JSC2001-E-24453 (8 August 2001) --- Astronaut Richard M. Linnehan, STS-109 mission specialist, uses virtual reality hardware at the Johnson Space Center (JSC) to rehearse some of his duties on the upcoming STS-109 mission, NASA�s fourth servicing visit to the Hubble Space Telescope (HST). He will join six other astronauts for the servicing mission, scheduled for February 2002.