Gennady Padalka, the Station commander, and Mike Fincke, the NASA science officer and flight engineer, spent several days unloading about 2 1/2 tons of food, water, spare parts and supplies from the Progress 14 vehicle that docked to the aft end of the Zvezda Service Module at 8:55 a.m. CDT May 27.
Flight controllers later will transfer fuel from the Progress' tanks to those in the Russian modules of the Station.
Preparations for the upcoming spacewalk began in earnest Thursday, when the orbiting duo began configuring the Russian spacesuits they will use for the excursion, and charging batteries that will be used in their suits and cordless tools.
The spacewalk is scheduled for no earlier than June 15 Houston time. The status of preparations and planning for the spacewalk will be the subject of further review during regular Station management meetings next week. The goal 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 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 slated to be replaced when Space Shuttles resume flights next year.
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, American 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 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 slated 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.