CAPE CANAVERAL, Fla. -- From left to right, Center Director Bob Cabana, Mercury astronauts Scott Carpenter and John Glenn, and NASA Administrator Charles Bolden share the stage during the "50 Years of Americans in Orbit" presentation for employees at NASA's Kennedy Space Center in Florida. This year marks 50 years since Glenn and Carpenter became the first two Americans to orbit Earth. Photo credit: NASA/Kim Shiflett KSC-2012-1403