STS-120 Astronauts Scott Parazynski and Doug Wheelock at NBL

JSC2007-E-06550 (2 Feb. 2007) --- Astronauts Douglas H. Wheelock and Scott E. Parazynski (partially obscured), both STS-120 mission specialists, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center. Wheelock and Parazynski are attired in training versions of the Extravehicular Mobility Unit (EMU) spacesuit. SCUBA-equipped divers (out of frame) are in the water to assist the crewmembers in their rehearsal, intended to help prepare them for work on the exterior of the International Space Station.