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Man-In-Space-Soonest (MISS) was a United States Air Force (USAF) program to put a man into outer space before the Soviet Union. It consisted of orbiting a ballistic capsule with instruments, and then progressing to primates and finally man. The Thor-Vanguard, Thor with a fluorine upper stage, and a Titan with added fluorine second and third stages were considered as launch vehicles.
The program was cancelled on August 1, 1958, and was replaced by NASA's Project Mercury. Only two men from the program would actually reach outer space. The first, Joseph A. Walker, did so two or three times (depending on the definition of the space border) in X-15 rocket plane tests in 1963. The other, Neil Armstrong, became a NASA astronaut in 1962, flew on Gemini 8 in 1966, and in 1969 on Apollo 11 becoming the first person to walk on the Moon.
MISS would have used a Thor booster, then later an Atlas, to launch a single-man spacecraft into orbit. On June 25, 1958, the Air Force announced the following nine men selected to be astronauts for the program: