The maiden voyage of space shuttle Challenger began with liftoff at 1:30 p.m. on April 4, 1983 from pad 39A at Kennedy Space Center. Commander Paul Weitz, pilot Karol Bobko and mission specialists Don Peterson and Story Musgrave deployed NASA's Tracking and Data Relay Satellite-A with its attached Inertial Upper Stage. The mission specialists conducted the first spacewalk of the shuttle program.