Space station repairs on main Russian computers continue

Computerworld - Continuing repairs to two Russian computers that control water, oxygen and positioning for the International Space Station hit a roadblock today when the computers could not be brought fully back online.

Bill Jeffs, a spokesman at NASA's Johnson Space Center in Houston, said the latest theory about the computer problems centers around possible electromagnetic interference from a new solar array attached to the space station yesterday. The array, used to generate electricity, was added as the station is being prepped for new research modules that will be attached over the next year, Jeffs said.

The latest array, attached to a newly-installed truss, was connected through electrical plugs to the two Russian computers that are now having problems. "Apparently they're still working on that and trying to determine if that's it," Jeffs said.

Overnight, the crew disconnected the power cables for the new truss and arrays to see if the problems would go away, and troubleshooting work is continuing, Jeffs said.

Russian technicians were able to partially get the two computers operating again using one of the three communications links, or "lanes," used by each computer to control communications about water, oxygen and the station orientation of the Russian modules of the space station.

But no further progress was made and both Russian computers -- the Russian service module terminal computer and the Russian central computer were turned off just before 6 a.m. Eastern Time today while technicians searched for clues to the problems.

The plan is to leave both machines off today to go over existing data and develop an action plan, Jeffs said.

The two computers provide backup attitude control and orbital attitude adjustment for the space station while in orbit. There are other similar computers on board, so the crew is in no imminent danger, Jeffs said. "There are plenty of other resources on board," he said.

The thrusters of the Space Shuttle Atlantis, which arrived last Friday with its crew of seven astronauts, are being used to keep the space station in its proper position while the computer problems are addressed, Jeffs said. Even if problems linger, he explained, the space station can remain in orbit for months without having to correct its flight attitude. A Russian Soyuz space capsule is always docked to the space station and can bring the crew safely to Earth in an emergency.

In a press release today from the Russian News & Information Agency Novosti, Nikolai Sevastyanov, the head of RKK Energia, a Russian space company, said the problem was caused Thursday by a "static discharge" that damaged power units for the station's computers during one of the shuttle crew's spacewalks. The news agency reported that Russian space authorities have contacted NASA to consider the possibility of running the affected oxygen, water and control systems from the U.S. segments of the space station.