PaperNo.IAF-00-V.4.01 NASA'sHyper-XProgram V. Rausch andC. McClinton Hyper-XProgramOffice NASALangleyResearchCenter Hampton,Virginia and J. Sitz andP.Reukauf Hyper-XFlightProjectOffice NASADrydenFlightResearchCenter Edwards,California 51st International Astronautical Congress 2-6 October2000/Riode Janeiro, Brazil For permission to copy or republish, contact the International Astronautical Federation 3-5 Rue Mario-Nikis, 75015 Paris, France NASA'S HYPER-X PROGRAM Vincent L. Rausch and Charles R. McClinton National Aeronautics and Space Administration. l_angley Research Center, Hampton, Virginia 2368 I Joel Sitz and Paul Reukauf National Aeronautics and Space Administration, Dryden Flight Research Center, Edwards, California 93523 ABSTRACT HYPULSE LaRCHYpersonic PULSE Facility LaRC NASA Langley Research Center This paper provides an overview of the objectives and NASA National Aeronautics and Space Adminis- status of the Hyper-X program which is tailored to move tration hypersonic, airbreathing vehicle technology from the NASP National Aero-Space Plane laboratory environment to the flight environment, the TBCC Turbine-Based Combination Cycle last stage preceding prototype development. The first X-43 Hyper-X research vehicle Hyper-X research vehicle (HXRV), designated X-43, is being prepared at the Dryden Flight Research Center for INTRODUCTION flight at Mach 7 in the near future. In addition, the asso- ciated booster and vehicle-to-booster adapter are being NASA initiated the joint LaRC and DFRC Hyper-X prepared for flight and flight test preparations are well Program in 1996 to advance hypersonic airbreathing underway. Extensive risk reduction activities for the first propulsion and related technologies from the laboratory flight and non-recurring design for the Mach 10 X-43 to the flight environment (ref. l, 2). The program goal (3rd flight) are nearing completion. The Mach 7 flight of is to verify and demonstrate the experimental tech- the X-43 will be the first flight of an airframe-integrated niques, computational methods and analytical design scramjet-powered vehicle. tools for hypersonic, hydrogen-fueled, scramjet-pow- ered aircraft. Accomplishing this goal requires flight ACRONYMS data from a scramjet-powered vehicle (fig. I). Because of the highly integrated nature of scram jet-powered AEDC Air Force Arnold Engineering and vehicles, the complete vehicle must be developed and Development Center tested, as propulsion verification cannot be separated AETB Alumina-enhanced thermal barrier tiles fi'om other hypersonic technologies. AHSTF LaRC Electric Arc Heated Scram jet Test Facility This technology is required for any efficient hypersonic AOA Angle-of-attack cruise vehicle, and has the potential tosignificantly reduce CDR Critical design review the cost and increase the mission flexibility of future U.S. CFD Computation fluid dynamics single/two-stage-to-orbit access-to-space systems. DFRC NASA Dryden Flight Research Center DFX Dual-fuel experimental engine (full-scale, The X-43 is small to minimize development cost and partial-width/length engine) the cost of boosting it to the test condition. In addition, GNC Guidance, navigation and control to reduce design time and cost, the vehicle is based on HSM HYPULSE scram jet model (full-scale, an existing Mach 10 cruise, global-reach mission con- partial-width/length engine) figuration (ref. 3), and the extensive NASP database. 8' HTI" LaRC 8' high temperature wind tunnel Figure 2 depicts the 12-foot long X-43 mounted on the HXEM Hyper-X engine model (full-scale, partial- Pegasus-based Hyper-X launch vehicle (HXLV), which width/length engine) iscarried to the launch point by the DFRC B-52. HXFE Hyper-X flight engine (full-scale, dedicated toground testing) The X-43 will be boosted to approximately 95,000 feet HXLV Hyper-X launch vehicle for the two Mach 7tests and 110,000 feet for the Mach HXRV Hyper-X research vehicle (X-43) 10 test. The fully autonomous X-43 vehicles will fly preprogrammed 700 to 1000-mile, due-West routes in the Western Test Range off the California coast (figure Copyright © 2000 by the American Institute of Aeronautics and 3). Test data will be transmitted to aircraft and ground Astronautics, Inc. No copyright is asserted in the United States under stations. The X-43, the vehicle-to-booster adapter, and Title 17, U.S. Code. The U.S, Government has aroyalty-free license the HXLV are in final check-out at DFRC. The first X- to exercise all rights under the copyright claimed herein for Govern- mental purposes. All other rights are reserved by the copyright owner. 43 flight is scheduled for late 2000/early 2001. 1 American Institute of Aeronautics and Astronautics The following sections present a brief overview of the in the HYPULSE facility (ref. 6). In addition, tests design phase, vehicle development, vehicle ground were performed early in the program to verify inlet tests, and Hyper-X technology. Tests at true flight pres- starting with the articulating cowl door. sure and enthalpy of the full-scale, powered X-43 model in a Mach 7 wind tunnel at LaRC are described. A preliminary aerodynamic database was developed in Finally, the connection between the flight tests and 1996 from results of quick-look experimental programs. technology development for future hypersonic air- These tests were performed using 8.3ck and 3.0% scale breathing engine-powered vehicles is examined. models of the X-43 and the HXLV at Mach numbers of 0.8-4.6, 6 and i0. The aerodynamic database includes CONCEPTUAL/PRELIMINARY DESIGN boost, stage separation, research vehicle powered flight (with propulsion data) and unpowered flight back to The conceptual design for the Hyper-X was completed subsonic speeds. Figure 4 illustrates the range of tests in May 1995 (ref. 3) and the preliminary design was used to develop the Hyper-X aerodynamic database. completed in October 1996 (ref. 1,3). The HXLV con- The final aerodynamic database uses the results from tract was awarded to Orbital Sciences Corporation in over 5808 tests in 10 facilities of 16 models ranging February 1997 and the HXRV contract to Micro Craft, from 3.0% to 100% scale (when including powered test Inc. (with Boeing, GASL and Accurate Automation data from the 8' H'I-T). Corp. as team members) in March 1997. The Hyper-X Program operates as a closely allied government-indus- Other work leading up to the fabrication of the first try team. Integrated product teams for vehicle develop- Hyper-X research vehicle included control law devel- ment and technology and/or discipline teams for tech- opment, evaluation of trajectories, development of nology and flight test activities perform day-to-day pro- aerothermal loads and design of the engine structure. gram activities. Measurements and instrumentation for the Hyper-X The X-43 was scaled photographically from the Mach flight test are selected to: 10 cruise global-reach concept (ref. 3). Scaling the con- • Determine overall vehicle performance (attitude, figuration external lines, with the exception of details rates and position) such as leading edges, enabled the utilization of exist- • Monitor vehicle systems for health/safety ing databases, as well as rapid convergence to a con- • Identify failure modes trollable flight research vehicle with low trim drag • Evaluate local flow phenomena penalty. The scramjet flowpath was re-optimized to • Validate design methods (propulsion, aerodynamic, ensure engine operability and vehicle acceleration. For thermal, structures and controls) the single-Mach operating flight condition, the Hyper- X engine geometry is fixed, except for the inlet cowl, The instrumentation approach utilizes a limited quanti- which is closed to protect the engine during boost and ty of proven reliable measurements (pressure, tempera- descent. Although there are differences between the ture, and strain gage). Off-the-shelf data system com- reference Math 10 vehicle and Hyper-X scramjet ponents are utilized to process and telemeter measure- engine flowpaths, demonstration of the Hyper-X pre- ments. The primary measurement is vehicle accelera- dicted performance will be validation of the design pro- tion. Of the 503 measurements, about 200 are Vehicle cess (ref. 4). Management System digital and about 300 are analog parameters (194 pressure, 107 temperature, and 13 Wind tunnel testing commenced in early I996 to verify strain gauge). About 160 of the surface measurements the engine design, develop and demonstrate flight provide propulsion flowpath-related data and 100 pro- engine controls, develop aerodynamic data bases for vide aerodynamic data. stage separation, control law and trajectory develop- ment and support the flight research activities. Mach 7 Vehi¢!¢ Development and Flight Tests engine performance and operability were verified in reduced dynamic pressure tests of the DFX (dual-fuel The HXLV and HXRV CDR's were held in December experimental) engine in the NASA LaRC Arc-Heated 1997 and February 1998, respectively. Scramjet Test Facility (AHSTF, ref. 5). During this same time, preliminary experimental results for the Hyper-X Launfh Vehicle Development Math 5 and 10 scramjet combustor designs were obtained using the direct-connect combustor module rig Orbital Sciences Corporation activities focused on con- and an existing semi-direct connect combustor model figuration and systems definition, structural stiffness, 2 American Institute of Aeronautics and Astronautics controllawrefinementrt,ajectoruyncertainatynalysis, ture is copper which is primarily heat-sink cooled for andaerodynamaicndthermaal ssessmenftosrthe the short-duration scramjet test. Water cooling is Hyper-Xtrajectorwyhichisdepresswedhencompared included for the cowl and sidewall leading edges. An toanormaPl egasutsrajectoryA. jointstudybythe articulating cowl leading edge section closes the flow- contractorasndthegovernmenetstablishetdhatthe path, protecting the engine internal surfaces during separatiocnonditionfortheMach7flightshouldbeat boost and descent after the scramjet test. Figure 9 dynamipcressu=re1066psf(+/-50),Mach=7.06(+/- shows the first engine, a Mach 7 flight spare, which is 0.1),andflightpathangle=2.0(+/-0.2)degreesA. dedicated toground testing in the LaRC 8' HTT. Monte Carlo analysis (accounting for uncertainty in B- 52 drop conditions, atmospheric properties and winds, Engine control laws were designed to: determine fuel inertial navigation unit, flight controls, aerodynamic requirements; provide timing for inlet open/close and database, rocket motor lsp, propellant load and burn fuel and ignitor sequences; actively monitor vehicle time, and vehicle mass properties) established that acceleration; and provide closed loop monitor/control these conditions could be achieved. It also revealed that of inlet-isolator and vehicle acceleration performance. the flight path angle is the most critical of these trajec- For the first test the powered segment of the flight will tory aim point parameters. be at nearly constant angle-of-attack. The target fuel flow will be established based on estimated air mass The first HXLV (fig. 5) has been delivered to DFRC capture. The fuel sequence includes ignition using a and final preparations for flight are underway. The sec- silane-hydrogen mixture, transition to hydrogen only ond HXLV is also at DFRC and is undergoing final fueling, and ramp-up to full fuel flow rate. The HXFE preparations prior to its delivery to the government. engine control laws were verified through an extensive Orbital is also responsible for vehicle integration and series of 8' HTT tests. launch support activities. In addition, Orbital performed some structural testing tasks for the HXRV contractor. HXFE (3round Testing (Ref. 7) HJ_per-X Research Vehicle Development (X-43) A 10-month test series of the Hyper-X Flight Engine (HXFE) was completed in June 2000, in the LaRC 8- The primary Micro Craft activities for the X-43 and Foot High Temperature Tunnel (fig. 10). vehicle-to-booster adapter included design, materials and systems procurement, fabrication, and testing. The test objectives were three-fold. First, the results are a major part of the Math 7 aerodynamic and propulsion The vehicle structural design and final systems layout are database for the X-43. This test series included inlet presented in figure 6. The vehicle structure consists of and engine operation with a fully integrated forebody 4140 heat-treated steel keels and side longerons; titanium, and aftbody flowpath with active propulsion subsystem or 4130 steel bulkheads; and 4130 steel, 301 stainless or control which included closed-loop engine feedback. 6061-T6 aluminum skins. Thermal protection consists of The data will be used to both correlate with the X-43 alumina-enhanced thermal barrier tiles (AETB-12) and flight data and compare with other Hyper-X ground- carbon-carbon wing and nose leading edges. The majori- test data. Furthermore, data were obtained for two seg- ty of the wings and tails are Constructed from high-tem- ments of the flight profile that have not been acquired perature, Haynes-230 alloy. The nose is tungsten. The elsewhere: the force and moment increments due to first X-43 is undergoing final tests and preparations at opening the cowl door and due to fuel combustion. This DFRC (fig. 7). The second X-43 is undergoing systems provided data for comparison with previously comput- tests at Micro Craft inTullahoma, TN. ed aero-propulsive increments used to define vehicle control laws for the scramjet portion of the flights. Fur- Verification of the structural stiffness of the mated thermore, the data will also provide insight into the pre- HXLV/adapter/X-43 stack necessary for HXLV flight dictive capabilities of CFD codes and other tools used control requirements, required extensive analyses and in the design and analysis of airframe-integrated scram- tests. Modal tests in early 1999 validated the predic- jet flowpaths. tions (fig. 8). Additionally, the flight controls team has identified and implemented relatively simple solutions Second, important component and systems verifications (filters) to reduce the bending modal limit. were obtained during this test, primarily on the engine mechanical and thermal design, the associated fluid The flight engine is a heavy, robust design similar to systems, and the propulsion subsystem control soft- wind tunnel flowpath models. Most of the engine struc- ware. Engine hardware components that were verified 3 American Institute of Aeronautics and Astronautics includecowl-dooarctuationc,owlandsidewall lead- out. At this point, minor modifications were made to ing-edge cooling, and the structural integrity of the the lightoff/transition part of the flight fuel sequence engine during the critical part of the flight (from post- that improved lightoff and flameholding. stage separation to completion of the fueling sequence). Altitude Excursions: The nominal test point for the scramjet portion of the X-43 flight is at two-degrees Third, this test series furthered the development of angle of attack and zero-degree sideslip. In order for the technolo_' capabilities that will be required to perform flight control computer to be able to correct vehicle atti- ground tests of hypersonic airbreathing propulsion sys- tude when it is not at the nominal angle of attack, esti- tems that are fully integrated with hypersonic vehicles. mates of the forces and moments at angles of attack other than two degrees are required. Originally, these In addition to these objectives, data were also acquired increments were obtained using CFD and analytical to understand the flow environment at various places methods. A series of runs during the HXFE test was used including the forebody, external nozzle, wing-root gap, to quantify engine air mass capture and engine perfor- and aftbody at true Mach 7 flight conditions. mance and operability at off-nominal conditions. Angle- of-attack excursions were performed at zero and four Fourteen successful unfueled runs were performed with degrees, providing force and moment increment data due the HXFE. Six of these runs characterized the inlet to cowl-door opening and due to fueling. Comparisons flowfieid pifine via rake survey data-fo(three angles of wqtK-th_-existing database humb-ers are Very good. attack, including two dynamic pressures at flight angle Sideslip angles of 6ne and three degrees (the largest of attack, and the three boundary-layer trip options at known sideslip angle at which a scramjet has ever been flight dynamic pressure and flight angle of attack. The teste_) were also performed wiih no sign_f[rant d_ra_a, remaining eight unfueled runs were used to address tion in engine performance and operability. Data from cowl-door actuation, including effects of cowl door these tests compared favorably with CFD solutions, con- actuation speed, quantification of force and moment firming predicted powered lateral stability. increments at different angles of attack and dynamic Cowl Actuation at Flight-like Heat Loads: The pressures, and cowl door actuation capability following HXFE performed a high-risk engine heat-soak run that extended exposure to simulated flight heat loads. simulated the heating that the X-43 scramjet engine will encounter during its ascent on the booster to the test Forty successful fueled runs were made with the HXFE point. The objective of the run was flight risk reduction in which engine performance and operability were of by determining if that much heat applied to the engine primary interest. Among the details addressed by these had any adverse effect on cowl door actuation. Based on runs were the thermal effects on the boundary-layer calculations performed by the engine manufacturer entering the engine, dynamic-pressure effects, angle-of- (GASL, Ronkonkoma, NY), subjecting the engine to 25 attack effects, data repeatability, effects of boundary- seconds of Mach 7 enthalpy tunnel flow at a dynamic layer trips, effects of sideslip, active fuel-control refine- pressure of 1280 psf equates to about the same amount ment, improving engine light-off and transition to of heating that it will encounter during the boost to the hydrogen-only fueling, ability to restart the inlet and scramjet test point. During the run, the model was in the relight the engine following an engine unstart, and flow 26 seconds before the cowl door was commanded ablative forebody TPS effects on engine performance open. It opened in less tl_at 0.5 seconds to the full-open and operability. In addition, a post-flight ground test position with no problems, as planned. comparison run that will simulate the flight conditions and fueling sequence that existed during the flight as In addition, two other sets of runs were performed to accurately as possible is planned. address post-flight scramjet/vehicle development: Engine Unstart/Restart Capability: The HXFE suc- A number of significant firsts were accomplished dur- cessfully demonstrated restart capability of an airframe- ing this test series: integrated scramjet engine. This objective was met by Fuel Delivery Refinement: Fueled tests that were purposely causing the HXFE inlet to unstart (via excess performed late in 1999 indicated that there was a con- fueling), followed by rapidly throttling-down the fuel, cern about the engine lightoff and the transition from restarting the inlet flow by actuating the cowl door, and silane-piloted fueling (used to establish a robust flame) re-igniting the engine. The restart process was achieved to hydrogen-only fueling. In one case, the engine in 1.76 seconds and the data suggests that it could be flamed out, and in two other instances, the engine per- achieved significantly faster. In addition to demonstrat- formance data during transition to hydrogen-only fuel- ing engine restart, the analysis of force and moment data ing indicated that the engine was very close to flaming will provide valuable insight into vehicle dynamics. 4 American lnstitutc of Aeronautics and Astronautics Abla.ljv¢ TPS Effects: The HXFE was also used to research objectives include evaluation of a Flush Air verify the use of a new Boeing lightweight ablator ther- Data System and most importantly, development of mal protection system (TPS). TPS survivability during flight test techniques applicable to highly integrated, the Mach 7 1000-psf dynamic pressure (both extremes airbreathing engine powered hypersonic vehicles. for this TPS), 22-second run was very good. The HXFE had a good lightoff and maintained combustion In addition to the 500 instrumentation parameters on throughout the runs and did not appear to be affected the X-43,700 parameters are included on the HXLV. by the ablator. This is the first time this type of ablator The HXLV instrumentation monitors approximately material has been tested with an operating engine. The 400 guidance, navigation, and control parameters and second run was the first time that the TPS was re-test- 300 acceleration, discrete, and power system informa- ed, providing data to address reusability of the TPS. tion analog sensors, including information on the stage separation sequence. The data will be relayed to Voli_tation Tests the DFRC mission control room and to LaRC for recording and real time display of selected parame- A large number of preflight tests are being conducted ters. It will also be recorded at the Navy's Pt. Mugu at DFRC including a full set of subsystem and system facility and by two Navy P-3 aircraft. To reduce the validation tests utilizing an aircraft-in-the-loop simula- risk of loss, scramjet engine data will be rebroadcast tion (fig 7). The X-43 and adapter will then be inte- at regular intervals. grated with the HXLV and a series of integration tests will be performed. In parallel, the B-52, the X-I5 Real time video from the B-52 will monitor the captive pylon, and the HXLV to pylon adapter will be modi- carry portion of the flight as well as the initial drop of fied for the Hyper-X application and interface testing the stack. The F-!8 photo chase will provide video for will be completed. Combined systems tests, performed the initial drop from the B-52, the rocket ignition with all avionics systems, communication systems, sequence, and the first portion of the boost trajectory. telemetry systems, and representative space position- In addition, two cameras are mounted in the vehicle-to- ing systems operational will be conducted to ensure booster adapter to record the stage separation. A rawin- there is no significant electromagnetic interference sonde balloon will be used to measure upper atmo- between systems and to verify the transmission and spheric pressures, temperatures, and winds near the reception of data. Taxi and flight tests of the B-52 with location and altitude of the scramjet test. These data the stack attached will be used to clear the captive will be used to correct the X-43 performance calcula- carry flight envelope for flutter, exercise the tracking tions to standard day conditions and validate the inertial and data reception capabilities of the test range, and measurement system information. provide operational rehearsals. Flight test operations will be conducted in accordance X-43 Fli_ht Tests with established DFRC practices. The flight approval process will include a Flight Readiness Review and an The flight test objectives include: authorization to proceed from the Airworthiness and (1) acquisition of flight data to document the perfor- Flight Safety Review Board. A large portion of these mance and operability of airframe-integrated hydro: reviews is allotted to flight safety. In addition, factors gen-fueled, dual-mode scram jet-powered research affecting mission success will also be considered. vehicles at Mach 7and 10; Finally, prior to each flight, technical and crew briefin- (2) demonstration of controlled powered and unpow- gs will be conducted. ered hypersonic aircraft flight; and (3 acquisition of flight data to validate/update the The first flight is scheduled to occur in late 2000/early computational methods, prediction analyses, and 2001 with the following flights scheduled for mid- test techniques that comprise a set of methodologies 2001 (Mach 7) and early 2002 (Mach 10). During each for the design of future hypersonic cruise and space of these flight tests, the B-52 will carry the stack to the access vehicles. launch point where it will be dropped, the rocket motor ignited, and a climbing due west boost trajector 3"flown Specific flight operations objectives are to safely to the stage separation point. At this point, the HXRV launch the stack from the B-52 (fig. I 1), successfully will go through the sequence illustrated in figure 12. separate the X-43 from the adapter at the appropriate The HXRV will not be recovered but telemetered test test conditions, and obtain the desired test data in all data will be received almost to splash down in the areas of the flight envelope that are of interest. Flight Pacific Ocean. 5 American Institute of Aeronautics and Astronautics Hyper-X Technology database uncertainty. The extensive aerodynamic database also provides background for quick validation The Hyper-X program technology focus is on four of design methods, and identification of error sources if main objectives required for practical hypersonic flight. the flight data does not agree with the design database. • Hyper-X (X-43) vehicle design and flight test risk reduction Additionally, a large risk reduction activity including • Flight wdidation of design methods wind tunnel and mechanical tests, CFD analysis, aerody- • Design methods enhancement namic database development, 6+6+3 degree-of-freedom • Future vehicle systems development simulation, and Monte Carlo uncertainty analyses was pursued for the research vehicle stage separation (fig. 14). D.g.s.Jg.0LRecent Hyper-X flight vehicle design activ- ities have focused on the Mach 10 vehicle engine flow- _;_;rarrljet Testine Facilities. Models. and Flight path optimization, loads definition/minimization and Facilities and models utilized by the Hyper-X vehicle and engine thermal/structural redesign. Assess- Program for scramjet engine flowpath and propulsion-air- ments of the Mach 7design at the higher Mach 10 ther- frame integration development and flight test risk reduc- mal loads concluded that only leading edges, the engine tion ,'ire summarized in Table 2. Details of these facilities cowl flap, and a few engine parts require modification. and use in wind tunnel tests are discussed inreferences 5, Alternate materials and/or limited cooling to ensure ther- 6, 10, 12, and 13.Unlike aerodynamic tests, scramjet tests mal survival for the Mach l0 vehicle wing, tail, and require high-temperature (enthalpy) and high-pressure air body leading edges, and engine parts are being studied. or "test gas". In these facilities, the test gas is heated by several means: electric arc, combustion, or reflected Flight Test Risk Reduction: Risk reduction shock. For each of these facilities the test gas contains includes detailed analysis and testing to assure the some contamination relative to the flight environment. flight test is successful. It includes all phases of the The impact of the contamination on performance adds flight (fig. I1) and all disciplines. This risk reduction some uncertainty to the predicted flight performance and activity also serves to refine and can lead to significant engine operability (ignition, flameholding, inlet starting improvements in the design tools. Successful demon- and inlet isolator effectiveness). In addition, some of these stration of the scramjet-powered vehicle's predicted facilities do not fully simulate the flight dynamic pressure performance will validate the use of these tools in the (listed intable 3). A shock tunnel (HYPULSE facility, ref. design process. Experimental propulsion flowpath, 6) is also utilized for Hyper-X Mach 7 engine tests, pro- aerothermodynamic and propulsion-airframe integra- viding clean-air test gas at dynamic pressures in excess of tion tests play akey role in this activity. 1000 psf for Mach 7 full scale flight simulation, albeit with short test times. Testing the engine at Mach 7 in AcrocJynamic Facilities. Models and Flight Scaling: HYPULSE also provides a close comparison with long The primat 3' aerodynamic wind tunnels and models uti- duration tests to verify the HYPULSE reflected shock tun- lized for the X-43, HXLV, stage separation and FADS nel testing methods before the facility is used to determine database development are listed in table 1. Details of the Mach 10scramjet engine performance. these facilities are presented in references 8 and 9 and use of these facilities in the Hyper-X program is dis- Flight scaling of performance and operability from cussed in references 10 and 11. The X-43 models wind tunnel data is accomplished using a slightly dif- include 12-inch (8.3% of full scale), 18-inch (12.5%) ferent approach than used for aerodynamic database and 30-inch (20.8 % of full scale) steel models of the development. Design methods, including analytical and research vehicle, a 33%-scaled model of the research CFD-based methods (see ref. 4) can model, to some vehicle forebody, an 80% scaled model of the vehicle degree, both the wind tunnel test gas and the flight nose with a 100% scale FADS system, and the full-scale environments. These prediction methods are verified by nose-to-tail flowpath used in the 8' HTT. comparison with multiple ground tests of the X-43 engines. Flight scaling is accomplished by using these The results from these aerodynamic wind-tunnel tests methods to predict the flight performance for the form the basis of the design aerodynamic database uti- expected flight conditions (ref. 11). lized in the determination of scramjet thrust require- ments, and for flight simulation. In addition, the final Flight Va.lid:0t on of DesiGn Methods aerodynamic database model is verified by comparison with CFD predictions for the flight conditions (such as A primary Hyper-X program goal is flight verification fig. 13). This process decreases the design aerodynamic of design methods for scramjet propulsion, hypersonic 6 American Institute of Aeronautics and Astronautics aerodynamaicnsdpropulsion-airfrainmteegratioTnh.is envisioned to include a reusable flight research vehicle. isrequiretdodevelocponfidencinepredictecdapabili- An air-launched configuration is currently being studied tiesoffuturehypersonviechiclesystems. by Boeing under a joint NASA LaRC, Marshall Space Flight Center, and Glenn Research Center study (fig 15). Propulsion-airfrainmteegratiodnesign methods, unlike aerodynamic and propulsion methods, have not been Other long-term technology development is being adequately ground-test verified due to the limited directed toward the following: nature of appropriate data. This limitation was • Alternate engine cycles (ref. 16-17); addressed by the wind tunnel test program using the • Plasma aero, magneto-hydrodynamics, virtual inlet Hyper-X flight engine (fig. 10) and the complete X-43 power generation (ref. 18); flowpath in the 8' HTT (table 2). The next step is to • System studies to refine existing or to identify new validate the design methods with the X-43 flight data. concepts and missions for hypersonic airbreathing Some issues expected in flight (vis-a-vis wind tunnel) reusable vehicles; validation include: • Hypervelocity scramjet engine technology: Mach • Low free stream turbulence effects on fuel mixing, numbers of 14- 20 (ref. 19). shock-induced boundary layer separation, and boundary layer transition control; SUMMARY • Full total enthalpy effects on slender-body, hyper- sonic, wind-tunnel based aerodynamic performance; This paper provided an overview of the Hyper-X pro- • Clean-air test gas effects on ignition, flameholding gram. The program is poised to move hypersonic air- and flame propagation; breathing technology to the level required for serious • Unknowns in propulsion-airframe integration. consideration for future systems. The Hyper-X flight test program is making the final preparations for the Method Enhancements first Mach 7, X-43 flight in late 2000/early 2001. Extensive risk reduction activities for the first flight are Scramjet engine and scram jet-powered vehicle design complete, and non-recurring design for the Mach 10 require a matrix of highly integrated design tools vehicle and pre-flight test preparation are nearly com- encompassing engineering and higher order CFD based plete. This paper also has addressed how the flight test analysis methods (ref. 4) and specialized experimental integrates with the overall technology development facilities and measurement systems (ref. 14). Success- effort and future development plans. ful development of hypersonic airbreathing engine- powered vehicles requires continued refinement of these design tools. Part of the current program focus on REFERENCES parametric tests and analysis around the Math 5, 7 and 10conditions is to develop these design systems for the 1. Rausch, V. L.; McClinton, C. R.; and Crawford, J. X-43 configuration. These design systems will soon be L.: Hyper-X: Flight Validation of Hypersonic Air- completed and in place to characterize and optimize the breathing Technology. ISABE 97-7024, Sept. 7-12, X-43 class engine for the Mach 4 to 10 dual mode 1997, Chattanooga, TN. scram jet required for future vehicle development. 2. Rausch, V. L.; McClinton, C. R.; and Hicks, J. W.: NASA Scramjet Flights to Breath New Life into Hyper-X Phase II and Beyond (Future Vehicle Design) Hypersonics. Aerospace America, July 1997. 3. Hunt, J. L., Eiswirth, E. A., NASA's Dual-Fuel Air- This technology area represents the long-term look at breathing Hypersonic Vehicle Study. AIAA CP-96- future systems. The Hyper-X program, as discussed in 4591,7th International Space Planes and Hyperson- detail in reference 15, is planned as a two-phase pro- ics Systems &Technology Conference, Nov. 1996. gram. Phase I emphasis is on the Mach 5 - 10, dual- 4. Hunt, J. L.; McClinton, C. R.: Scramjet Engine/Air- mode scramjet operating speed range. Phase II is not frame Integration Methodology. AGARD Future funded, but studies leading to a Phase II are progressing. Aerospace Technology Conference, Paper C35, Phase II is intended to provide flight validation of critical Palaiseau, France, April 14-16, 1997. technologies for hypersonic aircraft or access-to-space 5. Guy, R. W.; Rogers, R. C; Pulster, R. L.; Rock, K. vehicles by focusing on operation from takeoff into the E.; and Diskin, G. S.: The NASA Langley Scramjet scramjet operating speed range (Mach 0 - 7). This Test Complex. AIAA 96-3243, 32nd AIAA includes operation on and transition from the low speed /ASME/SAE/ASEE Joint Propulsion Conference, engine to the dual-mode scramjet. Phase 1I is currently Lake Buena Vista, FL, July 1-3, 1996. 7 American Institute of Aeronautics and Astronautics 6. BakosR, .J.;CastrogiovannAi,.;Calleja,J.F.; breathing Propulsion Testing. AIAA CP-96-2197, NucciL,.;andErdosJ,.I.:ExpansioonftheScram- 19th AIAA Advanced Measurement and Ground jetGroundTesEt nvelopoeftheHYPULSEFacili- Testing Technology Conference, June 1996. ty.AIAA96-4506A,IAA7thInternationSalpace 13. Roffe, G.; Bakos, R. J.; Erdos J. I.; and Swartwout, PlanesandHypersoniScystemasndTechnology W.: The Propulsion Test Complex at GASL. ConferencNeo,rfolkV,A,Nov.1996. ISABE 97-7096, Sept. 1997. 7. HuebneLr,.D.;RockK, .E.;Witte,D.W.;Ruf,E. 14.Rogers, R. C.; Capriotti, D. P.; and Guy, R. W.: G.;and Andrews, E. H.: "Hyper-X Engine Testing Experimental Supersonic Combustion Research at in the NASA Langley 8-Foot High Temperature NASA LaRC. AIAA-98-2506. 20th AIAA Tunnel." AIAA Paper 2000-3605, July 2000. Advanced Measurement and Ground Testing Tech- 8. Miller, C. G., III: Langley Hypersonic Aerodynam- nology Conference, July, 1998. ic/Aerotherm_v3ynamic Testing Capabilities--Present 15.Hunt, J. L. and Couch, L. M.; Beyond Hyper-X, and Future. AIAA CP-90-1376, AIAA 16th Aerody- Space '98. Sixth ASCE Specialty Conference, April namic Ground Testing Conference, June 1990. 26-30, 1998. 9. Penaranda, F. E.; and Freda, M. S.: Aeronautical 16.Pegg, R. J.; Couch, B. D.; and Hunter, L. G.: Pulse Facilities Catalogue, Vol. 1- Wind Tunnels. NASA Detonation Engine Air Induction System Analysis. RP-1132, Jan. 1985. AIAA 96-2918, 32rid AIAA/ASME/SAE/ASEE 10. McClinton, C. R.; Holland, S. D.; Rock, K. E.; Joint Propulsion Conference, July I-3, 1996. Engelund, W. C.; Voland, R. T.; Huebner, L. D.; 17.Bussing, T. R. A.; and Pappas, G.: An Introduction to Rogers, R. C.: Hyper-X Wind Tunnel Program. Pulse Detonation Engines. AIAA 94-0263, Jan. 1994. AIAA 98-0553, Jan. 1998. 18.Gurijanov, E. P.; and Harsha, T.: Ajax: New Directions 1l.McClinton, C. R.; Voland, R. T.; Holland, S. D.; in Hypersonic Technology. AIAA 964609, AIAA 7th Engelund, W. C.; White, J. T.; and Pahle, J. W.: International Spaceplanes and Hypersonic Systems and Wind Tunnel Testing, Flight Scaling and Flight Val- Technologies Conference. Nov. 18-22, 1996. idation with Hyper-X, AIAA 98-2866, June 1998. 19.Erdos, J. I.; Bakos, R. J.; Castrogiovanni, A. and 12.Huebner, L. D.; Rock, K. E.; Voland, R. T.; and Rogers, R. C.; Dual Mode Shock-Expansion/Reflect- Wieting, A. R.: Calibration of the Langley 8-Foot ed-Shock Tunnel. AIAA 97-0560, 35th Aerospace High Temperature Tunnel for Hypersonic Air- Sciences Meeting, Jan. i997. Facility HXLV Stage HXRV BL FADS Separation Control Calibration LaRC 31" 8.3% Mach 10 LaRC 20" 8.3% Mach 6 AEDC VKF-B 80% Mach 6 Polysonic 80% 0.4<M<4.6 BNA Mach 0.2 Preliminary/similar config. Quick look Detailed Benchmarked Table 1. Aerodynamic Wind Tunnel Tests (model scale in % of full scale). 8 American Institute of Aeronautics and Astronautics