Spacewalkers Walheim and Schlegel Install New Nitrogen Tank Assembly

Astronauts Rex Walheim and Hans Schlegel completed the second of STS-122’s three scheduled spacewalks at 4:12 p.m. EST. The excursion lasted six hours and 45 minutes.

The spacewalkers completed the removal of an expended Nitrogen Tank Assembly (NTA) and the installation of a new one on the P1 truss. The tank is part of the orbital outpost’s cooling system.

With the help of the station’s robotic arm, the spacewalkers moved the new NTA from its position in space shuttle Atlantis’ payload bay. They temporarily stowed it on a Crew and Equipment Translation Aid cart while they removed the expended tank. With the new NTA installed, the old tank was transferred to the orbiter’s payload bay for return to Earth.

Because they finished their primary tasks early, the spacewalkers were able to install thermal covers on the trunnion pins on the European Space Agency’s Columbus laboratory. They also inspected and adjusted the U.S. Destiny laboratory's orbital debris shields.

Mission Specialist Stanley Love will join Walheim for STS-122’s third spacewalk on Friday at 8:35 a.m. They will install two payloads on the exterior of the 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.

The space shuttle Mission Management Team, at the request of the International Space Station Program, has extended the STS-122 mission to 13 days. Atlantis will undock from the space station on Monday, Feb. 18, and land at 8:59 a.m. Wednesday, Feb. 20, at Kennedy Space Center, Fla.

Source: NASA