Karol Bobko, who commanded STS-51, the first flight of space shuttle Atlantis, background, speaks at the signing ceremony, Friday, Nov. 2, 2012, in Cape Canaveral, Fla. The spacecraft traveled 125,935,769 miles during 33 spaceflights, including 12 missions to the International Space Station. Its final flight, STS-135, closed out the Space Shuttle Program era with a landing on July 21, 2011. Photo Credit: (NASA/Bill Ingalls)