The RBCC, or rocket-based combined cycle propulsion system, was one of the two types of propulsion systems that may have been tested in the Boeing X-43 experimental aircraft. The RBCC, or strutjet as it is sometimes called, is a combination propulsion system that consists of a ramjet, scramjet, and ducted rocket, where all three systems use a shared flow path. A TBCC, or turbine-based combined cycle propulsion system, is a turbine engine combined with a ramjet and scramjet. A TRCC, or turbo rocket combined cycle propulsion system, is another combination propulsion system that combines an afterburning turbine engine with a RBCC propulsion system. See also SABRE (Synergistic Air Breathing Rocket Engine), a pre-cooled air-breathing rocket/RAM-jet engine based on General Dynamics' exploration of LACE concepts (Liquid Air Cycle Engine) by Reaction Engines, UK. References External links Performance Evaluation of the NASA GTX RBCC Flowpath - Glenn Research Center - NASA Parametric Study Conducted of Rocket-Based, Combined-Cycle Nozzles - Glenn Research Center - NASA Aerojet Successfully Tests RBCC Single Thruster, Demonstrating Tri-Fluid Rocket Injector Capabilities - SpaceRef Hypersonic inlet studies for a small-scale rocket-based combined-cycle engine, Journal of propulsion and power, 2007, vol. 23, no6, pp. 1160–1167, AIAA. Rocket-Based Combined-Cycle Engine (RBCC): Ramrocket, University of Toronto, High-Speed Vehicle Propulsion Systems Group. Jet engines