STS-119 crew members Steve Swanson and Joe Acaba

JSC2008-E-041623 (20 May 2008) --- Astronauts Joseph M. Acaba and Steven R. Swanson (partially visible at upper left corner), both STS-119 mission specialists, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Acaba and Swanson are attired in training versions of their Extravehicular Mobility Unit (EMU) spacesuits. Divers 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.