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This is Part 3 of a development program to evaluate candidate nonablative aeroshell designs. The primary goal of this C/C aeroshell development task was to demonstrate the feasibility and performance of a lightweight C/C non-ablative aeroshell design that integrates advanced C/C materials and structural configurations. The thermal performance was evaluated by Arc Jet testing at NASA Ames of representative structural models. In this phase of the program, new carbon-carbon materials and structural core designs were evaluated, as well as an alternative aerogel material. The test models were composed of a quasi-isotropic Carbon/Carbon(C/C) front face sheet (F/S), eggcrate or honeycomb core, C/C back F/S, Carbon and resorcinol-formaldehyde aerogel insulation. Part One of this work [1] demonstrated the feasibility through arc-jet testing and Part Two [2] included analytical modeling of the test geometry to validate the design.

Candidate Aeroshell Test models composed of a quasi-isotropic Carbon/Carbon(C/C) front face sheet (F/S), eggcrate core, C/C back F/S, Carbon Aerogel insulation, C/C radiation shield and the C/C close-out were constructed based on the analytical temperature predictions presented in Part One of this work[1]. The analytical results obtained for a simulated Mars entry of a 2.9 meter diameter cone shaped Carbon-Carbon Aeroshell demonstrated the feasibility of the design. These results showed that the maximum temperature the front F/S reached during the decent was 1752 °C with the resulting rear temperature reaching 326 °C in the thermal model. Part Two of this work documents the thermal modeling and correlation for the Mars Aeroshell test sample and fixture. A finite difference, SINDA/G, thermal math model of the test fixture and sample was generated and correlated to data from an arc jet test conducted at the NASA Ames Research Center's interactive heating facility.

A transient thermal analysis of a Carbon/Carbon (C/C) Mars Entry Non-Ablative Aeroshell Assembly was performed to determine the maximum temperatures it would reach during a Mars entry. The purpose of this thermal analyses was to (1) determine the maximum temperatures of the 5 layers and the close-out which make up the aerothermal shield and (2) to transmit these temperatures from SINDA/G finite difference format to finite element format in COSMOS/M structures/dynamic models using Technical Alliance Group (TAG) developed SINDA/ G temperature translator software (STT).