16th Space Shuttle Mission4th Flight of Discovery Crew:Karol J. Bobko, CommanderDonald E. Williams, PilotM. Rhea Seddon, Mission SpecialistS. David Griggs, Mission SpecialistJeffrey A. Hoffman, Mission SpecialistCharles D. Walker, Payload SpecialistU.S. Senator E.J. Garn, Payload Specialist U.S. Senator E.J. Garn (R-Utah) became the first civilian observer to fly aboard a Space Shuttle. Garn acted as a Payload Specialist and Congressional Observer and participated in a host of medical experiments during the flight.