Space-suited astronaut Story Musgrave in training for the repair of the Hubble Space Telescope (HST) during Shuttle Mission STS-61. To simulate working under zero gravity in orbit, the astronauts train inside a deep pool of water known as WET-F (Weightless Environment Training Facility). Here, Musgrave is practicing the use of a power tool used to attach the Wide Field & Planetary Camera (WFPC) replacement to the body of the telescope. The platform upon which Musgrave is standing is fixed to the end of a Remote Manipulating System (RMS) arm, identical to those used on Shuttle vehicles in orbit. STS-61 is scheduled for flight in December 1993.