Details of the Spacewalks the Expedition 38 Crew will Conduct to Repair the International Space Station.

"Lead U.S. Spacewalk Officer Allison Bolinger discusses the details of the three spacewalks the Expedition 38 crew will conduct to replace a faulty pump module on the International Space Station. Flight Engineers Rick Mastracchio and Mike Hopkins will venture out of the station's Quest airlock on Dec. 21, 23 and 25 to remove a pump module that has a failed valve and replace it with an existing spare that is stored on an external stowage platform. The pump is associated with one of the station's two external cooling loops, which circulate ammonia outside the station to keep both internal and external equipment cool. "