The current status and future prospects of rocket propellants paralleling the development of rocket engines are described.
The use of a combination of liquid oxygen and liquid hydrogen (LO2/LH2) as a rocket propellant yields the highest performance and represents state of the art rocket technology as indicated by the main engine of the U. S. space shuttle.
Japan has succeeded in development of the LE-5 engine for use as the second stage of the H-I launcher and has been developing the LE-7 engine with a thrust of 100 tonf for use as the first stage of the H-II launcher. Also, Europe has been developing the HM-60 engine, which will produce much the same thrust as the LE-7, for use with the ARIANE-5 launcher.
Currently, the development of LO2/LH2 engines has been a key to attain the potential of activities in space. While, in near future, a dual fuel engine combining LO2/LH2 and LO2/ hydrocarbon engine will be realized for use with single-stage-to-orbit vehicles, and LNG (methane) and LPG (propane) will be used as fuels for rocket and ramjet engines.
