Technology Roadmap for Dual-Mode Scramjet Propulsion to Support Space-Access Vision Vehicle Development

AIAA 2002-5188Technology Roadmap for Dual-Mode Scram jet Propulsion to Support Space-Access Vision VehicleDevelopmentCharles E. Cockrell, Jr.*, Aaron H. Auslender t, R. Wayne Guy S,Charles R. McClinton §, Sharon S. Welch §§NASA Langley Research Center, Hampton, VAAbstractThird-generation reusable launch vehicle(IRLV) systems are envisioned that utilizeairbreathing and combined-cycle propulsion to takeadvantage of potential performance benefits overconventional rocket propulsion and address goals ofreducing the cost and enhancing the safety ofsystems to reach earth orbit. The dual-modescramjet (DMSJ) forms the core of combined-cycleor combination-cycle propulsion systems for single-stage-to-orbit (SSTO) vehicles and provides most ofthe orbital ascent energy. These concepts are alsorelevant to two-stage-to-orbit (TSTO) systems withan airbreathing first or second stage. Foundationtechnology investments in scramjet propulsion aredriven by the goal to develop efficient Mach 3-15concepts with sufficient performance and operabilityto meet operational system goals. A brief historicalreview of NASA scramjet development is presentedalong with a summary of current technology effortsand a proposed roadmap. The technologyaddresses hydrogen-fueled combustor development,hypervelocity scramjets, multi-speed flowpathperformance and operability, propulsion-airframeintegration, and analysis and diagnostic tools.IntroductionThe United States National Aeronautics andSpace Administration (NASA) has established astrategic goal of creating a safe, affordable highwaythrough the air and into space. Candidate third-generation reusable launch vehicle (RLV)architectures include single-stage and two-stageconcepts which utilize airbreathing, combined-cycleand combination-cycle propulsion systems to takeadvantage of potential performance gains overconventional rocket-propelled concepts. An access-to-space roadmap has been established thatfocuses on airframe-integrated hypersonicairbreathing propulsion development throughfoundation technology investments, grounddemonstration and flight validation. Successfulimplementation of this roadmap requires a robusttechnology development program to mature aspectsof the propulsion system and integrated aero-propulsive vehicle performance through bothanalytic and experimental research.Figure 1 shows a comparison of nominalspecific-impulse values for airbreathing enginecycles vs. rockets. The dual-mode scramjet (DMSJ)forms the core of combined-cycle or combination-cycle airbreathing propulsion systems and providesmost of the orbital ascent energy for single-stage-to-orbit (SSTO) airbreathing launch vehicle systems.The term "dual-mode scramjet" refers to an enginecycle that can operate in both subsonic combustionand supersonic combustion modes. Rocket-basedcombined cycle (IRBCC) concepts are being studiedwhich integrate rocket thrusters with the DMSJflowpath for low-speed propulsion. Turbine-basedcombination cycle (TBCC) concepts are also beingexamined which integrate a gas turbine engine andDMSJ in a dual-flowpath configuration.Hypersonic airbreathing propulsion researchconducted by NASA spans over 40 years. 1-4Historical work includes the hypersonic researchengine (HIRE), airframe-integrated scramjet groundtesting and component development, the X-30National Aerospace Plane (NASP) program, and,more recently, the Hyper-X (X-43) flight* AirbreathingPropulsionProgramManager,AdvancedSpaceTransportationProgramOffice,SeniorMember,AIAA.t AssistantHead,HypersonicAirbreathingPropulsionBranch.:1:Head,HypersonicAirbreathingPropulsionBranch.§ TechnologyManager,Hyper-XProgramOffice.§§ Head,AdvancedSpaceTransportationProgramOffice.Copyright © 2002 by American Institute of Aeronautics andAstronautics, Inc. No copyright is asserted in the United StatesunderTitle 17, U.S. Code.The U.S. Governmenthas a royalty-free license to exercise all rights under the copyright claimedherein for governmental purposes.All other rightsare reservedbythe copyrightowner.Isp