Category Energiya-Buran

Buran’s hydraulic system provided hydraulic pressure for positioning actuators needed to move the aerodynamic surfaces (elevons, body flap, rudder/speed brake), deploy the landing gear, operate the main landing gear brakes, and conduct nose wheel steering. Three independent hydraulic circuits were available to provide the necessary redundancy, with one being enough to safely land Buran. A four-circuit system was considered (as it was for the Space Shuttle Orbiter), but rejected due to weight considerations. Each circuit had a hydraulic pump and reservoir, containing

a hydraulic fluid. The hydraulic system was designed to operate in temperatures ranging from —60°C to +175°C. In order to keep the system warm enough in orbit, the hydraulic fluid was circulated periodically by an electric-motor-driven circulation pump to absorb heat from heat exchangers in each hydraulic circuit. To prevent the system from overheating during re-entry, each circuit was equipped with a water spray boiler.

Whereas airplanes use their engines to power the hydraulic pumps, gliders such as the Shuttle and Buran need Auxiliary Power Units (APUs) to perform the same function. Just like the Shuttle, Buran had three Auxiliary Power Units (Russian acronym VSU) in the aft fuselage. The VSUs were developed and built by NPO Molniya. They were fueled by hydrazine, which was decomposed in a gas turbine to produce a hot gas that powered a turbine that in turn ran a hydraulic pump. Engineers looked at several fuel combinations (tsiklin + an oxide, ammonia + nitrous oxide, hydrogen peroxide + hydrazine), but in the end settled for a hydrazine mono­propellant system, as on the Orbiter. The Russians probably made this decision before NASA realized that hydrazine-fueled APUs were not the best of choices. Aside from being a toxic fluid that requires special handling provisions, hydrazine is also a highly flammable chemical. This became all too apparent on the STS-9 mission in 1983, when a hydrazine leak caused a potentially catastrophic fire in Columbia’s aft fuselage only minutes before landing. The replacement of a hydra­zine-fueled APU by an electric APU was high on NASA’s priority list of Shuttle upgrades before the 2003 Columbia accident.

Having a dry mass of 235 kg, each VSU consisted of a fuel unit, the power unit itself, and a system controller. The fuel unit and power unit were built as one integrated system, two located on the left inner wall of the aft fuselage and one on the right inner wall. The system controllers were installed in an equipment bay at the base of the aft fuselage.

The fuel unit contained a single tank with 180 kg of hydrazine and several gaseous nitrogen tanks. Nitrogen was stored in these tanks at a pressure of 32 megapascals (MPa) and first passed through a pressure regulator where the pressure was reduced to 3.5 MPa before it entered the fuel tank to push the hydrazine to the power unit. Each fuel unit was hermetically sealed to prevent any hydrazine leakage into the aft fuselage of Buran. To minimize the fire hazard, the enclosure was purged with nitrogen during re-entry beginning at an altitude of 30 km.

The main elements of the power unit itself were the gas generator, the turbine, and an oil tank. In the gas generator the hydrazine passed over a catalyst bed, which decomposed it into a hot gas that drove a single-stage turbine. While the gas was vented overboard via an exhaust duct, a double-reduction gear reduced the turbine speed from 55,000 rpm to 4,500 rpm before the mechanical drive was imparted to the hydraulic pump. Oil was circulated through the system to lubricate and cool the gear-box and the turbine bearings.

The main difference between the Shuttle’s APUs and Buran’s VSUs is that the latter used a pressure-fed system rather than a pump to deliver the hydrazine to the gas generator. While the pressure-fed system consumes a slightly larger amount of fuel, it is less prone to fires and other serious malfunctions. Also, in the Shuttle the

fuel tanks are in different locations than the power units, complicating the plumbing and increasing the fire hazard.

The VSUs were designed to operate continuously for a maximum of 75 minutes. Because of the absence of main engines on Buran, the VSUs were not needed for gimbaling the main engine nozzles as was the case for the Shuttle’s APUs. However, the VSUs were still started shortly before launch to enable the vehicle to make an emergency landing in certain abort scenarios. They were shut down about 200 seconds into the launch because at that point Buran had enough energy to reach orbit if one or more core stage engines failed. After an in-orbit check-out the VSUs were not reactivated until after the deorbit burn at an altitude of about 100 km. On Shuttle missions one of the three APUs is activated before the deorbit burn, with the other two following afterwards [12].

For long-duration flights or flights requiring extra propellant reserves, it was possible to mount additional tanks in the payload bay. There was room for an additional fuel tank in the front of the bay and for an additional oxidizer tank (big or small) in the aft. These would have been placed such that the vehicle’s center of gravity was not disturbed. The additional tanks could have increased Buran’s overall propellant load from 7.5 tons to 14 tons, allowing the vehicle to reach an altitude of up to 1,000 km. Plans for a comparable “OMS kit’’ in the Shuttle Orbiter’s payload bay were never implemented.

In order to counter evaporation of the cryogenic oxidizer, Buran’s ODU was filled with supercooled LOX at a temperature of —210°C (with LOX having a boiling point of approximately — 180°C). This, along with the use of several layers of thermal insulation and LOX-mixing techniques, was enough to prevent any significant boil-off for 15 to 20 days. On longer missions the LOX would have been maintained at proper temperatures by circulating cooled helium through the tank’s heat exchanger and also by installing a special cryocooler using the so-called reversed Stirling cycle.

The ODU had an elaborate fault detection and identification system, consisting among other things of about 100 sensors to measure pressures, temperatures, vibra­tions, etc. The engines could be shut down in a fraction of a second if a dangerous situation developed [21].

If one of the core stage engines failed after T + 3m10s, Buran could still reach orbit, but the exact scenario depended on when the failure occurred and how much propellant Buran’s DOM engines needed to achieve that orbit, something that was calculated by the on-board computers. If the failure happened late in the launch, Buran’s DOM engines could have boosted the vehicle to its nominal orbit or to a lower but still usable orbit (in NASA parlance the latter scenario is called “Abort to Orbit’’, performed once by Challenger on STS-51F in July 1985). If it occurred much earlier, the remaining propellant in the core stage would have been burned to depletion, with Buran then firing its DOM engines to reach a very low orbit and somewhat later re-igniting those engines to initiate re-entry. Excess DOM propellant would have been expended prior to entry interface to meet center-of-gravity require­ments. This “Single-Orbit Trajectory” (OT) abort is the same as an Abort Once Around (AOA) on Shuttle launches [31].

Even as the VM-T Atlant began its test flight program, the Russians continued to study more capable carrier aircraft that could transport elements of the Energiya – Buran system in one piece. Since no existing aircraft was capable of doing that, it was clear that the only way out of this problem was to develop a dedicated airplane. Not only would such an aircraft transport elements of Energiya-Buran, it could also serve as a launch platform for small air-launched reusable spacecraft that NPO Molniya

had begun studying in the late 1970s/early 1980s. These studies (“System 49” and “Bizan”) initially focused on the use of the An-124 Ruslan, but it eventually turned out that a more capable aircraft would be required (see Chapter 9).

All this led to the idea to build a heavier version of the Ruslan that eventually became known as the An-225 or Mriya (Ukrainian for “dream”). By the summer of 1984, after just about one year of work, engineers at the Antonov bureau had nailed down the basic design details. The plane would have forward and aft fuselage plugs to increase length as well as wing inserts to extend span and allow the installation of two additional Lotaryov D-18T turbofans beyond the four usually flown on Ruslan. The number of main landing gear assemblies was increased from five per side to seven to handle the increased take-off weight. This resulted in a 32-wheel landing gear system (two nose and fourteen main wheel bogies, seven per side, each with two wheels). The conventional tail assembly of the An-124 was changed to a twin-fin assembly to ensure controllability with a large cargo mounted on the back. This also obviated the need for covering the aft section of Buran with a tail cone (as was the case on the VM-T). The rear loading ramp was deleted to reduce weight, but the front loading ramp was retained. Payloads could be installed inside its 47 m long and 6.4 m wide cargo hold or on the back of the plane, in which case they could be 7-10 m in diameter and 70 m long. With a maximum take-off weight of 600 tons and a maximum payload capacity of 250 tons, the An-225 would become the biggest cargo plane in the world. It could easily transport a fully outfitted Buran vehicle, a complete Energiya core stage, or a complete Energiya strap-on booster. Judging by drawings published at the time, there were also plans to transport space station modules atop Mriya in giant cargo canisters.

The An-225 project received strong support from Pyotr V. Balabuyev, who became the new head of the Antonov design bureau in 1984 and played a vital role

in getting it approved. The final go-ahead came in a government and party decree issued on 20 May 1987 (nr. 587-132). Constructed from a production An-125, the first Mriya (tail number CCCP-82060) was first rolled out just 1.5 years later, on 30 November 1988. After several taxi tests and take-off runs, the aircraft made its maiden test flight from the Antonov bureau’s airfield at Svyatoshino on 21 December 1988. Piloted by a seven-man crew, it smoothly touched down after a 1 hour 14 minute flight that accomplished all test objectives. Coming just about a month after the inaugural flight of Buran, Mriya’s successful debut was announced by the Soviet media the very same day. In early February 1989 it was first shown to Soviet and foreign journalists at the Kiev airport “Borispol”, where it was even briefly inspected by Mikhail Gorbachov. On 22 March 1989 the An-225 made an historic test flight that broke more than 100 aviation records, the most important being the highest take-off mass ever achieved. Carrying a payload of 155 tons, the aircraft weighed 508 tons, exceeding the previous record (set by a Boeing 747-400) by more than 100 tons.

Several weeks later the Mriya flew to Baykonur for a series of brief test flights with the flown Buran vehicle in the first half of May 1989. Then, on 21 May, the 560-ton combination took off for a 4 hour 25 minute flight from the cosmodrome to Kiev, covering a total distance of 2,700 km. Two days later the combination flew to the Moscow area for a short stay in Zhukovskiy before returning back to Kiev. On 7 June Mriya and Buran made a 3.5 hour non-stop flight to Le Bourget to become the star attraction of the 38th Paris Air Show. Observers were surprised to see Buran being flown into Le Bourget through light rainfall. NASA’s Space Shuttle Orbiter is

never flown through rainfall or even through clouds while being ferried by the Boeing 747 Shuttle Carrier Aircraft, with a weather reconnaissance aircraft flying about 150 km ahead to give adequate warning to the Boeing crew to avoid clouds and rain. No such weather reconnaissance aircraft accompanied Mriya/Buran to Paris, although French Mirage fighters met the combination as it entered French airspace and escorted it to Le Bourget. After a week at Le Bourget, Mriya returned Buran to Baykonur and then made a transatlantic flight to Canada in August to an air show in Vancouver.

Although Mriya made several more appearances at Western air shows (without Buran) in the early 1990s, it gradually lost its raison d’etre as the Soviet Union collapsed and the Energiya-Buran program was canceled. Construction of a second Mriya was discontinued and the only flown Mriya was grounded in April 1994 after having logged 339 flights lasting a total of 671 hours. Fourteen of those flights (28 hours 27 minutes) were with Buran. Mriya never flew any elements of the Energiya rocket. Plans to use Mriya as a launch platform for the British HOTOL spaceplane and NPO Molniya’s MAKS spaceplane never materialized either. Instead, Mriya was placed in storage and many of its parts were “cannibalized” for use on the An-124 Ruslan. Around the turn of the century the Antonov bureau spent $20 million to upgrade the aircraft with new avionics and other modern equipment. The updated An-225, operated jointly by Antonov Airlines and the British firm Air Foyle, entered service in May 2001 as a commercial transport for heavy and oversized freight. On 11 September 2001 the An-225 once again made history by carrying a record cargo of 253 tons [8].

The departmentalism of the Soviet space program was not only evident in the selection of cosmonauts for Buran, but also in the construction of simulators needed for cosmonaut training. About a dozen of these were scattered over various organ­izations involved in the Buran program, some of them apparently performing similar roles. For the Soyuz and space station programs, all simulator training was and still is concentrated at Star City, but this was hardly the case for Buran. Although there were ambitious plans for Buran simulator buildings at Star City and some simulators were eventually placed here, little if any Buran-related simulator training appears to have taken place at TsPK. Presumably, this was due to the fact that the Star City facilities were intended in the first place to prepare for manned orbital flights of Buran, which always remained a distant goal, without any really concrete flight plans ever being drawn up.

The bulk of the simulator training took place at NPO Molniya in Tushino and was aimed at preparing for the atmospheric landing tests with the BTS-002 Buran test vehicle. There where three simulators at NPO Molniya. Two of them were called PRSO (“Full-Scale Equipment Test Stand”) and installed on top of each other. PRSO-1 was mainly used for testing the software used during the BTS-002 landing tests. First activated in June 1984, it consisted of a simplified Buran cockpit and a “skeleton” containing the main parts involved in landing. PRSO-2 was supposed to

become the principal training device for Buran orbital missions, but was never completed [30].

The third simulator at NPO Molniya was PDST (“Piloting Dynamic Test Stand/ Simulator”), which was also geared to simulating the BTS-002 approach and landing tests. This was a Buran cockpit mounted on a motion platform, and housed all the displays and controls found in BTS-002. Installed behind the cockpit windows was a visual display system showing the surroundings of Zhukovskiy, where the test flights were conducted. A three-degrees-of-freedom motion platform was later replaced by a six-degrees-of-freedom motion platform, capable of imitating the movements made by the vehicle. PDST was used to familiarize crews both with nominal and off – nominal flight situations. Before the first approach and landing test in November 1985 the first four pilots involved in the tests (Volk, Stankyavichus, Levchenko, and Shchukin) each spent about 230-240 hours training on PDST, simulating about 160 off-nominal flight scenarios. In between training sessions PDST was also used to test new manual and flight director landing modes.

Another test stand at NPO Molniya was PSS (“Piloting Static Test Stand”). Completed in March 1984, it consisted of a Buran flight deck in a dome-shaped structure where images of the landing area were displayed on the walls with the help of a wide-angle projection system. It was solely used for research purposes, more particularly to test algorithms for manual flight control. It is not entirely clear if the LII test pilots were involved in this work [31].

Buran training at Star City was to take place in two buildings. One of these was called KTOK (“Orbiter Simulator Building”), which was planned to house a full-scale mock-up of Buran. Although that mock-up never appeared, three other simulators did end up in the facility.

The first was a motion base simulator designed and built by TsAGI that could be used to practice the controlled flight portion of the landing. In spite of the fact that this was probably one of the highest-performance Buran simulators built, it is remarkable that members of the various cosmonaut groups have stressed that they never trained on it [32]. The motion-base simulator was still intact in 1999, but by 2003 it had been largely dismantled and it has now been removed from the training hall.

The second simulator was a full-scale Buran crew cabin, consisting of both the flight and mid-decks. In addition, a Docking Module was added to the simulator that was to be used for docking to the Mir space station. This Docking Module was equipped with an APAS-89 docking system.

The third simulator was a fixed-base flight deck that was prominently positioned in the training hall. By 2003 it was still standing in the hall, although all equipment had been disconnected and the entrance door was sealed off.

After cancellation of the Buran program, other simulators were placed in the KTOK building in support of the Mir and ISS programs. These were full-scale

training models of Mir’s Spektr and Priroda modules and of the Russian ISS modules Zarya and Zvezda.

Construction of a second large Buran simulator building was begun at TsPK, but abandoned as the future of the program became uncertain. Over 20 m high, it never­theless is still one of TsPK’s most conspicuous buildings. If completed, it should have been able to house a complete Buran orbiter and would have been used among other things to train cosmonauts in operating the remote manipulator arm.

Another Buran cockpit simulator at TsPK was called Pilot-35 (“35” referring to the 11F35 designator of Buran), adapted from a Spiral simulator called Pilot-105. This was used mainly to test the placement of control and display systems in the cockpit and to compare automatic and flight director landing modes. It was also used in conjunction with the TsF-7 centrifuge to test manual landing techniques under simulated flight conditions. However, Pilot-35 appears to have been intended primarily for engineering purposes and it is not clear if it was ever used by cosmo­nauts [33].

The Buran pilots also conducted extensive training at TsAGI in Zhukovskiy, using a simulator known as PSPK-102. Constructed in 1983, it was a dynamic simulator mounted on a six-degrees-of-freedom motion platform and was later modified as a simulator for various aircraft [34].

Buran pilots also simulated manual approach and docking techniques on a simulator called Pilot at IMBP. In addition, there were test stands at several organ­izations that were primarily built for engineering purposes, but were at least partially intended for cosmonaut training as well, although it is unclear whether they were ever actually used for that purpose. These included the full-scale Buran mock-up OK-KS and the crew cabin mock-up MK-KMS at NPO Energiya as well as the crew cabin mock-up MK-M at Myasishchev’s EMZ (see Chapter 6). At least three tests stands intended partially for cosmonaut training (KS-SU, ATsK, and Anomaliya) were situated at NPO AP in Moscow, the bureau that was responsible for Buran’s computers.

The dispersion of simulators over so many organizations was obviously not convenient for the LII pilots themselves, who were based in Zhukovskiy. Especially after the formation in 1987 of OKPKI, which was supposed to become LII’s equivalent of TsPK, there were calls to concentrate simulator training there, but to no avail [35].

Even as the Zenit was slowly overcoming its teething problems, tests continued of the RD-170 in preparation for the first flights of the Energiya rocket. In November 1985 the engine was test-fired for the first time as part of an Energiya strap-on booster “modular section’’ at NIIkhimmash’s IS-102 test stand. In all, the RD-170/171 underwent fifteen test firings as part of a Blok-A or Zenit first stage at NIIkhimmash. By the time of Energiya’s maiden launch in May 1987, a total of 148 RD-170 engines had undergone 473 test firings totaling 51,845 seconds. By early October 1988, only weeks before the first attempted launch of Energiya-Buran, these numbers had increased to 186 engines, 618 test firings, and 69,579 seconds of accumulated burn time.

Test firings of the RD-170 continued after the two flights of Energiya and were mainly aimed at further improving the engine so that it could be reused on as many as ten Energiya missions, a capability that was demonstrated by 1992. Meanwhile, PO Polyot’s serial production plant in Omsk opened its own test-firing stand at Krutaya Gorka (55 km north of Omsk), carrying out six tests of RD-170 engines beginning on 29 December 1990. The test stand was reported to be the scene of a major explosion on or around 20 November 1991, which probably rendered it useless for further test firings [3].

When the Energiya program was canceled in 1993, a total of 14 flightworthy RD-170 engines had already been installed on Blok-A strap-on boosters awaiting their missions at Baykonur’s Energiya assembly building. In 1996-1997 the engines were removed and shipped back to Energomash to be modified as RD-171 engines for use in the Zenit rocket as part of the Sea Launch program [4].

As the Space Shuttle moved to the foreground as the next big step in NASA’s manned spaceflight program in the late 1960s/early 1970s, Western experts began speculating on the existence of a Soviet equivalent. Few realized that the shuttle effort the Soviet Union was involved in at that time was Spiral, the 9-ton military spaceplane to be launched from the back of a hypersonic aircraft. One person who did get the basic concept right was Peter James, a Pratt & Whitney engineer and intelligence informant, who talked to leading Soviet aviation and space experts during the annual congresses of the International Astronautical Federation and summarized his findings in a controversial 1974 book called Soviet Conquest from Space.

During his private discussions with Soviet officials, James clearly picked up some shreds of information on Spiral. One of the specialists he talked to at the 1969 IAF congress in Argentina was none less than Gennadiy Dementyev, identified in the book as “one of the heads of the Soviet space effort and affiliated with the Moscow Aviation Institute’’. As is now known, Dementyev (the son of the Minister of the Aviation Industry) had indeed worked at the institute, but in 1967 was named Lozino-Lozinskiy’s deputy for the Spiral project at Mikoyan’s space branch in Dubna. In his book, James correctly pointed out that the Soviet Union was working on an air-launched spaceplane which in an initial stage would be launched by an expendable rocket while the design of the carrier aircraft was finalized. However, he grossly overestimated the size of the shuttle vehicle, claiming it would have a payload capacity of 35-45 tons, more than the Space Shuttle. He also got the organizational background completely wrong [2].

Meanwhile, some die-hard armchair analysts of the Soviet space program were doing their own research on Soviet shuttle activities in the best traditions of “space sleuthing”. As early as the mid-1970s a group of Dutch space enthusiasts, having carefully analysed obscure Soviet technical publications and isolated statements from Soviet officials, also came to the conclusion that the Soviet Union was developing an air-launched shuttle system. Unaware of James’ publication, they described the system as follows in one of their articles:

“The Soviet shuttle system, … baptized recently ‘ALBATROS’, seems to be much more advanced than the US type currently under construction. It will possibly be in active duty well ahead [of] its American counterpart. The system consists of… twin recoverable craft, both… delta wing vehicles, and uses the horizontal liftoff principle from specially adapted SST [supersonic transport] runways. The booster-plane is an improved SST type, in size about the Tupolev 144 SST. It is however a much more advanced type, a HST (Hy­personic Transport) using air breathing engines to ride the piggyback orbiter towards 30 km altitude. There the ALBATROS is separated and uses its own system of chemical and electrical engines to propel itself into Earth orbit [3].

Whether by coincidence or not, this was a fairly accurate description of the Spiral system, although few believed them at the time. Like James, the Dutch space sleuths also overestimated the size and capabilities of the shuttle vehicle, but had got the basic concept right. ‘‘Albatros’’ later turned out to be the name of an unrelated two-stage-to-orbit shuttle system to be launched from a hydrofoil that was studied by students at the Bauman technical university in Moscow [4].

Given the dearth of declassified CIA reports on the Soviet space program, it is difficult to say at this stage exactly what was known about Spiral inside the US intelligence community. A 1983 CIA report said a spaceplane effort had begun at the Mikoyan design bureau in 1969 (four years after it actually got underway) [5]. In the few documents that have been released so far, there is no mention of the fact that the spaceplane was eventually supposed to be air-launched, but that doesn’t neces­sarily mean the CIA wasn’t aware of those plans. Since the hypersonic carrier aircraft never got further than the planning stage, any information on it must have been gathered via private conversations or human intelligence.

What the Russians definitely could not conceal from US reconnaissance assets were the test flights flown in support of Spiral, beginning with the BOR-1/2/3 suborbital missions in 1969-1974. What is known for sure is that US intelligence picked up signs in the second half of the 1970s of the test flights of the 105.11 Spiral atmospheric subsonic test bed in Akhtubinsk (the ‘‘Vladimirovka Advanced Weapons and Research Complex’’ or VAWARC as the CIA called it). Those tests were reported in the trade press in early 1978 [6]. However, in a classified assessment of Soviet space capabilities released to authorized persons in August 1980, US intelligence experts wrongly concluded that these had been tests of a delta-wing spaceplane to be orbited by the three-stage version of the Proton rocket, capable of putting 20 tons into low Earth orbit. Although Spiral had been canceled by this time, the small spaceplane was believed to be under development for future military missions such as reconnaissance, satellite inspection and neutralization, although it could also be developed into a crew ferry vehicle to support space station operations.

At the same time, the report linked the construction of a runway and new launch pads at Baykonur’s former N-1 launch complex to a separate effort to build a new family of heavy-lift launch vehicles, capable among other things of orbiting a reusable spacecraft the size of the Space Shuttle Orbiter. This is the first reference in the declassified US intelligence literature to the Energiya-Buran program. The motives for building such a vehicle were believed to include a desire to economize on space launches, particularly in the area of large space station construction, manning, and supply, as well as the general desire to compete with the United States for prestige. The spaceplane was expected to be fielded in the early to mid-1980s, followed by the larger vehicle in the early 1990s [7].

Only hours after the mission the Central Committee of the Communist Party sent the obligatory congratulatory message to the Energiya-Buran team.

“The launching of the Buran craft… and its successful return to Earth open up a qualitatively new stage in the Soviet space research program and substantially extend our opportunities for space exploration. From now on, Soviet cosmo­nautics possesses not only the means of placing large payloads into various orbits, but also the ability to return them to Earth. The use of the new space transportation system in conjunction with expendable carrier rockets and with permanent manned orbital complexes makes it possible to concentrate the prin­cipal efforts and means on those areas of space exploration that will ensure the maximum economic return to the national economy and will advance science towards higher frontiers… The new success of Soviet cosmonautics has once again convincingly demonstrated to the whole world the high level of our home­land’s scientific and technical potential.’’

The message may not have sounded so convincing to the Energiya-Buran officials who had heard the private comments of Mikhail Gorbachov during his visit to the Baykonur cosmodrome in May 1987 (see Chapter 6). Gleb Lozino-Lozinskiy didn’t spare Gorbachov in one of his final interviews many years later:

“ … we already felt that there probably wouldn’t be any more flights… Buran had flown. You’d think that… the General Secretary of the CPSU, responsible for the country, its prestige, should show some interest. But when that General Secretary… was told that Buran had landed, he just said: “OK, fine’’. He displayed absolutely no understanding, interest in the country’s… successes and achievements in the field of technology and science.. .Gorbachov .. .was notable for an exceptional ability to display inability. I later called him, tried to meet him to explain things, but to no avail’’ [58].

The Soviet press generally hailed the flight in a style typical of the pre-glasnost days, although that would gradually change in the following months as the space program in general increasingly became a target for public criticism. However, even amid the initial flush of excitement over the successful completion of the mission, there were voices of dissent, surprisingly from the space community itself. Just days after the flight, Roald Sagdeyev, the head of the Institute of Space Research (IKI) and a science adviser to Gorbachov, termed the Soviet shuttle “an outstanding techno­

logical achievement but a costly mistake.” Sagdeyev, who was visiting the United States with dissident scientist Andrey Sakharov, said: “It went up and it came down. But it had absolutely no scientific value. My personal view is that American experi­ence with the Shuttle indicates that from the point of view of cost efficiency, the shuttle is in deep trouble. It is much simpler and cheaper to fly a payload with any kind of expendable vehicle … We have put too much emphasis on manned flight at the expense of unmanned efforts that produced more scientific information at lower cost” [59].

International reaction to the flight was largely positive, with many observers admiring the pinpoint precision of Buran’s automatic landing system. “[The flight] shows that the Russians’ boldness and ambition is matched by their ingenuity,’’ said Soviet space expert James Oberg in an interview for Time magazine. “It blows us out of our last space-operations monopoly’’ [60].

Inevitably omnipresent in the Western reactions were comments on the similarity of Energiya-Buran to the US Space Shuttle. US specialists generally questioned the official Soviet explanation that the laws of aerodynamics require similar designs, pointing out that American engineers considered several quite distinct designs, including some markedly different wing and fuselage shapes, before settling on the one adopted in the early 1970s. Nicholas Johnson, another respected American observer of the Soviet space program, said:

“The fact that the Soviets picked a design identical to ours can’t be coincidental. There’s no doubt they took advantage of a vast amount of engineering devel­opment that went into ours. I don’t think stealing was necessary. A lot of the information was unclassified and open, if you knew where to look for it’’ [61].

In an editorial only days after the flight, Aviation Week downplayed the significance of the similarity between the two systems, focusing instead on the implications the mission had for America’s place on the international space scene:

“There is validity in the contention by Western observers that much of the technology embodied in the Buran has been gleaned from the data base gener­ated by the U. S.’s development of the space shuttle. But concentrating on that issue misses the point and gives small comfort to U. S. officials concerned with maintaining a position of space leadership. The advanced materials, computers, software, aerodynamics and propulsion in the Soviet shuttle system and ability of the Soviet team to integrate multiple fault-tolerant computers and manage them effectively is something they have never before demonstrated … The USSR has joined the reusable shuttle club and will not be turned back. The Soviets can be expected to aggressively exploit their shuttle’s potential. Major applications they see are to build a large permanently manned space station and then prepare a springboard for a manned mission to Mars… The Buran/ Energiya mission is to be hailed as a success. It also should be taken as another reminder that an aggressive, broadly based space program is an integral

part of the Soviet Union’s national policy. It cannot be considered any less than that by the U. S.’’ [62].

Little did anyone know at the time that Buran was destined to remain on the ground forever.

Currently, five full-scale Buran test articles still reside at various locations in the former Soviet Union, four of them in a fully assembled state. Two vehicles, OK-MT and OK-ML1, remain at the Baykonur cosmodrome. OK-MT is situated in the MZK building together with flight vehicle 2K and is said to be in relatively good condition. The same cannot be said of OK-ML1, which for a long time sat exposed to the elements at the orbiter test-firing stand. It is in a sorry state, with many of its parts having been stripped by visiting tourists. In January 2007 it was parked next to the Baykonur museum on Site 2 of the cosmodrome and there were plans to turn it into an exhibit.

Any plans to ferry the remaining vehicles to Russia or other countries are compounded by the fact that all the remaining Energiya-Buran hardware at Baykonur is now the property of Kazakhstan. Moreover, the mate-demate device needed to lift the orbiters onto the Mriya aircraft near the Yubileynyy runway has not been maintained in an operational state.

Probably the most famous full-scale test article is OK-M, which sits as a tourist attraction in Gorkiy Park on the banks of the Moscow River. The cargo bay has been turned into what looks like the passenger section of an aircraft, with visitors being able to watch images of the Earth projected on screens and being treated to space food. Before entering the vehicle they get a symbolic medical check-up and a certificate clearing them for an imaginary flight in space.

The electrical test model OK-KS remains at the facilities of RKK Energiya in Korolyov, while the partially disassembled test model OK-TVI is in storage at Nllkhimmash near Sergiyev Posad. RKK Energiya has been trying to somehow get rid of OK-KS, which occupies valuable space at its facilities, but to no apparent avail, mainly due to the absence of a presidential edict officially canceling the Energiya-Buran program. However, something may happen with them after all, now that the Russian government has begun allocating at least some funds for dealing with remaining Energiya-Buran hardware [55].

Another offshoot of the Energiya propulsion system is the RD-191, a single-chamber version of the RD-170/171 designed to power Russia’s new Angara family of launch vehicles.

Originally, Angara (named after a Siberian river) was conceived as a heavy launch vehicle to replace the Proton. Its history began with a government decree (nr. 716-53) issued on 15 September 1992 calling for the development of a launch vehicle capable of lifting 24 tons to low orbit and 3.5 tons to geostationary orbit from the Plesetsk cosmodrome in northern Russia. Proton could only fly from Baykonur in Kazakhstan, the future of which was uncertain after the collapse of the USSR. The new launch vehicle was to be built exclusively by Russian enterprises and make maximum use of Energiya-Zenit technology.

Responding to the decree, the Russian Space Agency and the Ministry of Defense, the two organizations that had ordered the vehicle, launched a tender between three design bureaus: NPO Energiya, the Khrunichev Center, and the Makeyev bureau, the latter having specialized for years in sea-launched inter­continental ballistic missiles. Rather than proposing separate projects, NPO Energiya and Makeyev joined forces in January 1994 to design a launch vehicle provisionally called Energiya-3. This had a first stage comprised of three modules each powered by an RD-180 engine, and a second stage with an RD-146 engine, a re-ignitable version of the Zenit second stage’s RD-120.

The Khrunichev vehicle had a first stage employing the RD-174, yet another modification of the RD-170/171, and a second stage using one of the Energiya core stage’s RD-0120 LOX/LH2 engines. Both the first and second stages had suspended propellant tanks, giving the rocket an odd external appearance. For geostationary missions the rocket would have used a LOX/LH2 upper stage. Other plans were to turn the first stage into a reusable flyback booster and eventually to launch the vehicle

from the Svobodnyy cosmodrome in the Russian Far East. Both proposed launch vehicles would have been able to fly from modified Zenit pads.

In September 1994 the Russian Space Agency and the Ministry of Defense selected Khrunichev as the winner of the competition, although development of the second stage was subcontracted to RKK Energiya. The decision was consolidated by another government decree on 26 August 1995, which set the maiden flight of Angara for 2005. However, during the following two years it became apparent that Khrunichev’s design was basically flawed. Among the problems were the rocket’s very low thrust-to-weight ratio (1.09) and the challenges associated with igniting the RD-0120 at altitude, not to mention the fact that the engine’s production line at KBKhA in Voronezh had been closed [74].

Another problem with Khrunichev’s design was that it was primarily geared to replacing the Proton and left little room for building derived launch vehicles. The best Khrunichev had come up with were two rockets called Yenisey and Neva. Yenisey basically was an Angara first stage topped by a Zenit second stage, giving an 18-ton capacity to low orbit, and a 2.5-ton capacity to geostationary orbit with a KVRB cryogenic upper stage. Neva was an all-cryogenic vehicle, using Angara’s second stage as its first stage and the KVRB as second stage, optimized to place 4.1-ton payloads into polar orbit [75]. However, the range of payloads that could be orbited by these boosters was minimal and, moreover, Neva required a dedicated launch pad.

All this was at a time when the Russians realized that they needed a replacement not only for Proton, but also for other venerable 1960s launch vehicles such as the Tsiklon and Kosmos-3M, whose production lines were expected to be closed. The problem could at least temporarily be solved by switching to converted ballistic missiles such as Rokot and Dnepr, declared excess in accordance with international disarmament agreements. However, under those agreements all redundant Russian ICBMs had to be destroyed by 2007.

In 1997 several Russian companies devised strategies to modernize the Russian rocket fleet, aiming to lower costs by relying on modular designs and allay environ­mental concerns by using ecologically clean propellants rather than the toxic storable propellants employed by the old ICBM-derived rockets. In many ways this was a return to the plans for standardized launch vehicles in the early 1970s that had given rise to the Energiya and Zenit families. Ironically, the Energiya family was now dead because of a lack of affordable payloads and the Zenit family had remained restricted to the 11K77 because its design bureau was now situated in independent Ukraine.

In RKK Energiya’s vision the light payload range (1-5 tons) would be covered by rockets known as Kvant and Diana, medium-size payloads (7-15 tons) would con­tinue to be launched by Soyuz-derived rockets and Zenit rockets, and heavy payloads (20-25 tons) would go up on RKK Energiya’s originally planned Angara version. For geostationary missions the Angara would carry a Blok-DM-SL upper stage of the Sea Launch program with an increased propellant load. The company also proposed to launch the same Angara vehicle from Baykonur’s UKSS pad under the name Sodruzhestvo (“Commonwealth”) with equal financial input from Russia, Kazakhstan, and Ukraine. The Kvant rocket would be redesigned to have a first stage with an RD-180 engine and a Blok-DM-SL second stage, thereby paving the way to Angara, much like Zenit had served as a pathfinder for Energiya. Other contenders were the Makeyev design bureau with a family of both land and sea-launched lightweight boosters (Riksha) burning liquid oxygen and methane, the Kompomash corporation, TsNIIMash, the Keldysh Center, and TsNII-50 [76].

Khrunichev also changed its strategy in accordance with the new requirements. In March 1997 the company scrapped plans for its original heavy-lift Angara and decided to turn Angara into a family of launch vehicles accommodating a broad range of payloads. The core element of the Angara family became a so-called Universal Rocket Module (URM) acting as the first stage. Powered by the RD-191, the URM could fly as a single unit or in clusters of three to six. Mounted above it would be one or two stages, depending on the mass of the payload. Propellant combinations considered for these upper stages were nitric acid/UDMH, LOX/kerosene, LOX/methane, and LOX/LH2. Khrunichev retained its earlier idea of turning the first stage into a reusable flyback booster, now called Baykal, in cooperation with NPO Molniya.

The Khrunichev plan seems to have been given the nod in late 1997/early 1998 without much consideration for the other proposals, which was possibly a result of the fact that Khrunichev became subordinate to the Russian Space Agency in 1998. This sparked off angry reactions from RKK Energiya, whose Angara proposal had been turned down in 1994 largely on the basis of the fact that the RD-180 was an unflown engine. However, by now the RD-180 was undergoing successful (US-sponsored) test firings in support of the Atlas program, and it was the RD-191 that was the untested engine.

By late 1998 Khrunichev had more than 10 Angara configurations on the drawing boards, some looking more exotic than others. Payload capacity would have been between 2 to 4 tons to low orbit on the lower end of the payload scale, and between 13 and 24 tons on the heavier end of the payload spectrum, leaving the 7-10 ton niche to the Soyuz family. Geostationary orbit capability would have been between about 1 and 5 tons [77]. However, economic realities soon forced Khruni­chev to scale down its ambitions to just four rockets, two light versions (Angara 1.1 and 1.2) with a single URM and two heavier versions (Angara-A3 and Angara-A5) with three and five URM modules, respectively. Payload mass to low orbit for the first two rockets is 2.0 and 3.7 tons and 14.6 and 24.5 tons for the latter two.

Although the RD-191 is an unflown engine, the idea to build a single-chamber version of the RD-170/171 is not at all new. In the late 1970s/early 1980s Energomash had already done detailed design work on such an engine (the MD-185) for the

first stage of Zenit and Energiya’s strap-ons to safeguard against problems with the RD-170/171 (see Chapter 6). A similar engine (the RD-141) had been considered for the second stage of the 11K37. The RD-191 delivers 196 tons of thrust at sea level and has a specific impulse of 310 s. It features a new turbopump unit driven by a single gas generator and a new system of mixture ratio control. Control of the thrust vector is provided through gimbaling of the engine about two axes.

On 31 December 1998 Khrunichev signed a deal with Energomash for the design, manufacture, and delivery of RD-191 engines for the Angara family. Mock-up versions of the engine were built for full-scale models of Angara 1.1 and

the Baykal flyback booster shown at the Paris Air Show in 1999 and 2001, respec­tively. The RD-191 test-firing program began with a short 5 s test at Energomash’s Khimki facilities on 27 July 2001. About 70 test firings are required to certify the engine for flight [78].

Launch dates for the Angara rockets have continued to slip, partly due to slow progress in the construction of launch facilities at Plesetsk. Although these are located on the same site once intended to support launches of Zenit rockets, they essentially had to be built from scratch. In a plan reminiscent of RKK Energiya’s 1997 Sodruzhestvo proposal, Angara is also expected to be launched from a modified Proton complex at Baykonur called Bayterek (“Poplar”) under a joint venture between Khrunichev and the Kazakh Finance Ministry’s State Property and Privatization Committee. In addition to that, Khrunichev is developing a modified version of Angara’s URM (also carrying the RD-191) that will act as the first stage of a South Korean launch vehicle called KSLV-1. The first Angara is now not expected to fly until after 2010, but whenever it goes up, it will carry with it the legacy of the Energiya-Buran program.