Overview of basic research activities on cryogenic composite propellant tanks in Japan

Extensive application of composite materials is one of the major technical challenges for drastic reduction of structural weight of the planned space planes and reusable launch vehicles (RLV). Propellant tanks are the dominating structural components of the vehicle structure and thus the application of carbon fiber reinforced plastics (CFRP) to these components is one of the most promising but challenging technologies for achieving the goal of weight reduction. The overview of current activities on basic research related to the application of CFRP to cryogenic propellant tanks in Japan is given. These research projects indicate that the load-carrying performance of the state-of-the-art material systems is at the sufficient level to be used in the CFRP tanks, leaving the problems related to permeability, durability and fabrication yet to be extensively investigated. The preliminary evaluations of thermal insulation materials and adhesive materials are also under way at NASDA. The research project led by NAL-Kakuda also exhibits the promising results of the CFRP components.