Expedition 31 NASA NASA Flight Engineer Joe Acaba signs for his International Space Station Russian segment event simulation test card before senior officials at the Gagarin Cosmonaut Training Center, Monday, April 23, 2012 in Star City, Russia, while his fellow crew members Soyuz commander Gennady Padalka (left) and Sergei Revin look on. Acaba, Padalka and Revin are set to launch May 15 from the Baikonur Cosmodrome in their Soyuz TMA-04M spacecraft to the International Space Station. Photo Credit: (NASA/Carla Cioffi)