Mastracchio has seen spaceflight from both sides—from space and from the ground. In the 1990s, he worked 17 shuttle flights as a guidance and navigation officer in Mission Control. Selected as an astronaut in 1993, he then flew three shuttle missions to the space station—including STS-106 in 2000, shortly before astronauts started living there permanently. Shown here during launch safety training in Florida, Mastracchio has made six spacewalks. He’ll begin his Expedition 38/39 tour in November 2013.