ISS STATUS REPORT: SS04-013

The crewmembers aboard the International Space Station (ISS) are busy getting ready for their spacewalk this month to replace a faulty circuit breaker. They also spent this week unpacking a Russian resupply spacecraft.

Gennady Padalka, Expedition 9 commander, and Mike Fincke, the NASA ISS science officer and flight engineer, spent several days unloading about 2.5 tons of food, water, spare parts and supplies. The supplies were on board the Progress spacecraft that docked to the aft end of the Zvezda Service Module at 9:55 a.m. EDT May 27. Flight controllers will transfer fuel from the Progress tanks to the ISS Russian modules.

Preparations for the upcoming spacewalk (EVA) began in earnest yesterday. The crew began configuring the Russian spacesuits they’ll use for the excursion, charging suit and cordless tools’ batteries.

The spacewalk is scheduled for no earlier than June 15. The status of preparations and planning for the spacewalk will be reviewed during regular Station management meetings next week. The goal of the EVA is to replace a power controller that failed April 21, resulting in the temporary loss of one of three operational Control Moment Gyros (CMGs) that govern the orientation of the orbiting complex.

Although the two functioning CMGs are sufficient to control the Station’s attitude without the use of Russian chemical thrusters, Station managers and flight controllers would like to have the additional backup CMG available for attitude control during the expedition’s two scheduled spacewalks later this summer. A fourth CMG failed two years ago and is scheduled to be replaced when Space Shuttles resume flights.

This will be the first bilaterally coordinated spacewalk in history, with flight controllers in Houston and Moscow taking turns as the primary ground support team. Russian ground experts will coordinate as Padalka and Fincke don their Russian Orlan spacesuits, exit the Pirs airlock and use the Strela cargo crane to travel to the U.S.-built section of the Station.

Once there, U.S. flight controllers will assume primary responsibility for the replacement of the faulty Remote Power Control Module (RPCM) and assist with routing power through the new RPCM to the gyroscope. After power is restored to the CMG, Houston flight controllers will assist the spacewalkers in their hand-over-hand return to the Russian crane and pass responsibility back to the Russian ground team.

Last week, Fincke and Padalka took turns moving the Station’s Canadarm2 robotic arm to a position along the S0 Truss for camera views of the spacewalk worksite. Late next week, they are scheduled to climb into their spacesuits for a dress rehearsal of the suit up and systems checkout that will clear the way for the spacewalk.

Padalka and Fincke also conducted Russian hand movement studies as part of a series of biomedical experiments and routine housekeeping tasks that filled up the remainder of their workdays.

Information about crew activities on the Space Station, future launch dates, and Station sighting opportunities from Earth, is available on the Internet at:

http://spaceflight.nasa.gov/

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:

http://scipoc.msfc.nasa.gov/