JSC2007-E-18102 (9 April 2007) --- United Space Alliance (USA) crew trainer Adam Flagan (left) briefs astronaut Douglas H. Wheelock, STS-120 mission specialist, on the usage of a special pulley device, used to lower oneself from a trouble-plagued shuttle. The briefing came during an emergency egress training session in the Space Vehicle Mockup Facility at the Johnson Space Center. Wheelock is wearing a training version of his shuttle launch and entry suit.