Head of Kazakhstan's National Space Agency, KazCosmos, and former cosmonaut Talgat Musabayev welcomes home Expedition 46 Commander Scott Kelly of NASA, left, and Russian cosmonauts Sergey Volkov, center, and Mikhail Kornienko at the Zhezkazgan Airport in Kazakhstan on Wednesday, March 2, 2016 (Kazakh time). Kelly and Kornienko completed an International Space Station record year-long mission to collect valuable data on the effect of long duration weightlessness on the human body that will be used to formulate a human mission to Mars. Volkov returned after spending six months on the station.