Shriver was selected as an astronaut by NASA in January 1978, participated in three space flights, and logged over 386 hours in space. In September 1982, he was selected as pilot of STS-10, the first Department of Defense mission for the Space Shuttle, but the mission was cancelled. He was pilot of STS-51-C, launched from Kennedy Space Center on January 24, 1985. He commanded a crew of five on his second mission, STS-31 which launched on April 24, 1990. This five-day flight deployed the Hubble Space Telescope. He also commanded mission STS-46 in 1992.