The Road from the NASA Access-to-Space Study to a Reusable Launch Vehicle

portunity to reduce launch costs, and improve safety and reliability was to develop a fully reusable single-stage-to-orbit vehicle capable of delivering 25,000 lb to the International Space Station. The study identified many technologies that had to be matured before a commitment could be made to build such a vehicle. NASA accepted the recommendation and the need for new technology as the key to low-cost, reliable space transportation. A decision was also made by NASA that it should purchase future launch services and no longer operate a Space Transportation System. To meet the objectives of a low-cost, reliable, commercially owned space transportation system, NASA believes that the required technologies must be matured sufficiently before a commercial organization will commit the financial resources required for development. To aid in this matura-tion process, NASA entered into a cooperative agreement with Lockheed Martin Corporation to develop the X-33. The X-33 is a half-scale demonstrator of a single-stage-to-orbit, all rocket-powered vehicle. The X-33 will demonstrate the implementation and testing of many of the required technologies. In addition to the X-33, NASA has funded ground-test programs for the critical technologies , and conceptual through preliminary design studies for the operational reusable launch vehicle. The combination of the X-33, the ground-based program and reusable launch vehicle studies are expected to provide the necessary information to determine the viability of a commercially developed launch vehicle. This information will be available soon after the turn of the century. This paper will discuss the results of the access-to-space study, expected results and status of the X-33, the ground test programs, and the reusable launch vehicle study. Nomenclature CFD Computational Fluid Dynamics cg center of gravity FY Fiscal Year H2 Hydrogen LH2 Liquid Hydrogen LOX Liquid Oxygen Abstract NASA has established a goal of providing low-cost reliable access to space. While this goal has been around for many years, it received a major impetus when the U.S Congress mandated the Access-to-Space study in 1993. This study concluded that a rocket powered single stage to orbit vehicle offered the best opportunity for low-cost reliable space transportation by the first decade of the new millennium. This required a focused technology development program before such a vehicle could be built. NASA recognized that no commercial entity would commit to the development of a single-stage-to-orbit vehicle without the U.S. Government's participation. To this end, NASA entered into a cooperative agreement with industry to mature the …