The six crew members of the International Space Station's Expedition 31 gather inside the Dragon cargo spacecraft for a group photo just prior to its departure and return to Earth on May 29, 2012. Pictured clockwise (from lower left) are Russian cosmonauts Gennady Padalka and Sergei Revin, European Space Agency astronaut André Kuipers, all flight engineers; Russian cosmonaut Oleg Kononenko, commander; NASA astronauts Don Pettit and Joe Acaba, both flight engineers. Designed from the start to transport crew, SpaceX's Dragon has already met numerous human spaceflight requirements in order to berth with and operate as part of the international orbiting laboratory. Photo: NASA ISS031-E-078299