Gregory Errol Chamitoff is an engineer and NASA astronaut. He was assigned to Expedition 17 and flew to the International Space Station on STS-124, launching 31 May 2008. He was in space for 6 months, joining Expedition 18 after Expedition 17 left the station. He returned to Earth on the 30th of November 2008 aboard STS-126. Chamitoff served as a mission specialist on the STS-134 mission, which was the last flight of Space Shuttle Endeavour which delivered the Alpha Magnetic Spectrometer to the ISS.