Walter Marty Schirra Jr. was an American naval aviator, test pilot, and NASA astronaut. In 1959, he became one of the original seven astronauts chosen for Project Mercury, which was the United States' first effort to put human beings into space. On October 3, 1962, he flew the six-orbit, nine-hour, Mercury-Atlas 8 mission, in a spacecraft he nicknamed Sigma 7. At the time of his mission in Sigma 7, Schirra became the fifth American and ninth human to travel into space. In the two-man Gemini program, he achieved the first space rendezvous, station-keeping his Gemini 6A spacecraft within 1 foot of the sister Gemini 7 spacecraft in December 1965. In October 1968, he commanded Apollo 7, an 11-day low Earth orbit shakedown test of the three-man Apollo Command/Service Module and the first crewed launch for the Apollo program.
He was the first astronaut to go into space three times, and the only astronaut to have flown in the Mercury, Gemini, and Apollo programs. In total, Schirra logged 295 hours and 15 minutes in space. After Apollo 7, he retired as a captain from the U.S.