S134-E-009587 (27 May 2011) --- NASA astronaut Michael Fincke participates in the mission's fourth session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the seven-hour, 24-minute spacewalk, Fincke and astronaut Greg Chamitoff (out of frame), both STS-134 mission specialists, completed the primary objectives for the spacewalk, including stowing the 50-foot-long boom and adding a power and data grapple fixture to make it the Enhanced International Space Station Boom Assembly, available to extend the reach of the space station's robotic arm. Photo credit: NASA