Scott Carpenter left and John Glenn sit in front of a capsule from the Mercury program on display at the Kennedy Space Center Visitor Complex.

Mercury astronauts Scott Carpenter, left, and John Glenn sit in front of a capsule from the Mercury program on display at the Kennedy Space Center Visitor Complex in Florida. The two astronauts, part of the original class of seven astronauts chosen by NASA, were taking part in events 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 Carpenter, Walter Schirra and Gordon Cooper. Their fellow Mercury astronauts Alan Shepard and Virgil "Gus" Grissom flew earlier suborbital flights. Deke Slayton was grounded by a medical condition until the Apollo-Soyuz Test Project in 1975. Photo credit: NASA/Kim Shiflett