if it had been discovered before the flight. He was 51 years old, making him the oldest astronaut to fly in space at the time. Space Shuttle program Prior to the ASTP flight, Slayton was assigned by Chris Kraft to manage the Approach and Landing Tests (ALT) of the Space Shuttle program. The ALT program developed the tests for the Space Shuttle orbiter Enterprise, and modified several F-104 Starfighters and T-38 Talons to train the astronauts. While working on the Space Shuttle, he also assisted in developing the Shuttle Carrier Aircraft. The ALT program ended in late 1977 and Slayton agreed to manage the Space Shuttle's Orbital Flight Tests (OFT). During the selection of the Group 8 astronauts, Slayton advocated for fewer selections, with the expectation that two-man crews would fly the regular satellite deployment missions. He officially retired in 1980, but continued to serve in an advisory role for STS-1, and flew a T-38 chase plane during the landing of STS-2. He formally left NASA on February 27, 1982, and had flown 7,164 hours. Post-NASA career After his retirement from NASA, Slayton served as president of Space Services Inc., a Houston-based company earlier founded to develop rockets for small commercial payloads. He served as mission director for a rocket called the Conestoga, which was successfully launched on September 9, 1982, and was the world's first privately funded rocket to reach space. Slayton also became interested in aviation racing, and was President of International Formula One Pylon Air Racing and Director of Columbia Astronautics. He also served on the Department of Transportation's Commercial Space Advisory Committee. In 1991, Slayton began working with space historian Michael Cassutt to write his autobiography, titled Deke!: U.S. Manned Space from Mercury to the Shuttle, which was published in 1994, a year after his death. Slayton also co-wrote the 1994 book Moon Shot: The Inside Story of America's Race to the Moon with fellow astronaut Alan Shepard. Personal life Slayton married Marjorie "Marge" Lunney (1921–1989) on May 18, 1955, and they had one son, Kent Sherman, born April 8, 1957. They divorced in April 1978, and Slayton moved to a condominium near the Johnson Space Center. He married Bobbie Belle Jones (1945–2010), who also worked at NASA, in October 1983, and they remained married until his death. When Slayton was a test pilot, one of his pilot colleagues was also named Don. In order to