Expedition 31 crew members Joe Acaba, left, Commander Gennady Padalka and Sergei Revin, right, wave farewell as they depart the Cosmonaut Hotel on Tuesday, May 15, 2012 in Baikonur, Kazakhstan. The Soyuz spacecraft with Expedition 31 Soyuz Commander Gennady Padalka, Flight Engineer Sergei Revin, and NASA Flight Engineer Joe Acaba aboard launched at 9:01 a.m. Kazakhstan time on Tuesday, May 15. Photo Credit (NASA/Victor Zelenstov)