The preliminary design of a heavy lift launch vehicle called Shuttle - C is currently under-way to provide over 100,000 lbs (45,455 kg) pay load capability to a low earth orbit of 220 nautical miles (408 km) in the early 1990's. Although derived from the Space Shuttle (Space Transportation System or STS) concept using the same elements of External Tank (ET), Solid Rocket Boosters (SRB's), and main engines (SSME's), the Shuttle - C vehicle is an expendable, unmanned launch vehicle. The program ground rules require a minimum of engineering design, development, test and evaluation (DDT&E) cost, and a compressed development schedule to meet near term mission requirements. The Shuttle - C missions encompass a wide variety of payload types such as suborbital deployment of planetary vehicles, earth orbiting platforms, Centaur missions to Geosynchronous Orbit (GEO), and Space Station assembly and logistics resupply. The current performance of a 3 engine Shuttle - C exceeds 130,000 lbs (59,091 kg) to 220 nm (408 km) due to the removal of wings, tail section, crew cabin and man support systems. By trading this excess performance margin for design cost reductions, the Shuttle - C development presents some very unique design challenges not normally experienced in launch vehicle design. Additional performance provides significant advantages to the payload community by relieving critical weight targets and permitting use of less expensive materials, processes and simplier design solutions.