Space Station Fires Russian Thrusters in Test

HOUSTON -- The International Space Station (ISS) fired up its Russian thrusters Monday during a vital test to verify the health of navigation and control computers that failed last week.

The test, which ended at 12:09 p.m. EDT (1609 GMT) and appeared to go smoothly, is a critical step for mission managers deciding whether the space shuttle Atlantis currently docked at the station will depart with its seven-astronaut crew on Tuesday as planned.

?It seemed successful,? NASA spokesperson Bill Jeffs told SPACE.com, adding that mission managers will meet later today to discuss the results.

During the test, ISS flight controllers handed control of the station?s orientation from the shuttle Atlantis to the Russian thrusters governed by a navigation and guidance - or terminal - computer inside the orbital laboratory?s Russian-built segment.

The Russian navigation system maintained attitude control of the ISS, and then transferred control of the thrusters to U.S. guidance systems which later shut down the thrusters and brought up U.S. control moment gyroscopes to take over. Monday?s test began at 10:34 a.m. EDT (1434 GMT).

?That?s a big step in our checkout of the computers to make sure everything is working correctly,? ISS flight director Holly Ridings said early Monday before the test.

Shuttle and ISS mission manager will go over the data from the test and make a final decision on whether the Atlantis astronauts will leave Tuesday on schedule or remain docked an extra day.

Atlantis? STS-117 crew, commanded by veteran astronaut Rick Sturckow, is due to shut the hatch between their shuttle and the ISS at 6:23 p.m. EDT (2223 GMT) today if the station computer test checks out.

The astronauts successfully delivered new starboard trusses and solar arrays to the ISS, furled an older solar wing and ferried a new crewmember to join the station?s Expedition 15 crew. ?

The Russian terminal computer, along with two others and three command and control computers, failed last week, leaving the station without the use of its primary Elektron oxygen generator and other environmental control systems.

The shutdown also left the ISS dependent on U.S.-built gyroscopes and thrusters aboard Atlantis for attitude control. By Saturday, however, Russian engineers and cosmonauts revived all six computers and all environmental systems aside from the Elektron oxygen generator, which is offline as planned while the station draws on supplies aboard a docked cargo ship, NASA said.

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
• IMAGES: Atlantis Shuttle?s STS-117 Launch Day
• Complete Shuttle Mission Coverage