Selfie of Alexander Gerst during U.S. EVA #27 * European Space Agency astronaut Alexander Gerst, Expedition 41 flight engineer, participates in a session of extravehicular activity (EVA) as work continues on the International Space Station. During the six-hour, 13-minute spacewalk, Gerst and NASA astronaut Reid Wiseman (out of frame), flight engineer, worked outside the space station's Quest airlock relocating a failed cooling pump to external stowage and installing gear that provides back up power to external robotics equipment.