A computer problem aboard the space station Mir threatens to delay the Tuesday launch of space shuttle Discovery, which is to rendezvous with the Russian space station.
CBS News Space Consultant Bill Harwood reports that a replacement control computer installed aboard Mir Sunday either is not working properly or is the victim of a malfunction somewhere else in the system. The computer, which had malfunctioned Saturday, is needed to keep Mir properly oriented toward the sun.
"We've got to understand it before we proceed," National Aeronautics and Space Administration spokesman Bruce Buckingham said Sunday night.
Discovery is scheduled to take off Tuesday on NASA's ninth and final ferry flight to the Russian outpost. But the space shuttle cannot dock with Mir unless the station's computer-controlled steering system is working and keeping the space station steady.
"It's left them kind of scratching their heads," Buckingham said.
NASA's mission management team is scheduled to meet at 10 a.m. Monday. If Russian flight controllers do not have a solution in hand by then, Harwood reports, Discovery's countdown likely will be put on hold. Discovery must be off the ground by June 7 or the flight will be delayed until June 11, after a commercial Delta rocket launch June 9.
Meanwhile, the Mir's crew is in no danger. The station has plenty of power for its major life-support systems, and a Soyuz entry vehicle is available if some other failure forced the crew to abandon ship.
Frank Culbertson, director of NASA's shuttle-Mir program, said the American astronaut aboard Mir, Andrew Thomas, was a little antsy about the chance that his ride home might be delayed.
"He's just waiting for the next shoe to fall," Culbertson said. "But we're going to go get him."
Thomas, 46, the seventh and final NASA astronaut to visit Mir, has been living on the aging space station since January.
Mir's motion-control computer failed Saturday after working fine for five months. When the cosmonauts tried to restart it Sunday, they got an equipment alert and shut it down, Culbertson said. The spare computer they replaced it with was taken up on the last shuttle ferry flight in January. The crew has yet another spare computer on board.
Unlike earlier motion-control failures experienced last year and in January, the failure Saturday did not cause the station to drift very far away from its normal orientation, Harwood reports.
As a precaution, Thomas and his two Russian crewmates kept the air conditioner and primary oxygen geerator shut down to conserve stored power.