Tôi cảm thấy tôi là người Nhật Bản

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Có một câu chuyện hài hước như ri:
Trước đây, hàng hoá Nhật rất kém. Một ông Mĩ vừa hỏng việc vừa phá sản vì mua mấy đồ Nhật. Ông ta vừa hết đất sống vừa ức, liền rút khẩu súng Nhật ra, chĩa vào đầu, bóp cò.
Cạch, súng hổng nổ.
Sau khi bị mấy ổng đen đen vô lý làm mất bao nhiêu công lao, tôi post một bài: acc chat, forum nhà, tên thật(=acc bên đó). Và cộng thêm một câu chào: không bao giờ quay lại đây nữa. Và send.
Nước mắt tràn ly: server báo error, bạn không được quyền gửi bài.
Thế thì tôi lại nhăn nhó hầu chuyện các bác vậy.
Các bác chắc bít hệ máy bay thử nghiệm X chứ. Đây là toàn bộ chúng( chỉ kể những cái bay được)

Bây giờ gõ bài dịch sợ mất công lắm, các bác dịch hộ tui nè:The X-29
Two X-29 aircraft, featuring one of the most unusual designs in aviation history, were flown at the NASA Ames-Dryden Flight Research Facility (soon to be renamed the Dryden Flight Research Center), Edwards, Calif., as technology demonstrators to investigate advanced concepts and technologies. The multi-phased program was conducted from 1984 to 1992 and provided an engineering data base that is available in the design and development of future aircraft.
The X-29 almost looked like it was flying backward. Its forward swept wings were mounted well back on the fuselage, while its canards ­ horizontal stabilizers to control pitch ­ were in front of the wings instead of on the tail. The complex geometries of the wings and canards combined to provide exceptional maneuverability, supersonic performance, and a light structure. Air moving over the forward-swept wings tended to flow inward toward the root of the wing instead of outward toward the wing tip as occurs on an aft swept wing. This reverse air flow did not allow the wing tips and their ailerons to stall (lose lift) at high angles of attack (direction of the fuselage relative to the air flow).
The concepts and technologies the fighter-size X-29 explored were the use of advanced composites in aircraft construction; variable camber wing surfaces; the unique forward-swept wing and its thin supercritical airfoil; strake flaps; close-coupled canards; and a computerized fly-by-wire flight control system to maintain control of the otherwise unstable aircraft.
Research results showed that the configuration of forward swept wings, coupled with movable canards, gave pilots excellent control response at up to 45 degrees angle of attack. During its flight history, the X-29's were flown on 422 research missions 242 by aircraft No. 1 in the Phase 1 portion of the program; 120 flights by aircraft No. 2 in Phase 2; and 60 flights in a follow-on "vortex control" phase. An ad***ional 12 non-research flights with X29 No. 1 and 2 non-research flights with X-29 No. 2 raised the total number of flights with the two aircraft to 436.
Reverse airflow-forward-swept wing vs aft swept wing. On the forward-swept wing, ailerons remained unstalled at high angles of attack because the air over the forward swept wing tended to flow inward toward the root of the wing rather than outward toward the wing tip as on an aft-swept wing. This provided better airflow over the ailerons and prevented stalling (loss of lift) at high angles of attack.
Program History
Before World War II, there were some gliders with forward-swept wings, and the NACA Langley Memorial Aeronautical Laboratory did some wind-tunnel work on the concept in 1931. Germany developed a motor-driven aircraft with forward-swept wings during the war known as the Ju-287. The concept, however, was not successful because the technology and materials did not exist then to construct the wing rigid enough to overcome bending and twisting forces without making the aircraft too heavy.
The introduction of composite materials in the 1970's opened a new field of aircraft construction, making it possible to design rugged airframes and structures stronger than those made of conventional materials, yet lightweight and able to withstand tremendous aerodynamic forces.
Construction of the X-29's thin supercritical wing was made possible because of its composite construction. State-of-the-art composites permit aeroelastic tailoring, which allows the wing some bending but limits twisting and eliminates structural divergence within the flight envelope (i.e., deformation of the wing or breaking off in flight).
In 1977, the Defense Advanced Research Projects Agency (DARPA) and the Air Force Flight Dynamics Laboratory (now the Wright Laboratory), Wright-Patterson AFB, Ohio, issued proposals for a research aircraft designed to explore the forward swept wing concept. The aircraft was also intended to validate studies that said it should provide better control and lift qualities in extreme maneuvers, and possibly reduce aerodynamic drag as well as fly more efficiently at cruise speeds.
From several proposals, Grumman Aircraft Corporation was chosen in December 1981 to receive an $87 million contract to build two X-29 aircraft. They were to become the first new X-series aircraft in more than a decade. First flight of the No. 1 X-29 was Dec. 14, 1984, while the No. 2 aircraft first flew on May 23, 1989. Both first flights were from the NASA Ames-Dryden Flight Research Facility soon to be renamed the Dryden Flight Research Center.
Flight-Control System
The flight control surfaces on the X-29 were the forward-mounted canards, which shared the lifting load with the wings and provided primary pitch control; the wing flaperons (combination flaps and ailerons), used to change wing camber and function as ailerons for roll control when used asymmetrically; and the strake flaps on each side of the rudder that augmented the canards with pitch control. The control surfaces were linked electronically to a triple-redundant digital fly-by-wire flight control system (with analog back up) that provided an artificial stability.
The particular forward swept wing, close-coupled canard design used on the X-29 was unstable. The X-29's flight control system compensated for this instability by sensing flight con***ions such as attitude and speed, and through computer processing, continually adjusted the control surfaces with up to 40 commands each second. This arrangement was made to reduce drag. Conventionally configured aircraft achieved stability by balancing lift loads on the wing with opposing downward loads on the tail at the cost of drag. The X-29 avoided this drag penalty through its relaxed static stability.
Each of the three digital flight control computers had an analog backup. If one of the digital computers failed, the remaining two took over. If two of the digital computers failed, the flight control system switched to the analog mode. If one of the analog computers failed, the two remaining analog computers took over. The risk of total systems failure was equivalent in the X-29 to the risk of mechanical failure in a conventional system.
X-29 - designed with relaxed static stability to achieve less drag, more maneuverability, increased fuel efficiency. Arrows in upper illustration indicate drag-producing opposing downward forces on rear stabilizers to achieve stability. X-29 canards share lifting loads, reducing drag.
Phase 1 Flights
The No. 1 aircraft demonstrated in 242 research flights that, because the air moving over the forward-swept wing flowed inward, rather than outward as it does on a rearward-swept wing, the wing tips remained unstalled at the moderate angles of attack flown by X-29 No. 1. Phase 1 flights also demonstrated that the aeroelastic tailored wing did, in fact, prevent structural divergence of the wing within the flight envelope, and that the control laws and control surface effectiveness were adequate to provide artificial stability for this otherwise extremely unstable aircraft and provided good handling qualities for the pilots.
The aircraft's supercritical airfoil also enhanced maneuvering and cruise capabilities in the transonic regime. Developed by NASA and originally tested on an F-8 at Dryden in the 1970s, supercritical airfoils flatter on the upper wing surface than conventional airfoils delayed and softened the onset of shock waves on the upper wing surface, reducing drag. The phase 1 flights also demonstrated that the aircraft could fly safely and reliably, even in tight turns.
Phase 2 Flights
The No. 2 X-29 investigated the aircraft's high angle of attack characteristics and the military utility of its forward-swept wing/canard configuration during 120 research flights. In Phase 2, flying at up to 67 degrees angle of attack (also called high alpha), the aircraft demonstrated much better control and maneuvering qualities than computational methods and simulation models had predicted. The No. 1 X-29 was limited to 21 degrees angle of attack maneuvering.
During Phase 2 flights, NASA, Air Force, and Grumman project pilots reported the X-29 aircraft had excellent control response to 45 degrees angle of attack and still had limited controllability at 67 degrees angle of attack. This controllability at high angles of attack can be attributed to the aircraft's unique forward-swept wing- canard design. The NASA/Air Force-designed high-gain flight control laws also contributed to the good flying qualities.
Flight control law concepts used in the program were developed from radio-controlled flight tests of a 22-percent X-29 drop model at NASA's Langley Research Center, Hampton, Va. The detail design was performed by engineers at Dryden and the Air Force Flight Test Center at Edwards. The X-29 achieved its high alpha controllability without leading edge flaps on the wings for ad***ional lift, and without moveable vanes on the engine's exhaust nozzle to change or "vector" the direction of thrust, such as those used on the X-31 and the F-18 High Angle-of-Attack Research Vehicle. Researchers documented the aerodynamic characteristics of the aircraft at high angles of attack during this phase using a combination of pressure measurements and flow visualization. Flight test data from the high-angle-of-attack/military-utility phase of the X-29 program satisfied the primary objective of the X-29 program to evaluate the ability of X-29 technologies to improve future fighter aircraft mission performance.
Vortex Flow Control
In 1992 the U.S. Air Force initiated a program to study the use of vortex flow control as a means of providing increased aircraft control at high angles of attack when the normal flight control systems are ineffective.
The No. 2 X-29 was modified with the installation of two high-pressure nitrogen tanks and control valves with two small nozzle jets located on the forward upper portion of the nose. The purpose of the modifications was to inject air into the vortices that flow off the nose of the aircraft at high angles of attack.
Wind tunnel tests at the Air Force's Wright Laboratory and at the Grumman Corporation showed that injection of air into the vortices would change the direction of vortex flow and create corresponding forces on the nose of the aircraft to change or control the nose heading.
From May to August 1992, 60 flights successfully demonstrated vortex flow control (VFC). VFC was more effective than expected in generating yaw (left-to-right) forces, especially at higher angles of attack where the rudder loses effectiveness. VFC was less successful in providing control when sideslip (relative wind pushing on the side of the aircraft) was present, and it did little to decrease rocking oscillation of the aircraft
Vortex flow control involves pneumatic manipulation of forebody vortices as shown in the diagram. Exhausting air through the nozzles at the top of the airplane's forebody results in alteration or movement of the forebody vortices. As the diagram shows, air exhaused through the right nozzle accelerates the flow of the right vortex and pulls it closer to the forebody. As this occurs, the left vortex is pushed further away from the body. This results in lower pressure on the side of the blowing right nozzle, resulting in a right yawing movement of the aircraft as shown.
Summary
Overall, VFC, like the forward-swept wings, showed promise for the future of aircraft design. The X-29 did not demonstrate the overall reduction in aerodynamic drag that earlier studies had suggested, but this discovery should not be interpreted to mean that a more optimized design with forward-swept wings could not yield a reduction in drag. Overall, the X-29 program demonstrated several new technologies as well as new uses of proven technologies. These included: aeroelastic tailoring to control structural divergence; use of a relatively large, close-coupled canard for longitudinal control; control of an aircraft with extreme instability while still providing good handling qualities; use of three-surface longitudinal control; use of a double-hinged trailing-edge flaperon at supersonic speeds; control effectiveness at high angle of attack; vortex control; and military utility of the overall design.
The Aircraft
The X-29 is a single-engine aircraft 48.1 feet long. Its forward-swept wing has a span of 27.2 feet. Each X-29 was powered by a General Electric F404-GE-400 engine producing 16,000 pounds of thrust. Empty weight was 13,600 pounds, while takeoff weight was 17,600 pounds.
The aircraft had a maximum operating altitude of 50,000 feet, a maximum speed of Mach 1.6, and a flight endurance time of approximately one hour. The only significant difference between the two aircraft was an emergency spin chute deployment system mounted at the base of the rudder on aircraft No. 2. External wing structure is primarily composite materials incorporated into precise patterns to develop strength and avoid structural divergence. The wing substructure and the basic airframe itself is aluminum and titanium. Wing trailing edge actuators controlling camber are mounted externally in streamlined fairings because of the thinness of the supercritical airfoil.
Program Management
The X-29 program was funded initially by the Department of Defense Advanced Research Projects Agency. The program was managed by the Air Force's Wright Laboratory, Aeronautical Systems Division, Air Force Systems Command, Wright-Patterson AFB, Ohio.
The flight research program was conducted by the Dryden Flight Research Center, and included the Air Force Flight Test Center and the Grumman Corporation as participating organizations.
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X-30 National Aerospace Plane (NASP)
There is also the possiblity that the SR-71 follow-on was hidden in plain sight. The program to develop what is called the National Aerospace Plane (NASP), designated the X-30, had its roots in a highly classified, Special Access Required, Defense Advanced Research Projects Agency (DARPA) project called Copper Canyon, which ran from 1982 to 1985. Originally conceived as a feasibility study for a single-stage-to-orbit (SSTO) airplane which could take off and land horizontally, Copper Canyon became the starting point for what Ronald Reagan called:<1>
"...a new Orient Express that could, by the end of the next decade, take off from Dulles Airport and accelerate up to twenty-five times the speed of sound, attaining low earth orbit or flying to Tokyo within two hours..."
The next stage of the program, called Phase 2, with Copper Canyon being Phase 1, was intended to develop the technologies for a vehicle that could go into orbit as well as travel over intercontinental ranges at hypersonic speeds. There were no commitments to undertake Phase 3, the actual design, construction and flight testing of the aircraft. The decision to undertake Phase 3 based on the maturity of the requisite technologies, originally planned for 1990, was currently been postponed until at least April of 1993.<3>
There were six identifiable technologies which are considered critical to the success of the project.<3&g; Three of these "enabling" technologies are related to the propulsion system, which would consist of an air-breathing supersonic combustion ramjet, or scramjet. A scramjet is designed to compress onrushing hypersonic air in a combustion chamber. Liquid hydrogen is then injected into the chamber, where it is ignited by the hot compressed air. The exhaust, consisting primarily of water vapor, is expelled through a nozzle to create thrust. The efficient functioning of the engine is dependent on the aerodynamics of the airframe, the underside of which must function as the air inlet mechanism and the exhaust nozzle. Design integration of the airframe and engine are thus absolutely critical to project success. The efficient use of hydrogen as a fuel for such a system is another crucial element in the development of the X-30.
Other enabling technologies include the development of advanced materials including various composites and titanium-based alloys which maintain structural integrity at very high temperatures. The enormous heat loads associated with hypersonic flight, sometimes in excess of 1,800 degrees fahrenheit, will necessitate the development of active cooling systems and advanced heat-resistant materialsAlthough the NASP effort was announced by President Reagan in his State of the Union address, much of the project remains shrouded in secrecy. Indeed, the paucity of publicly available information on this project is remarkable, given the scope of the effort to date. This very high level of classification derives at least in part from the core technological innovation that was the genesis of the X-30 project.Prior analyses of scramjet propulsion systems had concluded that they would only be able to achieve speeds of about Mach 8. At this speed, the thrust emerging from the rear of the plane would be balanced by the heat generated by atmospheric drag and the high temperature of the air as it entered the front of the engine. Thus limited to a maximum speed that was only one-third the orbital velocity of Mach 25, a scramjet-propelled vehicle would need rocket motors to achieve the remaining speed needed to reach orbit. Analyses concluded that such a vehicle would be heavier and more complicated that a conventional rocket.
However, the Copper Canyon project discovered that higher speeds could be achieved through the imaginative use of active thermal management. By circulating, and thus heating, the scramjet's hydrogen propellant through the skin of the vehicle prior to injection into the engine, energy generated through atmospheric drag was added to the thrust of the scramjet, enabling it to accelerate beyond the Mach 8 thermal barrier. Initially, there was optimism that this active thermal management approach would permit speeds of up to Mach 25 using air- breathing engines alone, eliminating the need for rocket propellants to achieve orbit.
The mass saved by eliminating the final rocket propellants had to be balanced, however, against the mass of the active thermal management system. This system became more complex and massive at higher speeds. At some point, the ad***ional mass of the thermal management system needed to continue the acceleration of the air breathing scramjet would become greater than the mass of the rocket motors and propellant needed to continue the ascent to orbit.
As the NASP effort began, analysis suggested that this transition speed, at which rocket propulsion would be more efficient than continued scramjet operations, would be quite high, above Mach 20. Although this fell short of the initial promise of Copper Canyon, it nonetheless suggested that a scramjet vehicle might offer superior performance compared to conventional rockets. Over time, however, as the complexity of the active thermal management system was better appreciated, estimates of the transition speed declined to below Mach 17.<6> This diminished performance significantly reduces the attractiveness of scramjet propulsion compared with all-rocket vehicles.
Though the protection of this technological principle may explain part of the secrecy surrounding the NASP program, studies of the missions that such a vehicle might perform remain even more closely held.
Defining the mission of NASP to attract maximum support and funding has been a tricky business for program proponents. Original cost projections of $3.1 billion dollars have more than tripled, now at approximately $10 Billion total cost for the development of a pair of single-stage-to-orbit vehicles.<7>
A decision to undertake Phase 3 flight testing would have brought total program costs up to as much as $17 billion<8&t;. The target date for the first test flight of the X-30 was pushed back to the 2000-2001 period<9>, 11 years behind schedule and 500% over budget. Many years and a further $10 to $20 billion would have been required for the development of an operational vehicle. Funding this significant increase in a time of general budget cutting is not easy, and program cost overruns and delays in scheduling have made the project less attractive to many supporters.
Though the X-30 was originally touted by the Reagan administration for its civilian commercial applications and as a possible follow-on to the Space Shuttle for NASA<10>, the funding structure of the program tells another story. The Department of Defense was scheduled to fund approximately 80% of the project, or $2.65 out of $3.33 billion over the 8 years of the original project.<11> Budget allocations come primarily from the Air Force, which has seen NASP as potentially having a range of military missions.
The mystery remains of what military mission would justify this level of effort. Or perhaps there is no mystery at all. The X-30 may have been the purloined letter of military aircraft, an SR-71 follow-on hidden in plain sight. This would certainly jibe with the statement of Senator John Glenn, noted earlier and repeated here,<12>
"...what you are talking about on that system, I know what you are talking about. That is many years down the road and is still a very speculative system..."
Such a possibility would also explain the tenacious position of Congressman Dave McCurdy, the only member of Congress at the time to sit on both the Armed Services Committee and the Space and Technology Committee. From 1989 through 1992, McCurdy fought hard for continued funding for and Air Force involvement in NASP.<13>
"It's important to remember that NASP is not a NASA program. NASP is not an Air Force program. It is a national program. We believe that it is important to the country."
Presumably, an SR-71 follow-on would also be a national program of importance to the entire country. These arguments are, of course, predicated on the assumption that the NASP vehicle could fullfill such a defense mission. Concentrating on hypersonic flight in the upper stratosphere, possible military applications of a NASP derived vehicle include:<14>
space launch;
strategic bombing missions;
strategic air defense;
reconnaissance and surveillance.
While the reconnaissance and surveillance mission would be similair to the SR-71, closer examination reveals that the possible military applications provide a less than compelling rationale for the NASP effort.
As a single-stage-to-orbit vehicle with a claimed turnaround time of as little as 24 hours<15>, proponents of the Strategic Defense Initiative initially saw the X-30 leading the way to faster, cheaper access to low earth orbit, a critical aspect of lowering the cost of any space-based ballistic missile defense systems.<16> However, as it became clear that the time required for the development of an operational capability would extend far beyond the time horizon envisioned for deployment of space-based anti- missile systems, the SDI program soon lost interest in the NASP effort. A similar disenchantment has emerged within the Air Force and NASA, as the high technical risk of the project has become increasingly clear. What has also become increasingly clear is that the claims made for NASP as a space launch vehicle are eerily reminiscent of the initial claims made for the Space Shuttle in the early 1970s. The assertions that NASP will have airplane-like operating characteristics, with lower costs and fast turnaround times on the ground, are assumptions, rather than conclusions based on detailed analysis.
The potential for using NASP derived vehicles for strategic bombardment, as a hypersonic B-3, has not escaped the notice of the Air Force. Gen. Lawrence Skantze, commander of the Air Force Systems Command, observed:<17>
"We're talking about the speed of response of an ICBM and the flexibility and recallability of a bomber, packaged in a plane that can scramble, get into orbit, and change orbit so the Soviets can't get a reading accurate enough to shoot at it. It offers strategic force survivability -- a fleet could sit alert like B-52s."
The idea of reaching targets anywhere in the world in a an hour or two may be a tempting idea, but the challenge of accurately dropping a gravity bomb while travelling 20 times the speed of sound would be non-trivial. This challenge was eagerly embraced by the Energy Department, however. A Hypervelocity Aircraft- Delivered Weapon is among the five new nuclear weapons concepts currently under study by the Energy Department, as phase one or pre-phase one studies.<18>
"The need for the Hypervelocity Aircraft-Delivered Weapon derives from the ability of such a system to rapidly deliver, or threaten to deliver, nuclear weapons into a theater, while maintaining the launch platform well outside potential defenses. Hypersonic velocities enhance defense penetrability and survivability of the weapon and the delivery aircraft against state of the art defenses, while precision guidance can lead to reduced yield requirements, and consequently, collateral damage."
But a hypersonic aircraft would have high visibility to hostile defense due to its enormous heat signature and non-stealth composition of the fuselage, resembling nothing so much as a barn on fire. This is hardly a major selling point for a reconnaissance aircraft. As a bomber, a NASP derived vehicle would combine the worst features of an aircraft and a missile. With the large signature of an aircraft and the limited maneuverability of a missile warhead, it would provide a ready target for defensive systems.
A third suggested mission for NASP derived vehicles would be as a interceptor for defense of the continental United States. Robert Cooper, Director of DARPA, suggested that it could:<19>
"... fly up to maybe 150,000 to 200,000 feet, sustain mach 15 plus for a while, slow down and engage an intercontinental bomber or cruise missile carrier at ranges of 1000 nautical miles..."
But the elaborate preparations needed to maintain a liquid hydrogen fueled aircraft on alert, combined with the limited maneuverability of this type of vehicle, would limit its utility for this mission. And given the relatively low priority the United States has tra***ionally attached to strategic air defense, it is doubtful that the large investment required by NASP could be justified on these grounds.
A final application of NASP was as an intelligence collection platform. Robert Cooper suggested that it could provide:<20>
"... a globe-circling reconnaissance system, a kind of super SR-71 that would... get anywhere on the Earth within perhaps half an hour of take-off..." (emphasis added).
But such reconnaissance and surveillance activities of hypersonic craft are constrained by the high speeds and altitudes at which the X-30 or its derivatives would travel. At altitudes nearly three times that of standard reconnaissance aircraft<21> and a fuel cost 3 times that of aviation grade kerosene,<22> it would certainly seem more economical to get information of comparable (or better) resolution from a satellite in low earth orbit, which could make another pass in 90 minutes instead of being forced to return to base for refuelling.<23>
Although some proponents have viewed these military missions as potentially attractive, a Committee of the National Research Council expressed doubts about the operational effectiveness of NASP derived vehicles:<37>
"Another restriction is inherent in the base support requirements associated with cryogenic fuels. They will require a complete departure from conventional airport storage and distribution facilities. For economic reasons alone, we are unable to envision a network of airfields giving the flexibility that today's aircraft enjoy.
"... sustained cruising flight in the atmosphere roughly between Mach numbers 8 and 20 ... is a very stressful flight environment with high skin temperatures, control and maneuvering difficulties, ionized boundaries through which sensors must operate, and high infrared signatures which would make the vehicle vulnerable to detection. For these reasons, we have great reservations about the military utility of sustained hypersonic flight in the atmosphere above Mach number 8."
A draft analysis done at the RAND Corporation was even more pessimistic:<25>
"Grave doubts exist that NASP could come anywhere near its stated/advertised cost, schedule, payload fees to orbit, etc.... On the basis of current knowledge, it is hard to defend previous DoD plans for NASP on the basis of any singular mission utility sufficiently attractive to operators... NASP could do many missions (but none is singularly persuasive)... No compelling "golden mission" exists for NASP."
NASA was disinclined to significantly increase its share of program costs given its current budgetary constraints<26>, and the Air Force, which has borne the brunt of development costs of Phase 2, expressed doubts about the future viability of the program. According to Martin Faga, Assistant Secretary of the Air Force for Space:<27>
"...these are exciting ideas... but they are not ready for commitment."
Clearly, no single vehicle can serve commercial, civil space and military masters at the same time. In spite of efforts to be all things to all people, the NASP remained without a truly credible mission, and ultimately proponents were unable to save it from termination.
The Hypersonic Systems Technology Program (HySTP), initiated in late 1994, was designed to transfer the accomplishments made in hypersonic technologies by the National Aero-Space Plane (NASP) program into a technology development program.
<1> State of the Union Address, February 4, 1986.
<2> According to project manager Robert Barthelemy. Aerospace America, September 1991. page 6.
<3> United States General Accounting Office. "National Aero-Space Plane: A Technology Development and Demonstration Program to Build the X-30." USGAO/ NSIAD-88-122. April 1988. pages 35-40.
<4> GAO ibid. page 38.
<5> "DARPA Chief Notes Potential of Supersonic Combustion Ramjet," Aerospace Daily, 29 March 1985, page 165.
<6> "NASP Moves at Slower Speed," Military Space, 17 July 1989, pages 1, 7-8.
<7>United States General Accounting Office. "National Aero-Space Plane: Key Issues Facing the Program." March 31, 1992. p.
<8> GAO ibid. page 7.
<9> Defense Daily. April 17, 1992. page 103.
<10>Aerospace Daily. March 28, 1986. page 484.
<11> GAO ibid. page 19.
<12> United States Senate Armed Services Committee, 101st Congress, 1st Session, ibid.
<13> Press release. Office of Congressman Dave McCurdy. June 3, 1991.
><14> Williams, Robert M. "National Aero-Space Plane: Technology for America's Future." Aerospace America. November 1986. page 20.
<15> World Aerospace Weekly. November 11, 1988.
<16> Marshall, Eliot. "NASA and Military Press for a Spaceplane." News and Comment. January 10, 1986, pages 105-107.
<17> Williams, Robert, "National Aero-Space Plane: Technology for America's Future," Aerospace America, November 1986, pages 18-22.
<18> House of Representatives Appropriations Committee Energy and Water Development Subcommittee, Energy and Water Development Appropriations for 1993, 102nd Congress, 2nd Session, Part 6, pages 1669-1670.
<19> "DARPA Chief Notes Potential of Supersonic Combustion Ramjet," Aerospace Daily, 29 March 1985, page 165.
<20> ibid.
<21> Defense Daily. April 20, 1988. page 295.
<22> Aerospace Daily. March 14, 1992. page 408.
<23> Defense Daily. April 20, 1988. page 295.
<24> National Research Council Committee on Hypersonic Technology for Military Applications, Hypersonic Technology for Military Applications, (Washington, National Research Council, 1989), page 12.
<25> Augenstein, Bruno, Assessment of NASP: Future Options, (Santa Monica, RAND, June 1989), WD-4437-AF.
<26> "The Goldin Age" Space Business News, July 6, 1992.
<27> Inside the Air Force. March 27, 1992. page 3.
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X-31 Enhanced Fighter Maneuverability Demonstrator
The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator, flown at NASA's Dryden Flight Research Center, Edwards, Calif., provided information which is invaluable for proceeding with the designs of the next generation highly maneuverable fighters.
The X-31 program showed the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight to very high angles of attack. The result is a significant advantage over conventional fighters in a close-in-combat situation.
"Angle-of-attack" (alpha) is an engineering term to describe the angle of an aircraft's body and wings relative to its actual flight path. During maneuvers, pilots would like to fly at extreme angles of attack to facilitate rapid turning and pointing against an adversary. With older aircraft designs, entering this flight regime often led to loss of control, resulting in loss of the aircraft, pilot or both.
Three thrust vectoring paddles made of graphite epoxy and mounted on the X-31's aft fuselage are directed into the engine exhaust plume to provide control in pitch (up and down) and yaw (right and left) to improve maneuverability. The paddles can sustain temperatures of up to 1,500 degrees centigrade for extended periods of time. In ad***ion, the X-31s is configured with movable forward canards, wing control surfaces, and fixed aft strakes. The canards are small wing-like structures located just aft of the nose, set on a line parallel to the wing between the nose and the leading edge of the wing. Normally "weathervaned" with the prevailing airflow, these devices are programmed to be used for aerodynamic recovery from high angles of attack in event of thrust vectoring system failure. The strakes are set along the same line between the trailing edge of the wing and the engine exhaust. The strakes supply ad***ional nose down pitch control authority from very high angles of attack. Small fixed nose strakes are also employed to help control sideslip.
The X-31 flight demonstration program was focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. This is expected to lead to design methods providing better maneuverability in future high performance aircraft and make them safer to fly.
Phase One
Phase I was the conceptual design phase. During this phase the payoff expected from the application of EFM concepts in future air battles was outlined and the technical requirements for a demonstrator aircraft were defined.
Phase Two
Phase II carried out the preliminary design of the demonstrator and defined the manufacturing approach to be taken. Three major government design reviews were held during the phase to thoroughly examine the proposed design. Technical experts from the U.S. Navy, Federal Ministry of Defense and NASA all contributed to the careful examination of all aspects of the design.
Phase Three
Phase III initiated and completed the detailed design fabrication and assembly of two aircraft. This phase required that both aircraft fly a limited test flight program. The first aircraft rolled out on March 1, 1990, followed by a first flight at Air Force Plant 42, Palmdale, Calif., on Oct. 11, 1990. The aircraft was piloted by Rockwell chief test pilot Ken Dyson, and reached a speed of 340 mph and an altitude of 1 0,000 feet during the initial 38-minute flight.
The second aircraft made its first flight on Jan.19, 1991, with Deutsche Aerospace chief test pilot Dietrich Seeck at the controls.
Flight Summary
During the program's initial phase of flight test operations at the Rockwell Aerospace facility in Palmdale, Calif., the two aircraft were flown on 108 test missions, achieving thrust vectoring in flight and expanding the post-stall envelope to 40 degrees angle of attack. Operations were then moved to Dryden in February 1992 at the request of the Advanced Research Projects Agency (ARPA).
At Dryden, the International Test Organization (ITO) expanded the aircraft's flight envelope, including military utility evaluations that pitted the X-31 against similarly equipped aircraft to evaluate the maneuverability of the X-31 in simulated combat. The ITO, managed by the Advanced Research Projects Agency (ARPA), includes NASA, U.S. Navy, the U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, and Deutsche Aerospace (formerly Messerschmitt-Bolkow-Blohm).
The first NASA flight under the ITO took place in April 1992. By July 1992, the X-31 program was continuing the initial stage of post stall envelope expansion.
The X-31 achieved controlled flight at 70 degrees angle of attack at Dryden on Nov. 6, 1992. On the same day, a controlled roll around the aircraft's velocity vector was accomplished at 70 degrees angle of attack.
On April 29, 1993, the No. 2 X-31 successfully executed a rapid minimum radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. The revolutionary maneuver has been dubbed the "Herbst Maneuver," after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. The term "J Turn" is also used to describe this type of maneuver, when flown to an arbitrary heading change.
The first tactical maneuver with a cooperative F/A-18 as adversary was accomplished in June 1993. In August 1993, the X-31 demonstrated full capability in flying Basic Fighter Maneuvers.
In October 1993 the program logged its 300th flight. The final tactical evaluation phase, consisting of Close-In-Combat (CIC) tests with unchoreographed flights against the F/A-18 adversary, began in November 1993.
During November and December 1993 the X-31 also reached supersonic speed (Mach 1.28).
A total of 160 flights were completed by the X-31 program in 1993 setting a new annual experimental aircraft record. One of the two X-31s flew 103 of those flights. The program also set a new monthly record of 21 research flights in August 1993.
The evaluation of the X-31's unique capabilities in close combat (CIC) was completed on March 1, 1994.
Evaluation of the X-31 as a fighter maneuverability demonstrator by the ITO is expected to conclude in early 1995.
The No. 1 X-31 ship was lost in an accident Jan. 19, 1995. The pilot, Karl Lang, ejected safely at 18,000 feet before the aircraft crashed into an unpopulated region of the desert just north of Edwards Air Force Base. There was no private property damage.
Quasi-Tailless Demonstration
In 1994, software was installed in the X-31 to demonstrate the feasibility of stabilizing a tailless aircraft at supersonic speed, using thrust vectoring. This software allows destabilization through the control laws of the aircraft in incremental steps to the goal of simulation 100 percent tail-off. Quasi-tailless tests began in 1994. The first phase started with supersonic evaluations at Mach 1.2. Later subsonic evaluations were performed. During the flights the aircraft was destabilized with the rudder to stability levels that would be encountered if the aircraft had a reduced size vertical tail.
The quasi-tailless testing is providing data to industry on the benefits of drag reduction, radar cross section, and weight reduction that could be used for future commercial and military designs and modifications.
Helmet Mounted Visual/Audio Display
Installation of a Helmet Mounted Visual/Audio Display (HMVAD) was completed on the X-31 (aircraft No. 2) in October 1993. The purpose of the HMVAD is to provide out-of-the-****pit situation awareness and a simulated helmet-mounted sight to the pilot during high angle of attack combat maneuvering.
The system consists of a GEC Viper helmet with symbology projected on its visor by a monocular CRT. Also included is a Polhemus head tracker and an angle-of-attack audio cueing device. Both of these features have been demonstrated on the X-31, during post-stall close-in-combat, a first for any aircraft. This equipment will be the baseline for a follow-on virtual adversary program to demonstrate the feasibility of combat training against onboard and uplinked targets displayed by the helmet.
An international test organization, managed by the Advanced Research Projects Agency (ARPA), is conducting the flight tests. In ad***ion to ARPA and NASA, the International Test Organization (ITO) includes the U.S. Navy, the U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany and Deutsche Aerospace. About 110 people from the ITO agencies are assigned to the program. NASA is responsible for flight test operations, and aircraft maintenance. Research engineering is an ITO team effort.
The X-31 is the first international experimental aircraft development program administered by a U.S. government agency. It is one, if not the most, successful effort initiated by the NATO Cooperative Research and Development Program.
The X-31 program logged an X-Plane record total of 524 flights in 52 months with 14 pilots from NASA, U.S. Navy, U.S. Marine Corps, U.S. Air Force, German Air Force, DASA, Rockwell International, and Deutsche Aerospace, flying the aircraft.
Specifications

Designed and constructed as a demonstrator aircraft by Rockwell Aerospace, North American Aircraft and Deutsche Aerospace.
The X-31 is a single seat aircraft with a wing span of 23.83 feet (7.3 m).
The fuselage length is 43.33 feet (1 2.8 m).
The X-31 is powered by a single General Electric P404-GE-400 turbofan engine, producing 16,000 pounds (71,168 N) of thrust in afterburner.
Typical takeoff weight of the X-31 is 16,100 pounds (7,303 kg).
The X-31's normal flight envelope includes speeds up to Mach 0.9 with an altitude capability of 40,000 feet (12,192 m). For specific tests to determine thrust vector effectiveness at supersonic speeds the aircraft was flown to Mach 1.28 at 35,000 feet.

X32 Ảnh để sau các bác nhé.
Joint Strike Fighter (JSF)
The Joint Strike Fighter (JSF) is a multi-role fighter optimized for the air-to-ground role, designed to affordably meet the needs of the Air Force, Navy, Marine Corps and allies, with improved survivability, precision engagement capability, the mobility necessary for future joint operations and the reduced life cycle costs associated with tomorrow?Ts fiscal environment. JSF will benefit from many of the same technologies developed for F-22 and will capitalize on commonality and modularity to maximize affordability.
The 1993 Bottom-Up Review (BUR) determined that a separate tactical aviation modernization program by each Service was not affordable and canceled the Multi-Role Fighter (MRF) and Advanced Strike Aircraft (A/F-X) program. Acknowledging the need for the capability these canceled programs were to provide, the BUR initiated the Joint Advanced Strike Technology (JAST) effort to create the building blocks for affordable development of the next-generation strike weapons system. After a review of the program in August 1995, DoD dropped the "T" in the JAST program and the JSF program has emerged from the JAST effort. Fiscal Year 1995 legislation merged the Defense Advanced Research Projects Agency (DARPA) Advanced Short Take-off and Vertical Landing (ASTOVL) program with the JSF Program. This action drew the United Kingdom (UK) Royal Navy into the program, extending a collaboration begun under the DARPA ASTOVL program.
The JSF program will demonstrate two competing weapon system concepts for a tri-service family of aircraft to affordably meet these service needs:
USAF-Multi-role aircraft (primarily air-to-ground) to replace F-16 and A-10 and to complement F-22. The Air Force JSF variant poses the smallest relative engineering challenge. The aircraft has no hover criteria to satisfy, and the characteristics and handling qualities associated with carrier operations do not come into play. As the biggest customer for the JSF, the service will not accept a multirole F-16 fighter replacement that doesn't significantly improve on the original.
USN-Multi-role, stealthy strike fighter to complement F/A-18E/F. Carrier operations account for most of the differences between the Navy version and the other JSF variants. The aircraft has larger wing and tail control surfaces to better manage low-speed approaches. The internal structure of the Navy variant is strengthened up to handle the loads associated with catapult launches and arrested landings. The aircraft has a carrier-suitable tailhook. Its landing gear has a longer stroke and higher load capacity. The aircraft has almost twice the range of an F-18C on internal fuel. The design is also optimized for survivability.
USMC-Multi-role Short Take-Off & Vertical Landing (STOVL) strike fighter to replace AV-8B and F/A-18A/C/D. The Marine variant distinguishes itself from the other variants with its short takeoff/vertical landing capability.
UK-STOVL (supersonic) aircraft to replace the Sea Harrier. Britain's Royal Navy JSF will be very similar to the U.S. Marine variant.
The JSF concept is building these three highly common variants on the same production line using flexible manufacturing technology. Cost benefits result from using a flexible manufacturing approach and common subsystems to gain economies of scale. Cost commonality is projected in the range of 70-90 percent; parts commonality will be lower, but emphasis is on commonality in the higher-priced parts.
The Lockheed Martin X-35 concept for the Marine and Royal Navy variant of the aircraft uses a shaft-driven lift-fan system to achieve Short-Takeoff/Vertical Landing (STOVL) capability. The aircraft will be configured with a Rolls-Royce/Allison shaft-driven lift-fan, roll ducts and a three-bearing swivel main engine nozzle, all coupled to a modified Pratt & Whitney F119 engine that powers all three variants.
The Boeing X-32 JSF short takeoff and vertical landing (STOVL) variant for the U.S. Marine Corps and U.K. Royal Navy employs a direct lift system for short takeoffs and vertical landings with uncompromised up-and-away performance.
Key design goals of the JSF system include:
Survivability: radio frequency/infrared signature reduction and on-board countermeasures *****rvive in the future battlefield--leveraging off F-22 air superiority mission support
Lethality: integration of on- and off-board sensors to enhance delivery of current and future precision weapons
Supportability: reduced logistics footprint and increased sortie generation rate to provide more combat power earlier in theater
Affordability: focus on reducing cost of developing, procuring and owning JSF to provide adequate force structure
JSF?Ts integrated avionics and stealth are intended to allow it to penetrate surface-to-air missile defenses to destroy targets, when enabled by the F-22?Ts air dominance. The JSF is designed to complement a force structure that includes other stealthy and non-stealthy fighters, bombers, and reconnaissance / surveillance assets.
JSF requirements definition efforts are based on the principles of Cost as an Independent Variable: Early interaction between the warfighter and developer ensures cost / performance trades are made early, when they can most influence weapon system cost. The Joint Requirements Oversight Council has endorsed this approach.
The JSF?Ts approved acquisition strategy provides for the introduction of an alternate engine during Lot 5 of the production phase, the first high rate production lot. OSD is considering several alternative implementation plans which would accelerate this baseline effort.
Program Status
The focus of the program is producing effectiveness at an affordable price?"the Air Force?Ts unit flyaway cost objective is $28 million (FY94$). This unit recurring flyaway cost is down from a projected, business as usual,cost of $36 million. The Concept Demonstration Phase (CDP) was initiated in November 1996 with the selection of Boeing and Lockheed Martin. Both contractors are: (1) designing and building their concept demonstration aircraft, (2) performing unique ground demonstrations, (3) developing their weapon systems concepts. First operational aircraft delivery is planned for FY08.
The JSF is a joint program with shared acquisition executive responsibilities. The Air Force and Navy each provide approximately equal shares of annual funding, while the United Kingdom is a collaborative partner, contributing $200 million to the CDP. CDP, also known as the Program Definition and Risk Reduction (PDRR) phase, consists of three parallel efforts leading to Milestone II and an Engineering and Manufacturing Development (EMD) start in FY01:
Concept Demonstration Program. The two CDP contracts were competitively awarded to Boeing and Lockheed Martin for ground and flight demonstrations at a cost of $2.2 billion for the 51-month effort, including an ad***ional contract to Pratt & Whitney for the engine. Each CDP contractor will build concept demonstrator aircraft (designated X-32/35). Each contractor will demonstrate commonality and modularity, short take-off and vertical landing, hover and transition, and low-speed carrier approach handling qualities of their aircraft.
Technology Maturation. These efforts evolve key technologies to lower risk for EMD entry. Parallel technology maturation demonstrations are also an integral part of the CDP / PDRR objective of meeting warfighting needs at an affordable cost. Focus is on seven critical areas: avionics, flight systems, manufacturing and producibility, propulsion, structures and materials, supportability, and weapons. Demonstration plans are coordinated with the prime weapon system contractors and results are made available to all program industry participants.
Requirements Definition. This effort leads to Joint Operational Requirements Document completion in FY00; cost/performance trades are key to the process.
LockMart JSF Design - X-35


Boeing JSF Design - X-35


Specifications
Function strike fighter
Contractor two competing teams:
Lockheed-Martin
Boeing
Service U.S. Air Force U.S. Marine Corps
U.K. Royal Navy U.S. Navy
Variants Conventional Takeoff and Landing (CTOL) Short Takeoff and Vertical Landing (STOVL) Carrier-based (CV)
Unit Cost FY94$ $28M $35M $38M
Propulsion Baseline: Pratt & Whitney F119-PW-100 derivative from F-22 Raptor
Alternate Engine: General Electric F120 core
Thrust
Empty Weight ~22,500 lbs ~24,000 lbs
Internal Fuel 15,000 lbs 16,000 lbs
Payload 13,000 lbs 17,000 lbs
Maximum Takeoff Weight ~50,000 lbs
Length 45 feet
Wingspan 36 feet 30 feet
Height
Ceiling
Speed supersonic
Combat Radius over 600 nautical miles
Crew one
Armament
First flight 1999
Date Deployed 2008
Inventory Objectives U.S. Air Force
2,036 aircraft U.S. Marine Corps
642 aircraft
U.K. Royal Navy
60 aircraft U.S. Navy
300 aircraft
Sources and Resources
Dave Hasting's JSF Page
Joint Adv Strike Tech Program FY98 R&D Budget Request
0603800N JOINT ADVANCED STRIKE JASTP FY98 R&D Budget Request
The Joint Strike Fighter Derek W. Avance; Christopher S. Ceplecha; Robert E. Clay; Terry M. Featherston; David S. Grantham; Thomas E. Gregory (Faculty Advisor); Patrick A. Kelleher; David Kelly; Thomas L. Moore (Faculty Advisor); Garry L. Pendleton; John Rupp; Christopher E. Yelder Air Command and Staff College 1996
JSF excerpts from House National Security Committee Report on House National Defense Authorization Act for FY 1998
MEMORANDUM FOR CORRESPONDENTS June 23, 1998 The Joint Strike Fighter program office today announced today that Pratt & Whitney began ground testing the second of two developmental engine designs for the Joint Strike Fighter (JSF) Concept Demonstrator Aircraft (CDA).
Designing The Next Generation Strike Fighter Brigadier General Leslie Kenne, Director, Joint Strike Fighter Program Office [1500k PDF]
Boeing Refines Joint Strike Fighter Design February 4, 1999 - Boeing has taken the next step in maturing the design for its Joint Strike Fighter (JSF), improving its affordability, supportability and performance capabilities while maintaining the fundamentals of its original weapon-system concept.
Joint Strike Fighter concept demonstrators slated to begin flying Air Force Print News 24 May 2000 -- Competitors for the Air Force's newest multi-role aircraft, the Joint Strike Fighter, will begin flying their concept demonstrators in the next few months.
Joint Strike Fighter Acquisition Strategy, Boeing Press Release, 22 June 2000 -- Boeing supports today's Defense Department announcement confirming the current winner-take-all strategy on the Joint Strike Fighter competition.
Cohen: Joint Strike Fighter program must stay on schedule, Stars and Stripes, 24 June 2000 -- Defense Secretary William Cohen sent a letter to senior House and Senate lawmakers Thursday urging them to keep the funding and schedule for the Pentagon's Joint Strike Fighter aircraft on schedule.
First Joint Strike Fighter lands at Edwards, Air Force Print News, 20 September 2000 -- One version of the Joint Strike Fighter program made its first flight early Sept. 18.
NAVAIR test pilot breaks new ground in JSF testing, NAWCAD Public Affairs, 26 October 2000 -- In what could be the one of the last "first flights" of a new fighter program for a long time, Boeing chief test pilot Fred Knox piloted the X-32 Joint Strike Fighter concept demonstrator on its first flight thrilling none more than Navy Cmdr. Phil "Rowdy" Yates.
The Lockheed Martin Joint Strike Fighter X-35A successfully executed a series of airborne refuelings during its 10th flight, demonstrating the aircraft's flying qualities during refueling and paving the way for extended test flights., Air Force Print News, 15 November 2000 -- The Lockheed Martin Joint Strike Fighter X-35A successfully executed a series of airborne refuelings during its 10th flight, demonstrating the aircraft's flying qualities during refueling and paving the way for extended test flights.
Boeing X-32A begins simulated carrier-landing tests, Air Force Print News, 17 November 2000 -- The Boeing Joint Strike Fighter X-32A concept demonstrator aircraft began field carrier-landing practice tests Nov. 15 to demonstrate flying and handling qualities during low-speed aircraft carrier approach.
X-35A breaks sound barrier, Air Force Print News, 27 November 2000 -- With its flight testing now complete, the X-35A returned to Lockheed Martin's nearby Palmdale, Calif., facility to be fitted with a shaft-driven lift-fan propulsion system. It will be renamed the X-35B and will begin ground testing in preparation for its short takeoff/vertical landing demonstrations.
Navy Variant of Lockheed Martin JSF Takes Flight, Lockheed Martin Press Release, 16 December 2000 -- The United States Navy version of the Lockheed Martin Joint Strike Fighter (JSF) demonstrator took to the skies on Saturday, Dec. 16, initiating a flight-test program that will focus on carrier-suitable flying qualities and aircraft performance.
Boeing Completes JSF X-32B Engine Accelerated Mission Tests, Boeing Press Release, 15 January 2001 -- Boeing, Pratt & Whitney and Rolls-Royce today completed accelerated mission tests of the Joint Strike Fighter X-32B qualification engine at Pratt & Whitney's facility in West Palm Beach, Fla.
U.S., U.K. Sign Joint Strike Fighter Agreement Jan. 17, U.S. Department of Defense, 17 January 2001 -- Deputy Defense Secretary Rudy de Leon signed a U.S.-United Kingdom Memorandum of Understanding on the joint strike fighter (JSF) with Baroness Symons of Vernham Dean, U.K. Minister of State for Defence Procurement, in a ceremony at the Pentagon January 17.
U.S., UK Defense Officials on Joint Strike Fighter Jet, U.S. Department of Defense, 17 January 2001 -- The United States and the United Kingdom signed an agreement on the Joint Strike Fighter military aircraft (JSF) at a ceremony January 17 at the Pentagon.
Boeing Completes JSF X-32B Maximum-Thrust STOVL Engine Runs, Boeing Press Release, 08 March 2001 -- Boeing yesterday completed maximum-thrust engine runs in the short-takeoff-and-vertical-landing (STOVL) mode on its Joint Strike Fighter X-32B concept demonstrator, achieving a major milestone in preparation for first flight.
Boeing JSF X-32B Completes Successful First Flight, Boeing Press Release, 29 March 2001 -- The Boeing Joint Strike Fighter X-32B demonstrator today successfully completed its first flight, entering a four-month test program to validate the Boeing direct-lift approach to short-takeoff-and-vertical-landing (STOVL) flight.
Joint Strike Fighter Agreement Signed , DOD News Release, 06 June 2001 -- Officials from Pratt & Whitney (P&W) and GE Aircraft Engines (GEAE) today signed an agreement to work together on the Joint Strike Fighter (JSF) program, to assure that both companies' engines will be physically and functionally interchangeable across all three variants of the JSF aircraft.
Joint Strike Fighter Homepage - Air Force
Lockheed Martin JSF Homepage
Boeing JSF Homepage
DOD News Briefing -- Joint Strike Fighter Development Selection - Nov. 16, 1996
Joint Strike Fighter Armed Forces Journal International, February 1996
Politics could cloud fighter plane's future Fort Worth Star-Telegram (Jun 24, 1996)

X-33 VentureStar
The Reusable Launch Vehicle (RLV) Technology Program is a partnership between NASA and industry to design a new generation of launch vehicles expected to dramatically lower the costs of putting payloads in space. Today's launch systems are complex and costly to operate. The RLV program stresses a simple, fully reusable vehicle that will operate much like an airliner. NASA hopes to cut payload costs from $10,000 a pound, as it is today, to about $1,000 a pound. To accomplish this goal, NASA sought proposals from US aerospace industries for the RLV Technology Program.
On August 5, 1994, President Clinton issued the National Space Transportation Policy and designated NASA as the Lead Agency for advanced technology development and demonstration of the next generation of RLVs. Three concepts and preliminary designs were prepared independently by: (1) Lockheed Martin Skunk Works, Palmdale, California; (2) McDonnell-Douglas Aerospace, Huntington Beach, California; and (3) Rockwell International Corporation, Space Systems Division, Downey, California.
>In July 1996, NASA selected Lockheed Martin Skunk Works of Palmdale CA to design, build and test the X-33 experimental vehicle for the RLV program. The selected team consists of Lockheed-Martin (lead by the Skunk Works in Palmdale, CA), Rocketdyne (Engines), Rohr (Thermal Protection Systems), Allied Signal (Subsystems), and Sverdrup (Ground Support Equipment), and various NASA and DoD laboratories. NASA has budgeted $941 million for the X-33 program through 1999. Lockheed Martin will invest at least $212 million in its X-33 design.
Specific technology objectives of the X-33 space vehicle include:
demonstrate a reusable cryogenic tank system, including the tanks for liquid hydrogen (LH2) and liquid oxygen (LOX), cryogenic insulation, and an integrated thermal protection system (TPS)
verify TPS durability, low maintenance, and performance at both low and high temperatures
demonstrate guidance, navigation, and control systems, including autonomous flight control of checkout, takeoff, ascent, flight, reentry, and landing for an autonomously controlled space vehicle
achieve hypersonic flight speeds (speeds up to Mach 15 or 18,000 km/hr(11,000 mph))
demonstrate composite primary space vehicle structures integrated with the TPS
demonstrate ability to perform 7-day turnarounds between three consecutive flights (a turnaround is the amount of time required from a takeoff and flight until the vehicle is serviced, refueled, and ready to fly again)
demonstrate ability to perform a 2-day turnaround between two consecutive flights
demonstrate that a maximum of 50 personnel performing hands-on vehicle operations, maintenance, and refueling can successfully accomplish flight readiness for two flights.
Specific test flight objectives would include demonstration of:
successful interaction of the engines, airframe, and launch (also referred to as takeoff) facility
engine performance, thrust, and throttling capability meets specifications
operability and control of the X-33's flight control surfaces (canted fins, flaps, ailerons, etc.)
durability of the metallic thermal protection system during repeated flights
performance of the guidance, navigation, and control system
performance of primary operations facilities, including takeoff infrastructure
automated landing at a designated point on the runway
verification of tasks required to service the vehicle on landing and prepare it for next flight in minimal time.
The reusable, wedge-shaped X-33, called VentureStar, will be about half the size of a full-scale RLV. The X-33 will not take payloads into space; it will be used only to demonstrate the vehicle's design and simulate flight characteristics of the full-scale RLV. Lockheed Martin plans to conduct the first flight test in March 1999 and achieve at least 15 flights by December 1999. NASA has budgeted $941 million for the project through 1999. Lockheed Martin will invest $220 million in its X-33 design. After the test program, government and industry will decide whether or not to continue with a full-scale RLV.
The RLV will fly much like the Space Shuttle. It will take off vertically and land on a runway. However, there are differences between the two vehicles. The RLV will be a means of transport only. It will not be used as a science platform like the current Space Shuttle.
Also, the RLV will be a single-stage-to-orbit spacecraft it does not drop off components on its way to orbit. It will rely totally on its own built-in engines to reach orbit, omitting the need for ad***ional boosters. Unlike the shuttle, the RLV will use a new linear aerospike engine, which looks and runs much differently than the bell-shaped Space Shuttle Main Engine. NASA considered the aerospike engine for the Space Shuttle 25 years ago, but opted to use the Space Shuttle Main Engine, also built by Rocketdyne. The aerospike has been revived and enhanced to power the RLV. The aerospike nozzle is shaped like an inverted bell nozzle. Where a bell nozzle begins small and widens toward the opening of the nozzle like a cone, the aerospike decreases in width toward the opening of the nozzle. The aerospike is 75 percent shorter than an equivalent bell nozzle engine. It is also lighter, and its form blends well with the RLV's lifting body airframe for lower drag during flight. The shape spreads thrust loads evenly at the base of the vehicle, causing less structural weight.
The half-scale X-33 test vehicle will use two smaller test versions of the aerospike, whilet the full-scale RLV will use seven aerospike engines. The X-33 main propulsion system (full system of engines and propellant tanks) consists of two J-2S aerospike engines, one aluminum LOX tank in the front, and two LH2 tanks in the rear for short- and mid-range flights. The vehicle could sustain one engine out at liftoff and still have sufficient power from the remaining engine to continue acceleration and make a safe landing at the intended runway or an abort landing area depending on where the engine out occurred during flight. For the long- range flights an engine out situation could be tolerated approximately 30 seconds after liftoff.
The X-33 was scheduled to complete its first flight by March of 1999. As of early 1999 the projected date for the X-33 rollout was May 1999, with its first flight planned for that July. The program is scheduled to be completed by the year 2000. The baseline test program would include a combined total of approximately 15 flights beginning in July 1999 and concluding in December 1999. The baseline test flight plan includes three short-range, seven mid-range, and five long-range test flights. Actual numbers of test flights to any range may vary due to changing plans and/or actual test flight data evaluation.
Test flights involve: (1) launching the X-33 from a vertical position like a conventional space launch vehiclê?"this reduces the weight of the landing gear and wheels to only that required *****pport an unfueled vehicle (baseline dry weight of vehicle is approximately 29,500 kg (65,000 lb) and fueled weight of X-33 is approximately 123,800 kg (273,000 lb)); (2) accelerating the vehicle to top speeds of Mach 15 (15 times the speed of sound or approximately 18,000 km/hr (11,000 mph) and reaching high altitudes up to approximately 75,800 m (250,000 ft); (3) shutting down the engines; gliding over long distances up to 1,530 km (950 mi) downrange of the launch site followed by conducting terminal area energy maneuvers to reduce speed and altitude; and (4) landing like a conventional airplane.
Optimally, the flight test plan to meet Program objectives would involve flights of approximately 160, 720, or 1,530 km (100, 450, and 950 mi). Landing sites meeting the above criteria and providing 3,050 m (10,000 ft) of hard surface are referred to as short-, mid-, and long-range landing sites, respectively. The X-33 Program prefers to land the vehicle on a dry lake bed at least for its first flight in order to have a wider and slightly safer landing area than conventional runways offer. The same philosophy was used for the Orbiter's and most X-planes' first landings.
The launch site is located within Edwards Air Force Base, California. A total of fifteen launches are scheduled over a period of approximately one year. The X-33 will blast off from the site near Haystack Butte, located at the eastern edge of the Base near the AFRL/PR. Predominantly local NASA and USAF tracking and command assets will be utilized *****pport this phase of flight. Construction of the X-33 launch site at was completed in December 1998, just a little more than 12 months after groundbreaking.
Once the X-33 is readied for flight, the engines will be fired two times on the launch pad, with the second firing having a duration of 20 seconds. The longest flight will be approximately 20 minutes at an altitude of about 55 miles. The plan is to demonstrate a 2-day turnaround for the vehicle. Landing sites include Silurian Dry Lake Bed, Michael Army Air Field and Malmstrom Air Force Base. One of NASA's 747s will be used to carry the X-33 from its landing destinations back to Edwards.
Silurian Dry Lake Bed near Baker, California is approximately 3000 feet wide and 12000 feet long. The lake bed will be the site of the first landing attempts for the X-33 vehicle. Three flights are scheduled to Silurian Lake that will include vehicle speeds in excess of Mach 3. The flights are scheduled to start in mid 1999.
Michael Army Airfield will be the second landing site for the X-33. This will also be the first downrange runway landing. Michael Army Airfield is part of the Utah Test and Training Range, located south of Salt Lake City. This airfield is located on the eastern boundary of Dugway. The airfield has a 3,960 m (13,000 ft) long by 61 m (200 ft) wide hard surfaced runway. Immediate surrounding terrain is relatively flat. It is a secure facility with a long history of flight operations. The airspace above Dugway Proving Ground is restricted military airspace controlled by Hill Air Force Base which manages and approves use of the Utah Test and Training Range (UTTR). Seven flights are scheduled to Michael with vehicle speeds in excess of Mach 10. Flights are scheduled to start in the latter part of 1999.
Malmstrom Air Force Base will be the third and final landing site for the X-33. The airfield was closed on Decmeber 31, 1996, except for the area used by helicopters of the Malmstrom's Air Rescue Flight. The airfield has a hard surface runway approximately 3,500 m (11,500 ft) long and 61 m (200 ft) wide with a 305 m (1,000 ft) overrun at each end. Since closure of the airfield, the USAF has no plans or budget to operate the runway. Five flights are scheduled to the Malmstrom runway with vehicle speeds in excess of Mach 15. Flights are scheduled to start in the spring of 2000.

X-33 @ NASA
http://rlv.msfc.nasa.gov/stpweb/x33/index.html
X-33 History Project Home Page
http://www.hq.nasa.gov/office/pao/History/x-33/menu1.htm
VentureStar home page @ LockMart
http://www.venturestar.com/
X-33 Advanced Technology Demonstrator Vehicle Program Final Environmental Impact Statement
http://eemo.msfc.nasa.gov/eemo/x33_eis/
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X-34
On August 28, 1996, NASA awarded to Orbital Sciences Corporation (OSC) a contract for the design, development, and testing of the X-34 technology testbed demonstrator vehicle. First flight was scheduled before the end of 1998. The intent of the X-34 program is to demonstrate "key technologies" integratable to the Reusable Launch Vehicle program. This vehicle was conceived as a bridge between the Clipper Graham (DC-XA) and the X-33. The contract is managed by the Marshall Space Flight Center. (MSFC)
The objective of the X-34 program is flight demonstration of key reusable launch vehicle operations and technologies directed at the reusable launch vehicle goals of low-cost space access and commercial space launch competitiveness. The vehicle is being designed and developed by Orbital Sciences Corporation. It will be powered by a government-furnished engine. The main engine is a 60,000 pound thrust version of the Fastrac LOX/kerosene engine being developed by the Marshall Space Flight Center. This is a simple engine which uses a gas generator cycle, and a single turbopump based on the previously developed Marshall Simplex LOX pump.
The X-34 is considerably smaller and lighter than the X-33. It is capable of hypersonice flight to Mach 8, compared with the X-33's Mach 15. Consequently, it is considerably less expensive and simpler to develop, to operate, and to modify for flight experiments. It has different embedded technologies and a different operational concept. The flight testing will focus on RLV-type operations, the embedded technologies, and technology test articles to be carried as experiments.
Test-bed instrumentation will satisfy the needs for the embedded technolgoies demonstration, and for some ad***ional experiments to be carried. Ad***ional instrumentation requirements will be dictated by the demands of the experiments to be conducted.
This test-bed vehicle is designed to be air-launched from Orbital Science's L-1011 aircraft, then accelerated to speeds up to Mach 8, reaching altitudes up to 250,000 feet. It will land horizontally on a conventional runway. The X-34 will have a wing span of 27.7 feet and is 58.3 feet long.
The modular X-34 design permits easy engine removal and replacement. It may be adaptable for subsequent testing of more advanced propulsion technologies such as rocket based combined cycle, plug nozzle, pulse detonation wave rocket, and dual expansion engines.
The X-34 program is divided into two phases: In Phase I, the vehicle will be designed and built, and two envelope expansion flights limited to Mach 3.8 will be made. In Phase II, 25 flight throughout the range of achieveable speeds will be undertaken during a 12-month period, from locations selected to assure operational experience over a variety of weather and

X36X-36
McDonnell Douglas and the National Aeronautics and Space Administration (NASA) have developed a tailless research aircraft that could dramatically change the design of future stealthy fighters. Named the X-36, the vehicle has no vertical or horizontal tails and uses new split ailerons to provide yaw (left and right) and pitch (up and down) directional control. This innovative design promises to reduce weight, drag and radar signature and increase range, maneuverability and survivability of future fighter aircraft. The 28-percent scale prototype was designed, developed and produced in just 28 months for only $17 million. The X-36 began a six-month flight test program in the summer of 1996.
McDonnell Douglas and the National Aeronautics and Space Administration (NASA) embarked on a joint project in 1994 to develop a prototype fighter aircraft designed for stealth and agility. The result -- after only 28 months -- was a subscale tailless aircraft called the X-36. The 28 percent scale, remotely piloted X-36 has no vertical or horizontal tails, yet it is expected to be more maneuverable and agile than today's fighters. In ad***ion, the tailless design reduces the weight, drag and radar cross section typically associated with tra***ional fighter aircraft.
In a series of flight tests, the low-cost X-36 research vehicle demonstrated the feasibility of using new flight control technologies in place of vertical and horizontal tails to improve the maneuverability and survivability of future fighter aircraft. During flight, the X-36 used new split ailerons and a thrust-vectoring nozzle for directional control. The Ailerons not only split to provide yaw (right-left) control, but also raise and lower asymmetrically to provide roll control. The X-36 vehicle also incorporated an advanced, single-channel digital fly-by-wire control system developed with commercially available components.
Fully fueled, the X-36 prototype weighed 1,300 pounds. It is 19 feet long and measures 11 feet at its widest point. It is 3 feet high and is powered by a Williams Research F112 engine that provides about 700 pounds of thrust. Using a video camera in the nose of the vehicle, a pilot controls the flight of the X-36 from a virtual ****pit -- complete with head-up display (HUD) -- in a ground-based station. This pilot-in-the-loop approach eliminates the need for expensive and complex autonomous flight control systems.
McDonnell Douglas has been working under contract to NASA Ames Research Center, Moffett Field, Calif., since 1989 to develop the technical breakthroughs required to achieve tailless agile flight. Based on the positive results of extensive wind tunnel tests, McDonnell Douglas in 1993 proposed building a subscale tailless research aircraft. In 1994 McDonnell Douglas and NASA began joint funding of the development of this aircraft, now designated the X-36. Under the roughly 50/50 cost-share arrangement, NASA Ames is responsible for continued development of the critical technologies, and McDonnell Douglas for fabricating the aircraft.
McDonnell Douglas built the X-36 with a combination of advanced, lowcost design and manufacturing techniques pioneered by the company's Phantom Works research-and-development operation.
Among these techniques are:
advanced software development tools for rapid avionics prototyping;
low-cost tooling molds;
composite skins cured at low termperatures without the use of autoclaves, and;
high speed machining of unitized assemblies.
Two identical subscale research vehicles were produced by the team for use in the flight test program. Including design and production of the two aircraft and flight testing, the total cost of the X-36 program was only $17 million. A total of 25 flights, conducted by McDonnell Douglas, took place during a six-month flight test program designed to prove the aircraft's superior agility. Initial tests focused on the low-speed, high angle-of-attack performance of the X-36

X-37 / Future X / Advanced Technology Vehicle (ATV)
NASA is considering asking for funding for an X-37 flight test vehicle. This will provide the agency has a sustainable research and technology program in space transportation. There will be a need for a research vehicle after X-33. And one of the facts of the hypersonic or the very high speed vehicle business is that the place to validate systems and components is in-flight. So the team at Marshall and other centers, is working to put together a sustainable research and technology program with flight demonstration, where appropriate, in the investment strategy, that is called X-37 by some. The intended objective of the program is to demonstrate the next generation of technologies. The technologies in X-33 are frozen at 1994. Assuming success at this level of technology, the future requirements of NASA and the commercial industry are going to require a next generation of technologies, and NASA would be ready to develop those and to validate them in the X-37 experimental flight program. While the X-33 is a demonstrator for Earth-to-orbit technologies, Future X demonstrators will flight test technologies for multiple applications including orbital and commercial transport, military spaceplane, human exploration, multi-stage and hypersonics research.
In December 1998 NASA selected the Boeing Company, Downey, Calif., for negotiations leading to possible award of a four-year cooperative agreement to develop the first in a continuous series of advanced technology flight demonstrators called Future-X. The total value of the cooperative agreement, including NASA and Boeing contributions, is estimated at $150 million, with an approximate 50/50 sharing agreement.
Work conducted under this initiative may include:
Development of core technologies for low-cost space transportation.
Pathfinder vehicle flight tests to prove focused technologies that require a flight environment validation.
Trailblazer vehicles integrated flight demonstrations that validate a vareity of technologies and operations, along with performance and economic feasibility. Possible concepts include all-rocket and air-breathing systems, single and two-stage systems.
Work under this cooperative agreement will begin immediately after successful negotiations. In ad***ion, three companies and three NASA Centers were selected for seven Future-X flight experiments with an estimated value of $24 million. The Future-X effort is managed by the Space Transportation Programs Office at NASA's Marshall Space Fight Center, Huntsville, Ala.
Future-X vehicles and flight experiments will demonstrate technologies that improve performance and reduce development, production and operating costs of future Earth-to-orbit and in-space transportation systems. Under the cooperative agreement Boeing and NASA will advance 29 separate space transportation technologies through development and flight demonstrations of a modular orbital flight testbed called the Advanced Technology Vehicle (ATV). The ATV is first-ever experimental vehicle that will be flown in both orbital and reentry environments.