S90-46030 (Aug 1990) --- Astronaut Donald R. McMonagle (foreground) wears an extravehicular mobility unit (EMU) spacesuit as he prepares to be lowered into a 25-ft. deep pool at the Johnson Space Center's weightless environment training facility (WET-F). Astronaut Gregory J. Harbaugh, a fellow STS 39 mission specialist, shares the moveable platform with McMonagle and prepares to join him in the simulation of a contingency extravehicular activity (EVA) for the mission, scheduled for Discovery in the spring of 1991. A number of SCUBA-equipped divers assist in the training session.