Space Shuttle Endeavour's Mission To The International Space Station

IN SPACE - AUGUST 11: In this handout photo provided by NASA, Astronaut Rick Mastracchio, STS-118 mission specialist, participates in the mission's first planned session of extravehicular activity as construction continues on the International Space Station August 11, 2007 in Space. During the 6-hour, 17-minute spacewalk Mastracchio and Williams attached the Starboard 5 (S5) segment of the station's truss, retracted the forward heat-rejecting radiator from the station's Port 6 (P6) truss, and performed several get-ahead tasks. (Photo by NASA via Getty Images)