Second STS-122 spacewalk ends at the ISS

HOUSTON, Feb. 13 (UPI) -- Space shuttle Atlantis astronauts conducted a six-hour, 45-minute spacewalk Wednesday at the International Space Station, installing a nitrogen tank assembly.

National Aeronautics and Space Administration astronaut Rex Walheim and European Space Agency astronaut Hans Schlegel completed the spacewalk's prime objective -- removal of an expended nitrogen tank assembly and the installation of a new one. The tank is part of the space station's cooling system.

Walheim and Schlegel began the second of STS-122's three scheduled spacewalks at 9:27 a.m. EST Wednesday. During the afternoon, moving well ahead of the scheduled pace, the astronauts also attended to miscellaneous chores, such as inspecting damaged micrometeor debris shields on the exterior of the space station's Destiny laboratory.

The spacewalk officially ended at 4:12 p.m. EST when the astronauts entered the airlock and re-pressurization started, NASA controllers in Houston said.

Astronaut Stanley Love will join Walheim for STS-122's third spacewalk, scheduled to begin Friday at 8:35 a.m. EST. They will install two payloads on the exterior of the European Space Agency's Columbus laboratory: SOLAR, an observatory to monitor the sun; and the European Technology Exposure Facility that will carry eight experiments requiring exposure to the space environment.