When launched in 2010, a football-field-in-length demonstrator radar antenna, weighing more than 5 tons, will serve as the forerunner for the future of America's intelligence, surveillance and reconnaissance assets in space.

Administered by the Air Force Research Laboratory's Space Vehicles Directorate here, the innovative space-based radar antenna technology, or ISAT, program focuses on developing systems to deploy extremely large (up to 300 yards) electronically scanning radar antennas flying 5,700 miles above the Earth's surface and providing improved ground target detection to the warfighter.

"These huge antennas will enable the revolutionary performance required to conduct tactical sensing from space, including missions like continuous and reliable tracking of surface targets," said Dr. Steven A. Lane, ISAT program manager. "Since it uses radar, it is not limited by cloud coverage and can operate at night, unlike optical systems."

Originated in 2002, and sponsored by the Defense Advanced Research Projects Agency at Arlington, Va., the ISAT program also involves participation by the laboratory’s sensors directorate at Wright-Patterson AFB, Ohio, and information directorate at Rome Laboratory, N.Y., as well as NASA's Langley Research Center at Langley Va., and Jet Propulsion Laboratory in Pasadena, Calif.

In addition, two contractor teams -- Boeing Co. and Raytheon Co., as well as Lockheed Martin Corp. and Harris Corp. -- are competing to build the 100-yard-sized flight experiment. Following the spacecraft's critical design review process in June, DARPA will select one of the contractor pairings to advance the project, with recommendations from the space vehicles directorate.

Operated out of Detachment 12 of the Space and Missile Systems Center here, the DOD Space Test Program will furnish the evolved expendable launch vehicle flight opportunity, referred to as STP-2, to propel the large, foldable ISAT flight demonstrator into low Earth orbit, about 620 miles above the planet. Det. 12 will also operate the spacecraft from the Research, Development, Test and Evaluation Support Complex here.

However, before the planned liftoff occurs at Cape Canaveral, Fla., in four years, the ISAT spacecraft will be developed, integrated and tested at the contractor facility with oversight provided by the space vehicles directorate.

Technologies to be developed and demonstrated on the ISAT flight experiment include advanced antenna architectures and structures; lightweight radiation-hardened materials and electronics; reliable deployment technologies and mechanisms; compressible components and materials; as well as advanced metrology and calibration concepts for large radar antennas.

The multimillion-dollar project's primary goal, however, is assisting the warfighter through development of tactical grade, ground-moving target indication capability. This ISR tool will enable the tracking and identifying of targets with precise resolution and scanning in multiple areas of interest.

"The primary reason that the space vehicles directorate was selected to carry out this flight experiment for DARPA is our rich history and expertise in each of these technology areas. We can apply years of research and engineering conducted for other programs toward the successful completion of ISAT," Dr. Lane said.

The 20-plus member government ISAT management team is currently working on ensuring the demonstrator's successful mission in 2010. To achieve this objective, the group has concentrated on four specific project areas: structures, radar, metrology and calibration, as well as systems engineering, integration, and testing.

Because of the antenna's large size, which prevents ground testing of the integrated system before launch, there is an unprecedented emphasis on modeling, simulation and ground-based risk-reduction demonstrations. These will play a crucial role in the flight experiment's outcome.

"During its projected one year mission, the ISAT flight experiment will test enabling technologies and gather information critical for the eventual development of an operational system," Dr. Lane said. "One of the key benefits of this experiment is that we will improve our modeling and simulation paradigm for large deployables (extremely large, light-weight structures), which will benefit many future missions beyond ISAT."

(Courtesy of Air Force Materiel Command News Service)