List of X-planes

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Bell X-1-2 BellX-1.jpeg
Bell X-1-2

The X-planes are a series of experimental United States aircraft and rockets, used to test and evaluate new technologies and aerodynamic concepts. They have an X designator within the US system of aircraft designations, which denotes the experimental research mission.

Contents

Not all US experimental aircraft have been designated as X-planes; some received US Navy designations before 1962, [1] while others have been known only by manufacturers' designations, [N 1] non-'X'-series designations, [N 2] or classified codenames. [N 3] This list only includes the designated X-planes.

History

The X-planes concept officially came into being in 1944, as a joint programme between the National Advisory Committee for Aeronautics (NACA), the US Navy (USN) and the US Army Air Forces (USAAF), in order to pursue research into high-speed aircraft. [2] NACA later became the National Aeronautics and Space Administration (NASA) and the USAAF became the United States Air Force (USAF). Other organizations such as the Defence Advanced Research Projects Agency (DARPA) and the US Marine Corps (USMC) have also since sponsored X-plane projects.

The first experimental aircraft specification, for a transonic rocket plane, was placed in 1945, and the first operational flight of an X-plane took place when the Bell X-1 made its first powered flight nearly three years later at Muroc Air Force Base, California, now known as Edwards Air Force Base. [3] The majority of X-plane testing has since taken place there. [4]

X-planes have since accomplished many aviation "firsts" including breaking speed and altitude barriers, varying wing sweep in flight, implementing exotic alloys and propulsion innovations, and many more. [2]

New X-planes appeared fairly regularly for many years until the flow temporarily stopped in the early 1970s. A series of experimental hypersonic projects, including an advanced version of the Martin Marietta X-24 lifting body, were turned down. Eventually issues with the Rockwell HiMAT advanced UAV led to a crewed X-plane with forward sweep, the Grumman X-29, which flew in 1984. [5]

Some of the X-planes have been well publicized, while others, such as the X-16, have been developed in secrecy. [6] The first, the Bell X-1, became well known in 1947 after it became the first aircraft to break the sound barrier in level flight. [7] Later X-planes supported important research in a multitude of aerodynamic and technical fields, but only the North American X-15 rocket plane of the early 1960s achieved comparable fame to that of the X-1.[ citation needed ] X-planes 8, 9, 11, 12, and 17 were actually missiles [8] used to test new types of engines, and some other vehicles were unoccupied or UAVs (some were remotely flown, some were partially or fully autonomous).

Most X-planes are not expected to go into full-scale production; one exception was the Lockheed Martin X-35, which competed against the Boeing X-32 during the Joint Strike Fighter Program, and has entered production as the F-35 Lightning II. [9]

List

In the list, the date is that of the first flight, or of cancellation if it never flew.

List of X-planes
ImageTypeManufacturerAgencyDateRoleNotes
Bell X-1 46-062 (in flight).jpg X-1 Bell USAF, NACA 1946High-speed and high-altitude flightFirst aircraft to break the sound barrier in level flight. Proved aerodynamic viability of thin wing sections. [10]
Bell X-1A.jpg X-1A X-1B X-1C X-1D BellUSAF, NACA1951High-speed and high-altitude flight
Joe Walker X-1E.jpg X-1E BellUSAF, NACA1955High-speed and high-altitude flight
X-2 After Drop from B-50 Mothership - GPN-2000-000396.jpg X-2 BellUSAF1952High-speed and high-altitude flightFirst aircraft to exceed Mach 3. [11]
Douglas X-3 NASA E-17348.jpg X-3 Stiletto Douglas USAF, NACA1952Highly loaded trapezoidal wing Titanium alloy construction; Underpowered, but provided insights into inertia coupling. [12]
Northrop-X4-Bantam.jpg X-4 Bantam Northrop USAF, NACA1948 Transonic tailless aircraft [13]
Bell-X5-Multiple.jpg X-5 BellUSAF, NACA1951 variable geometry First aircraft to fly with variable wing sweep. [14]
NB-36H producing contrails in flight.jpg X-6 Convair USAF, AEC 1957 Nuclear Propulsion Not built. The Convair NB-36H experiment, a B-36 modified to carry (but not powered by) a nuclear reactor, flew from 1955 to 1957. [15] [16]
X-7 USAF.jpg X-7 Lockheed USAF, USA, USN1951 Ramjet engines. [17]
AerojetX8.jpg X-8 Aerobee Aerojet NACA, USAF, USN1949Upper air research [18] Later models used as sounding rockets.
Bell X-9 trailer.jpg X-9 Shrike BellUSAF1949Guidance and propulsion technologyAssisted development of GAM-63 Rascal missile. [19]
North American X-10 runway.jpg X-10 North American USAF1953 SM-64 Navajo missile testbed. [20]
X-11 ConvairUSAF1953Proposed SM-65 Atlas missile testbed. [21]
X-12 ConvairUSAF1953Proposed SM-65 Atlas missile testbed. [22]
Ryan X-13.jpg X-13 Vertijet Ryan USAF, USN1955 Vertical takeoff and landing (VTOL) tailsitting VTOL flight. [23]
Bell X-14 colour ground.jpg X-14 BellUSAF, NASA1957VTOL Vectored thrust configuration for VTOL flight. [24]
X-15 in flight.jpg X-15 North AmericanUSAF, NASA1959 Hypersonic, high-altitude flightFirst crewed hypersonic aircraft; capable of suborbital spaceflight. [25]
X-15A2 NB-52B 3.jpg X-15A-2 North AmericanUSAF, NASA1964 Hypersonic, high-altitude flightMajor Pete Knight flew the X-15A-2 to a Mach 6.70, making it the fastest piloted flight of the X-plane program.
Bell X-16.jpg X-16 BellUSAF1954High-altitude reconnaissance [26] "X-16" designation used to hide true purpose. [27] Canceled and never flew.
Lockheed X-17 horizontal.jpg X-17 LockheedUSAF, USN1956High Mach number reentry. [28]
Hiller X-18 testplatformLarge.jpg X-18 Hiller USAF, USN1959Vertical and/or short take-off and landing (V/STOL)Evaluated the tiltwing concept for VTOL flight. [29]
Curtiss-Wright X-19 flying.jpg X-19 Curtiss-Wright Tri-service1963 Tandem tiltrotor VTOL [30] XC-143 designation requested but turned down. [31]
NASA Color Dyna Soar.jpg X-20 Dyna-Soar Boeing USAF1963Reusable spaceplane Intended for military missions. [32] Canceled and never built.
X21A.jpg X-21A NorthropUSAF1963 Boundary layer control [33]
X-22a onground bw.jpg X-22 BellTri-service1966Quad ducted fan tiltrotor STOVL [34]
X23 PRIME.JPG X-23 PRIME Martin Marietta USAF1966Maneuvering atmospheric reentry [35] Designation never officially assigned. [31]
X24.jpg X-24A Martin MariettaUSAF, NASA1969Low-speed lifting body [36]
X-24b-flying.jpg X-24B Martin MariettaUSAF, NASA1973Low-speed lifting body [37]
X-25.jpg X-25 Bensen USAF1955Commercial light autogyro for downed pilots. [38]
X-26 sailplane.jpg QT-2PCs in STAAF, RVN Hangar c1968.jpg X-26 Frigate Schweizer DARPA, US Army, USN1967Training glider for yaw-roll coupling Quiet observation aircraft [39]
X-27 mockup.jpg X-27 LockheedNone1971high-performance research aircraft. High-performance fighter [40] Proposed development of Lockheed CL-1200 Lancer. Canceled and never flew.
X-28 on ground.jpg X-28 Sea Skimmer Osprey USN1970Low-cost aerial policing seaplane [41]
Grumman-X29-InFlight.jpg X-29 Grumman DARPA, USAF, NASA1984 Forward-swept wing [42]
X-30 NASP 2.jpg X-30 NASP Rockwell NASA, DARPA, USAF1993 Single-stage-to-orbit spaceplane [43] Canceled and never built.
Rockwell-MBB X-31 landing.JPG X-31 Rockwell-MBBDARPA, USAF, BdV 1990 Thrust vectoring supermaneuverability [44]
USAF X32B 250.jpg X-32A BoeingUSAF, USN, USMC, RAF 2000 Joint Strike Fighter [45]
X-32B 2001
X-33 Venture Star in Orbit.jpg X-33 Lockheed Martin NASA2001Half-scale reusable launch vehicle prototype. [46] Prototype never completed.
Orbital Sciences X34.jpg X-34 Orbital Sciences NASA2001Reusable pilotless spaceplane. [47] Never flew.
X-35.jpg X-35A Lockheed MartinUSAF, USN, USMC, RAF 2000 Joint Strike Fighter [48]
X-35B Steven F. Udvar-Hazy Center.tif X-35B2001First in family to use VTOL. Also used unconventional mode of lift engine (lift fan).
Lockheed F-35 Joint Strike Fighter.jpg X-35C2000
Boeing-X36-InFlight.jpg X-36 McDonnell Douglas NASA199728% scale tailless fighter [49]
Boeing X-37B inside payload fairing before launch.jpg X-37 BoeingUSAF, USSF, NASA2010Reusable orbital spaceplane [50] Drop test performed in 2006. Seven flights to space since 22 April 2010
ISS Crew Return Vehicle.jpg X-38 Scaled Composites NASA1998Lifting body Crew Return Vehicle [51]
X-39 UnknownUSAFFuture Aircraft Technology Enhancements (FATE) program. [52] Designation never officially assigned. [31]
Boeing X40A.jpg X-40A BoeingUSAF, NASA199880% scale Space Maneuver Vehicle X-37 prototype. [53]
Early CAV concept 1997-98 NSSRM.jpg X-41 UnknownUSAFManeuvering re-entry vehicle. [54]
X-42 UnknownUSAFExpendable liquid propellant upper-stage rocket. [55]
X-43 NASA.jpg X-43 Hyper-X Micro-Craft NASA2001Hypersonic Scramjet [56]
X-44 Manta artistic impression.JPG X-44 MANTA Lockheed MartinUSAF, NASA2000 F-22-based Multi-Axis No-Tail Aircraft thrust vectoring [57] Canceled, never flew.
Boeing X-45A UCAV.jpg X-45 BoeingDARPA, USAF2002 Unmanned combat air vehicle (UCAV) [58]
X46.jpg X-46 BoeingDARPA, USN2003 Unmanned combat air vehicle (UCAV). [59] Naval use. Canceled, never flew.
X-47A rollout.jpg X-47A Pegasus Northrop GrummanDARPA, USN2003 Unmanned combat air vehicle (UCAV) [60] Naval use.
X-47B operating in the Atlantic Test Range (modified).jpg X-47B Northrop GrummanDARPA, USN2011UCAVNaval use.
X-47C Northrop GrummanUSAFManned bomberProposal for a new-generation strategic bomber. Design only.
ED06-0198-62.jpg X-48 BoeingNASA2007 Blended Wing Body (BWB) [61]
Piasecki X-49A.jpg X-49 SpeedHawk Piasecki US Army2007 Compound helicopter Vectored Thrust Ducted Propeller (VTDP) testbed. [62]
X-50 Dragonfly BoeingDARPA2003 Canard Rotor/Wing [63]
X51waverider.jpg X-51 Waverider BoeingUSAF2010 [64] Hypersonic scramjet [65]
—X-52————Number skipped to avoid confusion with Boeing B-52 Stratofortress. [31]
X-53 Active Aeroelastic Wing NASA test aircraft EC03-0039-1.jpg X-53 BoeingNASA, USAF2002Active Aeroelastic Wing [66]
X-54 Gulfstream NASALow-noise supersonic transport [67] in development.
Lockheed Martin X-55 ACCA 001.jpg X-55 Lockheed MartinUSAF2009Advanced Composite Cargo Aircraft (ACCA) [68]
Lockheed Martin X-56A.jpg X-56 Lockheed MartinUSAF/NASA2013Active flutter suppression and gust load alleviationPart of the high-altitude, long-endurance (HALE) reconnaissance aircraft program. [69]
X57-Maxwell-CGI.jpg X-57 Maxwell ESAero/Tecnam NASA2023Low emission plane powered entirely by electric motors [70] Part of NASA's Scalable Convergent Electric Propulsion Technology Operations Research project [70] (SCEPTOR). Cancelled in 2023, never flew.
—X-58————Number skipped; slot apparently assigned to Kratos XQ-58 Valkyrie. [71]
NASA's X-59 Sits on Ramp (AFRC2023-0198-03).jpg X-59 Quesst Lockheed MartinNASA2024Prototype quiet supersonic transport aircraft [72]
X-60 Generation Orbit Launch Services USAF Air-launched rocket for hypersonic flight research [73]
GremlinsFlightTestNovember2019.jpg X-61 Gremlins Dynetics DARPA2020Air-launched and air-recoverable reconnaissance unmanned air vehicle (UAV) [74] [75]
X-62 VISTA.jpg X-62 VISTA Lockheed Martin/CalspanUSAF2021Variable In-flight Simulator Test Aircraft.First flew in 1993 as the NF-16D (for the MATV program). Designated the X-62A during a major research system upgrade in 2021. Assigned to the USAF Test Pilot School. [76]
— X-63 ABL Space Systems AFRL 2023Modular aerospike engine launch vehicle testbed based on RS1. [77] The RS1 launch vehicle first flew on Jan 10, 2023. The launch ended in failure. [78]
—X-64Invocon Inc.AFRL—Modular aerospike engine launch vehicle testbed [77]
X-65 by DARPA.jpg X-65 CRANE Aurora Flight Sciences DARPA2025Control of Revolutionary Aircraft with Novel Effectors [79]
NASA Boeing X-66A Sustainable Flight Demonstrator side.jpg X-66 Boeing NASA2028Transonic Truss-Braced Wing [80]

See also

Notes

  1. ↑ For example, the Piasecki PA-97
  2. ↑ For example, the NASA AD-1 and Bell XV-15
  3. ↑ For example, the Northrop Tacit Blue

Related Research Articles

<span class="mw-page-title-main">Bell X-1</span> Experimental rocket-powered aircraft

The Bell X-1 is a rocket engine–powered aircraft, designated originally as the XS-1, and was a joint National Advisory Committee for Aeronautics–U.S. Army Air Forces–U.S. Air Force supersonic research project built by Bell Aircraft. Conceived during 1944 and designed and built in 1945, it achieved a speed of nearly 1,000 miles per hour in 1948. A derivative of this same design, the Bell X-1A, having greater fuel capacity and hence longer rocket burning time, exceeded 1,600 miles per hour in 1954. The X-1 aircraft #46-062, nicknamed Glamorous Glennis and flown by Chuck Yeager, was the first piloted airplane to exceed the speed of sound in level flight and was the first of the X-planes, a series of American experimental rocket planes designed for testing new technologies.

<span class="mw-page-title-main">North American X-15</span> Rocket-powered aircraft and spaceplane operated by the US Air Force and NASA

The North American X-15 is a hypersonic rocket-powered aircraft operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the X-plane series of experimental aircraft. The X-15 set speed and altitude records in the 1960s, crossing the edge of outer space and returning with valuable data used in aircraft and spacecraft design. The X-15's highest speed, 4,520 miles per hour, was achieved on 3 October 1967, when William J. Knight flew at Mach 6.7 at an altitude of 102,100 feet (31,120 m), or 19.34 miles. This set the official world record for the highest speed ever recorded by a crewed, powered aircraft, which remains unbroken.

<span class="mw-page-title-main">Boeing X-20 Dyna-Soar</span> Research spaceplane by Boeing

The Boeing X-20 Dyna-Soar was a United States Air Force (USAF) program to develop a spaceplane that could be used for a variety of military missions, including aerial reconnaissance, bombing, space rescue, satellite maintenance, and as a space interceptor to sabotage enemy satellites. The program ran from October 24, 1957, to December 10, 1963, cost US$660 million, and was cancelled just after spacecraft construction had begun.

<span class="mw-page-title-main">Lockheed YF-12</span> American prototype interceptor aircraft

The Lockheed YF-12 is an American Mach 3+ capable, high-altitude interceptor prototype, developed and manufactured by American aerospace company Lockheed Corporation.

<span class="mw-page-title-main">NASA X-43</span> Unmanned US experimental hypersonic aircraft, 1991-2000

The NASA X-43 was an experimental unmanned hypersonic aircraft with multiple planned scale variations meant to test various aspects of hypersonic flight. It was part of the X-plane series and specifically of NASA's Hyper-X program developed in the late 1990s. It set several airspeed records for jet aircraft. The X-43 is the fastest jet-powered aircraft on record at approximately Mach 9.6.

<span class="mw-page-title-main">Lockheed Martin X-44 MANTA</span> Conceptual aircraft design by Lockheed Martin

The Lockheed Martin X-44 MANTA was an American conceptual aircraft design by Lockheed Martin that has been studied by NASA and the U.S. Air Force. It was intended to test the feasibility of full yaw, pitch and roll authority without tailplanes. Attitude control would rely purely on 3D thrust vectoring. The aircraft design was derived from the F-22 Raptor and featured a stretched delta wing without tail surfaces.

<span class="mw-page-title-main">McDonnell Douglas X-36</span> Prototype jet

The McDonnell DouglasX-36Tailless Fighter Agility Research Aircraft is an American stealthy subscale prototype jet designed to fly without the traditional empennage found on most aircraft. This configuration was designed to reduce weight, drag and radar cross section, and increase range, maneuverability and survivability.

<span class="mw-page-title-main">Joseph A. Walker</span> American test pilot

Joseph Albert Walker was an American World War II pilot, experimental physicist, NASA test pilot, and astronaut who was the first person to fly an airplane to space. He was one of twelve pilots who flew the North American X-15, an experimental spaceplane jointly operated by the Air Force and NASA.

<span class="mw-page-title-main">Air Force Research Laboratory</span> Scientific research organization for the US Air Force and US Space Force

The Air Force Research Laboratory (AFRL) is a scientific research and development detachment of the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of direct-energy based aerospace warfighting technologies, planning and executing the Air Force science and technology program, and providing warfighting capabilities to United States air, space, and cyberspace forces. It controls the entire Air Force science and technology research budget which was $2.4 billion in 2006.

<span class="mw-page-title-main">Lockheed D-21</span> 1962 American Mach 3+ reconnaissance drone

The Lockheed D-21 is an American supersonic reconnaissance drone. The D-21 was initially designed to be launched from the back of an M-21 carrier aircraft, a variant of the Lockheed A-12 aircraft. The drone had maximum speed in excess of Mach 3.3 at an operational altitude of 90,000 feet. Development began in October 1962. Originally known by the Lockheed designation Q-12, the drone was intended for reconnaissance deep into enemy airspace.

<span class="mw-page-title-main">Boeing X-48</span> Airplane

The Boeing X-48 is an American experimental unmanned aerial vehicle (UAV) built to investigate the characteristics of blended wing body (BWB) aircraft. Boeing designed the X-48 and two examples were built by Cranfield Aerospace in the UK. Boeing began flight testing the X-48B version for NASA in 2007. The X-48B was later modified into the X-48C version, which was flight tested from August 2012 to April 2013. Boeing and NASA plan to develop a larger BWB demonstrator.

<span class="mw-page-title-main">Aerojet General X-8</span> Experimental spin-stabilized rocket for very high altitude research

The Aerojet General X-8 was an unguided, spin-stabilized sounding rocket designed to launch a 150 lb (68 kg) payload to 200,000 feet (61.0 km). The X-8 was a version of the prolific Aerobee rocket family.

<span class="mw-page-title-main">Rockwell X-30</span> US NASA & DOD hypersonic project in 1986–1993

The Rockwell X-30 was an advanced technology demonstrator project for the National Aero-Space Plane (NASP), part of a United States project to create a single-stage-to-orbit (SSTO) spacecraft and passenger spaceliner. Started in 1986, it was cancelled in the early 1990s before a prototype was completed, although much development work in advanced materials and aerospace design was completed. While a goal of a future NASP was a passenger liner capable of two-hour flights from Washington to Tokyo, the X-30 was planned for a crew of two and oriented towards testing.

<span class="mw-page-title-main">DARPA Falcon Project</span> US program to develop a hypersonic weapon

The DARPA FALCON Project was a two-part joint project between the Defense Advanced Research Projects Agency (DARPA) and the United States Air Force (USAF) and is part of Prompt Global Strike. The first part of the project aimed to develop a Small Launch System (SLS) capable of accelerating hypersonic gliding weapons as well as launching small satellites into Earth orbit. The second part of the project aimed to develop Hypersonic Weapon Systems (HWS): a short term high performance hypersonic gliding weapon previously named the X-41 Common Aero Vehicle (CAV) that could be launched from Expendable Launch Vehicles (ELV), Reusable Launch Vehicles (RLVs), Hypersonic Cruise Vehicles (HCV), or Space Maneuvering Vehicles (SMP), and a long term hypersonic cruise aircraft named the Hypersonic Cruise Vehicle (HCV). This two-part program was announced in 2003 and continued into 2006.

<span class="mw-page-title-main">Boeing X-51 Waverider</span> Unmanned hypersonic experimental aircraft

The Boeing X-51 Waverider is an unmanned research scramjet experimental aircraft for hypersonic flight at Mach 5 and an altitude of 70,000 feet (21,000 m). The aircraft was designated X-51 in 2005. It completed its first powered hypersonic flight on 26 May 2010. After two unsuccessful test flights, the X-51 completed a flight of over six minutes and reached speeds of over Mach 5 for 210 seconds on 1 May 2013 for the longest duration powered hypersonic flight.

Scramjet programs refers to research and testing programs for the development of supersonic combustion ramjets, known as scramjets. This list provides a short overview of national and international collaborations, and civilian and military programs. The USA, Russia, India, and China (2014), have succeeded at developing scramjet technologies.

<span class="mw-page-title-main">Lockheed L-301</span>

Lockheed L-301 was an experimental air-breathing hypersonic aircraft project. It was developed by the NASA and United States Air Force (USAF) organization National Hypersonic Flight Research Facility, with Skunk Works as the prime contractor. In January 1977, the program was "tentatively scheduled to operate two vehicles for eight years and to conduct 100 flights per vehicle." NASA discontinued work on L-301 and NHRF in September 1977 due to budget constraints and lack of need.

<span class="mw-page-title-main">Alpha Draco</span> Experimental ballistic missile

The Alpha Draco missile, also known as Weapons System 199D (WS-199D), was an experimental ballistic missile developed by McDonnell Aircraft in the late 1950s to investigate the aerodynamic physics of the boost-glide reentry trajectory. Three test flights were conducted in 1959, of which two were successful.

<span class="mw-page-title-main">Have Dash</span> Air-to-air missile

Have Dash was a program conducted by the United States Air Force for the development of a stealthy air-to-air missile. Although the Have Dash II missile appears to have been flight tested, the results of the project remain classified, and no mass production is known to have been undertaken.

References

  1. ↑ "D-558-I" NASA Dryden Fact Sheets. NASA. Accessed May 8, 2010.
  2. 1 2 Miller 1983, p.9.
  3. ↑ Miller 1983, pp.15-17.
  4. ↑ "X-Planes Experimental Aircraft". Federation of American Scientists . Retrieved 1 June 2012.
  5. ↑ Miller 1983, p.13.
  6. ↑ Miller 2001, p. 209
  7. ↑ First Generation X-1 (fact sheet), Dryden: NASA , retrieved 8 May 2010.
  8. ↑ Jenkins, Landis & Miller 2003, p. 14,15,17,18,24.
  9. ↑ A history of the Joint Strike Fighter Program, UK: Martin-Baker, January 2010, archived from the original on 30 December 2010.
  10. ↑ Jenkins, Landis & Miller 2003, p. 5–7.
  11. ↑ Jenkins, Landis & Miller 2003, p. 8.
  12. ↑ Jenkins, Landis & Miller 2003, p. 9.
  13. ↑ Jenkins, Landis & Miller 2003, p. 10.
  14. ↑ Jenkins, Landis & Miller 2003, p. 11.
  15. ↑ Jenkins, Landis & Miller 2003, p. 12.
  16. ↑ Miller 1983.
  17. ↑ Jenkins, Landis & Miller 2003, p. 13.
  18. ↑ Jenkins, Landis & Miller 2003, p. 14.
  19. ↑ Jenkins, Landis & Miller 2003, p. 15.
  20. ↑ Jenkins, Landis & Miller 2003, p. 16.
  21. ↑ Jenkins, Landis & Miller 2003, p. 17.
  22. ↑ Jenkins, Landis & Miller 2003, p. 18.
  23. ↑ Jenkins, Landis & Miller 2003, p. 19.
  24. ↑ Jenkins, Landis & Miller 2003, p. 20.
  25. ↑ Jenkins, Landis & Miller 2003, p. 21–22.
  26. ↑ Jenkins, Landis & Miller 2003, p. 23.
  27. ↑ "X-16". Global security, accessed 11 May 2010.
  28. ↑ Jenkins, Landis & Miller 2003, p. 24.
  29. ↑ Jenkins, Landis & Miller 2003, p. 25.
  30. ↑ Jenkins, Landis & Miller 2003, p. 26.
  31. 1 2 3 4 Parsch 2024, "Missing Designations"
  32. ↑ Jenkins, Landis & Miller 2003, p. 27.
  33. ↑ Jenkins, Landis & Miller 2003, p. 28.
  34. ↑ Jenkins, Landis & Miller 2003, p. 29.
  35. ↑ Jenkins, Landis & Miller 2003, p. 30.
  36. ↑ Jenkins, Landis & Miller 2003, p. 31.
  37. ↑ Jenkins, Landis & Miller 2003, p. 32.
  38. ↑ Jenkins, Landis & Miller 2003, p. 33.
  39. ↑ Jenkins, Landis & Miller 2003, p. 34.
  40. ↑ Jenkins, Landis & Miller 2003, p. 35.
  41. ↑ Jenkins, Landis & Miller 2003, p. 36.
  42. ↑ Jenkins, Landis & Miller 2003, p. 37.
  43. ↑ Jenkins, Landis & Miller 2003, p. 38.
  44. ↑ Jenkins, Landis & Miller 2003, p. 39.
  45. ↑ Jenkins, Landis & Miller 2003, p. 40–41.
  46. ↑ Jenkins, Landis & Miller 2003, p. 42.
  47. ↑ Jenkins, Landis & Miller 2003, p. 43.
  48. ↑ Jenkins, Landis & Miller 2003, p. 44–45.
  49. ↑ Jenkins, Landis & Miller 2003, p. 46.
  50. ↑ Jenkins, Landis & Miller 2003, p. 47.
  51. ↑ Jenkins, Landis & Miller 2003, p. 48.
  52. ↑ Jenkins, Landis & Miller 2003, p. 49.
  53. ↑ Jenkins, Landis & Miller 2003, p. 50.
  54. ↑ Jenkins, Landis & Miller 2003, p. 51.
  55. ↑ Jenkins, Landis & Miller 2003, p. 52.
  56. ↑ Jenkins, Landis & Miller 2003, p. 53.
  57. ↑ Jenkins, Landis & Miller 2003, p. 54.
  58. ↑ Jenkins, Landis & Miller 2003, p. 55.
  59. ↑ Jenkins, Landis & Miller 2003, p. 56.
  60. ↑ Jenkins, Landis & Miller 2003, p. 57.
  61. ↑ Jenkins, Landis & Miller 2003, p. 58.
  62. ↑ Parsch 2024, "DOD 4120.15-L"
  63. ↑ Jenkins, Landis & Miller 2003, p. 60.
  64. ↑ "X-51 Waverider makes historic hypersonic flight". US Air Force Public Affairs. 26 May 2010. Retrieved 27 May 2010.
  65. ↑ "X-51 Scramjet Engine Demonstrator - WaveRider" globalsecurity.org. Accessed 2010-05-11.
  66. ↑ Jordan 2006
  67. ↑ 412015-L
  68. ↑ Kaufman 2009
  69. ↑ Norris 2012
  70. 1 2 Harrington, J.D.; Kamlet, Matt; Barnstorff, Kathy (17 June 2016). "NASA Hybrid Electric Research Plane Gets X Number, New Name". NASA.gov. NASA. Retrieved 17 June 2016.
  71. ↑ The Air Force Valkyrie Drone, a Sidekick for Human-Piloted Planes, Will Fly This Year
  72. ↑ Jim, Banke (27 June 2018). "NASA's Experimental Supersonic Aircraft Now Known as X-59 QueSST". NASA. Retrieved 28 June 2018.
  73. ↑ "U.S. Air Force Designates GO1 Hypersonic Flight Research Vehicle as X-60A". generationorbit.com. 4 October 2018. Retrieved 4 October 2018.
  74. ↑ "Earthquake damage delays Gremlins trial". Flight International. 24 September 2019. Retrieved 28 October 2019.
  75. ↑ "Dynetics X-61A Gremlins makes first flight, but destroyed after parachute fails". Flight International. 17 January 2020. Retrieved 13 February 2020.
  76. ↑ Giancarlo Casem (30 Jul 2021) NF-16D VISTA becomes X-62A, paves way for Skyborg autonomous flight tests
  77. 1 2 "AFRL's Rocket Lab Past, Present and Future". AFRL. Retrieved 25 August 2024.
  78. ↑ "ABL Space Systems' rocket fails on maiden launch". Reuters. 11 January 2023. Archived from the original on 11 January 2023. Retrieved 11 January 2023.
  79. ↑ Hadley, Greg (16 May 2023). "Meet the X-65: DARPA's New Plane Has No External Control Surfaces". Air & Space Forces Magazine. Retrieved 29 May 2023.
  80. ↑ O’Shea, Claire (12 June 2023). "Next Generation Experimental Aircraft Becomes NASA's Newest X-Plane". NASA. Retrieved 13 June 2023.

Bibliography

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