Russian Mission Control Restores Contact With Failed ISS Computers

HOUSTON -- Russian flight controllers for the International Space Station (ISS) restored contact with a pair of vital computers aboard the orbital laboratory early Thursday after a major failure left the outpost dependent on U.S. systems and NASA?s shuttle Atlantis for attitude control.

NASA ISS flight director Holly Ridings said efforts to recover the failed computers overnight appeared to payoff as engineers reactivated communications with main systems in the station?s Russian-built Zvezda service module and the Zarya control module.

?It looks like they?ve made a lot of progress overnight,? Ridings said in a status report, adding that Russian Mission Control is now receiving telemetry from the station?s Russian segments. ?There?re some cleanup steps to do still, and some investigation.?

Efforts to bring the computers back up to full operations are underway.

An unexplained glitch shutdown primary Russian computers aboard the ISS early Wednesday, leaving it dependent on the station?s U.S. gyroscopes and thrusters aboard Atlantis for attitude control and other primary systems. The issue left mission managers contemplating a one-day extension to the space shuttle Atlantis crew?s already extended 13-day mission to give additional time to work through the glitch.

This morning, astronauts aboard Atlantis were given the go ahead by Mission Control here at NASA?s Johnson Space Center to power down non-essential shuttle systems should that one-day extension be required, but a final decision on the lengthening the mission has not been made, NASA said.

Atlantis? STS-117 astronauts are currently scheduled to return to Earth on June 21.

Ridings said that engineers are continuing to troubleshoot the Russian computer issues, but a number of positive steps occurred early Thursday. Russian ISS engineers speculated that glitch is a power problem, possibly related to the installation this week of new starboard solar arrays at the ISS, NASA said. ?

ISS Expedition 15 commander Fyodor Yurchikhin, a Russian cosmonaut, worked with flight controllers earlier today and reported that both of the computers under study were available and rebooting at about 7:02 a.m. EDT (1102 GMT). A few minutes later, power was restored to the station?s Zarya control module, NASA said.

The effort to restore communications with the computers did prompt a false fire alarm aboard the ISS, the second this week spawned by a computer glitch. But Ridings said that, as previously, there was no evidence an actual fire had occurred.

By 7:46 a.m. EDT (1146) a Soyuz spacecraft docked the ISS, which was switched to its own internal batteries late Wednesday as a power-saving measure, was once more drawing power from the ISS, NASA added.

?It has been a very positive sort of morning,? NASA spokesperson John Ira Petty told SPACE.com.

NASA is broadcasting the space shuttle Atlantis' STS-117 mission live on NASA TV. Click here for mission updates and SPACE.com's video feed.

• SPACE.com Video Interplayer: Space Station Power Up with STS-117
• STS-117 Power Play: Atlantis Shuttle Crew to Deliver ISS Solar Wings
• Complete Shuttle Mission Coverage