Si-N-B-C Aerogels for Thermal Protection System of Reentry Vehicles

The Air Force has an interest in new designs and new materials for TPS of hypersonic reentry vehicles. Military hypersonic vehicles will reenter the atmosphere according to trajectories that are more aggressive than that of the Space Shuttle Orbiter and expected to be able to maneuver in the atmosphere at speeds around March 20 for more than 4100 seconds. This will result in the extremely high temperatures and large heat fluxes (>12 Btu/ft2xs) at some areas on the vehicle's surface. Currently available TPS designs and materials are incapable of providing the level of protection required by the Air Force without significant increase in TPS weight and volume. Aspen Aerogels proposes to develop a new class of super insulation aerogel materials - Si-N-B-C aerogel composites for applications in TPS of the hypersonic reentry vehicles. Proposed insulation will have high temperature limit of 1400°C in air and will have thermal conductivity 20-30% lower than that of currently available materials. During the Phase II project the aerogel composites will be tested at the conditions similar to the conditions of reentry and TPS lay-ups development, fabrication and testing will be performed.