Parametric sizing study for future SSTO spaceplane

For the promotion of extended and diversified space activities, it is required to build the technology bases capable of supporting such space activities. Especially, the development of the low-cost space transportation system to and from lower earth orbit, as driven by the clear need for affordability and operational flexibility, would be key issue. For such advanced systems, the Spaceplane integrated by hypersonic airbreathing propulsion system, optimally configured as single stage to orbit, horizontal take-off and landing system, should be a potentially promising option. National Aerospace Laboratory of Japan (NAL) has initiated to study the spaceplane concept and develop the required hypersonic technology bases since 1987. The primary purpose of the spaceplane program is to provide technology as well as to provide a base research and development capabilities in critical disciplines for the future development of manned space transportation system. Airbreather/Rocket Combined Cycle (ARCC) engines could operate at many fuel/oxidizer mixture ratio conditions. The SSTO spaceplane vehicle size is depending on volume of hydrogen fuel. Hydrogen volume required for ARCC engine is related to mixture ratio in same propellants weight condition. Higher mixture ratio should be applied for the ARCC engine. Optimal rocket engine thrust level is obtained as a function of rocket engine phase start speed. Higher start speed reduce rocket engine thrust level. Rocket engine thrust level of 1.1 times of vehicle weight is required in case of rocket engine start at flight Mach number of 10 following the ARCC engine operation phase. *1 National Aerospace Laboratory of Japan, 7-44-1 Jindaiji-Higashi, Chofu, Tokyo, 182-8522, Japan Copyright©2001 by the American Institute of Aeronautics and Astronautics, Inc. All right reserved.