Refractory Coated/Lined Low Density Structures

This project addresses the development of refractory coated or lined low density structures applicable for advanced future propulsion system technologies. The fundamental idea behind this concept was to design a hot-walled refractory material (ceramic and/or metallic) in the form of a thin coating or liner and have that supported by a low density structure such as graphite or various carbon-carbon composites, offering an attractive lightweight design option. This coated or lined low density structure combines the compatibility and hermetic seal of the ceramic and/or metallic hot-walled material with a lightweight, high strength to weight ratio support material such as graphite or carbon-carbon composites. The advantage of this particular concept can be observed by both the weight and cost savings compared to, for example, current solid monolithic refractory propulsion components. Lightweight structures are desirable for space transportation vehicle systems in order to reduce launch costs, increase mission flexibility, increase mission efficiency and add robustness with respect to the ability to add weight or additional materials to the mission with minimum sacrifice in performance. This general concept is applicable to thrust vector controls, combustion chambers, nozzles and thrusters. One study has shown that replacing a solid monolithic rhenium pintle and seat with a rhenium lined graphite version can offer both weight and cost savings as high as 80 - 90%.