Kennedy Space Center, FL - Space Shuttle astronauts being briefed on the emergency pad escape system are (left to right) prime crew Pilot Bob Crippen, backup crew member Richard Truly, prime crew Commander John Young and backup crew member Joe Engle.  The slidewire system provides a quick escape from upper launch pad platform in case of a serious emergency. The flight crews wore the spacesuits and other equipment to be worn during a mission, but sandbags were used to duplicate the weight of riders in the slidewire baskets during the training.