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.