He has flown on five space shuttle missions since 1994, piloting two and commanding three, and has logged more than 1 250 hours in space. He was NASA's director of operations at the Gagarin Cosmonaut Training Centre in 1998. In 2000 he became manager of Shuttle Launch Integration at NASA's Kennedy Space Center and in 2003 became leader of the Space Shuttle Return to Flight Planning Team. He was assigned to a future flight postponed due to the 2003 Columbia space shuttle disaster. Halsell was selected as an astronaut in 1990 and retired from NASA in November 2006 to accept a position with ATK Launch Systems, Utah.