The structure of space transportation system mostly consists of propellant (fuel and oxidizer) tanks. Metallic materials such as aluminum alloys are used as the tank materials of the current expendable rockets. In order to realize reusable space transportation system, CFRP (Carbon Fiber Reinforced Plastic), which has superior specific strength than metallic materials, is to be applied to the cryogenic propellant tanks in order to improve the structural efficiency. In this laboratory, composite high-pressure hydrogen gas and liquid hydrogen tanks with superior gas barrier characteristics, and flame-retardant composite liquid oxygen tanks are studied.
