Former Mercury astronaut Scott Carpenter left and former Kennedy Space Center directors celebrating 50 years of Americans in orbit.

Former Mercury astronaut Scott Carpenter, left, and former Kennedy Space Center directors Jay Honeycutt, Bob Crippen, Forrest McCartney and Roy Bridges listen during a luncheon Feb. 17, 2012, celebrating 50 years of Americans in orbit, an era which began with Glenn's Mercury mission MA-6, on Feb. 20, 1962.
Glenn's launch aboard an Atlas rocket took with it the hopes of an entire nation and ushered in a new era of space travel that eventually led to Americans walking on the moon by the end of the 1960s. Glenn soon was followed into orbit by Scott Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton, a member of NASA's original Mercury 7 astronauts, was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett