Mercury-Atlas 8 (
MA-8) was the fifth
United States manned space mission, part of
NASA's
Mercury program. Astronaut
Walter M. Schirra, Jr., orbited the Earth six times in the
Sigma 7 spacecraft on October 3, 1962, in a nine-hour flight focused mainly on technical evaluation rather than on scientific experimentation. This was the longest U.S. manned orbital flight yet achieved in the
Space Race, though well behind the several-day record set by the
Soviet Vostok 3 earlier in the year. It confirmed the Mercury spacecraft's durability ahead of the one-day
Mercury-Atlas 9 mission that followed in 1963.