NASA Space Station Status Report 2 Jul 2004
The International Space Station (ISS) is again
operating with three of its four control gyroscopes, thanks
to this week’s spacewalk by the Expedition 9 crew. Flight
controllers today placed Control Moment Gyroscope #2 (CMG
#2) back in full operation along with CMGs #3 and #4. The
three CMGs are now controlling the Station’s attitude and
orientation.
During a five-hour, 40-minute spacewalk Wednesday night,
Expedition 9 Commander Gennady Padalka and NASA ISS Science
Officer Mike Fincke successfully replaced a failed circuit
breaker that provides power to CMG #2.
After a slow ramping up of speed over several hours, the
newly restored gyroscope reached its normal peak spin rate
of 6,600 revolutions per minute yesterday afternoon.
Engineers performed further testing overnight to monitor the
gyroscope’s operation before putting it back in operation
this morning.
Padalka and Fincke spent today working on post-spacewalk
clean-up tasks, including putting away some of the tools
they used during their repair job and conducting a follow-up
conference with spacewalk specialists.
Tomorrow the crewmembers will be back to a normal sleep
schedule as they begin a three-day weekend to celebrate the
Independence Day holiday. They’ll finish up spacewalk close-
out tasks next week and work on science experiments, such as
the Advanced Diagnostic Ultrasound in Microgravity.
Yesterday, the crew had a short, off-duty day. Also, Russian
flight controllers used air from the Progress cargo
spacecraft’s supply tanks to partially repressurize the
orbiting laboratory, replacing air that had been vented
overboard to allow the airlock to be opened for Wednesday’s
spacewalk.
The ISS has four CMGs that are designed to control which way
the Station is pointed as it
orbits the Earth. CMG #1 failed two years ago and will be
replaced during the next Space Shuttle mission. CMG #2 was
taken off line April 21, but was restored after the
spacewalk. The Station’s two other CMGs have been working
normally.
For information about NASA and agency missions on the
Internet, visit:
Information about crew activities on the Space Station,
future launch dates, and Station sighting opportunities from
Earth, is available on the Internet at:
Details about Station science operations are available on an
Internet site administered by the Payload Operations Center
at NASA’s Marshall Space Flight Center in Huntsville, Ala.,
at:
