The Buran programme (, , ) was a Soviet and later Russian reusable spacecraft project to develop the Energia-Buran system, officially known as the Reusable Space System "Buran" (), that formally began in 1976 and was 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 1K, which completed one uncrewed spaceflight in 1988 and was the only Soviet reusable spacecraft to be launched into space. The Buran orbiters used the expendable Energia rocket as a launch vehicle.
The Buran programme was started by the Soviet Union as a response to the United States Space Shuttle programme. The latter's unclassified nature was a boon for the Soviets and resulted in many superficial and functional similarities between American and Soviet shuttle designs. Although the Buran orbiter was similar in appearance to NASA's Space Shuttle orbiter, and could similarly operate as a re-entry spaceplane, its final internal and functional design was different. 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. Unlike the Space Shuttle whose first orbital spaceflight was accomplished in April 1981, Buran, whose first and only spaceflight occurred in November 1988, had a capability of flying uncrewed missions, as well as performing fully automated landings.The Space Shuttle could not perform uncrewed missions but was capable of fully automatic landing up to the point of ground rollout, during which the Pilot would have to steer the orbiter down the runway centerline. A test demonstration of this autoland capability was planned, but, as recounted by former NASA Space Shuttle Program Manager Wayne Hale, who was a flight controller at JSC on that shuttle mission, the test was cancelled while the orbiter was already on orbit, by the action of an admiral who insisted that the test posed an unnecessary and unreasonable risk to the crew. (Source: Wayne Hale's NASA blog) The project was the largest and the most expensive in the history of Soviet space exploration.
Background The Soviet reusable spacecraft programme has its roots in the late 1950s, at the very beginning of the space age. The idea of Soviet reusable space flight is very old, though it was neither continuous nor consistently organised. Before Buran, no project of the programme reached operational status.
The first step toward a reusable Soviet spacecraft was the 1954 Burya, a high-altitude prototype jet aircraft/cruise missile. Several test flights were made 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 Burya programme was cancelled by the USSR in favour of a decision to develop ICBMs instead. The next iteration of a reusable spacecraft was the Zvezda design, which also reached a prototype stage. Decades later, another project with the same name would be used as a service module for the International Space Station. After Zvezda, there was a hiatus in reusable projects until Buran.
The Buran orbital vehicle programme was developed in response to the U.S. Space Shuttle programme, which raised considerable concerns among the Soviet military and especially Defense Minister Dmitry Ustinov. An authoritative chronicler of the Soviet and later Russian space programme, 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. 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 (General Designer and General Director of NPO Molniya) 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.
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 was 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.
History of the Buran programme
Programme development The development of the Buran began in the early 1970s as a response to the U.S. Space Shuttle programme. 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 kilometres. 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 nuclear bombs on Moscow.
In 1974, Valentin Glushko's design bureau, OKB-1 (later NPO Energiya), proposed a new family of heavy-lift rockets called RLA (). The RLA concept included the use of kerosene and liquid hydrogen as fuel, and liquid oxygen as oxidizer (both new technologies in the Soviet space programme), with the shuttle orbiter being one possible payload. 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.
By 1975, NPO Energiya had come up with two competing designs for the orbiter vehicle: the MTKVP (), a 34-meter-long lifting body spaceplane launched on top of a stack of kerosene-fuelled strap on boosters; and the OS-120 (), a close copy of the US Space Shuttle based on US Space Shuttle documentation and designs obtained through the VPK and KGB. The OS-120 was a delta-winged spaceplane based heavily on the US Space Shuttle design, equipped with three liquid hydrogen engines, strapped to a detachable external tank and four liquid fuel boosters (NPO Energiya even considered the use of solid propellant rocket boosters, further imitating the US Shuttle's configuration).
A compromise between these two proposals was achieved by NPO Energiya in January 1976 with the OK-92 (), a delta-winged orbiter equipped with two Soloviev D-30 turbofan jet engines for autonomous atmospheric flight, launched to space from a rocket stack made of a core stage with three cryogenic engines, and four kerosene-fuelled boosters, each with four engines. By 1978, the OK-92 design was further refined, with its final configuration completed in June 1979.
Soviet engineers were initially reluctant to implement a spacecraft design with so many similarities to the US Space Shuttle. Although it has been commented that wind tunnel testing showed that NASA's design was already ideal, the shape requirements were mandated by its potential military capabilities to transport large payloads to low Earth orbit, themselves a counterpart to the Pentagon's initially projected missions for the Shuttle. 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.
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 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 programme, 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.
Flight crew preparation
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 Stankevičius, Igor Petrovich Volk, and Viktor Vasiliyevich Zabolotsky.