ABLATIVE COMPOSITES FOR LIFTING REENTRY THERMAL PROTECTION.

Abstract : An exploratory materials formulation, development and characterization program was conducted on low density ablative composites (16 to 25 pounds per cubic foot) to provide improved thermal protection materials for future lifting entry vehicles. Two types of ablative composites were identified, one material was based on a biphenol formaldehyde resin and the other was based on a rigid silicone resin. Both materials were formulated with coated phenolic microballoons and alumina-chromia-silica fibers. Characterization tests have been conducted to obtain ablative mechanical and thermal properties of the newly developed materials. (Author)