SPACE FLIGHT 2007 - The Year in Review

United States Space Activities

Launch activities in the United States in 2007 showed a robust increase from the previous year.  There were 28 NASA, DOD, and commercial launches, out of 29 attempts (2006: 22 of 23 attempts, 2005: 16 of 16, 2004: 19 of 19; 2003: 26 of 27 [loss of Columbia]).

Space shuttle

After the loss of Orbiter Columbia on the first (and only) shuttle mission in 2003 and the return of the space shuttle to the skies in Summer 2005 with the liftoff of STS-114/Discovery, more work was required on redesign of the foam-based insulation on the space shuttle’s external tank, new sensors for detailed damage inspection and a boom to allow astronauts to inspect the vehicle externally during flight in 2006.  After another launch delay early in 2007 due to hail storm damage to the shuttle Atlantis on the launch pad, flights resumed in June to continue ISS construction assembly at a brisk rate.  2007 saw three shuttle flights, bringing the total number of shuttle missions since inception to 120.

STS-117

Atlantis, on its 28th mission, lifted off on June 8 at 7:38pm EDT on Mission ISS-13A, carrying the crew of Commander Rick Sturckow, Pilot Lee Archambault, Mission Specialists Jim Reilly, Patrick Forrester, Steven Swanson, John “Danny” Olivas, and FE Clay Anderson who replaced ISS Expedition 14/15 FE Sunita Williams.  Docking at the station was on 6/10 at 3:36pm, and the station crew increased to ten occupants.  Hatches were open at 5:04pm, and the new crew was welcomed aboard the ISS and given the mandatory safety briefing (5:25pm). 

Atlantis delivered two major truss segments, S3/S4, to the station.  Their installation plus other maintenance, servicing & inspection tasks were accomplished by the crew in four spacewalks (EVAs/Extravehicular Activities) by Reilly, Olivas, Forrester and Swanson, running up the 8th, 9th, 10th and 11th spacewalk in 2007.  Clay Anderson was transferred to the ISS as an official station crewmember of Ex­p. 15 and FE Sunita “Suni” Williams swapped places to join the Atlantis crew.  A difficulty arose during the mission with the Russian computers that provide backup attitude con­trol and orbital altitude adjustments.  Russian specialists worked with U.S. teams, troubleshooting and restoring computer capabilities.  By 6/15, Yurchikhin and Kotov got two of three “lanes” in both computers running after bepassing, with ex­ternal cabling, what appeared to be a faulty power switch, and on 6/18, the Russian partners were able to demonstrate the station’s ability to maintain attitude control, enabling the shuttle’s departure.  

After undocking on 6/19 (10:42am), Atlantis spent some time flying solo, and then landed on 6/22 (3:49 pm EDT) on Runway 22 at Edwards Air Force Base (EAFB) in California, concluding a 13-day, 20-hour, 12-minute flight covering 5.8 million miles. The landing was diverted to California due to marginal weather at Kennedy.  This was the 51st landing for the Space Shuttle Program at EAFB, and Suni Williams became a new record holder for women in space, with 194 days, 18 hours, 58 minutes.

STS-118

Shuttle Endeavour lifted off on August 8 at 6:36pm EDT into an early evening sky before sunset on ISS Mission 13A.1, carrying a crew of seven: Commander Scott Kelly, Pilot Charlie Hobaugh, and Mission Specialists Dave Williams (CSA/Canadian Space Agency), Rick Mastracchio, Tracy Caldwell, Alvin Drew and Teacher-turned-Astronaut Barbara R. Morgan.  The launch returned Endeavour to active service after a three-year hiatus for major modifi­cations. The work, done at KSC, included addition of a “glass cockpit,” a Global Positioning System (GPS) for landing and the Station-to-Shuttle Power Transfer System (SSPTS) which allows the Orbiter to draw power from the space station, enabling an extended stay for the mission,- 14 days in this case.

  The payload comprised the S5 truss, a SPACE­HAB module in the cargo bay and the external stowage platform #3 (ESP-3) with a replacement control moment gyroscope (CMG).  Four EVAs were conducted by Mastracchio, Williams and Exp. 16 FE Clay Anderson to install the S5 truss segment and other outboard equipment.  The spacewalkers also replaced the CMG for a faulty one (CMG-3) on the ISS.

After undocking on 8/19 (7:57am EDT), Endeavour landed on Runway 15 at KSC at 12:32 pm on the first opportunity after deorbit.  It was the 119th shuttle mission, the 20th of Endeavour, and the 65th landing at KSC.

STS-120

Shuttle Discovery launched on October 23 (11:38am EDT) on ISS Mission 10A, the 23rd assembly flight, with the crew of Commander Pamela Melroy, Pilot George Zamka and Mission Specialists Scott Parazynski, Doug Wheelock, Stephanie Wilson, Paolo Nespoli (ESA/Italy), and FE Daniel Tani who replaced Clay Anderson als ISS Flight Engineer for Exp. 16.  Discovery docked on 10/25 at 8:40am EDT, smoothly flown by Pam Melroy & George “Zambo” Zamka.  Melroy and ISS Exp. 16 CDR Peggy Whitson made history in becoming the first female spacecraft commanders to lead shuttle and station missions simultaneously (Whitson also holds the distinction of being the first woman to command a station mission).  At the ISS, the STS-120 crew continued the construction of the station with the installation of the Node-2 mod­ule, named “Harmony”, and the relocation of the P6 truss segment.  There were four EVAs, conducted by Parazynski, Wheelock and Tani.  During the 2nd spacewalk, a 360-degree visual inspection of the station’s starboard solar alpha rotary joint (SARJ) was added, which had shown increased friction for some time.  An extra day was added to the mission between the 4th & 5th spacewalks to provide the crew off-duty time and equip­ment preparation for the 5th EVA.  However, the objective of the 4th spacewalk changed in order to repair a solar array, inadvertently torn during deployment, and the 5th spacewalk was transferred to the station crew to perform after the shuttle’s departure.  During the 4th EVA, astronauts constructed solar array hinge stabilizers using strips of aluminum, a hole punch, a bolt connector and 66 feet of wire.  Work­ing like a cuff link, the wire was fed by Parazynski through a hole on the solar array to repair the tear successfully, allowing the full unfurling of the array and restoring full power generation for the station.

Before the undocking on 11/5 (5:32am EST) crew members transferred 2,020 lbs (916 kg) of equipment and scientific samples to the shuttle, including the metal shavings from the SARJ for engineers to study and try to determine the cause of resistance in the starboard rotary joint.

Discovery landed on 11/7 (1:01pm) on Runway 33 at KSC, returning Clay Anderson after 152 days in space and over 18 EVA hours in 3 spacewalks.  Mission elapsed time for 10A was 15 days, 2 hours, 24 minutes and 2 seconds, covering 6.25 million miles.  It was the 120th shuttle mission, the 34th flight of Discovery, and the 66th landing at KSC.

Advanced transportation systems activities

Constellation Program:   In 2007, NASA began laying the foundation for the future of space exploration.  Construction projects across the agency supported the Constellation Program, which is developing next-generation spacecraft and systems to return astronauts to the moon by 2020.  All major contracts for the Ares I rocket were awarded in 2007.  Hard hats, cranes and bulldozers were the equipment of choice at space facilities across the country.  Construction got under way at the U.S. Army's White Sands Missile Range (WSMR) in Las Cruces, N.M., where NASA will hold the Constellation Program's first flight tests in 2008.  At KSC in Florida workers erected a new lightning protection system at the Constellation launch pad, 39-B.  A new test stand for rocket engines is being built at NASA's Stennis Space Center (SSC) in Mississippi.  In July, NASA signed a $1.2 billion sole-source contract with Pratt & Whitney Rocketdyne for the development of the J-2X engines that will power the upper stage of the Ares I crew launch vehicle and Ares V, its heavy-lift follow-on.  In July, Boeing Space Exploration of Houston won a $515 million contract to produce the upper stage of the Ares 1, and in December Boeing also landed the $800 million contract for building and outfitting the avionics ring that will control the Ares I in flight.  The  Orion Crew Exploration Cehicle, which sits atop Ares I, is being built by Lockheed Martin Space Systems of Denver, put under contract in August 2006.

Global Exploration Strategy (GES):   In May, fourteen space agencies interested in working together on space exploration, met in Italy at the 11th Century Abbey of Spineto near Sarteano (Siena), and signed the Global Exploration Strategy, to determine, on a voluntary basis for each member, how NASA’s Vision for Space Exploration, mandated by President George W. Bush in January 2004, Europe’s Aurora program, and similar initiatives in Russia, China, India, Japan and elsewhere can be melded into a cohesive global effort.  The resulting document, "The Global Exploration Strategy: The Framework for Coordination," (see link, below) reflects a shared vision of space exploration focused on solar system destinations where humans may someday live and work.  It represents an important step in an evolving process toward a comprehensive global approach. The framework also allows individual nations to share their strategies and efforts so all can achieve their exploration goals more effectively.

Commercial Orbital Transportation Services (COTS):   Through five new Space Act agreements, NASA signed unfunded agreements with SpaceDev, SPACEHAB, Transformational Space, PlanetSpace, and Constellation International, which indicated interest in developing orbital cargo transportation capabilities.  Two funded agreements were furthermore signed with SpaceX (Space Exploration Technologies) and Rocketplane Kistler (RPK) for demonstrations under the COTS competition.  As part of the COTS demos, SpaceX successfully completed the Critical Design Review (CDR) for its first Falcon 9/Dragon mission.

Space sciences and astronomy

In 2007, the U.S. launched eight civil science spacecraft (one less than in the previous year):  THEMIS 1, THEMIS 2, THEMIS 3, THEMIS 4, THEMIS 5, AIM, Phoenix, and Dawn.

AIM

The AIM (Aeronomy of Ice in the Mesosphere) satellite mission was launched on April 25 from Vandenberg Air Force Base (VAFB), Calif., on a Pegasus-XL launch vehicle to its orbit 600 km (373 miles) above Earth.  AIM is the first satellite mission dedicated to the study of noctilucent or “night-shining” clouds (NLCs) also called Polar Mesospheric clouds (PMCs).  Since its launch, it has provided the first global-scale view of the clouds over the entire 2007 Northern Hemisphere season with an unprecedented resolution of 5 km by 5 km and is nearing completion of observations in the Southern Hemisphere season.  Despite a significant increase in PMC research in recent years, relatively little is known about the basic physics of these clouds at ”the edge of space” and why they are changing.  They have increased in brightness over time, are being seen more often and appear to be occurring at lower latitudes than ever before.  The overall goal of the baseline mission is to determine why PMCs form and why they change.  Since the launch of AIM, significant progress has been made in achieving this goal and that progress continues at a rapid rate.  The AIM data are of very high quality and have changed our view of PMCs and their environment after only one northern hemisphere (NH) season of observations.  AIM is expected to last two or more years during which time the instruments will monitor noctilucent clouds to better understand their variability and possible connection to climate change.

Dawn

After lifting off on a Delta-2 launch vehicle at Cape Canaveral Air Force Station in Florida on September 27 at 7:34am EDT, NASA’s Dawn spacecraft began a 4.8-billion-kilometer (3-billion-mile) odyssey deep in to the Asteroid Belt, including exploration of asteroid Vesta in 2011 and the dwarf planet Ceres in 2015.  These two icons of the Asteroid Belt have been witness to much of our solar system's history.  By using Dawn's instruments to study both asteroids, scientists can compare and contrast the two more accurately.  Dawn's science instrument suite will measure elemental and mineral composition, shape, surface topography, and tectonic history, and will also seek water-bearing minerals. In addition, the Dawn spacecraft and how it orbits Vesta and Ceres will be used to measure the celestial bodies' masses and gravity fields.  The spacecraft's engines use a unique, hyper-efficient system called ion propulsion, which uses electricity to ionize Xenon gas to generate thrust. The three 30-centimeter-wide (12-inch) ion thrusters provide less power than conventional engines but can maintain thrust for months at a time.  Each unit is movable in two axes to allow for migration of the spacecraft's center of mass during the mission.  This also allows the attitude control system to use the ion thrusters to help control spacecraft attitude.   With three units, of which only one thruster is operating at any given time, the ion propulsion system has enough thruster lifetime to complete the mission and still has adequate reserve.  Dawn uses ion propulsion for years at a time, with interruptions of only a few hours each week to turn to point its antenna to Earth.  Total thrust time through the mission will be about 2,100 days, considerably in excess of Deep Space 1's 678 days of ion propulsion operation. 

The thrusters work by using an electrical charge to accelerate ions from Xenon fuel to a speed 10 times that of chemical engines. The electrical level and Xenon fuel feed can be adjusted to throttle each engine up or down.  The engines are thrifty with fuel, using only about 3.25 milligrams of Xenon per second (about 10 ounces over 24 hours) at maximum thrust. The Dawn spacecraft carries 425 kilograms (937 pounds) of Xenon propellant.  At maximum thrust, each engine produces a total of 91 millinewtons -- about the amount of force involved in holding a single piece of notebook paper in your hand.  At maximum throttle, it would take Dawn's system four days to accelerate from 0 to 60 miles per hour.   As slight as that might seem, over the course of the mission the total change in velocity from ion propulsion will be comparable to the push provided by the Delta-2 rocket that carried it into space - all nine solid-fuel boosters, plus the Delta's first, second and third stages. This is because the ion propulsion system will operate for thousands of days, instead of the minutes during which the Delta performs.

New Horizons

Humankind’s first mission to distant planet Pluto was launched by NASA on January 19, 2006, aboard an Atlas V rocket at 2 pm EST.  Its flyby of Jupiter was a special highlight of 2007.   New Horizons passed Jupiter on Febrary 28, riding the planet’s gravity to boost its speed and shave three years off its trip to Pluto.  The 1,054-lbs (478 kg), piano-sized space probe was the eighth spacecraft to visit Jupiter – but a combination of trajectory, timing and technology allowed it to explore details no probe had seen before, such as lightning near the planet’s poles, the life cycle of fresh ammonia clouds, boulder-size clumps speeding through the planet’s faint rings, the structure inside volcanic eruptions on its moon Io, and the path of charged particles traversing the previously unexplored length of the planet’s long magnetic tail.  From January through June, New Horizons’ seven science instruments made more than 700 separate observations of the Jovian system – twice the activity planned at Pluto – with most of them coming in the eight days around closest approach to Jupiter.  In October, the  New Horizons spacecraft found hints that Jupiter's tiniest moons have been obliterated.   The Long Range Reconnaissance Imager (LORRI) camera on New Horizons should have been able to spot moons down to a diameter of about 1 kilometer.  But it saw nothing smaller than Adrastea, a 16-kilometer-wide resident of Jupiter's faint ring system.

STEREO-A  &  STEREO-B

STEREO (Solar TErrestrial RElations Observatory) is the third mission in NASA's Solar Terrestrial Probes program (STP).  The twin STEREO spacecraft were launched on October 25 on a Delta-2 7925-10L rocket from CCAFS (Cape Canaveral Air Force Station) in Florida.  The two-year mission of the two nearly identical space-based observatories, one ahead of Earth in its orbit around the sun (STEREO-A, for “ahead”), the other trailing behind (STEREO-B, “behind”) on April 23 provided the first-ever 3D images and stereoscopic measurements of the Sun, to study the nature of its coronal mass ejections, or CMEs, violent eruptions of matter from the Sun that can disrupt satellites and power grids.  By revealing the CMEs’ 3D structure, the STEREO satellite pair is a key addition to the fleet of space weather satellites, providing more accurate alerts for the arrival time of Earth-directed solar ejections with its unique side-viewing perspective.  The two solar-powered observatories with 3-axis-stabilization, each with a launch mass of  1,364 lbs (620 kilograms, including propellant), were developed by the Johns Hopkins University Applied Physics Laboratory (APL) and communicate with its Mission Operations Center via NASA’s Deep Space Network.

Gravity Probe-B

Gravity Probe-B (GP-B) was a NASA mission to test two predictions of Albert Einstein's theory of General Relativity (GR) using four spherical gyroscopes and a telescope, housed in a satellite orbiting 642 km (400 mi) above the Earth, measuring in a new way and with unprecedented accuracy two extraordinary effects predicted by the General Theory of Relativity (the second having never before been directly measured):  (a) The geodetic effect - the amount by which the Earth warps the local spacetime in which it resides, (b) the frame-dragging effect - the amount by which the rotating Earth drags its local spacetime around with it.  The 6800-lbs (3100-kg) spacecraft was launched on April 20, 2004, on a Delta-2 rocket.  In 2005, almost 90 years after Albert Einstein first postulated his GR and after GP-B orbited Earth for more than 17 months, scientists finished collecting data.  Fifty weeks worth of more than a terabyte of science data were downloaded from the spacecraft and relayed to a comprehensive computer database in the Mission Operations Center at Stanford University, Stanford, Calif., where scientists began the painstaking task of data analysis and validation of the measurements collected from the gyros, telescope, and SQUID (Superconducting Quantum Interference Device) magnetometer readouts, until the liquid helium in the Dewar was exhausted on September 25, 2005.    By end-2007, data analysis was still underway, and an agreement was reached with NASA to extend the data analysis phase through September 2008 and probably beyond.

MESSENGER

NASA's MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging), launched on August 3, 2004, aboard a Delta-2 rocket from Cape Canaveral Air Force Station, Florida, is scheduled to become the first spacecraft to orbit the planet Mercury, beginning in 2011.  The approximately 1.2-ton (1,100-kilogram) spacecraft is in a solar orbit, a 4.9-billion mile (7.9-billion kilometer) journey that includes 15 trips around the sun.  On August 2, 2005, MESSENGER returned to Earth for a gravity boost.  Next, it flew past Venus in October 2006 and did so again on June 5, 2007.  The second close pass of Venus changed the spacecraft's direction around the sun and decelerated it from 22.7 to 17.3 miles per second, placing MESSENGER on target for a flyby of Mercury in January 2008 for a critical gravity assist needed to keep the spacecraft on track for its March 2011 orbit insertion, to begin an unprecedented yearlong study of Mercury. 

MESSENGER will be the first probe to visit the innermost planet in almost 33 years.   During its first Venus flyby, no scientific observations were made since Venus was at superior conjunction, placing it on the opposite side of the sun from Earth, which resulted in a two-week radio contact blackout between the spacecraft and its operators.  The second encounter offered opportunities for new observations of Venus's atmosphere, cloud structure, and space environment.  The spacecraft trained most of its instruments on Venus during the upcoming encounter.  A total of three Mercury flybys, each followed about two months later by a course correction maneuver, will put the spacecraft in position to enter Mercury orbit in March 2011.  During the flybys - set for January 2008, October 2008 and September 2009 – MESSENGER, the second spacecraft sent to Mercury after Mariner 10 flew past it three times in 1974-75 and gathered detailed data on less than half the surface, will map nearly the entire planet in color, image most of the areas unseen by Mariner 10 in 1974-75, and measure the composition of the surface, atmosphere and magnetosphere.

Swift

NASA's Swift satellite, launched on November 20, 2004 aboard a Delta-2 rocket from Cape Canaveral, was designed and built with international participation (England, Italy) to solve the 35-year-old mystery of the origin of gamma-ray bursts (GRBs).  These flashes are brighter than a billion suns, yet last only a few milliseconds.  They had been too fast for earlier instruments to catch.  Scientists now believe the bursts, distant yet fleeting explosions, are related to the formation of black holes throughout the universe: the “birth cries” of black holes. 
The year 2007 has been a roller coaster ride for the Swift mission.  In January, the Swift team received the Bruno Rossi Prize of the American Astronomical Society.  The low point occurred in August & September when Swift was largely off-line due to hardware/software problems on the spacecraft: one of the 3 dual-gyro modules on the spacecraft exhibited anomalous behavior (occasional glitches inits readings), requiring a switch to the backup unit.  After two months of hard work, normal operations were reestablished by end-2007.   Swift has become a key tool not only in studies of GRBs, but also in studying galaxies, quasars, supernova, novae, black holes and neutron stars in our Galaxy, along with active stars, and even comets.  Primary focus contin ues on GRB research, but about half the time is being spread among the other science areas.  To track the mysterious GRBs, Swift carries a suite of three main instruments: the Burst Alert Telescope (BAT), the X-Ray Telescope (XRT) and the UltraViolet/Optical Telescope (UVOT).  Updated orbital lifetime predictions for Swift indicate that the observatory may
remain in orbit up to 2022.

GALEX

The Galaxy Evolution Explorer (GALEX), launched by NASA on April 28, 2003, on a Pegasus XL rocket from a L-1011 aircraft into a nearly circular Earth orbit, is an orbiting space telescope for observing tens of millions of star-forming galaxies in ultraviolet (UV) light across 10 billion years of cosmic history, 80 percent of the way back to the Big Bang.  Its telescope has a basic design similar to the Hubble Space Telescope (HST), but while HST views the sky in exquisite detail in a narrow field of view - like a grain of sand held at arm's length - GALEX  is tailored to view hundreds of galaxies in each observation.  Thus, it requires a large field of view, rather than high resolution, in order to efficiently perform the mission's surveys. 

In 2007, at end-April, GALEX celebrated its fourth year in space with some of the "hottest" stars of the M81 spiral galaxy.  Ultraviolet (UV) images included "sizzling young starlets" of the galaxy as wisps of bluish-white swirling around a central golden glow, representing a "senior citizen" population of smoldering stars.  A neighboring galaxy of M-81, called Holmberg IX, of large fluffy bluish-white material, is practically invisible to the naked human eye but is illuminated brilliantly in GALEX 's wide UV eyes. Its UV colors show that it is actively forming young stars.  Also in 2007, GALEX spotted an amazingly long comet-like tail behind a star streaking through space at supersonic speeds.  The star, named Mira after the Latin word for "wonderful," has been a favorite of astronomers for about 400 years.  It is a fast-moving, older star called a red giant that sheds massive amounts of surface material.  The spacecraft scanned the popular star during its ongoing survey of the entire sky in UV light.  Astronomers then noticed what looked like a comet with a gargantuan tail.  In fact, material blowing off Mira is forming a wake 13 light-years long, or about 20,000 times the average distance of Pluto from the sun.  Nothing like this has ever been seen before around a star.  These images are among thousands gathered meanwhile by GALEX.

Spitzer Space Telescope (SST)

Formerly known as SIRTF (Space Infrared Telescope Facility) and launched on August 24, 2003, the Spitzer Space Telescope is the fourth and final element in NASA's family of Great Observatories and represents an important scientific and technical bridge to NASA's Astronomical Search for Origins program.  The Observatory carries an 85-cm cryogenic telescope and three cryogenically cooled science instruments capable of performing imaging and spectroscopy in the 3.6 to 160 micron range.  Its supply of liquid helium for radiative-cryogenic cooling was estimated post-launch to last for about 5.8 years, assuming optimized operation. 

During 2007, the most astonishing discoveries of SST include final definitive evidence that the universe's first dust -- the celestial stuff that seeded future generations of stars and planets -- was forged in the explosions of massive stars.  These are the most significant clue yet in the longstanding mystery of where the dust in our very young universe came from.  Scientists had suspected that exploding stars, or supernovae, were the primary source, but nobody had been able to demonstrate that they can create copious amounts of dust -- until now.  Spitzer's sensitive infrared (IR) detectors have found 10,000 Earth masses worth of dust in the blown-out remains of the well-known supernova remnant Cassiopeia A.   In another discovery, astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away.  The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there were hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance.   The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores.   A third stunning IR image from Spitzer in 2007 were The Seven Sisters, also known as the Pleiades, seemingly floating on a bed of feathers made from clouds of dust sweeping around the stars, swaddling them in a cushiony veil.  The Pleiades, located more than 400 light-years away in the Taurus constellation, are the subject of many legends and writings.  Greek mythology holds that the flock of stars was transformed into celestial doves by Zeus to save them from a pursuant Orion.  The star cluster was born when dinosaurs still roamed the Earth, about 100 million years ago.  It is significantly younger than our 5-billion-year-old sun. The brightest members of the cluster, also the highest-mass stars, are known in Greek mythology as two parents, Atlas and Pleione, and their seven daughters, Alcyone, Electra, Maia, Merope, Taygeta, Celaeno, and Asterope. There are thousands of additional lower-mass members, including many stars like our sun.  Some scientists believe that our sun grew up in a crowded region like the Pleiades, before migrating to its present, more isolated home.

RHESSI

RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager, in honor of the late NASA scientist who pioneered the fields of solar-flare physics, gamma-ray astronomy and cosmic ray research), launched on February 5, 2002, in 2007continued its operation in Earth orbit, providing advanced images and spectra to explore the basic physics of particle acceleration and explosive energy release in solar flares.  Since its launch the spacecraft has been very successful observing solar flares, which are capable of releasing as much energy as a billion one-megaton nuclear bombs.

Hubble Space Telescope

Seventeen years after it was placed in orbit, the Hubble Space Telescope (HST) continued to probe far beyond the Solar System, producing imagery and data useful across a range of astronomical disciplines to expand our knowledge of the universe.  The orbiting telescope has become one of the most important instruments in the history of astronomy.  Hubble was and is making discoveries at a rate that is unprecedented for a single observatory, and its contributions to astronomy and cosmology are wide-ranging. 

In 2007, the telescope saw a powerful jet from a supermassive black hole blasting a nearby galaxy, a never-before witnessed galactic violence that may have a profound effect on planets in the jet's path and trigger a burst of star formation in its destructive wake.  Known as 3C 321, the system contains two galaxies in orbit around each other.  Data from NASA's Chandra X-ray Observatory show both galaxies contain supermassive black holes at their centers, but the larger galaxy has a jet emanating from the vicinity of its black hole.  The smaller galaxy apparently has swung into the path of this jet.  This "death star galaxy" was discovered through the combined efforts of both space and ground-based telescopes, including Hubble.   Also in 2007, HST provided strong evidence that white dwarfs, the burned-out relics of stars, are given a "kick" when they form.  The sharp vision of Hubble's Advanced Camera for Surveys uncovered the speedy white dwarfs in the ancient globular star cluster NGC 6397, a dense swarm of hundreds of thousands of stars.  Before the stars burned out as white dwarfs, they were among the most massive stars in NGC 6397.  Because massive stars are thought to gather at a globular cluster's core, astronomers assumed that most newly minted white dwarfs dwelled near the center.  HST, however, found young white dwarfs residing at the edge of NGC 6397, which is about 11.5 billion years old.  Astronomers using the HST have discovered a ghostly ring of dark matter in the galaxy cluster Cl 0024+17 that formed long ago during a titanic collision between two massive galaxy clusters.  The ring's discovery is among the strongest evidence yet that dark matter exists.  The existence of an invisible substance as the source of additional gravity that holds together galaxy clusters has long been suspected.  Such clusters would fly apart if they relied only on the gravity from their visible stars.  Although astronomers don't know what dark matter is made of, they hypothesize that it is a type of elementary particle that pervades the universe.  Closer to home, Hubble discovered that massive Jupiter is undergoing dramatic atmospheric changes that have never been seen before: Jupiter's turbulent clouds are always changing as they encounter atmospheric disturbances while sweeping around the planet at hundreds of miles per hour.  But the new Hubble images revealed a rapid transformation in the shape and color of Jupiter's clouds near the equator, marking the entire face of the globe.  Also in 2007, Space Telescope Science Institute (STSI) in Baltimore, the science operations center for Hubble, entered a partnership with Google, to produce “Sky in Google Earth”, a new feature of the newest version of Google Earth, available free of charge.

Preparations have begun for a space shuttle mission to the HST in October 2008, the fourth Hubble Service Mission, for some necessary maintenance and repair work by spacewalking astronauts.

Chandra Observatory

Launched on shuttle mission STS-93 on July 23, 1999, the massive (12,930 lbs/5,870 kg) Chandra X-ray Observatory uses a high-resolution camera, high-resolution mirrors and a charge-coupled detector (CCD) imaging spectrometer to observe X-rays of some of the most violent phenomena in the universe which cannot be seen by the Hubble's visual-range telescope.  Throughout its eighth year of operation, Chandra continued to provide scientists with views of the high-energy universe never seen before which potentially revolutionize astronomical and cosmological concepts. 

After NASA formally extended the operational mission of Chandra from five years to 10 years in September 2001 (including the science grants that fund astronomers to analyze their data and publish their results), in 2007 Chandra astronomers discovered one of the fastest moving stars ever seen, a “cosmic cannonball” that is challenging theories to explain its blistering speed.  Astronomers used Chandra to observe a neutron star, known as RX J0822-4300, over a period of about five years.  During that span, three Chandra observations clearly show the neutron star moving away from the center of the Puppis A supernova remnant, a stellar debris field created during the same explosion in which the neutron star was created about 3700 years ago.  By combining how far it has moved across the sky with its distance from Earth, astronomers determined the neutron star is moving at over 3 million miles per hour. At this rate, RX J0822-4300 is destined to escape from the Milky Way after millions of years, even though it has only traveled about 20 light years so far.

The Chandra X-ray Observatory in 2007 also located an exceptionally massive black hole in orbit around a huge companion star, with intriguing implications for the evolution and ultimate fate of massive stars.  The black hole is part of a binary system in M33, a nearby galaxy about 3 million light years from Earth.  By combining data from Chandra and the Gemini telescope on Mauna Kea, Hawaii, the mass of the black hole, known as M33 X-7, was determined to be 15.7 times that of the Sun.  This makes M33 X-7 the most massive stellar black hole known.  A stellar black hole is formed from the collapse of the core of a massive star at the end of its life.  M33 X-7 orbits a companion star that eclipses the black hole every three and a half days.  The companion star also has an unusually large mass, 70 times that of the Sun.  This makes it the most massive companion star in a binary system containing a black hole.  Chandra may also have cracked a 45-year mystery surrounding two ghostly spiral arms in the galaxy M106 (also known as NGC 4258), a stately spiral galaxy 23.5 million light-years away in the constellation Canes Venatici.  In visible-light images, two prominent arms emanating from the bright nucleus and spiraling outward, are dominated by young, bright stars, which light up the gas within the arms.  However, in radio and X-ray images, two additional spiral arms dominate the picture, appearing as ghostly apparitions between the main arms.  Data from Chandra and other instruments have now confirmed that these so-called "anomalous arms" consist mostly of gas that is being violently heated by shock waves.

Cassini/Huygens

NASA’s six-ton (5.4-metric-ton) spacecraft Cassini continued its epic 6.7-year, 3.2-billion-km journey inside the planetary system of Saturn.  On October 15, 2007, the Cassini spacecraft, in excellent health, had its Diamond Anniversary: it was ten years ago that it departed planet Earth from Cape Canaveral, Florida, and embarked on a seven-year long, circuitous journey of several billion miles across the solar system to the planet Saturn. 

In 2007, the spacecraft continued to return stunning imagery from its continuing journey through the Saturnian system.  Among else, Cassini discovered a narrow belt harboring moonlets as large as football stadiums in Saturn's outermost ring, probably remains of a larger moon shattered by a wayward asteroid or comet eons ago.  Images taken by a camera onboard the spacecraft revealed a series of eight propeller-shaped "wakes" in a thin belt of the outermost "A" ring, indicating the presence of corresponding moonlets.   On September 10, Cassini flew by Saturn's two-toned moon Iapetus and returned pictures which revealed the moon's Yin and Yang nature: a white hemisphere resembling snow, and the other as black as tar.  The images showed a surface that is heavily cratered, along with the mountain ridge that runs along the moon's equator.  Many of the close-up observations focused on studying the strange 20-kilometer high (12 mile) mountain ridge that gives the moon a walnut-shaped appearance.   On the moon Enceladus, Cassini observed jets of fine, icy particles spraying from the moon that originate from the hottest spots on the moon's "tiger stripe" fractures that straddle the moon's south polar region.  Researchers found that all of the jets appear to come from the four prominent tiger stripe fractures in the moon's active south polar region and, in almost every case, in the hottest areas detected by Cassini's composite and IR spectrometer.  In yet another stunning imagery of its radar instrument, the spacecraft found evidence for seas, likely filled with liquid methane or ethane, in the high northern latitudes of Saturn's moon Titan.  One such feature is larger than any of the Great Lakes of North America and is about the same size as several seas on Earth.  The radar imaged several very dark features near Titan's north pole, much larger than similar features seen before on Titan.  The largest dark feature measures at least 100,000 square kilometers (39,000 square miles), but since the radar has caught only a portion of each of these features, only their minimum size is known.  While there is no definitive proof yet that these seas contain liquid, their shape, their dark appearance in radar that indicate smoothness, and their other properties point to the presence of liquids.  The liquids are probably a combination of methane and ethane, given the conditions on Titan and the abundance of methane and ethane gases and clouds in Titan's atmosphere.  Titan is the second largest moon in the solar system and is about 50 percent larger than Earth's moon.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.  The spacecraft successfully entered orbit around Saturn on June 30, 2004.  On December 25, 2004, ESA’s Huygens probe detached from the Cassini orbiter to begin a three-week journey to Saturn’s moon Titan.  After 20 days and 4 million km cruise, the probe safely landed on Titan on January 14, 2005, becoming the first human-made object to explore on-site the unique environment of this moon, whose chemistry is assumed to be very similar to that of early Earth before life formed.

WMAP

NASA's Wilkinson Microwave Anisotropy Probe (formerly called the Microwave Anisotropy Mission, MAP), launched on June 30, 2001, on a Delta-2, is now located in an orbit around the second Lagrange libration point L2.  Its differential radiometers measure, with unprecedented accuracy, the temperature fluctuations of the cosmic microwave background radiation (CMBR).  The CMBR is the light left over from the Big Bang, bathing the whole Universe in this afterglow light.  It is the oldest light in the Universe, having traveled across the cosmos for 14 billion years, and the patterns in this light across the sky encode a wealth of details about the history, shape, content, and ultimate fate of the Universe. 

Since its launch, WMAP has refined our understanding of the universe and its development. It’s observations are a treasure trove of information, including at least three major findings: (1) New evidence that a sea of cosmic neutrinos permeates the universe, (2) clear evidence that the first stars took more than a half-billion years to create a cosmic fog, and (3) tight new constraints on the burst of expansion in the universe's first trillionth of a second.  WMAP measures a remnant of the early universe - its oldest light. The conditions of the early times are imprinted on this light.  It is the result of what happened earlier, and a backlight for the later development of the universe. This light lost energy as the universe expanded over 13.7 billion years and is now seen by WMAP in mivcrowave frequencies.  By making accurate measurements of microwave patterns, WMAP has answered many longstanding questions about age, composition and development of the universe.  It is awash in a sea of cosmic neutrinos, almost weightless sub-atomic particles which move around at nearly the speed of light, passing through us by the millions every second.   WMAP has found evidence for this so-called "cosmic neutrino background" from the early universe.  Neutrinos made up a much larger part of the early universe than they do today.  Microwave light seen by WMAP from when the universe was only 380,000 years old, shows that, at the time, neutrinos made up 10% of the universe, atoms 12%, dark matter 63%, photons 15%, and dark energy was negligible.  In contrast, estimates from WMAP data show the current universe consists of 4.6% percent atoms, 23% dark matter, 72% dark energy and less than 1 percent neutrinos.  Cosmic neutrinos existed in such huge numbers they affected the universe’s early development. That, in turn, influenced the microwaves that WMAP observes. WMAP data suggest, with greater than 99.5% confidence, the existence of the cosmic neutrino background - the first time this evidence has been gleaned from the cosmic microwaves. 

Another breakthrough derived from WMAP data is clear evidence the first stars took more than a half-billion years to create a cosmic fog.  The data provide crucial new insights into the end of the "dark ages," when the first generation of stars began to shine.  The glow from these stars created a thin fog of electrons in the surrounding gas that scatters microwaves, in much the same way fog scatters the beams from a car’s headlights. 

A third major finding arising from the new WMAP data places tight constraints on the astonishing burst of growth in the first trillionth of a second of the universe, called “inflation”, when ripples in the very fabric of space may have been created.  Some versions of the inflation theory now are eliminated; others have picked up new support.

ACE

The Advanced Composition Explorer (ACE), launched on August 25, 1997, is positioned in a halo orbit around the first Langrangian libration point L1, where gravitational forces are in equilibrium.  By end-2007, ACE has been at the L1 point for more than ten years, and the spacecraft and instruments are still working very well, with the exception of the SEPICA (Solar Energetic Particle Ionic Charge Analyzer) instrument.  Due to failure of the valves that control gas flow through the instrument, active control of SEPICA’s proportional counter is no longer possible.  The ACE spacecraft remains healthy, and a fuel use strategy has been implemented that will allow continued operations through the year 2022.  

During 2007,  ACE continued to observe, determine and compare the isotopic and elemental composition of several distinct samples of matter, including the solar corona, the interplanetary medium, the local interstellar medium and galactic matter.  With a semi-major axis of approximately 200,000 km, its elliptical orbit affords ACE a prime view of the Sun and the galactic regions beyond, from a vantage point approximately 1/100th of the distance from the Earth to the Sun.   

During the coming years multi-point data from ACE, STEREO, and other spacecraft will provide a new perspective on anomalous cosmic ray (ACR) studies by measuring the longitudinal structure and distribution of interplanetary coronal mass ejections (ICMEs), interplanetary (IP) shocks, solar energy particle (SEP) events and suprathermal ions, and by correlating these in situ observations with multi-point imaging of the corona and inner heliosphere.

Ulysses

In 2007, the joint European/NASA solar polar mission Ulysses celebrated its 17th launch anniversary.  Carried into space on 6 October 1990 by the space shuttle Discovery (STS-41), the Ulysses spacecraft has already travelled an amazing 7 billion km and at this time is still going strong.  On November 17, 2006, the spacecraft reached another important milestone on its epic out-of-ecliptic journey: the start of the third passage over the Sun's south pole.  Ulysses is engaged in the exploration of the heliosphere, the bubble in space blown out by the solar wind.  The first polar passes in 1994 (south) and 1995 (north) took place near solar minimum, whereas the second set occurred at the height of solar activity in 2000 and 2001.  Ulysses carries a comprehensive suite of sophisticated scientific instruments, several of which are of a kind never flown in space before.  In addition to enabling the mission’s “core business” - providing the first survey of the solar wind in four dimensions (three spatial dimensions and time) - this combination has enabled scientists to make many groundbreaking discoveries, some in areas that were not even imagined when the mission was first planned.  Ulysses “firsts” include: First direct measurements of interstellar dust and neutral helium gas, first measurements of rare cosmic-ray isotopes, first surveys of the space environment above and below the solar poles, first measurements of so-called “pickup” ions of both interstellar and near-Sun origin, first in-situ observations of comet tails at large distances from the Sun, and first observations of particles from solar storms over the solar poles.  At end-2007, after almost four times its expected mission lifetime, the venerabvle spacecraft was approaching the end of its operations.  Since its Jupiter flyby in 1992, Ulysses has been in a six-year orbit around the sun. Its long path through space carries it out to Jupiter's orbit and back. The farther it ventures from the sun, the colder the spacecraft becomes, but its heating capability is running out: Ulysses is powered by the decay of a radioactive isotope, and over its 17-plus years, the power has been steadily dropping.  When its temperature reaches 2 degrees Celsius, the spacecraft will be impossible to maneuver, and the mission will end, probably in 2008.

Voyager

The Voyager missions, now in their 31st year, continue their quest to push the bounds of space exploration.  The twin Voyager 1 & 2 spacecraft opened new vistas in space by greatly expanding our knowledge of Jupiter and Saturn.  Voyager 2 then extended the planetary adventure when it flew by Uranus and Neptune, becoming the only spacecraft ever to visit these worlds.  In 2006, Voyager 1, already the most distant human-made object in the cosmos, passed a major milestone when it surpassed the 100 astronomical units (AU) distance from the Sun (August 15), i.e., the spacecraft, which launched nearly three decades ago, was 100 times more distant from the sun than Earth is.  At that time Voyager 1 was about 15 billion kilometers (9.3 billion miles) from the sun.  The Voyagers owe their longevity to their nuclear power sources, called radioisotope thermoelectric generators (RTGs).  Both Voyagers are still working, 24 hours a day, seven days a week.  The spacecraft are now traveling at a distance where the Sun is but a bright point of light and solar energy is not an option for electrical power.  Voyager 1 is at the outer edge of our solar system, in an area called the heliosheath, the zone where the sun's influence wanes.  This region is the outer layer of the “bubble” surrounding the sun, and no one knows how big this bubble actually is.  Voyager 1 is literally venturing into the great unknown and is approaching interstellar space.  Traveling at a speed of about one million miles per day, Voyager 1 could cross into interstellar space within the next 10 years. 

The Voyager 2 spacecraft has followed its twin into the solar system's final frontier, a vast region at the edge of our solar system where the solar wind runs up against the thin gas between the stars, but has taken took a different path.  In 2007, it entered the heliosheath on August 30 at a distance of 84 astronomical units (AU) from the Sun (1 AU is the distance between the Earth and Sun).  By comparison, Pluto is now about 32 AU from the Sun.  Voyager 2 actually crossed the boundary five times and was directly observed (unlike Voyager 1) making the passage three of those times.  That is because the location of the termination shock is constantly changing in response to the Sun's activity.  Plasma burps from the Sun called coronal mass ejections (CMEs) temporarily push the boundary outwards, for example, so that it washes back and forth over the spacecraft like a wave on the beach.  An instrument on the spacecraft measured the abrupt slowdown of the solar wind that defines the termination shock.  But the shock did not look the way it was expected to: instead of seeing a very abrupt drop, the spacecraft observed a gradual slowing of the solar wind ahead of each crossing, followed by a relatively small drop at the termination shock itself.  Mission scientists are not sure how to explain the gradual slowdown preceding the shock.  Neutral atoms from beyond the termination shock may be interacting with the solar wind to produce speedy charged particles called cosmic rays, thereby sapping some of the wind's energy.

Because Voyager 2 crossed the heliosheath boundary, called the solar wind termination shock, about 16 billion kilometers (10 billion miles) away from Voyager 1 and almost 1.6 billion kilometers (one billion miles) closer to the Sun, it confirmed that our solar system is “squashed” or “dented”– that the bubble carved into interstellar space by the solar wind is not perfectly round.  Where Voyager 2 made its crossing, the bubble is pushed in closer to the Sun by the local interstellar magnetic field.

One or the other of the spacecraft will become the first probe to reach interstellar space after a travel period scientists estimate to be about 7-10 years long.  It is not clear which spacecraft will be first, even though Voyager 1 is about 20 AU farther from the Sun than its sister spacecraft.  Voyager 1 is escaping the solar system at a speed of about 3.6 AU per year and Voyager 2 is covering about 3.3 AU per year.  Both spacecraft are expected to continue to operate and send back valuable data until at least the year 2020.  The adventurers' current mission, the Voyager Interstellar Mission (VIM), will thus explore the outermost edge of the Sun's domain.  And beyond.

Mars exploration.

The main event in 2007 for NASA’s Mars program was the launch of yet another unmanned exploration probe, Phoenix, to the Red Planet, joining five other spacecraft currently studying Mars: Mars Reconnaissance Orbiter, Mars Express, Mars Odyssey, and two Mars Exploration Rovers.  This is largest number of active spacecraft to study another planet in the history of space exploration.

Phoenix.   Launched on August 4 on a Delta-2 from Florida, the Phoenix Mars mission is the first in NASA's Scout Program.  During 2007, Phoenix coasted in its cruise phase, which lasts for approximately 10 months.  During the cruise, the spacecraft has continuously verified the health of its scientific instruments and performed trajectory correction maneuvers (TCMs).  The robotic lander is scheduled to arrive at the Red Planet on May 25, 2008, and begin a close examination of Mars' northern polar region.  Phoenix will be the first mission to touch the planet's water-ice.  Its robotic arm will dig into an icy layer believed to lie just beneath the Martian surface.  The robot explorer will study the history of the water in the ice, monitor weather in the polar region, and investigate whether the subsurface environment in the far-northern  plains of Mars has ever been favorable for sustaining microbial life.   The Phoenix mission uses the Mars Surveyor 2001 Lander, built in 2000, but later administratively mothballed.  The '01 lander has undergone modifications to improve the spacecraft's robustness and safety during entry, descent, and landing.  Phoenix also uses two instruments delivered for the '01 lander that have been in protected storage: the MECA (Microscopy, Electrochemistry, and Conductivity Analyzer), and MARDI (Mars Descent Imager).  However, due to a problem discovered late in the Phoenix lander ground testing program, it was decided not to use the MARDI (and an also included audio microphone during descent).  In addition, the RA (Robotic Arm) has been modified from the '01 lander version.  From the Mars Polar Lander, which failed to return data upon its arrival at Mars' antarctic region on December 3, 1999, Phoenix uses three instruments, the SSI (Surface Stereo Imager), the RA, and the TEGA (Thermal and Evolved Gas Analyzer). 

Mars Reconnaissance Orbiter (MRO).   MRO is a multipurpose spacecraft designed to conduct reconnaissance and exploration of Mars from orbit.  The $720 million spacecraft was built by Lockheed Martin under the supervision of NASA’s Jet Propulsion Laboratory (JPL).  It was launched on August 12, 2005, on an Atlas V launch vehicle and arrived at Mars on March 10, 2006, after a 300 million-mile trip, taking more than 35 hours to circle the planet in its initial very elongated (elliptic) orbit for subsequent aerobraking maneuvers to achieve a lower circular orbit.  MRO began its its primary science phase in November 2006.  In February 2007, it had already surpassed the record for the most science data returned by any Mars spacecraft.  The mission continued to produce data at record levels. 

During 2007, engineers dealt with some onboard problems, such as a software error between the MRO and one of its instruments, an event which on July 17 caused the spacecraft to turn off two of its science instruments--the MCS (Mars Climate Sounder) and CRISM (Compact Reconnaissance Imaging Spectrometer for Mars).  A few days later, spacecraft and instruments were brought back to normal operations.  By November, the orbiter had returned enough data to fill nearly 1,000 CD-ROMs.  This tied the record for Mars data sent back between 1997 and 2006 by NASA's Mars Global Surveyor (MGS) mission: about 30 terabits of science data, including more than 15,000 images from three cameras, more than 3,000 targeted observations by a mineral-mapping spectrometer, and more than 2,200 observations with ground-penetrating radar. 

Among its findings are some of the weirdest landscapes on Mars as well as more familiar-looking parts of the Red Planet: One type of landscape near its south pole is called "cryptic terrain" because it once defied explanation, but new observations bolster and refine recent interpretations of how springtime outbursts of carbon-dioxide gas there sculpt intricate patterns and paint seasonal splotches.  In addition to radially branching patterns called "spiders," which had been detected by an earlier Mars orbiter, other intriguing ground textures in the area appear in the new images.  Results from all six instruments on the MRO were described in dozens of presentations in November by planetary scientists in San Francisco at the fall meeting of the American Geophysical Union (AGU).

Spirit (MER-A) & Opportunity (MER-B).   By end-2007, the twin Mars rovers were 46 months into missions originally planned to last three months.  The six-wheeled rover vehicle Spirit, launched on June 10, 2003, on a Delta-2/Heavy rocket, landed on January 3, 2004 (ET) almost exactly at its intended landing site in Gusev Crater in excellent condition.  Opportunity, NASA’s second Mars explorer and twin to Spirit, launched on July 7, 2003 (ET), also on a Delta-2/Heavy after a “cliffhanger” countdown, touched down on January 25, 2004, right on target on Meridiani Planum, halfway around the planet from the Gusev Crater site of its twin, also in excellent condition.

At end-2007, the twin rovers, nearing the fourth anniversary of their landings, were getting smarter as they got older.  But they faced their biggest challenges yet: for nearly a month, mostly during July, a series of severe Martian summer dust storms affected Opportunity and, to a lesser extent, Spirit.  Dust in the atmosphere over Opportunity blocked 99% of direct sunlight to the rover, leaving only limited and diffuse sky light to power it.  Fortunately, the storm abated, and on August 21, Opportunity resumed driving toward Victoria Crater in Mars' Meridiani Planum region and began descending into the crater in September.  At approximately 800 meters (half a mile) wide and 70 meters (230 feet) deep, it is the largest crater the rover has visited.  On August 23, Spirit maneuvered into position for driving up to the top of a rock platform called “Home Plate”, its long-term destination in a range of hills that were on the distant horizon from its landing site, and in September climbed onto this a plateau of layered volcanic bedrock bearing clues to an explosive mixture of lava and water.

Late in 2007, NASA extended, for a fifth time, the activities of the two rovers, keeping the trailblazing mobile robotic pioneers active on opposite sides of Mars, possibly through 2009.  By end-2007, Spirit had driven about 7.5 kilometers (4.7 miles) and returned more than 102,000 images.  Opportunity had driven 11.7 kilometers (7.3 miles) and returned more than 94,000 images.

Among the rovers' many other accomplishments:  Opportunity has analyzed a series of exposed rock layers recording how environmental conditions changed during the times when the layers were deposited and later modified: wind-blown dunes coming and going, water table fluctuating.  Spirit has recorded dust devils forming and moving.  The images were made into movie clips, providing new insight into the interaction of Mars' atmosphere and surface.  Both rovers have found metallic meteorites on Mars.  Opportunity discovered one rock with a composition similar to a meteorite that reached Earth from Mars.

After Spirit and Opportunity, NASA’s next-generation Mars mission, to land in the Martian arctic in May 2008, is the Phoenix Mars Lander, followed by the next rover, the Mars Science Laboratory, currently in development for launch in 2009.

Mars Odyssey.   NASA’s Mars Odyssey probe, launched April 7, 2001, reached Mars on October 24, 2001, after a six-month and 286-million mile journey.  Entering a highly elliptical orbit around the poles of the Red Planet, it began to change orbit parameters by aerobraking, reducing its ellipticity to a circular orbit at 400 km by end of January 2002.  The orbiter is circling Mars, with the objective to conduct detailed mineralogical analyses of the planet's surface from space and measuring the radiation environment. 

In 2007, Odyssey was in its second extended mission, continuing to perform scientific observations and also serving as the primary communications relay for NASA's Mars rovers.  During the year, when Odyssey reported that a power processing component of the backup, or "B-side," systems had stopped working, engineers examined whether onboard backup systems never used by the 6-year-old spacecraft could still be available if needed: the component, the high-efficiency power supply, has a twin that is continuing to serve the "A-side" hardware, which is operating normally.  In September, the ground team returned the spacecraft to full service after Odyssey once more put itself into the standby "safe mode" in response to a root cause that engineers have diagnosed as the same cause as for two previous safe mode entries, in 2005 and 2006: a messaging interface system that got temporarily stuck, leaving the flight computer to assume (wrongly) that an attitude control task was no longer running.  Afterwards, the spacecraft pointed its instruments and UHF relay antenna properly toward Mars, to resume relaying communications from the Mars rovers and using its own science instruments.  The rovers can communicate directly with Earth when Odyssey is unavailable for relay.

Earth Science

In 2007, NASA launched five Earth science satellites, THEMIS 1-5, two more than in 2006, all of them dedicated to one mission: the study of Earth’s auroras.  There were also two dual-use (civil & miltary) earth observation satellites launched on US Delta-2 rockets: COSMO-Skymed-1 (Constellation of Small satellites for Mediterranean basin observation) and COSMO-Skymed-2 for the Italian Space Agency (ASI).

THEMIS 1-5

After launch of NASA's THEMIS (Time History of Events and Macroscale Interactions during Substorms) mission on February 17 on a Delta-2 rocket, the five THEMIS spacecraft were deployed into a ‘string-of-pearls’ configuration on near-identical highly elliptical orbits with 31-hour periods.  THEMIS investigates what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color.  Discovering the cause of the change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection.  The five-craft THEMIS fleet may help scientists to determine why auroras are more common in the spring than at other times.  The first science observations from the spacecraft were obtained on March 23, during a disturbance in the Earth’s magnetic field known as a substorm.  The multipoint spacecraft and dedicated ground observatories allowed researchers to track the development of the substorm via a proof-of-concept study demonstrating novel techniques that will be used throughout the course of the mission.  All 25 instruments on each spacecraft have been operating well ever since.  Their data confirmed the existence of giant magnetic ropes and witnessed small explosions in the outskirts of Earth's magnetic field. 

During 2007, the spacecraft were in a “coast phase” collecting information about the interaction of the solar wind and the Earth’s magnetic field.  At maximum distance from Earth (apogee), the spacecraft lie between the Sun and the Earth.  On their way out to and back from apogee each orbit, the spacecraft routinely cross the outer boundary of the Earth's magnetic field and a shock wave that stands upstream from this boundary.  Scientists are taking this opportunity to study the outer boundary, known as the magnetopause, and determine how the Sun's plasma and magnetic energy couples into the Earth's environment.  The first discoveries of the dynamics of a rapidly developing substorm were presented at the annual meeting of the American Geophysical Union (AGU) in San Francisco in December.

CloudSat

CloudSat is an experimental mission conducted jointly by NASA and the Canadian Space Agency (CSA) to study the effects of clouds on climate and weather with capabilities 1,000 times more sensitive than typical weather radar, using millimeter-wavelength radar to measure the altitude and properties of clouds.  This information is providing the first global measurements of cloud properties that will help scientists compile a database of cloud measurements, aiding in global climate and weather prediction models.  The 2202-lb (999-kg) CloudSat was launched with the CALIPSO satellite by a Delta-2 from VAFB on April 28, 2006, into a polar orbit at an altitude of 438 miles (705 km).  Both spacecraft are part of a constellation of spacecraft called the "A-Train," including Aqua, Aura and PARASOL, dedicated to studying the Earth’s weather and environment, with CloudSat orbiting approximately one minute behind Aqua.  CloudSat will complete its 22-month prime mission in 2008 (February 27), possibly to go into an extended mission phase.

From its initial transition to operational mode on June 2, 2006, through the end of 2007, CloudSat has collected close to 9000 granules (orbits) of data, including 300 million radar profiles and about 45 billion individual radar bins (vertical measurements). The CloudSat Data Processing Center has distributed over 1,500,000 product files, totaling 100 terabytes of data to scientists in 47 different countries.  The new observations collected from CloudSat combined with other A-Train observations are beginning to shed new understanding on important climate processes, in particular about (1) cloud changes in the polar regions, and the effects of these changes on the energy balance of the Arctic, their relation to weather changes and their role in sea ice change, (2) how frequently clouds rain and how much rain falls over the global oceans - thus offering insight into processes critical to the cycling of fresh water, and (3) how properties of clouds AND precipitation together change with increasing aerosol, thus offering new insights into how aerosol might indirectly affect climate.  The mission is.

CALIPSO

Highly complementary with CloudSat, the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) satellite continued in 2007 to provide new insight into the role that clouds and atmospheric aerosols (airborne particles) play in regulating Earth's weather, climate, and air quality.  CALIPSO was launched into orbit around the Earth along with CloudSat as part of the "A-train," a constellation of Earth observing satellites.  CALIPSO provides the next generation of climate observations, including an advanced study of clouds and aerosols, drastically improving our ability to predict climate change and to study the air we breathe.  Its payload includes three co-aligned nadir-viewing instruments: (1) the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP, pronounced the same as “calliope”) to provide vertical profiles of aerosol and cloud backscatter and depolarization; (2) an Imaging Infrared Radiometer (IIR) with three channels in the infrared window region optimized for retrievals of cirrus particle size; and (3) the Wide Field Camera (WFC), a moderate spatial resolution imager with one visible channel which provides meteorological context and a means to accurately register CALIPSO observations to those from MODIS on the Aqua satellite.  These instruments are designed to operate autonomously and continuously, although the WFC acquires data only under daylight conditions.  Science Data are downlinked using an X-band transmitter system which is part of the payload.  CALIPSO is a joint U.S. (NASA) and French (Centre National d'Etudes Spatiales-CNES) satellite mission with an expected 3 year lifetime.

GOES-N

The National Oceanic and Atmospheric Administration (NOAA)/NASA joint mission GOES-N which was launched aboard a Delta 4 rocket from CCAFS, Florida, on May 24, 2006 into geosynchronous orbit of approximately 22,300 miles, continues to be available in its current “on-orbit storage” mode from where it will be able to more rapidly replace a failure of any existing operational GOES (Geostationary Operational Environmental Satellites) such as GOES-12 at GOES-EAST or GOES-11 at GOES-WEST, circa 2010.  Later, GOES-N is aimed at becoming the primary U.S. hurricane-monitoring spacecraft.  GOES-N, to be renamed GOES-13, is the latest in a series of Earth monitoring satellites which provide the kind of continuous monitoring necessary for intensive data analysis.  Being in a geostationary orbit allows GOES satellites to hover continuously over one position on the Earth's surface, appearing stationary.  As a result, GOES provide a constant vigil for the atmospheric "triggers" for severe weather conditions such as tornadoes, flash floods, hail storms, and hurricanes.

NOAA-18

After its launch on May 20, 2005, on a Boeing Delta-2 expendable rocket, the NOAA-18 environmental satellite for NOAA in 2006 continued to operate in excellent condition, circling the Earth in a polar orbit of 870 km (544 s.mi.) altitude and 98.73 degrees inclination.  With the objective to improve weather forecasting and monitor environmental events around the world, NOAA-18 continued in 2007 to collect data about the Earth's surface and atmosphere.  Operators were encountering some noisy housekeeping telemetry, with no significant impact on science data.  NOAA-18 has instruments used in the 1982-established international Search and Rescue Satellite-Aided Tracking System, called COSPAS-SARSAT.  NOAA polar-orbiting satellites detect emergency beacon distress signals and relay their location to ground stations, so rescue can be dispatched.

Aura

Aura (Latin for “breeze”), launched from Vandenberg AFB on July 15, 2004, on a Delta-2 rocket, is NASA’s third major Earth Observing System (EOS) platform, joining its sister satellites Terra and Aqua, to provide global data on the state of the atmosphere, land, and oceans, as well as their interactions with solar radiation and each other.  Aura’s design life is five years with an operational goal of six years.  The satellite flies in formation about 15 minutes behind Aqua. 

During 2007, scientists continued to use Aura and other satellites for tracking different chemicals present in Earth's atmosphere.  These data are giving researchers a more complete picture of the causes and effects of atmospheric pollution.  The scientists combined atmospheric models with actual measurements of ozone, carbon monoxide and nitrogen dioxide in Earth's lower atmosphere.  The Ozone Monitoring Instrument on the Aura satellite measures the total amount of ozone from the ground to the upper atmosphere over the entire Antarctic continent.

ICESat

ICESat (Ice, Cloud, and land Elevation Satellite), also an Earth Observing System (EOS) spacecraft, is the benchmark mission for measuring ice sheet mass balance, cloud and aerosol heights, as well as land topography and vegetation characteristics.  Launched on January 12, 2003, on a Delta-2 Expendable Launch Vehicle (ELV) into a near polar orbit at an altitude of 600 km with an inclination of 94 degrees, the spacecraft in 2007 continued to provide data from its one instrument,- the Geoscience Laser Altimeter System (GLAS).  Scientists trying to understand the dynamics of the Earth are using the lasers of ICESat to measure the height of ice sheets, glaciers, forests, rivers, clouds and atmospheric pollutants from space with unprecedented accuracy, providing a new way of understanding our changing planet.  GLAS sends short pulses of green and infrared light though the sky 40 times a second, all over the globe, and collects the reflected laser light with a one-meter telescope, yielding elevations. It also fires a fine laser beam of light that spreads out as it approaches the Earth surface to about 65 meters in diameter.  On its way to the surface, those photons or particles of light bounce off clouds, aerosols, ice, leaves, ocean, land and more providing detailed information on the vertical structure of the earth system.

Aqua

Launched in May 2002, the 1750 kg (3858 lb) NASA satellite Aqua, formerly named EOS PM (signifying its afternoon equatorial crossing time), carrying six instruments weighing 1082 kg (2385 lb) designed to collect information on water-related activities worldwide, has been circling Earth in a polar, sun-synchronous orbit of 438 miles (705 km) altitude.  During its six-year mission, Aqua is observing changes in ocean circulation and studies how clouds and surface water processes affect our climate.   NASA and NOAA scientists, working with experimental data from Aqua’s Atmospheric Infrared Sounder, a high-spectral resolution infrared instrument that takes 3-D pictures of atmospheric temperatures, water vapor and trace gases, are conducting research on improving the accuracy of medium-range weather forecasts in the Northern Hemisphere.  Incorporating the instrument's data into numerical weather prediction models improves the accuracy range of experimental six-day Northern Hemisphere weather forecasts by up to six hours, a four-percent increase.  These data have now been officially incorporated into the NOAA National Weather Service operational weather forecasts.

POES-M (NOAA-M)

The operational weather satellite POES-M (Polar-orbiting Operational Environmental Satellites-M) was launched from VAFB on a commercial Titan 2 rocket on June 24, 2002.  The satellite, later renamed NOAA-M, is part of the POES program, a cooperative effort between NASA and NOAA, the United Kingdom (UK), and France.  It joined the GOES-M launched in July 2001.  Both satellites, operated by NOAA, in 2007 continued to provide global coverage of numerous atmospheric and surface parameters for weather forecasting and meteorological research.  NOAA-M broadcasts data directly to thousands of users around the world, using its environmental monitoring instruments for imaging and measurement of the Earth's atmosphere, its surface, and cloud cover. Observations include information about Earth radiation, sea and land surface temperature, atmospheric vertical temperature, water vapor, and ozone profiles in the troposphere and stratosphere.

GRACE.

Launched on March 17, 2002, on a Russian Rockot carrier, the twin satellites GRACE (Gravity Recovery and Climate Experiment), named "Tom" and "Jerry", in 2007 continued to map the Earth's gravity fields by taking accurate measurements of the distance between the two satellites, using Global Positioning System (GPS) and a microwave ranging system.  This allows making detailed measurements of Earth's gravity field, which will lead to discoveries about gravity and Earth's natural systems with possibly far-reaching benefits to society and the world's population.  Among other things, GRACE in its five years of operation may have found a crater deep under the Antarctic ice that may mark an asteroid impact greater than the one that doomed the dinosaurs, measured the seafloor displacement that triggered the tsunami of 2004, and quantified changes in subsurface water in the Amazon and Congo river basins.  GRACE provides scientists from all over the world with an efficient and cost-effective way to chart the Earth's gravity fields with unprecedented accuracy, yielding crucial information about the distribution and flow of mass within the Earth and its surroundings.  The science data from GRACE consist of the inter-satellite range change measurements, and the accelerometer, GPS and attitude measurements from each satellite.  In December 2005, the twin GRACE satellites have exchanged positions, and GRACE-1 became the trailing satellite.  The swap was done to mitigate the risk of loss of thermal control over the K-band antenna horn (and subsequent spurious K-band range signal) due to atomic oxygen exposure.  After the two satellites switched position, a special data collection campaign for the inter-satellite separation between about 70 km and about 170 km got underway. The mean inter-satellite separation is usually bound between 170 and 270 km, but the closer mean separation is expected to enhance the high-frequency signal content in the K-band range measurements. 

After data from the GRACE satellites in the first-ever gravity survey of the entire Antarctic ice sheet showed that the ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, in 2007 the GRACE mission received the prestigious William T. Pecora Award for outstanding contributions toward understanding the Earth through remote sensing from the U.S. Department of the Interior and NASA.  The project is a joint partnership between NASA and the German DLR (Deutsches Zentrum für Luft- und Raumfahrt).  

Department of Defense space activities.   

United States military space organizations continued their efforts to make space a routine part of military operations across all service lines.  One focus concerns plans for shifting the advanced technology base toward space in order to continue building a new foundation for more integrated air and space operations in the 21st century as space is becoming increasingly dominant in military reconnaissance, communications, warning, navigation, missile defense and weather-related areas.  The increased use of satellites for communications, observations, and – through the GPS – navigation and high-precision weapons targeting was and is of decisive importance for the military command structure.  Consequently, main U.S. Air Force (USAF) attention in 2007 continued to be on addressing space acquisition problems such as the ones posed by the missile warning program SBIRS (Space Based Infrared System), eventually to replace the DSP-23 constellation, with some significant progress made.  By end-2007, USAF could point to a continued succession of more than 54 successful launches of operational satellites. 

In 2007, the Operationally Responsive Space (ORS) Office, called for by the U.S. Congress in 2006, was created under the Dept. of Defense Executive Agent for Space.  Work progressed on the development of two major satellite contracts in 2008,- for the GPS 3 navigation satellites and the T-Sat (Transformational Satellite) Communications System. 

Highlights of military space in 2007 included the launch of the first USAF Wideband Global System (WGS) broadband communications satellite which marked a major step in military capabilities, on an Atlas-5 (Oct. 11).  There were eight successful military space launches (2006: 7; 2005: 6; 2004: 5; 2003: 11), carrying 15 payloads: one heavy Delta-4M vehicle, launching a DSP-23 early warning satellite, two Delta-2 launchers carrying two new GPS IIR navigation satellites (-17/M4 & -18/M5), four Atlas-5 rockets, one with eight individual payloads (mostly nanosatellites), two with classified NROL surveillance satellites plus one with the WGS, and one OSC Minotaur launcher with an experimental satellite (NFIRE).  The ninth launch, a failure, was the second Falcon-1 rocket from SpaceX, with an USAF Demo payload.

Commercial space activities.   

In 2007, commercial space activities in the United States reached its lowest level since several years, to some extent due to the export restrictions imposed to the US industry on sensitive technologies.  Of the 19 total launch attempts by the United States in 2007 (23 in 2006, 16 in 2005, 19 in 2004, 26 in 2003), only one (5.3%) was a commercial mission (NASA/civil: 9; military: 9): a Delta-2 rocket with the Worldview-1 imaging satellite, the world’s only commercial satellite with a half-meter image resolution.  The “non-US/non-Russian” partnership of Boeing, RSC-Energia (Russia, 25% share), NPO Yushnoye (Ukraine) and Kvaerner Group (Norway) launched one Russian Zenit 3SL (SeaLaunch) rocket carrying the NSS-8 (New Skies 8), the eighth comsat in a series intended to provide global coverage at C-band. but rocket and payload were destroyed at launch on January 30.  The newcomer SpaceX sustained the second failure of its new Falcon 1 rocket during ascent to orbit on March 21 for the USAF.