Discovery astronauts Steve Bowen and Al Drew got an early start to their Feb. 28 spacewalk outside the International Space Station, kicking off the six- to seven-hour excursion at 10:46 a.m., EST, or about 30 minutes ahead of schedule.
Discovery spacewalkers Steve Bowen, left, and Al Drew, float outside the International Space Station’s airlock as their excursion gets under way. Photo Credit/NASA TV
Their first task is to extend a power cord jumper from the Unity module.The jumper will serve as a backup source of electricity for the station’s Tranquility module.The jumper outlet will be covered up on March 1, when the Discovery crew hoists a 21 foot-long equipment storage module from the shuttle’s payload bay and moves it to Unity with the station’s robot arm.
“You both look great out there,” radioed Discovery crewmate Nicolle Stott, who serves as the spacewalk coordinator on the STS-133 mission.
Discovery’s six astronauts docked with the station on Feb. 26, kicking off seven to eight days of assembly work and cargo exchanges.
The primary task for the spacewalk is the retrieval of a thermal control system pump that was left on the station’s inboard starboard solar power system truss following a July 31 failure.The device was replaced with a spare in early August by spacewalking station astronauts Doug Wheelock and Tracy Caldwell Dyson.
Drew and Bowen plan to move the 780-pound pump to a storage platform on the station’s airlock. There, it will await an opportunity to be returned to Earth over the summer aboard NASA’s hoped-for STS-135 mission, using Atlantis. Once on the ground, the pump will under go a failure analysis.
During a second spacewalk on March 2, Drew and Bowen plan to vent the pump of residual ammonia, a toxic coolant. Without a fully functioning thermal control system, the station cannot sustain a full time six person crew, or the many science experiments that are planned.