Stefanshyn-Piper and Bowen Complete First Spacewalk

STS-126 Status Report #09

Astronauts Heidemarie Stefanyshyn-Piper and Steve Bowen completed the first of four spacewalks scheduled for Endeavour’s mission to the International Space Station today. The spacewalk was the 115th in support of ISS construction. Piper and Bowen began the spacewalk at 12:09 p.m. CST and ended it at 7:01 p.m.

They spent six hours and 52 minutes outside the station working on several tasks, including removing a depleted nitrogen tank from a stowage platform on the outside of the complex and moving it into Endeavour’s cargo bay. They also moved a flex hose rotary coupler from the shuttle to the station stowage platform, as well as removing some insulation blankets from the common berthing mechanism on the Kibo laboratory.

The majority of the spacewalk was spent focusing on one of the station’s Solar Alpha Rotary Joints (SARJ). These joints are the large, circular devices that allow the complex’s solar arrays to automatically rotate and track the sun as the station orbits the Earth. Piper and Bowen worked to clean and lubricate part of the joint and to remove two of the joint’s 12 trundle bearing assemblies.

This work will continue during the rest of the mission’s scheduled spacewalks. About halfway into the spacewalk, one of the grease guns that Piper was preparing to use on the SARJ released some Braycote grease into her crew lock bag, which is the tool bag the spacewalkers use during their activities. As she was cleaning the inside of the bag, it drifted away from her and toward the aft and starboard portion of the International Space Station. Inside the bag were two grease guns, scrapers, several wipes and tethers and some tool caddies. Piper and Bowen spent the remainder of the spacewalk sharing a duplicate set of tools from the other crew lock bag they had with them.

The next spacewalk of the mission will take place on Thursday, which will be the 10th anniversary of the launch of the first element of the station, the Zarya module. Inside the station, Endeavour’s crew and the Expedition 18 crew worked to continue moving items out of the Leonardo Multipurpose Logistics Module (MPLM) that was docked with the station yesterday.

The crew is ahead of its transfer timeline and focused on moving two water recovery system (WRS) racks and one of the new sleep stations into the ISS. The transfer tasks will continue on throughout Endeavour’s visit to the station, when the MPLM will be undocked and placed back into Endeavour’s payload bay for return to Earth.

STS-126 Crew Portrait