Processing of Rigidized Rei-mullite Insulative Composites

Systematic development and evaluation of ceramic fiber Mullite are summarized: (1) Major reductions in thermal protection system weight have been achieved by reducing the density and thermal conductivity of the insulation by 20 and 25 percent; (2) already adequate structural margins-of-safety have been greatly enhanced by increasing the tensile strength and strain-to-failure capabilities of the insulation by factors of 3 and 2; (3) cost effectiveness has been increased through the achievement of a high degree of uniformity and reproducibility of properties and through process simplification and binder modifications; and (4) maximization of multimission capability at surface temperatures of 1644 K has been achieved through firing cycle adjustments and the development of a material with high dimensional stability.