Presentations given by the participants at the fourth annual summer conference of the NASA/USRA University Advanced Design Program are summarized. The study topics include potential space and aeronautics projects which could be undertaken during a 20 to 30 year period beginning with the Space Station Initial Operating Configuration (IOC) scheduled for the early to mid-1990's. This includes system design studies for both manned and unmanned endeavors; e.g., lunar launch and landing facilities and operations, variable artificial gravity facility for the Space Station, manned Mars aircraft and delivery system, long term space habitat, construction equipment for lunar bases, Mars oxygen production system, trans-Pacific high speed civil transport, V/STOL aircraft concepts, etc. Kennedy Space Center AEROSPACE ENGINEERING; AIRCRAFT DESIGN; MANNED ORBITAL LABORATORIES; ORBIT TRANSFER VEHICLES; SPACE HABITATS; SPACE STATIONS; SPACECRAFT DESIGN; ARTIFICIAL GRAVITY; HYPERSONIC VEHICLES; INTERPLANETARY FLIGHT; LUNAR BASES; LUNAR FLIGHT; MARS PROBES; ORBITAL ASSEMBLY; PLANETARY BASES; ROVING VEHICLES; SPACE EXPLORATION; SPACE PROBES; SUPERSONIC TRANSPORTS; TRANSATMOSPHERIC VEHICLES; V/STOL AIRCRAFT...