John Glenn and NASA Administrator Charles Bolden share a laugh during the 50 Years of Americans in Orbit presentation for employees at NASA's Kennedy Space Center.

Mercury astronaut John Glenn, left, and NASA Administrator Charles Bolden share a laugh 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