Investigation of next generation engine for reusable launch vehicle

Abstract

A new investigation on next generation engines for fully Reusable Launch Vehicle (RLV) is under way in Japan. The RLV requires not only high specific impulse of the propulsion but also significant improvements in thrust-to weight ratio at liftoff, life cycle capability and operability. This paper will describe the conceptual outline on a new engine research program for RLV based on the main component characteristics of the LE-7A engine. This engine will be driven with tap off cycle or gas generator cycle, not staged combustion, in order to increase sea level thrust-to-weight ratio. Extendible nozzle will be also installed to enhance the vacuum specific impulse. In addition, this paper will present a new concept of Liquefied Air Cycle Engine (LACE) to boost air breathing spaceplane. The LACE engine has significantly higher specific impulse and sea level thrust-to weight ratio than rocket engine.