The Spacelab 2 science research mission was launched aboard Challenger at 5:00 p.m. on July 29, 1985. The crew was led by commander Gordon Fullerton, with pilot Roy Bridges, mission specialists Story Musgrave, Anthony England and Karl Henize and payload specialists Loren Action and John-David Bartoe. A premature shutdown of one of the three main engines caused the first abort-to-orbit for a space shuttle.