Expedition 31 Preflight

Expedition 31 NASA flight engineer Joe Acaba, left, Soyuz Commander Gennady Padalka and flight engineer Sergei Revin, third from left, stand at attention before senior officials for their final qualification test in preparation for flight, Tuesday, April 24, 2012 at the Gagarin Cosmonaut Training Center in Star City, Russia. Acaba, Padalka and Revin are set to launch to the International Space Station May 15 from the Baikonur Cosmodrome in Kazakhstan. Photo Credit: (NASA/Carla Cioffi)