US EVA 16 EMU Prep

ISS024-E-011673 (11 Aug. 2010) --- NASA astronaut Tracy Caldwell Dyson, Expedition 24 flight engineer, attired in her Extravehicular Mobility Unit (EMU) spacesuit, is pictured in the Quest airlock of the International Space Station as the second of three planned spacewalks to remove and replace an ammonia pump module that failed July 31 draws to a close. NASA astronaut Shannon Walker and Russian cosmonaut Fyodor Yurchikhin, both flight engineers, assist Caldwell Dyson with the doffing of her spacesuit.