20th Space Shuttle Mission6th Flight of Discovery Crew:Joseph H. Engle, CommanderRichard O. Covey, PilotJames D.A. van Hoften, Mission SpecialistJohn M. Lounge, Mission SpecialistWilliam F. Fisher, Mission Specialist Three communications satellites were deployed during the mission. These included ASC-1 for American Satellite Company, AUSSAT-1 for Australia, both of which employed PAM-D solid rocket motors. SYNCOM-IV-4 (also called LEASAT-4) reached geosynchronous orbit but failed to operate.