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.
advertisement
