STS-135 crew members Rex Walheim and Sandra Magnus

JSC2011-E-017413 (16 Feb. 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, participates in an extravehicular activity (EVA) training session in the Partial Gravity Simulator (POGO) test area in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. NASA astronaut Sandy Magnus, mission specialist, looks on. Photo credit: NASA or National Aeronautics and Space Administration