Mercury astronauts Scott Carpenter and John Glenn pause for a handshake at the conclusion of the 50 Years of Americans in Orbit presentation.

Mercury astronauts Scott Carpenter and John Glenn pause for a handshake at the conclusion of the "50 Years of Americans in Orbit" presentation for employees at NASA's Kennedy Space Center in Florida. NASA Administrator Charles Bolden and Center Director Bob Cabana joined Carpenter and Glenn for the event.

This year marks 50 years since Glenn and Carpenter became the first two Americans to orbit Earth. Photo credit: NASA/Kim Shiflett