NASA - National Aeronautics and Space Administration

JSC2011-E-026880 (11 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an Extravehicular Mobility Unit (EMU) spacesuit fit check in the Space Station Airlock Test Article (SSATA) in the Crew Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-026885 (11 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an Extravehicular Mobility Unit (EMU) spacesuit fit check in the Space Station Airlock Test Article (SSATA) in the Crew Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-026887 (11 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an Extravehicular Mobility Unit (EMU) spacesuit fit check in the Space Station Airlock Test Article (SSATA) in the Crew Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-026896 (11 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an Extravehicular Mobility Unit (EMU) spacesuit fit check in the Space Station Airlock Test Article (SSATA) in the Crew Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-026902 (11 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an Extravehicular Mobility Unit (EMU) spacesuit fit check in the Space Station Airlock Test Article (SSATA) in the Crew Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-028122 (23 March 2011) --- NASA astronauts Doug Hurley, STS-135 pilot; and Sandy Magnus (foreground), mission specialist, participate in an exercise in the systems engineering simulator in the Avionics Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-028124 (23 March 2011) --- News media representatives and NASA personnel are pictured during an STS-135 media day event in the Avionics Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-028125 (23 March 2011) --- News media representatives and NASA personnel are pictured during an STS-135 media day event in the Avionics Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-028126 (23 March 2011) --- NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; and Sandy Magnus, mission specialist, are pictured during an STS-135 media day event in the Avionics Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

JSC2011-E-028127 (23 March 2011) --- NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; and Sandy Magnus, mission specialist; along with news media representatives and NASA personnel are pictured during an STS-135 media day event in the Avionics Systems Laboratory at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration