He piloted two flights aboard the space shuttle Discovery in January 1992 and April 1993. In March 1995 he commanded the Endeavour flight on the second mission of the Astro Observatory, during which he established a space shuttle duration record of 17 days. He was then assigned to NASA headquarters in Washington, DC, as deputy associate administrator for Space Operations. He returned to the Astronaut Office in 1998 and retired from NASA in 2001.
Oswald was selected as an astronaut in 1985. He served as deputy associate administrator for Space Operations at NASA headquarters in Washington, DC, 1995–8, retiring from NASA in 2000.