Preliminary Development of a Multifunctional Hot Structure Heat Shield

Abstract

Development of a Multifunctional Hot StructureHeat Shield concept has initiated with the goal to provide advanced technology with significant benefits compared to the current state of the art heat shield technology. The concept is unique in integrating the function of the thermal protection system with the primary load carrying structural component. An advanced carbon-carbon material system has been evaluated for the load carrying structure, which will be utilized on the outer surface of the heat shield, and thus will operate as a hot structure exposed to the severe aerodynamic heating associated with planetary entry. Flexible, highly efficient blanket insulation has been sized for use underneath the hot structure to maintain desired internal temperatures. The approach was to develop a preliminary design to demonstrate feasibility of the concept. The preliminary results indicate that the concept has the potential to save both mass and volume with significantly less recession compared to traditional heat shield designs, and thus provide potential to enable new planetary missions.

A Multifunctional Hot Structure Heat Shield Concept for Planetary Entry

“…7), results showed high local stresses in the ACC-6 material in the vicinity of the attachment points in the finite element model (FEM). These high stresses were occurring in the outer fibers of the T-beam stiffeners being modeled as beam elements, which were experiencing significant bending.…”

“…Consequently, the preliminary development initiated with a focus on only the capsule heatshield, i.e., the heatshield without rigid deployable extensions, for an ISS return application. 7 This work included a trade study comparing the HOST concept to a traditional heatshield design. The initial results indicated that the HOST concept has the potential to save both mass and volume with significantly less recession compared to traditional heatshield designs.…”

Development verification of coatings made from porous ceramic-matrix composite materials

“…PICA, which stands for Phenolic Impregnated Carbon Ablator, is composed of a porous carbon base and phenol-formaldehyde resin. However, studies conducted at NASA Langley research center [1] show that the use of carbon materials such as ACC-6, together with high porosity thermal insulation, makes it possible to create more weight-efficient designs. Ceramic matrix composites (CMC) reinforced with carbon fiber, despite their high oxidation-resistance and erosion-resistance and good mechanical characteristics, possess high density and thermal conductivity, which reduces their attraction as heat-shield materials.…”