|Country||Soviet Union / Russia|
|Purpose||crewed orbital flight and reentry|
|Launch site(s)||Baikonur pad 110/37|
|Crew vehicle||Buran-class shuttle|
The Buran programme (Russian: , IPA: [b?'ran], "Snowstorm" or "Blizzard"), also known as the "VKK Space Orbiter programme" ("VKK" is for Russian: ?, "Air Space Ship"), was a Soviet and later Russian reusable spacecraft project that began in 1974 at the Central Aerohydrodynamic Institute in Moscow and was formally suspended in 1993. In addition to being the designation for the whole Soviet/Russian reusable spacecraft project, Buran was also the name given to Orbiter K1, which completed one uncrewed spaceflight in 1988 and was the only Soviet reusable spacecraft to be launched into space. The Buran-class orbiters used the expendable Energia rocket as a launch vehicle. They are generally treated as a Soviet equivalent of the United States' Space Shuttle, but in the Buran project, only the airplane-shaped orbiter itself was theoretically reusable.
The Buran programme was started by the Soviet Union as a response to the United States Space Shuttle program. The project was the largest and the most expensive in the history of Soviet space exploration. Development work included sending BOR-5 test vehicles on multiple sub-orbital test flights, and atmospheric flights of the OK-GLI aerodynamic prototype. Buran completed one uncrewed orbital spaceflight in 1988, after which it was recovered successfully. Although the Buran class was similar in appearance to NASA's Space Shuttle orbiter, and could similarly operate as a re-entry spaceplane, its internal and functional design was distinct. For example, the main engines during launch were on the Energia rocket and were not taken into orbit by the spacecraft. Smaller rocket engines on the craft's body provided propulsion in orbit and de-orbital burns, similar to the Space Shuttle's OMS pods.
The Buran orbital vehicle programme was developed in response to the U.S. Space Shuttle programme, which in the 1980s raised considerable concerns among the Soviet military and especially Defense Minister Dmitry Ustinov. An authoritative chronicler of the Soviet and later Russian space programmes, the academic Boris Chertok, recounts how the programme came into being. According to Chertok, after the U.S. developed its Space Shuttle programme, the Soviet military became suspicious that it could be used for military purposes, due to its enormous payload, several times that of previous U.S. launch vehicles. The Soviet government asked the TsNIIMash (?, Central Institute of Machine-building, a major player in defense analysis) for an expert opinion. Lieutenant General Yuri Mozzhorin recalled that by "approximately 1965," when the Soviet Union had the 'long arm' (ICBMs), the Soviets did not expect war "and thought it would not happen." As institute director, Mozzhorin, recalled that for a long time the institute could not envisage a civilian payload large enough to require a vehicle of that capacity.
Officially, the Buran orbital vehicle was designed for the delivery to orbit and return to Earth of spacecraft, cosmonauts, and supplies. Both Chertok and Gleb Lozino-Lozinskiy (Chief Designer of RKK Energia) suggest that from the beginning, the programme was military in nature; however, the exact military capabilities, or intended capabilities, of the Buran programme remain classified. Commenting on the discontinuation of the programme in his interview to New Scientist, Russian cosmonaut Oleg Kotov confirms their accounts:
We had no civilian tasks for Buran and the military ones were no longer needed. It was originally designed as a military system for weapon delivery, maybe even nuclear weapons. The American shuttle also has military uses.
Like its American counterpart, the Buran orbital vehicle, when in transit from its landing sites back to the launch complex, was transported on the back of a large jet aeroplane - the Antonov An-225 Mriya transport aircraft, which was designed in part for this task and remains the largest aircraft in the world to fly multiple times. Before the Mriya was ready (after the Buran had flown), the Myasishchev VM-T Atlant, a variant on the Soviet Myasishchev M-4 Molot (Hammer) bomber (NATO code: Bison), fulfilled the same role.
The Soviet reusable space-craft programme has its roots in the very beginning of the space age, the late 1950s. The idea of Soviet reusable space flight is very old, though it was neither continuous, nor consistently organized. Before Buran, no project of the programme reached production.
The idea saw its first iteration in the Burya high-altitude jet aircraft, which reached the prototype stage. Several test flights are known, before it was cancelled by order of the Central Committee. The Burya had the goal of delivering a nuclear payload, presumably to the United States, and then returning to base. The cancellation was based on a final decision to develop ICBMs. The next iteration of the idea was Zvezda from the early 1960s, which also reached a prototype stage. Decades later, another project with the same name was used as a service module for the International Space Station. After Zvezda, there was a hiatus in reusable projects until Buran.
The development of the Buran began in the early 1970s as a response to the U.S. Space Shuttle program. Soviet officials were concerned about a perceived military threat posed by the U.S. Space Shuttle. In their opinion, the Shuttle's 30-ton payload-to-orbit capacity and, more significantly, its 15-ton payload return capacity, were a clear indication that one of its main objectives would be to place massive experimental laser weapons into orbit that could destroy enemy missiles from a distance of several thousands of kilometers. Their reasoning was that such weapons could only be effectively tested in actual space conditions and that to cut their development time and save costs it would be necessary to regularly bring them back to Earth for modifications and fine-tuning. Soviet officials were also concerned that the U.S. Space Shuttle could make a sudden dive into the atmosphere to drop bombs on Moscow.
Soviet engineers were initially reluctant to design a spacecraft that looked superficially identical to the Shuttle, but subsequent wind tunnel testing showed that NASA's design was already ideal. Even though the Molniya Scientific Production Association proposed its Spiral programme design (halted 13 years earlier), it was rejected as being altogether dissimilar from the American shuttle design. While NPO Molniya conducted development under the lead of Gleb Lozino-Lozinskiy, the Soviet Union's Military-Industrial Commission, or VPK, was tasked with collecting all data it could on the U.S. Space Shuttle. Under the auspices of the KGB, the VPK was able to amass documentation on the American shuttle's airframe designs, design analysis software, materials, flight computer systems and propulsion systems. The KGB targeted many university research project documents and databases, including Caltech, MIT, Princeton, Stanford and others. The thoroughness of the acquisition of data was made much easier as the U.S. shuttle development was unclassified.
The construction of the shuttles began in 1980, and by 1984 the first full-scale Buran was rolled out. The first suborbital test flight of a scale-model (BOR-5) took place as early as July 1983. As the project progressed, five additional scale-model flights were performed. A test vehicle was constructed with four jet engines mounted at the rear; this vehicle is usually referred to as OK-GLI, or as the "Buran aerodynamic analogue". The jets were used to take off from a normal landing strip, and once it reached a designated point, the engines were cut and OK-GLI glided back to land. This provided invaluable information about the handling characteristics of the Buran design, and significantly differed from the carrier plane/air drop method used by the United States and the Enterprise test craft. Twenty-four test flights of OK-GLI were performed by the Gromov Flight Research Institute test pilots and researchers after which the shuttle was "worn out". The developers considered using a couple of Mil Mi-26 helicopters to "bundle" lift the Buran, but test flights with a mock-up showed how risky and impractical that was. The VM-T ferried components and the Antonov An-225 Mriya (the heaviest airplane ever) was designed and used to ferry the shuttle.
The flight and ground-testing software also required research. In 1983 the Buran developers estimated that the software development would require several thousand programmers if done with their existing methodology (in assembly language), and they appealed to Keldysh Institute of Applied Mathematics for assistance. It was decided to develop a new high-level "problem-oriented" programming language. Researchers at Keldysh developed two languages: PROL2 (used for real-time programming of onboard systems) and DIPOL (used for the ground-based test systems), as well as the development and debugging environment SAPO PROLOGUE. There was also an operating system known as Prolog Manager. Work on these languages continued beyond the end of the Buran project, with PROL2 being extended into SIPROL, and eventually all three languages developed into DRAKON which is still in use in the Russian space industry. A declassified May 1990 CIA report citing open-source intelligence material states that the software for the Buran spacecraft was written in "the French-developed programming language known as Prolog", possibly due to confusion with the name PROLOGUE.
Until the end of the Soviet Union in 1991, seven cosmonauts were allocated to the Buran programme and trained on the OK-GLI ("Buran aerodynamic analogue") test vehicle. All had experience as test pilots. They were: Ivan Ivanovich Bachurin, Alexei Sergeyevich Borodai, Anatoli Semyonovich Levchenko, Aleksandr Vladimirovich Shchukin, Rimantas Antanas Stankevi?ius, Igor Petrovich Volk and Viktor Vasiliyevich Zabolotsky.
A rule, set in place for cosmonauts because of the failed Soyuz 25 of 1977, insisted that all Soviet space missions contain at least one crew member who has been to space before. In 1982, it was decided that all Buran commanders and their back-ups would occupy the third seat on a Soyuz mission, prior to their Buran spaceflight. Several people had been selected to potentially be in the first Buran crew. By 1985, it was decided that at least one of the two crew members would be a test pilot trained at the Gromov Flight Research Institute (known as "LII"), and potential crew lists were drawn up. Only two potential Buran crew members reached space: Igor Volk, who flew in Soyuz T-12 to the space station Salyut 7, and Anatoli Levchenko who visited Mir, launching with Soyuz TM-4 and landing with Soyuz TM-3. Both of these spaceflights lasted about a week.
Levchenko died of a brain tumour the year after his orbital flight, Bachurin left the cosmonaut corps because of medical reasons, Shchukin was assigned to the back-up crew of Soyuz TM-4 and later died in a plane crash, Stankevi?ius was also killed in a plane crash, while Borodai and Zabolotsky remained unassigned to a Soyuz flight until the Buran programme ended.
Igor Volk was planned to be the commander of the first crewed Buran flight. There were two purposes of the Soyuz T-12 mission, one of which was to give Volk spaceflight experience. The other purpose, seen as the more important factor, was to beat the United States and have the first spacewalk by a woman. At the time of the Soyuz T-12 mission the Buran programme was still a state secret. The appearance of Volk as a crew member caused some, including the British Interplanetary Society magazine Spaceflight, to ask why a test pilot was occupying a Soyuz seat usually reserved for researchers or foreign cosmonauts.
Anatoli Levchenko was planned to be the back-up commander of the first crewed Buran flight, and in March 1987 he began extensive training for his Soyuz spaceflight. In December 1987, he occupied the third seat aboard Soyuz TM-4 to Mir, and returned to Earth about a week later on Soyuz TM-3. His mission is sometimes called Mir LII-1, after the Gromov Flight Research Institute shorthand. When Levchenko died the following year, it left the back-up crew of the first Buran mission again without spaceflight experience. A Soyuz spaceflight for another potential back-up commander was sought by the Gromov Flight Research Institute, but never occurred.
Maintenance, launches and landings of the Buran-class orbiters were to take place at the Baikonur Cosmodrome in the Kazakh S.S.R. Several facilities at Baikonur were adapted or newly built for these purposes:
Following a series of atmospheric test flights using the jet-powered OK-GLI prototype, the first operational spacecraft (Orbiter K1) flew one test mission on 15 November 1988 at 03:00:02 UTC. The spacecraft was launched uncrewed from and landed at Baikonur Cosmodrome in the Kazakh S.S.R. and flew two orbits, travelling 83,707 kilometres (52,013 mi) in 3 hours and 25 minutes (0.14 flight days).Buran never flew again; the programme was cancelled shortly after the dissolution of the Soviet Union. In 2002, the collapse of the hangar in which it was stored destroyed the Buran orbiter.
An aerodynamic testbed, OK-GLI, was constructed in 1984 to test the in-flight properties of the Buran design. Unlike the American prototype Enterprise, OK-GLI had four AL-31 turbofan engines fitted, meaning it was able to fly under its own power.
|Flight date||Mission||Shuttle||Crew||Duration||Landing Site||Notes||Sources|
|10 November 1985||OK-GLI||2||00d 00h 12m||Baikonur|||
|3 January 1986||OK-GLI||2||00d 00h 36m||Baikonur|
|27 May 1986||OK-GLI||2||00d 00h 23m||Baikonur|
|11 June 1986||OK-GLI||2||00d 00h 22m||Baikonur|
|20 June 1986||OK-GLI||2||00d 00h 25m||Baikonur|
|28 June 1986||OK-GLI||2||00d 00h 23m||Baikonur|
|10 December 1986||OK-GLI||2||00d 00h 24m||Baikonur||First automatic landing|
|23 December 1986||OK-GLI||2||00d 00h 17m||Baikonur|
|29 December 1986||OK-GLI||2||00d 00h 17m||Baikonur|
|16 February 1987||OK-GLI||2||00d 00h 28m||Baikonur|
|21 May 1987||OK-GLI||2||00d 00h 20m||Baikonur|
|25 June 1987||OK-GLI||2||00d 00h 19m||Baikonur|
|5 October 1987||OK-GLI||2||00d 00h 21m||Baikonur|
|15 October 1987||OK-GLI||2||00d 00h 19m||Baikonur|
|16 January 1988||OK-GLI||2||Baikonur|
|24 January 1987||OK-GLI||2||Baikonur|
|23 February 1988||OK-GLI||2||00d 00h 22m||Baikonur|
|4 March 1988||OK-GLI||2||00d 00h 32m||Baikonur|
|12 March 1988||OK-GLI||2||Baikonur|
|23 March 1988||OK-GLI||2||Baikonur|
|28 March 1988||OK-GLI||2||Baikonur|
|2 April 1988||OK-GLI||2||00d 00h 20m||Baikonur|
|8 April 1988||OK-GLI||2||Baikonur|
|15 April 1988||OK-GLI||2||00d 00h 19m||Baikonur|
|No||Launch Date||Mission||Shuttle||Crew||Duration||Landing Site||Notes||Sources|
|1||15 November 1988
|1K1||Buran||0||00d 3h 25m||Baikonur||
The only orbital launch of the Orbiter K1 Buran (also known as ""OK-1K1" or "Shuttle 1.01") was at 3:00 UTC on 15 November 1988 from pad 110/37 in Baikonur. The uncrewed craft was lifted into orbit by the specially designed Energia booster rocket. The life support system was not installed and no software was installed on the CRT displays. The shuttle orbited the Earth twice in 206 minutes of flight. On its return, it performed an automated landing on the shuttle runway at Baikonur Cosmodrome.
The planned flights for the shuttles in 1989, before the downsizing of the project and eventual cancellation, were:
The planned uncrewed second flight of Ptichka was changed in 1991 to the following:
After the first flight of a Buran shuttle, the project was suspended due to lack of funds and the political situation in the Soviet Union. The two subsequent orbiters, which were due in 1990 (informally Ptichka) and 1992 (informally Baikal) were never completed. The project was officially terminated on 30 June 1993, by President Boris Yeltsin. At the time of its cancellation, 20 billion rubles had been spent on the Buran programme.
The programme was designed to boost national pride, carry out research, and meet technological objectives similar to those of the U.S. Space Shuttle programme, including resupply of the Mir space station, which was launched in 1986 and remained in service until 2001. When Mir was finally visited by a space shuttle, the visitor was a U.S. Shuttle, not Buran.
On 12 May 2002, a hangar roof at the Baikonur Cosmodrome in Kazakhstan collapsed because of a structural failure due to poor maintenance. The collapse killed 8 workers and destroyed one of the Buran craft (Orbiter K1), which flew the test flight in 1988, as well as a mock-up of an Energia booster rocket. It was not clear to outsiders at the time which Buran programme craft was destroyed, and the BBC reported that it was just "a model" of the orbiter. It occurred at the MIK RN/MIK 112 building at Site 112 of the Baikonur Cosmodrome, 14 years after the first and only Buran flight. Work on the roof had begun for a maintenance project, whose equipment is thought to have contributed to the collapse. Also, before the day of collapse, there had been several days of heavy rain.
Five orbiters were planned to be built, (designated 1K-5K, K stands for (rus: "Korabl"),"Craft, flying article", and hull numbering starts with 1 or 2 (e.g.1.01), two originally ordered in 1970s and three ("second series") additionally ordered in 1983. For research and testing purposes, several test articles produced, designated 1M-8M (M stands for "Mock-up"), hull numbering starts with 0 (e.g.0.02).
By 1991 two operational vehicles were delivered to Baikonur, three others were under construction at Tushino.
|First flight article, first spaceplane series||Baikonur Cosmodrome Site 110/37 (L) at Baikonur|| 1988
|Spaceplane not visible; no available satellite photos.||15 November 1988||Built in 1986, only flightworthy orbiter. Launched on an uncrewed, remote controlled flight; two orbits and landing (with heavy crosswinds and a self-initiated approach direction change) at Yubileiniy (Jubilee) Airport, Baikonur.|
|MIK building, Baikonur Cosmodrome, Kazakhstan|| 2002||Spaceplane not visible; shadows.||1988 to 2002||Housed in MIK building in area 112, Baikonur with an Energia booster mockup and other Energia hardware, destroyed in a roof collapse on 12 May 2002, which killed eight workers.|
|Second flight article, first series, 95-97% complete||MIK building, Baikonur Cosmodrome, Kazakhstan||||Shuttle not visible, in building.||1988 to 2002||Built in 1988, housed adjacent to the Buran.|
|MZK building 80, area 112a, Baikonur|| 2015||Spaceplane not visible; in building.||2002 to present||Moved to the MZK after the roof collapse in the MIK.|
|First flight article, second series, 30-50% complete||Inside Tushino Plant, Moscow, Russia||1991 to 2006||Built 1991.|
|Car park on Kimki Reservoir, near plant.|| 2007-2011||Need history.||2006 to 2011||Moved outdoors.|
|Zhukovsky Airport, near Moscow, Russia||2011||on 15 August 2011; use history.||2011 to present||An exhibit in the MAKS-2011 and later air shows. Zhukovsky International Airport is the site of the Gromov Flight Research Institute, and has become a large outdoor flight museum. Other sightings:|
on 15 March 2012: ,
on 31 July 2012 and 8 May 2013 ,
on 4 June and 29 July 2014 ,
on 11 September 2016 through 2020 .
|Second flight article, second series, 10-20% complete.||Tushino plant, Moscow, Russia||||1991-present||Build started 1991, some pieces of 2.02, like heat tiles, have found their way onto eBay.|
|Third flight article, second series, very small amount assembled||Scattered.||1988 to present||All parts have been scattered and are unidentifiable.|
|Airframe and shake test bed article||Outdoor pad, area 112, Baikonur Cosmodrome, Kazakhstan||||Use history.||1988 to January 2007||Built in 1982, deteriorated considerably outdoors on pad.|
|Gagarin Museum, Baikonur Cosmodrome, Kazakhstan||2007||January 2007 to present||Refurbished in 2007, now on outdoor display.|
|Atmospheric test article, two extra jet engines in rear to facilitate take-off.||Ramenskoye Airport, Moscow||No history available this far back.||1999||Built in 1984, used in 25 test flights. On display at MAKS-1999, Russia's most prestigious airshow.|
|Pyrmont Island, Sydney harbor, Australia|| 2000
|Use history to see shelter; shuttle not visible.||February 2000 to September 2000; afterwards stored on the site until about Oct 2002||Sold and sent in February 2000 to the Sydney, Australia 2000 Olympic Games. Displayed inside a light structure, stored outdoors there afterwards.|
|Manama harbor, Bahrain||Use history.||July 2004 to 2007||Stored outdoors in Bahrain while the ownership of the spaceplane was legally contended.|
|Technik Museum, Speyer, Germany||2008||Shuttle not visible; in building.||2008 to present||Purchased from Roscosmos State Corporation when it won the legal battle, displayed indoors.|
|Electrical test article.||Checkout and Test Building (KIS), RKK Energia Plant, Korolev, Russia||||Not visible, in building. This location shows a half-scale memorial of Energia and the Buran, perhaps meant to be replaced.||2006 to 15 October 2012||Built in 1982. Stored inside.|
|Grounds of the RKK Energia plant||15 October 2012 to June 2017||Stored outside by 15 October 2012, intended to be placed on permanent display.|
|Sirius Science Center, Sochi, Krasnodar Krai, Russia||2018||June 2017 to current||On permanent outdoor display at the Sirius Science Center in Sochi, Russia.|
|Engineering mockup||MZK building, Baikonur Cosmodrome, Kazakhstan|| 2014||Spaceplane not visible; in building.||1988 to present||Built in 1983.|
|Environmental test parts from forward fuselage||Unknown||1988 to present||Destroyed, parts used for OK-TVA.|
|Environmental test article||NIIKhimMash rocket test area, near Moscow, Russia||||1988 to present|
|Structural test article||Gorky Park, Moscow, Russia||2010||Use history.||1995 to July 2014||Served as an attraction, a small restaurant, and a bicycle storage, as part of the amusement park at that site.|
|Outside Pavilion 20 about 250 meters south of the Vostok rocket, VDNKh/VVT (All-Russia Exhibition Center)||2014||Use history.||July 2014 to present||Moved to VDNKh on 5 July 2014, assembled by 21 July. The shuttle acquisition is part of VDNKh refurbishment.|
|Components used for static thermal and vacuum tests.||Outdoor display at Clinical Hospital No. 83 FMBA on Orekhovy Boulevard in Moscow.||2012||2012 (at least) to present|
|Unnamed||Wooden wind tunnel model, 1/3 scale.||Ramenskoye Airport, near Moscow, Russia, photographed in 2013.||2013||up to 2013||Has been destroyed in or after 2013. Photographed at Zhukovsky Airfield by Aleksander Makin.|
|Image||Name||Construction Date||Usage||Current status|
|BOR-4||1982-1984||Sub-scale model of the Spiral space plane||1:2 scale model of Spiral space plane. 5 launches. NPO Molniya, Moscow.|
|BOR-5 ("Kosmos")||1983-1988||Suborbital test of 1/8 scale model of Buran||5 launches, none were reflown but at least 4 were recovered. NPO Molniya, Moscow.|
|Wind tunnel models||Scales from 1:3 to 1:550||85 models built; see unnamed test article in table above.|
|Gas dynamics models||Scales from 1:15 to 1:2700|
The 2003 grounding of the U.S. Space Shuttles caused many to wonder whether the Russian Energia launcher or Buran shuttle could be brought back into service. By then, however, all of the equipment for both (including the vehicles themselves) had fallen into disrepair or been repurposed after falling into disuse with the collapse of the Soviet Union.
In 2010 the director of Moscow's Central Machine Building Institute said the Buran project would be reviewed in the hope of restarting a similar crewed spacecraft design, with rocket test launches as soon as 2015. Russia also continues work on the PPTS but has abandoned the Kliper program, due to differences in vision with its European partners.
Due to the 2011 retirement of the American Space Shuttle and the need for STS-type craft in the meantime to complete the International Space Station, some American and Russian scientists had been mulling over plans to possibly revive the already-existing Buran shuttles in the Buran programme rather than spend money on an entirely new craft and wait for it to be fully developed but the plans did not come to fruition.
On the 25th anniversary of the Buran flight in November 2013, Oleg Ostapenko, the new head of Roscosmos, the Russian Federal Space Agency, proposed that a new heavy lift launch vehicle be built for the Russian space program. The rocket would be intended to place a payload of 100 tonnes (220,000 lb) in a baseline low Earth orbit and is projected to be based on the Angara launch vehicle technology.
The cockpit is an all-metal welded pressurised compartment houses the crew's workplaces, control and life support systems. It has three decks. The upper deck, Command Module,is the workspace for the crew and serves to accommodate commander, pilot, engineer and mission specialist's seats, as well as dashboard and RMS operator's workplace. The middeck is intended to place life support and auxiliary equipment Up to 6 crewmembers could be seated there during launch and reentry as well. The lower deck houses the power systems. 
Docking compartment, SM (rus? , ) mounted into rear part of payload bay. It is a spherical compartment with a diameter of 2.67 m, in the upper part passes into a cylindrical tunnel with an androgynous peripheral docking unit (APAS-89) installed on it. Unlike US Space Shuttle, docking compartment for Buran features extrendable tunnel to increase clearance between orbiter and the station. Another hatch, facing to payload bay, was to support extravehicular activity from the orbiter.
SBM (rus ?, Onboard Manipulator System), similar to Space Shuttle's RMS was developed at the Central Research and Development Institute for Robotics and Technical Cybernetics to support operations with payload. It could be operated both in manual and automatic modes. Buran-class orbiter could carry, depending on the mission, one or two manipulator arms. 
To expand Buran's capabilities, pressurised modules, similar to ESA's Spacelab was designed based on 37K design. These modules had to be both compartments to conduct experiments and logistics volume, cold be either mounted in payload bay and connected to the crew cabin via tunnel or to be temporarily docked to Mir's Kristall's side docking port. On Buran's maiden flight, the Accessory Unit (rus ) 37KB No37070 was installed into orbiter's payload bay. It carried recording equipment and accumulators providing power to onboard systems as the regular fuel cells based power system was not ready at the time. Second 37KB No37071 was built in 1987. It was planned to build third 37KB No37072, but this was never happened because of program cancellation. 
Orbital maneuvering is provided by Joint Propulsion System, ODU (rus: , ) 
Unlike the US Space Shuttle, which was propelled by a combination of solid boosters and the shuttle orbiter's own liquid-fuel engines fueled from a large fuel tank, the Soviet/Russian shuttle system used thrust from the rocket's four RD-170 liquid oxygen/kerosene engines developed by Valentin Glushko and another four RD-0120 liquid oxygen/liquid hydrogen engines.
Because Buran's debut followed that of Columbia, and because there were striking visual similarities between the two shuttle systems--a state of affairs which recalled the similarity between the Tupolev Tu-144 and Concorde supersonic airliners--many speculated that Cold War espionage played a role in the development of the Soviet shuttle. Despite remarkable external similarities, many key differences existed, which suggests that, had espionage been a factor in Buran's development, it would likely have been in the form of external photography or early airframe designs. One CIA commenter states that Buran was based on a rejected NASA design. See the § Programme development section above.