After Scott Carpenter’s science heavy Mercury-Atlas 7 flight, Nasa’s next mission would concentrate on the technical and engineering aspects of space travel. Mercury Atlas 8 became the third manned orbital flight of the Mercury program. The pilot selected was Walter M. Schirra, Jr., but most people called him Wally…
The primary objectives of the Surveyor program, were to support the Apollo landings by: (1) developing and validating the technology for landing softly on the Moon; (2) providing data on the compatibility of the Apollo design with conditions encountered on the lunar surface; and (3) adding to the scientific knowledge of the Moon.
A total of five Lunar Orbiter missions were launched by the US in 1966 through 1967. The purpose of the lunar orbiter series was to photograph the moon’s surface for selection and verification of safe landing sites for the Surveyor and Apollo missions.
Mercury-Redstone 4 was the fourth mission in the Mercury-Redstone series and the second U.S. manned suborbital spaceflight. The mission was essentially a repeat of Alan Shepard’s Freedom 7 flight. So why was it necessary to launch another sub-orbital mission? Why not proceed with an orbital flight to match the Soviet Vostok 1? Among other things the U.S. needed more space experience to corroborate the “Man-in-Space” concept. Also the Redstone was the only booster NASA had that was approved for manned launches. The Atlas booster was available but not ready. Atlas was capable of putting a Mercury Capsule into orbit, but it had been launched three times with unmanned capsules, and it had exploded on 2 of the 3 attempts.