In this Feb. 20, 1962 photograph, Glenn smiles after the completion of his three-orbit mission into space. Although the mission was a success, it was nearly a disaster. During his re-entry into the Earth's atmosphere, a warning light went on that indicated his capsule's heat shield was loose. Though it was a false alarm, no one knew it and technicians on the ground decided to take action. They felt it was important to keep Friendship 7's retro-rocket pack attached rather than letting it go upon re-entry. The result was what Glenn saw as a "rear fireball," the pack burning away as he shot through the atmosphere.