Selection of Materials and Design of Multilayer Lightweight Passive Thermal Protection System

Abstract

A methodology has been established aiming to design a lightweight thermal protection system (TPS), using advanced lightweight ablative materials developed at the NASA Ames Research Center. An explicit finitedifference scheme is presented for the analysis of onedimensional transient heat transfer in a multilayer TPS. This problem is solved in two steps, in the first step, best candidate materials are selected for TPS. The selection of materials is based mainly on their thermal properties. In the second step, the geometrical dimensions are determined by using an explicit finitedifference scheme for different combinations of the selected materials, and these dimensions are optimized for the design of lightweight TPS. The best combination of material employs silicone impregnated reusable ceramic ablator (SIRCA), Saffil, and glasswool for the first, second, and third layer, respectively.