Mission Name: STS-69 (71) Endeavour (9) Pad 39-A (55) 71st Shuttle Mission 102nd US Manned Mission 9th Flight OV-105 30th Shuttle EVA 10th Rollback NOTE: Click Here for Countdown Homepage Crew: David M. Walker (4), Commander Kenneth D. Cockrell (2), Pilot James S. Voss (3), Payload Commander James H. Newman Ph.D.(2), Mission Specialist 2 Michael L. Gernhardt (1), Mission Specialist 3 Milestones: OPF -- 3/28/95 VAB -- 6/28/95 PAD -- 7/05/95 (Rollback) VAB -- 08/1/95 PAD -- 08/8/95 (Reference KSC Shuttle Status Jul 1995) (Reference KSC Shuttle Status Aug 1995) (Reference KSC Shuttle Status Sep 1995) Payload: SPARTAN 201-03, WSF-2, IEH-01, CAPL-02/GBA, EDFT-02, MSX-02, STL/NIH-C-04, CGBA-03, BRIC-06, EPICS, CMIX-04, G-726 Mission Objectives: The 11-day mission will feature the second flight of the Wake Shield Facility (WSF), a saucer-shaped satellite that will fly free of the Shuttle for several days. The WSF will grow thin films in a near perfect vacuum created by the wake of the satellite as it it moves through space. The crew also will deploy and retrieve the Spartan 201 astronomy satellite, perform a six-hour spacewalk to test assembly techniques for the international Space Station and test thermal improvements made to space suits used during space walks. The Spartan 201 free-flyer will be making its third flight aboard the Shuttle. The Spartan 201 mission is a scientific research effort aimed at the investigation of the interaction between the Sun and its outflowing wind of charged particles. Spartan's goal is to study the outer atmosphere of the Sun and its transition into the solar wind that constantly flows past the Earth. STS-69 will see the first flight of the International Extreme Ultraviolet Hitchhiker (IEH-1), the first of five planned flights to measure and monitor long-term variations in the magnitude of absolute extreme ultraviolet (EUV) flux coming from the Sun, and to study EUV emissions from the plasma torus system around Jupiter originating from its moon Io. Also flying aboard Endeavour will be the combined Capillary Pumped Loop-2/Gas Bridge Assembly (CAPL-2/GBA) payload. This experiment consists of the CAPL-2 Hitchhiker payload designed as an in-orbit microgravity demonstration of a cooling system planned for the Earth Observing System Program and the Thermal Energy Storage-2 payload, part of an effort to develop advanced energy generation techniques. Also a part of this payload are several Get Away Special (GAS) experiments which will investigate areas such as the interaction of spacecraft attitude and orbit control systems with spacecraft structures, fluid-filled beams as structural dampers in space and the effects of smoldering combustion in a long-term microgravity environment. Another payload being flown with a connection to the development of the Space Station is the Electrolysis Performance Improvement Concept Study (EPICS). Supply of oxygen and hydrogen by electrolyzing water in space will play an important role in meeting NASA's needs and goals for future space missions. On-board generation of oxygen is expected to reduce the annual resupply requirement for the Space Station by approximately 12,000 pounds. Other payloads aboard are the National Institutes of Health- Cells-4 (NIH-C4) experiment that investigates bone loss during space flight; the Biological Research in Canister-6 (BRIC-6) that studies the gravity-sensing mechanism within mammalian cells. Also flying are two commercial experiments. (CMIX-4) whose objectives include analysis of cell change in microgravity along with studies of neuro-muscular development disorders and the Commercial Generic Bioprocessing Apparatus-7 (CGBA-7). CGBA is a secondary payload that serves as an incubator and data collection point for experiments in pharmaceuticals testing and biomedicine, bioprocessing and biotechnology, agriculture and the environment. The Thermal Energy Storage (TES-2) experiment also is part of the CAPL-2/GBA-6. The TES-2 payload is designed to provide data for understanding the long-duration behavior of thermal energy storage fluoride salts that undergo repeated melting and freezing in microgravity. The TES-2 payload is designed to study the microgravity behavior of voids in Lithium Fluoride-Calcium Fluoride eutectic, a thermal energy storage salt. Data from this experiment will validate a computer code called TESSIM, useful for the analysis of heat receivers in advanced solar dynamic power system designs. Launch: Thursday, September 7 at 11:09:00.052 am EDT. The launch window was 2 hours 30 min. Solid Rocket Boosters (SRB's) seperation successful. At 7min 45sec SSME throttled back while Endeavour traveling at more than 4miles per sec and 640 miles downrange. SSME cutoff confirmed at 8min 30sec. Operations to load the External Tank began at 2:20am 9/7/95 and were completed at 5:15am. The crew suited up at 7:30am EDT and left the Operations and Checkout Building (O&C) at 7:58am EDT. The crew arrived at launch Pad 39-A at 8:10am EDT. The hatch was closed and sealed but failed to pass its leak check at 9:50am EDT. The crew hatch was reopened and the seals checked. Then a retest was performed. Another problem late in the count was with Water Spray Boiler # 2. The Water Spray Boilers normally pressurize to 39 PSI but unit #2 showed a pressure of 38.7 PSI. This did not violate any Launch Commit Criteria and the Mission Management Team determined the lower pressure was not a constraint to launch. Also, there was a minor problem with a "safe" talkback indicator on a safe and arm device on the Solid Rocket Booster. This problem has been seen before and is understood. It was not expected to be of any concern to the Solid Rocket Booster Recovery team. Earlier in the launch flow, Endeavour's Fuel Cell #2 was replaced and the countdown picked up on September 4, 1995 at 4:30pm at the T-41.5 hour mark (Reference KSC Shuttle Status 9/01/1995) and (Reference KSC Shuttle Status 9/05/1995). The Mission Management Team (MMT) decided to scrub the August 31, 1995 scheduled launch of Endeavour on mission STS-69 due to a failure of one of three fuel cells aboard the vehicle. The scrub was called at 3:30am on 8/31/95 prior to tanking operations. Fuel cells provide electricity to the vehicle while in orbit. Mission rules state all three fuel cells must be up and operational prior to launch. At the 10:30am press conference on 8/31/95, Bob Sieck estimated the countdown would pick back up on Monday with a launch late in the week. The scrub was called due to a temperature spike in the Fuel Cell #2 exit temperature. The fuel cell is located in the right side of the payload bay. Fuel cell #2 had 1700 hours of operation and cells are typically kept in service until 2400 hours of operation. A similar fuel cell problem was previously detected on orbit during the Spacelab D-1 mission STS-61A and on the launch pad during STS-6. During STS-6, the fuel cell was replaced on the pad and similar procedures will be used for STS-69. The countdown had begun at 3pm EDT on 8/28/95. (Reference KSC Shuttle Status 8/29/1995). The previous launch date of 11:04am 8/31/95 was decided after NASA officials held a Flight Readiness Review to consider remaining issues in preparing Endeavour for the flight. Among the items reviewed and closed out was the issue of minor O-ring erosion seen in a joint of the Reusable Solid Rocket Motor (RSRM) nozzle during the last two Shuttle launches. The launch was previously placed on hold pending analysis of the solid rocket booster (SRB) nozzle o-ring seals. Possible air paths in the RTV behind the RSRM Nose Inlet Assembly to Throat Assembly joint were investigated. (Reference KSC Shuttle Status 8/23/1995). There was a rollback of Endeavour on 8/1/95 to the VAB due to Hurricane ERIN. (Reference KSC Shuttle Status 8/01/1995). Endeavour was returned to Pad 39-A on 8/08/95 with first motion occuring at 1:55am. (Reference KSC Shuttle Status 8/08/1995). Old launch date was August 5, 1995 at 10:45am with a 2 hours 30 minute launch window. Launch date was pending resolution of open items including the post flight assessment of an anomaly on one of the STS-71 solid rocket booster nozzle joints. (Reference KSC Shuttle Status 7/25/1995) Rollout to Launch pad 39-A occured on 7/5/95 with first motion out of the Vehicle Assembly Building (VAB) at around 11 p.m. The Vehicle was hard down on the pad at about 4:30am on 7/6/95. Hot fire of auxiliary power units APU units 2 and 3 occured on 7/6/95. (Reference KSC Shuttle Status 7/06/1995) Orbit: Altitude: 190 statute miles Inclination: 28.4 degrees Orbits: Duration: 10 days, 20 hours, 28 minutes, 55 seconds. Distance: 4.5 million miles Hardware: SRB: BI-074 SRM: ET : SN-72 MLP : SSME-1: SN-2035 SSME-2: SN-2109 SSME-3: SN-2029 Landing: At KSC September 18, 1995 at 7:37:56am EDT. KSC Shuttle Landing Facility Runway 33 (south-east to north-west). Sonic booms at 7:35am EDT. Banking right-hand turn of 270 degrees. Main landing gear touchdown at Mission Elapsed Time of 10days 20hr 28 56sec. Nose gear touchdown at MET 10days 20hours 29min 8 sec with Wheel Stop at 10 days 20hr 29min 52 sec or 7:38:52 EDT. Mission Highlights: STS-69 Flight Day 1 Highlights: On Thursday, September 7, 1995, 5 p.m. CDT, STS-69 MCC Status Report #01 reports: Once on orbit the crew members began to configure Endeavour for on-orbit operations. Endeavour's payload bay doors were opened about 90 minutes into the flight, followed by a 'GO' for on-orbit operations. Crew members and ground controllers in Houston recycled a circuit breaker on board Endeavour as a system on board the shuttle that automatically scrubs the air to remove carbon dioxide did not start up as expected. After cycling the breaker and reactivating the system, it is now performing perfectly. Activation of payloads also got under way with the SPARTAN-201 spacecraft systems and the Wake Shield Facility carrier in the payload bay activated. SPARTAN-201 will be deployed from Endeavour using the shuttle's robot arm Friday morning about 10:44 a.m. central time. Mission Specialists Jim Newman and Mike Gernhardt powered up Endeavour's robot arm and conducted a photographic survey on Endeavour's cargo bay. The five-member crew -- Commander Dave Walker, Pilot Ken Cockrell, and Mission Specialists Jim Voss, Newman and Gernhardt -- will begin an eight-hour sleep period at 6:09 p.m. central time. STS-69 Flight Day 2 Highlights: On Friday, September 8, 1995, 7 a.m. CDT, STS-69 MCC Status Report #02 reports: Astronauts Mike Gernhardt and Jim Newman aboard Space Shuttle Endeavour were scheduled to power up the 50-foot long Canadian-built robot arm this morning for the grapple and deployment of the SPARTAN solar science satellite by Gernhardt at 10:42 AM Central time. Endeavour will separate to a distance of about 40 nautical miles from SPARTAN, leaving the 2800 pound probe on its own for about 48 hours for observations of the phenomena of the solar corona and the solar wind. SPARTAN will be retrieved by Gernhardt through the operation of the robot arm on Sunday morning. The five astronauts on board Endeavour began their first full day in space this morning at 2:09am Central time as Mission Control awakened the crew with Elvis Presley's "You Ain't Nothing But A Hounddog", marking the start of a busy day in orbit for the so-called "Dog Crew", the nickname adopted for the STS-69 crew by Commander Dave Walker. Walker, a four-time Shuttle veteran, was awakened twice during the night by alarms on board Endeavour triggered by a temporary problem in the data path between the ship's on-board computers and the Shuttle's KU-band communications system. Walker reset the KU-system on both occassions and the entire system was rebooted by Astronaut Jim Newman after the crew was formally awakened. The KU system is currently healthy, with flight controllers reported a strong lock between Endeavour's KU-band antenna and the Tracking and Data Relay Satellite system. Engineers are trying to troubleshoot one other problem with an audio speaker in the Shuttle's middeck which apparently failed shortly after Endeavour reached orbit. It is a similar problem to one which was noted on the last flight of Endeavour in March, STS-67. The speaker problem will have no impact on any payload operations for the duration of the STS-69 mission. On Friday, September 8, 1995, 5 p.m. CDT, STS-69 MCC Status Report #03 reports: The Spartan 201 spacecraft was flying free approximately 22 miles ahead of Endeavour following its successful deployment at 10:42 a.m. central time. Mission Specialist Mike Gernhardt released the 2800 lb. free-flyer from the shuttle's robot arm and a few minutes later the Spartan spacecraft performed its characteristic 45 degree pirouette maneuver signaling the flight crew and controllers on the ground that its internal attitude control system was functioning properly. On the flight deck, Commander Dave Walker and Pilot Ken Cockrell initiated two separation burns to move Endeavour away from the Spartan solar investigation spacecraft. The NC-1 rendezvous burn set for late Friday afternoon was deleted from the crew's flight plan. That burn, which would have slowed the opening rate between the two spacecraft, would have resulted in the spacecraft being about 60 miles apart at the time of a scheduled Saturday morning engine firing. Tracking figures indicate that, even without the afternoon burn, the distance between the two spacecraft will be about 61 nautical miles by Saturday morning. Spartan will fly free of Endeavour for about 48 hours before being retrieved and reberthed in the shuttle's cargo bay for its return trip to Earth. During its free flight, the two complementary instruments on board Spartan will study the sun's corona and solar winds. Crew members also kept busy with the wide variety of payloads housed both on Endeavour's middeck and in the cargo bay. In addition, the astronauts exercised and performed routine housekeeping chores on board the orbiter. Mission Specialist Jim Newman took time from his work routine to talk with KABC Talk Radio host Michael Jackson in Los Angeles and to take phone calls from listeners. STS-69 Flight Day 3 Highlights: On Saturday, September 9, 1995, 8 a.m. CDT, STS-69 MCC Status Report #04 reports: Endeavour's astronauts pressed ahead with a variety of experiments in their third day in orbit as they prepared for tomorrow's rendezvous and retrieval of the SPARTAN solar science satellite. Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's reaction control system jets this morning to refine the Shuttle's orbit in order to maintain a distance of about 65 statute miles from the SPARTAN satellite. Another rendezvous maneuver designed to adjust Endeavour's altitude was deleted from the flight plan because of the precision with which Endeavour is flying in relation to SPARTAN. Payload controllers say SPARTAN's systems are functioning normally, although the amount of data gathered by the satellite during its 48 hours of free-flying science operations will not be known until the probe is returned to Earth. SPARTAN is scheduled to be grappled by Astronaut Mike Gernhardt through the use of Endeavour's robot arm at 9:24 AM Central time tomorrow following a series of complex rendezvous maneuvers by Walker and Cockrell to catch up to SPARTAN. The astronauts conducted work with the GLO experiment in the cargo bay, designed to measure the luminescence created around the Shuttle as it plows through atomic oxygen in low Earth orbit at a speed of five miles a second. They also monitored several experiments in the middeck area designed to capture data on materials and life science. A pair of problems continue to impact the operation of two of Endeavour's payloads. The U-V STAR experiment, which is part of the International Extreme Ultraviolet Hitchhiker payload in the cargo bay, has not worked properly since launch because of a pressure problem and a glitch in a system which enables the telescope to swivel back and forth. Another telescope in the IEH payload is working normally. The EPICS experiment in the Shuttle's middeck, designed to test the capability to separate hydrogen and oxygen components in water generated by the Shuttle, has yet to yield any results because of a suspected problem in its data acquisiton system. Troubleshooting efforts are underway for both EPICS and U-V STAR. One minor problem was resolved this morning when Astronaut Jim Voss successfully activated an audio-speaker system in the Shuttle's middeck area. Voss plugged in a different handheld microphone unit than one which was used shortly after launch and the middeck system checked out in good shape. Astronaut Gernhardt took a few minutes out this morning to discuss the progress of the flight with Scott Carpenter, one of the original Mercury 7 astronauts, who was linked to Gernhardt from an underwater research laboratory off the coast of Key Largo, Florida. Carpenter and Gernhardt discussed the interdependence of underwater research and outer space exploration. thirty years ago, Carpenter conducted a similar discussion with fellow Mercury 7 astronaut Gordon Cooper as Cooper flew in space on the Gemini 5 mission. As they passed over the Atlantic at the start of their 31st orbit, the astronauts downlinked video of Hurricane Luis swirling with maximum sustained winds of 109 miles an hour. The huge eyewall of the storm was clearly visible as Endeavour passed overhead. On Saturday, September 9, 1995, 3 p.m. CDT, STS-69 MCC Status Report #05 reports: With the Spartan spacecraft flying ahead of Endeavour, the stage is set for Sunday morning's planned rendezvous and retrieval of the free-flying science satellite. Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's reaction control system jets in a two-second burn designed to maintain a distance of at least 40 nautical miles between the two orbiting spacecraft until the rendezvous activities begin early Sunday morning. Those rendezvous activities will start with Walker and Cockrell conducting a series of complex maneuvers designed to bring Endeavour to a point about 350 feet away from Spartan by 8:59 a.m. Central on Sunday. After Walker edges Endeavour closer to Spartan, Mission Specialist Mike Gernhardt will reach out with the Shuttle's robot arm and grapple Spartan at 9:24 a.m. Central, placing it back in Endeavour's payload bay. Work with the GLO experiment mounted in the payload bay will continue overnight as the five astronauts on board sleep. The GLO instruments will measure the luminescence created around the Shuttle as it plows through atomic oxygen in low Earth orbit at a speed of five miles a second. The EPICS experiment in the Shuttle's middeck, designed to test the capability to separate hydrogen and oxygen components in water generated by the Shuttle, has been powered down after all three self-contained electrolysis units experienced an automatic shutdown. After reviewing their options for restoring power to at least two of those units, payload controllers opted to completely power off the experiment. Troubleshooting efforts continue to resolve a problem with the UV-STAR experiment which comprises a part of the International Extreme Ultraviolet Hitchiker payload. Pressure problems and difficulty commanding an elevation gimble which enables the telescope to swivel back and forth have kept the telescope from its study of the sun's coronal plasma. A second telescope is performing normally. STS-69 Flight Day 4 Highlights: On Sunday, September 10, 1995, 10 a.m. CDT, STS-69 MCC Status Report #06 reports: Endeavour's astronauts Sunday successfully grappled the SPARTAN solar science satellite following two days of data gathering independent of the Shuttle Orbiter. The grapple came about 45 minutes later than planned after the SPARTAN was in an unexpected attitude as Endeavour approached. Commander Dave Walker and pilot Ken Cockrell manually flew Endeavour around the SPARTAN to line up the satellite's grapple fixture with the orbiter's robot arm. Astronaut Mike Gernhardt captured the free-flying spacecraft at 10:02 a.m. CDT, concluding SPARTAN's study of the solar corona and the solar wind. With SPARTAN safely berthed in the cargo bay, the astronauts turn their attention to the major payload of the mission, the Wake Shield Facility. Walker and Cockrell will conduct two firings of the Ship's Orbital Maneuvering System Engines to raise Endeavour's orbit about 15 nautical miles in preparation for the Wake Shield operations. Astronaut Jim Newman plans to use the robot arm later today to grapple the 2-ton Wake Shield, but will not unberth the saucer-shaped satellite from its carrier platform until Monday morning. The Wake Shield is scheduled to be deployed by Newman tomorrow at about 4:40 AM Central time to begin 50 hours of thin film growth in an engineering demonstration for possible use in the future in improving the quality of components for semiconductors and high-tech electrical instruments. The astronauts were awakened just after Midnight Central time today to the sound of "Bingo Was His Name", another tune involving a canine theme for the self-proclaimed "Dog Crew", sung by Madeline Cockrell, the 5-year old daughter of Endeavour's Pilot. On Sunday, September 10, 1995, 3:30 p.m. CDT, STS-69 MCC Status Report #07 reports: With the Spartan spacecraft back in Endeavour's payload bay, the shuttle's robot arm has a firm grip on the Wake Shield Facility, ready to send it on its free flight away from Endeavour early Monday morning. Earlier this afternoon, Commander Dave Walker and Pilot Ken Cockrell twice fired Endeavour's orbital maneuvering system engines bringing Endeavour to a 215 nautical mile circular orbit required to support Wake Shield deploy activities. With that complete, Mission Specialist Jim Newman took control of Endeavour's robot arm and grappled the 12 foot diameter satellite. Wake Shield will remain in that configuration overnight, latched in its cross-bay carrier and attached to the robot arm. The crew's attention turned to Wake Shield operations following the successful retrieval of the Spartan spacecraft at 10:02 a.m. Central today. Retrieval of Spartan occurred 38 minutes late when it was found to be in an attitude, or position, other than what was expected when Endeavour made its rendezvous approach. Walker and Cockrell manually flew Endeavour in a 180 degree maneuver around Spartan, aligning the shuttle's robot arm with the grapple fixture mounted on the spacecraft. Mike Gernhardt then reached out with the arm and grabbed Spartan, tucking it into Endeavour's payload bay at 10:21 a.m. Central. Preliminary indications are that Spartan put itself in a "safe" mode, shutting down its power systems which kept it from achieving its anticipated rendezvous attitude. The exact cause of the safing will be determined once Spartan is returned to Earth, however, payload controllers believe Spartan successfully completed its mission gathering data on the sun's corona and solar winds and the shutdown likely was caused by low battery readings on board. Shortly after 3 p.m., Gernhardt began an 8-hour sleep period, to be followed an hour later by his crewmates, who will have an abbreviated 7-hour sleep period. For the next few days, Gernhardt and Newman will vary their sleep schedules so that one or both of them is awake during all critical commanding to the Wake Shield Facility. STS-69 Flight Day 5 Highlights: On Monday, September 11, 1995, 7 a.m. CDT, STS-69 MCC Status Report #08 reports: Endeavour's astronauts successfully deployed the 2-ton Wake Shield Facility satellite this morning to begin its 50-hour free flight from the Shuttle for the growth of thin films for semiconductor and electrical component use. Astronaut Jim Newman used the ship's robot arm to release the experimental satellite at 6:25 AM CDT over Western Africa at an altitude of almost 250 miles above the Earth. Within seconds of the deploy, the Wake Shield fired a small cold gas nitrogen thruster to maneuver away from Endeavour for the start of the chemical growth of the thin films. It was the first time a deployed satellite had maneuvered itself away from the Shuttle, rather than the other way around. Wake Shield's deployment had been delayed for almost two hours to enable flight controllers to troubleshoot a series of communications dropouts between the satellite and the Wake Shield's carrier platform in the Shuttle's cargo bay which acts as a radio relay system for data, telemetry and television signals. Wake Shield hung at the end of the robot arm during its night-long systems checkout. Before its deployment, the satellite was positioned over the port side of the payload bay to allow a stream of atomic oxygen in low Earth orbit to "cleanse" the side of the satellite which will fly in the direction of travel around the Earth. The satellite will create a wake behind it during its freeflight in which scientists believe a nearly perfect vacuum will be created for the pristine growth of thin film wafers to be used in semiconductors and other hight-tech electrical components. The last major step prior to the deployment was the checkout of the Wake Shield's attitude control system, which developed a problem during the STS-60 mission in February 1994, preventing the satellite from being set free. This time, the so-called Attitude Determination and Control System checked out in good shape, clearing the way for Wake Shield's release. The Wake Shield is scheduled to be retrieved by Newman through the use of the robot arm on Wednesday, but not before the satellite is used as a target for a series of jet thruster plume tests by Commander Dave Walker and Pilot Ken Cockrell to collect data on the effect of jet firings on a free-flying satellite. Endeavour is currently orbiting the Earth at an altitude of 250 statute miles, completing an orbit of the Earth every 90 minutes. All of Endeavour's systems are functioning in excellent shape. On Monday, September 11, 1995, 5 p.m. CDT, STS-69 MCC Status Report #09 reports: Trailing Endeavour by just over 14 nautical miles, the 2-ton Wake Shield Facility began its first thin film processing run at 3:33 p.m. Central today. Payload controllers successfully commanded the Wake Shield through a series of activities to prepare its surface for the epitaxial film growth process, handing command duties over to Mission Specialist Jim Newman when Endeavour moved out of range of the Tracking and Data Relay Satellite System. With Wake Shield's sample materials and substrate surfaces prepared, the first of seven planned thin film growth runs began. The first run is expected to last about three hours and be a "dirty" run, removing any residual contamination present in the containers housing the sample growth materials. Earlier this afternoon, Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's reaction control system jets in a burn that slowed the rate at which the two spacecraft are separating. By the time of a scheduled rendezvous burn at 4:36 a.m. Tuesday, the Wake Shield will be approximately 30 nautical miles behind Endeavour. The Wake Shield is scheduled to be retrieved on Wednesday following more than 48 hours of thin film growth activities, but will spend the final five hours of its free-flight serving as a target as Commander Dave Walker and Pilot Ken Cockrell aim Endeavour's jet thrusters toward Wake Shield, to determine the effects of the jet firings on a free-flying satellite. On board, the five astronauts are asleep. Mission Specialist Mike Gernhardt will wake up at 9:09 p.m. following a 7-hour sleep period. His four crew mates began an 8-hour sleep period at 4:09 p.m. and will awaken at 12:09 a.m. Tuesday. Endeavour is currently orbiting the Earth at an altitude of 250 statute miles, completing an orbit of the Earth every 90 minutes. All of Endeavour's systems are functioning in excellent shape. STS-69 Flight Day 6 Highlights: On Tuesday, September 12, 1995, 8:30 a.m. CDT, STS-69 MCC Status Report #10 reports: The manufacture of thin film compounds for improved semiconductor and electrical component use proceeded on schedule overnight aboard the free-flying Wake Shield Facility as Endeavour's astronauts monitored the process from their orbiting spaceship. However, about 7 a.m. CDT the 4300-pound, saucer-shaped satellite put itself in a safe mode after three successful growths of thin films. Scientists plan to complete seven growths before the satellite's scheduled retrieval Wednesday morning. Just before the fourth growth began, the Wake Shield pitched forward slightly after sensing a temperature increase. Wake Shield's systems were shut down and science activities temporarily halted to allow temperatures on the satellite to cool. Payload controllers are assessing the situation and its impact on the satellite's continued operations. The Wake Shield is trailing Endeavour by about 40 miles, just where officials hoped it would be to avoid any possible contamination from the Shuttle's jet thrusters. Wake Shield must maintain as clean an environment as possible as it orbits the Earth to enhance the quality of the thin film compounds. Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's reaction control system jets to stop the opening rate between the Shuttle and the Wake Shield in preparation for tomorrow's rendezvous and retrieval of the satellite. The Wake Shield is scheduled to be grappled by robot arm operator Jim Newman 9/13/95 at about 10:15 AM Central time. Walker took a few minutes out of his schedule to discuss the progress of the STS-69 mission with reporters from television stations in Atlanta and Boston. Later this morning, Walker planned to conduct a ship-to-ship conversation with STS-73 Commander Ken Bowersox, who along with his six crewmates, climbed aboard Columbia on Launch Pad 39-B at the Kennedy Space Center for the final hours of a dress rehearsal of the countdown which will lead to their launch in just over two weeks on a 16-day Spacelab microgravity research mission. On Tuesday, September 12, 1995, 6 p.m. CDT, STS-69 MCC Status Report #11 reports: The manufacture of semiconductor thin film compounds aboard the Wake Shield Facility satellite, released from Endeavour on Monday, is planned to resume later tonight following about a 12-hour rest to allow the satellite's attitude control system to cool from previous operations. Due to the delay and subsequent plans to allow future such cooling periods, shuttle managers this afternoon decided to extend the time Wake Shield will spend flying free of Endeavour by about 24 hours. The extra time will mean the satellite will not be retrieved until Thursday. Previously, it would have been recaptured on Wednesday. The additional 24 hours of free-flying time will be gained by scheduling the crew activities that had been planned to occur the day after Wake Shield was retrieved to now take place during the extra day the satellite spends away from the shuttle. The overall duration for Endeavour's mission has not been changed and landing remains scheduled for September 18. Controllers for the Wake Shield Facility believe the extra operations time will allow them to complete almost all of the thin film growths that had been originally planned. The satellite may be taken out of the "safe" mode that it has been in for cooling purposes and resume operations as early as 10 p.m. CDT today. Prior to the heating problems experienced with the attitude control system, three of the planned total of seven film manufacturing runs had already been completed. For the remainder of operations, cooling periods that could last as long as eight to ten hours will take place in between film manufacturing runs. Due to the slower-than-anticipated thin film operations, some secondary experimental objectives of the satellite, such as operations with the Charging Hazards and Wake Studies and the Shuttle Plume Impingement Experiment, may be reduced from what was originally planned. Operations with all of the secondary experiments are still expected, however, although in a limited fashion. With the change in plans for Endeavour's retrieval of the satellite, activities for the crew when they awaken will include some off-duty time, operations with the secondary payloads aboard Endeavour, and checkouts of the spacesuits that will be used by astronauts Mike Gernhardt and Jim Voss during a spacewalk on Saturday. The crew is currently in the midst of an eight-hour sleep period and will awaken for day seven of the mission at 10:39 p.m. CDT today. The Wake Shield Facility is trailing about 39 miles behind Endeavour and closing in on the shuttle at less than one mile with each hour and a half long orbit of Earth. STS-69 Flight Day 7 Highlights: On Wednesday, September 13, 1995, 7 a.m. CDT, STS-69 MCC Status Report #12 reports: The resumption of the growth of thin films aboard the free-flying Wake Shield Facility was delayed again today by the inability of payload controllers to trigger the flow of arsenic from source cells on the Wake Shield onto a substrate platform on the experiment side of the disc-shaped satellite. Wake Shield project engineers continue to troubleshoot the problem in the hope of growing up to four additional films for enhanced semiconductor production. Given a bonus day in orbit after having science operations suspended yesterday by an attitude control system problem, Wake Shield's molecular beam epitaxy instruments were turned on just before 3 AM CDT, some 20 hours after the satellite was placed in a so- called "safe mode" because of a temperature increase in the spacecraft's attitude control system and a slight pitch in its orientation. The science instruments on the Wake Shield were once again shut down after the arsenic flow problem developed to enable them to cool off in the hope of making additional attempts to grow thin films. Plans had called for two thin films to be grown during the day today before the instruments would be shut down and cooled off for a 10-hour period. Commander Dave Walker and Pilot Ken Cockrell fired Endeavour's maneuvering jets early this morning for 15 seconds to slightly narrow the distance between the Shuttle and the Wake Shield. Endeavour will stay about 25 miles ahead of Wake Shield throughout the day, setting the stage for its rendezvous and retrieval of the 4300-pound disc-shaped satellite tomorrow about 9:39 AM Central time. While Wake Shield operations were restored, Payload Commander Jim Voss and Mission Specialist Mike Gernhardt conducted a thorough checkout of the spacesuits they will don Saturday for the second Shuttle spacewalk of the year. The spacewalk is designed to test thermal improvements to the bulky spacesuits as well as the tools and techniques which may one day be used in the assembly of the International Space Station. The astronauts were awakened late Tuesday night for their seventh day in space to the theme song from the movie, "Patton", a tribute to Voss, who was promoted to the rank of Colonel-select in the U.S. Army. Endeavour and the Wake Shield Facility are orbiting the Earth every 92 minutes at an altitude of about 250 miles with all of their systems operating normally. On Wednesday, September 13, 1995, 3 p.m. CDT, STS-69 MCC Status Report #13 reports: After resolving some initial difficulties with the flow of arsenic from a source cell, the Wake Shield Facility resumed its thin film growth activities. During the film growth, the shutter on an aluminum source cell apparently failed to close on command, but payload controllers report that will not affect the quality of the film sample. A second epitaxial film growth will be conducted overnight as the crew sleeps, following a minimum 6-hour cool-down period of the Wake Shield instruments. Tonight's run should last about three hours and will be followed by a final 6-hour instrument cool down in anticipation of Thursday morning's rendezvous and retrieval of the 4,300 pound satellite. The five astronauts on board Endeavour -- Commander Dave Walker, Pilot Ken Cockrell and Mission Specialists Jim Voss, Jim Newman and Mike Gernhardt -- enjoyed a few hours of off-duty time today, following several busy days on orbit that saw them deploy two spacecraft and retrieve one. Wake Shield will be retrieved at 9:39 a.m. CDT Thursday when Walker maneuvers Endeavour into position allowing Jim Newman to use the shuttle's robot arm to pluck Wake Shield from orbit. Endeavour will begin its approach toward Wake Shield about 6:30 a.m. Central and for about 2 1/2 hours Walker and Cockrell will maneuver Endeavour into position and fire its jet thrusters at pre-determined distances to measure the effects of the firings on the free- flying Wake Shield. STS-69 Flight Day 8 Highlights: On Thursday, September 14, 1995, 7 a.m. CDT, STS-69 MCC Status Report #14 reports: Endeavour's astronauts closed in on the Wake Shield Facility this morning for a retrieval of the space manufacturing satellite following three days of free-flying production of semiconductor material. Commander Dave Walker and Pilot Ken Cockrell maneuvered Endeavour to a point just 400 feet in front of the 4300-pound satellite, where a series of jet thruster firings were planned to gather data on the effect of thruster plumes against orbiting space structures. Flight controllers were expected to make a real-time decision on whether or not to proceed with the jet thruster tests based on an evaluation of the Wake Shield's attitude control system, which has held the stainless steel spacecraft in a steady orbit since its deployment from Endeavour on Monday. Astronaut Jim Newman is expected to grapple Wake Shield with the Shuttle's robot arm between 8:09 AM and 8:30 AMCentral time to complete the Wake Shield's three-day freeflight. During that time, four thin films of semiconductor material were grown in a carousel on the back side, or wake side of the satellite. An attempt to grow a fifth and final thin film was called off late Wednesday when Wake Shield officials detected a low reading in one of four batteries providing power to the satellite. Following its retrieval, the Wake Shield will be berthed onto its carrier platform in Endeavour's cargo bay. Tomorrow, Newman will unberth the satellite once again and maneuver it over the Shuttle's bay for additional experiments spanning several hours to gather information on the electrically charged environment around the Orbiter as it plows through atomic oxygen in low Earth orbit at a speed of five miles a second. The astronauts were awakened late last night at 11:09 PM Central time to the theme song of the cartoon show, "Underdog", in tribute to Astronaut Mike Gernhardt, who carries the same nickname. On Thursday, September 14, 1995, 3 p.m. CDT, STS-69 MCC Status Report #15 reports: With the Wake Shield Facility stowed securely in Endeavour's payload bay, the five astronauts on board are enjoying a well-deserved rest. After Commander Dave Walker and Pilot Ken Cockrell manuevered Endeavour alongside the 4300-pound satellite, Mission Specialist Jim Newman reached out with the shuttle's robot arm and plucked it from orbit. Capture came at 8:59 a.m. CDT, with berthing of Wake Shield back in its carrier platform at 10:18 a.m. Prior to capturing Wake Shield, Walker and Cockrell performed a series of 14 thruster firings at distances of 290 and 200 feet respectively. These jet firings were designed to gather data on the effect of thruster plumes against orbiting space structures. The Wake Shield's attitude control system performed well during the thruster firings as sensors measured the force and pressure of the jet plumes. During Wake Shield's three days of free flight, four of seven possible epitaxial film runs were successfully completed. The films will be evaluated once the satellite is returned to Earth. With its two free-flying payloads retrieved and secured in the payload bay, Endeavour's astronauts turned their attention to the remaining four days of activity. Walker and Cockrell fired Endeavour's orbital maneuvering system jets this afternoon to lower Endeavour's orbit from 216 nautical miles to 183 nautical miles. At the same time, Mission Specialists Jim Voss, Jim Newman and Mike Gernhardt began preparing Endeavour for Saturday morning's planned spacewalk, lowering the cabin pressure to 10.2 psi from the standard 14.7 psi. Voss and Gernhardt will conduct a 6-hour spacewalk to evaluate thermal modifications to their spacesuits and test tool handling techniques for possible space station assembly. Shortly before beginning an 8-hour sleep period at 3:09 p.m., Walker reported to ground controllers that the handles of the rowing machine used during exercise were stuck in the extended position. While engineers on the ground are reviewing repair options, a bicycle ergometer is available on board for the crew to use. The crew will be awakened by Mission Control at 11:09 p.m. to begin another day on orbit. Endeavour is orbiting the Earth every 92 minutes at an altitude of 183 nautical miles with all of its systems operating normally. STS-69 Flight Day 9 Highlights: On Friday, September 15, 1995, 7 a.m. CDT, STS-69 MCC Status Report #16 reports: Endeavour's astronauts completed work with the Wake Shield Facility today by lifting the satellite out of its platform in the Shuttle's cargo bay one more time to gather data about electrically charged particles which stream over a spacecraft in low Earth orbit. The Wake Shield was unberthed about 2 Central time and was hung over the side of Endeavour's cargo bay at the end of the ship's robot arm by Astronaut Jim Newman for CHAWS, the Charging Hazards and Wake Studies Experiment. It is an Air Force sponsored experiment designed to collect data on the buildup of electrical fields around an orbiting space vehicle. Engineers intend to use the information to better understand how the ionized particles interfere with spacecraft communications and the operation of orbiting spacecraft. The Wake Shield remained fixed to the end of the Shuttle's mechanical arm for about 5 hours for CHAWS data-gathering, before Newman maneuvered the satellite back down onto its berthing platform where it was latched it in place to wrap up the Wake Shield's scientific investigations. Payload Commander Jim Voss and Mike Gernhardt also reviewed their timeline once again for tomorrow's six-hour spacewalk in Endeavour's cargo bay to test new thermal improvements made to their spacesuits and some of the tools and techniques which may be used to assemble the International Space Station. Voss and Gernhardt are scheduled to float out into the cargo bay to begin their six-hour extravehicular activity at about 3 Central time Saturday. The crew was awakened late Thursday night for their ninth day of work in space to the tune "He's A Tramp", taken from the cartoon movie, "Lady and the Tramp". On Friday, September 15, 1995, 4 p.m. CDT, STS-69 MCC Status Report #17 reports: Shortly after waking up, Jim Voss and Mike Gernhardt will begin preparing for their spacewalk which will test new thermal improvements made to their spacesuits and some of the tools and techniques which may be used to assemble the International Space Station. Pilot Ken Cockrell will assist Voss and Gernhardt as they climb into their spacesuits and prepare for the second spacewalk of the year. During the spacewalk, Mission Specialist Jim Newman will hoist Voss and Gernhardt outside the warmth of Endeavour's payload bay using the shuttle's robot arm to maneuver them into a colder attitude to validate thermal modifications made to the suits' liquid cooling garments and gloves. Voss and Gernhardt are scheduled to float out into the cargo bay to begin their six-hour extravehicular activity at about 3 a.m. Central time Saturday. The Wake Shield Facility is once again back in Endeavour's payload bay following five hours of investigations into how ionized particles in the plasma field around a spacecraft may interfere with communications and operations. Wake Shield was supporting CHAWS, the Charging Hazards and Wake Studies Experiment, an Air Force-sponsored experiment. The crew also spent time discussing Endeavour's mission and activities with media during an inflight press conference this afternoon. On Saturday, September 16, 1995, 5:30 a.m. CDT, STS-69 MCC Status Report #18 reports: Astronauts Jim Voss and Mike Gernhardt floated out into Endeavour's cargo bay early this morning for a 6 1/2 hour spacewalk designed to test new thermal improvements made to their spacesuits and the tools and techniques which may be used one day in the assembly of the International Space Station. The spacewalk began at 3:20 a.m. Central, after Voss and Gernhardt breathed pure oxygen in Endeavour's airlock to cleanse the nitrogen from their bloodstreams in a standard pre-spacewalk procedure. The first task for the spacewalkers was to install thermal sensors on Endeavour's robot arm and at a work site mounted on the starboard wall of the Shuttle's payload bay. The sensors measure temperature levels in the cargo bay to provide data on how hot and cold the spacewalkers can get as they perform their work. Voss and Gernhardt removed a debris shield from the work site, manipulated a duplicate of a computer control box for a robot arm under development for the Space Station and tested new helmet lights and suit heaters as they maneuvered around the cargo bay with relative ease. The spacewalk is scheduled to conclude at about 10 a.m. when the two astronauts climb back into Endeavour's airlock. The remaining three astronauts, Dave Walker, Ken Cockrell and Jim Newman have been assisting with the spacewalk from the flight deck of the orbiter with Newman serving as the primary choreographer with Voss and Gernhardt. Newman performed a spacewalk on a Shuttle flight two years ago to evaluate tools and techniques for future spacewalks. On Saturday, September 16, 1995, 2:30 p.m. CDT, STS-69 MCC Status Report #19 reports: With a 6-hour 46-minute spacewalk under their belts, Endeavour's astronauts completed the final major milestone of the flight. Jim Voss and Mike Gernhardt began the spacewalk at 3:20 a.m. Central today, evaluating thermal improvements made to their spacesuits and a variety of tools and techniques which may be used in the assembly of the International Space Station. In turn, Gernhardt and Voss each spent 45 minutes on the end of Endeavour's mechanical arm as Jim Newman maneuvered them away from the radiated warmth of the payload bay. With the Shuttle's payload bay pointed away from the Sun, the spacewalkers were exposed to temperatures as low as minus 120 degrees Fahrenheit during this "cold soak" evaluation. Voss and Gernhardt continually provided subjective ratings on their comfort levels to flight controllers on the ground. Temperature measurement devices mounted on the robot arm and in the payload bay will provide objective data that will be correlated with their evaluations. Throughout the entire spacewalk activity, both Voss and Gernhardt reported they were very comfortable, both during their cold soak evaluation and as they worked through a series of repetitive tool-handling tasks in Endeavour's payload bay. With all their objectives complete and after stowing their tools and equipment, the two spacewalkers made their way back into the airlock, closed the hatch and began to repressurize the airlock. With the pressure at about 10.2 psi, Ken Cockrell opened the hatch to Endeavour's middeck and welcomed his crewmates back on board. Endeavour's crew cabin was then repressurized back to 14.7 psi while Voss and Gernhardt were helped out of their spacesuits. Following an 8-hour sleep period, Endeavour's astronauts will be awakened at 10:09 p.m. to begin their final full day on orbit. Early Sunday morning, Commander Dave Walker, Cockrell and Newman will check out Endeavour's flight control surfaces and conduct a hot fire test of the reaction control system jets in anticipation of Monday morning's return trip to Earth. STS-69 Flight Day 10 Highlights: On Sunday, September 17, 1995, 7 a.m. CDT, STS-69 MCC Status Report #20 reports: Endeavour's astronauts tested their ship's systems and packed up the Orbiter for their trip home tomorrow to complete the fifth Shuttle mission of the year. With all of the mission's objectives completed, Commander Dave Walker and Pilot Ken Cockrell fired up one of Endeavour's hydraulic power units and conducted a thorough checkout of the Shuttle's flight control systems to insure that the Orbiter is in top shape for tomorrow's high-speed return to Earth. Walker and Cockrell also tested the Shuttle's reaction control system jets as part of the standard pre-landing inspection of key Shuttle components. With that out of the way, the astronauts reviewed their entry and landing checklists and began to pack up their gear aboard Endeavour, deactivating secondary experiments and stowing the cabin for landing. The preliminary weather forecast for landing calls for acceptable weather for Endeavour's homecoming at the prime landing site at the Kennedy Space Center. The backup landing site at California's Edwards Air Force Base will not be called up for support. There are two landing opportunities available tomorrow in Florida, the first calling for a deorbit burn at 6:35 AM Eastern time, leading to a landing at 7:38 AM Eastern time. Early in the morning, astronauts Jim Voss and Mike Gernhardt, who successfully conducted a lengthy spacewalk on 9/16/95, turned to repair chores, freeing up a blocked waste water dump line through a plan developed by flight controllers in Mission Control. The in-flight maintenance procedure cleared the way for a dump of accumulated waste water aboard Endeavour. On Sunday, September 17, 1995, 1 p.m. CDT, STS-69 MCC Status Report #21 reports: Endeavour and its five astronauts are ready for their return trip to Earth, concluding a voyage of about 4.5 million miles. The crew spent much of its day packing up equipment and checklists used during 10 days of on-orbit activity. The astronauts also transferred some of the accumulated waste water onboard Endeavour into a contingency water container when attempts to free up a blocked waste water dump line were unsuccessful. The five member crew -- Commander Dave Walker, Pilot Ken Cockrell and Mission Specialists Jim Voss, Jim Newman and Mike Gernhardt -- will receive a wake-up call from Mission Control at 10:09 p.m. Central to begin final preparations for Endeavour's reentry and landing at the Kennedy Space Center. Shortly after 1:30 a.m. Central the crew will begin its deorbit preparations and at 2:49 a.m., Endeavour's payload bay doors will be closed. There are two landing opportunities available tomorrow, both to the Kennedy Space Center. The first opportunity calls for a deorbit burn at 5:35 a.m., with a landing on Runway 33 at 6:38 a.m. Central. The second landing opportunity comes one orbit later, with Endeavour's orbital maneuvering system jets being fired for the deorbit burn at 7:12 a.m., resulting in a landing at 8:15 a.m. Central. The preliminary weather forecast for Monday's landing calls for acceptable weather at the Kennedy Space Center in Florida with scattered clouds, light winds from the northwest and only a slight chance of early-morning ground fog. The backup landing site at California's Edwards Air Force Base will not be called up to support tomorrow's landing. Endeavour continues to circle the Earth every 91 minutes at an altitude of 214 statute miles. STS-69 Flight Day 11 Highlights: On Monday, September 18, 1995, 9 a.m. CDT, STS-69 MCC Status Report #22 reports: Commander Dave Walker and Pilot Ken Cockrell guided Endeavour to a smooth touchdown at the Kennedy Space Center at 6:38 a.m. Central time today to wrap up an 11-day mission that saw crew members successfully deploy and retrieve two satellites and conduct a 6-hour 46-minute spacewalk. After firing Endeavour's braking rockets at 5:35 a.m., Walker and Cockrell brought Endeavour home to Runway 33 at the Kennedy Space Center's Shuttle Landing Facility to complete its 4.5 million mile mission. Main gear touchdown occurred at 6:38 a.m., with nose gear touchdown nine seconds later and wheel stop at 6:38:55 a.m. The STS-69 mission duration was 10 days 20 hours 28 minutes and 55 seconds. The STS-69 crew members are expected to return to Ellington Field about 10 hours after landing. Mission Name: STS-73 (72) Columbia (18) Pad 39-B (34) 72nd Shuttle Mission 18th Flight OV-102 NOTE: Click Here for Countdown Homepage Crew: Kenneth D. Bowersox (3), Commander Kent V. Rominger (1), Pilot Kathryn C. Thornton (4), Payload Commander Catherine G. Coleman Ph.D (1), Mission Specialist Michael E. Lopez-Alegria (1), Mission Specialist Fred W. Leslie Ph.D (1), Payload Specialist Albert Sacco Jr Ph.D (1), Payload Specialist David H. Matthiesen (0) Ph.D, Alternate Payload Specialist R. Glynn Holt (0) Ph.D, Alternate Payload Specialist Milestones: OPF -- 4/14/95 VAB -- 8/21/95 PAD -- 8/28/95 TCDT -- 9/11/95 FRR -- 9/14/95 (Reference KSC Payload Status Sep 1995) (Reference KSC Shuttle Status Sep 1995) (Reference KSC Shuttle Status Oct 1995) Payload: USML-2/EDO, OARE-06, 3DMA, STABLE Mission Objectives: The second United States Microgravity Laboratory (USML-2) Spacelab mission will be the prime payload on STS-73. The 16-day flight will continue a cooperative effort of the U.S. government, universities and industry to push back the frontiers of science and technology in "microgravity", the near-weightless environment of space. Some of the experiments being carried on the USML-2 payload were suggested by the results of the first USML mission that flew aboard Columbia in 1992 during STS-50. The USML-1 mission provided new insights into theoretical models of fluid physics, the role of gravity in combustion and flame spreading, and how gravity affects the formation of semiconductor crystals. Data collected from several protein crystals grown on USML-1 have enabled scientists to determine the molecular structures of those proteins. USML-2 builds on that foundation. Technical knowledge gained has been incorporated into the mission plan to enhance procedures and operations. Where possible, experiment teams have refined their hardware to increase scientific understanding of basic physical processes on Earth and in space, as well as to prepare for more advanced operations aboard the international Space Station and other future space programs. USML-2 experiments include the Surface Tension Driven Convection Experiment (STDCE), the Drop Physics Module, the Drop Dynamics Experiment; the Science and Technology of Surface-Controlled Phenomena experiment; the Geophysical Fluid Flow Cell Experiment; the Crystal Growth Furnace, the Orbital Processing of High Quality Cadmium Zinc Telluride Compound Semiconductors experiment; the Study of Dopant Segregation Behavior During the Crystal Growth of Gallium Arsenide (GaAs) in Microgravity experiment; the Crystal Growth of Selected II-VI Semiconducting Alloys by Directional Solidification experiment; the Vapor Transport Crystal Growth of Mercury Cadmium Tellurida in Microgravity experiment; the Zeolite Crystal Growth Furnace (ZCG), the Interface Configuration Experiment (ICE), the Oscillatory Thermocapillary Flow Experiment; the Fiber Supported Droplet Combustion Experiment; the Particle Dispersion Experiment; the Single-Locker Protein Crystal Growth experiment; (including the Protein Crystallization Apparatus for Microgravity (PCAM) and the Diffusion-controlled Crystallization Apparatus for Microgravity (DCAM)). the Crystal Growth by Liquid-Liquid Diffusion, the Commercial Protein Crystal Growth experiment; the Advanced Protein Crystallization Facility, Crystallization of Apocrystacyanin C experiment; Crystal Structure Analysis of the Bacteriophage Lamda Lysozyme, Crystallization of RNA Molecules Under Microgravity Conditions experiment; Crystallization of the Protein Grb2 and Triclinic Lysozyme experiment; Microgravity Crystallization of Thermophilic Aspartyl-tRNA Synthetase and Thaumatin experiment; Crystallization in a Microgravity Environment of CcdB experiment; A Multivariate Analysis of X-ray Diffraction Data Obtained from Glutathione S Transferase experiment; Protein Crystal Growth: Light-driven Charge Translocation Through Bacteriorhodopsin experiment; Crystallization of Ribosome experiment; Crystallization of Sulfolobus Solfataricus Alcohol Dehydrogenase experiment; Crystallization of Turnip Yellow Mosaic Virus, Tomato Aspermy Virus, Satellite Panicum Mosaic Virus, Canavalin, Beef Liver Catalase, Concanavalin B experiment; Crystallization of the Epidermal Growth Factor (EGF); Structure of the Membrane-Embedded Protein Complex Photosystem I; Crystallization of Visual Pigment Rhodopsin; Commercial Generic Bioprocessing Apparatus; Astroculture Facility and Experiment. Spacelab Glovebox Facility experiments include the Zeolite Crystal Growth Glovebox, Protein Crystal Growth Glovebox and the Colloidal Disorder-Order Transitions, USML-2 flight controllers and experiment scientists will direct science activities from NASA's Spacelab Mission Operations Control facility at the Marshall Space Flight Center. In addition, science teams at several NASA centers and universities will monitor and support operations of a number of experiments. Other payloads on board include the Orbital Acceleration Research Experiment (OARE), Space Acceleration Measurement System (SAMS), Three Dimensional Microgravity Accelerometer (3DMA), Suppression of Transient Accelerations By Levitation Evaluation (STABLE) and the High-Packed Digital Television Technical Demonstration system. Launch: Friday, October 20, 1995 at 9:53:00 a.m. EDT. Launch window was 2 hours 30 min. The countdown clock picked up at 7:30pm at the T-11 hour mark with a scheduled T-0 at 9:50 a.m. Loading of fuel was completed at 3:53am. The crew suited up at 6:00am and traveled out to Launch Pad LC-39B. (Reference KSC Shuttle Status 10/18/1995). At the post-launch press conference, Jim Harrington, Director of Shuttle Operations mentioned the launch countdown went relatively smoothly. At the beginning of the count there was a problem with one of 3 redundant sensors on Liquid Oxygen (LOX) portion of the External Tank toggling from wet to dry. The sensor was bypassed. After tanking, one of the relief valves in the LOX storage area had a slow leak internally that will be fixed during ground operations. There was also a fire alarm that went off accidently at the 155ft level during the later part of the count while the close out crew was still on the pad. No fire was detected. Also, a right hand mid joint heater trimmed down and the launch team switched over to the backup system. Finally, the range command destruct system lost communications between the ROCC and the antenna. A contingency plan was work and the count was picked back up. The launch scheduled for October 15 10:46 a.m EDT was scrubbed at 1:25pm EDT due to weather conditions at KSC that were unacceptabledue for launch. Due to the scheduled launch of the Atlas launch vehicle on Tuesday morning (10/17/95), the next available time frame in which Columbia could have been launched was Thursday, Oct. 19 at 9:49 a.m. EDT. Bad weather delayed the Atlas launch which slipped the launch of Columbia till Friday. The launch window extended until 12:19 p.m. that day. (Reference KSC Shuttle Status 10/16/1995). Fueling operations had started around 1:20 a.m. EDT with the loading of 1/2 million gallons of liquid hydrogen and liquid oxygen into the External Tank and were completed at 4:03am. Since the available launch period extended to 1:35 p.m. EDT based on the Transoceanic Abort Landing (TAL) lighting conditions at Ben Guerir, Morocco the crew was boarded one hour later than planned to provide a increased opportunity for favorable weather towards the end of the launch window. They departed the Operations and Checkout Building (O&C) at 7:20am EDT. On 10/14/95, the Mission Management Team closed the two open issues with flight hardware which caused a one day postponement of the launch of Columbia on Mission STS-73. The issue with a duct on the main engines was resolved by technicians taking ultrasonic measurements of the duct to verify adequate wall thickness. That work along with additional data analysis have allowed engine managers to conclude that there are 3 good SSMEs on Columbia. The issue with a General Purpose Computer (GPC) was resolved by removing and replacing the suspect unit. The new GPC installed in Columbia has been tested and approved for flight support. (Reference KSC Shuttle Status 10/14/1995). On 10/13/95, NASA managers postponed the launch of Space Shuttle Columbia on Mission STS-73 to 10/15/95 in order to work an issue with the Space Shuttle Main Engine (SSME) and another with the orbiter's onboard computer (GPC). The issue with the Shuttle main engines involves inspection work that is required because of a crack found in a high pressure oxidizer duct on a main engine (SSME SN# 2015) being tested at the Stennis Space Center in Bay St. Louis, Mississippi on 10/11/95. Inspection of the failed duct indicates the crack happened in a weld area and was due to the duct wall being too thin. The work on Columbia involves ultrasonic inspection of the welds on each engine's high pressure oxidizer duct to ensure proper wall thickness. There are seven different welds on each engine duct. A separate issue was worked by the launch team with one of Columbia's General Purpose Computers (GPC). During prelaunch testing, the ground crew noticed an unusual response in the data transmission between the GPC and associated electronics hardware. The launch scheduled for Saturday, 10/7/95 at 9:41am EDT was scrubbed at 10:05am EDT ( T-minus 20 minute mark ) by KSC Launch Director Jim Harrington and the Mission Management Team due to a problem with one of Columbia's two Master Events Controllers (MEC). The MECs control all critical functions that occur on the Shuttle at T-0 and through flight, including routing commands from the Shuttle s onboard computers to fire the explosive bolts that hold the solid rocket boosters to the Mobile Launch Platform (MLP) and the pyrotechnics that separate the boosters from the external tank during flight. (Reference KSC Shuttle Status 10/07/1995). The countdown had started and proceeded with little difficulty. During tanking operations, the only minor problem was an overvoltage failure of a ground pump (Primary Pump 126). Tanking was picked up using the backup pump 127 and the count proceeded normally. The flight crew had departed the Operations and Checkout Building for Pad 39-B at 6:25am EDT and was onboard Columbia. At 8:56am (T-minus 29 minute mark), the launch team called a Launch Commit Criteria violation due to a failed self test on B-Core (Port 1, bit 5) of Columbia's Master Events Controller #1. The four cores are all redundant allowing the Shuttle quad-redundancy. Launch commit criteria rules require all four cores to be operating properly for safe flight. The launch countdown was placed on hold at the T-minus 20 minute mark while commands were issued to determine if the problem was with the controller or with instrumentation. It was determined the problem was with the controller which will need to be replaced. At this time, the external tank will be drained and purged, the Rotating Service Structure (RSS) moved back around the vehicle and preparations made to gain access to the aft engine compartment to remove and replace the MEC. The MEC is scheduled to be removed on Monday 10/9/95 and the replacement MEC tested on Tuesday 10/10/95. Some of the experiments in the USML-2 spacelab module must be serviced before another launch attempt can be made and the onboard cryogenic tanks must be off-loaded and then re-loaded with liquid hydrogen and liquid oxygen reactants. The launch on 10/6/95 was scrubbed at 3:33am for a minimum of 24 hours due to a problem in the orbiters #1 hydraulic system which services Columbia's nose wheel steering system. On 10/6/95, during pre-launch checkout, engineers noticed a problem with the volume of hydraulic fluid in the system. They will cycle the hydraulic system's fill and dump valve and run a compressibility test. (Reference KSC Shuttle Status 10/06/1995). The launch scheduled for 10/5/95 was posponed 24 hours due to bad weather from Hurricane Opal. (Reference KSC Shuttle Status 10/05/1995) The launch attempt of Columbia on September 28, 1995 at 9:35 a.m was scrubbed due to indications of a hydrogen leak in Space Shuttle Main Engine (SSME) #1 (SN#-2037) . The scrub was called at 4 a.m. on 9/28/95. The hydrogen main fuel valve needed to be replaced which delayed the launch approximately one week. (Reference KSC Shuttle Status 9/28/1995). During the launch postponement press conference, Jim Harrington, KSC Launch Director and John Plowden, Rocketdyne Site Director reported that Tanking operations had begun approximately an hour later than planned primarily due to lightning in the area of the launch pad. Liquid hydrogen was in recirculation for about 30 minutes and the main fuel valve had begun to chill down. When it reached the temperature of -10F degrees the valve started to leak. Tanking operations were stopped when the temperature on the valve reached the Launch Commit Criteria cuttoff limit of -250F degrees at the downstream side of the valve. Normal temperature on the valve runs at -100F to -150F degrees. This would have been the first launch of SSME engine SN#-2037 and the failed valve but it had been thru 7 static firings during ground tests. The engine and valve were last tested at cryogenic temperatures during hot firing June 15, 1995 at Stennis Space Center in Mississippi. A failure of this nature has occured only once before during the STS-2 tanking test. That failure was due to metallic contamination in the downstream seal of the valve. The valve is accessable via the AFT engine compartment. It weighs about 75 pounds with a flow path of 2.5 inches. It will be replaced at the pad. The bad valve will be sent back to the Rocketdyne factory in California for testing. The launch countdown had begun at 4am on Monday, September 25, 1995 and the crew arrived at the KSC Shuttle Landing Facility (SLF) at 8:20 a.m. (Reference KSC Shuttle Status 9/25/1995). RTV backfilling for both solid rocket boosters of Space Shuttle Columbia was performed on 9/5/95. (Reference KSC Shuttle Status 9/05/1995). Earlier, on 8/8/95, engineering analysis indicated that the No. 2 main engine on Columbia was unacceptable for flight and was removed and replaced with an engine originally slated to fly on mission STS-74. (Reference KSC Shuttle Status 8/08/1995). The replacement engine does not have a block one liquid oxygen pump. (Reference KSC Shuttle Status 8/15/1995). Orbit: Altitude: 150 nm (172 statute miles) Inclination: 39.0 degrees Orbits: 255 Duration: 15 days, 21 hours, 53 minutes, 16 seconds. Distance: 6.6 million miles Hardware: SRB: BI-075 SRM: ET : SN-73 MLP : SSME-1: SN-2037 SSME-2: SN-2031 SSME-3: SN-2038 Landing: November 5, 1995 at 6:45:21am EST at KSC Runway 33. Main gear touchdown at 6:45:21 EST (MET 15days 21hr 52min 21sec). Nose gear touchdown at 6:45:35 EST (MET 15days 21hr 52min 35sec). Wheels stop at 6:46:16 EST (MET 15days 21hr 53min 16sec). Two landing opportunities were possible for a landing on 11/5/95.. Columbia took the first opportunity which began with a deorbit engine firing by Columbia at 5:46 a.m. EST, on the mission's 255th orbit, leading to a touchdown at the Kennedy Space Center at 6:45 a.m. EST. The second opportunity would have begun with a deorbit burn at 7:20 a.m. EST on orbit 256 leading to a 8:19 a.m. EST touchdown. Mission duration was 17hours short of the existing shuttle record set by Endeavour. Mission Highlights: The seven-member crew will work in two 12-hour shifts, for 16 days conducting 14 major experiments and a variety of other medical and engineering investigations. The experiments are part of the planned operations of the United States Microgravity Laboratory 2 payload. STS-73 Flight Day 1 Highlights: On Friday, October 20, 1995, 12 p.m. CDT, STS-73 MCC Status Report #01 reports: The Space Shuttle Columbia blasted off from its Florida launch pad at 8:53 a.m. CDT today after a heavy cloud cover that earlier had shrouded the area cleared. Today's launch tied the record for launch attempts set by STS 61C which launched on its seventh try in January of 1986. Once on orbit, the crew members set to work configuring Columbia for on-orbit operations. Columbia's payload bay doors were opened about 90 minutes into the flight, followed by a "go" for on-orbit operations. With all systems aboard Columbia performing well, the orbiter continues to circle the Earth every 92 minutes at an altitude of 150 nautical miles or 172 statute miles. On Friday, October 20, 1995, 5 p.m. CDT, STS-73 MCC Status Report #02 reports The astronauts set up the Spacelab module mid-day Friday and began work which will cover 14 major research activities and a number of other medical and engineering studies. Columbia is in a 172-statute mile high orbit with all systems functioning well. Handover from the Red Team to the Blue Team of astronauts is scheduled for approximately 7:30 p.m. Friday. The Red Team picks up work again Saturday morning at about 6:30 a.m. CDT after their wakeup call. On Friday, October 20, 1995 at 11 p.m. CDT, STS-73 Payload Status Report #01 reports: This 16-day mission will build on the foundation of its predecessor, USML-1, which flew in 1992. USML-2 will continue microgravity investigations in fluid physics, materials science, biotechnology, combustion science and commercial space processing technology. These experiments support work that historically yields long-range benefits to the quality of life, and will play a vital role in work on the International Space Station. Mission Scientist Marcus Vlasse observed, "The results from these experiments will provide important input into our future technology needs." More than 400 hours of the crew's time will be dedicated to the USML-2 experiments. The seven-member crew onboard Columbia will work dual 12-hour shifts which allows the experiment operations to continue around the clock in the "shirt-sleeve" microgravity environment of the Spacelab module. Microgravity is approximately one millionth the gravity experienced on Earth, made possible in low Earth orbit by a condition known as freefall. Freefall provides the microgravity environment for the occupants and experiments onboard as the Shuttle falls around the Earth in such a way that it stays the same height above ground. About two hours after launch, red team Payload Commander Kathy Thornton and Payload Specialist Al Sacco went to work activating the Spacelab, while the blue team members slept in preparation for their shift. Thornton began processing experiment samples in the Commercial Generic Bioprocessing Apparatus, a tool which allows a variety of sophisticated biological experiments to be performed in one piece of hardware. Its 132 test-tube size chambers allow multiple commercial customers to take advantage of the microgravity environment. Major areas of investigation include biomedical testing and drug development, ecological test systems, and biomaterials products and processes. Thornton mixes the samples by turning a plunger or activator on the facility. After mixing, some of the samples will then be placed in an incubator at a prescribed temperature, while others will be placed in a rack at room temperature. Thornton also activated and began check-out of the Crystal Growth Furnace, a facility to further understand and find better ways of processing semiconductor crystals which are used for products such as computer chips and infrared detectors. In microgravity, melting and resolidifying the specialized semiconductor materials or growing crystals by vapor diffusion (heating the substance to a vapor and then cooling it, causing material to deposit in thin layers), the elements are distributed more evenly. This makes a purer metal and a better end product. Crew members activated one of two protein crystal growth facilities on this flight: the European Space Agency's Advanced Protein Crystallization Facility. Because a protein's structure determines its function, scientists are aiming to grow the largest, most perfect crystals possible. That way they can more easily see how a particular protein functions in the human body. Later in the day, the crew lowered the Shuttle's cabin temperature after it caused a slight rise in the temperature of a Commercial Protein Crystal Growth experiment thermoelectric cooler. Ideal temperature in the coolers is four degrees Celsius. Investigators anticipate the situation will be resolved soon as the Shuttle naturally cools to its normal post-launch temperature. There has been no impact on crystal growth. Pa yload Specialist Sacco activated two instruments which will determine what effect crew movements, equipment operations and Shuttle maneuvers can have on sensitive USML-2 experiments. The Space Acceleration Measurement System collects data for post-mission evaluation, while the Three Dimensional Microgravity Accelerometer collects acceleration data for both post mission and real time data analysis. Armed with data collected by these instruments, scientists can make changes to their experiments to compensate for on- orbit disturbances, thus utilizing their microgravity time to the fullest. Sacco powered on the High-Packed Digital Television Technical Demonstration, a new digital television system which will be tested on this flight. This experiment could allow researchers on the ground at the Marshall Space Flight Center in Huntsville, Ala., and at numerous remote research sites around the country, to choose from up to six channels of experiment video being transmitted simultaneously from orbit. During the next 12 hours, blue team Mission Specialist Catherine Coleman and Payload Specialist Fred Leslie will continue activating experiments in the Spacelab, including the Surface Tension Driven Convection experiment and the Astroculture plant growth facility. STS-73 Flight Day 2 Highlights: On Saturday, October 21, 1995, 7 a.m. CDT, STS-73 MCC Status Report #03 reports: Columbia's crew continued research work in the United States Microgravity Lab-2 during the night uninterrupted by any problems with the spacecraft. The Blue Team crew members -- Mission Specialists Mike Lopez-Alegria and Cady Coleman and Payload Specialist Fred Leslie -- wrapped up their first, full 12-hour shift in the lab at about 6:38 a.m. CDT. During the last part of the Blue shift, new shuttle equipment being carried aboard Columbia for the first time this mission that allows television to be sent from the ground to the crew was tested. The ground-to- air television test, which included live scenes from Mission Control, appeared good onboard the shuttle, reported Columbia Pilot Kent Rominger. The Red Team crew -- Commander Ken Bowersox, Rominger, Payload Commander Kathy Thornton and Payload Specialist Al Sacco -- awoke from their first night in orbit at about 3:53 a.m. CDT today and relieved the Blue Team in the lab module this morning. The Red Team will remain on duty until 6:53 p.m. CDT. Highlights of NASA Television today will include the Flight Day 2 Mission Update program airing at 11:30 a.m. CDT; a Mission Status Briefing press conference at 1 p.m.; and an interview of the Red Team by the Florida Radio Network at 5:58 p.m. CDT that may include phone-in questions from listeners On Saturday, October 21, 1995, 2 p.m. CDT, STS-73 MCC Status Report #04 reports: All systems aboard the Space Shuttle Columbia continue to work well as the orbiter's seven member crew continues its microgravity work in the United States Microgravity Lab-2 (USML-2). The Red Team crew -- Commander Ken Bowersox, Pilot Kent Rominger, Payload Commander Kathy Thornton and Payload Specialist Al Sacco -- spent today in the lab module working on a variety of experiments and tasks. The Red Team hands over its duties to the Blue Team at 6:53 p.m. today. The Blue Team crew - Mission specialists Mike Lopez-Alegria and Cady Coleman, and Payload Specialist Fred Leslie -- then will take a turn in the lab. The Blue Team's shift ends at 6:38 a.m. Sunday. The first in-flight special event is scheduled for 5:58 p.m. CDT today when available crew members talk to Alan McBride of the Florida Radio Network. The event will be audio only. On Saturday, October 21, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #02 reports: (0/21:07 MET) The second United States Microgravity Laboratory's "blue team" -- Mission Specialists Mike Lopez-Alegria and Cady Coleman, and Payload Specialist Fred Leslie -- spent a busy first shift putting more of the mission's microgravity experiments into operation. Alegria activated the Protein Crystallization Apparatus for Microgravity experiments located in two Shuttle middeck lockers. During USML-2, the experiments will grow more than 800 protein crystals -- six times the number normally accommodated in the same space. Principal Investigator Dr. Dan Carter of NASA's Marshall Space Flight Center who has flown the apparatus on several Shuttle missions has grown protein crystals with enhanced internal order. Because a protein's structure determines its function, researchers analyze the improved crystals to understand the structure in greater detail. For instance, a number of pharmaceutical companies have samples in USML-2 protein crystal growth facilities. Improved crystals will aid their design of new drugs. The superior crystals grown in space contribute insights that otherwise might not have been possible, despite huge investments in ground-based research. Another USML-2 protein facility, the University of Alabama at Birmingham's Commercial Protein Crystal Growth vapor diffusion apparatus, had experienced somewhat elevated temperatures yesterday due to warmer than normal crew cabin temperatures after launch. After the cabin cooled, the temperature in the refrigerated incubator was down to about 40 degrees Fahrenheit (4.5 degrees Celsius), well within satisfactory limits. Coleman spent the first portion of her shift activating more of the biological samples in NASA's Commercial Generic Bioprocessing Apparatus. The facility, managed by Bioserve Space Technologies at the University of Colorado in Boulder, is a generic research tool for a wide variety of life-science experiments. Subjects range from molecules and cells to tiny organisms. Groups of eight syringe-like fluid containers are packaged together so they can be activated simultaneously by turning a crank on the pack. Leslie's first major assignment was loading six samples into the Marshall Center's Crystal Growth Furnace, a multi-user facility for growing crystals of semiconducting material, metals and alloys. Crew members also installed a flexible glovebox atop the furnace, which they will use later in the mission to remove crystallized samples and replace them with new sample cylinders. An automatic sample exchanger within the furnace allows ground controllers to command processing of multiple crystals in sequence, freeing the Spacelab crew for other duties. Just after midnight, Crystal Growth Furnace team members began vapor crystal growth of their first semiconductor sample, a mercury cadmium telluride compound provided by Dr. Heribert Wiedemeier of the Rensselaer Polytechnic Institute in Troy, New York. Wiedemeier is examining the initial phase of vapor crystal growth in a complex alloy semiconductor. The vapor transport method deposits layers, or thin films, of mercury cadmium telluride on a cadmium telluride substrate, or base. The material is used in infrared detectors for products such as cancer detection devices and the military's night-vision goggles. Wiedemeier's analysis of the mercury cadmium telluride crystal he grew during USML-1 revealed new information about how microgravity affects formation of the initial layer on the substrate. His USML-2 experiment zeros in on that stage of growth, which determines the atomic arrangement of the entire crystal and thus the ultimate quality of the material. Later, Coleman checked out power, lighting, ventilation and video in the versatile Glovebox facility, provided by the European Space Agency. The transparent enclosure, which also flew on USML-1, is a self-contained work area for experiment handling and observation that protects against possible contamination of the Spacelab environment. USML-2 crew members will use the Glovebox for seven investigations, several of which will enhance other mission experiments. The Spacelab crew then turned their attention to the Lewis Research Center's Surface Tension Driven Convection Experiment, another facility returning after a USML-1 debut. The apparatus allows investigators to view in great detail the basic fluid mechanics and heat transfer of thermocapillary flows, motions created within fluids by non- uniform heating of their free surfaces. Though masked by gravity in ground-based processing, such flows during melting and resolidifying can create defects in high-tech crystals, metals, alloys and ceramics. Leslie installed the facility's infrared imager, video cassette recorder, and the first test module. Coleman then checked out the video system, which allows ground controllers to see how changes in heating and surface shape affect flows within the fluid. During the upcoming shift, Payload Specialist Al Sacco will work with his Glovebox Zeolite Crystal Growth experiment, and Payload Commander Kathy Thornton will start up the Drop Physics Module. Initial operations for the Geophysical Fluid Flow Cell Experiment are scheduled for later this afternoon. STS-73 Flight Day 3 Highlights: On Sunday, October 22, 1995, 7:30 a.m. CDT, STS-73 MCC Status Report #05 reports: Columbia sailed through a second smooth night in orbit, continuing around-the- clock research in its cargo bay laboratory. The spacecraft remains in excellent condition, and the focus in Mission Control has been on assisting with the experiment operations when needed. The Red Team crew -- Commander Ken Bowersox, Pilot Kent Rominger, Payload Commander Kathy Thornton and Payload Specialist Al Sacco -- is now on duty in the United States Microgravity Lab-2, having started a 12-hour shift at 6:38 a.m. CDT. The Blue Team -- Mission specialists Mike Lopez-Alegria and Cady Coleman, and Payload Specialist Fred Leslie -- will begin an eight-hour sleep period at 8:53 a.m. Highlights on NASA Television today include the Flight Day 3 Mission Update program airing at 11:30 a.m.; the Mission Status Briefing at 1 p.m.; and a replay of video highlights from the past 24 hours of STS-73 airing on the Flight Day Video File at 3:30 p.m. Other activities upcoming today include a second test of a system that allows television to be transmitted to the shuttle from Mission Control to be conducted at about 5:03 p.m. The ground-to-air shuttle television equipment is flying aboard Columbia for the first time on STS-73 as a test objective of the mission. On Sunday, October 22, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #03 reports: (1/21:07 MET) The seven-member crew of the second United States Microgravity Laboratory had a busy 24 hours during their second day in space. Experiments continue to operate smoothly and on schedule. Fluids physics Payload Specialist Fred Leslie spent his shift overnight conducting initial experiment runs in the Surface Tension Driven Convection Experiment. The investigation examines subtle fluid motions, called thermocapillary flows, created by variations in temperature on a fluid's surface. Though overshadowed by gravity-driven flows on Earth, thermocapillary flows during melting and resolidifying can create defects in high-tech crystals, metals, alloys and ceramics. The goal of USML-2 surface tension experiments is to measure the transition from steady, two-dimensional flows to oscillatory, or three-dimensional, flows within silicone oil. Leslie reported the onset of oscillations early in the first experiment run, as ground controllers watched three different views of the experiment chamber transmitted simultaneously by Hi-Pac TV. While data from the July 1992 flight confirmed the model for steady thermocapillary flows proposed by the science team from Case Western Reserve University in Cleveland, Ohio, it also indicated that smaller chambers and less viscous fluid would be needed to study the transition from steady to oscillatory flow. These improvements were made, and a new optical system was added so investigators can observe how changes in surface shapes influence the beginning of oscillations. After crew members activated the Geophysical Fluid Flow Cell experiment, the University of Colorado science team took over operation from the ground. The investigation models flows in oceans and atmospheres of planets and stars using silicone oil between two rotating hemispheres -- one of stainless steel inside another of transparent sapphire. Controllers can vary electrical charges which simulate gravity, fluid temperature and rotation speed of the spheres in order to reflect conditions in the different environments. The geophysical cell's first experiment run mimicked the sun's plasma flows, repeating its primary study during Spacelab 3 in 1985. "This allows us to compare USML-2 results with our previous experiment," said Principal Investigator Dr. John Hart. "The instrument seems to be working great." Solar physics researchers at the University of Colorado will use data from this experiment to build better computer models of fluid behavior on the sun. Glovebox Protein Crystal Growth experiments occupied Mission Specialist Cady Coleman for the majority of last night's shift. Coleman used a variety of procedures to manually mix protein and activator solutions in the Glovebox enclosure. Crew members will observe crystallization of the samples as the mission progresses and adjust upcoming Glovebox protein activations accordingly. Shuttle protein experiments over the past decade have frequently produced more perfect crystals than those grown on Earth, and investigators are constantly refining methods to improve that quality. Modifications made during the USML-1 Glovebox experiment resulted in several crystals of much higher quality than had ever been grown before. Earlier in the day, Payload Commander Kathy Thornton made videotapes of proteins growing in Principal Investigator Dr. Alex McPherson's handheld diffusion test cells. In liquid- liquid diffusion, fluids are not mixed but diffuse into each other by random motion of molecules. This method is difficult on Earth because gravity causes solutions with different densities to mix. Also, the denser crystals settle to inappropriate parts of the cell. Thornton used sound waves to control positions of marked Styrofoam and plastic balls inside the Jet Propulsion Laboratory's Drop Physics Module. In addition to giving her practice operating the equipment, Thornton's success assured investigators that free-floating liquid drops can be manipulated as desired during upcoming experiment operations. Improved understanding of fluid physics would produce advances in industries from chemical engineering to pharmaceuticals. Payload Specialist Al Sacco is principal investigator for two USML-2 investigations into the growth of zeolite crystals, widely used as catalysts and filters in the chemical processing industry. Video downlink Saturday from the Shuttle showed Sacco's hands in the Glovebox facility as he mixed 16 samples of alumina and silica solutions to initiate growth in the Zeolite Crystal Growth Glovebox experiment. Sacco then used the most effective mixing procedures to prepare other samples for heating in the Zeolite Crystal Growth Furnace. The Astroculture facility team was elated to see video downlink of their potato plants on day two of the mission. Ten small tubers are being grown in the chamber to test how microgravity affects starch accumulation in plants. This information will play an important role in future long- duration space missions such as the International Space Station, where plants could provide food, water and oxygen for crews, as well as removing carbon dioxide from the space habitat. On Saturday, the Crystal Growth Furnace completed its first sample, a semiconductor crystal grown by the vapor transport technique. A six-hour growth period deposited a thin mercury cadmium telluride crystal onto a cadmium telluride substrate, or base. The infrared-detecting semiconductor crystal will be analyzed to determine whether defects from the base material were translated to the atomic structure of the crystal grown in microgravity. Furnace team members then began melting a semiconductor sample aimed at eliminating defects in a substrate material. The alloying element zinc is added to this cadmium telluride substrate to minimize strain where the two crystals join. Processing of the semiconductor compound, from the Northrop- Grumman Corp. in Bethpage, New York, will continue for more than 90 hours. On Sunday, October 22, 1995, 12 p.m. CDT, STS-73 MCC Status Report #06 reports: Space Shuttle Columbia continues to perform well in its supporting role for the U.S. Microgravity Lab-2. Since Friday morning's launch, the orbiter has remained a steady host, providing electrical power, cooling and other needs to keep the orbiting laboratory in business. The seven-member crew continues to work around the clock in two shifts. Columbia is in a 170x167 statute mile orbit, circling the Earth every 90 minutes. STS-73 Flight Day 4 Highlights: On Monday, October 23, 1995, 9:30 a.m. CDT, STS-73 MCC Status Report #07 reports: The Red Team crew -- Commander Ken Bowersox, Pilot Kent Rominger, Payload Commander Kathy Thornton and Payload Specialist Al Sacco -- began a 12-hour shift at 6:38 a.m. CDT. Their Blue Team crewmates began eight hours of sleep at 8:53 a.m. CDT. Bowersox and Rominger took part in the third test thus of a new shuttle system that allows the transmission of television from Mission Control to Columbia. The crew discussed the progress of the flight with Capcom Tom Jones and Flight Director Rob Kelso in Mission Control. Bowersox reported that he has been impressed by Columbia's performance so far and complemented workers at the Kennedy Space Center that prepared the shuttle for flight. The test was the first to involve two-way television -- simultaneous transmissions to and from Columbia -- and was highly successful. On Monday, October 23, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #04 reports: (2/21:07 MET) Research in microgravity continues around the clock as crew members of the second United States Microgravity Laboratory (USML- 2) onboard the Shuttle Columbia work in dual 12-hour shifts. The red and blue Spacelab teams devoted the majority of the time on their last shifts to the Drop Physics Module, the Surface Tension Driven Convection Experiment and Glovebox Protein Crystal Growth operations. Drop Physics Module Project Scientist Arvid Croonquist and his science team watched downlink video of the first liquid drop deployment in their facility during an initial test run on Sunday. Payload Commander Kathy Thornton deployed the 3/4-inch (4 cubic centimeter) drop of water, then released it, using precisely controlled sound waves to manipulate the drop's movements. Thornton reported that the drop's performance was close to expectations, its rotation visible by following the movement of tiny plastic particles suspended in the water drops as reference points. Thornton spent a good portion of her shift deploying and manipulating different-sized drops in the facility. Mission Specialist Cady Coleman also devoted several hours last night to familiarizing herself with the operation of the Drop Physics Module. These preliminary runs give crew members valuable practice injecting, controlling and retrieving liquid drops in the unique environment of weightlessness. The runs also allow ground controllers to fine-tune procedures in preparation for upcoming science investigations. Insights gained into basic fluid physics and the properties of liquid surfaces will benefit a variety of industries, from pharmacology to industrial chemistry. Payload Specialist Al Sacco and Coleman finished the mission's initial round of protein crystal growth activations in the Glovebox facility. The experiment, provided by the Center for Macromolecular Crystallography in Birmingham, Ala., will help improve protein crystal growth procedures for future Shuttle missions and on the International Space Station. Among the proteins Sacco activated was feline calcivirus, similar to a virus that causes digestive problems in humans. He also set up initial conditions for growth of a collagen binding domain protein, important in the study of arthritis and joint disease. One of the proteins Coleman activated last night was duck delta crystallin. Derived from the eye of a duck, it is much like a protein that causes a rare but deadly inherited disease in humans. Thornton and Payload Specialist Fred Leslie continued tests in the Surface Tension Driven Convection Experiment, an investigation which could eventually lead to better, stronger high-tech crystals, metals, alloys and ceramics by modeling the transition from steady thermocapillary fluid flows to oscillatory (or varying) flows. Unsteady flows in materials processing such as crystal growth could reduce the quality of the final product. "Once we understand when and how oscillations occur, we should eventually be able to design processes to control them," said Co- Investigator Dr. Yasuhiro Kamotani of Case Western Reserve University. In this series of convection tests, crew members drew down the volume of silicone oil in the experiment chamber to create a concave surface. As a laser gradually heated the surface, team members were able to identify the transition point where oscillations began to occur in each run. "We've never seen this kind of transition before, because we have no way to create a large curved liquid surface on the ground," said Lewis Research Center Project Scientist Alex Pline. Crew members initiated another Lewis Research Center investigation, the Colloidal Disorder-Order Transition experiment. This Glovebox study researches what happens at the boundaries between solid and liquid states during crystallization of a colloid. Colloids are suspensions of finely divided solids or liquids in gaseous or liquid fields. For instance, paint, ink and milk are colloids found in everyday life. Investigators will use results to model the complex interactions of atoms -- the basic building blocks for everything in the universe. Thornton worked Sunday with the Geophysical Fluid Flow Cell Experiment, which models fluid flows on Earth, planets and stars. Thornton set up different scenarios, adjusting fluid temperature, speed of sphere rotation, and electrical charges (which simulate gravity) to mimic various environments. Investigators hope to one day use information gleaned from experiments such as this to aid in forecasting ocean flows and weather patterns. The science team is currently working a problem relaying scenario temperature parameters to the experiment hardware, but Principal Investigator Dr. John Hart says they are getting good data. The cadmium zinc telluride crystal is just over a third of the way through its growth in the Crystal Growth Furnace. The predecessor experiment on USML-1 yielded a crystal of the infrared-detecting semiconductor a thousand times more perfect than any cultivated on Earth. Principal Investigator Dr. David Larson hopes to demonstrate that equivalent quality can be reproduced with the USML-2 crystal. The Astroculture team has noticed new growth on the 10 small potato tubers in their facility onboard Columbia. The potatoes will be analyzed post-mission to determine how microgravity affected starch accumulation. In addition, this flight of Astroculture is the last in a series to evaluate each of the critical subsystems needed for the construction of a reliable plant growth unit. After it is flight qualified, the unit will be available for sale or lease to commercial enterprises. Plants may provide food, water and oxygen for crews on long-duration space flights. Science activities scheduled for the next 12 hours include more Drop Physics Module and Surface Tension Driven Convection Experiment activities. On Monday, October 23, 1995, 6:30 p.m. CDT, STS-73 MCC Status Report #08 reports: Circling the Earth at over 17,000 miles an hour and at an altitude of approximately 170 statute miles, Columbia is flying in the gravity gradient attitude, tail to Earth in its most stable and vibration-free condition to facilitate the delicate microgravity experiments being conducted. The astronaut crew, divided into Red and Blue teams, works shifts for around-the-clock science in 14 major areas of experimentation. STS-73 Flight Day 5 Highlights: On Tuesday, October 24, 1995, 8 a.m. CDT, STS-73 MCC Status Report #09 reports: Columbia's crew worked through the night in the shuttle's cargo bay research lab with no significant spacecraft problems encountered. Flight controllers in Mission Control have virtually no issues of concern with Columbia's systems, which continue to operate nearly perfectly. The Red team began a 12-hour shift at 6:38 a.m. CDT, relieving the Blue team crew members who had worked through the night. During the night, there was a short loss of communications with Columbia. The shuttle was out of touch with the ground for a few minutes longer than planned following a normal loss of communication that occurs each orbit as it moves out of range of the NASA communications satellites. The extended loss of signal was due to a ground problem with the communications network and did not interrupt any lab or spacecraft operations nor pose any problem for the crew. The ground problem was quickly corrected and Columbia's communication systems were confirmed to be in excellent condition with no functional problems. On Tuesday, October 24, 1995 at 6 a.m. CDT, STS-73 Payload Status Report #06 reports: (3/21:07 MET) Experiments aboard the Shuttle Columbia continue to operate extremely well as the second United States Microgravity Laboratory enters its fifth day in space. Fluid physics studies, unhampered by the distortions caused by gravity, again took center stage. As he had for the previous two nights, Payload Specialist Fred Leslie devoted most of his shift to the Lewis Research Center's Surface Tension Driven Convection Experiment. The study seeks a precise understanding of flows created by temperature differences across a liquid's surface, called thermocapillary flows. In particular, the USML-2 experiment should determine the conditions under which thermocapillary flows begin to oscillate, or become irregular. While thermocapillary flows are almost impossible to study on the ground because of the overpowering influence of gravity, they can affect processing of molten materials on Earth such as formation of semiconductor crystals or precision welding. Leslie used a larger experiment chamber than he had on previous surface tension experiment runs -- 3/4-inch (2 cm) diameter as opposed to 1/2-inch (1.2 cm) -- and heated the silicone oil surface with a laser. The surface was flat for the first three runs and curved for the fourth. Principal Investigator Dr. Simon Ostrach believes that the onset of oscillations is affected by a number of factors, including heat source, temperature distribution on the fluid surface, surface shape and container size. USML-2 experiments are using multiple combinations of conditions to build a through understanding of oscillatory thermocapillary flow in microgravity. The Geophysical Fluid Flow Cell Experiment team controlled their investigation remotely from Marshall's Spacelab control center, with input from colleagues at the University of Colorado in Boulder. Payload Specialist Leslie, a co- investigator for the experiment, calls it "a planet in a test tube." Silicone oil between two rotating hemispheres can be manipulated to simulate fluid flows in the atmospheres of giant gas planets, the sun or the Earth. Last night's experiment simulated atmospheric dynamics of the sun . When ground-based experiments use spheres as planetary models, gravity exerts force in a single direction. Therefore, a uniform gravitational force cannot be exerted on all the sphere's surfaces. In space, simulated gravities can be varied as necessary. This experiment should give theorists insights for interpreting and predicting problems in complex fluid systems, including Earth's atmosphere, oceans, core and mantle. Mission Specialist Cady Coleman is conducting the mission's first run of the Glovebox Interface Configuration Experiment for Principal Investigator Dr. Paul Concus of the Lawrence Berkeley Laboratory in California. The study examines how movements of fluids in microgravity, such as fuel in spacecraft tanks, are influenced by the shapes of their containers. On Earth, gravity causes fuel and other liquids to drain from containers in predictable ways. When planning space-based operations, it is important to be able to predict the locations and configurations that fluids will assume in containers under low-gravity conditions. Thus far, mathematical models exist for only a few container shapes. Coleman used a wedge-shaped vessel for this run, adjusting the wedge angle to see how different angles affect fluid behavior. Earlier, Coleman spent several hours following up on Glovebox Protein Crystal Growth experiments she began on previous shifts. Experiment team members at the Center for Macromolecular Crystallography in Birmingham, Ala., sent Coleman instructions for modifying conditions as she activated a new batch of proteins. She will compare growth progress in the various samples to determine which conditions work best for specific types of proteins. Mission Specialist Mike Lopez-Alegria and Coleman also monitored other protein crystal experiments onboard. This mission carries a record number of protein samples and protein crystal growth facilities. The European Space Agency's Advanced Protein Crystallization Facility enables videotaping of three different methods of crystal growth. Marshall Space Flight Center has two protein crystal growth experiments on USML-2, which use a total of four facilities. In addition to their Glovebox experiment, the Center for Macromolecular Crystallography is growing more crystals in the often-used Vapor Diffusion Apparatus as well as by a newer batch method. Proteins are molecules which serve biological functions. Understanding the structure of these molecules gives scientists an idea what other molecules would interact with the protein and change the way it functions, for instance to help cure or treat an illness. Space-based protein crystal growth experiments have consistently produced high-quality crystals for structural analysis, as well as providing better understanding of the dynamics of protein crystal growth. Red team members will devote the majority of their upcoming shift to Drop Physics Module, Surface Tension Driven Convection Experiment and Glovebox Protein Crystal Growth operations. On Tuesday, October 24, 1995, 6 p.m. CDT, STS-73 Payload Status Report #07 reports: (4/09:07 MET) "This mission is a beautiful example of interactive science due to the collaborative efforts between the principal investigators, the cadre and the crew," observed Mission Scientist Marcus Vlasse referring to the second United States Microgravity Laboratory (USML-2) mission. USML-2 scientific investigations continue to operate smoothly and on schedule. Downlink video from the Shuttle on Hi-Pac TV this morning displayed a circular image that appeared to contain a swirling nocturnal snowstorm. This was actually an experiment run of the Surface Tension Driven Convection Experiment which studies thermocapillary flows using aluminum oxide particles suspended in silicone oil illuminated by a laser light. By relaying commands to Payload Commander Kathy Thornton to adjust the temperature parameters on the surface of the liquid, Project Scientist Alex Pline and his science team are able to study the transition from steady fluid flows to more oscillating, or unstable flows, that result when heat is applied to a liquid's surface. Thermocapillary flows are present on Earth in many industrial and materials processing methods, but are difficult to study due to the presence of gravity-driven fluid flows. By conducting this experiment in microgravity, scientists can isolate the thermocapillary flows, gaining insight on how and why they occur. The Astroculture plant growth facility continues to operate smoothly, providing the proper water, humidity and light to the small potato tubers growing within the apparatus. Co- investigator Dr. Ted Tibbitts commented on the progress of the 10 small potatoes. "They look very happy and well, staying very turgid, which means they have not wilted, so the environment is good for them," he said. Downlink video shows only green leaves, since the tubers are buried in the soil. That's the exciting part, Tibbitts said, but something their team won't see until the end of the mission. The potatoes will be studied after the mission to determine the effects microgravity has on starch accumulation in plants. Scientists believe plants will play an important role in long-duration space flights, such as missions on the International Space Station, providing food and water to crews, replenishing oxygen and also helping remove excess carbon dioxide from the air. Investigators also believe plants could provide a psychological lift to astronauts in an otherwise sterile environment. "I think it's beautiful," exclaimed Payload Specialist Al Sacco describing the 1 inch (8 cubic centimeter) drop of water he successfully deployed and released from the Drop Physics Module apparatus this morning. A crew member manipulates the liquid drops using sound waves in order to study their behavior under the influence of external forces. This type of research will help investigators understand science and technology in which liquid drops have a role, from rain formation and weather patterns to chemical processing. Later this week, an experiment known as Science and Technology of Surface-Controlled Phenomena will be conducted with a surfactant added to the water drop. Surfactants, such as soap, reduce the holding power of a liquid surface. These chemicals play an important role in industrial processes, among them the production of cosmetics, the dissolution of proteins in synthetic drug production and the enhancement of oil recovery. Data from these observations should give a better understanding of the molecular forces acting in the surface layer of simple water drops and should provide a better basis for industrial applications. Near the end of the red shift, Pilot Ken Rominger used a camcorder to film a couple of unattended experiment operations starting with the Commercial Generic Bioprocessing Apparatus. This multi-user facility allows a variety of sophisticated bioprocessing experiments to be performed in one piece of hardware. Major areas of focus on USML-2 include biomedical testing and drug development, ecological systems development and biomaterials products and processes. Next Rominger focused his camera on the Crystal Growth by Liquid-Liquid Diffusion apparatus sponsored by the Marshall Space Flight Center in Huntsville, Ala. The experiment consists of four transparent hand-held diffusion test cells, attached to the outside of a Shuttle middeck locker so they are easily seen. In this unique crystal growth facility, proteins and precipitants diffuse into one another by random action of molecules instead of being mixed. Sacco spent about 4 hours this afternoon in the Glovebox facility activating protein crystal growth samples. Later the samples were transferred to a specialized incubator maintained at a prescribed temperature. Proteins play important roles in daily life, from providing nourishment to fighting disease. Because a protein's structure determines its function, researchers seek to grow large, well-ordered crystals for post-mission structural analysis. On Tuesday, October 24, 1995, 5 p.m. CDT, STS-73 MCC Status Report #10 reports: The Red Team members will hand over science operations to their colleagues on the Blue Team at 6:38 p.m. CDT today, then resume work in the Spacelab at 6:38 a.m. CDT Wednesday. On Wednesday's schedule for televised events is an NBC News Channel interview with Mission Specialist Michael Lopez-Alegria at 5:43 a.m. CDT and a special video downlink at 7:23 a.m. CDT in anticipation of Game Five of the 1995 World Series. The crew will downlink video of STS-73 Commander Ken Bowersox throwing out the ceremonial first pitch. The video will be played on the Jacobs Field TV screen in Cleveland before Thursday's game. STS-73 Flight Day 6 Highlights: On Wednesday, October 25, 1995, 7:30 a.m. CDT, STS-73 MCC Status Report #11 reports: As the Blue Team was finishing up it's shift, Mission Specialist Mike Lopez- Alegria was interviewed by the NBC Newschannel. During the 5:23 a.m. CDT interview, Lopez-Alegria said the crew was well-adjusted to the onboard routine and "having a ball." The Blue Team completed it's shift at 6:38 a.m. CDT and the Red Team -- Commander Ken Bowersox, Pilot Kent Rominger, Payload Commander Kathy Thornton and Payload Specialist Al Sacco -- is now on duty. During the Red Team shift today, Bowersox, Thornton and Sacco will all have a half -day off. Shuttle crew members are each given a day off to relax during long- duration shuttle missions such as STS-73. Bowersox and Thornton will have time off during the first part of the shift and Sacco will have time off during the later part of today's shift. The port payload bay door on Columbia remains partially closed, about 51 degrees from fully open. However, at about 8:43 a.m. CDT, Bowersox will fully open the door. It will remain open for about one hour to allow for a dump of water from the condensate tank associated with the United States Microgravity Lab-2 module. The lab condensate tank collects water from dehumidifiers in the lab and must be dumped periodically, about each six days, during lab flights. The door is being opened during the dump to ensure there is ample clearance for the wastewater, which is ejected from a nozzle on top of the lab's forward end cone. Once the dump is completed, the door will again be closed partially to protect the radiators and cooling lines along its interior from debris impacts in orbit due to the shuttle's orientation and extended stay in space. On Wednesday, October 25, 1995, 6 a.m. CDT, STS-73 Payload Status Report #08 reports: (5/21:07 MET) Overnight activities aboard the second United States Microgravity Laboratory were a balanced mix of crew-intensive fluid physics experiments and ground-controlled investigations into both fluid behavior and crystal growth. At around 1 a.m. CDT, the Crystal Growth Furnace team finished solidifying a cadmium zinc telluride crystal for Principal Investigator Dr. David Larson of the State University of New York in Stonybrook. The furnace will be allowed to gradually cool until this afternoon. Cadmium zinc telluride is used as a substrate, or base material, for infrared detecting crystals found in products such as cancer detection devices and the militaryÕs night- vision goggles. A similar crystal grown on USML-1 was a thousand times more defect-free than any comparable crystals ever grown on the ground. Larson hopes to demonstrate that the exceptional quality can be reproduced with the USML-2 sample. "A sizable amount of effort and research money is going toward Earth-based efforts to improve substrate material," said Larson. The space-grown crystals will give researchers the opportunity to prove the widely held assumption that better substrate material would dramatically improve infrared detectors. Mission Specialist Cady Coleman operated the Surface Tension Driven Convection Experiment. Initially, she lowered the level of silicone oil within the chamber to create a deeply concave surface. Later, she added oil until the surface rounded outward -- the experiment's first run with a convex surface. The size of the laser beam on the oil surface was adjusted to see how it affected the direction and nature of fluid flows, and the temperature was gradually increased to pinpoint when the flows began to oscillate. As they varied experiment conditions, ground team members saw a number of interesting oscillation patterns never observed in Earth- bound research under the influence of gravity. These observations will help scientists better understand manufacturing processes on Earth and how to improve them -- avoiding defects caused by unwanted flows when materials are cooled from a liquid or gaseous form. With Coleman operating the surface tension experiment, Payload Specialist Fred Leslie practiced drop deployment in the Jet Propulsion Laboratory's Drop Physics Module. He then began the mission's first experiment for Principal Investigator Dr. Taylor Wang of Vanderbilt University in Nashville. A cheer went up from the science team as Leslie finally succeeded in the delicate process of inserting an air bubble inside a floating water drop. This experiment examines the fluid physics of the resulting liquid shell. It could lay the ground work for encapsulating living cells to treat hormonal disorders such as diabetes. An insulin- producing pancreatic cell could be injected into the body encased in a polymer shell, which would protect the cell from immunological attack and provide timed release of the drug. "There are actually two factors at work in liquid spherical shells: fluid physics and chemical reactions," said Wang. "With these space experiments, we are able to separate them." Ground-based studies of these complex interactions are hampered by the small size of the drops which must be used and the constant motion induced by gravity. USML-2 experiments will allow experimentation with larger, stationary drops over a longer period of time. The Geophysical Fluid Flow Cell team completed another six- hour run to simulate atmospheric conditions on the sun. They gradually stepped up the electric charge on the experiment to simulate the increase in gravitational force as the sun increases mass in later stages of its evolution. This instrument revealed several new types of convection on its first flight, Spacelab 3, in 1985. Improvements for USML-2, including real-time video data, should allow even greater insights into the often baffling fluid flows of complex stellar and planetary atmospheres. On Wednesday, October 25, 1995, 6 p.m. CDT, STS-73 Payload Status Report #09 reports: (5/09:07 MET) A short period of leisure time was built into the schedule for the red shift science crew of the second United States Microgravity Laboratory (USML-2) mission today. Payload Commander Kathryn Thornton took her break in the morning, leaving Payload Specialist Al Sacco to enjoy his time off in the afternoon. Sacco spent the first part of his shift working in the Glovebox facility on protein crystal growth experiments. Various proteins from laboratories around the world are being grown in this facility. Activating one of these protein crystal growth experiments involves mixing a selected protein solution with another solution, which activates growth. The crystals are then placed in an incubator facility at a precise temperature. Sacco today initiated new protein crystal growth experiments, based on his observations of previous sets of investigations. He adjusted experiment parameters in order to modify protein crystal growth conditions such as mixing procedures, crystal seeding, crystal mounting and crystal preservation. Sacco brought on line the last of the 14 major experiment facilities during his morning shift. Marshall Space Flight Center's Suppression of Transient Accelerations by Levitation Evaluation (STABLE) is a test designed to isolate a small science experiment from high-frequency accelerations, including Shuttle operations and crew activity. The device uses a suspended platform controlled by electromagnetic actuators. Accelerometers on the platform provide data on Shuttle disturbances' data which allows position sensors to locate the platform with respect to the base, keeping the platform centered between disturbances. This greatly reduces accelerations and gives the experiment a smoother ride. An experiment known as CHUCK will debut on STABLE later in the mission. Sacco continued work today in the Geophysical Fluid Flow Cell Experiment facility. The experiment uses a stainless steel hemisphere about the size of a baseball, surrounded by a sapphire hemisphere, with silicone oil between the two. By applying an electric charge to the hemispheres, a crew member creates artificial gravity. Other parameters changed with each run are the temperature of the silicone oil and the speed of the hemispheres' rotation. In this way, a variety of fluid flows in oceans, planets and stars are mimicked, possibly helping forecast ocean flows and weather patterns. According to Principal Investigator Dr. John Hart, "We've already discovered several interesting things, and we've been able to modify our experiment operations and investigate things we wouldn't have been able to do otherwise." Pilot Ken Rominger and Sacco kept a close check on growing zeolites in the Zeolite Crystal Growth furnace today. Zeolites are inorganic compounds of aluminum, silicon and oxygen whose porous structures make them valuable catalysts and purifiers for the chemical processing industry. "We want to learn more about how zeolites nucleate and grow, and more about their structure, so we can apply that knowledge to different processes on Earth," said Co-principal Investigator Dr. Nurcan Bac of the Worcester Polytechnic Institute. "For instance, one of the zeolites in this experiment is widely used by the petroleum refining industry to crack heavy oils into gasoline. If we can increase the efficiency of this type of zeolite, we could get more refined petroleum products from the same amount of crude oil." Near the end of his shift, Sacco conducted a purge of the argon gas in the Crystal Growth Furnace. Sacco vented the gas then pumped fresh argon into the experiment chamber. This prepared the furnace for the third crystal to be grown in the facility on USML-2: a sample of gallium arsenide, a semiconductor material. Gallium arsenide crystals are valuable for use in electronic devices and a variety of other products. Provided by the Case Western Reserve University, the experiment principal investigator is Professor David Matthiesen, also an alternate payload specialist for USML-2. This crystal of gallium arsenide will enable scientists to refine techniques for more uniformly distributing a dopant, or impurity, during growth. Impurities are added to these semiconductor compounds to improve or precisely control their electronic characteristics. To produce high quality gallium arsenide crystals, scientists need to understand the process by which these impurities are distributed within the compound during crystal growth. Sacco set up the Surface Tension Driven Convection Experiment, getting it ready for Thornton to begin experiment runs after her break. While Thornton conducted constant temperature baseline tests on the fluid's curved surface, creating a variety of kaleidoscope-like patterns in the oil, video was downlinked to investigators on the ground. They periodically relayed commands to Thornton to increase or decrease temperatures across the surface of the fluid, allowing investigators to study the transition from stable fluid flows to the more unstable ones that result when the temperature is increased. One key factor prompting this research is that unwanted fluid flows can create defects in the production of high-tech crystals, metals, alloys and ceramics. Thus investigators are seeking to understand how and why they occur. On Thursday, October 26, 1995, 5 p.m. CDT, STS-73 MCC Status Report #12 reports: Columbia's crew members participated in two special events during their sixth flight day as the orbiter itself continued to perform problem-free as did science investigations underway in the Spacelab. Early Wednesday Mission Specialist Michael Lopez-Alegria participated in an interview with NBC Newschannel. Also on Wednesday, STS-73 crew members gathered in the shuttle's middeck and taped the ceremonial first pitch that will open Game Five of the World Series Thursday night in Cleveland, Ohio. The taped message and the first pitch will be played on the "Jumbotron" screen at Jacobs Field in Cleveland and viewed by a nationwide audience on ABC-TV. Commander Ken Bowersox wished the Atlanta Braves and the Cleveland Indians good luck before he threw the slow-spinning pitch, marking the first time a World Series first pitch thrower has not been in the ballpark to make the pitch. Columbia's astronauts will sign the on-board baseballs and give them to Major League Baseball to be enshrined in the Baseball Hall of Fame in Cooperstown, N.Y. Crew members on the Red Team mark the end of their work day at 6:38 p.m. CDT and will return to their work shift in the Spacelab at 6:38 a.m. Columbia is in a 169 by 164 statute mile orbit, completing a revolution of the Earth each 90 minutes. STS-73 Flight Day 7 Highlights: On Thursday, October 26, 1995, 8 a.m. CDT, STS-73 MCC Status Report #13 reports: Research work continued on schedule overnight aboard Columbia as the crew also continued a schedule of staggered half-days off duty to relax from the around-the-clock operations. Mission Specialist Cady Coleman and Payload Specialist Fred Leslie each had a half-day off during the night. The Red Team of crew members is now at work aboard Columbia, having begun their 12-hour shift at 6:38 a.m. CDT Although it had no effect on the research work, a ground system problem caused two extended communications outages between Columbia and the ground during the night. The time frame for the outages was known in advance by Mission Control and the crew was informed. All data from the experiments and the shuttle itself during the communications loss was recorded aboard Columbia and has since been played back to the ground. The communications loss was due to an equipment failure at the ground terminal for NASA's tracking and communications satellites. The failure prohibited communications using the eastern Tracking and Data Relay Satellite (TDRS-E), a satellite stationary above the Atlantic Ocean used during about the last one-third of each orbit by Columbia. On two successive orbits during the early morning hours, communications were unavailable on TDRS-E, the first time for about 36 minutes and the second time for about 27 minutes, while the ground equipment was being repaired. Columbia is in a 169 by 165 mile orbit, completing a revolution of Earth every 90 minutes. The spacecraft remains in excellent condition, and there are no issues of concern in Mission Control regarding its performance. On Thursday, October 26, 1995, 6 a.m. CDT, STS-73 Payload Status Report #10 reports: (5/21:07 MET) Crew activities were relatively quiet aboard the second United States Microgravity Laboratory overnight, as Mission Specialist Cady Coleman and Payload Specialist Fred Leslie took turns getting a few hours rest from their busy schedules. The mission's many crystal growth experiments continued uninterrupted, taking advantage of unique opportunities for discovery available only in the low-gravity environment of space. The Crystal Growth Furnace team finished melting Dr. David Matthiesen's gallium arsenide crystal and began slowly resolidifying the semiconductor sample. At almost 2,300 degrees Fahrenheit (1,255 degrees Celsius), the furnace is operating at the highest temperature it will reach during the mission. A new Crystal Growth Furnace feature for USML-2 will periodically mark the point where the melted material is solidifying with an electric pulse. When the crystal is analyzed after landing, the marks will indicate the exact growth rate of the crystal and the location of the solid/liquid boundary at each stage of solidification. Electronic devices using gallium arsenide semiconductors, such as high-speed digital circuits, operate at higher speeds and use less power than those using silicon crystals. Matthiesen's experiment investigates techniques for uniformly distributing a small amount of selenium within the crystal as it grows in microgravity. "There is less than one part per million of selenium in this sample," said furnace team member Dr. Frank Szofran of Marshall Space Flight Center. "Yet it greatly alters the electrical conductivity of the semiconductor." Trace materials, called dopants, are often added to semiconductors to improve or precisely control their electronic characteristics. To produce high quality crystals, scientists need to understand the process by which dopants are distributed within a compound during crystal growth. Growing the crystals in microgravity greatly reduces uneven dopant distribution caused by gravity on Earth, allowing more subtle influences to be identified. Leslie and Coleman spent most of their on-duty hours working with the Surface Tension Driven Convection Experiment (STDCE). Last night's runs were the first to use the experiment's largest chamber, almost 1-1/4 inches (3 centimeters) in diameter. As they have for the past five days, the science team in Huntsville and the Spacelab crew on orbit worked together to precisely adjust temperatures on the silicone oil surface. Again, they were able to pinpoint when surface-temperature-driven flows within the fluid became unsteady, or oscillatory. This was the first time oscillatory flows had ever been observed in such a relatively large container. Coleman reported seeing especially dramatic, wave-like oscillations near the center of the fluid flow during some of her experiment runs. Unwanted fluid flows affect the quality of materials solidified from a molten state on Earth. Understanding the subtle factors which control those flows gives researchers tools for eventually controlling them. Several factors are contributing to the success of the USML-2 surface-tension experiments. A new optics system developed by Dr. H. Philip Stahl and students from Rose Hulman Institute of Technology in Terre Haute, Indiana, gives the crew and ground controllers precise pictures of oil surface shapes and flow patterns. Spacelab's new six-channel Hi-Pac Television system is simultaneously downlinking video of those images, along with a three-dimensional view of the chamber and infrared temperature readings, giving the science team a complete representation of the experiment. STDCE team members also have been keeping a close eye on real-time data from the Three-Dimensional Microgravity Accelerometer, or 3-DMA. The low-frequency vibration detector has a sensor located in the rack next to the surface tension experiment. "3-DMA allows us to make a judgment as to whether to wait for external movements to settle down before beginning an experiment run," said Project Scientist Alex Pline. On its first Shuttle flight, 3-DMA was developed as a low- cost commercial accelerometer system by the University of Alabama at Huntsville's Consortium for Materials Development in Space. The instrument measures both the absolute level of microgravity acceleration (the difference between zero acceleration and what is experienced during the mission) and microvibrations which could affect the investigations onboard. Principal Investigator Jan Bijvoet worked in Huntsville for the European Space Agency when it was developing the Spacelab over a decade ago. "It's good to have an experiment aboard 'my' Spacelab," he said. The Geophysical Fluid Flow Cell Experiment team is wrapping up another six-hour solar atmosphere simulation, and growth continues in the Zeolite Crystal Growth Furnace and the many USML-2 protein crystal growth experiments. On Thursday, October 26, 1995, 5 p.m. CDT, STS-73 MCC Status Report #14 reports Work on board the Space Shuttle Columbia continued to go smoothly as members of the Red Team monitored orbiter systems and conducted scientific experiments in the Spacelab. Red Team members spent their seventh flight day working diligently in the science lab which is nestled in Columbia's cargo bay. The Red Team will wrap up its day at 5:38 p.m. CDT, a little earlier than they have the last few days. They will hand over to Blue Team members who will continue work in the Spacelab. The Red Team will return to duty at 5:38 a.m. CDT. Friday's scheduled telelvision events include: an ABC "World News Now" interview at 8:23 a.m. with STS-73 Commander Kenneth Bowersox and Payload Commander Kathyrn Thornton; Mission Update at 11:30 a.m.; and a Mission Status Briefing at 1 p.m. Columbia is in a 169 by 165 mile orbit, completing a revolution of Earth every 90 minutes. The spacecraft is in excellent condition and flight controllers did not have any issues they are working regarding the orbiter's performance. On Thursday, October 26, 1995, 6 p.m. CDT, STS-73 Payload Status Report #11 reports: (6/09:07 MET) Payload Commander Kathy Thornton and Payload Specialist Al Sacco had a busy day conducting a wide variety of experiments in the microgravity environment aboard the Shuttle Columbia in the second United State Microgravity Laboratory (USML-2). The Colloidal Order-Disorder Transition experiment, an investigation into the solidification process in crystal growth, revealed unexpected results today. In studying electronic still photographs provided by Sacco this morning, researchers saw that crystals of varying sizes were formed in the samples. This is something they haven't seen on Earth. Sacco told researchers on the ground that particles in the 15 sample vials were randomly spaced, and ranged in size from 10 to 150 microns (millionth of a meter). Scientists are interested in what happens at the boundaries between solid and liquid states during crystallization of a colloid, allowing them to see how atoms and molecules move and arrange themselves when they form a crystal. This may help improve materials processing methods on Earth, as well as in microgravity. A crystal of the semiconductor material gallium arsenide has grown about 1 inch (2-1/2 centimeters) since it was placed in the Crystal Growth Furnace last night. The temperature in the Crystal Growth Furnace is the hottest it has been during this mission' between 22 and 23 hundred degrees Fahrenheit . The crystal is growing at a rate of 1.8 millimeters per hour. Although this is a slow growth period, gallium arsenide crystals have the potential to make computers, satellites and other electronics work much faster than with silicon chips. Chips made of gallium arsenide are now too expensive for widespread use - current processing techniques yielding only one good chip out of every ten that are made. Thornton this morning began deploying liquid drops in the Drop Physics Module in tests to help the science team finalize a procedure to slow down the rotation of the drops. Later, the USML-2 crew will add a small amount of chemical, called a surfactant, to the drop in an experiment known as Science and Technology of Surface Controlled Phenomena, managed by Principal Investigator Dr. Robert E. Apfel, of Yale University. Scientists are comparing characteristics of drops containing surfactants to drops of pure water. Surfactants are substances which alter the surface properties of a liquid, aiding or inhibiting the way it adheres to or mixes with other substances. Applications of this research apply to many industrial processes, among them the production of cosmetics and improvement of oil recovery. University of California's Riverside's Dr. Alex McPherson is principal investigator for the handheld diffusion test cells experiment. The experiment is growing proteins by liquid- liquid diffusion, a process in which fluids diffuse into each other by random motion of molecules, rather than being mixed together. This method is difficult on Earth because gravity causes solutions with different densities to mix. The experiment is a precursor for long-duration crystallization experiments aboard the International Space Station and Mir. The Three-Dimensional Microgravity Accelerometer experiment ground support team continues to troubleshoot the cause and resolution of a data downlink problem. This has not impacted science since all data is recorded onboard the Shuttle. This experiment measures accelerations and vibrations that could affect investigations in the Spacelab. Thornton spent the afternoon working with the Surface Tension Driven Convection Experiment. Researchers on the ground relayed instructions for Thornton to raise the temperature of the silicon oil surface in order to study the change from steady thermocapillary fluid flows to oscillatory (or unsteady) flows. This investigation could one day lead to better, stronger high-tech crystals, metals, alloys and ceramics. Sacco spent the last part of his shift working in the Glovebox activating new protein crystal growth experiments, based on his observations of results from previous experiments. An advantage of a longer mission like USML-2 is that it allows science teams on the ground to perform several experiment runs, analyze their data, and have the crew devise a new set of experiments. This allows investigators to quickly capitalize on their observations in real time. STS-73 Flight Day 8 Highlights: On Friday, October 27, 1995, 8 a.m. CDT, STS-73 MCC Status Report #15 reports: Flight controllers in Houston had a quiet shift last night as orbiter systems continue to perform well, allowing work on board the Space Shuttle Columbia continue uninterupted. Red Team members are now spending their their eighth day in space. Earlier this morning, Commander Ken Bowersox and Payload Commander Kathy Thornton took a moment to talk to ABC's World News Now about the progress of the flight and life on board Columbia. In response to a question about the living conditions on the orbiter, Thorton explained that the extra space provided by the Spacelab laboratory module and the fact that the crew is split into two teams for 24-hour payload operations, makes the living space quite comfortable. On Friday, October 27, 1995, 6 a.m. CDT, STS-73 Payload Status Report #12 reports: (6/21:07 MET) "We feel like we're back home at Marshall in the Payload Crew Training Complex," said Mission Specialist Cady Coleman last night, referring to the Marshall Space Flight Center Spacelab mockup where she and her crewmates spent many hours preparing for the second United States Microgravity Laboratory mission. Overnight, Coleman and Payload Specialist Fred Leslie performed now-familiar duties with protein crystal growth and fluid flow experiments, and also tested a new vibration- isolation facility. Coleman completed the mission's first technical demonstration with the Suppression of Transient Acceleration by Levitation Evaluation, or STABLE. Developed cooperatively by the Marshall Space Flight Center and McDonnell Douglas, STABLE is the first facility to use electromagnetic levitation to isolate sensitive experiments from disturbances in the Shuttle. Coleman activated a simple experiment within the levitation device by heating a fluid-filled cell, then observed it with a laser light. To the delight of the science team in Huntsville, the experiment's small optical system recorded the resulting heat diffusion. This experiment, known as "CHUCK," was designed in Marshall's Space Sciences Lab as a small, simple system to study materials processes in microgravity that are applicable to crystal growth mechanics. For the first run, the STABLE platform floated free through the action of electromagnets. The platform was locked in place for a repeat run. Comparisons should help determine the effectiveness of STABLE for reducing background vibrations. Both STABLE and CHUCK were produced in less than five months, from the time designers got the go-ahead for construction this past January until they delivered the equipment to Kennedy Space Center in June. Engineers on these projects were working under a new NASA committment to streamline the development of lower cost space hardware. Later in the shift, Coleman examined growing protein crystals under the Glovebox microscope. Commercial Protein Crystal Growth team members watched downlink video of the magnified crystals from their home lab at the University of Alabama in Birmingham. Coleman reported that the crystals were bigger and seemed to be growing in isolation rather than in clumps. One crystal in particular was so well-formed that the fist look at it elicited applause from the Birmingham team. Coleman then activated more samples of the same proteins based on observations of growth progress thus far. She jokingly told the experiment team that she has given up caffeinated coffee just for them, "since you have to be so careful with these things," referring to the delicate handling required for protein crystals. The Glovebox protein crystal growth evaluation is one of several USML-2 experiments aimed at determining the best methods for growing protein crystals. In the middeck, the European Space Agency's Advanced Protein Crystallization Facility is growing protein crystals by three different methods. An internal camera is recording video images of the growing crystals. After the mission, researchers will study development of the crystals in microgravity to determine why and how proteins nucleate and begin to form crystals. A decade of Shuttle protein crystal growth experiments has led to improved methods for ground-based experiments, as well as producing well-ordered crystals which have allowed the structures of several proteins to be determined. Understanding the structures of proteins, such as those related to diseases, is important for developing custom- tailored molecules, such as drugs, to interact with them. As has been true for the majority of the mission, Leslie spent most of his shift working with the Surface Tension Driven Convection Experiment. The Lewis Research Center investigation is gathering extyensive new data on subtle fluid flows created by surface temperature variations. In a typical operation, Leslie drew down the volume of silicone oil within a 1-1/4 inch (3 centimeter) cylinder until it formed a deeply concave surface -- a surface shape possible only in microgravity with a container this large . Leslie heated the fluid, first very steadily, and again in several pronounced steps. The Case Western Reserve University science team reported seeing distinct differences in the heating power levels at which fluid flows became unsteady, or began to oscillate, with the two heating scenarios. A thorough understanding of fluid physics forms a valuable base for improvements in sophisticated materials processing. Also last night, Coleman reset a Drop Physics Module circuit breaker which tripped yesterday when some film jammed, and the facility is ready for experiment operations later today. More Surface Tension Driven Convection Experiment runs are also scheduled. Growth of a gallium arsenide semiconductor within the Crystal Growth Furnace will continue until early tomorrow morning. On Friday, October 27, 1995, 5 p.m. CDT, STS-73 MCC Status Report #16 reports: Systems on board the Space Shuttle Columbia continue to work well despite a temporary glitch concerning two steering jets. About 1:15 p.m. CDT two vernier jets - R5R and R5D - failed off at the same time. However, about 40 minutes later, after ground controllers reviewed data, the crew hot fired the jets and they were recovered. There was no loss of science data and minimal impact on the day's activities. Each orbiter has 38 primary thrusters and six smaller vernier thrusters which provide vehicle steering. Shortly after the two vernier jets failed this afternoon, the crew took the orbiter from a gravity gradient attitude, which requires sporadic firing of steering jets, to free drift. Columbia had been flying in a gravity gradient attitude - which has the tail of the orbiter facing the Earth and its nose facing deep space - to minimize shuttle movement in support of science operations in the Spacelab, particularly the growth of protein crystals. The temporary loss of the two vernier jets occurred while crystals growing in the Spacelab were cooling down so there was no impact on the experiment. Early this afternoon crew members also downlinked views of a ding in one of the orbiter's front windows. There are six windows along the front of the orbiter, three on the commander's side and three on the pilot's side. The ding was in the center window on the commander's side or the second window from the left. Shuttle windows encounter dings from orbital debris or natural material such as meteoroids from time to time. The dings are analyzed by scientists after the shuttle has landed to determine size and material source. JSC debris scientists said the largest ding returned on a shuttle window thus far occurred on STS-59 in April 1994. The ding measured one-half an inch in diameter and was caused by an orbiting paint chip. Based on what they saw in the downlinked video, scientists estimated the Columbia's ding was most likely no larger than about one-eighth of an inch across, but said exact measurements and a determination of the source material would have to await the shuttle's return to Earth. Columbia is in a 169 by 165 mile orbit, completing a revolution of the Earth every 90 minutes. On Friday, October 27, 1995, 6 p.m. CDT, STS-73 Payload Status Report #13 reports: (7/09:07 MET) Lead scientists for two USML-2 investigations, Astroculture and the Geophysical Fluid Flow Cell Experiment, showed experiment pictures to the crew early this morning, via the new Ground-to-Air Television uplink being tested on this mission as STS 73 completed its first week in space. "This is the first time that crop plants have been grown to produce edible food in space," observed Astroculture co- investigator Dr. Theodore Tibbitts. Also, for the first time, scientists have been able to obtain data on respiratory cycles and starch accumulation for plants in a NASA controlled space environment. Starch is an important nutrient in plants, and these measurements will tell whether space-grown potato tubers have the same nutritional value as their Earth-grown counterparts. The benefits of having plants in space go well beyond providing a food source. Plants will provide a naturally recycling life support system in space by helping remove excess carbon dioxide and replenishing oxygen, and by providing a natural way to purify water in a space-borne habitat. Astroculture Principal Investigator Dr. Raymond Bula of the University of Wisconsin in Madison pointed out leaf patterns in a photo of potato plants growing in the plant growth chamber aboard the Shuttle. "The thing that's been exciting to us is that, in the three images that have come down at different times, the leaves are in the same position. This means that the plants are healthy. If they had been having problems, the leaves would have shifted," Bula said. "This is all kind of new and exciting stuff," explained Dr. John Hart of the University of Colorado in Boulder, principal investigator for the Geophysical Fluid Flow Cell, while showing the crew a time lapse movie of simulated solar atmospheric flows. The movie was made from the still photo images, snapped every 45 seconds, of fluid flows within the facility's rotating hemisphere. "You can see a lot of the evolution of these solar dynamic flows we've been interested in, and we've seen some surprising turbulence," Hart told the crew. "We are comparing these results with our computer simulations and other theoretical ideas to understand the extensive turbulence which starts near the polar region and spreads rapidly toward the equator." This morning, the GFFC simulated the long-term changes that will eventually occur in the Sun. Payload Specialist Dr. Al Sacco began his shift operating the Surface Tension Driven Convection Experiment Apparatus. Throughout the day, researchers on the ground relayed instructions for Sacco and Thornton to manipulate the temperature of the silicon oil surface in order to study the change from thermocapillary fluid flows to unsteady flows. This investigation could one day lead to better, stronger high-tech crystals, metals, alloys and ceramics. Working in the Glovebox, Sacco had an opportunity to demonstrate the device's versatility, growing protein crystals in the morning then switching to zeolites in the afternoon. The system can offer one or two levels of containment for toxic materials, liquids and particles. It can operate with gloves for full containment, sleeves for more sensitive surgical glove operation or with all doors removed as an open workbench observation platform. Al Sacco is principal investigator for two USML-2 investigations into the growth of zeolite crystals, widely used as catalysts and filters in the chemical processing industry. A crystal of the semiconductor material gallium arsenide has finished the crystal growing portion of the processing cycle in the Crystal Growth Furnace. The crystal grew to more than two inches in length and will continue cooling until being removed tomorrow morning. After cooling, the crystal will be removed from the furnace and stored using a flexible glovebox. Gallium arsenide is used in high-speed digital circuits, solid-state lasers, and a variety of other applications. Al Sacco worked at the Drop Physics Module, manipulating liquid drops treated with a surfactant, or substance that changes the properties of liquid surfaces. Two drops were deployed and brought together until they coalesced, or merged to form a single drop. The surfactant, called Bovine Serum Albumin, is an organic protein typically used in chemical processing. Sacco twice succeeded in making the drops coalesce. "These are the first and best drop coalescences we've ever had," said DPM co-investigator Dr. Eugene Trinh of NASA's Jet Propulsion Laboratory, adding, "it went very nicely." The Drop Physics Module allows investigators to study large drops in which dynamic phenomena (such as coalescence) are slowed down and more easily seen. They can observe how flows inside a drop and the drop's surface interact to provide a variety of dynamic events. This fundamental knowledge can be beneficial for a variety of industries on Earth, from pharmacology to industrial chemistry. STS-73 Flight Day 9 Highlights: On Saturday, October 28, 1995, 8 a.m. CDT, STS-73 MCC Status Report #17 reports: The Space Shuttle Columbia continues to perform well on its 18th mission, allowing crew members and flight controllers time to concentrate on the United States Microgravity Payload experiments. This morning, Columbia passed the midway mark of its marathon mission. Flight controllers in Houston had another quiet shift last night with orbiter systems functioning normally. This gave the team plenty of time to fine tune the timeline for the Red Team's ninth day in space. Columbia's smooth operation also is allowing orbiter crew members to assist in the science operations in the Spacelab module. On Saturday, October 28, 1995, 6 a.m. CDT, STS-73 Payload Status Report #14 reports: (7/21:07 MET) Mission Specialist Cady Coleman and Payload Specialist Fred Leslie took turns conducting investigations within the European Space Agency's versatile Glovebox enclosure as the second United States Microgravity Laboratory-2 mission reached its half-way point. Leslie worked with two Glovebox investigations sponsored by NASA's Lewis Research Center in Cleveland, Ohio. First, he photographed several containers holding different concentrations of microscopic plastic spheres suspended in liquid for the Colloidal Disorder- Order Transition experiment. Dr. Paul Chaikin of Princeton University hopes to determine at which concentration the collisions between the spheres change the mixture from a disordered fluid state, with the spheres moving haphazardly, to an ordered crystalline state in which they are arranged in a symmetrical way. "We are studying the most fundamental transition between liquid and solid states, to find what is really important in the formation of solids and crystals," said Chaikin. The behavior of the spheres in space, essentially free from the disruption of gravity, is a basic model for the way atoms interact with one another. All physical properties of matter such as weight, hardness and color are determined by the kind of atoms present and how they interact. Leslie's next Glovebox activity, the Interface Configuration Experiment, studied the behavior of a fluid in microgravity as it filled a specially shaped chamber. Glovebox Investigator Dr. Paul Concus of the University of California at Berkeley and Co- Investigators Dr. Robert Finn of Stanford University, and Mark Weislogel of NASA's Lewis Research Center watched live video as ruby-tinted fluid began flowing into three containers, each with slightly different internal angles. The scientists were able to see definite differences in the way the fluid adhered to chamber walls in the various containers, and some of the behavior was different from that predicted by the classic mathematical model. "This shows that we cannot rely completely on the current theory of how surfaces form in low gravity, which is based on an equation developed in the 1800's," said Weislogel. "We saw that physical factors which are not included in the purely mathematical theory do indeed play a significant role." Insights will aid design of fluid systems for space such as those for liquid fuels. Coleman activated more proteins for the Glovebox Protein Crystal Growth experiment, this time using larger drops of protein solution. She has initiated growth of new protein samples during several recent shifts, adjusting conditions based on the progress of previously activated crystals. This hands-on involvement of crew members will help Dr. Larry DeLucas of the University of Alabama at Birmingham determine the best growth methods for various proteins during future Shuttle and Space Station experiments. Mission Specialist Mike Lopez-Alegria deactivated a crystal growth chamber for a portion of Dr. Dan Carter's Protein Crystallization for Microgravity Apparatus experiment. This was one of eight chambers, activated early in the flight, which contain two salt solutions rather than actual proteins. The two solutions, with different concentrations of salt, will gradually diffuse into one another until the salt concentration is uniform. The crew is deactivating one container about every two days to detect the point in time when the diffusion is completed. Carter will use results to estimate the rate at which solutions will diffuse during actual protein crystal growth experiments in microgravity. "We know that proteins grow more slowly in space than on Earth, but we don't know why," said protein specialist Brenda Wright of Marshall Space Flight Center. "We've wanted to do an experiment for a long time that would help us predict the rate at which certain crystals will grow, so we can be more efficient with these valuable proteins and our time in orbit. But up until now, we haven't had the room to fly anything but actual proteins." Because Carter's apparatus holds many times more samples in the same volume of space than traditional crystallization facilities, room was available for the test on USML-2 . Scientists use the well-formed crystals grown in space to analyze protein structures, a key to determining how these "building blocks of life" function in the human body and other biological systems. Early this morning, Lopez-Alegria rolled the orbiter's position about 17 degrees to put its left wing directly into the path of flight, an attitude the Geophysical Fluid Flow Cell (GFFC) experiment scientists believe might further reduce disturbances to its experiment. The Shuttle will maintain that orientation until about 8 a.m. CDT. The fluid flow cell team is running solar atmosphere simulations at a slower rotation, to determine if the special Shuttle attitude makes a discernible difference. The facility uses a combination of rotation, temperature and gravitational variables to simulate fluid flows in the atmospheres of the sun and planets. The Suppression of Transient Acceleration by Levitation Experiment, or STABLE, completed its final run for the mission during the Shuttle maneuver. After the mission, a Marshall Center team will analyze video of a small experiment inside the levitation device to see if STABLE isolated the experiment from disturbances as the orbiter changed position. On Saturday, October 28, 1995, 5 p.m. CDT, STS-73 MCC Status Report #18 reports: With all continuing to proceed smoothly aboard Columbia on the 72nd Space Shuttle mission, the seven astronauts that make up this microgravity laboratory mission have passed the mid-point of the flight. A short while ago, four the crew members completed their ninth workday in space and were relieved by the remaining three astronauts. The crew is split into two shifts working around the clock to support the many experiments that make up this second dedicated United States Microgravity Laboratory mission. Ken Bowersox, Kent Rominger, Kathy Thornton and Al Sacco turned in for the evening about 6 p.m. and are scheduled to take over for Mike Lopez-Alegria, Cady Coleman and Fred Leslie about three tomorrow morning. STS-73 Flight Day 10 Highlights: On Sunday, October 29, 1995, 9 a.m. CDT, STS-73 MCC Status Report #19 reports: After spending eight hours with its belly pointed toward the sun, Columbia is back in position to support the sensitive United States Microgravity Laboratory-2 experiments. For this mission, Columbia's normal attitude has its left wing pointing in the direction of travel and its tail pointed toward the Earth. This attitude, however, exposes some portions of the orbiter to the extreme cold of space for long periods of time. To keep the pressure in the tires at the levels necessary to support landing operations, the flight control team is implementing its pre-flight plan for "thermal conditioning" of the cold areas. The maneuver, which will be conducted four times during the mission, calls for crew members to reposition Columbia so that the sun shines directly on the lower portion of the orbiter. At the conclusion of the first conditioning period, the tire pressure was measured at 334 pounds per square inch (psi), an increase from 328 psi before the period. The nominal end of mission pressure is targeted at 330 psi. On Sunday, October 29, 1995, 6 a.m. CDT, STS-73 Payload Status Report #15 reports: (8/21:07 MET) Research in the unique laboratory environment of space continued at a steady pace over the last 24 hours aboard the second United States Microgravity Laboratory. During one experiment run yesterday, the Surface Tension Driven Convection Experiment team observed a phenomenon that had never been seen before. Fluid flows were erratic, with no obvious organization or pattern, as Payload Commander Kathy Thornton increased the silicone oil surface temperature beyond the point at which flows within the fluid began to oscillate, or become unsteady. Overnight, the ground team conducted several test runs remotely from the Spacelab control center, freeing the crew for other activities. The experiment seeks to define the factors which cause subtle, surface-temperature-driven fluid flows to become oscillatory. Researchers from Case Western Reserve University in Ohio will use the extensive data gathered during USML-2 to graph the onset of oscillations under many conditions. A better understanding of how and why such fluid flows occur will be valuable for industrial applications from fuel management and storage to materials processing methods such as welding. In a related Glovebox investigation, Payload Specialist Fred Leslie performed the mission's first run of the Oscillatory Thermocapillary Flow Experiment. Though it uses much simpler equipment, the purpose and procedure are similar to Surface Tension Driven Convection Experiment tests. The major difference is the proportions of the container. The STDCE chamber's diameter is twice its own height, while this Glovebox investigation used a very shallow chamber with a diameter four times its height. Different chamber sizes provide even more variables for determining the onset of unstable surface-temperature-driven fluid flows. Thornton and Payload Specialist Al Sacco exchanged sample cartridges in the Crystal Growth Furnace yesterday, replacing three processed samples with three new ones. Last evening, the facility completed its shortest crystal growth cycle, depositing a thin layer of infrared-detecting mercury cadmium telluride on a base material, or substrate, in just one and a half hours. "We're examining ways to reduce what we call crystal 'birth defects,' which are transferred from defects in the substrate material which can't be eliminated," said Principal Investigator Dr. Heribert Wiedemeier of the Rensselaer Polytechnic Institute. "In the crystal we grew on USML-1, the interface between the substrate and the first layer was much smoother than in crystals produced on the ground. This was totally new, something we had never seen before and had not expected." On USML-2, Wiedemeier is growing much thinner layers to see how far substrate defects propagate into the first crystal layer. On the ground, the crystal material first forms separate "islands" on the base, which join to form a complete layer after about two hours of growth. Wiedemeier grew his first USML-2 crystal on Sunday for two and one-half hours to be sure a compete layer was produced. "With last night's sample, we deliberately stopped growth in less time than it takes for a layer to form on Earth. However, there is a good chance that under microgravity we may get a complete layer in the shorter time period," he said. If this mission demonstrates that certain reduced convection conditions produce more uniform initial layers in a shorter growth time, Wiedemeier feels it could lead to crystal growth methods on Earth that are faster, require less material and energy, and therefore are less costly. Sacco completed activating protein crystal growth experiments in the Glovebox facility yesterday afternoon. Thus far, more than 50 individual experiments have been set up using seven different proteins -- from viral disease proteins to several involved in the human immune system. USML-2 crew members will observe the samples on Thursday to monitor the growth of the crystals. Proteins play vital roles in daily life, from providing nourishment to fighting disease. Many areas of biotechnology benefit from new information on the structure of proteins, such as development of food crops with higher protein content and basic research toward more effective drugs. Team members for the Geophysical Fluid Flow Cell Experiment slowed down the rotation of their experiment hemisphere to get additional data which relates to fluid motions in Earth's core -- motions that cause such phenomena as the forced drift of the Earth's continents. The fluid flow cell is an investigation in fluid dynamics that models fluid flows in planets, stars and oceans, using silicone oil between two rotating hemispheres. Controllers can vary electrical charges which simulate gravity, as well as fluid temperature and rotation speed of the hemispheres, to reflect conditions in different environments. Overnight, Mission Specialist Cady Coleman patiently worked through problems with computer equipment to complete several runs of the Glovebox Colloidal Disorder-Order Transition (CDOT) investigation. CDOT uses microscopic plastic spheres suspended in a liquid to model the behavior of atoms. As planned, red shift crew members will complete the CDOT activities later today. When he came back on duty early this morning, Payload Specialist Al Sacco began a series of experiments in the Drop Physics Module to examine how chemical additives, called surfactants, affect liquid drop behavior. The drop studies will continue throughout today's shift. STS-73 Flight Day 11 Highlights: On Monday, October 30, 1995, 8 a.m. CST, STS-73 MCC Status Report #20 reports: On its eleventh day on orbit, the Space Shuttle Columbia continues to provide the United States Microgravity Laboratory-2 with a stable platform above the Earth for the astronauts to conduct a myriad of experiments. Flying at an altitude of 170 miles, Columbia is positioned with its tail pointing toward the Earth and its port wing pointing in the general direction of travel. This "gravity gradient" attitude is maintained with only minimal thruster firings. The orbiter will stay in this position until around midnight tonight when Columbia will begin a 14-hour thermal conditioning period with its belly pointed toward the sun. On Monday, October 30, 1995, 6 a.m. CST, STS-73 Payload Status Report #16 reports: (9/21:07 MET) Drop physics studies and Glovebox investigations dominated crew activities during the tenth day in orbit for the United States Microgravity Laboratory-2, while the mission's many remotely controlled experiments collected valuable data as well. Geophysical Fluid Flow Cell (GFFC) experiment runs yesterday seem to validate predictions in a mathematical model of planetary and solar fluid flows designed by Co-Investigator Dr. Tim Miller. GFFC scientists saw different heat-driven, or thermocapillary, flow patterns when the same conditions were initiated at different rates. For instance, voltage, temperature and rotation speed parameters applied slowly to the experiment's silicone-oil-filled hemispheres produced one thermocapillary fluid flow, and a different flow resulted when the same parameters were applied to the experiment quickly. "These particular flows are relevant to cases where you might have a planet with a core that's still moving around -- still convecting -- and also planets with atmospheres that are rotating very slowly," said Miller. The experiment facility, which simulates fluid flows in oceans, planets and stars, is operated from the ground with only occasional adjustments and monitoring by the crew. Research in thermocapillary flow phenomena could one day aid in forecasting ocean flows and weather patterns. The Crystal Growth Furnace finished melting its second gallium arsenide semiconductor sample yesterday afternoon, then began slowly moving the furnace module down the length of the sample cartridge to solidify the crystal. Early this morning, the experiment team changed the furnace translation rate from seven one hundredths of an inch (1.8 millimeters) per hour to seven tenths of an inch (18 millimeters) per hour. This ten-fold increase will help Principal Investigator Dr. David Matthiesen determine whether the solidification rate influences the formation of bubbles in semiconductor crystals. Gallium arsenide crystals promise important advantages for electronic applications, operating at high speeds and using less power than traditional silicon semiconductors. Over the past 24 hours, Payload Commander Kathy Thornton, Payload Specialist Al Sacco and Mission Specialist Cady Coleman conducted a series of Drop Physics Module experiment runs for Dr. Robert Apfel of Yale University. The experiment examines the influence of chemicals called surfactants on the behavior of liquid drops. Surfactants are substances that migrate toward the free surfaces of liquids, resulting in a reduction of surface tension, or a weakening in molecular "skins." For instance, soap contains surfactants which makes water "wetter." The various crew members levitated different sized drops containing surfactants, then squeezed them with sound waves. Drop Physics Module team members observed the drops' oscillations and surface distortions from two perspectives, both of which were transmitted to the ground simultaneously by Hi-Packed Television. Dr. Apfel used results from related USML-1 experiments to confirm and adjust theoretical models. This mission's experiments will help him refine these theories, which apply to processes as widespread as the production of cosmetics to the recovery of oil spills and environmental cleanup. Sacco performed operations for the Colloidal Disorder-Order Transition investigation, a Glovebox study which seeks to answer fundamental questions about how liquids become solids. Tiny spheres suspended in a fluid were clustered together in crystallized formations, in a model of how atoms arrange themselves to transition from liquid to solid states. Research of this type could lead to improvements in materials processing on Earth, such as developing micromachines or better surgical tools. The science team expects to get at least a 90 percent return on science from their data, despite time lost troubleshooting several equipment problems. Payload Specialist Fred Leslie followed up on two Glovebox studies which delve into fundamental factors of fluid behavior. He photographed the position of red fluid inside a mathematically designed, transparent container for the Interface Configuration Experiment. The study examines how angles within a container affect the way fluids shift within it. Leslie also completed the mission's second run of the Oscillatory Thermocapillary Flow Experiment, heating the surface of silicone oil in a container whose depth equaled its diameter. The run successfully pinpointed the transition between steady and unsteady heat-induced fluid flows. The investigation duplicates the Surface Tension Driven Convection Experiment (STDCE), but uses containers with different depths to provide additional insight into the fluid-flow phenomenon. According to Project Scientist Alex Pline, results were consistent with STDCE results from earlier in the mission. The team is building an extensive catalogue of data on these subtle fluid motions which can affect materials processing on Earth. Leslie was unsuccessful in several attempts to coax fuel drops onto a fiber in the Glovebox Fiber Supported Droplet Combustion investigation. The heptane fuel stubbornly adhered to deployment needles, probably due to degradation of the needles' non-stick coating. The Glovebox team is comparing notes with members of other experiment teams and USML-2 payload controllers to identify other non-stick substances aboard which might be substituted. On Monday, October 30, 1995, 5 p.m. CST, STS-73 MCC Status Report #21 reports: Columbia will remain in the "gravity gradient" attitude, with its tail pointing toward the Earth and its port wing in the line of travel, until about midnight tonight when the orbiter will begin a 14-hour thermal conditioning period with its belly pointed toward the Sun. That change in attitude will mark the second of four scheduled thermal conditioning periods designed to warm up some portions of the orbiter that, in the gravity gradient attitude, have been exposed to the extreme cold of space for long periods of time. The thermal conditioning is necessary to warm the orbiter's tires to levels necessary to support landing. The Red Team handed over science operations to their colleagues on the Blue Team at 2:38 p.m. CST. The Blue Team will be on duty until 2:38 a.m. Tuesday when the Red Team returns to work. On Monday, October 30, 1995, 6 p.m. CST, STS-73 Payload Status Report #17 reports: (10/09:07 MET) The USML-2 Crystal Growth Furnace experiment team today successfully grew a crystal of gallium arsenide with a dopant, or impurity, added. Later, the crystal will be tested to determine if the dopant was evenly distributed during the crystal's growth. Slightly more than one-inch (7 centimeters) in length, the semiconductor crystal grew for 12 and one half hours. To produce high-quality gallium arsenide crystals, scientists need to understand the processes by which chemical impurities are introduced, whether intentionally or unintentionally. Electronic devices made from these crystals operate at higher speed and use less power. After setting up the Surface Tension Driven Convection Experiment this morning, Payload Specialist Al Sacco stepped aside and surface tension experiment team members on the ground were able to run the experiment's heater power by remote commanding. Team members observed the experiment performance via a multi-channel digital television link. The remote commanding capability gave the team a chance to get extra data on their experiment, while Sacco and Mission Specialist Kathryn Thornton were working with other investigations. The surface tension experiment studies the transition between steady fluid flows to oscillatory, or unstable, fluid flows. Today's surface tension experiment runs featured a test cell with a spacer disk inserted into the bottom of the chamber. This cut the chamber's depth in half, thereby lowering the amount of fluid in the cell. An increase in power was necessary to push the fluid flows to the transition point, giving the experiment team even more data for discussion and post-mission analysis. Studying surface tension-driven fluid flows holds valuable applications in areas of materials processing such as the production of high-tech crystals, metals, alloys and ceramics. Dr. Robert Apfel with Yale University, whose experiment studies the effect of surfactants, or chemicals, on the surface of a liquid drop in the Drop Physics Module, says the drops' large oscillations, caused by sound waves, have revealed detailed motions in the sample during the experiment runs. Data he has thus far received on his experiment is clear, concise and definitive, allowing him to measure specific oscillation points. He will use this information in post-mission analysis, comparing it to his numerical predictions. Crew members continue to keep an eye on a Spacelab VCR which experienced a brief problem while recording Drop Physics Module data early this morning. The VCR is up and running, and the drop physics team believes all their data was captured on the experiment film magazine when the problem occurred. Sacco spent about two hours this afternoon photographing and filming the progress of experiments in the Commercial Generic Bioprocessing Apparatus, a facility which is used for a wide variety of life-science experiments. The development of the tiny brine shrimp living in the facility are of interest to investigators, as they could shed light on the importance of gravity in human development and aging. The different stages of the growing protein crystals within the facility were also recorded in today's photo session. Proteins are molecules which serve biological functions. Understanding the structure of these molecules gives scientists an idea what other molecules would interact with the protein and change the way it functions, for instance to help cure or treat an illness. STS-73 Flight Day 12 Highlights: On Tuesday, October 31, 1995, 8 a.m. CST, STS-73 MCC Status Report #22 reports: With all orbiter systems and payload activities continuing to run smoothly, members of the STS-73 Red Team are taking a break today from their busy schedule. STS-73 Commander Ken Bowersox and Payload Specialist Al Sacco had their off-duty time during the first part of the Red Team's shift, while Pilot Kent Rominger and Payload Commander Kathy Thornton will have some free time during the second half of the team's day. These "off duty" times are used by the flight control team to keep the crew well rested for the duration of the 16-day mission. Columbia is nearing the end of a 14-hour thermal conditioning period designed to warm the underside of the orbiter and increase the landing gear tire pressure. For the United States Microgravity Laboratory-2 mission, Columbia usually flies in a stable gravity gradient attitude with its tail pointing toward the Earth and its port wing pointing in the direction of travel. The gravity gradient attitude requires only minimal thruster firings to maintain the orbiter's position, but shades the underside of the orbiter where the landing gear is housed. On Tuesday, October 31, 1995, 6 a.m. CST, STS-73 Payload Status Report #18 reports: (10/22:07 MET) The second United States Microgravity Laboratory added to an already bulging "portfolio" of scientific information as it completed an eleventh day in space. "It's really great to be collecting all this data that we've been planning on for so long," said Mission Specialist Cady Coleman as she sent video views of USML-2 experiment facilities to scientists on the ground. Last night's Particle Dispersion Experiment confirmed a theory about the behavior of dust and particle clouds proposed by Glovebox Investigator Dr. John Marshall, who works with the SETI Institute and NASA's Ames Research Center in California. Payload Specialist Fred Leslie agitated several small transparent chambers inside the Glovebox, dispersing particles of volcanic material, rounded quartz, angular quartz or copper within the various chambers. Marshall watched Glovebox video as dispersed particles in each of the chambers gradually clumped together, or aggregated, due to electrostatic attraction. This validates Marshall's hypothesis that aggregation occurs in all dust clouds: the planetary nebulae which coalesce to form stars, global dust storms on Mars, dust clouds from a meteor impact on Earth (such as the one some believe led to extinction of the dinosaurs), and clouds of dust and ash flung into Earth's atmosphere during volcanic eruptions. The particles are drawn together by static electrical charges. Because the resulting clumps are heavier than individual particles, they fall to the ground to cleanse the atmosphere (or move to the center to form stars) more rapidly than would be predicted by gravitational theory alone. The USML-2 investigation built on results of a technology study on USML-1, which tested methods for dispersing small particles in microgravity. "Because of the success of the USML-1 investigation, we were able to flesh out our science objectives and test variables like particle size, density of the cloud, and type of material. All the materials showed a similar propensity to aggregate," said Marshall. Leslie conducted several more runs for the Glovebox Oscillatory Thermocapillary Flow Experiment, this time using a very shallow silicone oil chamber to see how the shallow depth affects the onset of unstable fluid flows. A few small bubbles, introduced into the oil as Leslie filled the chamber, moved in concert with aluminum tracer particles to illustrate fluid flow patterns in the last experiment run. The Glovebox investigation complements the Surface Tension Driven Convection Experiment's probe into the conditions which cause heat-induced fluid flows to become unsteady, or oscillate. Geophysical Fluid Flow Cell Experiment controllers began their first observation scenario simulating the atmosphere of the planet Jupiter. The giant gas planet radiates more heat than it receives from the sun, making its atmosphere of particular interest to Principal Investigator Dr. John Hart and other atmospheric scientists. "These early runs show dramatic changes in flow types with very small variations in the instrument settings," said University of Colorado Team Member Scott Kittelman. Investigations for the remainder of the flight will concentrate on atmospheres like those of the gaseous planets Jupiter, Saturn and Uranus. Hart feels that lessons learned by studying these "gas giants" can be brought forward to apply to fluid flows on the Earth. Early in Coleman's shift, she stretched a "bridge" of liquid between Drop Physics Module injector tips, in an operation designed to profile the chamber's acoustic characteristics. The Jet Propulsion Laboratory facility's four loudspeakers produce precisely balanced sound waves, used to position and manipulate liquid drops within the chamber. The acoustics system was upgraded after USML-1, and the experiment team used last night's runs to refine their understanding of how various acoustic controls affect drop manipulation in microgravity. Mission Specialist Mike Lopez-Alegria made several adjustments to bring fuel deployment needles closer together in the Fiber Supported Droplet Combustion experiment hardware. Glovebox investigators hope this will make it possible to deposit fuel drops onto a stretched fiber during upcoming experiment runs. Yesterday's planned combustion study was thwarted when the needles would not come close enough to the fiber for the fuel to adhere to it. The Crystal Growth Furnace has cooled down, after processing Dr. David Matthiesen's gallium arsenide semiconductor crystal. The furnace is beginning to melt the next sample, another cadmium zinc telluride semiconductor crystal for Dr. David Larson. This sample is contained in a modified ampoule designed to force the crystal to adhere evenly to chamber walls, further reducing defects. As they have throughout the mission, the Space Acceleration Measurement System (SAMS) and the Orbital Acceleration Research Experiment (OARE) tracked accelerations caused by movements and vibrations within the Shuttle, as well as by Shuttle maneuvers and atmospheric drag. Both are part of the Lewis Research Center's Principal Investigator Microgravity Services project, which provides information to help space scientists evaluate effects of accelerations on sensitive microgravity experiments. Both instruments make continuous records of accelerations for analysis after the flight. In addition, OARE is providing profiles of relatively steady, or low-frequency, accelerations to the USML-2 mission scientist every 12 hours. A Spacelab video cassette recorder which malfunctioned briefly yesterday morning is back to normal operations, with no loss to USML-2 science data collection. On Tuesday, October 31, 1995, 5 p.m. CST, STS-73 MCC Status Report #23 reports: Shortly after 11 a.m. CST, crew members reported they were unable to see the Cosmos 398 because of bright sunlight although the shuttle passed within about 75 statute miles of the spacecraft. The Cosmos 398 is an old Soviet lunar module now circling the Earth at a lower orbit than the shuttle. It was launched into orbit by the former Soviet Union in 1971 and, due to program changes, was left in space. About 1:04 p.m. ended its 14-hour thermal conditioning period and returned to a gravity gradient attitude. Tuesday's conditioning period marked the second of four planned warm-up sessions. The thermal conditioning periods are designed to warm the underside of the orbiter and subsequently increase the landing gear tire presssure. For the United States Microgravity Laboratory-2 mission, Columbia usually flies in a stable gravity gradient attitude with its tail pointing toward the Earth and its port wing pointing in the direction of travel. The gravity gradient attitude requires only minimal thruster firings to maintain the orbiter's position, but shades the underside of the orbiter where the landing gear is housed. The remaining two warm-up sessions are targeted to occur on Thursday and Friday. The Red Team handed over mission activities to their colleagues on the Blue Team at 2:38 p.m. CST and will resume their work at 2:38 a.m. Wednesday. On Tuesday, October 31, 1995, 6 p.m. CST, STS-73 Payload Status Report #19 reports: (11/09:07 MET) USML-2's Crystal Growth Furnace has finished melting a second sample of the semiconductor material cadmium zinc telluride, and the crystal has begun to solidify. This crystal is being slowly solidified in one direction, for a more perfect structural arrangement. On Earth, cadmium zinc telluride is used as a substrate, or base, for growing mercury cadmium telluride crystals, useful for making infrared radiation detectors. The alloying element, zinc, is added to minimize the strain where the two crystals join, thereby reducing defects. Defects caused by gravity driven fluid flows on Earth produce less perfect crystals and thus less perfect end products. This is the sixth semiconductor crystal to be grown on USML-2 in the Crystal Growth Furnace. This afternoon Payload Specialist Al Sacco continued changing parameters in the Geophysical Fluid Flow Cell Experiment to produce a variety of fluid flows which mimic those in planets, atmospheres and stars. Today's experiments continued a series which study the atmospheres of gaseous planets such as Jupiter and Saturn. Scientists hope lessons learned from these studies can apply to fluid flows on Earth. Researchers will use data from this experiment to build better computer models of fluid behavior which could one day aid in forecasting ocean flows and weather patterns. A demonstration used to isolate sensitive experiments from small vibrations and disturbances in the Shuttle was deactivated today. Earlier this week, the Suppression of Transient Acceleration by Levitation Evaluation, or STABLE, was tested with an experiment called "CHUCK," an investigation designed to study materials processes in microgravity that are applicable to crystal growth mechanics. Comparisons of these data will be made post-mission, and should help determine the effectiveness of STABLE for reducing background vibrations. The STABLE experiment was designed and developed by McDonnell Douglas of Huntington Beach, Calif., and NASA's Marshall Space Flight Center. Early in the blue shift, Mission Specialist Cady Coleman began setting up the Drop Physics Module for an experiment run which will involve positioning a drop of water in the center of a silicon oil drop. Precise adjustments to sound waves within the drop chamber may enable Coleman to maneuver the water drop to the oil's center. The ability to deploy and manipulate compound drops is an important step towards uniform encapsulation -- a technique which could aid scientists in using polymer systems to study the encapsulation of living cells aimed at the possible treatment of hormonal disorders such as diabetes. In other Drop Physics Module activity, scientists obtained detailed observations of the water drops and how they are affected by surfactants, or chemicals, that change the surface tension. In today's experiments, different concentrations of the same chemical were added to the drops which Payload Commander Kathryn Thornton then manipulated using sound waves. Principal Investigator Dr. Robert Apfel of Yale University gathered a plethora of data on the oscillations of the drops which were squeezed and then released so their shapes, thanks to microgravity, repeated themselves over a period of time. Surfactants change the properties of a liquid drop, and are of interest to scientists for the role they play in countless industrial processes, from the production of cosmetics, to the dissolution of proteins in synthetic drug production. Another application could be the production of new surfactants with more desirable properties. During the next 12 hours, crew members Coleman and Payload Specialist Fred Leslie will alternate their four-hour breaks, working with the Drop Physics Module, the Oscillatory Thermocapillary Flow Experiment, and the Geophysical Fluid Flow experiment. STS-73 Flight Day 13 Highlights: On Wednesday, November 1, 1995, 8 a.m. CST, STS-73 MCC Status Report #24 reports: Columbia is currently maintaining its "gravity gradient" attitude with the orbiter tail pointing towards the Earth and the port wing pointing in the direction of travel. It will maintain its position, which provides crew members with a stable platform in which to conduct the USML-2 experiments, until a nine-hour thermal conditioning session on Thursday beginning at 2:23 a.m. CST. Because the gravity gradient attitude shades portions of the orbiter, the thermal conditioning periods are needed to warm the underside of the orbiter and subsequently increase the landing gear tire pressure. Following Tuesday's 14-hour thermal conditioning period, the flight control team recorded a 14 psi increase, from 325 psi to 339 psi, in the left landing gear tires. After refining the estimates for the orbiter's weight and center of gravity, flight controllers are now gearing their thermal conditioning plans to provide a minimum pressure of 326 psi in the landing gear tires at the end of the mission. A fourth warm-up session is planned for Friday. On Wednesday, November 1, 1995, 6 a.m. CST, STS-73 Payload Status Report #20 reports: (11/21:07 MET) Successful science operations continue on flight day 12 of the second United States Microgravity Laboratory Spacelab mission. The crew and investigators are interacting effectively, optimizing science return and proving USML-2 to be a superb example of a true interactive science laboratory. "The drop is right in the middle; I tell you the bubble is looking great," observed Mission Specialist Cady Coleman, after successfully centering a water drop within a drop of silicone oil in the Drop Physics Module. This compound drop configuration was achieved while the interfaces of the water and oil drops were moving in opposite directions, a condition known as "slosh mode." According to Drop Physics Module Program Scientist Arvid Croonquist of NASA's Jet Propulsion Laboratory, this is the first time during the mission that this has been accomplished, and Drop Dynamics Experiment Principal Investigator Taylor Wang described the data gathered as "very important" and as having "major significance." The Drop Dynamics Experiment, developed by Vanderbilt University, serves to gather high-quality data on the motions of liquid drops in low-gravity for comparison with theoretical predictions. Data from these studies may help scientists to design novel drug delivery systems for medical treatment. "I've been imagining it for eighteen months," said Coleman regarding the centered drop, "so it's sure nice to see it for real." Geophysical Fluid Flow Cell co-investigator Fred Leslie of NASA's Marshall Space Flight Center monitored the experiment's simulations of Jupiter's inner atmosphere. The GFFC is intended to study how fluids move in microgravity, helping researchers understand the large-scale fluid dynamics of stellar and planetary atmospheres such as Jupiter's. The large-scale motions of these atmospheres are strongly constrained by rotation and gravity. This creates forces that cause thermal circulations, and these atmospheric structures are often surprising and continue to baffle scientists seeking fundamental understanding of such phenomena as Jupiter's zonal bands, especially of the atmospheric layers that cannot be seen from Earth. "We hope this will give us ideas about the hidden inner atmosphere of Jupiter." explained GFFC co-investigator Dan Ohlsen. According to Payload Specialist and co-investigator Fred Leslie, "Much of the emphasis is on the sun and Jupiter, but there are also some areas of applicability to the Earth. We can isolate certain phenomena with the experiment and take out some of the complicating things in terms of climate-- things like rainfall and clouds." Leslie and others on the GFFC science team sometimes characterize the experiment system as enabling studies of "a planet in a test tube." Fred Leslie next turned his attention to the Glovebox facility and the Oscillatory Thermocapillary Flow Experiment, developed by NASA's Lewis Research Center. The purpose of this experiment is to study the conditions under which thermocapillary flows change from steady to oscillatory, or variable. These flows result from surface tension variation along a liquid/gas free surface. In particular, OTFE complements the Surface Tension Driven Convection Experiment by allowing the science team to investigate the effect of changing the shape of the test chamber during the beginning of oscillations or variations. Oscillatory fluid flows are a type of phenomena which can affect Earth-based materials processing and some engineering applications, by causing unwanted flows when materials are cooled from a liquid or a gas form. Therefore, it is very important for scientists to understand these phenomena and be able to predict the conditions under which they occur, as well as their nature and extent. Although these oscillatory, or variable, flows can be studied on Earth under very specific sets of conditions, the effects of thermocapillary flows are hidden by the dominant effects of gravity-driven fluid motions. Knowledge of the behavior of thermocapillary flows is important because of the influence fluid flows have in areas such as fuel management and material processing methods. On Wednesday, November 1, 1995, 5 p.m. CST, STS-73 MCC Status Report #25 reports: Members of the Red Team handed over to their Blue Team counterparts at 2:38 p.m. CST. After a 12-hour workday, the Blue Team will hand over to the Red Team at 2:38 a.m. Thursday. During the afternoon, mission specialists Michael Lopez-Alegria and Cady Coleman participated in an interactive educational event with students in Bozeman, Montana, and Las Cruces, New Mexico. Columbia continues to orbit the Earth at an 170-mile high altitude in a gravity gradient attitude with the orbiter tail pointing towards the Earth and the port wing pointing in the direction of travel. Because the gravity gradient attitude shades portions of the orbiter, thermal conditioning periods are needed to warm the underside of the orbiter and subsequently increase the landing gear tire pressure. Thus far in this mission, Columbia has undergone two warm-up periods and two more are expected. The next session is scheduled for Thursday and will last about nine hours. On Wednesday, November 1, 1995, 6 p.m. CDT, STS-73 Payload Status Report #21 reports: (12/09:07 MET) Today the USML-2 Colloidal Disorder-Order Transition team observed something unusual -- and unexpected -- in one of their colloidal sphere experiment samples. Downlink video indicated uniform crystals throughout the length of a sample team members thought was too densely packed to grow crystals. On Earth, this dense concentration causes the spheres to move so slowly that the crystals only form on a geological time scale (millions of years). The experiment, which is being performed in the Glovebox, studies the fundamental theories that model atomic interactions. One way to learn how atoms interact is by studying groups of simple, larger particles that behave in a similar manner. This experiment, called a colloid, uses microscopic solid plastic spheres suspended in a fluid to model atomic interactions. The Colloidal Disorder-Order Transition experiment shares a fundamental characteristic with atomic systems -- both undergo a transition from a disordered liquid state to an ordered solid state under the proper conditions. An example is water molecules becoming ordered to form ice. Research in this field could lead to improved materials processing on Earth. Payload Specialist Al Sacco sent down the first close-up views of growing zeolite crystals to team members here on the ground this morning. The team saw a uniform population of suspended particles throughout the samples, which was expected. This space-based experiment is unlike an identical mixture which is growing at the Worcester Polytechnic Institute in Worcester, Mass. Gravity on Earth has caused the particles in that experiment to settle. Sacco, who is principal investigator for the zeolite furnace experiment, refined the composition of USML-2 zeolites, which are formed by mixing a silica solution and an alumina solution, in hopes of growing even larger crystals with less, or controlled, defects for post-mission structural analysis. Zeolite crystals are used in the chemical process industry as filters, catalysts, and adsorbents. Investigators for the Geophysical Fluid Flow Cell Experiment today imposed parameters on their experiment which produced more Earth-atmosphere-like flows than on previous runs. The team sent instructions to Payload Commander Kathryn Thornton to do a "terrestrial" run of the experiment, mimicking the large temperature gradient from the Earth's equator to its poles. This produced waves in the experiment fluid flows much like those in our jet stream. The fluid flow cell experiment uses silicone oil between two rotating hemispheres to model flows in oceans and atmospheres of planets and stars. Rotation speed of the hemispheres, fluid temperature, and electrical charges (which simulate gravity) are changed with each run to reflect conditions in the different environments. Information gleaned from investigations such as this could aid in forecasting ocean flows and weather patterns. The small potatoes in the Astroculture plant facility continue to grow and are healthy. Sacco observed the plants' growth today, sending video downlink of the potato leaves which, though wilting, are performing normally. This tells investigators that the potatoes are getting the proper nutrients, light, water, and humidity from the facility, which is being tested on USML-2 as a viable apparatus for growing plants in microgravity. Long-duration space stays may necessitate growing plants to minimize the cost of life support. Plants can help provide food, oxygen, and pure water and can also assist in removing carbon dioxide from human space habitats. The potatoes are being grown to study how starch accumulation in plants is affected by the microgravity environment. The sixth semiconductor crystal to process in the Crystal Growth Furnace continues its growth in a unique apparatus which prevents wall contact, allowing the sample material to form a liquid bridge. The crystal is being grown for comparison to semiconductor crystals grown on USML-1, which indicated the more defect-free areas occurred where the sample material did not touch the wall of the container during growth. The crystal has grown a little over one-and- a-half inches (4 centimeters) and will continue its growth period for about 8 more hours. The crystal will be dissected post-mission to identify the effects of gravity as a factor in causing structural defects in the crystal system. Crystals of cadmium zinc telluride are used for infrared radiation detectors. Drop Physics Module investigators recorded the behavior of an oil drop today, subjecting it to the same vigorous sound waves as those imposed previously on a drop of water. Comparisons between the surface behavior of these two drops, and the behaviors of other drops, will be made post-mission using a library of video recorded during the USML-2 mission. Other experiment runs today, part of Dr. Taylor Wang's investigations on the behavior of liquid drops in low gravity, include manpulating a bubble in a drop of oil and a drop of water with a small amount of surfactant added. With each experiment run, Thornton increased the sound waves, or combined different sound wave intensities to produce a variety of behaviors from these drops. Scientists will use data from these experiments for comparison with theoretical predictions and ground-based studies using very small drops. It will provide scientific and technical inputs for the development of new fields, such as containerless processing of materials and polymer encapsulation of living cells. STS-73 Flight Day 14 Highlights: On Thursday, November 2, 1995, 8 a.m. CST, STS-73 MCC Status Report #26 reports: Columbia, with both payload bay doors fully open, currently is in its third thermal conditioning session designed to warm the underside of the orbiter. It will remain in the "belly to sun" attitude until about 2 p.m. Thursday afternoon. On Thursday, November 2, 1995, 6 a.m. CST, STS-73 Payload Status Report #22 reports: (12/22:07 MET) "Things are going fantastically well, and we're just looking forward to getting as much science in the remaining time as we can," explained USML-2 Alternate Payload Specialist Glynn Holt early this morning in an interview for Mutual NBC Radio as fluid physics and combustion science took center stage on the thirteenth night of the second United States Microgravity Laboratory mission. Spacelab systems and facilities continued to operate well and gather good data. The crew worked with the Fiber Supported Droplet Combustion experiment in the Glovebox, performed the fission experiment in the Drop Physics Module, monitored fluid flows for the Geophysical Fluid Flow Cell experiment, and initiated the last run of the Supression of Transient Acceleration by Levitation Evaluation (STABLE) vibration isolation system. "Fred gets an A+ in combustion theory," exclaimed investigators for the Fiber Supported Droplet Combustion experiment (FSDC), offering Payload Specialist Fred Leslie "a collective high-five" for his "outstanding work" in the Glovebox facility. Leslie had been placing drops of fuel on a thin fiber, using needles in the experiment module, and igniting them with a hot wire. Earlier in the evening, Leslie worked closely with the FSDC science team to successfully troubleshoot difficulties with clogged drop accumulators, and then performed a series of excellent burns, varying the quantities of methanol and methanol/water fuel with each run. Also varied were fiber size and air flow rates. These experiments resulted in some droplet extinction diameters (the size of the drop as it burns out) larger than any initial droplet size capable of being studied on Earth. The science team was very pleased with what they described as the "textbook quality" data received and expressed their appreciation for the crew's hard work and persistence. Leslie showed his enthusiasm for the work when he humorously responded, "I don't get to play with fire much up here. I'm kind of enjoying it." The NASA Lewis Center's FSDC investigation consists of new hardware and is on its first flight. The primary objective for this research is to provide scientists new fundamental insights into the dynamics of droplet burning which will be compared to state of the art analytic and numerical models. "It did fission, and I got some good data," announced Mission Specialist Cady Coleman referring to the initial drop fissioning runs in the Drop Physics Module. Coleman used sound waves to manipulate rotating drops of silicone oil until they split, or underwent fission. Project Scientist Arvid Croonquist and his science team worked with Coleman throughout the night, uplinking instructions and watching downlink video. They were testing one set of theories that describes the breaking apart of distorted, or pre-flattened, drops while varying the viscosity (or thickness) of the fluid. Drop Dynamics Experiment Principal Investigator Taylor Wang and his co-investigators from Vanderbilt University observed and analyzed conditions at which drops of various sizes and viscosities split, and he described Coleman's first run of the procedure as "a very successful drop fission." Also, during this run, the science team was able to get good pictures of the ligament, or thread of fluid, connecting the two halves of the drop as it passed through its critical "saddle" point while splitting in two. On the first USML mission, Wang's team used the Drop Physics Module to confirm a theory that was more than 100 years old. Using fluids ranging from water to oils, the module spun single drops until they formed a dog-bone, or two lobe shape. All the drops changed into the same shape at the same point and at exactly the point that had been predicted over a century ago by fluid dynamics pioneer Lord Raleigh. Results from USML-2 are helping to develop theoretical models for the drop fission process. Troubleshooting continues on the High Data Rate Recorder (HDRR), which began experiencing intermittent data degradation between MET 12/14:30 and 12/14:58. Scientific data is being stored on the Orbiter's recorder during loss of signal periods and downlinked via Hi-Pac TV. The Space Acceleration Measurement System (SAMS) and the Orbital Acceleration Research Experiment (OARE) continued to track accelerations caused by movements and variations within the Shuttle, as well as by Shuttle maneuvers and atmospheric drag. The Principal Investigator Microgravity Services Project team, of NASA's Lewis Research Center, is at the Spacelab Mission Operations Control Center to help scientists evaluate the effects of accelerations on sensitive microgravity experiments. Both instruments make continuous records of accelerations for analysis after the flight. In addition, OARE is providing data on the relatively steady, or low-frequency, accelerations that occur in the Shuttle. This information is being provided to the USML-2 Principal Investigators in real-time throughout the mission. The crew also activated the STABLE instrument, and unattended monitoring continued during the final run of the device. The STABLE system was developed by NASA's Marshall Space Flight Center jointly with McDonnell Douglas to test a device designed to isolate small science experiments from high-frequency accelerations, including Shuttle maneuver operations and crew activity. On Thursday, November 2, 1995, 4 p.m. CST, STS-73 MCC Status Report #27 reports: What flight controllers believe to be an occasional glitch with two of Columbia's small steering jets reoccurred today, resulting in a temporary shutdown of the two small, or vernier, jets located on the tail of the spacecraft. The glitch has occurred twice before during the mission, and has been resolved each time by turning the shuttle's autopilot off and on. The same actions restored the jets function during this afternoon's problem, and they are now functioning normally. The glitch poses no problem for the mission, since Columbia's 38 primary jets are all in good working order. The small vernier jets are only used to minimize interference with sensitive experiments ongoing in the lab module. The four crew members on the Red Team handed over to the Blue Team at 2:38 p.m. CST. The three Blue Team crew members will be on duty till 2:38 a.m. Friday when they hand over to the Red Team. Early in the afternoon Pilot Kent Rominger, and payload specialists Kathryn Thornton and Al Sacco conducted experiments in space and answered questions from students in Worcester, Massachusetts, and Louisville, Kentucky. The experiments and questions focused on surface tension and combustion concepts. Students were involved in ground based adaptation experiments that have enabled them to work alongside their counterparts in space. To demonstrate surface tension in space, Sacco squeezed out a ball of orange juice which immediately formed a sphere. The demonstration was designed to illustrate how surface tension can make a fluid form a sphere when it doesn't have to contend with gravity. Shortly after the demonstration, Sacco drank the experimental orange juice sphere. The surface tension experiment studies the transition between steady fluid flows to unstable fluid flows. Scientists are interested in such studies because of their applications in areas of materials processing such as the production of high-tech crystals, metals, alloys and ceramics. The combustion experiments will give scientists insight into the dynamics of burning fuel. After completing its third thermal conditioning period earlier today, Columbia returned to a "gravity gradient" attitude with the orbiter tail pointing towards the Earth and the port wing pointing in the direction of travel. Because the gravity gradient attitude shades portions of the orbiter, thermal conditioning periods are needed to warm the underside of the orbiter and subsequently increase the landing gear tire pressure. One more warm-up period is expected on Friday morning. On Thursday, November 2, 1995, 6 p.m. CST, STS-73 Payload Status Report #23 reports: (13/10:07 MET) As the past 12 hours unfolded on the second United States Microgravity Laboratory mission, Payload Commander Kathryn Thornton and Payload Specialist Al Sacco spent a good portion of their shift working on experiments in the Glovebox facility. Investigators for the Fiber Supported Droplet Combustion Glovebox experiment saw something this morning they hadn't expected. Hydrocarbon-mix droplets deployed in the facility burned slower and produced more soot than drops of an alcohol-mix. Researchers also learned that larger drops burned longer, as expected. These tests, which study combustion behavior in microgravity, were conducted using various fuel mixtures in different-sized drops and changing air flow rates to see how quickly the drops ignite and extinguish. Throughout the morning, Thornton deployed the drops onto thin fibers, and ignited them by placing an electrical hot wire near the drop. The longest burn, that of a large hydrocarbon-mixed drop, lasted for about 40 seconds. Scientists will analyze their data post-mission to learn more about the chemistry of the combustion process, information which will aid in the development of combustion experiments for the International Space Station. Research in this field could spark a totally new approach in the design of space- based safety equipment, such as fire alarms. It could also aid in cleaner fuel use on Earth. The first crystal growth experiment ever designed to produce a crystal without the growing portion touching its container wall has been completed in the Crystal Growth Furnace. Principal Investigator Dr. David Larson hopes to bring home an almost defect-free cadmium zinc telluride crystal thanks to the unique container apparatus, designed to grow the crystal as a liquid bridge. The two-inch (five centimeter) crystal, which grew for about 30 hours, is the sixth of eight semiconductor crystal growths planned for the versatile, high-temperature furnace. Growing these semiconductors in microgravity is necessary for a more uniform distribution of chemicals in order to obtain crystals with a more perfect structure. Cadmium zinc telluride crystals are used to make infrared detectors. The next sample set for processing in the Crystal Growth Furnace is a crystal of gallium doped germanium. Growing this material, which has well-known properties, provides an engineering test of a new Crystal Growth Furnace capability to mark the boundary between the melted and solidified portions of a crystal at given time intervals. The marks make post-flight analysis of crystal growth more precise. Today's experiment runs of the Particle Dispersion Experiment increased Principal Investigator Dr. John Marshall's data base for future Shuttle and International Space Station aerosol dispersion investigations. Performed in the Glovebox facility, the experiment demonstrates how fine natural particles, such as dust, disperse within an atmosphere, then assemble back together (or reaggregate) into larger clusters. Earlier this week the experiment confirmed a theory that aggregation occurs in all dust clouds. Investigators for the Geophysical Fluid Flow Cell Experiment today set their experiment parameters to create flows mimicking those of the sun's interior. Information from this experiment run will be used to validate data collected earlier in the mission on this same phenomena. Rotation rate, temperature and voltage within the facility are varied to simulate specific atmospheric conditions. The fluid flows that result are relevant to the study of oceans, planetary atmospheres, and stars Ð- information could one day aid in weather forecasting. Protein crystals activated earlier in the mission continue to grow, ensuring investigators that there will be ample data for post-mission analysis. One of these experiments, the Protein Crystallization Apparatus for Microgravity, holds more than six times as many samples as are normally accommodated in the same amount of space. These crystals are being grown using the vapor diffusion method. In vapor diffusion, liquid evaporates from a protein solution and is absorbed by a reservoir solution in a wicking material. As the protein concentration rises, the proteins form crystals. These experiments are a precursor to long-duration crystallization investigations aboard the International Space Station, which would greatly benefit from the ability to control crystal growth times of up to approximately six months in length. Proteins play important roles in daily life, from providing nourishment to fighting disease. When the blue shift comes on duty, Mission Specialist Catherine Coleman and Payload Specialist Fred Leslie will devote the majority of their time to Drop Physics Module and Glovebox experiments. STS-73 Flight Day 15 Highlights: On Friday, November 3, 1995, 8 a.m. CST, STS-73 MCC Status Report #28 reports: The STS-73 crew members told reporters this morning the experiments comprising the United States Microgravity Laboratory-2 payload are pathfinders for the type of work that will be performed regularly on the International Space Station. The comments came as all seven crew members took a break from their work to participate in the traditional in-flight crew news conference. The astronauts answered a variety of questions regarding the USML-2 science, life on orbit and Sunday morning's planned landing at Kennedy Space Center. During the news conference, Payload Commander Kathy Thornton said the information gathered on Shuttle missions will be used to plan the science activities on the Space Station. She also said many of the telescience tools that were used and tested during STS-73 will help make operations on the Space Station run smoothly. Columbia is once again positioned with its belly pointing toward the Sun. The attitude is designed to warm the underside of the orbiter and subsequently increase the landing gear tire pressure. Previous thermal conditioning sessions have maintained tire pressures at or above the target levels for landing. All systems on board Columbia continue to perform well and are ready to support landing operations. On Friday, November 3, 1995, 6 a.m. CST, STS-73 Payload Status Report #24 reports: (13/22:07 MET) "This is kind of a pathfinder for the kind of investigations we'll have on the Space Station," said Payload Commander Kathy Thornton during the crew news briefing early this morning, characterizing the interactive nature of much of the science taking place on this Second United States Microgravity Laboratory mission. "There are very complicated experiments on board, but they're working beautifully," she concluded. "These are large plates, larger than what I have seen; we're talking millimeters," exclaimed Mission Specialist Cady Coleman, announcing an unusual and surprising observation to Colloidal Disorder-Order Transition (CDOT) experiment co- investigator Richard Rogers. Coleman was working in the Glovebox facility measuring the fundamental properties of polymethyl-methacrylate, at the point where it solidified, and describing them to the science team on the ground. The sample Coleman had been working with, essentially a concentration of microscopic plastic spheres suspended in a liquid medium, unexpectedly formed a stable disc-shaped crystal with dendrites, or branches, projecting outward from its edges. "What I see is almost snowflake-like, with dendritic arms," Coleman added, describing a phenomenon that has never been seen on Earth. "This is like having a snowflake remain in a glass of water without melting or dissolving; the dendrites didn't collapse," noted CDOT co- investigator Jixiang Zhu, referring to the phenomenon as "very peculiar, really." Colloids are suspensions of finely divided solids or liquids floating in a gaseous or liquid medium. The CDOT experiment, developed by NASA's Lewis Research Center, uses these colloidal suspensions of solid spheres as models of atomic interactions to test theories that describe these interactions. CDOT is the first of a series of Space Shuttle and Space Station experiments that is helping scientists to determine the validity of these theories. This knowledge could enable them to reduce the trial and error involved in developing new and better materials. According to co-investigator William Meyer, this most recent observation has yielded an "extremely close analogy for atomic behavior" with "profound implications for condensed matter physics," proving that "significant and novel results can be obtained from doing this kind of science in space." Early last night, drop fission experiments in the Drop Physics Module went particularly well. The efficiency of some of the earlier successful runs was enhanced by the fact that some of the drops could be reused because they re- coalesced after dividing. Payload Specialist Fred Leslie had success dividing and merging drops of 1,000 centistoke oil, and was consistently able to rotate the single drops until they broke into two drops. A centistoke is a unit of viscosity or fluid thickness. When he tried working with the much thicker 10,000 centistoke drops, however, they deployed too slowly and tended to adhere to one of the two drop injectors. He then switched to thinner drop injectors, but the oil still proved too difficult to deploy. According to DPM Program Scientist Arvid Croonquist of NASA's Jet Propulsion Laboratory, "that's part of the science, pushing the limits to find the right viscosity levels. We're content with the results." This Drop Dynamics Experiment is intended to gather high-quality data on the dynamics of liquid drops in microgravity for comparison with theoretical predictions. Results from this mission should help develop theoretical models for the drop fission process. "I'm looking forward to spending the next year or so analyzing the data from this experiment," said Fred Leslie, during this morning's news conference, regarding the Geophysical Fluid Flow Cell (GFFC). He and Mission Specialist Michael E. Lopez-Alegria monitored GFFC's fluid flow patterns and film frame rate and reported their findings to investigators in Huntsville, Ala. One solar simulation was completed, and a second has begun. Both these scenarios operate under high-voltage and high-rotation conditions. During the film magazine changeout, the crew adjusted the film camera, hoping to reduce the frame rate going through the camera; however, the camera is still running continuously. While responding to a question about zeolite crystal growth during today's news conference, Payload Specialist Al Sacco described some of ZCG's "outstanding results," adding that, "if we do well with zeolites, we could have some major breakthroughs down the road, pointing us in the right direction for Space Station research." Last night, the crew monitored the ZCG experiment, and unattended crystal growth continues. In the Crystal Growth Furnace (CGF), processing of a gallium- doped germanium sample has begun, the first of two samples to be directionally solidified in a technology demonstration studying the effects of different acceleration environments on crystal growth. During this experiment, the Orbiter is using real-time Orbital Acceleration Research Experiment (OARE) data to make a fine adjustment of the orbital attitude by two degrees to line up the CGF axis with the residual acceleration vector on board. On Friday, November 3, 1995, 5 p.m. CST, STS-73 MCC Status Report #29 reports: As the flight of STS-73 enters its home stretch, Columbia's crew members continued science work in the Spacelab module today and began some early preparations for the trip home. Also, Commander Ken Bowersox and Payload Specialist Al Sacco talked to television and radio reporters from Worcester, Massachusetts. Sacco is a native of Boston and is on the faculty of the Worcester Polytechnic Institute. Bowersox and Sacco answered a variety of questions ranging from whether they were homesick to whether they had experienced space motion sickness. Ground controllers again saw a glitch with some of Columbia's smaller steering jets during the day today. The glitch has occurred repeatedly during the flight and each time has been resolved by turning the small, or vernier, steering jet system off and on. The vernier jets are currently turned off and will be turned on again later tonight. Flight controllers believe they will function normally at that time. The glitch poses no problem for Columbia, since all 38 of the primary steering jets on the spacecraft, the system used for most maneuvers and for entry and landing, are working well. The small vernier jets are only used when requested by scientists since they cause minimal interference with sensitive experiments in the lab module. To prepare for landing, crew members performed a communications systems check through U.S. ground tracking sites today. All of the systems are ready to support Sunday's landing. The crew will perform additional checks over the next several hours in anticipation of a Kennedy Space Center landing at 5:45 a.m. CST Sunday. Members of the Red Team crew handed over to their colleagues on the Blue Team at 2:38 p.m. CST. Blue Team members will be on duty until 1:23 a.m. CST Saturday when they hand over to the Red Team. On Friday, November 3, 1995, 6 p.m. CST, STS-73 Payload Status Report #25 reports: (14/10:07 MET) As the second United States Microgravity Laboratory (USML-2) mission draws to a close, the seven member crew continues to work at a steady pace attempting to glean as much science as possible out of the few remaining hours in the mission. A number of investigations have already been deactivated, and others will be powered-down during the next 12 hours. Meanwhile, scientists on the ground are getting data which will provide them with months of exciting post-mission study. "A picture is worth a thousand words - we'd seen it, now we've done it," exclaimed USML-2 Drop Dynamics Lead Scientist Dr. Taylor Wang, when a polymer membrane formed between two coalesced, or joined, drops in the Drop Physics Module this morning. Payload Specialist Al Sacco deployed two drops of different chemicals, which coalesced to become one drop. The membrane which was formed by the ensuing chemical reaction was an important step in an encapsulation study Wang hopes will lead to living cell encapsulation. Wang and his team will analyze such characteristics as the membrane's surface shape and roughness, pore structure and chemical composition. The Crystal Growth Furnace completed growing a crystal of gallium-doped germanium this afternoon. The crystal grew a little over five inches (128 millimeters) after almost nine hours in the unique high-temperature furnace. The final crystal to process in the facility, a second gallium-doped germanium sample, will begin its growth period tonight. As with the first crystal of this type, an electrical pulse will test a new Crystal Growth Furnace capability to mark the boundary between the melted and solidified portions of a crystal at given time intervals. The marks provide information crucial to post-flight analysis of the crystal growth process. During these Crystal Growth Furnace experiments, the Microgravity Analysis Workstation (MAWS), uses mathematical computer models to compute an analytic solution to the microgravity environment of the growing crystal. "Just as a carpenter uses a "plumb line" to align his work on Earth, MAWS provides the crystal growth scientists with a "plumb line" in space for aligning the direction of crystal growth with the direction of orbiter disturbances," said Mission Manager Paul Gilbert. The MAWS team predicted last night that a slight adjustment to the orbiter attitude - 2 degrees - would provide the best microgravity environment for growing the Crystal Growth Furnace crystal." "It's the first time ever the crew maneuvered the orbiter based on a microgravity prediction," observed lead engineer Larry French. Payload Commander Kathryn Thornton used the Shuttle's camcorder this morning to record the progress of the experiments growing in the Commercial Generic Bioprocessing Apparatus. Tiny brine shrimp, numerous forms of plant growth and a variety of protein crystals are doing well. The apparatus makes it possible for commercial industries to fly experiments in the unique environment of space. Early in the blue shift, Mission Specialist Cady Coleman began terminating sample processing and deactivating the protein crystal growth experiments in the facility. The Geophysical Fluid Flow Cell Experiment continues to make maximum use of the remaining time in the mission before the experiment is deactivated. The experiment has completed more than 150 hours of run time, studying how fluids move in microgravity by modeling 29 different scenarios of fluid flows in oceans, atmospheres, planets and stars. Final runs for the experiment have centered around adjusting experiment parameters of speed, temperature and voltage to mimic fluid flows of Earth's atmosphere. Additional data runs to study the convection which exists in Earth's mantle will conclude the experiment's flight on USML-2. During the next 12 hours, Mission Specialist Cady Coleman and Payload Specialist Fred Leslie will continue to power down experiments. They will also get in some final run time with the Geophysical Fluid Cell Experiment and the Surface Tension Driven Convection Experiment. STS-73 Flight Day 16 Highlights: On Saturday, November 4, 1995, 8 a.m. CST, STS-73 MCC Status Report #30 reports: Columbia and crew turned attention homeward this morning, beginning what is planned as the final full day in orbit for shuttle mission STS-73 with several standard checks of landing equipment, all aiming toward a touchdown in Florida at 5:45 a.m. CST Sunday. Early this morning, Commander Ken Bowersox, Pilot Kent Rominger and Mission Specialist Mike Lopez-Alegria tested Columbia's flight control systems, a standard task the day before entry on each shuttle flight. The checks of the cockpit displays, aerosurfaces and navigational equipment found all of the systems in good shape. However, as one of the three cathode ray tube computer monitors located in the forward cockpit was powered on, the crew noted an intermittent flashing and garbling of the display. The monitor had been powered off for most of the flight as part of a standard excess systems power-down performed to conserve electricity on long missions. Bowersox and Rominger will replace the monitor with a one from the aft flight deck in a two hour procedure this morning. Also today, the crew test-fired Columbia's 38 primary reaction control system steering jets that are used for entry and landing, finding them all in excellent condition. Experiment work is continuing in the United States Microgravity Lab-2, but the crew will begin deactivating the experiments as they are completed. This afternoon, the crew will begin stowing cabin gear for tomorrow's return. A final deactivation of the lab module is planned for late tonight. On Saturday, November 4, 1995, 6 a.m. CST, STS-73 Payload Status Report #26 reports: (14/22:07 MET) The second longest Shuttle flight in history, the second United States Microgravity Laboratory (USML-2) mission is winding down. Operations continued overnight to get in some last-minute science before deactivation of the experiments and the eventual power down of the Spacelab in Columbia's cargo bay. The USML-2 payload will be deactivated at MET 15/12:45 (8:35 p.m. CST); Spacelab deactivation will follow at MET 15/13:45 (9:35 p.m. CST). During the last 12 hours, crew members worked closely with scientists on the ground to accomplish unique interactive science, initiating the last run of the Geophysical Fluid Flow Cell Experiment, deactivating the Containment Tubes in the Glovebox Protein Crystal Growth experiment, and terminating several Group Activation Packs in the Commercial Generic Bioprocessing Apparatus. After conducting a procedure to enhance science return, the crew performed two runs with the Surface Tension-Driven Convection Experiment. At the end of this twelve hour shift, the Drop Physics Module, the Geophysical Fluid Flow Cell, the Advanced Protein Crystallization Facility, the Commercial Generic Bioprocessing Apparatus experiment, the Single-Locker Protein Crystal Growth experiment, and the Commercial Protein Crystal Growth experiment have been deactivated. Payload Specialist Fred Leslie monitored the final run of the Geophysical Fluid Flow Cell (GFFC) experiment, a slow rotation scenario that simulated fluid flows found in Earth's mantle. Crew members initiated the run through the Payload General Support Computer, observed fluid flow patterns in this final experiment, and reported the status to investigators on the ground. Working in the Glovebox, Mission Specialist Kathy Thornton performed the final run of the Particle Dispersion Experiment (PDE). A repeat of a previous experiment run, this experiment completed a set of eight science runs with samples of angular quartz. Thornton agitated the module and injected it with air to study the dispersion and collection of the fine particles it contains. Mission Specialist Cady Coleman set up Protein Crystal Growth (PCG) equipment in the Glovebox facility, deactivating and photographing containment tubes which she then returned to the Commercial Refrigerator/Incubator for storage. After installing a thick, adjustable disc to change the test chamber's proportions in the Surface Tension Driven Convection Experiment (STDCE), the crew performed the final video-recorded experiment runs with three-centimeter sample diameters. Investigators saw the highest-order oscillations to date and are very happy with the results. An inflight maintenance procedure was performed to install a thick displacement disc in the two centimeter module in preparation for the final STDCE run. In the Crystal Growth Furnace's Interface Demarcation Flight Test, the second, and final, gallium-doped germanium sample initiated growth last night, following a three hour soak period. This sample will be unique in that the sample has been exposed to a constantly changing residual gravity vector as a result of a change in vernier thrusters, and because the sample temporarily lost electrical continuity during processing. The exposure to changing residual gravity vectors, rather than the stable vector normally required, could produce some unusual structural variations. It is anticipated that this sample could provide investigators with both unusual results and challenges in sample analysis, and they are looking forward to examining this crystal. The crew monitored the Advanced Protein Crystallization Facility (APCF) and reported the facility status to investigators on the ground. They also cleaned the fan intake screen, and unattended protein crystallization continued until deactivation. During the next twelve hours, the crew will monitor the final runs of the STDCE, and the Crystal Growth Furnace will continue cooling as ground controllers and the crew prepare for final USML-2 Spacelab deactivation. Science highlights for USML-2 mission demonstrated the efficiency of interactive science in the operation of experiment hardware, as science teams at Spacelab Mission Operations Control in Huntsville, sent remote commands to their equipment or worked with scientists in orbit to adjust their experiments on the spot. The Astroculture plant growth facility successfully grew 5 small potatoes from tubers to verify Astroculture as a viable plant growth facility and to study the possibility of growing edible foods in space. Both of these objectives were met. Near the end of the mission, the leaves began to yellow and deteriorate, an expected event that leads investigators to believe the tiny potatoes were pulling photosynthetic energy from the leaves. For the first time a crystal was grown as a liquid bridge to minimize contact with the container wall, thus decreasing the number of defects in the crystal. A total of eight semiconductor crystals were successfully grown in the Crystal Growth Furnace. USML-2 also saw the thinnest crystal growth, and the successful growth of two crystals which could lead to products such as computer chips that are faster and use less power than traditional computer chips. Scientists successfully achieved major steps toward drop encapsulation in the Drop Physics Module, a facility which uses sound waves to levitate and manipulate liquid drops for close study. These data will be studied post-mission for future development of encapsulation methods, which could someday involve encapsulating living cells in biological processing systems. Several more firsts were achieved as compound drops were formed, injecting one drop into another, a step that led to successful coalescence -- two drops being deployed separately and coming together to become one. Another first was the formation of a chemical membrane which formed when two drops were deployed, coalesced and formed one drop. Drop fissioning, one drop being spun until it broke into two, also was achieved on USML-2. Another study which looked at surface-altering chemical influences was successful, providing scientists with a wealth of data on different surface behaviors when water drops with surfactants were oscillated using the sound waves. Improved crude oil recovery, environmental cleanup and synthetic drug production could result from this research. The Geophysical Fluid Flow Cell experiment modeled atmospheres and other planetary attributes during 150 hours of run time on USML-2. Several on-orbit scenarios simulated the atmosphere of the planet Jupiter. These early runs showed dramatic changes in flow types with very small variations in the instrument settings. The experiment studied how fluids move in microgravity by modeling 29 different scenarios of fluid flows in oceans, atmospheres, planets and stars. Some experiment runs seemed to validate predictions in a mathematical model of planetary and solar fluid flows. Scientists saw different heat-driven, or thermocapillary flow patterns when the same conditions were initiated at different rates. Lessons learned on USML-2 may be applied to a better understanding of fluid flows on the Earth. The Particle Dispersion Experiment confirmed a theory about the behavior of dust and particle clouds: that aggregation occurs in all dust clouds, drawn together by static electrical charges. This includes the planetary nebulae which coalesce to form stars, global dust storms on Mars, dust clouds from a meteor impact on Earth (such as the one some believe led to extinction of the dinosaurs), and clouds of dust and ash flung into Earth's atmosphere during volcanic eruptions. USML-2 tested variables like particle size, density of the cloud, and type of material (volcanic material, rounded quartz, angular quartz or copper). All the materials showed a similar propensity to aggregate due to electrostatic attraction. Scientists for the Interface Configuration Experiment, a Glovebox experiment, were able to see definite differences in the way fluids adhered to chamber walls in the experimentÕs various containers, and some of the behavior was different from that predicted by the classic mathematical model. This tells investigators they cannot rely completely on the current theory of how surfaces form in low gravity, finding instead that physical factors which are not included in the purely mathematical theory play a significant role. Insights will aid design of fluid systems for space such as those for fuels. The Colloidal Disorder/Order Experiment team observed a stable disc-shaped crystal with dendrites, or branches, projecting outward from its edges, described as "snowflake- like." This phenomenon, which never had been seen on Earth, was described as being like a snowflake in a glass of water not melting or dissolving. This was among the firsts investigators saw during USML-2. Photos and downlink data revealed growing crystals throughout a sample thought to be too densely packed to grow crystals. On Earth, this dense concentration causes the spheres to move so slowly that the crystals only form on a geological time scale (millions of years). The Glovebox experiment, which used a concentration of microscopic plastic spheres suspended in a liquid medium, studied the fundamental theories that model atomic interactions. More than twenty-five droplets of a variety of fuels were ignited as they were suspended on a ceramic wire tether in the Fiber Supported Droplet Combustion experiment. This experiment, which made its first flight in the Glovebox on USML-2, confirmed theories about how fuels burn in microgravity. The experiments resulted in larger droplet extension diameters (the size of the drop as it burns out) than any initial droplet size capable of being studied on Earth. The burning time was 10 times longer than any other experiment runs. The data from this mission has confirmed scientific predictions about burn rate and the amount of fuel leftover after the fire goes out. This will allow investigators to refine theories, and possibly develop new ones about combustion byproducts such as soot and smog. Practical applications could involve controlling fires, and preventing them in large scale space structures. The Particle Dispersion Experiment confirmed a theory about the behavior of dust and particle clouds and the aggregation that occurs in all dust clouds drawn together by static electrical charges. This includes the planetary nebulae which coalesce to form stars, global dust storms on Mars, dust clouds from a meteor impact on Earth (such as the one some believe led to extinction of the dinosaurs), and clouds of dust and ash flung into Earth's atmosphere during volcanic eruptions. USML-2 tested variables like particle size, density of the cloud, and type of material (volcanic material, rounded quartz, angular quartz or copper). All the materials showed a similar propensity to aggregate due to electrostatic attraction. A record number of Protein Crystal Growth samples, around 1,500 total, were flown on USML-2. In addition to providing higher quality proteins than many grown on Earth for X-ray diffraction analysis, these experiments give insights into how proteins crystallize to improve ground-based experiments. Video downlink provided on numerous protein crystal growth experiments during the mission indicated crystals had formed in those samples which will be analyzed post-mission. Knowledge gained from protein crystal research could lead to custom tailored drugs, made possible by determining protein structures of diseases, then designing drugs to fit these diseases like a key fits a lock. During this flight, the Surface Tension Driven Convection Experiment (STDCE) team gathered an extensive information base on unstable fluid flows caused by variations in surface temperatures. Except in very tiny containers such as capillary tubes, such oscillations as observed on USML-2, the second flight for this experiment, had never been observed before on Earth. Varied conditions such as chamber size and proportions, surface shape (which can't be varied on Earth) and heat location and intensity were applied to the silicone fluid surface. By downlink video, the science team was able to clearly pinpoint when the fluid flows transitioned from stable to oscillatory, or unstable, flows, and they found that when the temperature was increased past the point where oscillations began, the flows became erratic. Forty-nine of 43 planned tests were completed, extra time being gained by science team members who ran the experiment remotely, with minimal setup by the crew. A thorough understanding of fluid physics forms a valuable base for improvements in sophisticated materials processing. The Oscillatory Thermocapillary Flow Experiment successfully pinpointed the transition between steady and unsteady heat-induced fluid flows. The investigation duplicated the Surface Tension Driven Convection Experiment (STDCE) but used containers with different depths to provide additional insight into the fluid-flow phenomenon. Results were consistent with STDCE results on this mission. The experiment team has built an extensive catalogue of data on these subtle fluid motions which can affect materials processing on Earth. During USML-2, Zeolite Crystal Growth team members got the data they hoped for prior to the mission when downlink video indicated a uniform population of suspended particles throughout the samples in which growth was expected. This space-based experiment is unlike an identical mixture which the team started growing on Earth before USML-2. Gravity on Earth has caused the particles in that experiment to settle. The composition of USML-2 zeolites (a combination of silica solution and alumina solution ) were refined before the mission in hopes of growing even larger crystals with less, or controlled, defects for post-mission structural analysis. Zeolite crystals are used in the chemical process industry as filters, catalysts, and adsorbents. Some of the zeolites are the type used to crack crude oil into refined petroleum. Increasing their efficiency could result in cheaper gasoline. Brine shrimp, plants, protein crystals and other investigations took advantage of growing time in the microgravity environment in the Commercial Generic Bioprocessing Apparatus. This unique facility enabled a large, diverse range of commercial investigators, such as pharmaceutical companies, to fly an experiment in the Spacelab. Some of the 200+ experiments tested materials that could be used as replacements for skin, tendons, blood vessels and corneas. The Hi-Pac digital TV demonstration provided 4 times the normal amount of video data for scientist feedback during USML-2. The system collected more than 41,000 gigabits of digital data in its demonstration of video communication techniques which will help pave the way for Space Station. The Suppression of Transient Acceleration by Levitation Evaluation, (STABLE), was the first facility to use electromagnetic levitation to isolate sensitive experiments from disturbances in the Shuttle. An experiment, known as "CHUCK," a small, simple system to study materials processes in microgravity that are applicable to crystal growth mechanics, was tested in the facility. For the first run, the STABLE platform floated free through the action of electromagnets. The platform was locked in place for a repeat run. Comparisons should help determine the effectiveness of STABLE for reducing background vibrations. USML-2 science team members made ongoing adjustments to their experiments based on readings from the Three Dimensional Microgravity Accelerometer (3-DMA) experiment. The 3- DMA measured both the absolute level of microgravity acceleration (the difference between zero acceleration and what is experienced during the mission) and microvibrations which could affect the investigations onboard. The Surface Tension Driven Convection Experiment was one experiment which benefited by the real time data from the accelerometer. Space Acceleration Measurement System (SAMS) and the Orbital Acceleration Research Experiment (OARE), recorded acceleration information throughout the mission. OARE sent data down to scientists real-time; while SAMS recorded information on low-frequency accelerations for post-flight analysis and comparison with other experiments. On Saturday, November 4, 1995, 8:30 p.m. CST, STS-73 MCC Status Report #31 reports: Columbia is in the final hours of it's 18th mission, as the crew continues preparing the vehicle for Sunday's planned landing at the Kennedy Space Center in Florida. Managers have elected to attempt the landing in Florida Sunday and Monday and only call up the California landing site at Edwards Air Force Base for Tuesday, if required. The two landing opportunities Sunday are at 5:45 a.m. and 7:19 a.m. Central with the deorbit ignition firing about an hour prior to each landing time. Much of the afternoon and evening was spent with Mike Lopez-Alegria, Cady Coleman and Fred Leslie packing up the Spacelab and orbiter crew compartment for entry and landing activities that begin with the wakeup of the four remaining astronauts about 11 p.m. Ken Bowersox, Kent Rominger, Kathy Thornton and Al Sacco will assist with landing preparations after wakeup as the seven crew members wind down what will be the second longest Space Shuttle mission to date. A one day extension will put Columbia's STS-73 mission in the number one spot for Shuttle mission duration. The current weather forecast for Sunday's landing attempts shows a chance of low clouds hampering visibility on the first opportunity and excessive crosswinds on the second. Weather conditions improve slightly for Monday and are even better on Tuesday. STS-73 Flight Day 17 Highlights: On Sunday, November 5, 1995, 6 a.m. CST, STS-73 MCC Status Report #32 reports: Space Shuttle Columbia returned to Earth Sunday morning, completing the U.S. Microgravity Laboratory-2 mission, the second longest space shuttle mission to date. Columbia and its seven-member astronaut crew touched down at the Kennedy Space Center runway at 5:45 a.m. CST after nearly 16 days conducting microgravity experiments in space. The astronauts, commander Ken Bowersox, pilot Kent Rominger, mission specialists Kathy Thornton, Cady Coleman, and Mike Lopez-Alegria, and payload specialists Al Sacco and Fred Leslie, are expect to return to Houston's Ellington Field late Sunday afternoon. The crew return ceremony is open to the public. Mission Name: STS-74 (73) Atlantis (15) Pad 39-A (56) 73rd Shuttle Mission 15th Flight OV-104 27th KSC landing 2nd Mir Docking NOTE: Click Here for Countdown Homepage Crew: Kenneth D. Cameron (3), Commander James D. Halsell (2), Pilot Jerry L. Ross (5), Mission Specialist William S. McArthur Jr (2), Mission Specialist Chris A. Hadfield (1), Mission Specialist Milestones: OPF -- 07/07/95 VAB -- 10/03/95 PAD -- 10/12/95 TCDT -- 10/17/95 (Reference KSC Shuttle Status Nov 1995) Payload: S/MM-02-Mir Docking,ICBC-05, IMAX, GLO, DSO, MCSA, SAREX, GAS, GPP, Payload/Mir Download - Trek Experiment Mission Objectives: The STS-74 mission is the second of seven planned Space Shuttle-Mir link-ups between 1995 and 1997, including rendezvous and docking and crew transfers, which will pave the way toward assembly of the international Space Station beginning in November 1997. Major objectives include docking with the Mir space station and delivery of a Russian docking module and 2 solar arrays. This mission marks the first time astronauts from the European Space Agency, Canada, Russia and the U.S will be in space on the same complex at one time -- a prime example of nations that will be represented on the international Space Station. Atlantis will carry the Russian-built Docking Module, which has multi-mission androgynous docking mechanisms at top and bottom. During the flight to Mir, the crew will use the Orbiter's Remote Manipulator System robot arm to hoist the Docking Module from the payload bay and berth its bottom androgynous unit atop Atlantis' Orbiter Docking System. Atlantis will then dock to Kristall using the Docking Module's top androgynous unit. After three days, Atlantis will undock from the Docking Module's bottom androgynous unit and leave the Docking Module permanently docked to Kristall, where it will provide clearance between the Shuttle and Mir's solar arrays during subsequent dockings. Atlantis will deliver water, supplies, and equipment, including two new solar arrays -- one Russian and one jointly-developed -- to upgrade the Mir. It will return to Earth experiment samples, equipment for repair and analysis and products manufactured on the station. Also flying aboard Atlantis is the GPP payload consisting of two experiments -- the GLO-4 experiment and the Photogrammetric Appendage Structural Dynamics Experiment (PASDE). The payload is managed by Goddard Space Flight Center's Special Payloads Division. The GLO-4 will study the Earth's thermosphere, ionosphere and mesosphere energetics and dynamics using broadband spectroscopy. GLO-4 also will study spacecraft interactions with the atmosphere by observing Shuttle and Mir glow, Shuttle engine firings, water dumps and fuel cell purges. Three PASDE cannisters, located throughout the cargo bay, will photogrammetrically record structural response data of the Mir solar arrays during the docked phase of the mission. These data will be analyzed on the ground to verify the use of photogrammetric techniques to characterize the structural dynamics of the array, thus demonstrating that this technology can result in cost and risk reduction for the international Space Station on-orbit structural verification. Atlantis will also carry back to earth the University of California at Berkeley Trek Experiment which has been in orbit onboard Mir for the past four years. Launch: Launch November 12, 1995 at 7:30:43.071 A.M. EST. Launch Window was 10 min 09 sec but Atlantis lifted off at the begining of the window. There were no unscheduled holds. Winds at liftoff were from approximately 289 degrees at 6.7 knots; the ambient temperature was 50 degrees F, the barometric pressure was 30.06in Hg; and the relative humidity was 82%. Transatlantic Abort Landing (TAL) sites were Zaragoza, Spain for primary and Moron, Spain and Ben Guerir, Morocco as alternates. White Room close out completed at 6:18am EST. At 7:12am EST the mission management team was polled and all stations were "go for launch" except SRO. Weather constraint, cloud ceiling below 6000ft for RTLS abort. (Reference KSC Weather History 11/12/1995 0700). Range cleared for launch at 7:20am EST. Main Engines cutoff at 7:39am EST. Launch attempt on November 11, 1995 at 7:56am EST was scrubbed due to poor weather at the Transatlantic Abort (TAL) Site. A scrub due to a TAL site has only occured once before on 1/9/86 for Columbia's launch attempt on mission STS-61C. The mission management team decided to enter a 24 hour scrub turnaround and attempt a launch on 11/12/95. Launch Window was 6 min 57 and the countdown had begun on schedule. The crew was onboard when the scrub was called at the T-minus 5 minute mark at approximately 7:51am EST. On 11/09/95, Pad 39-A was cleared to load the onboard cryogenic tanks with liquid hydrogen and liquid oxygen reactants. Reactant loading has been completed. The reactants will provide electricity for the orbiter and crew while in space and drinking water as a by-product during their 8-day mission. (Reference KSC Shuttle Status 11/09/1995). On 11/07/95, Engineers have determined no additional work is required to verify the readiness for flight of the STS-74 solid rocket boosters in light of extremely small cracks found on hold-down posts attached to other boosters that flew earlier this year. Previous inspections on the boosters at the pad indicate no cracking is present. Mission managers will be fully briefed on the matter at the scheduled management team meeting to be held at KSC on Thursday. (Reference KSC Shuttle Status 11/07/1995). On 9/05/95, Main engine (SSME) installation was completed in OPF Bay 2 and the Russian MIR-2 Docking Module closeout operations were completed in the Operations and Checkout Building. (Reference KSC Shuttle Status 9/05/1995). On 8/25/95, three thrusters on the right hand OMS pod were replaced in the OPF (Reference KSC Shuttle Status 8/25/1995). Orbit: Altitude: 213 nm Inclination: 51.6 degrees Orbits: 128 Duration: 8 days, 4 hours, 31 minutes, 42 seconds Distance: 3.4 million miles Hardware: SRB: BI-076 SRM: 360T051A (left), 360T051B (right) ET : SN-74 MLP : MLP-2 SSME-1: SN-2012 SSME-2: SN-2026 SSME-3: SN-2032 Landing: KSC November 20, 1995 at 12:01:27 pm EST on Runway 33. Deorbit burn was done on orbit 128 at approximately 11:00am EST. Dual sonic booms heard in the KSC Industrial area at 11:58:30am EST. Main Landing Gear touched down at the KSC Shuttle Landing Facility at a Mission Elapsed Time of 8 days 4 hours 20 minutes and 44 seconds (12:01:27 EST). Nose Gear touched down at 8 days 4 hours 30 min 54 seconds (12:01:37 EST) and wheels stopped at an MET of 8 days 4 hours 31 min 42 sec (12:02:24 EST). (Reference KSC Shuttle Status 11/20/1995). Weather was acceptable for landing (Reference KSC Weather History 11/20/1995 1200). A second opportunity existed but wasn't necessary for a KSC landing at 1:37pm EST with a deorbit burn at 12:36p.m. on orbit 129. (Reference KSC Shuttle Status 11/17/1995). Mission Highlights: Due to the furlough of US government workers from 11/14/95 to 11/19/95, mission Status reports during those dates are not currently available. STS-74 Flight Day 1 Highlights: On Sunday, November 12, 1995, 11 a.m. CST, STS-74 MCC Status Report #01 reports: About 43 minutes after launch, a two minute and 13 second engine firing changed the shuttle's path into a 162 nautical mile circular orbit. Once on orbit, the five crew members began configuring Atlantis for on-orbit operations. Atlantis' payload bay doors were opened about 90 minutes into the flight, followed by a "go" for on-orbit operations. STS-74 Commander Ken Cameron and Pilot Jim Halsell, about three hours into the last flight of the year, fired the orbiter's reaction control jets in the first of a series of rendezvous burns that refined Atlantis' path to Mir. Shortly after that jet firing, the first Canadian mission specialist, Chris Hadfield, activated the Russian built docking module and its systems. The docking module is housed in Atlantis' payload bay. Hadfield will use the orbiter's robot arm early Tuesday to mate the docking module with the Atlantis' Orbiter Docking System prior to the orbiter's link-up with Mir early Wednesday. The docking is scheduled for 12:28 a.m. CST Wednesday. On Sunday, November 12, 1995, 5 p.m. CST, STS-74 MCC Status Report #02 reports: Activities for the coming day will focus on preparing to connect the Russian Docking Module to the shuttle airlock and getting Mission Specialists Jerry Ross and Bill McArthur ready for a contingency space walk should anything unexpected happen during Tuesday's move of the docking module. Maneuvers continuing the process of the shuttle rendezvous with Russia's Space Station Mir will resume at 10:11 p.m. CST when Commander Ken Cameron and Pilot Jim Halsell kick off the NC 2 burn. The NC 3 burn will occur at 10:09 a.m. CST Monday. Docking is scheduled for 12:28 a.m. CST Wednesday. Mission Specialist Chris Hadfield will test the robot arm that will lift the module out of its payload bay moorings. With the help of Mission Specialist Bill McArthur, Hadfield also will power up and check the Orbiter Space Vision system that will be used to precisely align the robot arm. Cameron will set up the VHF radio gear that will be used for shuttle/Mir communications during the rendezvous. Ross and McArthur will inspect their space suits and pre-breath pure oxygen for an hour and a half to purge nitrogen bubbles from their bodies and prevent a condition known as "the bends" should a space walk be necessary. The pair is not expected to don the space suits unless a space walk is required. The STS-74 crew also is scheduled to be interviewed by the Canadian news media beginning at 6:31 a.m. CST. STS-74 Flight Day 2 Highlights: On Monday, November 13, 1995, 5 a.m. CST, STS-74 MCC Status Report #03 reports: The five member crew aboard the Space Shuttle Atlantis spent the bulk of its second day in space readying the orbiter and its payloads for Tuesday's mating of the Russian Docking Module to the Orbiter Docking System in advance of Wednesday's docking to Russia's Space Station Mir. Both the module and the docking system are located in Atlantis' payload bay. Mission specialists Jerry Ross and Bill McArthur early Monday inspected the space suits they would don should a space walk become necessary during Tuesday's mating operation or the actual linkup of Atlantis to Mir at 12:28 a.m. Wednesday. Following the space suit inspection, Mission Specialist Chris Hadfield powered up the orbiter's robot arm which he will use Tuesday to move the docking module over to the docking system. All systems affiliated with the robot arm operated as expected and are ready to support Tuesday's activities. Crew members also checked out the Orbiter Space Vision System, a precise alignment system for the robot arm that is being tested on STS-74. The OSVS, which will be used during Tuesday's mating operation, consists of a series of large dots placed on the exterior of the docking module and the docking system. Today's schedule also included the installation and alignment of the centerline camera in the center of the Orbiter Docking System. The camera will assist Commander Ken Cameron in final piloting tasks as Atlantis moves into and docks with Russia's Space Station Mir. Additionally, Atlantis' jets will be fired to further refine the closing rate between the orbiter and Mir. At 5 a.m. CST, Atlantis was about 4,000 statute miles behind Mir, and was closing in to the space station at a rate of about 380 statute miles per orbit. This morning, Cameron, Hadfield and other available crew members answered questions posed by Canadian reporters who are in Montreal and Toronto. Hadfield is a Canadian Space Agency astronaut and the fourth Canadian astronaut to fly on the shuttle. On Monday, November 13, 1995, 6 p.m. CST, STS-74 MCC Status Report #04 reports: With all of the systems that will be used to put the Russian Docking Module in place for a Wednesday link-up with the Mir Space Station checked out and ready to go, the STS-74 crew settled down for 8 hours of sleep Monday afternoon. Atlantis, orbiting flawlessly 238 miles above the Earth, is about 2,000 miles away from Mir and catching up at 135 miles per orbit. Earlier in the day, Commander Ken Cameron, Pilot Jim Halsell and Mission Specialists Chris Hadfield, Jerry Ross and Bill McArthur checked out the docking module, the Orbiter Docking System, the shuttle's robot arm and the Orbiter Space Vision System and found all to be in good working order. Ross and McArthur also inspected the space suits they will don should a space walk become necessary during Tuesday's mating operation or the actual linkup of Atlantis to Mir. After an 8:31 p.m. CST wake-up call, Atlantis' astronauts will begin the process of moving the docking module. At 11:31 p.m., Hadfield will power up the Orbiter Space Visions System. At 11:46 p.m., Hadfield and McArthur will grapple the module with the robot arm. At 12:21 a.m. Tuesday, the pair will remove the module from its payload bay moorings and Cameron and Halsell will prepare the Orbiter Docking System for connection to the docking module. At 12:56 a.m., Hadfield and McArthur will use the robot arm to move the docking module over the Orbiter Docking System, then place the arm in a "limp" mode with the docking module and Orbiter Docking System just four inches apart. Cameron will fire Atlantis' steering jets, forcing the hooks and latches to engage and locking the Russian Docking Module in place. Hadfield and Ross will then test the mated Russian docking module's systems. After a rendezvous burn of the shuttle's steering jets at 2:16 a.m., the crew will continue work to configure the docking module systems for Wednesday's docking with the Russian space station. Another firing of the shuttle's thrusters is scheduled for 10:20 a.m. The astronauts will end their day at 12:31 p.m. Tuesday, beginning a six-hour sleep shift that will synchronize their sleep cycle with that of the Mir 20 cosmonauts. STS-74 Flight Day 3 Highlights: On Tuesday, November 14, 1995, 5 a.m. CST, STS-74 MCC Status Report #05 reports: STS-74 crew members early Tuesday successfully mated a 15-foot, Russian built docking module from the Space Shuttle Atlantis's payload bay to the shuttle's Orbiter Docking System. The mating operation went by the book with no problems reported. Chris Hadfield, a Canadian Space Agency astronaut and STS-74 mission specialist, used the shuttle's robot arm to hoist the docking module out of the aft portion of the payload bay, rotated it to a vertical position, and moved it to within five inches of the Orbiter Docking System. At that point, the shuttle fired its downward steering jets and moved the shuttle toward the docking module. Once the two spacecraft were locked together, the docking ring on the Orbiter Docking System retracted, and a series of hooks and latches were engaged insuring an airtight seal between the two spacecraft. The mating was confirmed at 1:17 a.m. CST with Atlantis was over the eastern portion of Europe on its 30th orbit. Shortly after the capture, Commander Ken Cameron expressed the crew's appreciation for the training that prepared them for the docking module installation. At about 3 a.m. CST, the crew received a go from ground flight controllers to ungrapple the robot arm from the docking module. Shortly after that, crew members raised the orbiter's cabin pressure from 10.2 pounds per square inch to 14.7 psi. The cabin's pressure was lowered in the event that a problem during the mating process neccessitated an emergency spacewalk. Crew members also mounted a centerline camera into the top hatch of the docking module. The camera will provide the primary visual cue for Cameron as he maneuvers Atlantis to its docking with Russia's Space Station Mir early Wednesday. Atlantis is trailing Mir by about 1450 statute miles and is closing at a rate of about 180 statute miles every orbit. A series of rendezvous jet firings will further refine the closing rate, leading up to a docking with Mir at 12:27 a.m. CST Wednesday. The crew is scheduled to begin a shortened sleep period at 12:31 p.m. today and will be awakened at 6:31 p.m. today. Flight controllers are working toward an earlier start to the crew's sleep period to enable the astronauts to get additional rest time in advance of tomorrow's docking. Because of the federal government furlough situation, it is likely that the JSC Newsroom will close about 10 a.m. CST today and reopen when the furlough is lifted. STS-74 Flight Day 9 Highlights: On Monday, November 20, 1995, 5 a.m. CST, STS-74 MCC Status Report #06 reports: Fresh from a successful docking with the Russian Mir Space Station, the Space Shuttle Atlantis and its crew are primed for landing today at Kennedy Space Center in Florida. Commander Ken Cameron, Pilot Jim Halsell and Mission Specialists Chris Hadfield, Jerry Ross and Bill McArthur are conducting the final checks of the shuttle's steering systems this morning and watching Florida weather, which is forecast to be favorable. Today's first landing opportunity begins with a deorbit burn at 9:58 a.m. JSC time and concludes with landing at 11:02 a.m. The second opportunity involves a deorbit burn at 11:33 a.m. and landing at 12:37 p.m. Although weather is expected to be good at Edwards Air Force Base in California, landing support teams have not been activated there. If landing does not occur at KSC today, there are opportunities at both sites Tuesday. Because the astronauts awakened about 12:30 a.m. today and will land around midday, they are expected to remain in Florida overnight. A welcome home ceremony is being planned for 11 a.m. Tuesday at Ellington Field's Hangar 990. Atlantis' return to Earth follows a successful docking with Mir and delivery of the Russian Docking Module that now becomes a permanent docking port for future Phase 1 missions to the space station. The STS-74 crew also participated in a number of joint medical and environmental investigations with the Mir crew -- Commander Yuri Gidzenko, Flight Engineer Sergei Avdeyev and Cosmonaut Researcher Thomas Reiter of Germany. Atlantis delivered water, supplies and equipment--including two new solar arrays--to Mir and is returning with U.S., Russian and ESA experiment equipment and samples. The astronauts of the second shuttle-Mir docking flight also studied the Earth's thermosphere, ionosphere and mesosphere with the GLO-4 experiment, and evaluated Mir's solar array structures remotely through three Photogrammetric Appendage Structural Dynamics Experiment canisters in the payload bay.