Fabric composite radiators for space nuclear power applications. Final report, March 1993

Abstract

Nuclear power systems will be required to provide much greater power levels for both civilian and defense space activities in the future than an currently needed. Limitations on the amount of usable power from radioisotope thermal generators and the limited availability of radioisotope heat source materials lead directly to the conclusion that nuclear power reactors will be needed to enhance the exploration of the solar system as well as to provide for an adequate defense. Lunar bases and travel to the Martian surface will be greatly enhanced by the use of high levels of nuclear power. Space based radar systems requiring many kilowatts of electrical power can provide intercontinental airline traffic control and defense early warning systems. Since the, figure of merit used in defining any space power system is the specific power, the decrease in die mass of any reactor system component will yield a tremendous benefit to the overall system performance. Also, since the heat rejection system of any power system can make up a large portion of the total system mass, any reduction in the mass of the heat rejection radiators will significantly affect the performance of the power system. Composite materials which combine the high strength, flexibility, and low mass characteristics of Si% based fibers with the attractive compatibility and heat transfer features of metallic foils, have been proposed for use m a number of space radiator applications. Thus, the weave of the fabric and the high strength capability of the individual fibers are combined with the high conductivity and chemical stability of a metallic liner to provide a light weight, flexible alternative to heavy, rigid, metallic radiator structural containers. The primary focus of this investigation revolves around two applications of the fabric composite materials, notably a fabric heat pipe radiator design and the Bubble Membrane Radiator concept.