Astronaut Janet L. Kavandi, mission specialist, participates in an underwater simulation of a contingency space walk during a training session at the Johnson Space Center (JSC). Kavandi, wearing a training version of the extravehicular mobility unit (EMU) space suit, weighted so as to achieve a neutrally buoyant state in the deep pool of JSC's Neutral Buoyancy Laboratory (NBL), was joined by astronaut Franklin R. Chang-Diaz (out of frame) in the simulation. The NBL is part of JSC's Sonny Carter Training Center, first used by assigned astronauts last year.