Takeoff and landing
Encyclopedia
Vehicles that can fly
Flight
Flight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....

 can have different ways to takeoff and land. Conventional aircraft accelerate along the ground until sufficient lift is generated for takeoff
Takeoff
Takeoff is the phase of flight in which an aerospace vehicle goes from the ground to flying in the air.For horizontal takeoff aircraft this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft , no...

, and reverse the process to land
Landing
thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...

. Some aircraft can takeoff at low speed, this a short takeoff. Some aircraft such as helicopters and Harrier jump jets can takeoff and land vertically. Rockets also usually takeoff vertically, but some designs can land horizontally.
Takeoff


Takeoff is the phase of flight
Flight
Flight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....

 in which an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 goes through a transition from moving along the ground (taxiing
Taxiing
Taxiing refers to the movement of an aircraft on the ground, under its own power, in contrast to towing or push-back where the aircraft is moved by a tug...

) to flying in the air, usually starting on a runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...

. For balloons
Balloon (aircraft)
A balloon is a type of aircraft that remains aloft due to its buoyancy. A balloon travels by moving with the wind. It is distinct from an airship, which is a buoyant aircraft that can be propelled through the air in a controlled manner....

, helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s and some specialized fixed-wing aircraft (VTOL
VTOL
A vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...

 aircraft such as the Harrier), no runway is needed. Takeoff is the opposite of landing
Landing
thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...

.


Landing


Landing is the last part of a flight
Flight
Flight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....

, where a flying animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

, aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

, or spacecraft
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

 returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing" and "touchdown" as well. A normal aircraft flight would include several parts of flight including taxi
Taxiing
Taxiing refers to the movement of an aircraft on the ground, under its own power, in contrast to towing or push-back where the aircraft is moved by a tug...

, takeoff
Takeoff
Takeoff is the phase of flight in which an aerospace vehicle goes from the ground to flying in the air.For horizontal takeoff aircraft this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft , no...

, climb
Climb
thumb|right|An [[Embraer ERJ 145]] climbingIn aviation, the term climb refers both to the actual operation of increasing the altitude of an aircraft and to the logical phase of a typical flight following take-off and preceding the cruise, during which an increase in altitude to a predetermined...

, cruise
Cruise (flight)
Cruise is the level portion of aircraft travel where flight is most fuel efficient. It occurs between ascent and descent phases and is usually the majority of a journey. Technically, cruising consists of heading changes only at a constant airspeed and altitude...

, descent
Descent (aircraft)
A descent during air travel is any portion where an aircraft decreases altitude, and is the opposite of an ascent or climb. Descents are an essential component of an approach to landing...

 and landing.

Short takeoff and landing (STOL)

STOL is an acronym for short take-off and landing, a term used to describe aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 with very short runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...

 requirements.

Vertical/Short takeoff landing (V/STOL)

Vertical and/or short take-off and landing (V/STOL) is a term used to describe aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 that are able to take-off or land vertically or on short runways. Vertical takeoff and landing (VTOL) describes craft which do not require runways at all. Generally, a V/STOL aircraft needs to be able to hover; helicopters are not typically considered under the V/STOL classification.

A rolling takeoff, sometimes with a ramp (ski-jump), reduces the amount of thrust required to lift an aircraft from the ground (compared with vertical takeoff), and hence increases the payload and range that can be achieved for a given thrust. For instance, the Harrier is incapable of taking off vertically with a full weapons and fuel load. Hence V/STOL aircraft generally use a runway if it is available. I.e. Short Take Off and Vertical Landing (STOVL
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

) or Conventional Take-off and Landing (CTOL
CTOL
CTOL is an acronym for conventional take-off and landing, and is the process whereby conventional aircraft take off and land, involving the use of runways. The aircraft will taxi along the runway until its rotation speed is reached, then climb into the air...

) operation is preferred to VTOL
VTOL
A vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...

 operation.

V/STOL was developed to allow fast jets to be operated from clearings in forests, from very short runways, and from small aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

s that would previously only have been able to carry helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s.

The main advantage of V/STOL aircraft is closer basing to the enemy, which reduces response time and tanker support requirements. In the case of the Falklands War
Falklands War
The Falklands War , also called the Falklands Conflict or Falklands Crisis, was fought in 1982 between Argentina and the United Kingdom over the disputed Falkland Islands and South Georgia and the South Sandwich Islands...

, it also permitted high performance fighter air cover and ground attack without a large aircraft carrier equipped with a catapult.

The latest V/STOL aircraft is the F-35B, which is expected to enter service in 2016.

Catapult assist and arrested recovery (CATOBAR)


Catapult Assisted Take Off But Arrested Recovery (CATOBAR) is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

. Under this technique, aircraft launch using a catapult
Aircraft catapult
An aircraft catapult is a device used to launch aircraft from ships—in particular aircraft carriers—as a form of assisted take off. It consists of a track built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft, or in...

 assisted take off
Assisted take off
Assisted take off is any system for helping aircraft into the air . The reason it might be needed is due to the aircraft's weight exceeding the normal maximum take off weight, insufficient power, or the available runway length may be insufficient, or a combination of all three factors...

 and land on the ship (the recovery phase) using arrestor wires.

Although this system is more costly than alternative methods, it provides greater flexibility in carrier operations, since it allows the vessel to support conventional aircraft. Alternate methods of launch and recovery can only use aircraft with STOVL
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

 or STOBAR
STOBAR
STOBAR is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier, combining elements of both STOVL and CATOBAR .Aircraft launch under their own power using a ski-jump to assist take-off STOBAR (Short Take Off But Arrested Recovery) is a system used for the...

 capability.

Short Take Off But Arrested Recovery (STOBAR)

STOBAR (Short Take Off But Arrested Recovery) is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

, combining elements of both STOVL
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

 (Short Take Off and Vertical Landing.) and CATOBAR
CATOBAR
CATOBAR is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier...

 (Catapult Assisted Take Off But Arrested Recovery).

Spacecraft

Horizontal takeoff, horizontal landing (HTHL) — is the mode of operation for the first private commercial spaceplane, the two-stage-to-space Scaled Composites Tier One from the Ansari X-Prize SpaceShipOne/WhiteKnightOne combination. It is also used for the upcoming Tier 1b
Tier 1b
Tier 1b is Burt Rutan's nickname for the suborbital tourist human spaceflight platform in development at Scaled Composites with Mojave Aerospace Ventures by The Spaceship Company for Virgin Galactic...

 SpaceShipTwo/WhiteKnightTwo combination. A prominent example of its use was the North American X-15
North American X-15
The North American X-15 rocket-powered aircraft/spaceplane was part of the X-series of experimental aircraft, initiated with the Bell X-1, that were made for the USAAF/USAF, NACA/NASA, and the USN. The X-15 set speed and altitude records in the early 1960s, reaching the edge of outer space and...

 program. In these examples the space craft are carried to altitude on a "mother ship" before launch.
The failed proposals for NASA Space Shuttle replacements, Rockwell X-30
Rockwell X-30
-See also:-References: 2. -External links:*...

 NASP used this mode of operation but were conceived as single stage to orbit.

The Lynx rocketplane
Lynx rocketplane
The Lynx rocketplane is a suborbital horizontal-takeoff, horizontal-landing ,rocket-powered spaceplane being developed by the California-based company XCOR to compete in the emerging suborbital space flight market. The Lynx is projected to carry one pilot, a ticketed passenger, and/or a payload or...

 is a suborbital HTHL spaceplane that is slated to begin atmospheric flight testing in late 2011.
Reaction Engines Skylon, a design descendant of the 1980s British HOTOL
HOTOL
HOTOL, for Horizontal Take-Off and Landing, was a British air-breathing space shuttle effort by Rolls Royce and British Aerospace.Designed as a single-stage-to-orbit reusable winged launch vehicle, it was to be fitted with a unique air-breathing engine, the RB545 called the Swallow, to be...

 ("Horizontal Take-Off and Landing") design project, is an HTHL spaceplane
Spaceplane
A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...

 currently under development in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

.

Both the Lynx rocketplane and SpaceShipTwo have been proffered to NASA to carry suborbital research payloads in response to NASA's suborbital reusable launch vehicle (sRLV) solicitation under the NASA Flight Operations Program.

Another example is the 1960s Northrop HL-10
Northrop HL-10
The Northrop HL-10 was one of five heavyweight lifting body designs flown at NASA's Flight Research Center , Edwards, California, from July 1966 to November 1975 to study and validate the concept of safely maneuvering and landing a low lift-over-drag vehicle designed for reentry from space...

 atmospheric test aircraft where the HL stands for "Horizontal Lander".

Vertical takeoff and landing

Different terms are used for takeoff and landing depending on the source of thrust used. VTVL uses rockets, whereas VTOL uses air, propelled via some kind of rotor system.

Aircraft (VTOL)

VTOL is an acronym for vertical take-off and landing aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

. This classification includes fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

 that can hover, take off and land vertically as well as helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s and other aircraft with powered rotors, such as tiltrotor
Tiltrotor
A tiltrotor is an aircraft which uses a pair or more of powered rotors mounted on rotating shafts or nacelles at the end of a fixed wing for lift and propulsion, and combines the vertical lift capability of a helicopter with the speed and range of a conventional fixed-wing aircraft...

s. The terminology for spacecraft and rockets is VTVL
VTVL
Vertical takeoff, vertical landing is a form of takeoff and landing using rockets . Multiple VTVL craft have flown. , at least five VTVL rocket vehicles are currently under development at four different aerospace companies...

(vertical takeoff with vertical landing). Some VTOL aircraft can operate in other modes as well, such as CTOL
CTOL
CTOL is an acronym for conventional take-off and landing, and is the process whereby conventional aircraft take off and land, involving the use of runways. The aircraft will taxi along the runway until its rotation speed is reached, then climb into the air...

 (conventional take-off and landing), STOL
STOL
STOL is an acronym for short take-off and landing, a term used to describe aircraft with very short runway requirements.-Definitions:There is no one accepted definition of STOL and many different definitions have been used by different authorities and nations at various times and for a myriad of...

 (short take-off and landing), and/or STOVL
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

 (short take-off and vertical landing). Others, such as some helicopters, can only operate by VTOL, due to the aircraft lacking landing gear
Landing Gear
Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...

 that can handle horizontal motion. VTOL is a subset of V/STOL
V/STOL
Vertical and/or short take-off and landing is a term used to describe aircraft that are able to take-off or land vertically or on short runways. Vertical takeoff and landing describes craft which do not require runways at all...

 (vertical and/or short take-off and landing).

Besides the ubiquitous helicopter, there are currently two types of VTOL aircraft in military service: craft using a tiltrotor
Tiltrotor
A tiltrotor is an aircraft which uses a pair or more of powered rotors mounted on rotating shafts or nacelles at the end of a fixed wing for lift and propulsion, and combines the vertical lift capability of a helicopter with the speed and range of a conventional fixed-wing aircraft...

, such as the Bell
Bell Helicopter Textron
Bell Helicopter is an American rotorcraft manufacturer headquartered in Hurst, Texas, near Fort Worth. A division of Textron, Bell manufactures military helicopter and tiltrotor products in and around Fort Worth, as well as in Amarillo, Texas, and commercial rotorcraft products in Mirabel, Quebec,...

 Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

 V-22 Osprey
V-22 Osprey
The Bell Boeing V-22 Osprey is an American multi-mission, military, tiltrotor aircraft with both a vertical takeoff and landing , and short takeoff and landing capability...

, and aircraft using directed jet thrust such as the Harrier family
Harrier Jump Jet
The Harrier, informally referred to as the Jump Jet, is a family of British-designed military jet aircraft capable of vertical/short takeoff and landing operations...

.

Rocket (VTVL)

Vertical takeoff, vertical landing (VTVL) is a form of takeoff and landing
Takeoff and landing
Vehicles that can fly can have different ways to takeoff and land. Conventional aircraft accelerate along the ground until sufficient lift is generated for takeoff, and reverse the process to land. Some aircraft can takeoff at low speed, this a short takeoff. Some aircraft such as helicopters and...

 often proposed for reusable spacecraft. Multiple VTVL rocket craft have flown.

Aircraft (VTOHL)

In aviation the term VTOHL
VTOHL
Vertical take-off and horizontal landing is an aircraft that can lift off vertically but land in the traditional manner.While many VTOL aircraft can operate in this fashion, some planes must land normally after taking off vertically due to a vertical landing either being impossible or impractical...

 ("Vertical Take Off and Horizontal Landing") as well as several VTOHL aviation-specific subtypes: VTOCL, VTOSL, VTOBAR exist.

Zero length launch system

The zero length launch system or zero length take-off system (ZLL, ZLTO, ZEL, ZELL) was a system whereby jet
Jet aircraft
A jet aircraft is an aircraft propelled by jet engines. Jet aircraft generally fly much faster than propeller-powered aircraft and at higher altitudes – as high as . At these altitudes, jet engines achieve maximum efficiency over long distances. The engines in propeller-powered aircraft...

 fighters
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...

 and attack aircraft were intended to be placed upon rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s attached to mobile launch platforms. Most zero length launch experiments took place in the 1950s, during the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

.

Spacecraft (VTHL)

VTHLvertical takeoff, horizontal landing—is the mode of operation for all current and formerly operational orbital spaceplane
Spaceplane
A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...

s, such as the Boeing X-37
Boeing X-37
The Boeing X-37 is an American unmanned vertical-takeoff, horizontal-landing spaceplane. The X-37 is operated by the United States Air Force for orbital spaceflight missions intended to demonstrate reusable space technologies...

, the NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

, the 1988 Soviet Buran space shuttle, as well as the circa-1960 USAF Boeing X-20 Dyna-Soar project. For launch vehicles an advantage of VTHL over HTHL is that the wing can be smaller, since it only has to carry the landing weight of the vehicle, rather than the takeoff weight.

There have been several other VTHL proposals that never flew including NASA Space Shuttle proposed replacements Lockheed Martin X-33
Lockheed Martin X-33
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 X-33 was a technology demonstrator for the VentureStar orbital spaceplane, which was planned to be a...

 and VentureStar
VentureStar
VentureStar was a proposed spaceplane design for a single-stage-to-orbit reusable launch system by Lockheed Martin. The program's primary goal as a United States federally funded program was to develop a reusable unmanned spaceplane for launching satellites into orbit at a fraction of the cost of...

. The 1990s NASA concept spaceplane, the HL-20 Personnel Launch System
HL-20 Personnel Launch System
The HL-20 Personnel Launch System was a circa 1990 NASA spaceplane concept for manned orbital missions studied by NASA's Langley Research Center in Hampton, Virginia. HL-20 was envisaged as a lifting body re-entry vehicle based on the Soviet BOR-4 spaceplane design featuring low operational costs,...

 (HL stands for "Horizontal Lander"), was VTHL, as was a circa-2003 derivative of the HL-20, the Orbital Space Plane
Orbital Space Plane
The Orbital Space Plane program was a NASA concept designed to support the International Space Station requirements for crew rescue, crew transport and contingency cargo such as supplies, food and other needed equipment...

 concept.

, two VTHL commercial
Private spaceflight
Private spaceflight is flight above Earth altitude conducted by and paid for by an entity other than a government. In the early decades of the Space Age, the government space agencies of the Soviet Union and United States pioneered space technology augmented by collaboration with affiliated design...

 spaceplanes are currently in various stages of development. Both are successors to the HL-20 design. The Sierra Nevada Corporation
Sierra Nevada Corporation
Sierra Nevada Corporation is an electronic systems provider and systems integrator specializing in microsatellites, energy, telemedicine, nanotechnology, and commercial orbital transportation services. The company contracts with the US military, NASA and private spaceflight companies. The company...

 Dream Chaser follows the HL-20 outer mold line while the Orbital Sciences Corporation
Orbital Sciences Corporation
Orbital Sciences Corporation is an American company which specializes in the manufacturing and launch of satellites. Its Launch Systems Group is heavily involved with missile defense launch systems...

 Prometheus
Prometheus (spacecraft)
Prometheus was a proposed manned vertical-takeoff, horizontal-landing spaceplane concept put forward by Orbital Sciences Corporation in late 2010 as part of the second phase of NASA's Commercial Crew Development program.-Design:...

 is a blended lifting body spaceplane that follows the outer mold line of the circa-2003 Orbital Space Plane, itself a derivative of the HL-20.

The U.S. government-funded, , Reusable Booster System
Reusable Booster System
The Reusable Booster System is a United States Air Force circa-2010 program to develop a new vertical-takeoff, horizontal-landing reusable booster and a new expendable second stage to replace the existing Evolved Expendable Launch Vehicles after 2025.-Program description:Program funding is set...

 program, initiated by the USAF in 2010,
has specified a high-level requirement that the design be VTHL.

HTVL

HTVL or horizontal takeoff and vertical landing is the spaceflight equivalent of aviation HTOVL (and its subtypes CTOVL, STOVL
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

, CATOVL). This mode of operation has not been used, but has been proposed for some systems that use a two-stage to orbit launch system with a plane based first stage, and a capsule return vehicle. One of the few HTVL vehicles is the 1960s concept spacecraft Hyperion SSTO, designed by Philip Bono
Philip Bono
Philip Bono was a Douglas Aircraft Company engineer. He was a pioneer of reusable vertical landing single-stage to orbit launch vehicles....

.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK