Category Energiya-Buran

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.

While the main focus over the past forty years has been on winged spacecraft launched with conventional rockets or from airplanes, the Russians have never abandoned the idea of eventually fielding a single-stage-to-orbit (SSTO) spaceplane that can take off horizontally like an ordinary aircraft. Although the development of an SSTO system remains a distant dream (even in the West), plenty of research has been done in the field in the past decades.

One of the first Soviet SSTO spaceplanes was put on the drawing board by Yevgeniy S. Shchetinkov in 1966 at the Scientific Research Institute of Thermal Processes (NII TP, the former NII-1 and the later Keldysh Research Center). Shchetinkov, a veteran of the GIRD and RNII rocket research institutes of the 1930s, had formulated ideas for scramjet engines as early as 1957. Using a com­bination of ramjet, scramjet, and liquid-fuel engines, his proposed spaceplane had a take-off mass of between 150 and 250 tons and was capable of placing between 6 and 11 tons into orbit [18].

Meanwhile, even as NASA was still preparing to land the first Apollo astronauts on the Moon, the space agency was drawing up plans for the post-Apollo era. In January 1969 NASA appointed four aerospace companies to study possible configurations for what it called an “Integrated Launch and Re-entry Vehicle’’ (ILRV), what would eventually become the Space Shuttle. As these studies got underway, a Space Task Group (STG) headed by Vice President Spiro Agnew recommended that America embark on a manned flight to Mars and devised three options to achieve this goal, each of which would need the logistical support of a reusable spacecraft shuttling back and forth between Earth and low orbit. Also part of the space infrastructure would be a low-orbiting space station, a space tug, a lunar base, and a nuclear propulsion system for interplanetary missions. The most modest of the three options was to develop only a shuttle and a space station and defer a decision on a manned Mars flight until after 1990.

However, when the STG released its report in September 1969, waning public interest in the space program and the escalating cost of the Vietnam War were about to take their toll on America’s ambitious space plans. NASA’s budget was drastically cut back, dashing any hopes of turning the STG’s plans into reality anytime soon. It turned out that even the cheapest of the three options (requiring $5 billion per year until 1980) cost more than the nation could afford. When President Nixon officially reacted to the STG report in March 1970, all he left standing of the STG plan was a shuttle vehicle “designed so that it will be suitable for a wide range of scientific, defense and commercial uses [and] help us realize important economies in all aspects of our space program.’’

If the Shuttle was going to be turned into a satellite-carrying truck, it would only be economically effective if it achieved an extremely high launch rate and placed all government, commercial, and military payloads into orbit. In other words, it had to replace all existing expendable launch vehicles. Therefore, it was crucial for NASA to gain agreement from the military community to use the Space Shuttle to launch all military and intelligence payloads, which were projected to constitute one-third of all

future space traffic. For the military this was not a bad deal, because they would acquire a launch vehicle built at NASA’s expense. Their only major investment in the Shuttle would be the construction of a launch pad at Vandenberg Air Force Base in California to enable launches of military payloads into polar orbits. At the same time, Defense Department (DoD) requirements also had a very serious impact on the Shuttle’s design.

Until then the favored option within NASA had been to develop a completely reusable vertically launched system consisting of a relatively small spaceplane and a flyback booster, mated either belly-to-belly or piggyback. The flyback booster (either manned or unmanned) would act as the first stage, carrying the shuttle to a significant altitude before separating and returning to the launch site to make a horizontal runway landing. The shuttle would then use its on-board fuel supply to complete the trip to orbit. The preferred design for the spaceplane was a vehicle with stubby straight wings. This was designed to re-enter the Earth’s atmosphere at a high angle of attack, which would reduce frictional heating. It would make only minor hyper­sonic maneuvers and have excellent subsonic glide characteristics.

The Defense Department requirements, first of all, changed the dimensions of the orbiter. The DoD needed an orbiter that could handle payloads up to 18 m long and launch 18 tons into polar orbit from Vandenberg and over 27 tons into a due-east orbit from Cape Canaveral. This was significantly more than what NASA had asked for in its original request for proposals in 1969. Even more significantly, the DoD required a much higher cross-range capability, the ability to maneuver to either side of the vehicle’s ground track during re-entry. The Air Force wanted a cross-range capability of about 2,000 km, which would allow the Shuttle to quickly return to its secure launch site runway at Vandenberg after a single revolution while the Earth rotates to the east under it. However, this requirement dictated a delta-wing vehicle with a much higher hypersonic lift-to-drag ratio as well as a much more robust thermal protection system. This is because most of the cross-range maneuvering is performed at extremely high speeds, exposing large portions of the airframe to the thermal effects of re-entry. Also, the delta-shaped wings entail a much worse per­formance at subsonic speeds, with the orbiter making a very steep descent and coming down at a much higher speed.

The net result was that the orbiter was going to be much bigger and heavier than originally anticipated, making it impossible to retain the spaceplane/flyback booster concept. Instead, the orbiter’s propellant would now have to be carried in an expend­able external fuel tank and the flyback booster was replaced by two solid rocket boosters, which is the Space Shuttle configuration as we know it today. On 5 January 1972 President Nixon gave his final go-ahead for the development of the Space Shuttle, but it would take another two years for the design to be frozen. One of the last changes was the deletion of an air-breathing propulsion system in early 1974 [1].

The new launch vehicle was called RLA-130. While there were still four strap-on boosters with 600-ton RD-123 engines, the three 250-ton thrust RD-0120 engines were now on the “external tank’’ rather than on the orbiter. The overall launch mass was the same as that of the OS-120 (2,380 tons), but the orbiter now weighed just 116.5 tons at launch as compared with 155.35 tons for the OS-120.

Now devoid of main engines, the OK-92 orbiter was to be equipped instead with two kerosene-fueled D-30KP turbojet engines mounted in external pods on either side of the aft fuselage. Widely used on the Ilyushin-62 passenger airliner, these would have to give the orbiter more flexibility in reaching the runway. Also, with a shorter landing roll-out (2.5-3 km vs. 4 km for the OS-120), the vehicle could land on many ordinary runways in the USSR. The engine inlets and outlets would be protected from the vacuum of space and the heat of re-entry by jettisonable covers. The engines were to be activated at an altitude of between 5 and 8 km.

The orbital maneuvering engines and aft reaction control thrusters were now installed in pods adjacent to those housing the D-30KP engines. The nozzles of the forward reaction control thrusters were protected during launch and re-entry by a special cover. As on the OS-120, the propellants to be used by the engines would be hypergolic. The orbital maneuvering engines were to be derived from the 15D619 engine used on the second stage of KB Yuzhnoye’s UR-100 ICBM. The ultimate goal, however, was to replace the toxic propellants by a combination of hydrogen peroxide (H2O2) and kerosene, the latter of which could then be used both by the

D-30KP turbojet engines and the on-orbit propulsion system. For that combination engineers would draw on the experience gained with the RD-510, an H2O2/kerosene engine developed at Energomash for the lunar module of the canceled N-1/L-3M manned lunar project.

OK-92 retained a solid-fuel emergency escape system for early launch aborts, but it now consisted of a single engine installed under the vertical stabilizer. This would be jettisoned 56 seconds into the launch, after which the vehicle would have gained enough speed and altitude to reach the runway with its turbojet engines after an emergency separation from the rocket. In case they were needed in a launch abort, the D-30KP engines could be activated in about 30-50 seconds.

Another feature which set OK-92 apart from the US Orbiter was the use of two remote manipulator arms to deploy payloads from the cargo bay. It was also planned to use the arms in docking operations, pretty much like the Space Shuttle Endeavour used its mechanical arm to dock the Unity module with Zarya during the first Shuttle ISS assembly mission (STS-88) in 1998.

Prior to the maiden orbital mission, the Russians were planning to carry out an extensive series of atmospheric approach and landing tests. In the first stage many on­board systems (such as the propulsion and emergency escape engines, various cabin systems, the remote manipulator arms, etc.) were to be replaced by mock-ups and the vehicle could take off either on its own power or (if its mass was reduced to 60-80 tons) on the back of the An-22 “Antey” aircraft, which would then release it at an altitude of about 2 km. If the mass was reduced to 51-60 tons, the An-22 could also be used to transport the orbiter over a distance of about 2,000 km at an altitude of 2 km. Both for the drop tests and the ferry flights the OK-92’s D-30KP turbojet engines could be used to assist during take-off and the climb to cruise altitude.

For the second stage of the landing tests the OK-92 would be outfitted with most of the systems needed for orbital flight, including the propulsion system and the solid – fuel escape motor. Now too heavy to be carried by the An-22, the OK-92 would fly all the remaining atmospheric test flights on its own power. Plans called for using the combined thrust of the turbojet engines, orbital maneuvering engines, and the solid – fuel motor to take the vehicle to an altitude of 21km and a speed of 1,800 km/h (Mach 1.5) to simulate the final portion of its mission. This was far higher and faster than NASA had been able to do with Enterprise. At this point in time the Russians did not plan a dedicated atmospheric test vehicle, but one that would later be modified into a spaceworthy orbiter. At the time, NASA was planning to do exactly the same with Enterprise, until it was realized in late 1977 that it would be cheaper to turn Structural Test Article STA-099 into the second flight article (what became OV-099 Challenger).

The turbojet engines would also have allowed the OK-92 to fly on its own power to the Baykonur cosmodrome either from the manufacturer or from back-up runways. The range would have been 1,600 km at a cruise altitude of 3 km. However, that could have been increased to 3,000 km by increasing the fuel supply for the engines and using the emergency solid fuel motor as an afterburner on take-off [58].