NASA - National Aeronautics and Space Administration

JSC2011-E-054033 (13 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, attired in a training version of her Extravehicular Mobility Unit (EMU) spacesuit, prepares for a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Astronaut Chris Ferguson, commander, assisted Magnus. Photo credit: NASA

JSC2011-E-054034 (13 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, attired in a training version of her Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054047 (13 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, gets help donning a training version of her Extravehicular Mobility Unit (EMU) spacesuit in preparation for a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054048 (13 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, attired in a training version of her Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054050 (13 June 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, gets help donning a training version of his Extravehicular Mobility Unit (EMU) spacesuit in preparation for a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054053 (13 June 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, gets help donning a training version of his Extravehicular Mobility Unit (EMU) spacesuit in preparation for a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054058 (13 June 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, attired in a training version of his Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054065 (13 June 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, attired in a training version of his Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054067 (13 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, attired in a training version of her Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Photo credit: NASA

JSC2011-E-054076 (13 June 2011) --- NASA astronauts Sandy Magnus and Rex Walheim (mostly obscured), both STS-135 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 are in the water to assist Magnus and Walheim in their rehearsal. Photo credit: NASA