NASA Pulls Plug on Ultraviolet Telescope

The procedure turned FUSE's passive magnetic torque bars into an active spacecraft control system. The bars, which are 3-foo long, 1 1/2-foot diameter steel rods with a ferrite core, were used to push or pull against Earth's magnetic field so the momentum wheels would have an outside force to transfer their excess energy to.

With new software, the telescope was resurrected. Then engineers began planning for the next failure: the loss of FUSE's gyroscopes, which let the telescope know what position it is in. For that fix, engineers made use of a camera on the telescope that finds guide stars for positioning information.

FUSE's troubles and triumphs continued until July 12 when the last flywheel suddenly failed. Ground controllers worked for a month trying to restart the system, to no avail.

"Once we lost that last wheel, basically we could hold it steady in a safe mode, but we couldn't do any science," Blair said.

On Aug. 14, the lead scientist sent a note to NASA recommending the termination of FUSE science operations.

"It is a sad day for the FUSE project," Blair wrote that day in his Weblog.

"It has been a wild ride, but it looks like we are pulling into the station," he said. "It will soon be time to step off this roller coaster and find a new one to climb onto."

Scientists interested in the far ultraviolet view of the universe will have to content themselves with FUSE archive data for the foreseeable future. NASA has no similar replacement telescope in the works.

NASA's partners in FUSE are the Canadian Space Agency and the Centre National d'Etudes Spatiales in Toulouse, France.

FUSE findings

Blog: The End Is Near

The FUSE Telescope homepage