Headlines

Bill Ailor, fourth from left, joins the CORDS team by a 260-kilogram stainless-steel fuel tank that returned to Earth after nine months in space.

Black Box for Spacecraft

In an effort to pinpoint sites where space debris will land on Earth, The Aerospace Corporation's Center for Orbital and Reentry Debris Studies (CORDS) is working with the Air Force Space and Missile Systems Center to develop a "black box" similar to the flight-data recorders found on commercial aircraft.

"Data obtained using a black box could provide clues as to how changes in materials and construction might prevent large pieces of space debris from hitting Earth's surface," said Bill Ailor, CORDS director.

Many spacecraft, or pieces of them, return to Earth. A black box that would survive reentry may one day give researchers information about changes in material temperatures and loads on spacecraft as they reenter the atmosphere. The box may also help determine the "footprint" or area of Earth's surface where debris will fall.

Surviving pieces of varying sizes can be spread over hundreds of miles. Many factors, including atmospheric conditions and the aerodynamic characteristics of the objects, influence the footprint location.

EELV Launches

Two successful rocket launches in the fall of 2002 inaugurated the Air Force's Evolved Expendable Launch Vehicle (EELV) program, the first new government-sponsored launch system in two decades. The Atlas V launched on August 21, and the Delta IV rocket lifted off in a spectacular night launch November 20.

In launches from Cape Canaveral Air Force Station, Florida, the Atlas V (below left) carried a commercial TV broadcasting satellite into orbit, and the Delta IV (below right) inserted a communication satellite in a nearly perfect geosynchronous transfer orbit.

"Successful first launch of each EELV system establishes the next generation space launch capability to meet the government's needs for the next 20 years," said Linda Drake, EELV general manager at Aerospace.

(Lockheed Martin Space Systems)

(The Boeing Company)

Although these were commercial missions for Eutelsat, the EELV program is managed by the Air Force Space and Missile Systems Center. The first government EELV payload, a Defense Satellite Communications System (DSCS) satellite, was scheduled to launch aboard a Delta IV from Cape Canaveral in March. Aerospace provided technical support to both initial launches and launch verification for the DSCS launch.

"Aerospace's role has grown increasingly significant since the program's inception in 1995," Drake said. The corporation has provided technical insight to the Air Force throughout the EELV program development, assessing system design and qualification, monitoring launch processing, and providing launch verification for the DSCS launch.

The government-industry partnership is developing the next-generation expendable launch vehicle to give the country more reliable, affordable space transportation for the 21st century through improved operability, significant cost reduction over current systems, and a standard payload interface flexible enough to accommodate changing mission requirements.

Titan II Launches

A Titan II G-14 rocket successfully launched NOAA-M, the National Oceanic and Atmospheric Administration's newest environmental satellite, from Vandenberg Air Force Base on June 18, 2002.

After the satellite was carried to a near-perfect position in space, its apogee kick-motor provided final circularization of its near-polar orbit 450 nautical miles above Earth at an inclination of 98.7 degrees from the equator. The satellite will collect meteorological data and transmit the information to users around the world to enhance weather forecasting.

Aerospace, as sole provider of Titan II launch verification and validation for the Air Force, verified that all critical hardware, software, and mission analyses met requirements for flightworthiness. "The Titan II G-14 processing, checkout, and verification process was exceptionally smooth," said Ray Johnson, vice president of the corporation's Space Launch Operations.

Aerospace also had a role in the Titan II G-4 launch from Vandenberg in January. The mission, known as Coriolis, was sponsored by the Air Force Space Test Program and carried two experimental payloads for DOD. The first, WindSat, is reportedly the first passive sensor to measure ocean surface wind velocity. The second, the Solar Mass Ejection Imager, is an Air Force Research Laboratory experiment to forecast geomagnetic disturbances.

The Coriolis mission will last for three years. Aerospace provided technical oversight during the spacecraft's development, payload integration, and testing.

Space Shuttle Launches Mini "Satellite Inspectors"

A pair of experimental miniature satellites were launched by the space shuttle Endeavour December 2, 2002, as part of a series of test flights researchers hope will result eventually in autonomous "ride-along" spacecraft that can be released on command to inspect parent satellites.

Connected by a 15-meter nonconducting tether to facilitate detection by ground-based radar and emulate formation flying, the picosatellites were ejected from a spring-loaded launcher built by The Aerospace Corporation and installed in Endeavour's cargo bay. The miniature satellites, which measure approximately 10-by-10-by-12.5 centimeters and weigh only 1 kilogram each, were built by Aerospace in partnership with the Jet Propulsion Laboratory.

(NASA)

The launch demonstrated the capability of deploying picosat-scale satellites (1 kilogram and under) on virtually any shuttle flight. Aerospace principal investigator Ernie Robinson said that this launch capability is extremely valuable for low-cost ready access to space by anyone developing technology to picosat scale.

The diminutive satellites are serving as pathfinders for a new capability that might become the standard for conventional satellites: autonomous inspection. As envisioned by their designers, these inspection picosats will feature an onboard imaging capability and other sensors that will enable them to assess spacecraft damage and provide rapid feedback to spacecraft operators on the ground, thus helping to ensure continuous service to users and optimal spacecraft longevity.

The MEPSI project, or microelectromechanical systems (MEMS)–based picosat inspector, calls for incremental advances that will result in autonomous and fully functional inspector satellites comprising MEMS components, such as radio-frequency switches, gyros, accelerometers, and thrusters. The principal payload aboard the picosats launched December 2 consisted of inertial measurement units. During the three-day mission, the picosats transmitted signals to a ground station at Menlo Park, California, and performed inertial measurement exercises.

Aerospace Takes Part in NASA CRYSTAL-FACE Mission

The Aerospace Corporation played a key role in the recently completed airborne cloud sampling campaign of the Cirrus Regional Study of Tropical Anvils and Cirrus Layers—Florida Area Cirrus Experiment (CRYSTAL-FACE).

The campaign was part of a continuing interagency effort to better understand the ways in which aerospace propulsion-system combustion emissions affect atmospheric chemistry and radiation. Sponsored by NASA, the CRYSTAL-FACE effort extends previous joint Air Force and NASA work under the Rocket Impacts on Stratospheric Ozone (RISO) program.

"Preliminary analysis of the data has provided new insights into the size, shape, and chemical composition of cirrus and contrail ice crystals and how these clouds could affect global warming," said Martin Ross, Aerospace RISO program manager.

A south Florida thunderstorm takes on the classic "anvil" form with clouds composed of ice crystals forming a high-altitude "shield" over the entire area. A key objective of CRYSTAL-FACE was to investigate the microphysical and radiative properties of the ice particles that make up the shield. The WB-57F extensively sampled the shield cloud of this system on July 27, 2002. (NASA)

Ross served as co-flight scientist (with Randall Friedl of NASA's Jet Propulsion Laboratory) for high-altitude aircraft WB-57F payload integration and operations during CRYSTAL-FACE deployment to Key West Naval Air Station, Florida, in the summer of 2002. He directed a team of more than 100 scientists and engineers operating 27 instruments carried by the WB-57F to study how high-altitude cirrus clouds are formed, dissipate, and affect the heat balance of the lower atmosphere.

William Engblom of Aerospace applied state-of-the-art computer models to simulate the flow of air around the WB-57F during flight in an effort to understand how aircraft-induced changes in air pressure and temperature could influence the response of instruments carried by the aircraft. Highlights of the month-long CRYSTAL-FACE mission included sampling a variety of thunderstorm-related cirrus clouds, close high-altitude formation flying with the NASA ER-2, and sampling of the WB-57F's own contrail.

More detailed results from CRYSTAL-FACE will be presented at the spring meeting of the American Geophysical Union in Nice, France. The continuing collaboration between the Air Force, NASA, and other agencies under the RISO program provides the Air Force with important credibility, as well as engagement with the atmospheric science community with regard to the impacts of aircraft and rocket-engine combustion emissions on the atmosphere.

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