Her two space shuttle flights were as the pilot of the Microgravity Science Laboratory in April and July 1997, both aboard Columbia. The first flight was aborted after more than 95 hours because of problems with a fuel cell. The second lasted for more than 376 hours and involved experiments on materials and combustion in microgravity. Still-Kilrain was selected as an astronaut in 1995. After her flights, she was a specialist for the space shuttle in the Office of Legislative Affairs at NASA's headquarters in Washington, DC. She retired from NASA in December 2002 to return to the US Navy.