He made three space shuttle flights, including the Atlantis mission in November 1994, which he commanded, to carry the third Atmospheric Laboratory for Applications and Science. He became manager of launch integration at the Kennedy Space Center in 1997. McMonagle was selected as an astronaut in 1987. In 1996, NASA assigned him the task of establishing a new Extravehicular Activity Project Office, which also involved him in upgrading spacesuit design. He logged 605 hours in space before leaving NASA.