Sehirlioglu, Alp; May 26, 2008; In English; European Materials Resource Society Conference, 26-30 May 2008, Strasbourg, France; Original contains color illustrations
Contract(s)/Grant(s): WBS 138494.04.02.01
Report No.(s): E-16834; Copyright; Avail.: CASI: A03, Hardcopy
Recent advances in improving efficiency of thermoelectric materials are linked to nanotechnology. Thermodynamically driven spinodal decomposition was utilized to synthesize bulk nanocomposites. TiO2/SnO2 system exhibits a large spinodal region, ranging from 15 to 85 mole % TiO2. The phase separated microstructures are stable up to 1400 C. Semiconducting TiO2/SnO2 powders were synthesized by solid state reaction between TiO2 and SnO2. High density samples were fabricated by pressureless sintering. Self assemble nanocomposites were achieved by annealing at 1000 to 1350 C. X-ray diffraction reveal phase separation of (Ti(x)Sn(1-x))O2 type phases. The TiO2/SnO2 nanocomposites exhibit n-type behavior; a power factor of 70 W/mK2 at 1000 C has been achieved with penta-valent doping. Seebeck, thermal conductivity, electrical resistivity and microstructure will be discussed in relation to composition and doping.
Author
NANOCOMPOSITES; THERMOELECTRICITY; X RAY DIFFRACTION; ANNEALING; MICROSTRUCTURE; NANOTECHNOLOGY; POWDER (PARTICLES); THERMAL CONDUCTIVITY; TITANIUM OXIDES
20090004673 NASA Glenn Research Center, Cleveland, OH, United States
Performance of the THS4302 and the Class V Radiation-Tolerant THS4304-SP Silicon Germanium Wideband Amplifiers at Extreme Temperatures
Patterson, Richard L.; Elbuluk, Malik; Hammoud, Ahmad; VanKeuls, Frederick W.; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07BWBS 939904.11.03.01
Copyright; Avail.: CASI: A01, Hardcopy
This report discusses the performance of silicon germanium, wideband gain amplifiers under extreme temperatures. The investigated devices include Texas Instruments THS4304-SP and THS4302 amplifiers. Both chips are manufactured using the BiCom3 process based on silicon germanium technology along with silicon-on-insulator (SOI) buried oxide layers. The THS4304-SP device was chosen because it is a Class V radiation-tolerant (150 kRad, TID silicon), voltage-feedback operational amplifier designed for use in high-speed analog signal applications and is very desirable for NASA missions. It operates with a single 5 V power supply [1]. It comes in a 10-pin ceramic flatpack package, and it provides balanced inputs, low offset voltage and offset current, and high common mode rejection ratio. The fixed-gain THS4302 chip, which comes in a 16-pin leadless package, offers high bandwidth, high slew rate, low noise, and low distortion [2]. Such features have made the amplifier useful in a number of applications such as wideband signal processing, wireless transceivers, intermediate frequency (IF) amplifier, analog-to-digital converter (ADC) preamplifier, digital-to-analog converter (DAC) output buffer, measurement instrumentation, and medical and industrial imaging.
Author
ANALOG TO DIGITAL CONVERTERS; SOI (SEMICONDUCTORS); SILICON; GERMANIUM; TEMPERATURE EFFECTS; FEEDBACK AMPLIFIERS; LOW NOISE; TRANSMITTER RECEIVERS; OPERATIONAL AMPLIFIERS
20090004674 NASA Glenn Research Center, Cleveland, OH, United States
Performance of High Temperature Operational Amplifier, Type LM2904WH, under Extreme Temperatures
Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07BWBS 939904.11.03.01
Report No.(s): E-16846; Copyright; Avail.: CASI: A01, Hardcopy
Operation of electronic parts and circuits under extreme temperatures is anticipated in NASA space exploration missions as well as terrestrial applications. Exposure of electronics to extreme temperatures and wide-range thermal swings greatly affects their performance via induced changes in the semiconductor material properties, packaging and interconnects, or due to incompatibility issues between interfaces that result from thermal expansion/contraction mismatch. Electronics that are designed to withstand operation and perform efficiently in extreme temperatures would mitigate risks for failure due to thermal stresses and, therefore, improve system reliability. In addition, they contribute to reducing system size and weight, simplifying its design, and reducing development cost through the elimination of otherwise required thermal control elements for proper ambient operation. A large DC voltage gain (100 dB) operational amplifier with a maximum junction temperature of 150 C was recently introduced by STMicroelectronics [1]. This LM2904WH chip comes in a plastic package and is designed specifically for automotive and industrial control systems. It operates from a single power supply over a wide range of voltages, and it consists of two independent, high gain, internally frequency compensated operational amplifiers. Table I shows some of the device manufacturer s specifications.
Author
HIGH TEMPERATURE; TEMPERATURE EFFECTS; OPERATIONAL AMPLIFIERS; SEMICONDUCTORS (MATERIALS); THERMAL STRESSES; CIRCUITS; CHIPS; ELECTRIC POTENTIAL; TEMPERATURE CONTROL
20090004675 NASA Glenn Research Center, Cleveland, OH, United States
Performance of MEMS Silicon Oscillator, ASFLM1, under Wide Operating Temperature Range
Patterson, Richard L.; Hammoud, Ahmad; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07BWBS 939904.11.03.01
Report No.(s): E-16847; Copyright; Avail.: CASI: A02, Hardcopy
Over the last few years, MEMS (Micro-Electro-Mechanical Systems) resonator-based oscillators began to be offered as commercial-off-the-shelf (COTS) parts by a few companies [1-2]. These quartz-free, miniature silicon devices could compete with the traditional crystal oscillators in providing the timing (clock function) for many digital and analog electronic circuits. They provide stable output frequency, offer great tolerance to shock and vibration, and are immune to electro-static discharge [1-2]. In addition, they are encapsulated in compact lead-free packages, cover a wide frequency range (1 MHz to 125 MHz), and are specified, depending on the grade, for extended temperature operation from -40 C to +85 C. The small size of the MEMS oscillators along with their reliability and thermal stability make them candidates for use in space exploration missions. Limited data, however, exist on the performance and reliability of these devices under operation in applications where extreme temperatures or thermal cycling swings, which are typical of space missions, are encountered. This report presents the results of the work obtained on the evaluation of an ABRACON Corporation MEMS silicon oscillator chip, type ASFLM1, under extreme temperatures.
Author
DIGITAL ELECTRONICS; THERMAL CYCLING TESTS; MICROELECTROMECHANICAL SYSTEMS; OSCILLATORS; ANALOG CIRCUITS; COMMERCIAL OFF-THE-SHELF PRODUCTS; SILICON
20090004676 NASA Glenn Research Center, Cleveland, OH, United States
Extreme High and Low Temperature Operation of the Silicon-On-Insulator Type CHT-OPA Operational Amplifier
Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik; January 11, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNC06BA07BWBS 939904.01.03.02.01
Report No.(s): E-16848; Copyright; Avail.: CASI: A02, Hardcopy
A new operational amplifier chip based on silicon-on-insulator technology was evaluated for potential use in extreme temperature environments. The CHT-OPA device is a low power, precision operational amplifier with rail-to-rail output swing capability, and it is rated for operation between -55 C and +225 C. A unity gain inverting circuit was constructed utilizing the CHT-OPA chip and a few passive components. The circuit was evaluated in the temperature range from -190 C to +200 C in terms of signal gain and phase shift, and supply current. The investigations were carried out to determine suitability of this device for use in space exploration missions and aeronautic applications under wide temperature incursion. Re-restart capability at extreme temperatures, i.e. power switched on while the device was soaked at extreme temperatures, was also investigated. In addition, the effects of thermal cycling under a wide temperature range on the operation of this high performance amplifier were determined. The results from this work indicate that this silicon-on-insulator amplifier chip maintained very good operation between +200 C and -190 C. The limited thermal cycling had no effect on the performance of the amplifier, and it was able to re-start at both -190 C and +200 C. In addition, no physical degradation or packaging damage was introduced due to either extreme temperature exposure or thermal cycling. The good performance demonstrated by this silicon-on-insulator operational amplifier renders it a potential candidate for use in space exploration missions or other environments under extreme temperatures. Additional and more comprehensive characterization is, however, required to establish the reliability and suitability of such devices for long term use in extreme temperature applications.
Author
HIGH TEMPERATURE; LOW TEMPERATURE; OPERATIONAL AMPLIFIERS; SOI (SEMICONDUCTORS); TECHNOLOGY UTILIZATION
20090004677 NASA Glenn Research Center, Cleveland, OH, United States
Electronic Components for use in Extreme Temperature Aerospace Applications
Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik; February 11, 2008; In English; 12th International Components for Military and Space Electronics Conference (CMSE 08), 11-14 Feb. 2008, San Diego, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 939904.01.03.02.01
Report No.(s): E-16851; Copyright; Avail.: CASI: A03, Hardcopy
Electrical power management and control systems designed for use in planetary exploration missions and deep space probes require electronics that are capable of efficient and reliable operation under extreme temperature conditions. Space-based infra-red satellites, all-electric ships, jet engines, electromagnetic launchers, magnetic levitation transport systems, and power facilities are also typical examples where the electronics are expected to be exposed to harsh temperatures and to operate under severe thermal swings. Most commercial-off-the-shelf (COTS) devices are not designed to function under such extreme conditions and, therefore, new parts must be developed or the conventional devices need to be modified. For example, spacecraft operating in the cold environment of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. At the other end, built-in radiators and coolers render the operation of electronics possible under hot conditions. These thermal measures lead to design complexity, affect development costs, and increase size and weight. Electronics capable of operation at extreme temperatures, thus, will not only tolerate the hostile operational environment, but also make the overall system efficient, more reliable, and less expensive. The Extreme Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electronics suitable for applications in the aerospace environment and deep space exploration missions. Research is being conducted on devices, including COTS parts, for potential use under extreme temperatures. These components include semiconductor switching devices, passive devices, DC/DC converters, operational amplifiers, and oscillators. An overview of the program will be presented along with some experimental findings.
Author
AEROSPACE ENGINEERING; AEROSPACE ENVIRONMENTS; ELECTRONIC EQUIPMENT; TEMPERATURE EFFECTS; THERMAL STRESSES; EXTRATERRESTRIAL ENVIRONMENTS; SPACECRAFT ELECTRONIC EQUIPMENT
20090004679 NASA Glenn Research Center, Cleveland, OH, United States
Progress Towards III-V Photovoltaics on Flexible Substrates
McNatt, Jeremiah S.; Pal, AnnaMaria T.; Clark, Eric B.; Sayir, Ali; Raffaelle, Ryne P.; Bailey, Christopher G.; Hubbard, Seth M.; Maurer, William F.; Fritzemeier, Les; July 28, 2008; In English; 6th International Energy Conversion Engineering Conference (IECEC), 28-30 Jul. 2008, Cleveland, OH, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 698671.01.03.54
Report No.(s): E-16853; Copyright; Avail.: CASI: A01, Hardcopy
Presented here is the recent progress of the NASA Glenn Research Center OMVPE group's efforts in the development of high efficiency thin-film polycrystalline III-V photovoltaics on optimum substrates. By using bulk polycrystalline germanium (Ge) films, devices of high efficiency and low mass will be developed and incorporated onto low-cost flexible substrates. Our progress towards the integration of high efficiency polycrystalline III-V devices and recrystallized Ge films on thin metal foils is discussed.
Author
PHOTOVOLTAIC CONVERSION; VAPOR PHASE EPITAXY; RECRYSTALLIZATION; POLYCRYSTALS; METAL FOILS; GERMANIUM; ORGANOMETALLIC COMPOUNDS
20090004682 NASA Glenn Research Center, Cleveland, OH, United States
Precipitation Model Validation in 3rd Generation Aeroturbine Disc Alloys
Olson, G. B.; Jou, H.-J.; Jung, J.; Sebastian, J. T.; Misra, A.; Locci, I.; Hull, D.; Septembert 14, 2008; In English; 11th International Superalloys 2008, 14-18 Sep. 2008, Champion, PAu1, FROM; Original contains black and white illustrations
Contract(s)/Grant(s): NNC07CB01CWBS 698259.02.07.03
Report No.(s): E-16858; Copyright; Avail.: CASI: A02, Hardcopy
In support of application of the DARPA-AIM methodology to the accelerated hybrid thermal process optimization of 3rd generation aeroturbine disc alloys with quantified uncertainty, equilibrium and diffusion couple experiments have identified available fundamental thermodynamic and mobility databases of sufficient accuracy. Using coherent interfacial energies quantified by Single-Sensor DTA nucleation undercooling measurements, PrecipiCalc(TM) simulations of nonisothermal precipitation in both supersolvus and subsolvus treated samples show good agreement with measured gamma particle sizes and compositions. Observed longterm isothermal coarsening behavior defines requirements for further refinement of elastic misfit energy and treatment of the parallel evolution of incoherent precipitation at grain boundaries.
Author
MATHEMATICAL MODELS; NUCLEATION; SUPERCOOLING; TURBINES; PRECIPITATION MEASUREMENT; NICKEL ALLOYS
20090004683 NASA Glenn Research Center, Cleveland, OH, United States
Effect of Upper-Cycle Temperature on the Load-Biased, Strain-Temperature Response of NiTi
Padula, Santo, II; Vaidyanathan, Raj; Gaydosh, Darrell; Noebe, Ronald; Bigelow, Glen; Garg, Anita; September 21, 2008; In English; The International Conference on Shape Memory and Superelastic Technologies (SMST) 2008, 21-25 sEP. 2008, Stresa, Italy; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.02
Report No.(s): E-16859; Copyright; Avail.: CASI: A03, Hardcopy
Over the past decade, interest in shape memory alloy based actuators has increased as the primary benefits of these solid-state devices have become more apparent. However, much is still unknown about the characteristic behavior of these materials when used in actuator applications. Recently we have shown that the maximum temperature reached during thermal cycling under isobaric conditions could significantly affect the observed mechanical response of NiTi (55 wt% Ni), especially the amount of transformation strain available for actuation and thus work output. This investigation extends that original work to ascertain whether further increases in the upper-cycle temperature would produce additional improvement in the work output of the material, which has a stress-free Af of 113 oC, and to determine the optimum cyclic conditions. Thus, isobaric, thermal-cycle experiments were conducted in the aforementioned alloy at various stress levels from 50-300 MPa using upper-cycle temperatures of 165, 200, 230, 260, 290, 320 and 350 oC. The data indicated that the amount of applied stress influenced the transformation strain available in the system, as would be expected. However, the maximum temperature reached during the thermal excursion also plays a role in determining the transformation strain, with the maximum transformation strain being developed by thermal cycling to 290 oC. In situ, neutron diffraction showed that the differences in transformation strain were related to differences in martensite texture within the microstructure when cycling to different upper-cycle temperatures. Hence, understanding this effect is important to optimizing the operation of SMA-based actuators and could lead to new methods for processing and training shape memory alloys for optimal performance.
Author
THERMAL CYCLING TESTS; STRESS-STRAIN RELATIONSHIPS; NICKEL ALLOYS; TITANIUM ALLOYS; LOADS (FORCES); SHAPE MEMORY ALLOYS; NEUTRON DIFFRACTION
20090004684 NASA Glenn Research Center, Cleveland, OH, United States
NASA's Evolutionary Xenon Thruster: The NEXT Ion Propulsion System for Solar System Exploration
Pencil, Eric J.; Benson, Scott W.; June 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 346620.01.03.01
Report No.(s): E-16860; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004684
This viewgraph presentation reviews NASA s Evolutionary Xenon Thruster (NEXT) Ion Propulsion system. The NEXT project is developing a solar electric ion propulsion system. The NEXT project is advancing the capability of ion propulsion to meet NASA robotic science mission needs. The NEXT system is planned to significantly improve performance over the state of the art electric propulsion systems, such as NASA Solar Electric Propulsion Technology Application Readiness (NSTAR). The status of NEXT development is reviewed, including information on the NEXT Thruster, the power processing unit, the propellant management system (PMS), the digital control interface unit, and the gimbal. Block diagrams NEXT system are presented. Also a review of the lessons learned from the Dawn and NSTAR systems is provided. In summary the NEXT project activities through 2007 have brought next-generation ion propulsion technology to a sufficient maturity level.
CASI
ELECTRIC PROPULSION; ION ENGINES; ION PROPULSION; PROPULSION SYSTEM PERFORMANCE; SOLAR ELECTRIC PROPULSION
20090004685 NASA Glenn Research Center, Cleveland, OH, United States
NASA's Evolutionary Xenon Thruster (NEXT) Ion Propulsion System Information Summary
Pencil, Eirc S.; Benson, Scott W.; August 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 346620.01.03.01
Report No.(s): E-16861; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004685
This document is a guide to New Frontiers mission proposal teams. The document describes the development and status of the NASA's Evolutionary Xenon Thruster (NEXT) ion propulsion system (IPS) technology, its application to planetary missions, and the process anticipated to transition NEXT to the first flight mission.
Derived from text
ION PROPULSION; XENON; THRUSTORS; FABRICATION; SYSTEMS ENGINEERING
20090004686 NASA Glenn Research Center, Cleveland, OH, United States
An Overview of Recent Phased Array Measurements at NASA Glenn
Podboy, Gary G.; September 23, 2008; In English; TWG Meeting, 23-24 Sep. 2008, Williamsburg, VA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.18.02
Report No.(s): E-16862; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004686
A review of measurements made at the NASA Glenn Research Center using an OptiNAV Array 48 phased array system is provided. Data were acquired on a series of round convergent and convergent-divergent nozzles using the Small Hot Jet Acoustic Rig. Tests were conducted over a range of jet operating conditions, including subsonic and supersonic and cold and hot jets. Phased array measurements were also acquired on a Williams International FJ44 engine. These measurements show how the noise generated by the engine is split between the inlet-radiated and exhaust-radiated components. The data also show inlet noise being reflected off of the inflow control device used during the test.
Author
PHASED ARRAYS; CONVERGENT-DIVERGENT NOZZLES; CONVERGENT NOZZLES; JET FLOW
20090004687 NASA Glenn Research Center, Cleveland, OH, United States
SDR/STRS Flight Experiment and the Role of SDR-Based Communication and Navigation Systems
Reinhart, Richard C.; February 25, 2008; In English; IDGA 6th Annual Software Radio Summit, 25-28 Feb. 2008, Vienna, VA, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 439432.04.07.0
Report No.(s): E-16867; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004687
This presentation describes an open architecture SDR (software defined radio) infrastructure, suitable for space-based radios and operations, entitled Space Telecommunications Radio System (STRS). SDR technologies will endow space and planetary exploration systems with dramatically increased capability, reduced power consumption, and less mass than conventional systems, at costs reduced by vigorous competition, hardware commonality, dense integration, minimizing the impact of parts obsolescence, improved interoperability, and software re-use. To advance the SDR architecture technology and demonstrate its applicability in space, NASA is developing a space experiment of multiple SDRs each with various waveforms to communicate with NASA s TDRSS satellite and ground networks, and the GPS constellation. An experiments program will investigate S-band and Ka-band communications, navigation, and networking technologies and operations.
Author
RADIO COMMUNICATION; ARCHITECTURE (COMPUTERS); ULTRAHIGH FREQUENCIES; TDR SATELLITES; SUPERHIGH FREQUENCIES; SATELLITE NETWORKS; RADIO EQUIPMENT; GLOBAL POSITIONING SYSTEM
20090004693 NASA Glenn Research Center, Cleveland, OH, United States
Doping of BiScO3-PbTiO3 Ceramics for Enhanced Properties
Sehirlioglu, Alp; Sayir, Ali; Dynys, Fred; October 05, 2008; In English; Materials Science and Technology Meeting ASM/ACERS, 5-9 Oct. 2008, Pittsburgh, PA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): AFOSR FA-9550-06.1-0260WBS 984754.02.07.03.16.04
Report No.(s): E-16871; Copyright; Avail.: CASI: A03, Hardcopy
High-temperature piezoelectrics are a key technology for aeronautics and aerospace applications such as fuel modulation to increase the engine efficiency and decrease emissions. The principal challenge for the insertion of piezoelectric materials is the limitation on upper use temperature which is due to low Curie-Temperature (T(sub c) and increasing electrical conductivity. BiScO3 -PbTiO3 (BS-PT) system is a promising candidate for improving the operating temperature for piezoelectric actuators due to its high TC (>400 C). Effects of Zr and Mn doping of the BS-PT ceramics have been studied and all electrical and electromechanical properties for Sc-deficient and Ti-deficient BS- PT ceramics are reported as a function of electrical field and temperature. Donor doping with Zr and Mn (in Sc deficient compositions) increased the DC-resistivity and decreased tan at all temperatures. Resulting ceramics exhibited saturated hysteresis loops with low losses and showed no dependence on the applied field (above twice the coercive field) and measurement frequency.
Author
PIEZOELECTRICITY; HIGH TEMPERATURE; CERAMICS; EXHAUST EMISSION; ELECTRICAL PROPERTIES; COMBUSTION PRODUCTS; ACTUATORS
20090004695 NASA Glenn Research Center, Cleveland, OH, United States
Liquid Methane/Liquid Oxygen Propellant Conditioning Feed System (PCFS) Test Rigs
Skaff, A.; Grasl, S.; Nguyen, C.; Hockenberry S.; Schubert, J.; Arrington, L.; Vasek, T.; December 08, 2008; In English; JANNAF 3rd Spacecraft Propulsion Joint Subcommittee Meeting, 8-12 Dec. 2008, Orland, FL, United States; Original contains color illustrations
Contract(s)/Grant(s): NNCO5CA95C
Report No.(s): E-16872; Copyright; Avail.: CASI: A03, Hardcopy
As part of their Propulsion and Cryogenic Advanced Development (PCAD) program, NASA has embarked upon an effort to develop chemical rocket engines which utilize non-toxic, cryogenic propellants such as liquid oxygen (LO2) and liquid methane (LCH4). This effort includes the development and testing of a 100 lbf Reaction Control Engine (RCE) that will be used to evaluate the performance of a LO2/LCH4 rocket engine over a broad range of propellant temperatures and pressures. This testing will take place at NASA-Glenn Research Center's (GRC) Research Combustion Laboratory (RCL) test facility in Cleveland, OH, and is currently scheduled to begin in late 2008. While the initial tests will be performed at sea level, follow-on testing will be performed at NASA-GRC's Altitude Combustion Stand (ACS) for altitude testing. In support of these tests, Sierra Lobo, Inc. (SLI) has designed, developed, and fabricated two separate portable propellant feed systems under the Propellant Conditioning and Feed System (PCFS) task: one system for LCH4, and one for LO2. These systems will be capable of supplying propellants over a large range of conditions from highly densified to several hundred pounds per square inch (psi) saturated. This paper presents the details of the PCFS design and explores the full capability of these propellant feed systems.
Author
METHANE; LIQUID OXYGEN; PROPELLANTS; CHEMICAL PROPULSION; CRYOGENIC ROCKET PROPELLANTS; FEED SYSTEMS; ROCKET ENGINES; LIQUEFIED GASES; COMBUSTION
20090004702 NASA Langley Research Center, Hampton, VA, United States
Fluorescence Imaging and Streamline Visualization of Hypersonic Flow over Rapid Prototype Wind-Tunnel Models
Danehy, Paul M.; Alderfer, David W.; Inman, Jennifer A.; Berger, Karen T.; Buck, Gregory M.; Schwartz, Richard J.; [2008]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.07.06.02
Report No.(s): LF99-5899; Copyright; Avail.: CASI: A03, Hardcopy
Reentry models for use in hypersonic wind tunnel tests were fabricated using a stereolithography apparatus. These models were produced in one day or less, which is a significant time savings compared to the manufacture of ceramic or metal models. The models were tested in the NASA Langley Research Center 31-Inch Mach 10 Air Tunnel. Only a few of the models survived repeated tests in the tunnel, and several failure modes of the models were identified. Planar laser-induced fluorescence (PLIF) of nitric oxide (NO) was used to visualize the flowfields in the wakes of these models. Pure NO was either seeded through tubes plumbed into the model or via a tube attached to the strut holding the model, which provided localized addition of NO into the model s wake through a porous metal cylinder attached to the end of the tube. Models included several 2- inch diameter Inflatable Reentry Vehicle Experiment (IRVE) models and 5-inch diameter Crew Exploration Vehicle (CEV) models. Various model configurations and NO seeding methods were used, including a new streamwise visualization method based on PLIF. Virtual Diagnostics Interface (ViDI) technology, developed at NASA Langley Research Center, was used to visualize the data sets in post processing. The use of calibration "dotcards" was investigated to correct for camera perspective and lens distortions in the PLIF images.
Author
WIND TUNNEL MODELS; LITHOGRAPHY; REENTRY VEHICLES; WIND TUNNEL TESTS; MATHEMATICAL MODELS; LAMINAR FLOW; LASER INDUCED FLUORESCENCE; HYPERSONIC WIND TUNNELS; IMAGING TECHNIQUES; FLOW VISUALIZATION
20090004704 NASA Langley Research Center, Hampton, VA, United States
Analytic Formulation and Numerical Implementation of an Acoustic Pressure Gradient Prediction
Lee, Seongkyu; Brentner, Kenneth S.; Farassat, F.; Morris, Philip J.; April 24, 2008; In English
Contract(s)/Grant(s): NNL05AD50PWBS 561581.02.07.07
Copyright; Avail.: CASI: A03, Hardcopy
Two new analytical formulations of the acoustic pressure gradient have been developed and implemented in the PSU-WOPWOP rotor noise prediction code. The pressure gradient can be used to solve the boundary condition for scattering problems and it is a key aspect to solve acoustic scattering problems. The first formulation is derived from the gradient of the Ffowcs Williams-Hawkings (FW-H) equation. This formulation has a form involving the observer time differentiation outside the integrals. In the second formulation, the time differentiation is taken inside the integrals analytically. This formulation avoids the numerical time differentiation with respect to the observer time, which is computationally more efficient. The acoustic pressure gradient predicted by these new formulations is validated through comparison with available exact solutions for a stationary and moving monopole sources. The agreement between the predictions and exact solutions is excellent. The formulations are applied to the rotor noise problems for two model rotors. A purely numerical approach is compared with the analytical formulations. The agreement between the analytical formulations and the numerical method is excellent for both stationary and moving observer cases.
Author
ANALYSIS (MATHEMATICS); NUMERICAL DIFFERENTIATION; ACOUSTIC SCATTERING; PRESSURE GRADIENTS; NOISE PREDICTION; FFOWCS WILLIAMS-HAWKINGS EQUATION; BOUNDARY CONDITIONS; SOUND PRESSURE; ROTOR AERODYNAMICS
Additions to the NASA Aeronautics and Space Database as of 02/06/2009
20090004864 NASA Glenn Research Center, Cleveland, OH, United States
SBIR/STTR Programs
Stegeman, James D.; Comstock, Douglas; November 12, 2008; In English; National SBIR Conference, 14 Nov. 2008, Hartford, CT, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 128636.01.03.01
Report No.(s): E-16873; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004864
This presentation provides an overview of the NASA mission and overviews of both the Innovative Partnerships Program (IPP) and Small Business Innovation Research (SBIR) programs and how they relate to each other and to the NASA mission. Examples are provided concerning NASA technology needs and how the SBIR program has not only enabled technology development to meet those needs, but has also facilitated the infusion of that technology into the NASA mission.
Author
NASA PROGRAMS; RESEARCH AND DEVELOPMENT; TECHNOLOGY ASSESSMENT
20090004866 NASA Glenn Research Center, Cleveland, OH, United States
Lunar Dust Characterization Activity at GRC
Street, Kenneth W.; November 18, 2008; In English; NASA Lunar Dust Filtration and Separations Workshop, 18 Nov. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 936374.03.01.03
Report No.(s): E-16874; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004866
The fidelity of lunar simulants as compared to actual regolith is evaluated using Figures of Merit (FOM) which are based on four criteria: Particle Size, Particle Shape, Composition, and Density of the bulk material. In practice, equipment testing will require other information about both the physical properties (mainly of the dust fraction) and composition as a function of particle size. At Glenn Research Center (GRC) we are involved in evaluating a number of simulant properties of consequence to testing of lunar equipment in a relevant environment, in order to meet Technology Readiness Level (TRL) 6 criteria. Bulk regolith has been characterized for many decades, but surprisingly little work has been done on the dust fraction (particles less than 20 micrometers in diameter). GRC is currently addressing the information shortfall by characterizing the following physical properties: Particle Size Distribution, Adhesion, Abrasivity, Surface Energy, Magnetic Susceptibility, Tribocharging and Surface Chemistry/Reactivity. Since some of these properties are also dependent on the size of the particles we have undertaken the construction of a six stage axial cyclone particle separator to fractionate dust into discrete particle size distributions for subsequent evaluation of these properties. An introduction to this work and progress to date will be presented.
Author
CHARACTERIZATION; LUNAR DUST; REGOLITH; LUNAR GEOLOGY; LUNAR ENVIRONMENT
20090004878 NASA Glenn Research Center, Cleveland, OH, United States
Some Expected Characteristics of Lunar Dust: A Geological View Applied to Engineering
Street, Kenneth W.; Schrader, Christian M.; Rickman, Doug; October 05, 2008; In English; Geological Society of America Meeting, 9 Oct. 2008, Houston, TX, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 092837.04.02.01.03
Report No.(s): E-16875; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004878
Compared to the Earth the geologic nature of the lunar regolith is quite distinct. Even though similar minerals exist on the Earth and Moon, they may have very different properties due to the absence of chemical modification in the lunar environment. The engineering properties of the lunar regolith reflect aspects of the parent rock and the consequences of hypervelocity meteor bombardment. On scales relevant to machinery and chemical processing for In-Situ Resource Utilization, ISRU (such as water production), the lunar regolith compositional range is much more restricted than terrestrial material. This fact impacts predictions of properties required by design engineers for constructing equipment for lunar use. In this paper two examples will be covered. 1) Abrasion is related to hardness and hardness is a commonly measured property for both minerals and engineering materials. Although different hardness scales are routinely employed for minerals and engineering materials, a significant amount of literature is available relating the two. As one example, we will discuss how to relate hardness to abrasion for the design of lunar equipment. We also indicate how abundant the various mineral phases are and typical size distributions for lunar regolith which will impact abrasive nature. 2) Mineral characteristics that may seem trivial to the non-geologist or material scientist may have significant bearing on ISRU processing technologies. As a second example we discuss the impact of traces of F-, Cl-, and OH-, H2O, CO2, and sulfur species which can radically alter melting points and the corrosive nature of reaction products thereby significantly changing bulk chemistry and associated processing technologies. For many engineering uses, a simulant s fidelity to bulk lunar regolith chemistry may be insufficient. Therefore, simulant users need to engage in continuing dialogue with simulant developers and geoscientists.
Author
LUNAR ENVIRONMENT; LUNAR DUST; LUNAR ROCKS; MINERALOGY; SIZE DISTRIBUTION; GEOLOGY; ABRASIVES
20090004883 NASA Langley Research Center, Hampton, VA, United States
Benchmark Analysis of Pion Contribution from Galactic Cosmic Rays
Aghara, Sukesh K.; Blattnig, Steve R.; Norbury, John W.; Singleterry, Robert C., Jr.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 651549.02.07.01
Report No.(s): NASA/TP-2008-215556; L-19400; Copyright; Avail.: CASI: A03, Hardcopy
Shielding strategies for extended stays in space must include a comprehensive resolution of the secondary radiation environment inside the spacecraft induced by the primary, external radiation. The distribution of absorbed dose and dose equivalent is a function of the type, energy and population of these secondary products. A systematic verification and validation effort is underway for HZETRN, which is a space radiation transport code currently used by NASA. It performs neutron, proton and heavy ion transport explicitly, but it does not take into account the production and transport of mesons, photons and leptons. The question naturally arises as to what is the contribution of these particles to space radiation. The pion has a production kinetic energy threshold of about 280 MeV. The Galactic cosmic ray (GCR) spectra, coincidentally, reaches flux maxima in the hundreds of MeV range, corresponding to the pion production threshold. We present results from the Monte Carlo code MCNPX, showing the effect of lepton and meson physics when produced and transported explicitly in a GCR environment.
Author
GALACTIC COSMIC RAYS; PIONS; EXTRATERRESTRIAL RADIATION; RADIATION DOSAGE; RADIATION SHIELDING; RADIATION TRANSPORT; MONTE CARLO METHOD
20090004893 NASA Glenn Research Center, Cleveland, OH, United States
Model Attitude and Deformation Measurements at the NASA Glenn Research Center
Woike, Mark R.; January 07, 2008; In English; 46th AIAA Model Attitude and Deformation Working Group Meeting, 7-10 Jan. 2008, Reno, NV, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 122711.03.06.03.01
Report No.(s): E-16877; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004893
The NASA Glenn Research Center is currently participating in an American Institute of Aeronautics and Astronautics (AIAA) sponsored Model Attitude and Deformation Working Group. This working group is chartered to develop a best practices document dealing with the measurement of two primary areas of wind tunnel measurements, 1) model attitude including alpha, beta and roll angle, and 2) model deformation. Model attitude is a principle variable in making aerodynamic and force measurements in a wind tunnel. Model deformation affects measured forces, moments and other measured aerodynamic parameters. The working group comprises of membership from industry, academia, and the Department of Defense (DoD). Each member of the working group gave a presentation on the methods and techniques that they are using to make model attitude and deformation measurements. This presentation covers the NASA Glenn Research Center s approach in making model attitude and deformation measurements.
Author
ATTITUDE (INCLINATION); DEFORMATION; WIND TUNNEL TESTS; SUPERSONIC WIND TUNNELS; WIND TUNNEL MODELS; AERONAUTICS
20090004895 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States
Commercial Sensor Survey Fiscal Year 2008 Compendium Radiation Test Report
Becker, Heidi N.; Dolphin, Michael D.; Thorbourn, Dennis O.; Alexander, James W.; Salomon, Phil M.; October 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS7-03001WBS 939904.01.11.30; JPL Proj. 102197
Report No.(s): JPL Publication 08-26; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://dx.doi.org/2014/41025
The NASA Electronic Parts and Packaging (NEPP) Program Sensor Technology Commercial Sensor Survey task is geared toward benefiting future NASA space missions with low-cost, short-duty-cycle, visible-wavelength imaging needs. Such applications could include imaging for educational outreach purposes or short surveys of spacecraft, planetary, or lunar surfaces. Under the task, inexpensive commercial grade CMOS sensors were surveyed in fiscal year 2007 (FY07) and three sensors were selected for total ionizing dose (TID) and displacement damage dose (DDD) tolerance testing. The selected sensors had to meet selection criteria chosen to support small, low-mass cameras that produce good resolution color images. These criteria were discussed in detail in [1], and are provided again in Appendix 1 of this document. This compendium provides results for all radiation testing performed in FY08 on the Micron and OmniVision sensors that were selected in FY07 for radiation tolerance testing
Author
RADIATION TOLERANCE; RADIATION EFFECTS; MEASURING INSTRUMENTS
20090004912 ENSCO, Inc., Cocoa Beach, FL, United States
Completion of the Edward Air Force Base Statistical Guidance Wind Tool
Dreher, Joseph G.; October 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): NNK06MA70C
Report No.(s): NASA/CR-2008-214751; Copyright; Avail.: CASI: A03, Hardcopy
The goal of this task was to develop a GUI using EAFB wind tower data similar to the KSC SLF peak wind tool that is already in operations at SMG. In 2004, MSFC personnel began work to replicate the KSC SLF tool using several wind towers at EAFB. They completed the analysis and QC of the data, but due to higher priority work did not start development of the GUI. MSFC personnel calculated wind climatologies and probabilities of 10-minute peak wind occurrence based on the 2-minute average wind speed for several EAFB wind towers. Once the data were QC'ed and analyzed the climatologies were calculated following the methodology outlined in Lambert (2003). The climatologies were calculated for each tower and month, and then were stratified by hour, direction (10" sectors), and direction (45" sectors)/hour. For all climatologies, MSFC calculated the mean, standard deviation and observation counts of the Zminute average and 10-minute peak wind speeds. MSFC personnel also calculated empirical and modeled probabilities of meeting or exceeding specific 10- minute peak wind speeds using PDFs. The empirical PDFs were asymmetrical and bounded on the left by the 2- minute average wind speed. They calculated the parametric PDFs by fitting the GEV distribution to the empirical distributions. Parametric PDFs were calculated in order to smooth and interpolate over variations in the observed values due to possible under-sampling of certain peak winds and to estimate probabilities associated with average winds outside the observed range. MSFC calculated the individual probabilities of meeting or exceeding specific 10- minute peak wind speeds by integrating the area under each curve. The probabilities assist SMG forecasters in assessing the shuttle FR for various Zminute average wind speeds. The A M ' obtained the processed EAFB data from Dr. Lee Bums of MSFC and reformatted them for input to Excel PivotTables, which allow users to display different values with point-click-drag techniques. The GUI was created from the PivotTables using VBA code. It is run through a macro within Excel and allows forecasters to quickly display and interpret peak wind climatology and probabilities in a fast-paced operational environment. The GUI was designed to look and operate exactly the same as the KSC SLF tool since SMG forecasters were already familiar with that product. SMG feedback was continually incorporated into the GUI ensuring the end product met their needs. The final version of the GUI along with all climatologies, PDFs, and probabilities has been delivered to SMG and will be put into operational use.
Author
GRAPHICAL USER INTERFACE; WIND MEASUREMENT; CLIMATOLOGY; WIND VELOCITY; WIND (METEOROLOGY); FORECASTING; PROBABILITY THEORY
20090004981 Colorado Univ., Boulder, CO United States
Mounting system for optical frequency reference cavities
Notcutt, Mark, Inventor; Hall, John L., Inventor; Ma, Long-Sheng, Inventor; December 30, 2008; In English
Contract(s)/Grant(s): NAG5-10368
Patent Info.: August 25, 2006US-Patent-7,469,454; US-Patent-Appl-SN-11/510,269
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004981
A technique for reducing the vibration sensitivity of laser-stabilizing optical reference cavities is based upon an improved design and mounting method for the cavity, wherein the cavity is mounted vertically. It is suspended at one plane, around the spacer cylinder, equidistant from the mirror ends of the cavity. The suspension element is a collar of an extremely low thermal expansion coefficient material, which surrounds the spacer cylinder and contacts it uniformly. Once the collar has been properly located, it is cemented in place so that the spacer cylinder is uniformly supported and does not have to be squeezed at all. The collar also includes a number of cavities partially bored into its lower flat surface, around the axial bore. These cavities are support points, into which mounting base pins will be inserted. Hence the collar is supported at a minimum of three points.
Official Gazette of the U.S. Patent and Trademark Office
MOUNTING; OPTICAL RESONATORS; SENSITIVITY; VIBRATION DAMPING; LASER APPLICATIONS; LASER CAVITIES
20090004982 NASA, Washington, DC United States
Magnetostrictive valve assembly
Richard, James A., Inventor; December 30, 2008; In English
Patent Info.: September 1, 2006US-Patent-7,469,878; US-Patent-Appl-SN-11/518,733
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004982
A magnetostrictive valve assembly includes a housing that defines a passage with a seat being formed therein. A magnetically-biased and axially-compressed magnetostrictive assembly slidingly fitted in the passage is configured as a hollow and open-ended conduit adapted to support a flow of a fluid therethrough. Current-carrying coil(s) disposed about the passage in the region of the magnetostrictive assembly generate a magnetic field in the passage when current flows through the coil(s). A hollow valve body with side ports is coupled on one end thereof to an axial end of the magnetostrictive assembly. The other end of the valve body is designed to seal with the seat formed in the housing's passage when brought into contact therewith.
Official Gazette of the U.S. Patent and Trademark Office
MAGNETOSTRICTION; VALVES; ROCKET ENGINES
20090004983 California Inst. of Tech., Pasadena, CA United States
Direct methanol feed fuel cell and system
Surampudi, Subbarao, Inventor; Frank, Harvey A., Inventor; Narayanan, Sekharipuram R., Inventor; Chun, William, Inventor; Jeffries-Nakamura, Barbara, Inventor; Kindler, Andrew, Inventor; Halpert, Gerald, Inventor; December 30, 2008; In English
Contract(s)/Grant(s): NAS7-1407
Patent Info.: March 9, 2004US-Patent-7,470,478; US-Patent-Appl-SN-10/797,625
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004983
Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous.
Official Gazette of the U.S. Patent and Trademark Office
ELECTRODES; FEED SYSTEMS; FUEL CELLS; METHYL ALCOHOL
20090004984 Columbia Univ., New York, NY United States
Cross reactive arrays of three-way junction sensors for steroid determination
Stojanovic, Milan N., Inventor; Landry, Donald, Inventor; Nikic, Dragan B., Inventor; December 30, 2008; In English
Contract(s)/Grant(s): NAS2-02039
Patent Info.: October 14, 2005US-Patent-7,470,516; US-Patent-Appl-SN-11/251,496
No Copyright; Avail.: CASI: A08, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004984
This invention provides analyte sensitive oligonucleotide compositions for detecting and analyzing analytes in solution, including complex solutions using cross reactive arrays of analyte sensitive oligonucleotide compositions.
Official Gazette of the U.S. Patent and Trademark Office
DETECTION; OLIGONUCLEOTIDES; REACTIVITY; STEROIDS
Additions to the NASA Aeronautics and Space Database as of 02/09/2009
20090004998 NASA Johnson Space Center, Houston, TX, United States
Human Adaptation to Space: Space Physiology and Countermeasures
Fogarty, Jennifer; [2009]; In English; NASA Human Health and Performance Technology, 15 Jan. 2009, Houston, TX, United States; Original contains color illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090004998
This viewgraph presentation reviews human physiological responses to spaceflight, and the countermeasures taken to prevent adverse effects of manned space flight. The topics include: 1) Human Spaceflight Experience; 2) Human Response to Spaceflight; 3) ISS Expeditions 1-16; 4) Countermeasure; and 5) Biomedical Data;
CASI
AEROSPACE MEDICINE; HUMAN TOLERANCES; MANNED SPACE FLIGHT; PHYSIOLOGICAL RESPONSES; SPACE ADAPTATION SYNDROME; INTERNATIONAL SPACE STATION
20090005021 NASA Glenn Research Center, Cleveland, OH, United States
Estimating the Need for Medical Intervention due to Sleep Disruption on the International Space Station
Myers, Jerry G.; Lewandowski, Beth E.; Brooker, John E.; Hurst, S. R.; Mallis, Melissa M.; Caldwell, J. Lynn; September 29, 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 444543.01.02.01
Report No.(s): E-16856; Paper ID:1499; Copyright; Avail.: CASI: A03, Hardcopy
During ISS and shuttle missions, difficulties with sleep affect more than half of all US crews. Mitigation strategies to help astronauts cope with the challenges of disrupted sleep patterns can negatively impact both mission planning and vehicle design. The methods for addressing known detrimental impacts for some mission scenarios may have a substantial impact on vehicle specific consumable mass or volume or on the mission timeline. As part of the Integrated Medical Model (IMM) task, NASA Glenn Research Center is leading the development of a Monte Carlo based forecasting tool designed to determine the consumables required to address risks related to sleep disruption. The model currently focuses on the International Space Station and uses an algorithm that assembles representative mission schedules and feeds this into a well validated model that predicts relative levels of performance, and need for sleep (SAFTE Model, IBR Inc). Correlation of the resulting output to self-diagnosed needs for hypnotics, stimulants, and other pharmaceutical countermeasures, allows prediction of pharmaceutical use and the uncertainty of the specified prediction. This paper outlines a conceptual model for determining a rate of pharmaceutical utilization that can be used in the IMM model for comparison and optimization of mitigation methods with respect to all other significant medical needs and interventions.
Author
INTERNATIONAL SPACE STATION; SLEEP; SPACE SHUTTLE MISSIONS; AEROSPACE MEDICINE; HUMAN FACTORS ENGINEERING
20090005024 NASA Glenn Research Center, Cleveland, OH, United States
Preliminary Test Results of a Non-Contacting Finger Seal on a Herringbone-Grooved Rotor
Proctor, Margaret P.; Delgado, Irebert R.; November 18, 2008; In English; NASA Seals and Secondary Flows Symposium, 18 Nov. 2008, Cleveland, OH, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.15.02
Report No.(s): E-16864; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005024
Low leakage, non-contacting finger seals have potential to reduce gas turbine engine specific fuel consumption by 2 to 3 percent and to reduce direct operating costs by increasing the time between engine overhauls. A non-contacting finger seal with concentric lift-pads operating adjacent to a test rotor with herringbone grooves was statically tested at 300, 533, and 700 K inlet air temperatures at pressure differentials up to 576 kPa. Leakage flow factors were approximately 70 percent less than state-of-the-art labyrinth seals. Leakage rates are compared to first order predictions. Initial spin tests at 5000 rpm, 300 K inlet air temperature and pressure differentials to 241 kPa produced no measurable wear.
Author
LABYRINTH SEALS; ROTORS; SECONDARY FLOW; MATHEMATICAL MODELS; SPIN TESTS; GAS TURBINE ENGINES
20090005033 NASA Goddard Space Flight Center, Greenbelt, MD, United States; NASA Goddard Space Flight Center, Greenbelt, MD, United States
Catching Up on State Transitions in Cygnus X-1
Boeck, Moritz; Hanke, Manfred; Wilms, Joern; Pirner, Stefan; Grinberg, Victoria; Markoff, Sera; Pottschmidt, Katja; Nowak, Michael A.; Pooley, Guy; September 2008; In English; 7th Microquasar Workshop: Microquasars and Beyond, 1-5 Sep. 2008, Izmir, Turkey; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG06EO90A; DLR 50OR0801
Copyright; Avail.: CASI: A01, Hardcopy
In 2005 February we observed Cygnus X-1 over a period of 10 days quasi-continuously with the Rossi X-ray Timing Explorer and the Ryle telescope. We present the results of the spectral and timing analysis on a timescale of 90 min and show that the behavior of Cyg X-1 is similar to that found during our years long monitoring campaign. As a highlight we present evidence for a full transition from the hard to the soft state that happened during less than three hours. The observation provided a more complete picture of a state transition than before, especially concerning the evolution of the time lags, due to unique transition coverage and analysis with high time resolution.
Author
CYGNUS CONSTELLATION; X RAY SOURCES; SPECTRUM ANALYSIS
20090005034 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Highly Structured Wind in Vela X-1
Kreykenbohm, Ingo; Wilms, Joern; Kretschmar, Peter; Torrejon, Jose Miguel; Pottschmidt, Katja; Hanke, Manfred; Santangelo, Andrea; Ferrigno, Carlo; Staubert, Ruediger; September 08, 2008; In English; 7th INTEGRAL Workshop, 8-11 Sep. 2008, Copenhagen, Denmark; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG06EO90A
Copyright; Avail.: CASI: A03, Hardcopy
We present an in-depth analysis of the spectral and temporal behavior of a long almost uninterrupted INTEGRAL observation of Vela X-1 in Nov/Dec 2003. In addition to an already high activity level, Vela X-1 exhibited several very intense flares with a maximum intensity of more than 5 Crab in the 20 40 keV band. Furthermore Vela X-1 exhibited several off states where the source became undetectable with ISGRI. We interpret flares and off states as being due to the strongly structured wind of the optical companion: when Vela X-1 encounters a cavity in the wind with strongly reduced density, the flux will drop, thus potentially triggering the onset of the propeller effect which inhibits further accretion, thus giving rise to the off states. The required drop in density to trigger the propeller effect in Vela X-1 is of the same order as predicted by theoretical papers for the densities in the OB star winds. The same structured wind can give rise to the giant flares when Vela X-1 encounters a dense blob in the wind. Further temporal analysis revealed that a short lived QPO with a period of 6800 sec is present. The part of the light curve during which the QPO is present is very close to the off states and just following a high intensity state, thus showing that all these phenomena are related.
Author
X RAY BINARIES; STELLAR WINDS
20090005035 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Multi-Satellite Observations of Cygnus X-1 to Study the Focused Wind and Absorption Dips
Hanke, Manfred; Wilms, Joern; Boeck, Moritz; Nowak, Michael A.; Schultz, Norbert S.; Pottschmidt, Katja; Lee, Julia C.; September 2008; In English; 7th Microquasar Worksho, 1-5 Sep. 2008, Izmir, Turkey; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG06EO90A; 50OR0701
Copyright; Avail.: CASI: A02, Hardcopy
High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass accretion. Chandra-HETGS observations close to orbital phase 0 allow for an analysis of the photoionzed stellar wind at high resolution, but because of the strong variability due to soft X-ray absorption dips, simultaneous multi-satellite observations are required to track and understand the continuum, too. Besides an earlier joint Chandra and RXTE observation, we present first results from a recent campaign which represents the best broad-band spectrum of Cyg X-1 ever achieved: On 2008 April 18/19 we observed this source with XMM-Newton, Chandra, Suzaku, RXTE, INTEGRAL, Swift, and AGILE in X- and gamma-rays, as well as with VLA in the radio. After superior conjunction of the black hole, we detect soft X-ray absorption dips likely due to clumps in the focused wind covering greater than or equal to 95% of the X-ray source, with column densities likely to be of several 10(exp 23) cm(exp -2), which also affect photon energies above 20 keV via Compton scattering.
Author
CYGNUS CONSTELLATION; SATELLITE OBSERVATION; STELLAR WINDS; X RAY ABSORPTION
20090005036 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Modelling a Simultaneous Radio/X-Ray Flare from Cyg X-1
Leventis, Konstantinos; Markoff, Sera; Wilsm, Joern; Nowak, Michael A.; Maitra, Dipankar; Pottschmidt, Katja; Pooley, Guy G.; Kreykenbohm, Ingo; Rotschild, Richard E.; September 2008; In English; 7th Microquasar Workshop: Microquasars and Beyond, 1-5 Sep. 2008, Izmir, Turkey; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG06EO90A
Copyright; Avail.: CASI: A01, Hardcopy
The long-term monitoring campaign of Cyg X-1 has provided the detection of the first simultaneous radio/X-ray flare seen from that source. We investigate the physical characteristics of the event in terms of emission from a homogeneous, expanding blob of pair-plasma, superimposed on a baseline flux in both bands. We find that while the radio flare can be reconstructed under various configurations of a cooling blob, continuous (re)acceleration of particles inside the jet is necessary to sustain X-ray emission at the levels implied by the data, for the observed duration. We present major results of the modelling and discuss implications for the role of microquasar jets.
Author
CYGNUS CONSTELLATION; RADIO EMISSION; FLARES; ASTRONOMICAL MODELS
20090005037 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Automatic Extraction of Planetary Image Features
Troglio, G.; LeMoigne, J.; Moser, G.; Serpico, S. B.; Benediktsson, J. A.; [2009]; In English; Third International Conference on Space Mission Challenges for Information Technology (SMC-IT 2009), 19-23 Jul. 2009, Pasadena, CA, United States; Original contains color illustrations
Copyright; Avail.: CASI: A01, Hardcopy
With the launch of several Lunar missions such as the Lunar Reconnaissance Orbiter (LRO) and Chandrayaan-1, a large amount of Lunar images will be acquired and will need to be analyzed. Although many automatic feature extraction methods have been proposed and utilized for Earth remote sensing images, these methods are not always applicable to Lunar data that often present low contrast and uneven illumination characteristics. In this paper, we propose a new method for the extraction of Lunar features (that can be generalized to other planetary images), based on the combination of several image processing techniques, a watershed segmentation and the generalized Hough Transform. This feature extraction has many applications, among which image registration.
Author
IMAGE PROCESSING; DATA ACQUISITION; PATTERN RECOGNITION; PATTERN REGISTRATION; ALGORITHMS; LUNAR EXPLORATION
20090005038 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Global Land Data Assimilation System (GLDAS) Products, Services and Application from NASA Hydrology Data and Information Services Center (HDISC)
Fang, Hongliang; Beaudoing, Hiroko K.; Rodell, matthew; Teng, William L.; Vollmer, Bruce E.; [2009]; In English; ASPRS 2009 Annual Conference, 8-31 Mar. 2009, Baltimore, MD, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
The Global Land Data Assimilation System (GLDAS) is generating a series of land surface state (e.g., soil moisture and surface temperature) and flux (e.g., evaporation and sensible heat flux) products simulated by four land surface models (CLM, Mosaic, Noah and VIC). These products are now accessible at the Hydrology Data and Information Services Center (HDISC), a component of the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). Current data holdings include a set of 1.0 degree resolution data products from the four models, covering 1979 to the present; and a 0.25 degree data product from the Noah model, covering 2000 to the present. The products are in Gridded Binary (GRIB) format and can be accessed through a number of interfaces. Users can search the products through keywords and perform on-the-fly spatial and parameter subsetting and format conversion of selected data. More advanced visualization, access and analysis capabilities will be available in the future. The long term GLDAS data are used to develop climatology of water cycle components and to explore the teleconnections of droughts and pluvial.
Author
LAND MANAGEMENT; EARTH SCIENCES; DATA ACQUISITION; DATA INTEGRATION; INFORMATION SYSTEMS; CLIMATOLOGY; HYDROLOGY
20090005039 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Mechanical Overview of the International X-Ray Observatory
Robinson, David W.; McClelland, Ryan S.; [2009]; In English; 2009 IEEE Aerospace Conference, 7-14 Mar. 2009, Big Sky, MT, United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
The International X-ray Observatory (IXO) is a new collaboration between NASA, ESA, and JAXA which is under study for launch in 2020. IXO will be a large 6600 kilogram Great Observatory-class mission which will build upon the legacies of the Chandra and XMM-Newton X-ray observatories. It combines elements from NASA's Constellation-X program and ESA's XEUS program. The observatory will have a 20-25 meter focal length, which necessitates the use of a deployable instrument module. Currently the project is actively trading configurations and layouts of the various instruments and spacecraft components. This paper will provide a snapshot of the latest observatory configuration under consideration and summarize the observatory from the mechanical engineering perspective.
Author
ASTRONOMICAL OBSERVATORIES; SPACECRAFT CONFIGURATIONS; MECHANICAL ENGINEERING
Additions to the NASA Aeronautics and Space Database as of 02/10/2009
20090005099 NASA Johnson Space Center, Houston, TX, United States
Solid State Light Evaluation in the U.S. Lab Mockup
Maida, James c.; Bowen, Charles K.; Wheelwright, Chuck; January 09, 2009; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
This document constitutes the publication of work performed by the Space Human Factors Laboratory (mail code SF5 at the time) at the Johnson Space Center (JSC) in the months of June and July of 2000. At that time, the Space Human Factors Laboratory was part of the Space Human Factors Branch in the Flight Projects Division of the Space and Life Directorate. This report was originally to be a document for internal consumption only at JSC as it was seen to be only preliminary work for the further development of solid state illumination for general lighting on future space vehicles and the International Space Station (ISS). Due to funding constraints, immediate follow-on efforts were delayed and the need for publication of this document was overcome by other events. However, in recent years and with the development and deployment of a solid state light luminaire prototype on ISS, the time was overdue for publishing this information for general distribution and reference. Solid state lights (SSLs) are being developed to potentially replace the general luminaire assemblies (GLAs) currently in service in the International Space Station (ISS) and included in designs of modules for the ISS. The SSLs consist of arrays of light emitting diodes (LEDs), small solid state electronic devices that produce visible light in proportion to the electrical current flowing through them. Recent progressive advances in electrical power-to-light conversion efficiency in LED technology have allowed the consideration of LEDs as replacements for incandescent and fluorescent light sources in many circumstances, and their inherent advantages in ruggedness, reliability, and life expectancy make them attractive for applications in spacecraft. One potential area of application for the SSLs in the U.S. Laboratory Module of the ISS. This study addresses the suitability of the SSLs as replacements for the GLAs in this application.
Derived from text
INTERNATIONAL SPACE STATION; LIGHT SOURCES; SOLID STATE DEVICES; HUMAN FACTORS ENGINEERING; LIGHT ADAPTATION
20090005100 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States
Radiation Tests of Highly Scaled High Density Commercial Nonvolatile Flash Memories
Irom, Farokh; Nguyen, Duc N.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS7-03001Proj. 102197
Report No.(s): JPL Publication 08-27; Copyright; Avail.: CASI: A03, Hardcopy
We tested the advanced commercial high density 8 Gb NAND flash memory from Samsung with heavy ions. We also tested the advanced commercial NOR flash memory from Spansion. The general conclusion is that the SEU and SEFI cross section is smaller than the older generation of flash memories. Another observation is a new high current phenomenon in the high density NAND and NOR flash memories. This high current phenomenon is destructive for Samsung NAND flash memory during READ and PROGRAM modes and during PROGRAM mode for Spansion NOR flash. The results in this report show that the high current phenomenon in scaled devices is a complex problem that is not fully understood. Processing details and oxide defects appear to play a role in gate rupture, and the differences in experimental observations by different groups may be because of difference in semiconductor processing. More work needs to be done to increase the level of understanding as well as how it may affect highly scaled commercial devices. The high current spikes phenomenon is on verge of becoming a serious problem as scaling continues and the transistors sizes become comparable to ion track widths.
Author
COMPUTER STORAGE DEVICES; ELECTRONIC EQUIPMENT; TEST FACILITIES; MEMORY (COMPUTERS); RADIATION
Additions to the NASA Aeronautics and Space Database as of 02/12/2009
20090005167 NASA Dryden Flight Research Center, Edwards, CA, United States
X-48B Flight Research Progress Overview
Risch, Tim; Cosentino, Gary; Regan, Chris; Kisska, Michael; Princen, Norman; January 05, 2009; In English; 47th AIAA Aerospace Sciences Meeting, 5-8 Jan. 2009, Orlando, FL., United States; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Program Objectives; I. Assess stability & control characteristics of a BWB class vehicle in free-flight conditions: a) Assess dynamic interaction of control surfaces; b) Assess control requirements to accommodate asymmetric thrust; c) Assess stability and controllability about each axis at a range of flight conditions II. Assess flight control algorithms designed to provide desired flight characteristics: a) Assess control surface allocation and blending; b) Assess edge of envelope protection schemes; c) Assess takeoff and landing characteristics; d) Test experimental control laws and control design methods. III. Evaluate prediction and test methods for BWB class vehicles: a) Correlate flight measurements with ground-based predictions and measurements.
Author
AERODYNAMIC CHARACTERISTICS; BLENDED-WING-BODY CONFIGURATIONS; CONTROL THEORY; IN-FLIGHT MONITORING; PREDICTION ANALYSIS TECHNIQUES; FLIGHT CONTROL
20090005170 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States
Distribution Automation Applications of Fiber Optics
Kirkham, Harold; Johnston, Alan; Friend, Heather; October 15, 2008; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NAS7-03001; DE-AI01-79ET 29372 (Mod. A009)
Report No.(s): Jpl Publication 89-10, Rev A; No Copyright; Avail.: CASI: A06, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005170
Motivations for interest and research in distribution automation are discussed. The communication requirements of distribution automation are examined, and shown to exceed the capabilities of power line carrier, radio and telephone systems. A fiber-optic-based communication system is described that is co-located with the distribution system and that could satisfy the data rate and reliability requirements. A cost comparison shows that it could be constructed at a cost that is similar to that of a power line carrier system. The requirements for fiber optic sensors for distribution automation are discussed. The design of a data link suitable for optically-powered electronic sensing is presented. Empirical results are given. A modeling technique that has been used to understand the reflections of guided light from a variety of surfaces is described. An optical position indicator design is discussed. Systems aspects of distribution automation are discussed, in particular the lack of interface, communications and data standards. The economics of distribution automation are examined.
Author
FIBER OPTICS; AUTOMATION; ECONOMICS; ELECTRIC POWER
20090005178 NASA Glenn Research Center, Cleveland, OH, United States
Testing of a Microwave Blade Tip Clearance Sensor at the NASA Glenn Research Center
Woike, Mark R.; Roeder, James W.; Hughes, Christopher E.; Bencic, Timothy J.; January 05, 2009; In English; 47th AIAA Aerosciences Conference, 5-8 Jan. 2009, Orlando, FL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.13.06
Report No.(s): E-16826; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005178
The development of new active tip clearance control and structural health monitoring schemes in turbine engines and other types of rotating machinery requires sensors that are highly accurate and can operate in a high temperature environment. The use of a microwave sensor to acquire blade tip clearance and tip timing measurements is being explored at the NASA Glenn Research Center. The microwave blade tip clearance sensor works on principles that are very similar to a short range radar system. The sensor sends a continuous microwave signal towards a target and measures the reflected signal. The phase difference of the reflected signal is directly proportional to the distance between the sensor and the target being measured. This type of sensor is beneficial in that it has the ability to operate at extremely high temperatures and is unaffected by contaminants that may be present in turbine engines. The use of microwave sensors for this application is a new concept. Techniques on calibrating the sensors along with installation effects are not well quantified as they are for other sensor technologies. Developing calibration techniques and evaluating installation effects are essential in using these sensors to make tip clearance and tip timing measurements. As a means of better understanding these issues, the microwave sensors were used on a bench top calibration rig, a large axial vane fan, and a turbofan. Background on the microwave tip clearance sensor, an overview of their calibration, and the results from their use on the axial vane fan and the turbofan will be presented in this paper.
Author
BLADE TIPS; MICROWAVE SENSORS; TURBINE ENGINES; CLEARANCES; TIME MEASUREMENT; CONTAMINANTS; HIGH TEMPERATURE ENVIRONMENTS; ACTIVE CONTROL; CALIBRATING
20090005179 Lockheed Martin Engineering and Science Services, Hampton, VA, United States
Characterization of Solid Polymers, Ceramic Gap Filler, and Closed-Cell Polymer Foam Using Low-Load Test Methods
Herring, Helen M.; December 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNL07AA00BTask NNL07AM74T; WBS-510505.03.07.01.07
Report No.(s): NASA/CR-2008-215538; LF99-7926; Copyright; Avail.: CASI: A03, Hardcopy
Various solid polymers, polymer-based composites, and closed-cell polymer foam are being characterized to determine their mechanical properties, using low-load test methods. The residual mechanical properties of these materials after environmental exposure or extreme usage conditions determines their value in aerospace structural applications. In this experimental study, four separate polymers were evaluated to measure their individual mechanical responses after thermal aging and moisture exposure by dynamic mechanical analysis. A ceramic gap filler, used in the gaps between the tiles on the Space Shuttle, was also tested, using dynamic mechanical analysis to determine material property limits during flight. Closed-cell polymer foam, used for the Space Shuttle External Tank insulation, was tested under low load levels to evaluate how the foam's mechanical properties are affected by various loading and unloading scenarios.
Author
MECHANICAL PROPERTIES; CERAMICS; FILLERS; FOAMS; POLYMERS; AGING (MATERIALS); LOAD TESTS; STRUCTURAL DESIGN; TEMPERATURE EFFECTS
20090005180 NASA Dryden Flight Research Center, Edwards, CA, United States
Tests and Techniques for Characterizing and Modeling X-43A Electromechanical Actuators
Lin, Yohan; Baumann, Ethan; Bose, David M.; Beck, Roger; Jenney, Gavin; December 2008; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2008-214637; H-2819; DFRC-434; Copyright; Avail.: CASI: A05, Hardcopy
A series of tests were conducted on the electromechanical actuators of the X-43A research vehicle in preparation for the Mach 7 and 10 hypersonic flights. The tests were required to help validate the actuator models in the simulation and acquire a better understanding of the installed system characteristics. Static and dynamic threshold, multichannel crosstalk, command-to-surface timing, free play, voltage regeneration, calibration, frequency response, compliance, hysteretic damping, and aircraft-in-the-loop tests were performed as part of this effort. This report describes the objectives, configurations, and methods for those tests, as well as the techniques used for developing second-order actuator models from the test results. When the first flight attempt failed because of actuator problems with the launch vehicle, further analysis and model enhancements were performed as part of the return-to-flight activities. High-fidelity models are described, along with the modifications that were required to match measurements taken from the research vehicle. Problems involving the implementation of these models into the X-43A simulation are also discussed. This report emphasizes lessons learned from the actuator testing, simulation modeling, and integration efforts for the X-43A hypersonic research vehicle.
Author
ACTUATORS; FREQUENCY RESPONSE; HYPERSONIC VEHICLES; X-45 AIRCRAFT; RESEARCH VEHICLES; ELECTROMECHANICAL DEVICES; PROVING
20090005181 NASA Dryden Flight Research Center, Edwards, CA, United States
Ground/Flight Correlation of Aerodynamic Loads with Structural Response
Mangalam, Arun S.; Davis, Mark C.; January 05, 2009; In English; 47th AIAA Aerospace Sciences Meeting and Exhibit, 5-8 Jan. 2009, Orlando, FL, United States; Original contains color illustrations
Report No.(s): DFRC-835; Copyright; Avail.: CASI: A03, Hardcopy
Ground and flight tests provide a basis and methodology for in-flight characterization of the aerodynamic and structural performance through the monitoring of the fluid-structure interaction. The NF-15B flight tests of the Intelligent Flight Control System program provided a unique opportunity to test the correlation of aerodynamic loads with points of flow attaching and detaching from the surface, which are also known as flow bifurcation points, as observed in a previous wind tunnel test performed at the U.S. Air Force Academy (Colorado Springs, Colorado). Moreover, flight tests, along with the subsequent unsteady aerodynamic tests in the NASA Transonic Dynamics Tunnel (TDT), provide a basis using surface flow sensors as means of assessing the aeroelastic performance of flight vehicles. For the flight tests, the NF-15B tail was instrumented with hot-film sensors and strain gages for measuring root-bending strains. This data were gathered via selected sideslip maneuvers performed at level flight and subsonic speeds. The aerodynamic loads generated by the sideslip maneuver resulted in a structural response, which were then compared with the hot-film sensor signals. The hot-film sensor signals near the stagnation region were found to be highly correlated with the root-bending strains. For the TDT tests, a flexible wing section developed under the U.S. Air Force Research Lab SensorCraft program was instrumented with strain gages, accelerometers, and hot-film sensors at two span stations. The TDT tests confirmed the correlation between flow bifurcation points and the wing structural response to tunnel-generated gusts. Furthermore, as the wings structural modes were excited by the gusts, a gradual phase change between the flow bifurcation point and the structural mode occurred during a resonant condition.
Author
AERODYNAMIC LOADS; FLIGHT TESTS; GROUND TESTS; UNSTEADY AERODYNAMICS; STRAIN GAGES
20090005183 NASA Johnson Space Center, Houston, TX, United States
Impact Histories of Vesta and Vestoids inferred from Howardites, Eucrites, and Diogenites
Scott, E. R. D.; Bogard, D. D.; Bottke, W. F.; Taylor, G. J.; Greenwood, R. C.; Franchi, I. A.; Keil, K.; Moskovitz, N. A.; Nesvorny, D.; [2009]; In English; 40th Lunar Planetary Conference, 23-27 Mar. 2009, Houston, TX, United States; Original contains color illustrations
Copyright; Avail.: CASI: A01, Hardcopy
The parent body of the howardites, eucrites and diogenites (HEDs) is thought to be asteroid (4) Vesta [1]. However, several eucrites have now been recognized, like NWA 011 and Ibitira, with major element compositions and mineralogy like normal eucrites but with different oxygen isotope compositions and minor element concentrations suggesting they are not from the same body [2, 3]. The discoveries of abnormal eucrites and V-type asteroids that are probably not from Vesta [see 4] raise the question whether the HEDs with normal oxygen isotopes are coming from Vesta [3]. To address this issue and understand more about the evolution of Vesta in preparation for the arrival of the Dawn spacecraft, we integrate fresh insights from Ar-Ar dating and oxygen isotope analyses of HEDs, radiometric dating of differentiated meteorites, as well as dynamical and astronomical studies of Vesta, the Vesta asteroid family (i.e., the Vestoids), and other V-type asteroids.
Author
VESTA ASTEROID; METEORITES; ASTEROIDS; ACHONDRITES; CHRONOLOGY; METEORITIC COMPOSITION
20090005184 NASA Johnson Space Center, Houston, TX, United States
A Process for Comparing Dynamics of Distributed Space Systems Simulations
Cures, Edwin Z.; Jackson, Albert A.; Morris, Jeffery C.; [2009]; In English; Joint 2009 Spring Simkulation Interoperability Workshop (SIW), 23-27 Mar. 2009, San DIego, CA, United States
Copyright; Avail.: CASI: A03, Hardcopy
The paper describes a process that was developed for comparing the primary orbital dynamics behavior between space systems distributed simulations. This process is used to characterize and understand the fundamental fidelities and compatibilities of the modeling of orbital dynamics between spacecraft simulations. This is required for high-latency distributed simulations such as NASA s Integrated Mission Simulation and must be understood when reporting results from simulation executions. This paper presents 10 principal comparison tests along with their rationale and examples of the results. The Integrated Mission Simulation (IMSim) (formerly know as the Distributed Space Exploration Simulation (DSES)) is a NASA research and development project focusing on the technologies and processes that are related to the collaborative simulation of complex space systems involved in the exploration of our solar system. Currently, the NASA centers that are actively participating in the IMSim project are the Ames Research Center, the Jet Propulsion Laboratory (JPL), the Johnson Space Center (JSC), the Kennedy Space Center, the Langley Research Center and the Marshall Space Flight Center. In concept, each center participating in IMSim has its own set of simulation models and environment(s). These simulation tools are used to build the various simulation products that are used for scientific investigation, engineering analysis, system design, training, planning, operations and more. Working individually, these production simulations provide important data to various NASA projects.
Author
AEROSPACE SYSTEMS; SYSTEMS ENGINEERING; COMPUTERIZED SIMULATION; COMPLEX SYSTEMS
20090005185 NASA Johnson Space Center, Houston, TX, United States; United Space Alliance, Houston, TX, United States
Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Techniques
Goodman, John L.; Walker, Stephen R.; January 31, 2009; In English; 32nd Annual AAS Guidance and Control Conference, 31 Jan. - 4 Feb. 2009, Breckenridge, CO, United States; Original contains color and black and white illustrations
Report No.(s): AAS 09-013; Copyright; Avail.: CASI: A03, Hardcopy
Hubble Space Telescope (HST) servicing, performed by Space Shuttle crews, has contributed to what is arguably one of the most successful astronomy missions ever flown. Both nominal and contingency proximity operations techniques were developed to enable successful servicing, while lowering the risk of damage to HST systems, and improve crew safety. Influencing the development of these techniques were the challenges presented by plume impingement and HST performance anomalies. The design of both the HST and the Space Shuttle was completed before the potential of HST contamination and structural damage by shuttle RCS jet plume impingement was fully understood. Relative navigation during proximity operations has been challenging, as HST was not equipped with relative navigation aids. Since HST reached orbit in 1990, proximity operations design for servicing missions has evolved as insight into plume contamination and dynamic pressure has improved and new relative navigation tools have become available. Servicing missions have provided NASA with opportunities to gain insight into servicing mission design and development of nominal and contingency procedures. The HST servicing experiences and lessons learned are applicable to other programs that perform on-orbit servicing and rendezvous, both human and robotic.
Author
HUBBLE SPACE TELESCOPE; MAINTENANCE; SPACEBORNE TELESCOPES; ROBOTICS; NAVIGATION AIDS; DYNAMIC PRESSURE; SPACECREWS; SPACE SHUTTLES
20090005186 NASA Dryden Flight Research Center, Edwards, CA, United States
CFD Analysis of Nozzle Jet Plume Effects on Sonic Boom Signature
Bui, Trong T.; January 05, 2009; In English; 47th AIAA Aerospace Sciences Meeting, 5-8 Jan. 2009, Orlando, FL, FROM; Original contains color and black and white illustrations
Report No.(s): DFRC-843; AIAA Paper 2009-1054; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005186
An axisymmetric full Navier-Stokes computational fluid dynamics study is conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock research airplane, is considered. The computational fluid dynamics code is validated using available wind-tunnel sonic boom experimental data. The effects of grid size, spatial order of accuracy, grid type, and flow viscosity on the accuracy of the predicted sonic boom pressure signature are quantified. Grid lines parallel to the Mach wave direction are found to give the best results. Second-order accurate upwind methods are required as a minimum for accurate sonic boom simulations. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature is observed for the highly underexpanded nozzle flow. Axisymmetric computational fluid dynamics simulations show the flow physics inside the F-15 nozzle to be nonisentropic and complex. Although the one-dimensional isentropic nozzle plume results look reasonable, they fail to capture the sonic boom shock train in the highly underexpanded nozzle flow.
Author
COMPUTATIONAL FLUID DYNAMICS; PLUMES; NOZZLE FLOW; GAS JETS; SONIC BOOMS; SIGNATURES; NOZZLE GEOMETRY; COMPUTATIONAL GRIDS
20090005210 Eltron Research, Inc., Boulder, CO United States
Polymer composites containing nanotubes
Bley, Richard A., Inventor; August 12, 2008; In English
Contract(s)/Grant(s): NAS9-00116; NAS9-00028
Patent Info.: August 25, 2004US-Patent-7,411,019; US-Patent-Appl-SN-10/927,628
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005210
The present invention relates to polymer composite materials containing carbon nanotubes, particularly to those containing singled-walled nanotubes. The invention provides a polymer composite comprising one or more base polymers, one or more functionalized m-phenylenevinylene-2,5-disubstituted-p-phenylenevinylene polymers and carbon nanotubes. The invention also relates to functionalized m-phenylenevinylene-2,5-disubstituted-p-phenylenevinylene polymers, particularly to m-phenylenevinylene-2,5-disubstituted-p-phenylenevinylene polymers having side chain functionalization, and more particularly to m-phenylenevinylene-2,5-disubstituted-p-phenylenevinylene polymers having olefin side chains and alkyl epoxy side chains. The invention further relates to methods of making polymer composites comprising carbon nanotubes.
Official Gazette of the U.S. Patent and Trademark Office
CARBON NANOTUBES; COMPOSITE MATERIALS; POLYMER MATRIX COMPOSITES; POLYMERS
20090005211 NASA, Washington, DC United States
Guidance and control for an autonomous soaring UAV
Allen, Michael J., Inventor; October 7, 2008; In English
Patent Info.: March 23, 2006US-Patent-7,431,243; US-Patent-Appl-SN-11/277,325
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005211
The present invention provides a practical method for UAVs to take advantage of thermals in a manner similar to piloted aircrafts and soaring birds. In general, the invention is a method for a UAV to autonomously locate a thermal and be guided to the thermal to greatly improve range and endurance of the aircraft.
Official Gazette of the U.S. Patent and Trademark Office
AUTONOMY; SOARING; AIRCRAFT GUIDANCE; PILOTLESS AIRCRAFT; UNMANNED AIRCRAFT SYSTEMS; AIR CURRENTS
20090005212 SunPower, Inc., Athens, OH United States
Pulse tube cooler having 1/4 wavelength resonator tube instead of reservoir
Gedeon, David R., Inventor; October 14, 2008; In English
Contract(s)/Grant(s): NAS5-02021
Patent Info.: August 23, 2005US-Patent-7,434,409; US-Patent-Appl-SN-11/209,984
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005212
An improved pulse tube cooler having a resonator tube connected in place of a compliance volume or reservoir. The resonator tube has a length substantially equal to an integer multiple of 1/4 wavelength of an acoustic wave in the working gas within the resonator tube at its operating frequency, temperature and pressure. Preferably, the resonator tube is formed integrally with the inertance tube as a single, integral tube with a length approximately 1/2 of that wavelength. Also preferably, the integral tube is spaced outwardly from and coiled around the connection of the regenerator to the pulse tube at a cold region of the cooler and the turns of the coil are thermally bonded together to improve heat conduction through the coil.
Official Gazette of the U.S. Patent and Trademark Office
CRYOGENIC COOLING; CRYOGENIC EQUIPMENT; CRYOGENICS; RESONATORS
Additions to the NASA Aeronautics and Space Database as of 02/13/2009
20090005237 International Trade Bridge, Inc., Beavercreek, OH, United States; NASA Kennedy Space Center, Cocoa Beach, FL, United States
Final Report on NASA Portable Laser Coating Removal Systems Field Demonstrations and Testing
Rothgeb, Matthew J; McLaughlin, Russell L.; May 2008; In English; CD-ROM contains full text document in PDF format
Contract(s)/Grant(s): NNH06CC40C
Report No.(s): NASA/CR-2008-214752; Copyright; Avail.: CASI: C01, CD-ROM: A04, Hardcopy
Processes currently used throughout the National Aeronautics and Space Administration (NASA) to remove corrosion and coatings from structures, ground service equipment, small parts and flight components result in waste streams consisting of toxic chemicals, spent media blast materials, and waste water. When chemicals are used in these processes they are typically high in volatile organic compounds (VOC) and are considered hazardous air pollutants (HAP). When blast media is used, the volume of hazardous waste generated is increased significantly. Many of the coatings historically used within NASA contain toxic metals such as hexavalent chromium, and lead. These materials are highly regulated and restrictions on worker exposure continue to increase. Most recently the Occupational Safety and Health Administration (OSHA) reduced the permissible exposure limit (PEL) for hexavalent chromium (CrVI) from 52 to 5 micrograms per cubic meter of air as an 8-hour time-weighted average. Hexavalent chromium is found in numerous pretreatment and primer coatings used within the Space Shuttle Program. In response to the need to continue to protect assets within the agency and the growing concern over these new regulations, NASA is researching different ways to continue the required maintenance of both facility and flight equipment in a safe, efficient, and environmentally preferable manner. The use of laser energy to prepare surfaces for a variety of processes, such as corrosion and coating removal, weld preparation, and non destructive evaluation (NDE) is a relatively new application of the technology that has been proven to be environmentally preferable and in many cases less labor intensive than currently used removal methods. The novel process eliminates VOCs and blast media and captures the removed coatings with an integrated vacuum system. This means that the only waste generated are the coatings that are removed, resulting in an overall cleaner process. The development of a Portable Laser Coating Removal System (PLCRS) started as the goal of a Joint Group on Pollution Prevention (JG-PP) project, led by the Air Force, where several types of lasers in several configurations were thoroughly evaluated. Following this project, NASA decided to evaluate the best performers on processes and coatings specific to the agency. Laser systems used during this project were all of a similar design, between 40 and 500 Watts, most of which had integrated vacuum systems in order to collect materials removed from substrate surfaces during operation.
Derived from text
COATING; CORROSION; POLLUTION CONTROL; LASERS; PORTABLE EQUIPMENT; AIR POLLUTION
20090005240 NASA Johnson Space Center, Houston, TX, United States
Reliability of Strength Testing using the Advanced Resistive Exercise Device and Free Weights
English, Kirk L.; Loehr, James A.; Laughlin, Mitzi A.; Lee, Stuart M. C.; Hagan, R. Donald; [2008]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
The Advanced Resistive Exercise Device (ARED) was developed for use on the International Space Station as a countermeasure against muscle atrophy and decreased strength. This investigation examined the reliability of one-repetition maximum (1RM) strength testing using ARED and traditional free weight (FW) exercise. Methods: Six males (180.8 +/- 4.3 cm, 83.6 +/- 6.4 kg, 36 +/- 8 y, mean +/- SD) who had not engaged in resistive exercise for at least six months volunteered to participate in this project. Subjects completed four 1RM testing sessions each for FW and ARED (eight total sessions) using a balanced, randomized, crossover design. All testing using one device was completed before progressing to the other. During each session, 1RM was measured for the squat, heel raise, and deadlift exercises. Generalizability (G) and intraclass correlation coefficients (ICC) were calculated for each exercise on each device and were used to predict the number of sessions needed to obtain a reliable 1RM measurement (G . 0.90). Interclass reliability coefficients and Pearson's correlation coefficients (R) also were calculated for the highest 1RM value (1RM9sub peak)) obtained for each exercise on each device to quantify 1RM relationships between devices.
Author
CORRELATION COEFFICIENTS; PHYSICAL EXERCISE; MUSCLES; PERFORMANCE TESTS; MUSCULAR STRENGTH
20090005244 NASA Goddard Space Flight Center, Greenbelt, MD, United States
GFO and JASON Altimeter Engineering Assessment Report. Update: GFO--Acceptance to December 27, 2007, JASON--Acceptance to December 26, 2007. Version 1: June 2008
Conger, A. M.; Hancock, D. W.; Hayne, G. S.; Brooks, R. L.; September 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG06HX14C
Report No.(s): NASA/TM-2008-209984/Ver.1/Vol.10; 200802408; Copyright; Avail.: CASI: A09, Hardcopy
The purpose of this document is to present and document GEOSAT Follow-On (GFO) performance analyses and results. This is the eighth Assessment Report since the initial report. This report extends the performance assessment since acceptance to 27 December 2007. Since launch, a variety of GFO performance studies have been performed: Appendix A provides an accumulative index of those studies. We began the inclusion of analyses of the JASON altimeter after the end of the Topographic Experiment (TOPEX) mission. Prior to this, JASON and TOPEX were compared during our assessment of theTOPEX altimeter. With the end of the TOPEX mission, we developed methods to report on JASON as it relates to GFO.
Author
GEOSAT SATELLITES; ALTIMETERS; LAUNCHING
Additions to the NASA Aeronautics and Space Database as of 02/16/2009
20090005254 Boeing Co., Chicago, IL United States
Parametrically disciplined operation of a vibratory gyroscope
Shcheglov, Kirill V., Inventor; Hayworth, Ken J., Inventor; Challoner, A. Dorian, Inventor; Peay, Chris S., Inventor; October 14, 2008; In English
Contract(s)/Grant(s): NAS7-1402
Patent Info.: July 29, 2005US-Patent-7,437,253; US-Patent-Appl-SN-11/192,759
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005254
Parametrically disciplined operation of a symmetric nearly degenerate mode vibratory gyroscope is disclosed. A parametrically-disciplined inertial wave gyroscope having a natural oscillation frequency in the neighborhood of a sub-harmonic of an external stable clock reference is produced by driving an electrostatic bias electrode at approximately twice this sub-harmonic frequency to achieve disciplined frequency and phase operation of the resonator. A nearly symmetric parametrically-disciplined inertial wave gyroscope that can oscillate in any transverse direction and has more than one bias electrostatic electrode that can be independently driven at twice its oscillation frequency at an amplitude and phase that disciplines its damping to zero in any vibration direction. In addition, operation of a parametrically-disciplined inertial wave gyroscope is taught in which the precession rate of the driven vibration pattern is digitally disciplined to a prescribed non-zero reference value.
Official Gazette of the U.S. Patent and Trademark Office
PARAMETERIZATION; GYROSCOPES; VIBRATION
20090005255 Honeywell International, Inc., Morristown, NJ United States
Systems and methods for self-synchronized digital sampling
Samson, Jr., John R., Inventor; October 14, 2008; In English
Contract(s)/Grant(s): NAS8-01140
Patent Info.: November 1, 2005US-Patent-7,437,272; US-Patent-Appl-SN-11/264,566
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005255
Systems and methods for self-synchronized data sampling are provided. In one embodiment, a system for capturing synchronous data samples is provided. The system includes an analog to digital converter adapted to capture signals from one or more sensors and convert the signals into a stream of digital data samples at a sampling frequency determined by a sampling control signal; and a synchronizer coupled to the analog to digital converter and adapted to receive a rotational frequency signal from a rotating machine, wherein the synchronizer is further adapted to generate the sampling control signal, and wherein the sampling control signal is based on the rotational frequency signal.
Official Gazette of the U.S. Patent and Trademark Office
DATA SAMPLING; SYNCHRONISM; PULSE COMMUNICATION
20090005801 SunPower, Inc., Athens, OH United States
Multi-stage pulse tube cryocooler with acoustic impedance constructed to reduce transient cool down time and thermal loss
Gedeon, David R., Inventor; Wilson, Kyle B., Inventor; October 21, 2008; In English
Contract(s)/Grant(s): NAS5-02021
Patent Info.: August 23, 2005US-Patent-7,437,878; US-Patent-Appl-SN-11/209,983
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005801
The cool down time for a multi-stage, pulse tube cryocooler is reduced by configuring at least a portion of the acoustic impedance of a selected stage, higher than the first stage, so that it surrounds the cold head of the selected stage. The surrounding acoustic impedance of the selected stage is mounted in thermally conductive connection to the warm region of the selected stage for cooling the acoustic impedance and is fabricated of a high thermal diffusivity, low thermal radiation emissivity material, preferably aluminum.
Official Gazette of the U.S. Patent and Trademark Office
ACOUSTIC IMPEDANCE; CRYOGENIC COOLING; FABRICATION; LOSSES; THERMAL DIFFUSIVITY
20090005802 NASA, Washington, DC United States
Actuator operated microvalves
Okojie, Robert S., Inventor; October 21, 2008; In English
Patent Info.: August 26, 2005US-Patent-7,438,030; US-Patent-Appl-SN-11/213,604
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005802
An actuator operated microvalve and the method of making same is disclosed and claimed. The microvalve comprises a SiC housing which includes a first lower portion and a second upper portion. The lower portion of the SiC housing includes a passageway therethrough, a microvalve seat, and a moveable SiC diaphragm. The SiC diaphragm includes a centrally located boss and radially extending corrugations which may be sinusoidally shaped. The boss of the SiC diaphragm moves and modulates in a range of positions between a closed position wherein the boss interengages said microvalve seat prohibiting communication of fluid through the passageway and a fully open position when the boss is spaced apart from the seat at its maximum permitting communication of fluid through said passageway. The actuator includes a SiC top plate affixed to the boss of the diaphragm and a first electrode and the second upper portion of the SiC housing further includes a second electrode.
Official Gazette of the U.S. Patent and Trademark Office
ACTUATORS; VALVES; SILICON CARBIDES
20090005852 NASA Kennedy Space Center, Cocoa Beach, FL, United States
Volume Averaged Height Integrated Radar Reflectivity (VAHIRR) Cost-Benefit Analysis
Bauman, William H., III; October 2008; In English; Original contains color illustrations
Contract(s)/Grant(s): NNK06MA70C
Report No.(s): NASA/CR-2008-214753; Copyright; Avail.: CASI: A03, Hardcopy
Lightning Launch Commit Criteria (LLCC) are designed to prevent space launch vehicles from flight through environments conducive to natural or triggered lightning and are used for all U.S. government and commercial launches at government and civilian ranges. They are maintained by a committee known as the NASA/USAF Lightning Advisory Panel (LAP). The previous LLCC for anvil cloud, meant to avoid triggered lightning, have been shown to be overly restrictive. Some of these rules have had such high safety margins that they prohibited flight under conditions that are now thought to be safe 90% of the time, leading to costly launch delays and scrubs. The LLCC for anvil clouds was upgraded in the summer of 2005 to incorporate results from the Airborne Field Mill (ABFM) experiment at the Eastern Range (ER). Numerous combinations of parameters were considered to develop the best correlation of operational weather observations to in-cloud electric fields capable of rocket triggered lightning in anvil clouds. The Volume Averaged Height Integrated Radar Reflectivity (VAHIRR) was the best metric found. Dr. Harry Koons of Aerospace Corporation conducted a risk analysis of the VAHIRR product. The results indicated that the LLCC based on the VAHIRR product would pose a negligible risk of flying through hazardous electric fields. Based on these findings, the Kennedy Space Center Weather Office is considering seeking funding for development of an automated VAHIRR algorithm for the new ER 45th Weather Squadron (45 WS) RadTec 431250 weather radar and Weather Surveillance Radar-1988 Doppler (WSR-88D) radars. Before developing an automated algorithm, the Applied Meteorology Unit (AMU) was tasked to determine the frequency with which VAHIRR would have allowed a launch to safely proceed during weather conditions otherwise deemed "red" by the Launch Weather Officer. To do this, the AMU manually calculated VAHIRR values based on candidate cases from past launches with known anvil cloud LLCC violations. An automated algorithm may be developed if the analyses from past launches show VAHIRR would have provided a significant cost benefit by allowing a launch to proceed. The 45 WS at the ER and 30th Weather Squadron (30 WS) at the Western Range provided the AMU with launch weather summaries from past launches that were impacted by LLCC. The 45 WS provided summaries from 14 launch attempts and the 30 WS fkom 5. The launch attempts occurred between December 2001 and June 2007. These summaries helped the AMU determine when the LLCC were "red" due to anvil cloud. The AMU collected WSR-88D radar reflectivity, cloud-to-ground lightning strikes, soundings and satellite imagery. The AMU used step-by-step instructions for calculating VAHIRR manually as provided by the 45 WS. These instructions were used for all of the candidate cases when anvil cloud caused an LLCC violation identified in the launch weather summaries. The AMU evaluated several software programs capable of visualizing radar data so that VAHIRR could be calculated and chose GR2Analyst from Gibson Ridge Software, LLC. Data availability and lack of detail from some launch weather summaries permitted analysis of six launch attempts from the ER and none from the WR. The AMU did not take into account whether or not other weather LCC violations were occurring at the same time as the anvil cloud LLCC since the goal of this task was to determine how often VAHIRR provided relief to the anvil cloud LLCC at any time during several previous launch attempts. Therefore, in the statistics presented in this report, it is possible that even though VAHIRR provided relief to the anvil cloud LLCC, other weather LCC could have been violated not permitting the launch to proceed. The results of this cost-benefit analysis indicated VAHIRR provided relief from the anvil cloud LLCC between about 15% and 18% of the time for varying 5-minute time periods based on summaries fkom six launch attempts and would have allowed launch to proceed that were otherwise "NO GO" due to the anvil cloud LLCC if the T-0 time occurred during the anvil cloud LLCC violations.
Derived from text
FLIGHT CONDITIONS; LIGHTNING; REFLECTANCE; SPACECRAFT LAUNCHING; WEATHER FORECASTING; METEOROLOGICAL RADAR; LAUNCH WINDOWS
20090005854 NASA, Washington, DC United States
Method and associated apparatus for capturing, servicing and de-orbiting earth satellites using robotics
Cepollina, Frank J., Inventor; Burns, Richard D., Inventor; Holz, Jill M., Inventor; Corbo, James E., Inventor; Jedhrich, Nicholas M., Inventor; October 21, 2008; In English
Patent Info.: February 2, 2007US-Patent-7,438,264; US-Patent-Appl-SN-11/670,781
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005854
This invention is a method and supporting apparatus for autonomously capturing, servicing and de-orbiting a free-flying spacecraft, such as a satellite, using robotics. The capture of the spacecraft includes the steps of optically seeking and ranging the satellite using LIDAR; and matching tumble rates, rendezvousing and berthing with the satellite. Servicing of the spacecraft may be done using supervised autonomy, which is allowing a robot to execute a sequence of instructions without intervention from a remote human-occupied location. These instructions may be packaged at the remote station in a script and uplinked to the robot for execution upon remote command giving authority to proceed. Alternately, the instructions may be generated by Artificial Intelligence (AI) logic onboard the robot. In either case, the remote operator maintains the ability to abort an instruction or script at any time, as well as the ability to intervene using manual override to teleoperate the robot.In one embodiment, a vehicle used for carrying out the method of this invention comprises an ejection module, which includes the robot, and a de-orbit module. Once servicing is completed by the robot, the ejection module separates from the de-orbit module, leaving the de-orbit module attached to the satellite for de-orbiting the same at a future time. Upon separation, the ejection module can either de-orbit itself or rendezvous with another satellite for servicing. The ability to de-orbit a spacecraft further allows the opportunity to direct the landing of the spent satellite in a safe location away from population centers, such as the ocean.
Official Gazette of the U.S. Patent and Trademark Office
AUTONOMY; ORBITAL RENDEZVOUS; ROBOTICS; SPACECRAFT MAINTENANCE; SPACECRAFT REENTRY
20090005855 NASA, Washington, DC United States
Simplified night sky display system
Castellano, Timothy P., Inventor; October 21, 2008; In English
Patent Info.: January 18, 2006US-Patent-7,438,422; US-Patent-Appl-SN-11/340,816
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005855
A portable structure, simply constructed with inexpensive and generally lightweight materials, for displaying a selected portion of the night sky and selected planets, satellites, comets and other astronomically observable objects that are visually perceptible within that portion of the night sky. The structure includes a computer having stored signals representing the observable objects, an image projector that converts and projects the stored signals as visually perceptible images, a first curvilinear light-reflecting surface to receive and reflect the visually perceptible images, and a second curvilinear surface to receive and display the visually perceptible images reflected from the first surface. The images may be motionless or may move with passage of time. In one embodiment, the structure includes an inflatable screen surface that receives gas in an enclosed volume, supports itself without further mechanical support, and optionally self-regulates pressure of the received gas within the enclosed volume.
Official Gazette of the U.S. Patent and Trademark Office
DISPLAY DEVICES; NIGHT SKY; PROJECTORS; PLANETARIUMS; ASTRONOMICAL MODELS
20090005856 City Univ. of New York, NY United States
Tetravalent chromium doped laser materials and NIR tunable lasers
Alfano, Robert R., Inventor; Petricevic, Vladimir, Inventor; Bykov, Alexey, Inventor; October 21, 2008; In English
Contract(s)/Grant(s): NCC1-03009
Patent Info.: December 7, 2005US-Patent-7,440,480; US-Patent-Appl-SN-11/295,749
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005856
A method is described to improve and produce purer Cr.sup.4+-doped laser materials and lasers with reduced co-incorporation of chromium in any other valence states, such as Cr.sup.3+, Cr.sup.2+, Cr.sup.5+, and Cr.sup.6+. The method includes: 1) certain crystals of olivine structure with large cation (Ca) in octahedral sites such as Cr.sup.4+:Ca.sub.2GeO.sub.4, Cr.sup.4+:Ca.sub.2SiO.sub.4, Cr.sup.4+:Ca.sub.2Ge.sub.xSi.sub.1-xO.sub.4 (where 0<x<1), and/or 2) high-temperature solution growth techniques that enable the growth of the crystals below the temperature of polymorphic transitions by using low melting point solvent based on oxide, fluoride and/or chloride compounds. Purer Cr.sup.4+-doped laser materials are characterized by a relatively high concentration of Cr.sup.4+-lasing ion in crystalline host that makes these materials suitable for compact high power (thin disk/wedge) NIR laser applications.
Official Gazette of the U.S. Patent and Trademark Office
ADDITIVES; CHROMIUM; LASER MATERIALS; LASERS; TUNABLE LASERS
20090005857 International Trade Bridge, Inc., Cocoa Beach, FL, United States; International Trade Bridge, Inc., Beavercreek, OH, United States; NASA Kennedy Space Center, Cocoa Beach, FL, United States
Final Report on Portable Laser Coating Removal Systems Field Demonstrations and Testing
Rothgeb, Matthew J.; McLaughlin, Russell L.; May 2008; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNH06CC40C
Report No.(s): NASA CR-2008-214754; NASA.PROJ.PLCRS.FTR.MR.01May08.F; Copyright; Avail.: CASI: A04, Hardcopy
Processes currently used throughout the National Aeronautics and Space Administration (NASA) to remove corrosion and coatings from structures, ground service equipment and small components results in waste streams consisting of toxic chemicals, spent media blast materials, and waste water. When chemicals are used in these processes they are typically high in volatile organic compounds (VOC) and are considered hazardous air pollutants (HAP). When blast media is used, the volume of hazardous waste generated is increased significantly. Many of the coatings historically used within NASA contain toxic metals such as hexavalent chromium, and lead. These materials are highly regulated and restrictions on worker exposure continue to increase. Most recently the EPA reduced the permissible exposure limit (PEL) for hexavalent chromium. The new standard lowers OSHA's PEL for hexavalent chromium from 52 to 5 micrograms of Cr(V1) per cubic meter of air as an 8-hour time-weighted average. Hexavalent chromium is found in the pretreatment and primer coatings used within the Shuttle Program. In response to the need to continue to protect assets within the agency and the growing concern over these new regulations, NASA is researching different ways to continue the required maintenance of both facility and flight equipment in a safe, efficient and environmentally preferable manner. The use of laser energy to remove prepare surfaces for a variety of processes, such as corrosion and coating removal, weld preparation and non destructive evaluation is a relatively new technology that has shown itself to be environmentally preferable and in many cases less labor intensive than currently used removal methods. The development of a Portable Laser Coating Removal System (PLCRS) started as the goal of a Joint Group on Pollution Prevention (JG-PP) project, led by the Air Force, where several types of lasers in several configurations were thoroughly evaluated. Following this project, NASA decided to evaluate the best performers on processes and coatings specific to the agency. Laser systems used during this project were all of a similar design, most of which had integrated vacuum systems in order to collect materials removed from substrate surfaces during operation. Due to the fact that the technology lends itself to a bide variety of processes, several site demonstrations were organized in order to allow for greater evaluation of the laser systems across NASA. The project consisted of an introductory demonstration and a more in-depth evaluation at Wright-Patterson Air Force Base. Additionally, field demonstrations occurred at Glenn Research Center and Kennedy Space Center. During these demonstrations several NASA specific applications were evaluated, including the removal of coatings within Orbiter tile cavities and Teflon from Space Shuttle Main Engine gaskets, removal of heavy grease from Solid Rocket Booster components and the removal of coatings on weld lines for Shuttle and general ground service equipment for non destructive evaluation (NDE). In addition, several general industry applications such as corrosion removal, structural coating removal, weld-line preparation and surface cleaning were evaluated. This included removal of coatings and corrosion from surfaces containing lead-based coatings and applications similar to launch-structure maintenance and Crawler maintenance. During the project lifecycle, an attempt was made to answer process specific concerns and questions as they arose. Some of these initially unexpected questions concerned the effects lasers might have on substrates used on flight equipment including strength, surface re-melting, substrate temperature and corrosion resistance effects. Additionally a concern was PPE required for operating such a system including eye, breathing and hearing protection. Most of these questions although not initially planned, were fully explored as a part of this project. Generally the results from tesng were very positive. Corrosion was effectively removed from steel, but less successfully from aluminum alloys. Coatings were able to be removed, with varying results, generally dark, matte and thin coatings were easier to remove. Steel and aluminum panels were able to be cleaned for welding, with no known deleterious effects and weld-lines were able to have coatings removed in critical areas for NDE while saving time as compared to other methods.
Derived from text
CORROSION; LASERS; MAINTENANCE; LASER APPLICATIONS; PAINT REMOVAL
20090005858 Kentucky Univ., Lexington, KY United States
System and technique for retrieving depth information about a surface by projecting a composite image of modulated light patterns
Hassebrook, Laurence G., Inventor; Lau, Daniel L., Inventor; Guan, Chun, Inventor; October 21, 2008; In English
Contract(s)/Grant(s): NCC5-222
Patent Info.: May 21, 2003US-Patent-7,440,590; US-Patent-Appl-SN-10/444,033
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005858
A technique, associated system and program code, for retrieving depth information about at least one surface of an object. Core features include: projecting a composite image comprising a plurality of modulated structured light patterns, at the object; capturing an image reflected from the surface; and recovering pattern information from the reflected image, for each of the modulated structured light patterns. Pattern information is preferably recovered for each modulated structured light pattern used to create the composite, by performing a demodulation of the reflected image. Reconstruction of the surface can be accomplished by using depth information from the recovered patterns to produce a depth map/mapping thereof. Each signal waveform used for the modulation of a respective structured light pattern, is distinct from each of the other signal waveforms used for the modulation of other structured light patterns of a composite image; these signal waveforms may be selected from suitable types in any combination of distinct signal waveforms, provided the waveforms used are uncorrelated with respect to each other. The depth map/mapping to be utilized in a host of applications, for example: displaying a 3-D view of the object; virtual reality user-interaction interface with a computerized device; face--or other animal feature or inanimate object--recognition and comparison techniques for security or identification purposes; and 3-D video teleconferencing/telecollaboration.
Official Gazette of the U.S. Patent and Trademark Office
IMAGE PROCESSING; PATTERN RECOGNITION; PHOTOMAPPING; IMAGE CLASSIFICATION; IMAGE ANALYSIS
20090005860 California Inst. of Tech., Pasadena, CA United States
Single mode whispering-gallery-mode resonator
Savchenkov, Anatoliy, Inventor; Strekalov, Dmitry V., Inventor; Matsko, Andrey B., Inventor; Ilchenko, Vladimir, Inventor; Maleki, Lutfollah, Inventor; October 21, 2008; In English
Patent Info.: November 17, 2005US-Patent-7,440,651; US-Patent-Appl-SN-11/282,160
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005860
Whispering-gallery-mode (WGM) resonators configured to support only a single whispering gallery mode.
Official Gazette of the U.S. Patent and Trademark Office
RESONATORS; WHISPERING GALLERY MODES; Q FACTORS; RESONANT VIBRATION
20090005863 California Inst. of Tech., Pasadena, CA United States
Organic fuel cell methods and apparatus
Vamos, Eugene, Inventor; Surampudi, Subbarao, Inventor; Narayanan, Sekharipuram R., Inventor; Frank, Harvey A., Inventor; Halpert, Gerald, Inventor; Olah, George A., Inventor; Prakash, G. K. Surya, Inventor; November 4, 2008; In English
Patent Info.: May 27, 2004US-Patent-7,445,859; US-Patent-Appl-SN-10/857,587
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005863
A liquid organic, fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.
Official Gazette of the U.S. Patent and Trademark Office
CELL ANODES; CELL CATHODES; METHYL ALCOHOL; BIOCHEMICAL FUEL CELLS
20090005864 California Univ., Oakland, CA United States
Fluid control structures in microfluidic devices
Mathies, Richard A., Inventor; Grover, William H., Inventor; Skelley, Alison, Inventor; Lagally, Eric, Inventor; Liu, Chung N., Inventor; November 4, 2008; In English
Contract(s)/Grant(s): NAG5-9659
Patent Info.: December 29, 2003US-Patent-7,445,926; US-Patent-Appl-SN-10/750,533
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090005864
Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.
Official Gazette of the U.S. Patent and Trademark Office
CONTROL EQUIPMENT; ELASTOMERS; MICROFLUIDIC DEVICES; MICROINSTRUMENTATION; MEMBRANES
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