Shuttle Crew Wraps Up Second Spacewalk at Station

Discovery astronauts wrapped up a six-hour, 14-minute spacewalk Wednesday, draining ammonia from an 800-pound pump module, working with the Canadian robotic device Dextre and completing a variety of other tasks.

The spacewalkers, Mission Specialists Steve Bowen and Alvin Drew, spent most of their time outside the International Space Station working separately. The start of the spacewalk, which began when the crew members switched their spacesuits to battery power at 10:42 a.m. EST, had been delayed 24 minutes to replace an O-ring on the lithium hydroxide canister of Bowen’s suit to fix a minor leak.

Bowen began by setting up the station’s Canadarm2, operated by STS-133 Mission Specialist Michael Barratt and Expedition 26 Commander Scott Kelly. He moved on to retrieve a lightweight adapter plate assembly, an experiment holder, from the outer end of the Columbus module and installed it in Discovery’s cargo bay for return to Earth.

Drew started with the relocated pump module for the station’s external ammonia cooling system, using a device he had installed on Monday’s spacewalk to vent the remaining coolant from the pump. He subsequently removed the device for return to the airlock.

Bowen spent about an hour working on Dextre, the Special Purpose Dexterous Manipulator, installing a camera light pan and tilt assembly and removing some insulation. Meanwhile, Drew removed and jettisoned insulation and repositioned a slipped sunshade on a nearby camera. He then installed a light on one of the small handcars, a crew and equipment translation aid. The astronauts use the carts, mounted on the station’s truss rails, to move objects.

After doing some cleanup, Bowen installed a camera lens cover on the arm’s elbow and relocated a foot restraint and a Russian cargo arm adapter. Drew moved on to the port truss to repair insulation on a radiator beam valve module. He also secured a grapple fixture stowage beam.