DiscoveryThe first Space Shuttle launch in over two years since the Challenger accident, Discovery lifts off on a flight to test improved safety systems and procedures. The shuttle’s major payload is the second TDRS (Tracking & Data Relay Satellite) launched by NASA (an identical satellite was lost in the Challenger explosion in 1986), as well as numerous smaller experiments. Problems with Discovery’s environmental system cause the crew cabin to be warmer than usual. Discovery’s crew for this flight consists of Commander Fred Hauck, Pilot Richard Covey, and mission specialists John Lounge, George Nelson, and David Hilmers.