Walheim and Schlegel during EVA 2

S122-E-008200 (13 Feb. 2008) --- European Space Agency (ESA) astronaut Hans Schlegel (top) and NASA astronaut Rex Walheim, both STS-122 mission specialists, participate in the mission's second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 45-minute spacewalk, among other tasks, Walheim and Schlegel worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.