Status Report

DSCS-III shutdown new experience for 3rd SOPS

By SpaceRef Editor
July 13, 2005
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SCHRIEVER AFB, Colo. — In space, no one can hear you turn off a satellite.

The 3rd Space Operations Squadron satellite operators and engineers here “turned off the lights” on Defense Satellite Communications System Satellite A-2, the first satellite of its kind to be completely deactivated.

Space systems operators boosted the satellite out of geosynchronous orbit when its fuel tanks were almost empty.

Once boosted to super-synchronous orbits, satellites may be used as test platforms for software upgrades or shut down. For Satellite A-2, shutdown was the only option, said Lt. Col. Keith Hinson, 3rd SOPS commander.

DSCS engineers prepared by running simulations and verifying commands that would be sent to the satellite. However, some variables differed between the simulator and the real thing.

Each satellite handles a bit differently, said Colonel Hinson. “No two satellites are the same. You can’t just plug it into a diagnostic and say, ‘This is how we expect it to work.'”

The shutdown process started at about 4 a.m. as operators depleted the satellite’s residual fuel. Cheyenne Mountain Air Force Station, Colo., worked with 3rd SOPS to get a final orbit projection. Engineers also collaborated with the 22nd SOPS to get Air Force Satellite Control Network range time for the shutdown.

The process hit a snag around 8:45 a.m. Engineers attempted to force the satellite into an inert survival mode, however, the system aboard the satellite that normally triggers survival mode failed to activate. The team took the setback in stride and searched for a possible error in their process while they waited for the backup failsafe to kick in. “It’s a dead satellite, but we’d like it to be perfect,” said Colonel Hinson. The backup kicked in 80 minutes later, completing the satellite’s shutdown.

“The satellite’s in a completely safe configuration,” said Captain Becker, DSCS engineering chief. “All in all, it was a complete success.”

Before its shutdown, A-2 functioned as part of the DSCS constellation for 16 years — six years beyond its design life. Aging satellites are no longer useful once they run out of fuel to keep them pointed at the earth’s surface, said Colonel Hinson. However, upgrades in software control systems and new techniques for maneuvering satellites have allowed them to conserve fuel and live longer.

“These guys are incredible,” he said. “There’s no one else who can do this.”

The engineers and operators will have plenty of opportunity to do it again in the future. More satellite shutdowns scheduled in the months to come. As the military moves toward a new generation of communications systems, other DSCS-III satellites will come to rest alongside Satellite A-2 in the silence of space.

SpaceRef staff editor.