• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.4
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• pp.370-377
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• 1995

The recombination of oxygen and nitrogen atoms on the surfaces of two coating m materials of the Space Shuttle Orbiter (SSO), a reaction cured glass (RCG) and a spinel (C742), was investigated. The recombination probability, $\gamma$, i.e., the probability that atoms im p pinging on the surface will recombine, was measured in a diffusion reactor. Value of $\gamma$ for oxy g gen atom on C742 ($3 {\times} 10^{-2}$) was much higher than that on RCG ($4 {\times} 10^{-4}$) at the tempera t ture of SSO re-entry (ca. 1000K). The higher value of $\gamma$ on C742 indicates a higher number d density of active sites than RCG. It suggests the possibility of designing less active surfaces by i inducing the desorption at lower temperature.

• Journal of Powder Materials
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• v.29 no.6
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• pp.477-484
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• 2022

Thermal protection systems (TPS) are a group of materials that are indispensable for protecting spacecraft from the aerodynamic heating occurring during entry into an atmosphere. Among candidate materials for TPS, ceramic insulation materials are usually considered for reusable TPS. In this study, ceramic insulation materials, such as alumina enhanced thermal barrier (AETB), are fabricated via typical ceramic processing from ceramic fiber and additives. Mixtures of silica and alumina fibers are used as raw materials, with the addition of B4C to bind fibers together. Reaction-cured glass is also added on top of AETB to induce water-proof functionality or high emissivity. Some issues, such as the elimination of clumps in the AETB, and processing difficulties in the production of reusable surface insulation are reported as well.