TBCC Propulsion for a Mach 6 Hypersonic Airplane

Hypersonic speed can be achieved through rocket-boost, air-breathing propulsion, or a high-energy state from orbit. This paper will focus on air-breathing hydrocarbon fueled hypersonic flight at Mach 6. Flight demonstration of a Mach 6 hypersonic airplane in a realistic environment will enable the future development of re-usable high-speed operational systems for strike, ISR, or other national need missions. Technologies enabling this capability are turbine-based combined cycle (TBCC) propulsion, efficient aerodynamics, high temperature structures, and thermal management techniques. The TBCC propulsion system enables complete transition from low-speed to high-speed flight and enables re-usable aircraft-like operations take-off from a conventional runway under turbojet power, acceleration to Mach 6 under combined propulsion, deceleration, and turbojet powered landing – without the need for carrier aircraft or rocket assist. The Defense Advanced Projects Agency (DARPA) Falcon Combined-Cycle Engine Technology (FaCET) and Mode Transition (MoTr) programs will ground test TBCC propulsion, a critical step to enabling flight demonstration of a Mach 6 hypersonic airplane. Mach 6 Airplane Enablers After 50 years of many stops and starts in air-breathing hypersonic research programs, there have been only two successful flight demonstrations, ASALM and X-43, as shown in Figure 1. In each case, carrier aircraft and/or rockets were required. Aerospace Plane National Aerospace Plane (NASP) National Aerospace Initiative (NAI) ASALM Ramjet HRE X-24C NHRF HST SED ARRMD X-43A Hyper-X Scramjet