The Mercury program was the United States's first successful manned spaceflight program. It ran from 1959 through 1963 with the goal of putting a man in orbit around the Earth. Early planning and research was carried out by NACA, while the program was officially carried out by the newly created NASA.
Mercury spacecraft were very small one-man craft; it was said that the Mercury spacecraft were not ridden, they were worn. The spacecraft had only attitude and reentry thrusters. They could not effect any orbital changes apart from the reentry burn. The spacecraft were designed to be totally controllable from the ground in the event that the space environment impaired the pilot's ability to function. Suborbital Mercury capsules used heat-sink beryllium heat shields, orbital ones used ablative shields.
The Mercury program used three boosters: Little Joe, Redstone, and Atlas. Little Joe and Redstone were used for suborbital flights, Atlas for orbital ones. The Atlas boosters required extra strengthening in order to handle the increased weight of the Mercury capsules beyond that of the nuclear warheads they were designed for. Little Joe was a solid-propellant booster designed specially for the Mercury program.
Mercury had seven prime astronauts, all former military test pilots, known as the "Mercury 7."
- Alan B. Shepard, Jr
- Virgil I. "Gus" Grissom
- John H. Glenn. Jr
- M. Scott Carpenter
- Walter M. Schirra, Jr
- L. Gordon Cooper, Jr
- Donald K. "Deke" Slayton
Six manned flights took place under the Mercury program.
- Mercury 6 (Mercury-Atlas-6) - 20 February 1962
- Mercury 7 (MA-7) - 24 May 1962
- Mercury 8 (MA-8) - 3 October 1962
- Mercury 9 (MA-9) - 15 May 1963
Cooper, Carpenter, Grissom, Shepard, Slayton, Schirra and Glenn have been immortalised in a song by English musician Adam Leonard.