US astronaut. He flew on the Atlantis flight in April 2002 to the International Space Station, making two space walks to prepare the station for future space walks. He has logged over 259 days in space and over 14 hours of space walks. Walheim was a flight controller and operations engineer at NASA's Johnson Space Center from 1986 to 1989. He was selected as an astronaut in 1996.
Subjects: Astronomy and Astrophysics.