Future hypersonic vehicles will require high temperature seals to operate in high heat flux, oxidizing environments and restrict the flow of hot gases at temperatures up to 2000° F. They must be flexible enough to accommodate distorted sealing surfaces while remaining in contact with them to create an effective seal. They must resist damage as they are rubbed over rough, distorted sealing surfaces without incurring excessive increases in leakage due to wear. In some locations the seals may have to seal against rough thermal protection system (TPS) materials without sticking to their surfaces. Yet another high temperature seal need for the Air Forces Hypersonic Program is a high temperature elastomer seal or an alternative that can be formed into various seal geometries for use at temperatures of 700°F or greater, at which the conventional exotic high temperature elastomeric seals, such as Perfluoro Elastomer (FKKM, 630°F) and silicone (450°F) seals will fail. In this SBIR Project, Ultool proposes a proprietary rheological seal material solution to address both 2000°F and 700°F seal needs that is aggressively innovative, yet simple in design. It is expected the proposed high temperature rheological seal material will help advancing Air Forces hypersonic Technology Readiness Level (TRL). It is also anticipated that the high temperature seal material will have applications in private space industry, as well as many other private industrial applications, where an inexpensive high temperature seal is needed.