ESA astronaut Thomas Reiter of Germany (foreground), astronauts Piers J. Sellers, and Stephanie D. Wilson, all STS-121 mission specialists, participate in a training session in one of the full-scale trainers in the Space Vehicle Mockup Facility at the Johnson Space Center. Attired in training versions of the shuttle launch and entry suit, the three are seated on the middeck for an emergency egress training session. Crew trainers assisted the crew members.