NASA Kennedy Space Center Bob Cabana talks to a guest about the Mercury Project's Atlas rocket in the Vehicle Assembly Building.

NASA Kennedy Space Center Bob Cabana talks to a guest about the Mercury Project's Atlas rocket in the Vehicle Assembly Building. At the space center in Florida, Cabana is helping John Glenn mark the 50th anniversary of being the first American astronaut to orbit the Earth inside the NASA Mercury Project's Friendship 7 capsule on Feb. 20, 1962. Glenn later returned to space in October 1998 as a payload specialist aboard space shuttle Discovery's STS-95 mission.

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: Cory Huston