Leading-edge hypersonic research on airbreathing launch vehicles seeks to enable sustained hypersonic flight through Earth’s atmosphere, which will in turn enable routine, airline-type access to space. For reusable airbreathing access-to-space technologies, the Project is aligned with the goal defined in the 2007 National Plan for Aeronautics Research; namely, to demonstrate sustained, controlled, hypersonic flight. Successfully meeting this goal will require continued R&D into all areas of high-speed atmospheric flight, including integrated aircraft design, aerodynamics, aerothermodynamics, high-temperature structures and materials, lightweight and durable thermal-protection systems, supersonic combustion, and airbreathing propulsion concepts that operate from subsonic speeds into the hypersonic regime. The Hypersonic Project R&D goals include extending the use temperature and life of high-temperature materials and structures, reducing component mass, and developing airbreathing propulsion technology for Two-Stage-To-Orbit Turbine-Based Combined Cycle (TSTO/TBCC) vehicles.