152 relations: Aerojet, Aerojet General X-8, Aircraft, Aircraft Nuclear Propulsion, Atmospheric entry, Autogyro, Bell Aircraft, Bell X-1, Bell X-14, Bell X-16, Bell X-2, Bell X-22, Bell X-5, Bell X-9 Shrike, Bell XV-15, Bensen Aircraft, Bensen B-8, Blended wing body, Boeing, Boeing B-52 Stratofortress, Boeing X-20 Dyna-Soar, Boeing X-32, Boeing X-37, Boeing X-40, Boeing X-45, Boeing X-46, Boeing X-48, Boeing X-50 Dragonfly, Boeing X-51 Waverider, Boeing X-53 Active Aeroelastic Wing, Boundary layer control, Convair, Convair X-6, Crew Return Vehicle, Curtiss-Wright, Curtiss-Wright X-19, DARPA, Douglas Aircraft Company, Douglas X-3 Stiletto, Ducted fan, Dutch roll, Edwards Air Force Base, Experimental aircraft, Federal Ministry of Defence (Germany), Federation of American Scientists, Forward-swept wing, Future Aircraft Technology Enhancements, GAM-63 RASCAL, Glider (aircraft), Grumman, ..., Grumman X-29, Gulfstream Aerospace, Gulfstream X-54, Gyrodyne, Hiller Aircraft, Hiller X-18, Hypersonic speed, Inertia coupling, Joint Strike Fighter program, Lifting body, Liquid-propellant rocket, List of experimental aircraft, List of military aircraft of the United States, List of military aircraft of the United States (naval), Lockheed CL-1200 Lancer, Lockheed Corporation, Lockheed Martin, Lockheed Martin F-22 Raptor, Lockheed Martin F-35 Lightning II, Lockheed Martin X-33, Lockheed Martin X-35, Lockheed Martin X-44 MANTA, Lockheed Martin X-55, Lockheed Martin X-56, Lockheed Martin X-59 QueSST, Lockheed X-17, Lockheed X-7, Mach number, Martin Marietta, Martin Marietta X-24, Martin X-23 PRIME, McDonnell Douglas, McDonnell Douglas X-36, Missile, NASA, NASA AD-1, NASA X-38, NASA X-43, NASA X-57 Maxwell, National Advisory Committee for Aeronautics, North American Aviation, North American X-10, North American X-15, Northrop Corporation, Northrop Grumman X-47A Pegasus, Northrop Grumman X-47B, Northrop Tacit Blue, Northrop X-21, Northrop X-4 Bantam, Orbital Sciences Corporation, Orbital Sciences X-34, Osprey Osprey I, Piasecki Aircraft, Piasecki PA-97, Piasecki X-49, Quadcopter, Ramjet, Reconnaissance aircraft, Reusable launch system, Rocket, Rocket-powered aircraft, Rockwell International, Rockwell X-30, Rockwell-MBB X-31, Rotorcraft, Royal Air Force, Ryan Aeronautical, Ryan X-13 Vertijet, Scaled Composites, Schweizer Aircraft, Schweizer X-26 Frigate, Scramjet, Single-stage-to-orbit, SM-64 Navaho, SM-65 Atlas, SM-65A Atlas, SM-65B Atlas, Sound barrier, Spaceplane, Supermaneuverability, Supersonic transport, Surveillance aircraft, Tail-sitter, Tailless aircraft, Tecnam, Thrust vectoring, Tiltrotor, Tiltwing, Titanium, Transonic, United Kingdom, United States, United States Air Force, United States Army, United States Atomic Energy Commission, United States Department of Defense aerospace vehicle designation, Unmanned combat aerial vehicle, V/STOL, Variable-sweep wing, VTOL, X-41 Common Aero Vehicle, X-42 Pop-Up Upper Stage. Expand index (102 more) » « Shrink index
Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas.
The Aerojet General X-8 was an unguided, spin-stabilized sounding rocket designed to launch a payload to.
An aircraft is a machine that is able to fly by gaining support from the air.
The Aircraft Nuclear Propulsion (ANP) program and the preceding Nuclear Energy for the Propulsion of Aircraft (NEPA) project worked to develop a nuclear propulsion system for aircraft.
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet or natural satellite.
An autogyro (from Greek αὐτός and γύρος, "self-turning"), also known as a gyroplane or gyrocopter, is a type of rotorcraft that uses an unpowered rotor in free autorotation to develop lift.
The Bell Aircraft Corporation was an aircraft manufacturer of the United States, a builder of several types of fighter aircraft for World War II but most famous for the Bell X-1, the first supersonic aircraft, and for the development and production of many important civilian and military helicopters.
The Bell X-1 was 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.
The Bell X-14 (Bell Type 68) was an experimental VTOL aircraft flown in the United States in the 1950s.
The Bell X-16 was a high altitude reconnaissance jet aircraft designed in the United States in the 1950s.
The Bell X-2 (nicknamed "Starbuster") was an X-plane research aircraft built to investigate flight characteristics in the Mach 2–3 range.
The Bell X-22 was an American V/STOL X-plane with four tilting ducted fans.
The Bell X-5 was the first aircraft capable of changing the sweep of its wings in flight.
The Bell X-9 Shrike was a prototype surface-to-air, liquid-fueled guided missile designed by Bell Aircraft as a testbed for the nuclear-armed GAM-63 RASCAL.
The Bell XV-15 is an American tiltrotor VTOL aircraft.
The Bensen Aircraft Corporation was established by Dr.
The Bensen B-8 is a small, single-seat autogyro developed in the United States in the 1950s.
A Blended wing body (BWB or Hybrid Wing Body, HWB) is a fixed-wing aircraft having no clear dividing line between the wings and the main body of the craft.
The Boeing Company is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide.
The Boeing B-52 Stratofortress is an American long-range, subsonic, jet-powered strategic bomber.
The Boeing X-20 Dyna-Soar ("Dynamic Soarer") 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 Boeing X-32 was a concept demonstrator aircraft in the Joint Strike Fighter contest.
The Boeing X-37, also known as the Orbital Test Vehicle (OTV), is a reusable uncrewed spacecraft.
The Boeing X-40A Space Maneuver Vehicle was a test platform for the X-37 Future-X Reusable Launch Vehicle.
The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works.
The Boeing X-46 was a proposed unmanned combat air vehicle (UCAV) that was to be developed in conjunction with the U.S. Navy and DARPA as a naval carrier-based variant of the Boeing X-45 UCAV being developed for the U.S. Air Force.
The Boeing X-48 is an American experimental unmanned aerial vehicle (UAV) built to investigate the characteristics of blended wing body (BWB) aircraft, a type of flying wing.
The Boeing X-50A Dragonfly, formerly known as the Canard Rotor/Wing Demonstrator, was a VTOL rotor wing experimental unmanned aerial vehicle that was developed by Boeing and DARPA to demonstrate the principle that a helicopter's rotor could be stopped in flight and act as a fixed wing, enabling it to transition between fixed-wing and rotary-wing flight.
The Boeing X-51 Waverider is an unmanned research scramjet experimental aircraft for hypersonic flight at and an altitude of.
The X-53 Active Aeroelastic Wing (AAW) development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory (AFRL), Boeing Phantom Works and NASA's Dryden Flight Research Center, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet.
Boundary layer control refers to methods of controlling the behaviour of fluid flow boundary layers.
Convair was an American aircraft manufacturing company which later expanded into rockets and spacecraft.
The Convair X-6 was a proposed experimental aircraft project to develop and evaluate a nuclear-powered jet aircraft.
The Crew Return Vehicle (CRV), sometimes referred to as the Assured Crew Return Vehicle (ACRV), was a proposed dedicated lifeboat or escape module for the International Space Station (ISS).
The Curtiss-Wright Corporation is an American-based, global diversified product manufacturer and service provider for the commercial, industrial, defense, and energy markets.
The Curtiss-Wright X-19 was an American experimental VTOL tilt propeller airplane of the early 1960s.
The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military.
The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California.
The Douglas X-3 Stiletto was a 1950s United States experimental jet aircraft with a slender fuselage and a long tapered nose, manufactured by the Douglas Aircraft Company.
A ducted fan is a propulsion arrangement whereby a mechanical fan, which is a type of propeller, is mounted within a cylindrical shroud or duct.
Dutch roll is a type of aircraft motion, consisting of an out-of-phase combination of "tail-wagging" and rocking from side to side.
Edwards Air Force Base (AFB) is a United States Air Force installation located in Kern County in southern California, about northeast of Lancaster and east of Rosamond.
An experimental aircraft is an aircraft that has not yet been fully proven in flight.
The Federal Ministry of Defence (Bundesministerium der Verteidigung), abbreviated BMVg, is a top-level federal agency, headed by the Federal Minister of Defence as a member of the Cabinet of Germany.
The Federation of American Scientists (FAS) is a 501(c)(3) organization with the stated intent of using science and scientific analysis to attempt to make the world more secure.
A forward-swept wing is an aircraft wing configuration in which the quarter-chord line of the wing has a forward sweep.
The Future Aircraft Technology Enhancements (FATE) program is a program to develop new technologies.
The GAM-63 RASCAL was a supersonic air-to-surface missile that was developed by the Bell Aircraft Company.
A glider is a heavier-than-air aircraft that is supported in flight by the dynamic reaction of the air against its lifting surfaces, and whose free flight does not depend on an engine.
The Grumman Aircraft Engineering Corporation, later Grumman Aerospace Corporation, was a leading 20th century U.S. producer of military and civilian aircraft.
The Grumman X-29 was an American experimental aircraft that tested a forward-swept wing, canard control surfaces, and other novel aircraft technologies.
Gulfstream Aerospace Corporation is an American wholly owned subsidiary of General Dynamics.
The Gulfstream X-54 is a proposed research and demonstration aircraft, under development in the United States by Gulfstream Aerospace for NASA, that is planned for use in sonic boom and supersonic transport research.
A gyrodyne is a type of VTOL aircraft with a helicopter rotor-like system that is driven by its engine for takeoff and landing and also includes one or more conventional propellers to provide forward thrust during cruising flight.
Hiller Aircraft Company was founded in 1942 as Hiller Industries by Stanley Hiller to develop helicopters.
The Hiller X-18 was an experimental cargo transport aircraft designed to be the first testbed for tiltwing and V/STOL (vertical/short takeoff and landing) technology.
In aerodynamics, a hypersonic speed is one that is highly supersonic.
In aeronautics, inertia coupling is a potentially catastrophic phenomenon of high-speed flight in which the inertia of the heavier fuselage overpowers the aerodynamic stabilizing forces of the wing and empennage.
Joint Strike Fighter (JSF) is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Turkey, Italy, Canada, Australia, the Netherlands and their allies.
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift.
A liquid-propellant rocket or liquid rocket is a rocket engine that uses liquid propellants.
This is a list of experimental aircraft, or aircraft used or built to conduct experiments involving aerodynamics, structural materials, propulsion systems, configuration and equipment.
This list of military aircraft of the United States includes prototype, pre-production, and operational types.
This list of military aircraft of the United States (naval) includes prototype, pre-production and operational types designations under the 1922 United States Navy aircraft designation system, which was used by the United States Navy, the United States Marine Corps, and the United States Coast Guard.
The Lockheed CL-1200 Lancer was a late 1960s company-funded proposal for an improved Lockheed F-104 Starfighter.
The Lockheed Corporation was an American aerospace company.
Lockheed Martin is an American global aerospace, defense, security and advanced technologies company with worldwide interests.
The Lockheed Martin F-22 Raptor is a fifth-generation, single-seat, twin-engine, all-weather stealth tactical fighter aircraft developed for the United States Air Force (USAF).
The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters.
The Lockheed Martin X-33 was an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program.
The Lockheed Martin X-35 was a concept demonstrator aircraft (CDA) developed by Lockheed Martin for the Joint Strike Fighter program.
The Lockheed Martin X-44 MANTA (Multi-Axis No-Tail Aircraft) was a conceptual aircraft design by Lockheed Martin that has been studied by NASA and the U.S. Air Force.
The Lockheed Martin X-55 Advanced Composite Cargo Aircraft (ACCA) is an experimental twinjet transport aircraft.
The Lockheed Martin X-56 is an American modular unmanned aerial vehicle that is being designed to explore High-Altitude Long Endurance (HALE) flight technologies for use in future military unmanned reconnaissance aircraft.
The Lockheed Martin X-59 is an American experimental supersonic aircraft being developed for NASA's Low-Boom Flight Demonstrator program.
The Lockheed X-17 was a three-stage solid-fuel research rocket to test the effects of high mach atmospheric reentry.
The Lockheed X-7 (dubbed the "Flying Stove Pipe") was an American unmanned test bed of the 1950s for ramjet engines and missile guidance technology.
In fluid dynamics, the Mach number (M or Ma) is a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound.
The Martin Marietta Corporation was an American company founded in 1961 through the merger of Glenn L. Martin Company and American Marietta Corporation.
The Martin Marietta X-24 was an American experimental aircraft developed from a joint United States Air Force-NASA program named PILOT (1963–1975).
The Martin X-23A PRIME (Precision Reentry Including Maneuvering reEntry) (SV-5D) was a small lifting-body re-entry vehicle tested by the United States Air Force in the mid-1960s.
McDonnell Douglas was a major American aerospace manufacturing corporation and defense contractor formed by the merger of McDonnell Aircraft and the Douglas Aircraft Company in 1967.
The McDonnell Douglas (later Boeing) X-36 Tailless Fighter Agility Research Aircraft was an American subscale prototype jet designed to fly without the traditional tail assembly found on most aircraft.
In modern language, a missile is a guided self-propelled system, as opposed to an unguided self-propelled munition, referred to as a rocket (although these too can also be guided).
The National Aeronautics and Space Administration (NASA) is an independent agency of the executive branch of the United States federal government responsible for the civilian space program, as well as aeronautics and aerospace research.
The NASA AD-1 was both an aircraft and an associated flight test program conducted between 1979 and 1982 at the NASA Dryden Flight Research Center, Edwards California, which successfully demonstrated an aircraft wing that could be pivoted obliquely from zero to 60 degrees during flight.
The X-38 was an experimental re-entry vehicle designed by NASA to research a possible emergency crew return vehicle (CRV) for the International Space Station (ISS).
The X-43 was an experimental unmanned hypersonic aircraft with multiple planned scale variations meant to test various aspects of hypersonic flight.
The NASA X-57 Maxwell is an experimental aircraft being developed by NASA, intended to demonstrate technology to reduce fuel use, emissions, and noise.
The National Advisory Committee for Aeronautics (NACA) was a U.S. federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research.
North American Aviation (NAA) was a major American aerospace manufacturer, responsible for a number of historic aircraft, including the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-86 Sabre jet fighter, the X-15 rocket plane, and the XB-70, as well as Apollo Command and Service Module, the second stage of the Saturn V rocket, the Space Shuttle orbiter and the B-1 Lancer.
The North American X-10 (model RTV-A-5) was an unmanned technology demonstrator, developed by North American Aviation.
The North American X-15 was a hypersonic rocket-powered aircraft operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft.
Northrop Corporation was a leading United States aircraft manufacturer from its formation in 1939 until its 1994 merger with Grumman to form Northrop Grumman.
The Northrop Grumman X-47 is a demonstration Unmanned Combat Aerial Vehicle.
The Northrop Grumman X-47B is a demonstration unmanned combat air vehicle (UCAV) designed for aircraft carrier-based operations.
The Northrop Tacit Blue was a technology demonstrator aircraft created to demonstrate that a low-observable stealth surveillance aircraft with a low probability of intercept radar and other sensors could operate close to the forward line of battle with a high degree of survivability.
The Northrop X-21A was an experimental aircraft designed to test wings with laminar flow control.
The Northrop X-4 Bantam was a prototype small twinjet aircraft manufactured by Northrop Corporation in 1948.
Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture and launch of small- and medium- class space and rocket systems for commercial, military and other government customers.
The Orbital Sciences X-34 was intended to be a low-cost testbed for demonstrating "key technologies" which could be integrated into the Reusable Launch Vehicle program.
The Osprey GP2 Osprey, also known as the Air Skimmer, Sea Skimmer, or Pereira GP2 Osprey, was a single-seat flying boat designed by Eut Tileston under contract to George Pereira, a private builder.
The Piasecki Aircraft Corporation (PiAC) was founded by American vertical flight pioneer Frank Piasecki to develop compound helicopters and other advanced rotorcraft after he was ousted from the leadership of his first company, Piasecki Helicopter, which was renamed Vertol Corporation and later acquired by Boeing.
The Piasecki PA-97 Helistat was an American experimental heavy-lift aircraft, built by Piasecki by fastening four H-34J helicopters to a framework beneath a helium-inflated blimp envelope.
The Piasecki X-49 "SpeedHawk" is an American four-bladed, twin-engined experimental high-speed compound helicopter under development by Piasecki Aircraft.
A quadcopter, also called a quadrotor helicopter or quadrotor, is a multirotor helicopter that is lifted and propelled by four rotors.
A ramjet, sometimes referred to as a flying stovepipe or an athodyd (an abbreviation of aero thermodynamic duct), is a form of airbreathing jet engine that uses the engine's forward motion to compress incoming air without an axial compressor or a centrifugal compressor.
A reconnaissance aircraft is a military aircraft designed or adapted to perform aerial reconnaissance.
A reusable launch system (RLS, or reusable launch vehicle, RLV) is a space launch system intended to allow for recovery of all or part of the system for later reuse.
A rocket (from Italian rocchetto "bobbin") is a missile, spacecraft, aircraft or other vehicle that obtains thrust from a rocket engine.
A rocket-powered aircraft or rocket plane is an aircraft that uses a rocket engine for propulsion, sometimes in addition to airbreathing jet engines.
Rockwell International was a major American manufacturing conglomerate in the latter half of the 20th century, involved in aircraft, the space industry, both defense-oriented and commercial electronics, automotive and truck components, printing presses, valves and meters, and industrial automation.
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.
The Rockwell-Messerschmitt-Bölkow-Blohm X-31 was an experimental jet fighter designed to test fighter thrust vectoring technology.
A rotorcraft or rotary-wing aircraft is a heavier-than-air flying machine that uses lift generated by wings, called rotary wings or rotor blades, that revolve around a mast.
The Royal Air Force (RAF) is the United Kingdom's aerial warfare force.
The Ryan Aeronautical Company was founded by T. Claude Ryan in San Diego, California in 1934.
The Ryan X-13 Vertijet (company designation Model 69) was an experimental vertical take-off and landing (VTOL) jet aircraft flown in the United States in the 1950s.
Scaled Composites (often called simply Scaled) is an American aerospace company founded by Burt Rutan and currently owned by Northrop Grumman that is located at the Mojave Air and Space Port, Mojave, California, United States.
The Schweizer Aircraft Corporation was an American manufacturer of sailplanes, agricultural aircraft and helicopters located in Horseheads, New York.
The X-26 Frigate is the longest-lived of the X-plane programs.
A scramjet ("supersonic combustion ramjet") is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow.
A single-stage-to-orbit (or SSTO) vehicle reaches orbit from the surface of a body without jettisoning hardware, expending only propellants and fluids.
The North American SM-64 Navaho was a supersonic intercontinental cruise missile project built by North American Aviation (NAA).
The SM-65 Atlas was the first operational intercontinental ballistic missile (ICBM) developed by the United States and the first member of the Atlas rocket family.
The Convair SM-65A Atlas, or Atlas A was the first full-scale prototype of the Atlas missile, which first flew on 11 June 1957.
The Convair SM-65B Atlas, or Atlas B, also designated X-12 was a prototype of the Atlas missile.
The sound barrier or sonic barrier is a popular term for the sudden increase in aerodynamic drag and other effects experienced by an aircraft or other object when it approaches supersonic speed.
A spaceplane is an aerospace vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space.
Supermaneuverability is the ability of aircraft to maintain pilot control and perform maneuvers in situations and ways exceeding those that are possible using purely aerodynamic mechanisms.
A supersonic transport (SST) is a civilian supersonic aircraft designed to transport passengers at speeds greater than the speed of sound.
A surveillance aircraft is an aircraft used for surveillance—collecting information over time.
A tail-sitter or tailsitter is a type of VTOL aircraft that takes off and lands on its tail, then tilts horizontally for forward flight.
A tailless aircraft has no tail assembly and no other horizontal surface besides its main wing.
Costruzioni Aeronautiche Tecnam is an Italian aeronautics manufacturer.
Thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket, or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) in order to control the attitude or angular velocity of the vehicle.
A tiltrotor is an aircraft which generates lift and propulsion by way of one or more powered rotors (sometimes called proprotors) mounted on rotating engine pods or nacelles usually at the ends of a fixed wing or an engine mounted in the fuselage with drive shafts transferring power to rotor assemblies mounted on the wingtips.
A tiltwing aircraft features a wing that is horizontal for conventional forward flight and rotates up for vertical takeoff and landing.
Titanium is a chemical element with symbol Ti and atomic number 22.
In aeronautics, transonic (or transsonic) flight is flying at or near the speed of sound (at sea level under average conditions), relative to the air through which the vehicle is traveling.
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,Usage is mixed with some organisations, including the and preferring to use Britain as shorthand for Great Britain is a sovereign country in western Europe.
The United States of America (USA), commonly known as the United States (U.S.) or America, is a federal republic composed of 50 states, a federal district, five major self-governing territories, and various possessions.
The United States Air Force (USAF) is the aerial and space warfare service branch of the United States Armed Forces.
The United States Army (USA) is the land warfare service branch of the United States Armed Forces.
The United States Atomic Energy Commission, commonly known as the AEC, was an agency of the United States government established after World War II by U.S. Congress to foster and control the peacetime development of atomic science and technology.
A United States Department of Defense aerospace vehicle designation is determined by a detailed protocol which identifies all aircraft, helicopters, rockets, missiles, spacecraft, and other aerial vehicles in military use by the United States Armed Forces.
An unmanned combat aerial vehicle (UCAV), also known as a combat drone or simply a drone, is an unmanned aerial vehicle (UAV) that usually carries aircraft ordnance such as missiles and is used for drone strikes.
A vertical and/or short take-off and landing (V/STOL) aircraft is an airplane able to take-off or land vertically or on short runways.
A variable-sweep wing, colloquially known as a "swing wing", is an airplane wing, or set of wings, that may be swept back and then returned to its original position during flight.
A vertical take-off and landing (VTOL) aircraft is one that can hover, take off, and land vertically.
Initiated in 2003, X-41 is the designation for a still-classified U.S. military spaceplane.
X-42 is the designation of a still-classified U.S. military space project.