%0 Journal Article %A Kanda, Takeshi %D 2009 %I Begell House %N 5 %P 455-459 %R 10.1615/IntJEnergeticMaterialsChemProp.v8.i5.60 %T RESEARCH ACTIVITIES ON ROCKET-RAMJET COMBINED-CYCLE ENGINE IN JAXA %U https://www.dl.begellhouse.com/journals/17bbb47e377ce023,2a4341eb3d756b81,727fe4ab723fc2b8.html %V 8 %X For the next generation of transportation systems, high reliability is required for credible and safe transportation. To carry out such a demand, a weight margin for a supplemental redundant system is necessary. At the same time, a more economical space transportation system is required. Since a required velocity increment is specified by a target orbit, the specific impulse of the booster stage has been increased and the use of an air-breathing engine has been studied. Since kinetic energy is proportional to a square of the velocity, the use of an air-breathing engine, e.g., the scramjet engine, in a hypersonic regime, is effective to attain such a large energy. Although the scramjet engine has superior performance, another engine is required to accelerate the vehicle from take-off to supersonic speed. When the vehicle with the scramjet increases to a higher altitude, a rocket engine is further required. The rocket-ramjet combined cycle engine, i.e., the rocket-based combined cycle engine (RBCC), is a combination of the rocket engine and the ramjet engine. The engine enhances an average specific impulse, compared to conventional rocket engines, and can operate from take-off to hypersonic speed. Japan Aerospace Exploration Agency (JAXA) has been studying the scramjet and the combined cycle engine. Herein, the recent activities of JAXA regarding them are presented. %8 2009-12-01