Power Control Unit Replacement

Astronaut John M. Grunsfeld, payload commander, works in tandem with astronaut Richard M. Linnehan, mission specialist, as the two devote their attention to the Power Control Unit replacement task on the giant Hubble Space Telescope (HST). Grunsfeld is attached to a foot restraint on the end of the Space Shuttle Columbia's Remote Manipulator System (RMS). This was the third of five Servicing Mission 3B spacewalks in March 2002 and the mission's second extravehicular activity (EVA) for the team of Grunsfeld and Linnehan.