Category Energiya-Buran

Component tests

One of the main motives for the choice of a four-chamber rather than a single­chamber LOX/kerosene engine in 1973 was the possibility to test major components of the engine (primarily the combustion chamber) individually and only later to assemble them for test firings of the complete engine. This followed from the negative experience with the single-chamber 640-ton thrust hypergolic RD-270 engine for Chelomey’s UR-700 rocket, where engineers had moved to all-up tests straightaway. All the 27 test firings carried out in 1967-1969 had ended in some kind of failure before work on the engine was discontinued.

The component tests were conducted between 1974 and 1980 using test models known as “oxygen installations” (UK). Most of these were built on the basis of blueprints and components developed in the early 1970s for the RD-268, a 100-ton thrust engine burning unsymmetrical dimethyl hydrazine (UDMH) and nitrogen tetroxide (N2O4). This was possible because UDMH/N2O4 engines use virtually the same ratio of propellants as LOX/kerosene engines. It did require the use of new materials compatible with LOX/kerosene and modifications to two test firing stands of Energomash on the banks of the Khimka river in the northwest outskirts of Moscow. These were completed in the first eight months of 1974.

The first two of these test models (1UK and 2UK) were essentially 100-ton thrust experimental model engines to test various aspects of the RD-170, such as the ignition sequence, mixing of the propellants in the combustion chamber and gas generator, cooling of the combustion chamber, and the use of reusable materials. A modified version known as 1UKS burned recycled oxidizer gas produced in a gas generator, as was the case for the RD-170. Between August 1974 and November 1977 as many as 346 test firings of these three types of engines were conducted lasting a total of 19,658 seconds.

The next series of tests involved an installation called 3UK, designed to test the RD-170’s gas generator. This consisted of a full-size gas generator, two turbopumps, and a mock-up combustion chamber, making it possible to simulate the pressure, propellant expenditure, and temperature in the gas generator at levels between 30 and 80 percent of nominal values. The tests were conducted between June 1976 and September 1978. A total of 77 3UK installations underwent 132 test firings lasting a total of 5,193 seconds. About 60 mixing heads were tested, with two being chosen for test firings of complete RD-170 engines.

Also built were experimental engines called 2UKS that closely imitated the operating conditions of the RD-170’s combustion chamber, but inherited their turbopumps from earlier designs. Therefore, the chamber developed only 80 percent of the nominal thrust at a pressure of 200 rather than 250 atmospheres. Also tested was the gimbaling system and several of the engine’s automatic systems. A total of 42 2UKS engines accumulated about 6,000 seconds of burn time in 68 tests from May 1977 until June 1978. Interestingly, the 2UKS served as the basis for the development of the 85-ton thrust RD-120, which would later power the second stage of the Zenit rocket.

Finally, Energomash engineers built the 6UK, which essentially was a real RD-170 without a combustion chamber, the main purpose being to test the turbopump assembly. The installation underwent 31 tests between June 1978 and December 1980. The tests revealed that the turbopump was susceptible to burn – throughs and vibrations. Although as many as 23 6UK installations were used, they accumulated just 280 seconds of testing time. Since the 6UK was nearly as expensive as a complete RD-170/171, the test program was limited and the problems with the turbopump assembly were not debugged by the time the full-scale RD-170 test firings got underway. Therefore, the 6UK was much less effective in paving the way to those test firings than the other UK installations, setting the stage for a major crisis in the Energiya program in the early 1980s.

Flight control and соттипісагіо^

Buran’s mission was controlled from the Mission Control Centre (TsUP) in Kalinin­grad near Moscow, the same facility from where Soviet manned space missions had been monitored ever since the joint US-Soviet Apollo-Soyuz mission in 1975. For the Buran mission a new big control room with modernized computer systems was inaugurated. It had the same layout as the neighboring space station control room, with several rows of consoles and a “balcony” where invited guests and media representatives could follow events. Later the Buran control room was modified for controlling the Russian segment of the International Space Station, while the Mir control room was closed down after the space station’s re-entry in 2001. Flight

Four Soviet tracking ships {Belyayev, Volkov, Patsayev, Dobrovolskiy) moored side by side in Leningrad (source: Simon Vaughan).

director for the Buran mission was V. G. Kravets, although overall supervision was in the hands of former cosmonaut Valeriy Ryumin, who also served as flight director for Mir at the time. Working in conjunction with TsUP during the approach and landing phase was the command and control building (OKPD), located right next to the Yubileynyy runway at Baykonur.

TsUP received and relayed information via an elaborate communication network consisting of six ground stations on Soviet territory, four vessels of the Soviet space communications fleet, and several communications satellites in geostationary and highly elliptical orbits. Combined, these facilities provided about 40 minutes of coverage during a single 90-minute orbit.

The ground stations, part of the so-called Command and Measurement Complex (KIK), were situated in Yevpatoriya (Crimea), Shcholkovo (near Moscow), Dzhusaly (near Baykonur), Ulan-Ude, Ussuriysk, and Yelizovo (near Petrapavlovsk – Kamchatskiy). All received broadband information (television and telemetry) from Buran and relayed that real-time to TsUP via Molniya-1 satellites and/or ground lines.

The communication vessels were the Kosmonavt Georgiy Dobrovolskiy and the Marshal Nedelin in the South Pacific and the Kosmonavt Vladislav Volkov and Kosmonavt Pavel Belyayev in the South Atlantic.

The Dobrovolskiy had moved to the South Pacific (45° southern latitude, 133° western longitude) from its usual location in the South Atlantic. Just like the KIK ground stations, it relayed broadband information from Buran real-time to TsUP. The signal traveled more than 120,000 km to reach Mission Control. First, the received data were relayed from the Dobrovolskiy to the geostationary Gorizont-6 satellite, which had been relocated from 140°E to 190°E between July and September in support of the mission. From Gorizont the data went to a ground station of the Orbita network in Petropavlovsk-Kamchatskiy, from there to the neighboring KIK station in Yelizovo, subsequently to an orbiting Molniya satellite, and from there to a station near Moscow, which finally transmitted the data to TsUP.

The Nedelin had left the port of Petropavlovsk-Kamchatskiy on 5 October, reaching its final location (same coordinates as the Dobrovolskiy) on 25 October. It served in a back-up role to the Dobrovolskiy, being capable of receiving only telemetry. The telemetry was processed on board and then relayed to the Raduga – 16 communications satellite, stationed at 190°E right next to Gorizont-6. From there it went to the ground station in Petropavlovsk-Kamchatskiy, which relayed it to TsUP via ground lines.

Just like the Nedelin, the Volkov (5° northern latitude, 30° western longitude) and the Belyayev (16° northern latitude, 21° western longtitude) received only telemetry from Buran, relaying that to TsUP via Raduga satellites.

A crucial link in the network was Kosmos-1897, the second satellite in the Luch/ Altair series, the Soviet equivalent of the US Tracking Data and Relay Satellites. After its launch in November 1986 the satellite had been stationed at 95°E to support Mir operations, but on 26 July 1988 it began moving westward in preparation for the Buran launch, reaching its ultimate destination of 12°E on 26 August. Its footprint stretched from the middle of the Atlantic Ocean to the central Soviet Union. Unlike the Molniya, Raduga, and Gorizont satellites, it was used for direct two-way com­munications between TsUP and Buran via a station near Moscow. The satellite had three antennas, one for the link with the ground and two for direct line-of-sight communications with Buran (one in the centimeter waveband, the other in the decimeter waveband). However, the centimeter waveband system, mainly needed for television, was not activated for the mission, because Buran was not equipped with parabolic narrow-beam ONA antennas. Television images from a camera installed in the cockpit were relayed directly to ground stations when the vehicle passed over Soviet territory. Although only one Luch/Altair was available during Buran’s mission, plans were to deploy two more for 100 percent coverage of future Buran flights [50].

11K77/Zenit

The final version of the 11K77 was approved by a government decree released on 16 March 1976, which set the maiden launch for the second quarter of 1979.

Zenit on the pad at Baykonur. Crew access tower is still in place (source: Russian Space Agency).

However, the project soon ran into substantial delays, mainly due to development problems with the RD-170/171 engines, highlighted by the explosion of a Zenit first stage at the test stand of NHkhimmash in June 1982. The switch to the single-chamber MD-185 engines considered for Energiya was also weighed for Zenit. Eventually, Zenit made its maiden flight on 13 April 1985, almost six years later than originally planned (see Chapter 6).

Original specifications for the 11K77 were to launch payloads into orbits with inclinations between 46° and 98° from both Baykonur and Plesetsk. The Zenit used highly automated launch facilities developed by the Design Bureau of Transport Machine Building (KBTM). These enabled several rockets to be placed on stand­by and be launched in quick succession. The idea was that the Zenit could swiftly replenish constellations of military satellites in case of an impending conflict or if some of them were knocked out by the enemy. Two launch pads were built at Baykonur. Construction of a Zenit pad at Plesetsk got underway in 1986, but the work was suspended in 1994 and the pad is being rebuilt for the Angara rocket family.

The vast majority of Zenit launches have carried KB Yuzhnoye’s Tselina-2 electronic intelligence satellites, placed into 850 km circular orbits inclined 71° to the equator. Actually, the Tselina-2 satellites are far underweight for Zenit, having been originally developed for launch by the lighter Tsiklon-3 rocket and then reoriented to Zenit because of slight increases in dimensions and mass. This was also the case for the Resurs-O1 and Meteor-3M satellites, originally built for launch by the Soyuz and Tsiklon-3 rockets. Most of the payloads really tailored for Zenit never flew as a result of the break-up of the Soviet Union in 1991, which not only led to a major economic crisis but also turned Zenit into a Ukrainian booster. Exceptions were two heavy photoreconnaissance satellites launched in 1994 and 2000 and the Okean-O ocean-monitoring satellite orbited in 1999.

From the outset Zenit was also developed as a man-rated launch vehicle with the necessary built-in redundancy and safety features. In the late 1980s NPO Energiya designed a Zenit-launched vehicle called Zarya (“Dawn”), which outwardly re­sembled an enlarged Soyuz descent capsule. A relic of those plans is a crew access tower still in place at the Baykonur Zenit pad. Zenit was also supposed to launch a variety of cargo ships and modules to Mir-2 and later to the International Space Station, but those plans were abandoned in 1996.

Compounding the problems for Zenit were three back-to-back launch failures that the rocket suffered in the 1990-1992 timeframe. The first of these resulted in the rocket crashing back seconds after lift-off, completely devastating one of the two Baykonur Zenit pads, which still lies in ruins today. But, while the end of the Cold War spelled bad news for Zenit as a domestic launch vehicle, it opened up new frontiers for its use in international programs. The first such opportunity arose in 1989, when Glavkosmos signed a deal to launch Zenits with Blok-DM upper stages from Cape York in Australia. Located on the east coast of Australia’s northernmost peninsula just 12 degrees south of the equator, Cape York was ideal for due east launches over the Pacific Ocean to place communications satellites into geostationary orbits.

Zenit-3SL lifts off from its ocean launch pad (source: Sea Launch).

A three-stage version of the 11K77 had already been envisaged for Soviet domes­tic missions by the original March 1976 government decree on Zenit. Although the Blok-DM had been considered from the outset, KB Yuzhnoye had preferred an upper stage with storable propellants (nitric acid and dimethyl hydrazine) plus an additional solid-fuel apogee kick motor, together capable of placing 1.3-ton payloads into geostationary orbit from Baykonur (compared with 1 ton for the Blok-DM). However, the use of the toxic storable propellants was considered unacceptable for launches from Australian territory, leaving Yuzhnoye no choice but to revert to NPO Energiya’s Blok-DM. Eventually, the Cape York plan fell through because of a lack of investor support.

The big break for the Zenit came in May 1995 with the official establishment of Sea Launch, a joint venture between KB Yuzhnoye, RKK Energiya, Boeing, and Kvaerner to launch three-stage Zenit rockets (Zenit-3SL) with Blok-DM upper stages on commercial satellite deployment missions from a converted Norwegian oil rig near the equator. Initial studies of sea-launched versions of Energiya, Energiya-M, and Zenit had been conducted at NPO Energiya in November 1991-December 1992 because of uncertainty over the future use of the Baykonur cosmodrome and rocket stage impact zones in independent Kazakhstan. Realizing that such a venture would require foreign investors, NPO Energiya officials pitched the idea of a sea-launched Zenit or Energiya-M to Boeing during a visit to the company’s Seattle headquarters in March 1993, with the final choice falling on Zenit in July 1993. Unknown to most of the parties involved (even Energiya), KB Yuzhnoye itself had studied sea-launched versions of Zenit together with KBTM in 1976-1980 under a research program known as Plavuchest (“Buoyancy’’). This would have seen the use of two catamaran-type vehicles, one acting as a launch pad and the other as a command center and storage facility for as many as five Zenit rockets with hypergolic upper stages. Many of the ideas worked out under Plavuchest were later incorporated into Sea Launch.

Sea Launch saw its inaugural mission on 27 March 1999 and has since averaged three launches per year, securing a solid place in the international commercial launch market. The company did suffer a significant setback on 31 January 2007, when one of its rockets exploded during lift-off. Although the launch platform escaped rela­tively unscathed, the commercial implications of this accident are as of yet unclear.

Significant differences between the heritage Zenit and the Sea Launch version were a new navigation system, a next-generation flight computer, and increased performance by mass reductions. The propulsion system remained essentially unchanged. Originally, the hope was to use an improved first-stage engine called RD-173 on which Energomash had begun work in the second half of the 1980s. This engine delivered 5 percent more thrust than the RD-171, had an improved turbo­pump assembly, and a modernized guidance and control system. Experimental versions of the engine underwent static test firings between 1990 and 1996, but further testing was suspended for financial reasons.

With the production line for the standard RD-171 closed due to a lack of state orders, Energomash had no other option but to modify existing RD-170 Energiya engines for use in the Sea Launch program. In 1996-1997 a total of fourteen RD-170 engines were “cannibalized” from mothballed Energiya strap-on boosters and shipped back to Energomash for modification. This batch was enough to ensure several years of Sea Launch operations, but eventually Energomash returned to its RD-173 plans. The modified engine, now redesignated RD-171M, has the same thrust as the RD-171, but is 200 kg lighter and has an improved guidance and control system. Testing started in 2004 and the engine made its debut in February 2006. In May 2004 Sea Launch also introduced a slightly improved RD-120 engine for the second stage (93 tons of thrust vs. 85 tons for the earlier version). Further perform­ance improvements may be achieved by adding suspended propellant tanks to the first stage.

In late 2003 the Sea Launch Board of Directors resolved to go forward with plans to offer launch services from Baykonur in Kazakhstan, in addition to its sea-based launches at the equator. An earlier attempt by Yuzhnoye to commercialize the two-stage Zenit from Baykonur had ended with an embarrassing launch failure in 1998 in which 12 Globalstar satellites came tumbling back to Earth minutes after lift­off. The new offering, Land Launch, is based on the collaboration of the Sea Launch Company and Space International Services (SIS) of Russia to meet the launch needs of commercial customers with medium-weight satellites. The Land Launch Zenits will have the same modifications as the Sea Launch version and can fly in a two-stage configuration for launches to low and elliptical orbits and with three stages to geostationary orbits [68].

Orbiter names and mission designators

The name Buran was first publicly applied to the orbiter individually when the TASS news agency announced the launch date for the first mission on 23 October 1988. Actually, the name originally painted on the first flight vehicle had been “Baykal” (after the famous Siberian lake), but this was later erased. Strictly speaking, Buran had now become the name of the vehicle that made the one and only Soviet shuttle flight on 15 November 1988, placing it on an equal footing with NASA’s Shuttle Orbiter names Enterprise, Columbia, Challenger, Discovery, Atlantis, and Endeavour. However, since Buran was the only vehicle ever flown, the name later also began to be used for Soviet orbiters in general, as it will be in this book.

It is not known what official names the other vehicles would have been given had they ever flown. The only other ship that came close to flying was sometimes referred to in the press as “Buran-2’’, but it is unclear if this would have become its official name. A persistent myth is that it was called Ptichka (“Birdie”), which actually was a general nickname for Soviet orbiters that somehow got misinterpreted by Western journalists as being the name of the second orbiter. There is some speculation that it was to be dubbed Burya (“Storm”), continuing a tradition of naming orbiters and some heavy-lift launch vehicles and their upper stages after violent natural phenom­ena. Burya, incidentally, had also been the name of the Lavochkin bureau’s cruise missile that won the competition from Myasishchev’s Buran back in the 1950s. Presumably, the Russians would have given this matter serious thought only if the second orbiter had entered final launch preparations, which it never did. No name was ever painted on this vehicle and therefore it can be said that it was never officially named.

The individual vehicles did have designators comparable with the OV designators of the US Shuttle Orbiters (OV-099, 101, 102, 103, 104, 105). Buran was 1K, the second orbiter was 2K, the third one 3K, etc. These designators also appeared in the mission designations. The first flight of orbiter 1K was 1K1, the (planned) first flight of orbiter 2K was 2K1, etc. In documentation these numbers were also used to refer to the vehicles themselves, so “vehicle 1K1’’ would be “flight vehicle 1 as configured for its first mission’’. Some Western publications claimed the first flight was desig­nated “VKK-1”, but this is not true. VKK (Vozduzhno-Kosmicheskiy Korabl) literally means “aerospace ship’’, a general term for winged spacecraft, although it is most often used for single-stage-to-orbit spaceplanes. Within NPO Molniya the airframes of the flight articles had designators such as 1.01, 1.02 (for the first two orbiters) and 2.01 (for the third orbiter).

Even though the word “Buran” has been used to refer to different things at different times and the name “Energiya” was not introduced until 1987, for the sake of clarity the two names will be used further in this book to refer to the orbiter and the rocket, respectively, irrespective of when the events discussed took place.

COMMUNICATIONS

Buran’s communication systems performed the following functions:

– two-way voice communications between the orbiter and Mission Control and between the orbiter and other spacecraft;

– intercom between crew members inside the vehicle and between crew mem­bers inside and outside the vehicle;

– relay to the ground of television images;

– relay to the ground of telemetry about the crew’s health, condition of on­board systems, payload-related activities;

– trajectory measurements to determine the vehicle’s exact orbital parameters;

– interaction between ground-based and on-board computers.

There were three independent radio systems, operating in three different wavebands (roughly equivalent to the Space Shuttle’s P-band, S-band, and Ku-band commun­ication systems):

– Meter waveband (VHF): for direct line-of-sight communications with ground stations, tracking ships, and the landing facility, and also for inter­com. This system used omnidirectional antennas.

– Decimeter waveband (UHF): for communications with ground stations and tracking ships either directly or through geostationary relay satellites. Equipped with three transceivers, this system used two omnidirectional an­tennas and five active-phased array antennas.

– Centimeter waveband (SHF): solely for communications through geo­stationary relay satellites using two parabolic narrow-beam antennas. One of these (ONA-I) was mounted on the aft wall of the payload bay, covering the upper hemisphere, and the other (ONA-II) was located in a well on the underside of the aft fuselage, covering the lower hemisphere. ONA-I could be moved off-axis so that its view to the geostationary satellite was not blocked by the vehicle’s vertical stabilizer. Depending on the mission objec­tives and the vehicle’s orientation, the antennas could be used either together or individually. Both antennas could only be deployed in orbit and had to be stowed for a safe re-entry. Therefore, they could be pyrotechnically jet­tisoned if something went wrong during the stowage process. The ONA antennas performed the same role as the Shuttle’s Ku-band antenna, the major difference being that the Shuttle has just one such antenna installed on the starboard side of the payload bay that covers both hemispheres. The ONA antennas were not installed on Buran’s single mission in November 1988.

The data relay satellites intended for use by Buran were the Luch/Altair satellites, approved by the same February 1976 government decree that had given the go-ahead for the Energiya-Buran program. The equivalent of NASA’s Tracking Data and Relay Satellites (TDRS), these were 2.4-ton three-axis stabilized satellites designed to relay communications from and to both Buran and the Mir space station and also to provide mobile fleet communications for the Soviet Navy. They were developed by the Scientific Production Association of Applied Mechanics (NPO PM) near the Siberian city of Krasnoyarsk. Five were launched between October 1985 and October 1995.

Luch/Altair satellite (source: Novosti kosmonavtiki).

Buran’s communication systems were developed by the Moscow-based organ­ization NPO Radiopribor (currently named Russian Scientific Research Institute of Space Equipment Building or RNII KP). Headed throughout the Buran years by Leonid I. Gusev, this organization had a virtual monopoly in developing commun­ication systems for Soviet spacecraft [25].

The landing complex (PK OK)

Very early on in the program a decision was made to build a runway at the Baykonur cosmodrome not only to receive Buran at the end of its missions, but also to deliver Buran and elements of the Energiya rocket to the cosmodrome by the VM-T Atlant and eventually Mriya. NPO Molniya was assigned as prime contractor for the construction of the runway by a party/government decree on 21 November 1977.

Baykonur has had an aerodrome (“Krayniy”) since the early days of its existence, but this is situated close to the city of Leninsk, many dozens of kilometers to the south of the launch facilities, and was therefore not suited for this role. Requirements for the location of the new runway were that it had to be outside the “blast zone” of the Energiya pads and be capable of receiving Buran from either side, both during nominal missions and in launch emergencies. The new facility (called PK OK or 11P72) was eventually built some 6.5 km to the northwest of the UKSS complex and 11 km to the northwest of the Raskat complex.

The central part of the landing complex was a 4.5 km long and 84 m wide runway called Yubileynyy (“Jubilee”), capable not only of receiving Buran, but also planes with a take-off mass of up to 650 tons. The surface layer was made of reinforced concrete with a thickness varying between 26 and 32 cm above an 18 to 22 cm sand/ cement ground layer. This concrete, which was about 1.5 to 2 times stronger than the type used on ordinary runways, was produced in six factories located at a consider­able distance from the runway. This created serious transportation problems since the concrete could remain in liquid state for only one and a half hours before being poured onto the runway. The surface had to be extremely flat, with deviations of no more than 3 mm over a 3 m stretch (compared with 10 mm on ordinary runways). To achieve this, the complete 378,000 m surface of the runway had to be ground like parquet floor with special milling machines.

The Buran landing complex: 1, Yubileynyy runway; 2, asphalt stretches; 3, off-loading area; 4, Buran detanking area; 5, main road linking landing complex with other facilities; 6, railway; 7, command and control building (OKPD); 8, airplane parking platform (source: Dennis Hassfeld).

At either end of the runway was a 500 m long and 90 m wide stretch of asphalt to give Buran more leeway during emergency landings. Running parallel to the main runway at a distance of some 50 m was a 4.5 km long and 100 m wide dirt runway apparently intended for emergency landings by planes, with no role in the Buran program.

Adjacent to the runway were several facilities:

– A platform to drain liquid oxygen, gaseous oxygen, and liquid hydrogen from Buran’s fuel cells and the ODU propulsion system.

– A platform to off-load Buran and elements of the Energiya rocket from their carrier aircraft. This has two mate-demate devices called PKU-50 and PUA-100 capable of handling payloads of 50 and 100 tons, respectively.

Buran being installed atop Mriya using the PUA-100 mate-demate device (source: Sergey Grachov).

– A “waiting platform” for vehicles needed to service Buran after landing.

– A parking platform for airplanes.

– An airplane-servicing area.

Also located in the vicinity of the runway was the ground segment of the Vympel navigational aid system (Vympel-N). This included six transponders for the RDS system (only three of which were required for landing), one beacon for the RSBN system, four beacons for the RMS microwave landing system, and a set of radars.

The nerve center of the landing complex was a six-story high command and control building (OKPD) that acted as a control center for the landing phase, work­ing in conjunction with the TsUP Mission Control Center near Moscow. The build­ing had one big control room for Buran and another for ordinary air traffic control tasks [16].

BURAN PROPULSION SYSTEM AND VSU TESTING

Testing of Buran’s ODU propulsion system was the prime responsibility of the so-called Primorskiy Branch of NPO Energiya in the Leningrad region on the shores of the Gulf of Finland. This was set up in 1958 as a branch of Glushko’s OKB-456, mainly to test engines with exotic propellants such as the RD-301 fluorine/ ammonia engine destined for a Proton upper stage. When OKB-456’s successor KB Energomash merged with TsKBEM in 1974 to form NPO Energiya, the Primorskiy Branch became part of the new conglomerate and remained subordinate to it even after Energomash regained its independence in 1990. Its first assignment as part of NPO Energiya was to test the RD-120 engine for the second stage of Zenit. The old RD-301 test stand was refurbished for a series of horizontal test firings of 11D58M engines for the Proton rocket’s Blok-D upper stage in 1978­1982, which were probably seen as precursors to similar tests with the Orbital Maneuvering Engines (DOM or 17D12) for Buran. Between May 1985 and Septem­ber 1988 six 17D12 engines underwent 114 horizontal test firings lasting a total of 22,311 seconds.

Meanwhile, in 1981 construction had begun of a new vertical test stand called V-1 to test complete ODU engine units called EU-597, containing not just the 17D12 engines, but also thrusters and verniers. The first such ODU unit (nr. 10S) began testing in June 1986 but was destroyed in a fire in February 1987, seriously damaging the test stand. V-1 was refurbished for a series of tests with a new unit (nr. 12S) between September 1987 and April 1988 that underwent the complete ODU firing program planned for the first Buran mission. Those tests uncovered a problem that would delay the Buran flight for several months (see Chapter 7). More tests were conducted with unit nr. 31L between June and December 1988 and unit nr. 11S between January 1991 and March 1993. After cancellation of the Energiya-Buran program the unit was mothballed and eventually removed from the test stand. The 17D15 thrusters and 17D16 verniers apparently also underwent individual tests at Nllkhimmash near Zagorsk. Test firings of the ODU integrated in Buran were conducted at Baykonur’s test-firing platform [14].

The Auxiliary Power Units (VSU) underwent a test program at the IS-104 and IS-105 test stands of Nllkhimmash, which included simulated hydrazine leaks to test the fire suppression system. The VSU hydrazine tank was put to the test in simulated weightless conditions aboard an Ilyushin-76 aircraft and also at various ^-levels at Star City’s TsF-18 centrifuge. The VSU test program culminated in the units being installed on Buran and activated at the Buran test-firing stand at Baykonur.

Building Mir-2

By mid-1991 the 2K1 mission had slipped to 1992 from its original launch date in the first quarter of 1991. Beyond that Buran was now scheduled to take part in the assembly and operation of the Mir-2 complex, where the emphasis would be on the industrial production of ultra-pure medicines and semiconductor materials and also on remote sensing. The plans were presented in detail by Yuriy Semyonov at the congress of the International Astronautical Federation in Montreal in October 1991.

First, the 2K orbiter would go up again in 1993 on an unmanned solo flight (2K2) to test some of the biotechnological installations to be flown under the Mir-2 pro­gram. Then in 1994 the 1K vehicle would fly the first manned mission (1K2) as part of a plan sometimes light-heartedly referred to as “Mir-1.5”, in which Mir would gradually be replaced in orbit by Mir-2. After the launch of the Mir-2 core module by a Proton rocket, Buran would rendezvous with the module, grab it with its two remote manipulator arms, and dock it to a bridge in the cargo bay. Buran would then

1K2 mission as planned in late 1991: 1, Buran picks up Mir-2 core module; 2, Buran docks with Mir; 3, Buran mechanical arm transfers Mir-2 core module to Mir lateral docking port (source: Yuriy Semyonov).

link up with a small docking module on Mir’s multiple docking adapter and again use its manipulator arms to transfer the Mir-2 core module to a lateral docking on Mir previously occupied by the Spektr module. The two modules would remain docked for about two years. After the transfer of the Priroda Earth resources module to the Mir-2 core, Mir and its remaining add-on modules would then have been undocked and discarded, setting the stage for the four-year assembly of the Mir-2 complex (1996-2000).

Before that, in 1995, vehicle 2K would be launched on another autonomous flight (2K3) to test a biotechnological module called 37KBT, based on the original 37KB instrumentation modules. With the emphasis having shifted from fundamental scientific research to biotechnological production, the original plans for the 37KBI scientific add-on modules had been scrapped in late 1989. Buran would now regularly fly two biotechnological modules (37KBT nr. 1 and nr. 2), carrying one up and bringing the other down.

Between 1996 and 2000 there would be two missions annually, one using vehicle 2K to swap out the 37KBT biotechnological modules (2K4, 2K5, 2K6, 2K7, and 2K8) and another using the 1K orbiter for assembly and logistics missions (1K3,1K4, 1K5, 1K6, 1K7). Planned for addition to Mir-2 was a 37KBE “power module’’ equipped with extra solar panels. Further Buran missions would have been required to add a large 85 m truss structure to Mir-2 and outfit it with solar arrays, large radiators, and an array of scientific instruments [30].

The “Mir 1.5’’ plan was dropped in 1992, when it was decided that Mir-2 would

Build-up of Mir-2 using Buran orbiters (source: Yuriy Semyonov).

only be launched after Mir had outlived its usefulness. This would also allow the new station to be placed into a higher inclination orbit (65° vs. 51.6° for Mir) for better remote-sensing coverage. At this point the big Buran-launched 37KB-type modules were abandoned in favor of smaller modules based on the Zenit-launched Progress – M2 cargo ship. The new Mir-2 concept was approved by the Council of Chief Designers in November 1992. Although it left open the option of launching the add-on modules and the station’s truss structure with Buran, Zenit was clearly the preferred option. By the time Mir-2 was merged with Freedom to become the Inter­national Space Station in late 1993, work on Buran had been suspended.

NPO MOLNIYA’S MAKS

Even as the newly created NPO Molniya got down to Buran development in 1976, the Mikoyan bureau contingent in the organization seemingly had a hard time parting with the air-launched Spiral concept. In fact, one NPO Molniya veteran recalls that

Lozino-Lozinskiy was never overly enthusiastic about Buran, which had been forced upon him from above, and that his real passion remained with air-launched systems [3]. Realizing that one of the major drawbacks of Spiral had been the need to develop a futuristic hypersonic aircraft, the Mikoyan designers began drawing up plans for spaceplanes launched from existing subsonic transport planes. The aim was to expand their missions beyond military reconnaissance and offensive operations to satellite deployment/retrieval and space station support. Unlike Buran, such space – planes would be suited to launch payloads usually orbited by expendable launch vehicles and had many other advantages such as quicker turnaround, more launch flexibility, and a wider range of attainable orbits. The new air-launched concept benefited heavily from experience gained in the Spiral, BOR, and Buran programs.

PRELIMINARY STUDIES

Meanwhile, six Soviet military and civilian research institutes were tasked with performing a study of the Soviet Union’s future space transportation needs to help determine the need for a response to the Space Shuttle. These were TsNIIMash and NIITP (the Scientific Research Institute for Thermal Processes, the current Keldysh Research Centre) under MOM, TsAGI (the Central Aerohydrodynamics Institute) under MAP, TsNII-30 and TsNII-50 under the Ministry of Defense, and IKI (the Institute of Space Studies) under the Academy of Sciences. TsNIIMash was given the lead role.

Actually, the studies centered not solely on shuttles, but on a wide array of expendable and reusable launch vehicles that would provide the most economical access to space in the future. They also extended to various reusable space tugs and expendable upper stages with either liquid or nuclear rocket engines for interorbital maneuvers and deep-space missions. Four future directions were considered for the Soviet Union’s space transportation program:

• the continued use of expendable launch vehicles and spacecraft until the year 2000;

• the continued use of expendable launch vehicles, but with standardized satellites;

• the use of a reusable space transportation system capable of returning spacecraft back to Earth for servicing and subsequent reuse;

image37

Reusable space transportation systems studied at Soviet research institutes in the early 1970s (source: Ts. Solovyov).

• the use of a reusable space transportation system capable of servicing and

repairing satellites in orbit.

As for reusable systems, the institutes explored two vehicle sizes, one able to accom­modate payloads of 30-40 tons (like the Space Shuttle) and another for payloads weighing 3-5 tons. Furthermore, two ways were studied of recovering the first stage, one involving the use of standard recovery techniques, the other requiring the use of reusable flyback boosters.

The six institutes presented their joint findings in June 1974. They concluded that the development of a reusable launch vehicle was only economically justified if the launch rate was very high, more particularly if the annual amount of cargo delivered to orbit would exceed 10,000 tons. However, it was stressed that much also depended on the vehicle’s capability of servicing satellites in orbit or returning them to Earth for repairs. The size of the spaceplane in itself would not determine its effectiveness and would have to depend on the mass and size of the payloads that needed to be launched or returned. Finally, it was recommended to perfect future reusable systems by developing first stages with air-breathing engines and eventually to introduce high-thrust nuclear engines for single-stage-to-orbit spaceplanes.

Basically, the conclusion was that a Space Shuttle type transportation system would not provide any major cost savings even if a relatively high launch rate was achieved and should be seen as nothing more than a first step towards developing more efficient transportation systems. However, the consensus was that if a reusable system were developed, preference should be given to a big shuttle akin to the American one [4].

On 27 December 1973, without awaiting the results of the studies, the VPK ordered three design bureaus to formulate so-called “technical proposals” for a reusable space transportation system. This is one of the first stages in a Soviet space project, in which various preliminary designs are worked out and compared in terms of their technical and economic feasibility. While the VPK order was significant in being the first official government-level decision on a Space Shuttle response, it was far from a commitment to build such a system, but merely an attempt to explore various vehicle configurations that might eventually lead to to a final decision later on. The three bureaus were MMZ Zenit (headed by Rostislav Belyakov after Mikoyan’s death in 1971), Chelomey’s TsKBM, and Mishin’s TsKBEM. They came up with two basically different concepts that reflected the conflict between a small vs. a large shuttle.

MMZ Zenit was best prepared to respond to this order, having worked since 1966 on its Spiral air-launched spaceplane and benefiting from actual suborbital flight experience with the BOR-1, 2, and 3 scale models. Strictly speaking, the space branch that had been set up in Dubna in 1967 to work on Spiral was no longer subordinate to MMZ Zenit, having merged in 1972 with MKB Raduga (another former branch of Mikoyan’s bureau) to form DPKO Raduga. The VPK order must have been a major morale booster for Lozino-Lozinskiy’s Spiral team, which because of a lack of government and military support had been forced to do its work on an almost semi-legal basis. It did require the team to divert its attention from the small air – launched Spiral, which had been primarily designed for reconnaissance, inspection, and combat missions. With the focus now shifting to transportation tasks, a larger version of Spiral with a higher payload capacity was needed. Although the details are sketchy, Lozino-Lozinskiy’s team seems to have studied an enlarged 20-ton version of the Spiral spaceplane launched by the Proton rocket.

TsKBM also set its sights on a 20-ton spaceplane to be orbited by the Proton, which itself was a product of Chelomey’s bureau. However, the spaceplane project seems to have been low on Chelomey’s list of priorities at this stage. Indications are that the bulk of spaceplane research at TsKBM was done in the late 1970s, by which time Buran had already been approved (see Chapter 9) [5].

TsKBEM was to focus on a Space Shuttle sized vehicle to be orbited by the N-1 rocket, but it appears that little, if any, work was done on this. The research was to be done by a small team headed by Valeriy Burdakov, but as Burdakov later recalled, the team’s work was limited to studying the possibility of reusing the first stage of the N-1 and keeping track of foreign literature on reusable space systems [6]. However, big changes were ahead at TsKBEM that would turn these plans upside down.