Some nose cap studies for a manned re-entry glider

Abstract

On the nose cap of manned re-entry gliders equilibrium temperatures between 3000° and 4000°F arise for a relatively long time; the total heat input reaches 300,000 B.t.u./ft2. A nose cap design is analyzed that disposes of most of this heat by a re-radiation into space; this way, an efficiency of 30,000 B.t.u./lb functional weight (insulation plus cooling fluid evaporated) can be achieved. The proposed insulation material is a highly porous ceramic. Its conformance with the design requirements is discussed, and test results are communicated. Furthermore, the beneficial effects of high porosity on thermogradient capability and insulation efficiency of ceramic materials are discussed on the basis of simple analytical considerations.