Astronaut Exit into Space - Astronauts extravehicular activity - Astronaut Exit Rick Mastracchio (left) and...

Astronaut Exit into Space - Astronauts extravehicular activity - Astronaut Exit Rick Mastracchio (left) and Clayton Anderson into Space. Maintenance of the International Space Station (ISS). 11 April 2010. NASA astronauts Rick Mastracchio (left) and Clayton Anderson, both STS - 131 mission specialists, participate in the mission's second session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the seven - hour, 26 - minute spacewalk, Mastracchio and Anderson unhooked and removed the depleted ammonia tank and installed a 1,700 - pound ammonia tank on the station's Starboard 1 truss, completing the second of a three - spacewalk coolant tank replacement process. April 11 2010