STS-135 crew during Space Station Mockup Training

JSC2011-E-021703 (25 Feb. 2011) --- NASA astronaut Chris Ferguson (center), STS-135 commander; along with astronauts Rex Walheim and Sandy Magnus, both mission specialists, participate in a training session in a space station mock-up in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration