STS-133 crew members Tim Kopra and Benjamin Drew

JSC2010-E-046459 (31 March 2010) --- NASA astronauts Tim Kopra and Alvin Drew (partially obscured), both STS-133 mission specialists, attired in training versions of their Extravehicular Mobility Unit (EMU) spacesuits, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Divers (out of frame) are in the water to assist the crew members in their rehearsal, intended to help prepare them for work on the exterior of the International Space Station.