US astronaut. He joined the Johnson Space Center in 1983 and held several positions before being selected as an astronaut in 1998. He headed the trajectory design team as flight design manager for the Galileo mission, launched in 1989, and the Gamma-Ray Observatory, launched by the space shuttle Atlantis in 1991. He became chief of the flight design branch in 1993 and manager of the Emergency Operations Center in 1996.
Subjects: Astronomy and Astrophysics.