April 9, 2010
Astronauts Complete First STS-131 Spacewalk
Discovery Mission Specialists Rick Mastracchio and Clayton Anderson wound up a 6-hour, 27-minute spacewalk at 6:58 a.m. CDT after helping move a new 1,700-pound ammonia tank from Discovery's cargo bay to a temporary parking place on the International Space Station. It was the first of three spacewalks planned during the STS-131 mission.
During the spacewalk, which began at 12:31 a.m., the two astronauts also retrieved an experiment from the Japanese Kibo Laboratory exposed facility and replaced a Rate Gyro Assembly on one of the truss segments.
The duo will complete the replacement of a depleted ammonia tank on the station during the mission's second and third spacewalks, scheduled for Sunday and Tuesday. Discovery will bring the depleted tank back to Earth to be refilled for subsequent return to the station. The ammonia is used for the station's cooling system.
Today the spacewalkers lifted the new tank from its carrier in the cargo bay and tilted it to enable the station's Canadarm2 operated by Pilot James P. Dutton Jr. and Mission Specialist Stephanie Wilson to grapple it for the move to the station. Mission Specialist Dorothy Metcalf-Lindenburger choreographed the spacewalk from inside, coaching the spacewalkers through their tasks.
The Kibo experiment, the Micro-Particles Capture/Space Environment Exposure Device, will be returned to Earth for analysis. The Rate Gyro Assembly is part of the station's navigation system.
The spacewalk was the fourth for both Mastracchio and Anderson. Mastracchio conducted three during the STS-118 mission, one of them with Anderson, who then was a long-duration crew member on the station as part of Expedition 15.
Today's spacewalk was the 141st dedicated to station assembly and maintenance totaling 879 hours, 43 minutes. Mastracchio now has completed four spacewalks totaling 24 hours, 40 minutes. Anderson also has conducted four spacewalks with a combined duration of 24 hours, 38 minutes.
Inside, crew members continued the transfer of equipment and supplies between Discovery and the station. The Multi-Purpose Logistics Module Leonardo, moved from the shuttle cargo bay and attached to the station Thursday, brought equipment, supplies and racks to the station, while additional cargo was carried on Discovery's middeck. Leonardo will bring home scientific experiments, equipment and trash from the station after it is returned to Discovery's cargo bay.
Discovery astronauts are scheduled to begin their sleep period about 12:20 p.m. and wake up at 8:21 p.m.
Image Caption: STS-131 Mission Specialist Rick Mastracchio exits the Quest airlock to begin the first of three spacewalks. Image credit: NASA TV
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