Description: NASA future missions place stringent requirements on high temperature and light-weight materials.This proposal addresses some of the most challenging materials issues with respect to Hot Structures, very high temperature, up to 4500 degrees F, applications.The very successful NASA led X-43A hypersonic flight proved the ability to use state of the art (SOTA) 2D C-C with oxidation coating system. However, current material systems can only offer limited temperature capability (<3000 °F) and mostly for single use application. In Phase I, two innovative technologies, undercoat and FGM multi-layer coats, were developed and screened. They were further integrated into two SOTA C-C composites. Oxidation protected C-C samples were torch tested at 3500 F/ 30 minutes, at 4200 F/ 2 minutes up to 10 cycles, and at 3000 F/cool/ 4000 F cycles showing very promising results. The combined effects of the undercoat and FGM spray coats provide repeatable performance by creating a glass forming, conforming and adherent external coating to protect the C-C from being oxidized.The overall objective of the proposed P-II is to further develop and optimize a robust, tailorable, and affordable oxidation protection system for C-C TPS and C-C hot structure by integrating our undercoat and FGM multi-layer spray coat technologies into at least two grades C-C composites (T300 and P30 2D C-C) meeting higher temperature performance up to 4500 F and multi-use applications. Work plan includes 12 tasks over 24 month grouped into 5 categories.Once further optimized and validated under Phase II, these technologies can easily be integrated into SOTA C-C using current manufacturing facilities. The resulting oxidation protected C-C could be tailorable, affordable, and easily scaled up for large components or structure required in future NASA, DoD and commercial space applications.

Benefits: This proposal addresses some of the most challenging materials issues with respect to Hot Structures, very high temperature, up to 4500 degrees F, applications. The very successful, record breaking, NASA led X-43A hypersonic flight proved the ability to use state of the art (SOTA) material/coating system. However, current material systems can only offer limited temperature capability (<3000 �F) and mostly for single use application. The development and validation of a family of robust oxidation resistant C-C composites that are high temperature capable and multi-use will enable NASA designers to implement hot structure solutions in lieu of heavy parasitic passive insulation system in future NASA Space Exploration vehicles and other missions, The primary focus of Phase II effort is to provide new TPS solutions for NASA Space Exploration vehicles, including but not limited to hot structure, control surface/ leading edge, and upper stage extension nozzle, where a new generation of oxidation resistant C-C capable for higher temperature up to 4500 F and also for multi-use, well beyond the Space Shuttle C-C technology using SiC (via pack cementation) & glass sealant, is required. In addition, this technology would also have applicability in future hypersonic applications. Specifically NASA future goals to use scramjet engine technology where the unique Phase II technology would be highly applicable to leading edges, fins, etc.

This proposal addresses some of the most challenging materials issues with respect to Hot Structures, very high temperature, up to 4000 degrees F, applications. The very successful, record breaking, NASA led X-43A hypersonic flight proved the ability to use state of the art (SOTA) material/coating system for short duration, single mission, and very high temperature applications. However, current material systems can only offer limited temperature capability (<3000 �F) and mostly for single use application at higher temperature. The development and validation of a family of robust oxidation resistant C-C composites that are high temperature capable, multi-use, reliable, scale-up able, and affordable will enable non-NASA designers to implement hot structure solutions in lieu of parasitic passive insulation system resulting in significant weight reduction in future non-NASA applications. Several DoD organizations are currently actively pursuing hypersonic vehicles for both advanced missile systems, as well as sophisticated surveillance vehicles, where high performance oxidation resistant C-C are required for Aeroshell, leading edge, and flow path duct of the scramjet. High performance upper stage C-C extension nozzles, capable of operating up to 4000 F and multi-use, are also sought by both DoD and many commercial space companies.