Category Energiya-Buran

With state orders for RD-170 and RD-171 engines running out, NPO Energomash began looking at international marketing opportunities for its engines in the early 1990s, setting its sights on America in particular. Realizing that the RD-170/171 thrust levels were beyond what was needed on American launch vehicles, the com­pany designed a two-chamber version of the engine called RD-180 that was tailored to the US market and was probably similar to a first-stage engine studied for the 11K55. In October 1992 Pratt & Whitney started working with Energomash to draw American customers to the RD-180 and a tripropellant engine known as the RD-701, and also to advise the Russian company on ways to implement a cost-accounting system [71]. The RD-180 was considered for use on a new two-stage Martin Marietta booster as well as an upgraded version of General Dynamics’ Atlas-II rocket [72].

In 1994 General Dynamics Space Systems was sold to Martin Marietta, which in turn merged with Lockheed in 1995 to become Lockheed Martin. The company continued looking at new engines to power its new Atlas-IIAR rocket (later renamed Atlas III) as well as a new generation of Atlas vehicles (Atlas V) being developed under the Air Porce’s Evolved Expendable Launch Vehicle (EELV) competition. In January 1996 Lockheed Martin’s choice fell on the RD-180, which beat the Aerojet – sponsored NK-33, a Russian engine originally developed for the N-1 Moon rocket,

and a derivative of Rocketdyne’s venerable MA-5A called the MA-5D. Just one nozzle of the RD-180 generates as much thrust as all three MA-5A nozzles combined on the older Atlas configuration.

The RD-180 essentially is an RD-170 “cut in half” with a new, less powerful turbopump driven by a single gas generator. About 75 percent of parts are identical to those of the RD-170. It has a sea-level thrust of 390 tons and a specific impulse of 311 s. The engine has several features that made it attractive to Lockheed Martin. It operates at much higher pressures than most other expendable booster engines, allowing the deep throttling capacity critical to effective engine use. The RD-180 can throttle over a 40-100 percent range, yet it remains flat in specific impulse throughout this range (losing just about a second of Isp), which is very important to fly the engine on both light and heavy-lift launch vehicles. The RD-180’s single-shaft turbine, liquid-oxygen pump, and single-stage propellant pump are all on one shaft, which cuts overall parts count, reduces cost, and translates to excellent reliability. Further­more, adoption of Russian seal and flange technologies virtually eliminated cryogenic system leaks that were accepted as normal on US boosters.

In early 1997 Energomash and Pratt & Whitney expanded their cooperation on the RD-180 into a joint venture called RD Amross LCC to build and market the engine. At the time the RD-180 accounted for 75 percent of Energomash’s business. In June 1997 Lockheed Martin announced it would purchase 101 RD-180 engines from Amross under a contract expected to be worth 1 billion dollars. In a move to allay concerns about relying on Russian technology for placing military and intelli­gence satellites into orbit, Lockheed Martin vowed that the US would set up its own production line at a new Pratt & Whitney facility in West Palm Beach, Florida, but those plans have run into numerous delays.

A prototype version of the RD-180 underwent an initial test firing at Energo­mash’s test facilities in Khimki in November 1996. The first test firing of a full-fledged engine followed in April 1997. Also applicable to the RD-180 were test firings of the RD-173, which had several new features that were incorporated into the RD-180. An RD-180 mated to an Atlas III thrust structure and tank simulator was first test-fired at the Marshall Space Flight Center in Huntsville, Alabama in July 1998. The Atlas III debuted in a spectacular launch from Cape Canaveral on 24 May 2000, success­fully placing into orbit a Eutelsat communications satellite. It was a landmark event in US-Russian space cooperation, very illustrative of the new, post Cold War atmo­sphere. A US rocket that had evolved from an ICBM conceived to level Soviet cities was now powered by a Russian rocket engine that itself had its origins in a program once seen as a crucial part of the military space race.

The Atlas III was retired in 2005 after seven successful missions, clearing the way for the new Atlas V generation. In November 1997 the Air Force had decided to modify its procurement plans for the EELV program, splitting the work between a pair of finalists rather than going for a single winner-take-all award. One of the major reasons given for the redirection was to enhance US space launch competitiveness by keeping two rocket builders in business. The work would now be divided between Lockheed Martin with its Atlas V family and McDonnell Douglas (later Boeing) with its Delta-4 family.

The Atlas V family uses a Common Core Booster (CCB) first stage fitted with an RD-180 engine and flanked by up to five solid rocket boosters. The Centaur second stage is powered by either a single or two RLA-10A-4-2 engines and the payload is protected by either a 4 or 5 m diameter payload fairing. There were also plans for an

Atlas V Heavy featuring three CCBs coupled together, but Lockheed Martin is no longer actively pursuing development of this version.

Given the slightly different flight modes for the medium-lift and heavy-lift Atlas V versions, the RD-180 had to undergo separate certification programs for the two versions, although it is exactly the same engine as flown on the Atlas III. The impressive RD-180 test-firing program was completed in early 2002. Since the first test in 1996, the RD-180 averaged a full flight duration firing every 10 days, encom­passing 135 total development and certification tests in Khimki, comprised of 91 Atlas III class tests, 30 Atlas V Medium class tests, and 14 Atlas V Heavy class tests. All totaled, the RD-180 racked up an impressive 25,449 seconds of development and certification test firing in Khimki alone, equivalent to 110 nominal Atlas V missions. The inaugural flight of the Atlas V took place on 21 August 2002. The RD-180 may also fly on the first stage of a Japanese rocket called Galaxy Express, which is expected to use the first stage of the Atlas III [73].

The requirements stipulated for the new piloted spacecraft in the Federal Space Program were so obviously tailored to RKK Energiya’s Kliper that many wondered if the tender was no more than a formality. However, in January 2006 the Russian Space Agency decided to extend the tender, asking the three companies to bring their proposals in closer agreement with the tender specifications. Finally, in a rather embarrassing move, the agency’s head Anatoliy Perminov announced at the Farnborough air show in England in July 2006 that the tender had been canceled without a winner. Instead, Russia would join forces with ESA to build an Advanced Crew Transportation System (ACTS), with RKK Energiya serving as the prime contractor on the Russian side. This is expected to become a much upgraded version of Soyuz incorporating European technology. An earlier invitation to ESA to join the development of Kliper had been turned down at an ESA ministerial meeting in December 2005.

Despite cancellation of the tender, RKK Energiya is continuing work on Kliper using its own resources. It has the full backing of Nikolay Sevastyanov, who suc­ceeded Yuriy Semyonov as head of RKK Energiya in May 2005. Sevastyanov holds out hope Kliper will eventually receive government funding and be ready to fly in 2015. However, there are signs of growing rifts between RKK Energiya and the Russian Space Agency, which considers Energiya’s plans overly ambitious and way beyond affordable limits. Only time will tell if the differences can be resolved and if Kliper will become the country’s first new piloted space transportation system since Buran.

Although there was significant spaceplane research in the Soviet Union in the 1960s, it was still dwarfed by the effort the country put into its mainstream manned space program, the one that was visible to the outside world. In terms of successes, there were two distinct periods in the Soviet piloted space program in the 1960s. The first part of the decade was marked by amazing triumphs that stunned the whole world. There was the pioneering flight of Yuriy Gagarin in 1961, the first flight into space by a woman (Vostok-6 in 1963), the first three-man flight (Voskhod in 1964), and the first spacewalk (Voskhod-2 in 1965). Then things started going downhill in spec­tacular fashion. First, there was the death in January 1966 of chief designer Sergey Korolyov, the mastermind behind the Soviet Union’s early space triumphs. After a two-year gap in piloted space missions, the maiden manned flight of the Soyuz capsule ended in disaster with the death of cosmonaut Vladimir Komarov in April 1967.

Meanwhile, in August 1964 the Soviet Union had secretly decided to send men to the Moon in response to the Apollo program, kicked off three years earlier by President Kennedy’s announcement in May 1961. The Soviet piloted Moon program was to be carried out in two stages, beginning with manned circumlunar flights (using the L-1 capsules and the Proton rocket) and culminating in manned landings on the lunar surface (using the L-3 complex and the massive N-1 rocket). While the Russians came relatively close to beating America in the circumlunar race, they never stood a chance of upstaging the United States in putting a man on the Moon. Already months behind schedule, the L-3 lunar-landing program was thrown into complete disarray by the catastrophic failure of the first two test flights of the N-1 rocket in February and July 1969.

At the same time, the Soyuz program continued as an independent effort, with a couple of missions flown in 1968 and 1969 (albeit with mixed success). While Soyuz shared many features with the manned lunar craft, the Soyuz program, essentially a

remnant of a canceled circumlunar project of the early 1960s, lacked a clear sense of direction.

Realizing that the ailing Soviet manned space program needed a fresh impetus, a small group of engineers within the Korolyov design bureau started working out plans in mid-1969 for an Earth-orbiting space station (Long-term Orbital Station or DOS) that could be built relatively quickly using available technology and would use Soyuz as a ferry vehicle. By early 1970 they saw their plans approved with the release of a key government decree that would determine the course of the Soviet Union’s piloted space activities for the remainder of the century. After a herculean effort lasting just over one year, the space station, officially dubbed Salyut, rocketed into orbit in April 1971. Unfortunately, the three cosmonauts who boarded the station two months later died during the return to Earth.

Eventually, Sadovskiy’s Department 16, then numbering fewer than 80 people, got down to working out a compromise plan that would satisfy all players. After several weeks of work, they came up with a Space Shuttle type configuration with a side – strapped winged orbiter (OK-92), but with the engines mounted on the “external tank’’ rather than on the orbiter itself. This turned the external tank and the strap-on boosters into a universal launch vehicle capable of flying not only the orbiter, but other payloads as well. Moreover, the number of strap-ons could be varied to match the required payload. On the one hand, the plan made it possible to build an orbiter very similar to the American one (and thereby benefit from American R&D) and, on the other hand, it allowed Glushko to retain his beloved family of launch vehicles.

The report prepared by Sadovskiy’s team was called “Reusable Space System With The Orbital Ship OK-92’’ and contained a comparative analysis with the OS – 120 and MTKVP. Before being sent to Ustinov, it needed to be endorsed by Glushko. Even though the new design went a long way to accommodate his wishes, Glushko realized his signature would probably be the death warrant for his lunar program. Finally, Burdakov was able to talk him around, arguing among other things that Glushko would still go down in history as the man having built the most powerful rocket engine in the world. On 9 January 1976 Glushko signed the report, albeit with mixed feelings. He even called it the “Bloody Sunday” of Soviet cosmonautics, referring to an incident where unarmed, peaceful demonstrators marching to present a petition to Tsar Nicholas II were gunned down by Imperial guards in St. Petersburg on 9 January 1905, exactly 71 years earlier [56].

Perhaps another reason Glushko came around was that the new plan enabled him to deal one final deadly blow to the N-1. Even though work on the N-1 had been suspended in 1974, the project had not yet been officially terminated. Boris Doro – feyev, the chief designer of the N-1, had even prepared an address to the 25th Congress of the Soviet Communist Party (to be held in February 1976) calling for the N-1 program to be resurrected. With the most likely payload for the N-1 now being a shuttle-type vehicle, the very same arguments against mounting a winged orbiter on top of the RLA could now be used against the N-1 as well [57]. Later the Russians would justifiably describe the absence of main engines on the orbiter as one of their system’s main advantages, although they rarely or never pointed out that this design had not been a foregone conclusion from the beginning.

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].