S. D. Miller and Associates proposes to investigate a new class of thermal insulations that will enable thermal protection systems (TPS) on ceramic matrix composite (CMC) hot structures and Hypersonic Inflatable Aerodynamic Decelerators (HIAD). One insulation will embed silicon carbide aerogel in silicon carbide fibers to create a super-efficient, flexible insulation optimized for use at temperatures of 3500F and pressures >10 Torr. Another will demonstrate a lightweight, load bearing insulation that has borosilicate microballoons embedded in a borosilicate fiber matrix. The research team has prior experience developing a family of thermal insulations that have opacifiers embedded in a flexible fiber matrix. Testing has proven that these opacified fibrous insulations (OFI) are twice as efficient as unopacified insulations at temperatures >2000F and pressures <10 Torr. The proposed work will build on that proven concept by developing super-efficient, flexible insulations with aerogels, intumescents and microballoons embedded in silicon carbide, zirconia and silica fiber matrices. This will significantly reduce the weight of TPS on future NASA missions, reducing the cost of missions to Mars and other planets.