A paper presents a study of multilayer thermal insulations for protecting spacecraft against aerodynamic heating during reentry into a planetary atmosphere. A multilayer insulation considered in the study comprised (1) thin ceramic/composite foils coated with gold for high reflectance interspersed with (2) fibrous polycrystalline alumina spacers, all wrapped in (3) a bag made of ceramic fabric. The radiation heat transfer in the fibrous insulation spacers was modeled using the two-flux method assuming isotropic scattering. Combined radiative and conductive heat transfer in such blankets were computed by use of a finite-volume numerical model. The model was validated in steady-state and transient thermal tests of sample insulations.

This work was done by Kamran Daryabeigi of Langley Research Center.

NASA Tech Briefs Magazine

This article first appeared in the November, 2002 issue of NASA Tech Briefs Magazine.

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