This page no longer updated from 31 October 2001. Latest version can be found at www.astronautix.com

astronautix.com Winged

Hotol 2
Hotol 2 - Hotol 2 is launched from the back of an Antonov 225

Credit: British Aerospace. 25,186 bytes. 408 x 257 pixels.


In the beginning, nobody (except Jules Verne) thought anybody would be travelling to space and back in ballistic cannon balls. The only proper way for a space voyager to return to earth was at the controls of a real winged airplane. Peenemuende was already working on the A-4B and A-9/A-10 versions of their missiles before the war ended. Von Braun's concepts of the early 1950's imagined manned gliders with vast swept wingings alighting back at launch base on Earth - and on Mars! The first designs, including the initial space shuttle competitors of the late 1960's, consisted of two stages, both winged, both recovered at base, refueled, and relaunched. By the 1970's some NASA designers claimed a single-stage-to-orbit winged launch vehicle was possible. This was certainly a good alternative the SSTO ballistic designs, which relied on rocket thrust to hover and make a safe landing. As the space shuttle demonstrated, if you can glide you can land without having to rely on any rocket engines functioning. The appealing simplicity of the concept has been offset by the technological risk in developing it. The problem with any single-stage-to-orbit concept is that if the empty weight of the final vehicle has been underestimated it will not be able to deliver any payload to orbit, or even reach orbit. Since weight growth of up to 20% is not unknown in aerospace projects, this is a very real threat which has made both NASA and private investors reluctant to invest the billions of dollars it would take to develop a full-scale flight vehicle. Nonetheless Lockheed was selected in 1996 to develop the X-33 technology demonstrator for just such a vehicle. At last report it was suffering weight growth problems...


Launch Vehicle: EXTV.

This was to a reusable winged rocket-powered atmospheric reentry demonstrator capable of reaching speeds of Mach 4 to 10 in the atmosphere. The aim was for ESA to build up experience in reuse operations and high-speed atmospheric flight in the 2003-2007 period. The demonstrator would weigh two tonnes and have a range of 1500 kilometers. It would be able to land on a conventional runway. Dassault and Aerospatiale Matra were to merge their VEHRA and ARES projects to produce a single design. Ares estimated cost was 550 million dollars.


Launch Vehicle: Themis.

Themis was a planned ESA booster stage demonstrator, to validate integrated propellant tank technology necessary for a reusable Ariane 5 successor. The demonstrator engine would be derived from the Vulcain of the Ariane 5. Estimated cost was up to 2.5 billion dollars. THEMIS would carry 33 tonnes of propellant, enough to reach Mach 11. Expendable boosters might permit orbital flight.


Launch Vehicle: Winged Titan.

Launch Vehicle: V-1. First significant cruise missile. German engineer, Paul Schmidt, working from design of Lorin tube, developed and patented a ramjet engine later modified and used in the V-1 Flying Bomb.

Launch Vehicle: Saenger. Saenger-Bredt antipodal bomber - sled launched, boosted to suborbital velocity, 'skips' off upper atmosphere to deliver bombload on target, recovery back at launch site. Fascinated Stalin, led to US Dynasoar project.

Launch Vehicle: Keldysh Bomber.

Among the advanced designs seized by Soviet forces as they overran Germany was the Saenger-Bredt Antipodal Bomber. This manned spaceplane particularly fascinated Stalin, to the extent that he instructed the NKVD to attempt to kidnap Saenger from his post-war exile in Paris. This did not come to past, but in the immediate post-war period development of a Soviet version of this project was given the highest priority.

On 29 November 1946 the NII-1 NKAP research institute was formed with Mstislav Vsevolodovich Keldysh as its head to investigate and develop the Saenger-Bredt design. Through 1947 studies revealed that the high fuel consumption of Saenger's pure rocket design made the concept unworkable in the near term. Using engines thought to be available in the near term, 95% of the winged vehicle's lift-off mass would have to be propellant. However use of ramjets during the acceleration process would allow the spacecraft to have a more reasonable 22% dead weight fraction and still achieve the 5 km/sec cut-off velocity required for the 12,000 km intercontinental range.

It was clear from the preliminary study that an immense amount of work needed to be done before even a draft project of a feasible design could be prepared. However this would be accomplished by the mid-1950's. The Keldysh design would lead through the EKR and MKR to the Buran and Burya Mach 3 intercontinental ramjet missiles.


Launch Vehicle: BIS 3 Stage. The British Interplanetary Society (BIS) reusable booster concept of 1950 was a 3 stage, rocket, similar to Von Braun concepts of the time. The third stage was a winged vehicle which would use the skip-glide re-entry technique conceived by Saenger.

Launch Vehicle: RS.

The Tsybin RS was originally a high-speed ground-launched manned aircraft. The March 1954 draft project specified a twin ramjet vehicle that would cruise at 3,000 km/hr at 30 km altitude, over a 14,400 km range, with a takeoff mass of only 22 tonnes. To achieve this performance would require that 75% of the takeoff mass would be structure, and 3% payload, leaving only 22% for the vehicle. This was not achievable, and the final design had an empty weight 43% of the takeoff weight, cutting the range in half. By August 1956 the design had been modified to the more modest RSR configuration, which was air launched, cruised at 2800 km/hour at 26,700 m with a 1700 km radius of action. A subsonic aerodynamic test vehicle, the NM-1 was built and first flown on 7 April 1959 by test p[ilot Amert-Khan Sultan. Construction of prototypes was started the same year, but then stopped in the spring of 1961, with three airframes nearly finished. Tsybin went to work for Korolev at OKB-1.


Launch Vehicle: Navaho/X-15.

North American proposed several methods of taking the X-15 spaceplane to higher velocities and altitudes. One of these involved the use of one to three Navaho booster rockets, which could even place the X-15 into orbit. This incremental approach to manned spaceflight was not pursued - the Mercury and X-20 Dynasoar programs were favored instead.


Launch Vehicle: X-15A. Manned hypersonic research rocket aircraft.

Launch Vehicle: X-15A-2. Manned hypersonic research rocket aircraft. Stretched rebuild of crashed X-15A, with drop tanks. Reached Mach 6.7 and 108 km altitude.

Launch Vehicle: Martin Astrorocket. Early two-stage-to-orbit shuttle study, using storable propellants, Dynasoar-configuration delta wing orbiter and booster.

Launch Vehicle: RAE TSTO. The Royal Aircraft Establishment Two Stage To Orbit (TSTO) Concept of the 1960's consisted of a hypersonic air-breathing first stage and rocket powered second stage.

Launch Vehicle: Saenger I.

Launch Vehicle: Mustard.

A British Aircraft Corporation study of 1964-1965 for winged reuseable space shuttle using the 'triamese' concept - reduced costs by use of two boosters nearly identical to the orbiter vehicle. The components were lifting bodies with a configuration similar to the US HL-10 vehicle. MUSTARD was an abbreviation for Multi-Unit Space Transport And Recovery Device. The orbiter would be capable of reaching orbit with nearly a full fuel load, since propellant from the two boosters could be pumped into the orbiter prior to separation. This would have allowed the orbiter to reach the moon! Various configurations were examined such as (back-to-back, triangular back-to-back, 2 x back-to back and 1 inline). Developed by a team led by Tom Smith, the MUSTARD vehicles would have been capable of being flown back via remote control or by a pilot.


Launch Vehicle: RAE Orbital Fighter.

The Royal Aircraft Establishment Orbital Fighter proposal of the 1960's envisioned a two stage vehicle. A ramjet powered first stage would release a second stage orbiter similar to, but smaller than the U.S. X-20 Dyna-Soar. The spaceplane would utilise a gliding re-entry to return to earth.


Launch Vehicle: Spiral 50-50.

Mikoyan GKAT OKB-155 began work in 1960 on the Spiral combination aerospace system. In 1965 the advanced project was approved, laying out an ambitious work plan leading to operation of a regular earth-orbit-earth reusable transportation system by the mid-1970's. Go-ahead to actually proceed with development of the manned orbital vehicle was given on 26 June 1966 and Lozino-Lozinsky was selected as project manager.

The Spiral system consisted of three main components:

  • GSR reusable hypersonic air-breathing launch aircraft
  • RB expendable two stage rocket
  • OS orbital spaceplane

    The project plan for Spiral was as follows:

    • 1967 - Subsonic test flight of OS (article 105-11)
    • 1968 - Hypersonic test flight of OS (article 105-12)
    • 1970 - Unpiloted orbital flight of OS (Soyuz-launched - article 105-13)
    • 1970 - Construction of GSR to begin
    • 1972 - First rollout of LH2-propelled experimental GSR
    • 1977 - First piloted orbital flight of complete system

    Interest in the project at higher levels of the Soviet hierarchy was difficult to maintain, due to the massive funding requirements, technical difficulties, and multi-year development program which could not promise quick results. Underfunded from the beginning, the project was finally reoriented to a simple test of the analogue systems without using these as the basis for a flight system. This was now designated EPOS (Experimental Piloted Orbital Aircraft) and would be flown by Soviet Air Force test pilots rather than cosmonauts. In February 1976, with the beginning of work on Buran, the project was effectively ended except for the test of the subsonic 105-11 article already built. The 105-11 incorporated the airframe and some of the systems of the planned orbital version.

Launch Vehicle: Albatros.

Unique Russian space shuttle design of 1974. Hydrofoil-launched, winged recoverable first and second stages. Hydrofoil would have been propelled to launch speed by the launch vehicles rocket engines, using a 200 tonne fuel store in the hydrofoil. Advantages: launch from the Caspian Sea into a variety of orbital inclinations, variations in launch track possible to meet range safety requirements. Proposal of Alexeyev/Sukhoi OKBs.


Launch Vehicle: VTOHL 45t. Vertical Takeoff Horizontal Landing (winged).

Launch Vehicle: VTOHL 9t. Vertical Takeoff Horizontal Landing (winged).

Launch Vehicle: System 49.

The Spiral project was not cancelled with the decision to proceed with the large Buran spaceplane. Instead flight test of the orbiter continued but the launcher design was rethought. The ambitious Mach 4 air-breathing first stage was abandoned in favour of launch from an existing subsonic heavy transport. The first iteration of the new design was undertaken in 1977-1978 as the AKS project at the Scientific Research Institute 'Rosa'. This used the second rocket stage and orbiter stage of Spiral, designated RUOS in this study. This design was the starting point that would evolve through the System 49 and Bizan designs, finally resulting in the MAKS of 1988.

The System 49 design had the same arrangement as Spiral. The rocket stages and the Spiral orbiter were mounted on the back of an An-124 subsonic transport. By the time of the design, the Spiral configuration had been proven in the MiG-105-11 and BOR-4. The combined orbiter and rocket stages, weight 200 tonnes, would be launched at an altitude of 10 km and a speed of Mach 0.7. Effective velocity gain compared to a vertical launch from the ground was 270 m/s.

The first stage would use Lox/Kerosene propellants and 2 NK-43 / 11D112 engines. The second stage was equipped with a single RD-57M / 11D57M engine burning Lox/LH2 propellants. Two rocket stage layouts were studied: a traditional tandem scheme, and a 'piston' / 'wrap around' concept, where the toroidal propellant tanks of the first stage surrounded the second stage.

The orbiter would have a mass of 13 tonnes, and could deliver a payload of 4 tonnes to orbit in a 27 cubic metre payload compartment (dimensions 6.0 m long x 2.8 m x 1.6 m). Orbits from 120 to 1000 km altitude, and 45 to 94 degrees inclination could be achieved thanks to the flexibility of airborne launch. The orbiter was flown by a single pilot, had sufficient consumables for 5 to 12 hours of on-orbit operations, and was designed for 100 reuses. It could achieve up to 1000 km cross-range during re-entry and landed at a speed of 300 to 310 km/hr.

The design was found to be feasible but to have little growth potential. Greater payload could only be achieved by the completely different 49M using a new super-heavy carrier aircraft and orbiter. Therefore it was succeeded in the design studies by the 'Bizan' concept.


Launch Vehicle: System 49-M.

The 49M was an application of the system 49 design concept, but with a larger carrier aircraft. The system would have a 770 tonne gross takeoff mass. The orbiter/rocket stage combination weighted 370 tonnes, with the orbiter mass being 28 tonnes in orbit, including a 9 tonne payload in a 8.0 m x 3.3 m diameter payload bay. The tripropellant single rocket stage was equipped 1 x NK-43 / 11D112 engine burning Lox/Kerosene and 2 x RD-57 / 11D57 engines burning Lox/LH2. The orbiter could have one or two crew, and was designed for 100 reuses. Development costs for the new heavy lift aircraft and larger orbiter would be too high, and the design was abandoned in favour of the Bizan concept.


Launch Vehicle: Bizan.

Bizan was the 1982 Soviet air-launched spaceplane design iteration between the '49' and 'MAKS' concepts. Like the '49', it was air-launched from atop an An-124 transport. Unlike the '49', it was a single-stage-to-orbit tripropellant concept. The rocket stage was equipped with Lox/Kerosene engines while the orbiter had reusable Lox/LH2 engines that drew propellant from the rocket stage. The advantage with the single stage was that the stage would land in the ocean across the world from the launch point. In the two-stage System 49, the first stage would crash into a drop zone 2000 km from the launching aircraft.

The rocket stage was equipped with a single NK-43A / 11D112A engine. The 15 tonne orbiter had two RD-57M / 11D57M engines. The orbiter had a 1000 km cross range and a landing speed of 300 km/hr. One crewmember could stay aloft for mission durations of up to 24 hours. The orbiter was designed for 200 reuses and had a 6.0 m x 2.8 m payload bay. As in the '49' concept, orbits of from 120 to 1000 km altitude and 45 to 94 degrees inclination could be attained.


Launch Vehicle: Bizan-T. Air launched from catamaran heavy-life aircraft, predecessor of later Gerakl / Molniya-1000 design. 900 tonnes takeoff mass. Release conditions: Suspended load, Mach 0.7 at 8 to 9 km altitude. Effective velocity gain compared to vertical launch 270 m/s.

Launch Vehicle: HOTOL.

Single-stage-to-orbit winged launch vehicle (horizontal takeoff/horizontal landing) using a unique engine design. The RB545 air / liquid hydrogen / liquid oxygen rocket engine was to be developed by Rolls-Royce. HOTOL development was begun in 1982 by a Rolls-Royce / British Aerospace team led by John Scott and Dr Bob Parkinson. The project was reasonably well advanced (engine detailed design and mockup) by the time the British government withdrew further funding in the mid-1980's. HOTOL would have taken off horizontally from a runway, from a purpose made, rocket propelled trolley. It would transition to pure rocket propulsion at Mach 5.0 - Mach 6.0. and ascend to orbit. A moderate re-entry profile would decrease the thermal loading constraints. HOTOL would return via a glide landing, to a landing on gear on a conventional runway.

The HOTOL airframe was derived from conventional vertical takeoff rockets with the engines mounted at the rear of a blunt based fuselage. Since such a vehicle’s empty centre of gravity is dominated by the engine location, the wings and the tank for the dense liquid oxygen also had to be at the rear. The payload bay and hydrogen tankage were placed in a projecting forebody. The resulting configuration suffered from a severe centre of pressure / centre of gravity mismatch during the air breathing ascent. The centre of pressure shifted 10 m forward, due to the wide Mach range, the large fuselage cross section to wing area ratio, and the long overhang of the forward fuselage. Various alterations were made to the design to handle these problems, all of which eroded the payload. Conventional landing gear were replaced by a specially designed takeoff trolley in order to improve the marginal payload fraction. The final design had serious operational disadvantages and a small payload. The only way the designers could continue to claim to put a reasonable payload into orbit was by specifying untried and speculative structural materials.


Launch Vehicle: LART. MBB/ERNO airbreathing horizontal takeoff / horizontal landing single stage to orbit proposal from the mid-1980s. Largely similar to the BAe HOTOL.

Launch Vehicle: Saenger II.

Proposed two stage to orbit vehicle. Air-breathing hypersonic first stage and delta wing second stage. The German Hypersonics Programme and its Saenger II reference vehicle received most of the domestic funding for spaceplane development in the late 1980s and early 1990s. Saenger II comprised a large hypersonic booster aircraft capable of Mach 4 cruise plus a small rocket-powered upper stage (HORUS) that could deliver people and cargo to low Earth orbit. The booster aircraft (to be powered by turboramjets) was designed for maximum commonality with a supersonic passenger transport (with. a cruise range of 11,000km). Development would have been very costly and the programme was cancelled in 1994.


Launch Vehicle: Mikoyan 301.

The 301 was designed as a military bomber, with a Mach 4 / 4,250 km/hr cruise capability at 25,000 to 27,000 m altitude. It was equipped with two turboramjets, had a gross takeoff mass of 80 tonnes, of which half was fuel. It may be related to the first stage of the MIGAKS two-stage vehicle.


Launch Vehicle: Tu-2000.

In reaction to US X-30 project, government decrees of 27 January and 19 July 1986 ordered development of a Soviet equivalent. The Ministry of Defence issued technical specifications on 1 September for an MVKS, a single-stage reusable aerospaceplane system. The MKVS was to provide effective and economic delivery to near-earth orbit; develop the technology for effective transatmospheric flight; provide super high-speed intercontinental transport, and fulfil military objectives in and from space. It is known that the Tupolev, Yakovlev, and Energia design bureaux submitted designs.

Tupolev seems to have received the development go-ahead. The Tu-2000A was to be an experimental design to test the many advanced technologies required. It would have been 55 to 60 m long, have a 14 m wingspan, and a takeoff mass of 70 to 90 tonnes. It would have only been capable of Mach 6. Before work was stopped in 1992, some development work was completed: a wing torque box of nickel alloy had been built, as well as fuselage elements, cryogenic fuel tanks, and composite fuel lines. The Tu-2000A would have used a variable cycle turboramjet engine using methane or hydrogen fuel.

The Tu-2000A was to have been followed by two production designs, as Tupolev felt no single design could meet all of the military requirements. The Tu-2000B would have been a 10,000 km range bomber with a crew of two. 350 tonnes at takeoff, 200 tonnes empty, it would have been 100 m long, with a wing of 40.7 m span and 1250 square metres area. Six liquid hydrogen powered engines would take the bomber to Mach 6 cruise speed at 30,000 m altitude.

The Tu-2000 space launcher would have weighted 260 tonnes at lift-off and be capable of Mach 25 (orbital velocity). An 8 to 10 tonne payload would have been delivered to a 200 km orbit. As with the X-30, airbreathing flight to orbit seemed questionable. The 8 turboramjets would have to be supplemented by a scramjet or a rocket engine in order to achieve orbit.


Launch Vehicle: VKS.

In reaction to US X-30 project, government decrees of 27 January and 19 July 1986 ordered development of a Soviet equivalent. The Ministry of Defence issued technical specifications on 1 September for an MVKS, a single-stage reusable aerospaceplane system. The MKVS was to provide effective and economic delivery to near-earth orbit; develop the technology for effective transatmospheric flight; provide super high-speed intercontinental transport, and fulfil military objectives in and from space. It is known that the Tupolev, Yakovlev, and Energia design bureaux submitted designs.

At NPO Energia Tsybin was appointed the Chief Designer for the project. The Energia VKS was designed as a hypersonic rocketplane with multi-regime engines. These engines were turbo-ramjet with in-line rocket chambers. The VKS was sketched out as having a 700 tonne takeoff mass, of which 140 tonnes was structure. A 25 tonne payload could be delivered to a 200 km / 51 degree orbit. Length would have been 71 m, wingspan 42 m, and height 10 m to the top of the fuselage.

Work was abandoned as the Soviet Union broke up and the Tu-2000 seemed the preferred solution.


Launch Vehicle: Yakovlev MVKS.

In reaction to US X-30 project, government decrees of 27 January and 19 July 1986 ordered development of a Soviet equivalent. The Ministry of Defence issued technical specifications on 1 September for an MVKS, a single-stage reusable aerospaceplane system. The MKVS was to provide effective and economic delivery to near-earth orbit; develop the technology for effective transatmospheric flight; provide super high-speed intercontinental transport, and fulfil military objectives in and from space. It is known that the Tupolev, Yakovlev, and Energia design bureaux submitted designs. No details of the Yakovlev design have become available to date.


Launch Vehicle: EARL I.

Vertical takoff/horizontal landing two stage launch vehicle study from the 1980s. A larger Earl 14 configuration was studied, but the study centered on the Earl 5 / 18 / 7 configurations. The second stage was mounted on top of the booster. Earl 5 and 7 had winged second stages, with payloads to low earth orbit of 5380 kg to 7180 kg. Earl 14 featured an expendable upper stage which increased payload to 18,000 kg.


Launch Vehicle: STS-2000 SSTO. Single stage to orbit ramjet/rocket mix power horizontal takeoff / horizontal landing study of the 1980's.

Launch Vehicle: STS-2000 TSTO. Two stage to orbit horizontal takeoff / horizontal landing variant of STS-2000. Ramjet/rocket mixed power first stage. Mach 6 separation of rocket-powered second stage. French study of the 1980's.

Launch Vehicle: Ariane 5 FLS. Partially reusable concept using Ariane 5 core with twin reusable flyback boosters.

Launch Vehicle: MAKS.

The MAKS spaceplane was the ultimate development of the air-launched spaceplane studies conducted by NPO Molniya. The draft project for MAKS was completed in 1988 and consisted of 220 volumes, generated by NPO Molniya and 70 sub-contractors and government institutes. Development of MAKS was authorised but cancelled in 1991. At the time of the cancellation, mock-ups of both the MAKS orbiter and the external tank had been finished. A 9,000 kgf experimental engine with 19 injectors was tested. There were 50 test burns proving the separate modes and a smooth switch between them. Since it was expected that MAKS could reduce the cost of transport to earth orbit by a factor of ten, it was hoped in the 1990's that development funding could be found. However this did not materialise. MAKS was to have flown by 1998.


Launch Vehicle: MAKS-M.

Fully reusable unpiloted verion of MAKS, similar to Interim HOTOL. Air launched from An-225. MAKS was found to have superior payload, lower non-recurring cost and technical risk. MAKS-M would require new materials. Release conditions: Piggy-back, 275,000 kg, 38.0 m length x 24.0 m wingspan, 900 kph at 9,500 m altitude. Effective velocity gain compared to vertical launch 270 m/s. Payload bay 7.0 m long x 4.6 m diameter.


Launch Vehicle: MAKS-T.

All cargo version of MAKS. Air-launched heavy-lift launcher would use an expendable second stage with a payload container. Release conditions: Piggy-back, 275,000 kg, 38.0 m length x 24.0 m wingspan, 900 kph at 9,500 m altitude. Effective velocity gain compared to vertical launch 270 m/s. Payload bay 13.0 m long x 5.0 m diameter.


Launch Vehicle: VKS-D. Air launched from An-225. Release conditions: Piggy-back, 275,000 kg, 38.0 m length x 24.0 m wingspan, 900 kph at 9,500 m altitude. Effective velocity gain compared to vertical launch 270 m/s.

Launch Vehicle: VKS-DM. Air launched from Gerakl / NPO Molniya-1000 heavy-lift aircraft, catamaran layout, twin-fuselage triplane. Release conditions: Suspended load, 450,000 kg, 900 kph at 9,500 m altitude. Effective velocity gain compared to vertical launch 270 m/s.

Launch Vehicle: VKS-G.

Air launched from Kholod Mach 5 mother ship. This was a Mikoyan supersonic cargo aircraft, designed from Spiral 50-50 design. Combined-cycle turbo-ramjet engine. Release conditions: Piggy-back, 200,000 kg, Mach 5 at 25 to 30 km altitude. Effective velocity gain compared to vertical launch 1130 m/s. It was concluded that the extensive development would be required for the combination-cycle engines, resulting in an extended development schedule and high technical risk. The more conservative subsonic-launched MAKS was chosen instead.


Launch Vehicle: VKS-O.

Vertical takeoff, ballistic re-entry, single-stage-to-orbit, Lox/Kerosene/LH2 tripropellant rocket engine powered, reusable launch vehicle. 550 tonne and 770 tonne gross lift-off mass versions considered. For the 550 tonne version, dry mass of the launch vehicle would have to be 68,700 kg / 18 percent of the gross, with payload 8,500 kg / 1.5 percent of the growth. Payload would range from 2000 to 10,000 kg depending on the uncertainties in weight growth of the design during development. As in other vertically-launched SSTO designs, this was considered too great a risk, and the air-launched MAKS was selected instead. Velocity loss during ascent estimated at 1665 m/s compared to 1168 m/s for MAKS (payload 3.1% of gross).


Launch Vehicle: VKS-R.

Sled launched, delta winged, single-stage-to-orbit, Lox/LH2 launch vehicle. 290 tonne and 550 tonne versions considered. Sltudied in tradeoff studies leading to MAKS. Release conditions: Piggy-back, 290,000 kg, Mach 0.5, zero altitude. Effective velocity gain compared to vertical launch 100 m/s. The wheeled sled would get the vehicle up to a velocity where the wings could provide lift, allowing lower-thrust engines to be used than in a vertical-takeoff design. This saved weight, but velocity losses during lifting flight to orbit almost cancelled the advantage, resulting in the approach being unattractive in comparison to pure vertical-launch or air-launch designs.


Launch Vehicle: VKS-RTO+ZhRD. Horizontal takeoff, delta winged, single-stage-to-orbit, launch vehicle. Mixed rocket / ramjet propulsion.

Launch Vehicle: VKS-V.

Vertical takeoff, delta winged, single-stage-to-orbit, Lox/Kerosene/LH2 tripropellant rocket engine powered vehicle. 550 tonne gross liftoff mass and 1000 tonne versions studied. Analogous to NASA's Shuttle-2 and RKK Energia's VKS. For the 550 tonne version, dry mass of the launch vehicle would have to be 67,700 kg, with payload 7,500 kg / 1.4 percent of the growth. Payload could therefore be zero depending on the uncertainties in weight growth of the design during development. As in other vertically-launched SSTO designs, this was considered too great a risk, and the air-launched MAKS was selected instead. Velocity loss during ascent estimated at 1619 m/s compared to 1168 m/s for MAKS (payload 3.1% of gross).


Launch Vehicle: VKS-ZhRD+GPVRD. Horizontal takeoff, delta winged, single-stage-to-orbit, launch vehicle. Mixed rocket / scramjet propulsion.

Launch Vehicle: Buran-T. Fully recoverable version of Energia launch vehicle, with four winged boosters and a winged core stage.

Launch Vehicle: Star-H. European recoverable spaceplane with Hermes spaceplane.

Launch Vehicle: Aerospatiale VTVL. Aerospatiale vertical takeoff, vertical landing single stage to orbit study.

Launch Vehicle: Astros.

Under the Future European Space Transportation Investigation Programme (FESTIP) of 1994-1999 French agencies and contractors designed a number of alternative reusable space launchers. This one was a Sled-launched horizontal takeoff / horizontal landing single stage to orbit. Essentially similar to FESTIP FSS-4


Launch Vehicle: DSL HTHL.

Under the Future European Space Transportation Investigation Programme (FESTIP) of 1994-1999 French agencies and contractors designed a number of alternative reusable space launchers. This one was a Horizontal Takeoff / Horizontal Landing Two Stage to Orbit proposal with Mach 3 stage separation. Later evolved into the FESTIP FSS-11,which was merged with FSS-12. Reusable and expendable upper stage options.


Launch Vehicle: EARL II. Later EARL version from 1990. Parallel staging, both stages winged and recoverable. Expendable upper stage for heavy-lift missions.

Launch Vehicle: Interim HOTOL.

Initiated by a British Aerospace team led by Dr Bob Parkinson in 1991, this was a less ambitious, scaled-back version of the original HOTOL. The single-stage to orbit winged launch vehicle using four Russian rocket engines. It was to have been air-launched from a Ukrainian An-225 Mriya (Dream) aircraft. Interim HOTOL would separate from the carrier aircraft at subsonic speeds, and would then pull up for the ascent to orbit. It would return via a gliding re-entry and landing on gear on a conventional runway. Interim HOTOL suffered from the same aerodynamic design challenges as HOTOL and went through many, many design iterations in the quest for a practical design.


Launch Vehicle: Oriflamme. French design for a scramjet-powered horizontal takeoff / horizontal landing, single stage to orbit vehicle.

Launch Vehicle: Radiance. Two stage to orbit horizontal takeoff / horizontal landing vehicle. Booster would be powered by scramjets to Mach 12 separation before second stage separated.

Launch Vehicle: RWDT HTHL.

Under the Future European Space Transportation Investigation Programme (FESTIP) of 1994-1999 French agencies and contractors designed a number of alternative reusable space launchers. This one was a Horizontal Takeoff / Horizontal Landing Two Stage to Orbit proposal with Mach 4 stage separation. Vehicle consisted of an unpowered 'reusable winged drop tank' and 2-engine expendable Ariane-5 upper stage.


Launch Vehicle: Spacebus.

The Bristol Spaceplanes Spacebus was a Two Stage To Orbit (TSTO) Manned Spaceplane, with an airbreathing supersonic / hypersonic, delta winged first stage and a second stage powered by a liquid fuelled rocket engine. It was proposed by David Ashford of Bristol Spaceplanes Ltd. in the 1980`s / 1990's. The 6-crew Concorde-sized Spacecab would serve as a prototype for the larger 50-person Spacebus.


Launch Vehicle: Spacecab.

The Bristol Spaceplanes Spacecab was a Two Stage To Orbit (TSTO) Manned Spaceplane, with an airbreathing supersonic / hypersonic, delta winged first stage and a second stage powered by a liquid fuelled rocket engine. It was proposed by David Ashford of Bristol Spaceplanes Ltd. in the 1980`s / 1990's. The Concorde-sized spacecraft would deliver a payload of 6 persons to low Earth orbit. It would serve as a prototype for the larger 50-person Spacebus.


Launch Vehicle: STAR-H. Mach 6 hypersonic first stage would launch Hermes spaceplane with an expendable second stage.

Launch Vehicle: TARANIS. French study of vertical takeoff / horizontal landing, two stage to orbit launch vehicle with expendable orbiter fuel tanks.

Launch Vehicle: X-30. Air-breathing scramjet single stage to orbit. Second attempt after study of similar proposal in early 1960's. Cancelled due to cost, technical challenges.

Launch Vehicle: Ascender.

The Bristol Spaceplanes Ascender of the 1990`s was a sub-orbital manned spaceplane concept proposed by David Ashford. The Ascender spaceplane would use a small Viper tubojet engine as well as a main liquid fuel rocket engine. The Ascender would act as a technology demonstrator for the orbiter of the orbital Spacecab concept,.


Launch Vehicle: 17K-AM. A small two stage to orbit horizontal takeoff / horizontal landing vehicle proposed for the Russian Air Force in 1993.

Launch Vehicle: ADLER. Ariane-5 derived semi-reusable proposal. Expendable fuel tanks but recoverable propulsion/avionics module.

Launch Vehicle: Ajax. Sled-launched, air-breathing, single stage to orbit, horizontal takeoff / horizontal landing launch vehicle proposed in Russia.

Launch Vehicle: Ariane 5 RRL. Partially reusable concept using Ariane 5 core with flyback booster stages with Russian engines (RD-120 or RD-701).

Launch Vehicle: ASA. Sled-launched airbreathing single stage to orbit horizontal takeoff / horizontal landing launch vehicle proposed in Russia.

Launch Vehicle: Black Colt.

Winged, first stage of a launch vehicle using aerial refueling and existing engines. Takes off from runway; rendezvous with tanker to load oxidizer; then flies to Mach 12/150 nm to release Star 48V second stage and 450 kg payload. In comparison to Black Horse, uses existing engines and a much more achievable mass fraction by only flying to half orbital speed.


Launch Vehicle: Herakles. Launch vehicle design by NPO Molniya / TsAGI that would utilize air launch from a giant cargo aircraft capable of lifting 900 tonne payloads. The single stage to orbit spaceplane would be released at subsonic velocity.

Launch Vehicle: LII Spaceplane. LII (the Gromov Experimental Flight Institute at Zhukoskiy) designed several alternate spaceplane concepts for air-launch from the An-225 transport. These were similar to the various MAKS concepts.

Launch Vehicle: MAKS-D.

NPO Molniya, Antonov, and TsAGI proposed a spaceplane demonstrator project to the European Space Agency in 1993-1994 under the RADEM project. This would be a scaled-back version of the cancelled MAKS spaceplane using existing rocket engines. An unmanned prototype of the MAKS would be fitted out with RD-120 Lox/Kerosene engines. Launched from atop the An-225, the MAKS-D would reach an altitude of 80 to 90 km and a speed of Mach 14 to 15.

The ES experimental spacecraft would have a launch mass of 56 tonnes, including 45 tonnes of propellant. It would fly at hypersonic speed out to a range of 1500 km, then return to an automatic landing at its launching base. Three variants were proposed:

  • Basic variant. Purpose of the flight tests would be to prove MAKS-M / I-HOTOL flight algorithms, materials, and engine reusability. 38.0 m length x 24.0 m wingspan

  • Basic variant modified for scramjet flight tests

  • Orbital vehicle with 2 tonnes payload. For the orbital vehicle the MAKS-D served as the first stage of the booster. It would release the RS rocket stage, equipped with a European HM-7B Lox/LH2 engine. The rocket stage engine would ignite five seconds after release of the aircraft from the An-225 transport and work in tandem with the RD-120 installed on MAKS-D. Following exhaustion of main stage propellants the MAKS would release the rocket stage, which would continue on to orbit. This scheme was analogous to NASA's early X-34 concepts.

Launch Vehicle: MiG-2000.

Sled-launched single stage to orbit vehicle with air-breathing propulsion to Mach 5 (subsonic combustion). The sled would accelerate the launch vehicle to Mach 0.8. Propellants wer slush hydrogen and liquid oxygen. The vehicle would have a 3000 km cross-range on re-entry.


Launch Vehicle: MIGAKS. Turbojet/ramjet-powered two stage to orbit horizontal takeoff / horizontal landing vehicle. Mach 6 stage separation. The orbiter had a 2000 km cross-range capability with landing on airfields with runways of 3500 m length or more.

Launch Vehicle: Black Horse. Winged, single stage to orbit launch vehicle using aerial refueling and lower performance, non-cryogenic propellants. Takes off from runway at 22,000 kg gross weight; rendezvous with tanker to load 66,760 kg oxidizer; then flies to orbit.

Launch Vehicle: Ariane 5 VTVL. Partially reusable concept using Ariane 5 core with vertical takeoff, vertical landing boosters.

Launch Vehicle: Hytex. Following the cancellation of Saenger II, Germany briefly considered a manned X-15/NASP type flight test vehicle (HYTEX) capable of Mach 6 flight. This too was cancelled for cost reasons.

Launch Vehicle: Japanese Space Plane. NAL / Mitsubishi Heavy Industries, Ltd. design for a single stage to orbit spaceplane. Crew of ten, empty mass 110 tonnes. LACE / Scramjet engines, 29 m wingspan.

Launch Vehicle: Skylon.

Launch Vehicle: X-33. NASA-sponsored suborbital unmanned prototype for single stage to orbit winged spacecraft. Lockheed Martin vehicle will use linear aerospike engines, metallic insulation, other features similar to their Starclipper shuttle proposals of 1971.

Launch Vehicle: X-34.

NASA failed to attract industry co-investment to develop an X-34 air-launched, reusable, low-technology, low-cost launch vehicle. So the project was scaled back and NASA contracted with Orbital Sciences to build and fly an unmanned technology demonstrator. Objectives were to demonstrate new, efficient vehicle processing and launch operations and evaluate the performance of advanced reusable launch vehicle technologies. The program was to demonstrate a nominal two-week turnaround between flights, and a surge capability of two flights within 24 hours. The single stage vehicle used NASA’s low cost Fastrac engine for liquid oxygen/kerosene propulsion. The vehicle itself used all-composite primary and secondary structure. Its autonomous flight control system was to make automated approach and landings. Flights were planned to speeds of Mach 8 over an 800 km range. The contract with Orbital Sciences covered construction of three flight vehicles and 26 powered and unpowered flights launched from an L-1011.


Launch Vehicle: X-34A. NASA-sponsored air-dropped unmanned hypersonic winged launch vehicle stage. Plans to use as first reusable stage for two-stage light satellite launcher dropped when commercial backing evaporated after dispute over engine selection.

Launch Vehicle: Norma.

Semi-reusable vertically launched two-stage-to-orbit vehicle. The flight profile featured a reusable flyback booster launched from a modular launch platform, an expendable second stage with a reusable orbiter that would have landed vertically. Development cost estimated at $13 billion.


Launch Vehicle: Orel V2.

In the late 1990's the Russian space industry undertook the Orel programme to evaluate technology for future launch vehicles. The goals included evaluation of possible concepts for a future Russian launcher, reusable launch vehicle key technology research and analysis of "X-vehicle" flight demonstrators for technology validation. One preferred near-term configuration was this semi-reusable vertical takeoff/horizontal landing two stage launch vehicle. It would use a flyback booster, expendable second stage, and a small manned spaceplane. This was preferred to the Orel V3, which was essentially the earlier MMKS/OK-M1 system with a flyback booster, expendable core tank, and small spaceplane with recoverable main engines.


Launch Vehicle: Orel V4. Fully reusable vertical takeoff, horizontal landing two stage to orbit concept. Abandoned in favor of Orel V6.

Launch Vehicle: Orel V5. Vertically launched two stage to orbit concept consisting of horizontal landing booster, vertical landing orbiter. Abandoned in favor of Orel V6.

Launch Vehicle: Orel V6. Fully reusable vertical takeoff / horizontal landing single stage to orbit launch vehicle. The preferred long-term alternative of the Russian Orel launch vehicle study of the 1990's.

Launch Vehicle: Vehra.

Dassault design for an air-launched experimental reusable launch vehicle. It would be launched from Novespace's Airbus 300 zero-G aircraft. The lifting-body design was loosely based on Dassault's work on the NASA-led X-38 Crew Rescue Vehicle program. VEHRA weighed 6.5 t tonnes and carried 19.5 tonnes of kerosene and oxygen propellant. One Russian 400.5 kN-thrust NK-39 engine would power the vehicle, which would be capable of reaching Mach 14. The 11.5 meter long vehicle also contained a small 1.5 x 1.5 x 5 meter payload bay for an expendable upper stage+250 kg satellite. Like THEMIS, VEHRA would explore hypersonic flight and the operational and cost aspects of reusability.


Launch Vehicle: Roton.

Launch Vehicle: FLTP.

The FLTP (Future Launcher Technology Program) was an ESA (European Space Agency) program, with responsibility assigned to CNES (Centre National d'Etudes Spatiales), the same center that developed Diamant and Ariane. The objective of FLTP was to identify and develop technologies necessary for the successor to Ariane 5. The planned configuration was a two-stage fully recoverable winged launch vehicle. The winged booster would deliver the orbiter to a given altitude, the two separate, and the booster flies back to its launch base. The second stage orbiter continues to orbit, delivers its payload and then returns to the original launch site on Earth. Launch and landing were to be from the CSG (Centre Spatial Guyanais) at Kourou. The first flight was planned for 2020. The spacecraft was designated to be unmanned. But its configuration could include human cargo at a later point.

The FLTP program was launched at the interministerial conference of ESA in May 1999, with funding of $ 48 million for 1999 to 2001. This was to be followed by an 18 month period during which a technology demonstration program would be defined for approval at the ESA interministerial council in mid-2001. This demonstration program would run from 2002 to 2007, at which time a decision on Ariane 5's successor could be made. Two flying demonstrators were envisioned for the technology phase:

  • EXTV (European eXperimental Test Vehicle). This was to be a reusable winged rocket-powered atmospheric reentry demonstrator capable of reaching speeds of Mach 4 to 10 in the atmosphere. The aim was to build up experience in reuse operations and high-speed atmospheric flight. The demonstrator would weigh two tons and have a range of 1500 kilometers. It would be able to land on a conventional runway. Dassault and Aerospatiale Matra were to merge their VEHRA and ARES projects to produce a single design. Ares estimated cost was 550 million dollars.
  • Themis, a booster stage demonstrator, weighing 55 tonnes, to demonstrate integrated propellant tank technology. The demonstrator engine would be derived from the Vulcain of the Ariane 5. Estimated cost was up to 2.5 billion dollars. THEMIS would carry 33t of propellant, enough to reach Mach 11. Expendable boosters might permit orbital flight.

Development of the final commercial reusable launch vehicle (RLV) could cost between 7 to 16 billion dollars, up to twice that of Ariane 5. CNES calculations indicated that an RLV using Ariane 5 propulsion and materials technology would be no cheaper than the Ariane 5 itself. Therefore the need for the FLTP was clear to demonstrate new technology and provide the basis for a decision in 1997.

Thanks to Nicolas Pillet for providing images and information for this entry.


Launch Vehicle: Astroliner.

The Kelly Space & Technology Astroliner Space Launch System was a two-stage-to-orbit, towed space launch concept. Towing an aerodynamic vehicle to an altitude of 6,000 m yielded higher system performance due to vacuum engine performance, reduced drag and gravity losses, and aerodynamic lift during flight. After separation from the 747 towing aircraft at 6,000 m and Mach 0.8, the Astroliner would boost itself to 2750 m/s and 110 km altitude before releasing an expendable upper stage (4.2 m diameter x 7.6 m long) and payload (4.85 meter diameter x 7.56 meter long). The upper stage was capable of delivering a 5,000 kg payload into a 185 km 28.5° orbit at a cost per launch of $ 22 million - 40% of the cost of existing launchers.


Launch Vehicle: Pathfinder.

Pioneer Rocketplane planned in the late 1990's to produce the Pathfinder aerial propellant transfer spaceplane. Pathfinder was a two-seat fighter-bomber-sized aircraft powered by two turbofan engines and one kerosene/oxygen-burning RD-120 rocket engine. The Pathfinder aircraft was designed to take off with its turbofan engines, and climb to approximately 6,000 m where it would rendezvous with a tanker aircraft. The tanker would transfer 59 tonnes of liquid oxygen to the Pathfinder. After disconnecting from the tanker, the spaceplane ignited its rocket engine and climbed to an altitude of 110 km and a speed of Mach 15. Now on a suborbital trajectory outside the atmosphere, Pathfinder would open its payload bay doors, and release the payload with a liquid rocket upper stage. An expendable solid propellant upper stage could deliver a 2100 kg payload to a 300 km 30 degree orbit. Meanwhile Pathfinder would close its payload bay doors and re-enter the atmosphere. After slowing down to subsonic speeds, the turbofan engines would be restarted and the aircraft flown to a landing field. It was estimated that the price per launch could profitably be set as low as $7 million, 3 to 4 times lower than the price using the Taurus expendable launch vehicle.


Launch Vehicle: Venturestar. Production reusable single-stage-to-orbit launch vehicle using technology developed in X-33 testbed.

Back to Index
Last update 3 May 2001.
Contact Mark Wade with any corrections or comments.
Conditions for use of drawings, pictures, or other materials from this site..
© Mark Wade, 2001 .