June 29, 2004
International Space Station Status Report: SS04-017
Mission managers are giving the green light for crewmembers to try again Wednesday to repair a circuit breaker on the exterior of the International Space Station (ISS). The goal of tomorrow's spacewalk is restore power to a gyroscope that helps control the Station's orientation in orbit.
The Expedition 9 crew's first spacewalk was cut short last Thursday when flight controllers in Moscow noticed almost immediately an unexpectedly high rate of pressure loss in the primary oxygen bottle on Astronaut Mike Fincke's Russian spacesuit.
Based on analysis, testing and troubleshooting by the crew, managers concluded the excessive oxygen pressure drop was caused by an open oxygen flow switch on Fincke's suit. The switch was not fully seated into the normal flow position before the spacewalk started, causing an unexpectedly swift flow of oxygen from the primary oxygen bottle into Fincke's spacesuit. Russian technicians concluded that it was an isolated event and gave the crew approval to use the same suits for tomorrow's rescheduled spacewalk. The spacewalk procedures have been updated to provide additional crew verification steps to ensure the handle is properly positioned.
The two spacewalkers will restore power to Control Moment Gyroscope (CMG) #2 by replacing a Remote Power Controller Module (RPCM). CMG #2 was taken off line April 21 by the failure of a circuit breaker in the RPCM. Currently, because of the failure of CMG #1 about two years ago, the attitude of the Station is being controlled by the two remaining CMGs.
Coverage and commentary of the spacewalk will begin June 30 at 4:30 p.m. EDT. The spacewalk is scheduled to begin at 5:40 p.m. The excursion is expected to last up to six hours.
Because the spacewalk will be occurring at the same time the Cassini-Huygens spacecraft is arriving at Saturn, coverage of the spacewalk will be broadcast on AMC-9, Transponder 5, C-band, 85 degrees west longitude, vertical polarization, 3800 MHz with audio at 6.8 MHz. Cassini's mission will be seen on NASA Television's regular satellite channel, AMC-9, Transponder 9, 85 degrees west longitude, vertical polarization, 3880 MHz with audio at 6.8 MHz.
Both the spacewalk and Cassini programs will be broadcast live on the Internet at:
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:
- end -
text-only version of this release
NASA press releases and other information are available automatically by sending a blank e-mail message to
To unsubscribe from this mailing list, send a blank e-mail message to
Back to NASA Newsroom |
Back to NASA Homepage