C
National Aerospace Initiative Hypersonics Programs and Technologies

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

X-43A Hyper-X

The first demonstrator vehicle in NASA’s “Hyper-X” series of experimental hypersonic ground and flight test vehicles, the X-43A will demonstrate “air-breathing” engine technologies for future hypersonic aircraft and/or reusable space launch vehicles, achieving speeds above Mach 5, or five times the speed of sound [Figure C-1]. The X-43A is intended to dramatically increase payload capacity or reduce vehicle size. A successful flight could mark the first time a nonrocket, air-breathing supersonic-combustion ramjet—or “scramjet”—engine has powered a vehicle in flight at hypersonic speeds. The next flight test of the X-43A is scheduled for January 2004. (NASA, 2003a)

X43-B

The X-43B will be the first reusable vehicle in the X-43 series of X-planes. Not requiring a booster, it will be air-launched from NASA’s new B-52H aircraft, in a manner similar to the X-15, and then flown to Mach 7 under its own power. It is an ambitious undertaking and will go a long way toward advancing technology readiness levels for future hypersonic aircraft and air-breathing space access vehicles.

Two different engine systems are being considered for the X-43B. The first is a rocket based combined cycle (RBCC) engine, which is a scramjet with rockets imbedded in the internal flowpath. With this engine approach, the rockets are operated initially, up to a flight speed of Mach 3 or 4. The rockets are then turned off, and the engine is operated in ram/scramjet mode to Mach 7-8 for hydrocarbon fuel, or Mach 12-15 for hydrogen fuel. The second is a turbine based combination cycle (TBCC) system, which uses separate low and high-speed engines. Hydrocarbon-fueled turbojet or turbo-ramjet engines are used for flight up to Mach 4, and then separate ram/scramjet engines are used for flight up to Mach 7-8 (hydrocarbon fuel) or Mach 12-15 (hydrogen fuel). (Orton, 2002)



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Evaluation of the National Aerospace Initiative C National Aerospace Initiative Hypersonics Programs and Technologies NATIONAL AERONAUTICS AND SPACE ADMINISTRATION X-43A Hyper-X The first demonstrator vehicle in NASA’s “Hyper-X” series of experimental hypersonic ground and flight test vehicles, the X-43A will demonstrate “air-breathing” engine technologies for future hypersonic aircraft and/or reusable space launch vehicles, achieving speeds above Mach 5, or five times the speed of sound [Figure C-1]. The X-43A is intended to dramatically increase payload capacity or reduce vehicle size. A successful flight could mark the first time a nonrocket, air-breathing supersonic-combustion ramjet—or “scramjet”—engine has powered a vehicle in flight at hypersonic speeds. The next flight test of the X-43A is scheduled for January 2004. (NASA, 2003a) X43-B The X-43B will be the first reusable vehicle in the X-43 series of X-planes. Not requiring a booster, it will be air-launched from NASA’s new B-52H aircraft, in a manner similar to the X-15, and then flown to Mach 7 under its own power. It is an ambitious undertaking and will go a long way toward advancing technology readiness levels for future hypersonic aircraft and air-breathing space access vehicles. Two different engine systems are being considered for the X-43B. The first is a rocket based combined cycle (RBCC) engine, which is a scramjet with rockets imbedded in the internal flowpath. With this engine approach, the rockets are operated initially, up to a flight speed of Mach 3 or 4. The rockets are then turned off, and the engine is operated in ram/scramjet mode to Mach 7-8 for hydrocarbon fuel, or Mach 12-15 for hydrogen fuel. The second is a turbine based combination cycle (TBCC) system, which uses separate low and high-speed engines. Hydrocarbon-fueled turbojet or turbo-ramjet engines are used for flight up to Mach 4, and then separate ram/scramjet engines are used for flight up to Mach 7-8 (hydrocarbon fuel) or Mach 12-15 (hydrogen fuel). (Orton, 2002)

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Evaluation of the National Aerospace Initiative FIGURE C-1 X-43A hypersonic experimental vehicle—artist concept in flight. SOURCE: NASA, 1999. X-43C Hypersonic Demonstration Vehicle Now in development, the X-43C is expected to accelerate to a maximum potential speed of about 5,000 mph, and could undergo flight-testing as early as 2008. NASA will develop, test and fly the Hyper-X series over the next two decades to support development of future-generation reusable launch vehicles and improved access to space. (NASA, 2002a) The X-43C demonstrator, powered by a scramjet engine developed by the U.S. Air Force, is now in development. The X-43C is expected to accelerate from Mach 5 to Mach 7, reaching a maximum potential speed of about 5,000 mph. NASA will begin flight-testing the X-43C in 2008. (NASA, 2002b) NASA’s Advanced Space Transportation Program (ASTP) Hypersonic Investment Area NASA Marshall’s Advanced Space Transportation Program (ASTP) is investing in hypersonics as part of a new national hypersonics strategy formulated by NASA, the Air Force, Army, Navy and Defense Advanced Research Projects Agency. (NASA, 2003b) Rocket-Based Combined Cycle Engines Rocket-Based, Combined-Cycle (RBCC) engines are currently being explored as advanced propulsion for a variety of space launch, cruise aircraft and unmanned systems. This flexible propulsion

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Evaluation of the National Aerospace Initiative system can be customized to meet the unique needs of both commercial and military applications. RBCCs can utilize either storable or cryogenic propellants dependent on system requirements. RBCC powered systems can provide significant advantages in range, mission time, weight, payload, load-out, mission profile flexibility, and cost over competing conventional propulsion solutions. The Boeing RBCC can be scaled, so that development and demonstration of the basic core flowpath will support a broad spectrum of postulated applications. The Boeing RBCC will operate in air-augmented rocket, ramjet, scramjet and rocket propulsive modes to deliver high average Isp at required thrust levels for the earth to orbit mission. Fuel injection locations are varied during the flight to accommodate the unique needs of each operating mode. (Boeing, 2003) Turbine-Based Combined Cycle Engines NASA’s Advanced Space Transportation Program has tasked Glenn Research Center (GRC) to lead the high Mach turbine propulsion and Turbine-Based Combined Cycle (TBCC) efforts. In response to this request, GRC has developed the RTA Project to develop and demonstrate high Mach turbine propulsion and Turbine-Based Combined Cycle (TBCC) propulsion for Space Access. (NASA, 2003c) The Turbine-Based Combined Cycle (TBCC) engine project seeks to deliver a Mach 4+ hypersonic propulsion system in this decade. (NASA, 2003d) U.S. AIR FORCE HyTech Program This Air Force, NASA, and Pratt & Whitney hypersonic missile program is being developed using hydrocarbon fuel. Most programs have used only hydrogen as a fuel for scramjets because of the brief time for combustion (~1 ms). The Hypersonic Technology (HyTech) Program instead uses conventional jet fuel (JP-7). The heat generated in the walls of the combustion chamber is used to crack the fuel into lighter and more volatile elements. These elements then generate positive thrust at Mach 6 and higher when they enter the supersonic flow and burn. Future program goals will be to have engines useful for both missiles and reusable vehicles (Hobbyspace, 2003; Jackson, 2003). Pratt & Whitney (P&W) Space Propulsion, teamed with U.S. Air Force researchers under the Hypersonic Technology (HyTech) Program, has completed testing of a revolutionary scramjet engine. The ground demonstration engine number one (GDE-1), which weighs less than 150 pounds, was tested at speeds of Mach 4.5 and Mach 6.5 in hypersonic ground test facilities. GDE-1 was the world’s first flight-weight, hydrocarbon-fueled scramjet engine, and used standard JP-7 fuel to both cool engine hardware and fuel the engine’s combustor. (Pratt & Whitney, 2003) The objective of the HyTech program is to demonstrate the operability, performance, and structural durability of a liquid hydrocarbon (jet fuel) supersonic combustion ramjet (Scramjet). The near term application of this technology is a long range hypersonic cruise missile that is logistically supportable in a combat environment and can defeat time-sensitive targets and hard and deeply buried targets. In the far term, the scramjet technology enables a Mach 8-10 strike/reconnaissance aircraft and affordable, on-demand access to space with aircraft like operations. (AFRL, 2003) Integrated High-Performance Turbine Engine Technology Program The Integrated High Performance Turbine Engine Technology (IHPTET) program, started in 1988, has an aggressive technology development plan to leapfrog technical barriers and deliver twice the propulsion capability of today’s systems by around the turn of the century. Unprecedented teaming

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Evaluation of the National Aerospace Initiative of the Army, Navy, Air Force, NASA, DARPA and industry, in each of the technology areas, is underway. The main focus of these ‘Technology Teams in Action’ is to advance military aircraft superiority through high performance, affordable, robust turbine engines. (AFRL, 2003) The Integrated High Performance Turbine Engine Technology (IHPTET) program started in 1988, with a goal of doubling the propulsion capability by the year 2005. To meet this goal the Army, Navy, Air Force, NASA, DARPA, and industry united to develop high performance, affordable, robust turbine engines. The development of new materials and advanced structural designs is crucial to IHPTET’s success and future robust engine systems with stronger and more durable components. With this emphasis on new materials development, many breakthroughs in high temperature materials and processes owe their success to the IHPTET program. Furthermore, many of these materials form the foundation for more efficient rocket engines being examined under a similar program (Integrated High Payoff Rocket Propulsion Technology—IHPRPT). (IHPTET, 2003) Single-Engine Demonstrator The Single-Engine Demonstrator (SED) program will demonstrate scramjet engine and vehicle technologies in a relevant flight environment, making them ready for transition to weapon system development. The primary program objective is to validate performance of the fixed-geometry hypersonic technology (HyTech) scramjet engine and the integration of that engine into an airframe based on the ARRMD vehicle design. The planned mission profile is to have the demonstrator carried by a B-52 aircraft to an altitude of about 35,000 feet and released (Pratt & Whitney, 2004). Initially propelled by a solid rocket booster, the recoverable scramjet demonstrator takeover will occur at approximately Mach 4.5, where it then will accelerate to flight speed between Mach 6.0 and 7.0+. This flight profile will expose the demonstrator to both high dynamic pressure during the acceleration phase and low dynamic pressure in the cruise phase. Five to eight flight tests are planned, but additional flights are possible for testing related technologies such as thermal protection systems, guidance, high speed dispense, and so on (McDaniel, 2004). Atmospheric Interceptor Technology Program The United States Air Force atmospheric interceptor technology (AIT) program is developing, integrating and demonstrating lightweight launch vehicle technologies within the atmosphere to support ballistic missile technology. The Air Force has a requirement to develop target vehicles that have the ability to simulate a realistic incoming ballistic missile trajectory. This capability will be used to evaluate the performance and utility of currently existing radar on the West Coast of the United States and provide an experimental platform for evaluation of future technology. (U.S. Air Force, 1999) AIT aims to improve the capability of ballistic missile defense systems that operate within the earth’s atmosphere, such as theater high altitude area defense and the Navy area defense system. AIT also seeks to double average velocities, resulting in increases of defended areas by about a factor of three. These performance improvements are relevant to cruise missile defense as well as ballistic missile defense. The AIT program is composed of four critical technology areas: a strapdown seeker design, a cooled window, a solid divert-and-attitude control system and a composite material airframe. (Granone & Davis, 2000)

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Evaluation of the National Aerospace Initiative U.S. NAVY RATTLRS Program Revolutionary Approach to Time-critical Long Range Strike (RATTLRS) Flight Demonstration Project. Sources/respondents should have a demonstrated capability to successfully design, fabricate, integrate and flight test a tactical strike-weapon-class supersonic air vehicle. This notice requests information on project execution plans and identification of the requisite technologies to ascertaining the feasibility and risks associated with such a flight demonstration project. The total projected technology development and flight demonstration cost is approximately $50M. As an applied research Science and Technology demonstration, RATTLRS will culminate in flight demonstrations of an integrated air vehicle, powered only by a supersonic turbine engine, in a size/ shape/weight configuration that is traceable to a tactical weapon system. The flight demonstration vehicle is expected to accelerate from a subsonic air launch condition to a minimum of Mach 3 using only turbine propulsion. For RFI response purposes, assume first demonstration flight prior to 36 months after project initiation, and all flight demonstrations completed by 45 months after project initiation. The flight vehicle to be demonstrated within RATTLRS should be a demonstration air vehicle only, having traceability to one of the following potential weapon systems: An air-launched (compatible with the F/A-18 launch platform) medium range weapon with a maximum vehicle weight of 1800 lbs including 500 lbs payload, or a ship-launched (Vertical Launch System (VLS) compatible) long-range weapon with a maximum weight of 3400 lbs including 750 lbs payload (includes vehicle and any booster required for VLS launch), or one vehicle compatible to both launch options. (U.S. Navy, 2003) U.S. ARMY Scramfire Scramfire is a 120-mm powered munition “that accelerates throughout flight to the target and offers increased velocity at the target for direct fire weapons or increased range for indirect fire” (CAS, 2003). The scramjet-powered munition (see Figure C-2) demonstrated structural integrity by inflight x-ray and had a self-sustaining thrust that enabled a flight velocity of 8,100 ft/sec over 240 ft flight (Sega, 2003). Hypersonic Interceptor Missile Scramjet Program Provide optimized design for a Mach 10-12 H2 fueled scramjet powered interceptor missile to be used for defense against cruise missiles and for Army long range attack operations (long range FIGURE C-2 Scramjet powered munitions. SOURCE: Sega, 2003.  

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Evaluation of the National Aerospace Initiative strike). Work is to be performed in collaboration with test program providing full scale shock tunnel test data at fully duplicated flight conditions, and, with a team of University experts performing subscale experiments. (Kennedy and Nash, 2003) DEFENSE ADVANCED RESEARCH PROJECTS AGENCY DARPA/Navy HyFly Program The Hypersonics Flight Demonstration (HyFly) program will develop and demonstrate advanced technologies for hypersonic flight. Flight-testing will be initiated early in the program and progress from relatively simple and low-risk tests through the demonstration of an increasingly more difficult set of objectives. The ultimate goals of the program are to demonstrate a vehicle range of 600 nautical miles with a block speed of 4,400 ft per sec, maximum sustainable cruise speed in excess of Mach 6, and the ability to deploy a simulated or surrogate submunition. Technical challenges include the scramjet propulsion system, lightweight, high-temperature materials for both aerodynamic and propulsion structures, and guidance and control in the hypersonic flight regime. Recently demonstrated performance in ground testing of the dual combustion ram-jet engine coupled with advances in high temperature, lightweight aerospace materials are enabling technologies for this program. The program will pursue a dual approach. The core program will focus on development and demonstration of capabilities requisite for an operational weapon. A separate effort will be performed in parallel to demonstrate advanced propulsion technologies and develop low-cost test techniques. DARPA and the Navy established a joint program to pursue areas of the hypersonics program that would be relevant to maritime applications. (DARPA, 2003a) DARPA/USAF FALCON Program The FALCON program objectives are to develop and demonstrate technologies that will enable both near-term and far-term capability to execute time-critical, global reach missions. Near-term capability will be accomplished via development of a rocket boosted, expendable munitions delivery system that delivers its payload to the target by executing unpowered boost-glide maneuvers at hypersonic speed. This concept called the Common Aero Vehicle (CAV) would be capable of delivering up to 1,000 pounds of munitions to a target 3,000 nautical miles down-range. An Operational Responsive Spacelift (ORS) booster vehicle will place CAV at the required altitude and velocity. The FALCON program will develop a low cost rocket booster to meet these requirements and demonstrate this capability in a series of flight tests culminating with the launch of an operable CAV-like payload. Far-term capability is envisioned to entail a reusable, hypersonic aircraft capable of delivering 12,000 pounds of payload to a target 9,000 nautical miles from CONUS in less than two hours. Many of the technologies required by CAV are also applicable to this vision vehicle concept such as high lift-to-drag technologies, high temperature materials, thermal protection systems, and periodic guidance, navigation, and control. Initiated under the Space Vehicle Technologies program, and leveraging technology developed under the Hypersonics program, FALCON will build on these technologies to address the implications of powered hypersonic flight and reusability required to enable this far-term capability. The FALCON program addresses many high priority mission areas and applications such as global presence, space control, and space lift. (DARPA, 2003b) REFERENCES Published AFRL (Air Force Research Laboratory). 2003. Technology Programs. Available at http://www.pr.afrl.af.mil/technology.htm. Accessed on December 23, 2003.

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Evaluation of the National Aerospace Initiative Boeing. 2003. Rocket Based Combined-Cycled Engine. Available at http://www.boeing.com/defense-space/space/propul/rbcc.html. Accessed on December 23, 2003. CAS (Committee on Armed Services, House of Representatives). 2003. National Defense Authorization Act for Fiscal Year 2004. Report of the Committee on Armed Services, House of Representatives on H.R. 1588. Available at http://armedservices.house.gov/billsandreports/108thcongress/H1588RAM.pdf. Accessed on January 13, 2004. DARPA (Defense Advanced Research Projects Agency). 2003a. Force Application and Launch from CONUS (FALCON). Available at http://www.darpa.mil/tto/programs/falcon.html. Accessed on December 23, 2003. DARPA. 2003b. Hypersonic Flight (HyFly). Available at http://www.darpa.mil/tto/programs/hyfly.html. Accessed on December 23, 2003. Granone, J.F., and W.A. Davis. 2000. Anti-missile Systems Should Not Be Rushed: Emerging Technologies Offering New Ways to Defeat Ballistic-Missile Attacks. Available at http://www.nationaldefensemagazine.org/article.cfm?Id=216. Accessed on December 23, 2003. Hobbyspace. 2003. Launch & Propulsion Systems, Scramjet & Other Airbreathing Propulsion. Available at http://www.hobbyspace.com/Links/LaunchPropulsion2.html. Accessed on December 23, 2003. IHPTET (Integrated High Performance Turbine Engine Technology). 2003. IHPTET Virtual Library: A Word About IHPTET. Available at http://namis.alionscience.com/virtual/Ihptet/about_IHPTET.htm. Accessed on December 23, 2003 Jackson, T. 2003. Hypersonic technology scramjet engine reaches major milestone. AFRL Horizons. Available at http://www.afrlhorizons.com/Briefs/Dec01/PR0102.html. Accessed on December 23, 2003. Kennedy, K., and S. Nash. 2003. Computational Hypersonic Scramjet Technology Enhancements for Long-Range Interceptor Missile. DoD High-Performance Computing Modernization Program. FY2004 Challenge Project Abstracts. U.S. Army, Army Aviation and Missile Command. Available at http://www.hpcmo.hpc.mil/Htdocs/Challenge/FY04/4.html. Accessed on December 23, 2003. NASA. 1999. NASA Dryden Flight Research Center Photo Collection, Photo ED99-45243-01. Available at http://wwwdfrc.nasa.gov/gallery/photo/index.html. Accessed on December 23, 2003. NASA. 2002a. NASA Developing Hypersonic Technologies; Flight Vehicles Only Decades Away. NASA Photo Release No. 02-182, July 22. Available at http://www1.msfc.nasa.gov/NEWSROOM/news/photos/2002/photos02-182.html. Accessed on December 23, 2003. NASA. 2002b. NASA Developing Hypersonic Technologies; Flight Vehicles Only Decades Away. NASA News Release No. 02-182, July 22. Available at http://www1.msfc.nasa.gov/NEWSROOM/news/releases/2002/02-182.html. Accessed on December 23, 2003. NASA. 2003a. Next Generation Launch Technology (NGLT) News–X43-A Website. Available at http://www.ngltnews.com/x43a.html. Accessed on December 23, 2003. NASA. 2003b. Hypersonics. Available at http://www.spacetransportation.com/ast/hypersonics.html. Accessed on December 23, 2003. NASA 2003c. Turbine-Based Combined Cycle (TBCC) Revolutionary Turbine Accelerator (RTA) Project. Available at http://tbcc.grc.nasa.gov/index.shtml. Accessed on December 23, 2003. NASA. 2003d. Next Generation Launch Technology (NGLT) News–TBCC/RTA. Available at http://www.ngltnews.com/tbcc.html. Accessed on December 23, 2003. Orton, G.F. 2002. Air-Breathing Hypersonics Research at Boeing Phantom Works. Abstract available at http://hypersonic2002.aaaf.asso.fr/papers/17_5251.pdf. Accessed on December 23, 2003. Pratt & Whitney. 2003. Flight-Type Scramjet Completes Historic Test Series. Press release. Available at http://www.pw.utc.com/pr_071403.asp. Accessed on December 23, 2003. Pratt & Whitney. 2004. Air Force Selects Pratt & Whitney and Boeing Team for the Scramjet Flight Demonstrator Program. Available at http://www.pratt-whitney.com/pr_011304.asp. Accessed on March 25, 2004. U.S. Air Force. 1999. Air Force Successfully Launches ait-2 Rocket. USAF Press Release. Available at http://www.losangeles.af.mil/SMC/PA/Releases/1999/nr99091501.htm. Accessed on December 23, 2003. U.S. Navy. 2003. FEDBIZOPS. Special Notices. April 2003—China Lake and Point Mugu. Available at https://contracts.nawcwd.navy.mil/cbdsp_p04.htm. Accessed on December 23, 2003. Unpublished McDaniel, J. 2004. Single-Engine Demonstrator. Jay McDaniel response to a committee question, received by staff on January 14. Sega, R. 2003. National Aerospace Initiative: NRC Briefing. Briefing by Ron Sega, DDR&E, Office of the Secretary of Defense, to the Committee on the National Aerospace Initiative. August 6.