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UR-500 ICBM - UR-500 ICBM version - cutaway drawing showing arrangement of N2O4 oxidiser tanks (green) and UDMH fuel tanks (orange). The UR-500 was designed so that its components could be rail-transported and field assembled in siloes. Even Khrushchev considered the monster missile and its 100 MT warhead unaffordable - after he was deposed, the ICBM project was cancelled. The original third stage configuration with toroidal tanks was never flown.

Credit: © Mark Wade. 5,663 bytes. 60 x 322 pixels.

Family: UR. Country: Russia. Status: Hardware. Other Designations: Proton 2. Library of Congress Designation: D. Department of Defence Designation: SL-9. Article Number: 8K82. Manufacturer's Designation: UR-500.

The Proton launch vehicle has been the workhorse of the Soviet and Russian space programs, and will continue in use into the next century. Although constantly criticised within the Soviet Union for its use of toxic and ecologically-damaging storable liquid propellants, it has out-lasted all challengers and replacements, and will continue in use into the next century, launching Russian elements of the International Space Station.

The Proton had its origin in the early 1960’s, as a heavy two-stage rocket that could be used to launch large military payloads into space as well as act as a ballistic missile for nuclear warheads up to 100 MT in yield. Approval to proceed with the UR-500 8K82 was provided on 24 April 1962. The selected design solution was a conventional tandem vehicle. The upper stages would be modified versions of the UR-200 first and second stages. The first stage consisted of a centre large diameter oxidiser tank surrounded by several smaller diameter fuel tanks. The 4.15 diameter of the stages and their lengths were dictated by the requirement for rail transport of the completed stages from the factory to the launch site.

The draft project UR-500 was completed in 1963. On 16 July 1965 the first UR-500 successfully launched the Proton 1 satellite. The payload of the two-stage version was only 8.4 tonnes, only 24% more than Korolev’s Soyuz rocket, although the UR-500 was 75% larger. This would be rectified in the three-stage version, development of which had begun on 3 August 1964.

The Proton had its origin in the early 1960’s, at a time when all Soviet rockets required military justification to be developed. At this time the military-political leadership formulated a requirement for a heavy rocket that could be used to launch large military payloads into space as well as act as a ballistic missile for nuclear warheads up to 100 MT in yield.

There were competitors for the original military Global Rocket 2 (GR-2) requirement.

The OKB-1 of S P Korolev had begun design of the enormous N1 lunar rocket, and had already put the Soviet Union first in ballistic missiles and space through use of its R-7 ICBM. Korolev was working on the successor R-9 ICBM, and the NII variant of the N1(using the top two stages) could meet the GR-2 requirement.

M K Yangel’s KB Yuzhnoye proposed creation of two related launch vehicles to fulfil the military requirement - the R-46 heavy ICBM and the R-56 launch vehicle. These would cover the entire range of military requirements. Yangel’s OKB had already supplied the military with the great majority of its operational strategic rockets - the R-12 and R-14 IRBM’s and the R-16 ICBM.

OKB-52, under V N Chelomei, proposed to create a related family of rockets, each designed from the beginning for dual use as ballistic missiles and space launchers - the medium UR-200, the heavy UR-500 and the huge UR-700 for lunar requirements.

By 16 March and 1 August 1961 the Central Committee and Politburo had approved development of the UR-200 (8K81) universal rocket. The UR-200 draft project was completed in July 1962.

The GR-2 project required that the factory-completed modules of the rocket be transported by rail to the launch complex, quickly assembled at the site, followed by automatic erection and launch. Approval to proceed with the UR-500 8K82 was provided in the Central Committee decree of 24 April 1962. However Chelomei had begun studies on the design considerably earlier, in the second half of 1961.

At first the launch vehicle was simply to consist of 4 two-stage UR-200 rockets lashed together, the first and second stages working in parallel in clusters. A third stage would be modified from the UR-200 second stage. (Yangel proposed a similar solution, his R-56 rockets being composed of R-46’s clustered together). However study of this configuration, which included manufacturing of a dynamic test article (now in the Tsniimash museum), indicated that the payload capacity could not meet the military’s requirements.

The selected solution was to develop a conventional tandem three-stage vehicle. The upper two stages would be modified versions of the UR-200 first and second stages. However the first stage would have to be a new design. There were two logical solutions, both of which were implemented by the Americans in their rockets of the same class: to take a two stage rocket and attach large solid fuel boosters in parallel to the central body, as was done in the Titan 3C design; or to build a new powerful first stage, as was done on the Saturn I rocket. Chelomei additionally had to consider what would be needed for his UR-700 lunar launch vehicle. His solution was to build a core module of the largest possible rail-transportable diameter (4.15 m). This could consist of an oxidiser tank, or a fuel tank with the engine installation. The design had to meet requirements from two sides. On the one hand, the maximum length and diameter of the modules was dictated by the size of rail wagons and platforms, and existing rail tunnels, waterways, and turntables. On the other hand, the size of the rocket stage, and its corresponding volume and mass, were driven by the UR-500 launch mass and characteristics of the future UR-700.

Proton UR-500Proton UR-500 - Proton two stage configuration as flown in the first four launches. This version had a shorter second stage than the UR-500K that followed and only 40% of the payload.

Credit: © Mark Wade. 6,068 bytes. 72 x 322 pixels.

Two variants of the first stage were considered: polyblock and monoblock. The monoblock approach was that the first stage be assembled from two separate modules with the same diameter: an upper oxidiser module and a lower fuel and engine block. In assembly trials of this design it proved difficult, because of the height of the first stage, to obtain access to the upper stages and payload atop the rocket. The payload advantage of this design was relatively small compared to the alternative. This variant was studied by Chelomei’s Filial Number 1, Chief Designer V N Bugayskiy, under the lead engineer M S Mishetyan.

The second (polyblock) variant consisted of a centre large diameter oxidiser tank surrounded by several smaller diameter fuel tanks. This version could be assembled in a special rig with the lateral blocks being sequentially mounted on the centre. This had the advantage of easier installation of the upper stages and payload due to the smaller length of the first stage. This variant was studied in Filial 1 under the lead engineer E. T. Radchenko. In January 1962 This design was chosen as most advantageous, following studies that indicated improved wind loads and bending moment characteristics compared to the monoblock design. The polyblock design received patent number 36616 in 26 July 1966. Named on the patent were V N Chelomei, V N Bugayckiy, V A Birodov, G D Dermichev, N I Yegorov, V K Karrask, Yu P Kolesnikov, Ya B Nodelman, and E T Radchenko.

Another key issue was the selection of the engine for the first stage. In order that the rocket could meet the quick response requirements of the military, it was decided that it would use storable liquid fuels. These would allow the fuelled rocket to be held in readiness for quick launch over a wide range of temperature conditions and eliminate the need for thermostatically controlled storage of the rocket. Nitrogen tetroxide (N2O4) and unsymmetrical di-methyl hydrazine (UDMH) had already been selected as the propellants for the UR-200 and therefore for the corresponding upper stages of the UR-500. However the largest rocket engine developed for the UR-200 was the 50 tonne thrust 8D45 engine of S A Kosberg’s KBKhA design bureau. By the beginning of work on the UR-500 more than 700 trials of this engine had been undertaken, including 225 resource trials. The advantage of using this engine was that it could contribute to the desired short length of the first stage. However the drawback was that to achieve the required first stage thrust, 15 to 16 engines would have to be clustered, which, from the point of view of V N Chelomei, was much too many.

UR-500 First ConceptUR-500 First Concept - Drawing of the original design concept for the UR-500 heavy ICBM/space launcher. This consisted of a cluster of four UR-200 ICBM's, with a modified UR-200 second stage as the final stage. Dynamic tests were conducted of a model of this configuration, but it was abandoned by Chelomei due to poor payload performance.

Credit: © Mark Wade. 6,544 bytes. 73 x 455 pixels.

In November 1961 OKB-52 began to collaborate with V P Glushko’s OKB-456 in developing a more appropriate engine. Glushko had completed a storable liquid engine design of 150 tonnes for use in Korolev’s N1. However Korolev refused to accept this design, due to his refusal to use toxic propellants in his rockets and his belief that such propellants could never deliver the required specific impulse. Korolev insisted on development of an oxygen-kerosene engine; Glushko categorically refused to do so. As a result, the two leading Soviet rocket designers irrevocably split. Korolev had to turn for development of his N1 engines to the aviation engine OKB of N D Kuznetsov.

Since Chelomei agreed with Glushko on the selection of propellants, Glushko’s N1 engine instead went into the first stage of the UR-500. In May 1962 advanced project UR-500 was published. The initial design featured four ungimballed Glushko engines mounted below the core, with four steerable Kosberg engines on the lateral tanks. The second stage of the UR-500 was a larger-diameter variant of the first stage of the UR-200, with the engines gimballed for directional control. The third stage used the UR-200’s fixed engine with a four-nozzled steering engine. In order to meet the constant diameter requirement the third stage used toroidal propellant tanks.

Development of the engines and further elaboration of the study led to modifications to the original design of the first stage. Glushko conducted tests of the new engine from 1961 to 1963, followed by tests of the clustered engine assembly from June 1963 to January 1965. Through use of a regenerative fuel pump cycle Glushko was able to improve the thrust of the engine by 12.5%. It was therefore decided to use only the large Glushko engine in the first stage. The first layout had one engine at the base of the core and 4 to 8 fuel tanks with peripheral engines. Now the centre engine was abandoned and the ‘clean’ oxidiser tank core was surrounded by six fuel tank/engine assemblies. This had the advantage of reducing the length of the stage while increasing the dry weight fraction.

The 29 April 1962 decree ordered development of this powerful new rocket to be completed within three years. This was a difficult task, considering the factory and launch facilities that would have to be built to allow testing of the rocket to begin. Head of the original UR-500 development team was P A Ivensen. In 1962 this role was taken by Yu N Trufanov. At the project stage the technical parameters of the rocket were developed by D A Polukhin (subsequently chief of the team), V K Karrask, G D Dermichev, V A Virodov, E T Radchenko, E S Kulaga, N N Mirkin, Yu P Kolosnov, V F Gusev, and A T Tarasov.

Proton UR-500Proton UR-500 - The very first Proton UR-500 is enclosed by its launch gantry.

Credit: © Mark Wade. 22,778 bytes. 315 x 451 pixels.

As payloads for the UR-500 Chelomei considered a broad spectrum of space craft, destined to solve defence, scientific investigation, and national economic tasks. These were to be called raketoplans - piloted spacecraft for solving military tasks in space. For example, orbital raketoplans were intended to fulfil intelligence, satellite inspection, and destruction tasks. For these purposes the raketoplan was to be equipped with an orbital manoeuvring engine, targeting systems, rendezvous systems, and space-to-space weapons. Later raketoplans would be used for scientific tasks, including flight to the moon and return to earth, and economic exploitation of near-earth space. Due to their high lift to drag ratios, raketoplans could, after completing their tasks in space, make a guided descent into the earth’s atmosphere with a landing on Soviet territory.

The draft project UR-500 was completed in 1963. The fundamental technological problems of the project had been solved by the end of 1964. In the early fall of that year, Khrushchev and the political leadership of the country visited Baikonur. Chelomei with great pride guided Khrushchev around a dummy UR-500 installed in its launch gantry at the new launch complex, presented the heavy transporters for the launch vehicle and showed a scale model of the launch silo planned for the combat version. Khrushchev’s comment was ‘what should we build - communism or silos for the UR-500?" It was clear that Khrushchev was not very supportive of the military version of the UR-500.

Soon thereafter Khrushchev was ousted from power and the new leadership, under Brezhnev, was adverse to all projects Khrushchev had supported. This included Chelomei and his OKB-52. An expert commission under M V Keldysh was directed to examine all of Chelomei’s projects and make recommendations as to which should be cancelled. Keldysh found that Yangel’s R-36 universal rocket was superior to Chelomei’s UR-200. The UR-200 was accordingly cancelled. The UR-500 was to continue, not as a huge ICBM but only in the space launcher role. The raketoplan was stopped, but work on the high-priority LK-1manned lunar flyby program continued.

In the spring of 1965, when Chelomei’s activities were still under investigation, the Khrunichev factory completed construction of the first UR-500. In place of the third stage, an automated space physics laboratory ‘Proton’, for measurement of high energy particles, was built. The Proton satellites used the structural shell of the rocket’s third stage.

Proton UR-500Proton UR-500 - Model of the Proton UR-500 two stage configuration as first flown.

Credit: © Mark Wade. 7,160 bytes. 91 x 454 pixels.

All of the components were shipped by rail to Tyuratam for launch from the new rocket complex on the left (‘Chelomeevskoy’) arm of the range. The rocket was assembled in the Proton MIK assembly building at site 92 at Baikonur. The special transporter-installer took the rocket by rail from the MIK to launch site number 81, and the rockets was raised from the horizontal to the vertical position and installed on the launch table. Unlike the R-7 'Semyorka’, the ‘500 was not suspended above the flame pit but fastened by its tail directly on the launch table. The UR-500 had a very cleanly designed compound umbilical cable which connected all services to a single coupling in the base of the core oxidiser tank. This umbilical remained connected until the rocket reached a height of 100 to 150 mm, then automatically detached and was retracted into a protective cover on the launch pad. Doors also closed on the launch vehicle, making a hermetic seal.

The first launch was not without problems. A leak in the oxidiser pipeline resulted in nitrogen tetroxide spilling on electrical wires. The question was: proceed with the launch or abort? Chelomei decided to go ahead, and on 16 July 1965 the first UR-500 successfully launched the Proton 1 satellite. In the first hours after launch specialists from OKB-52 could only receive signals in the first hours that indicated the satellite was ‘alive’. However it later functioned normally and provided physics data for 45 days.

Aside from its index 8K82 and ‘company’ designation UR-500, at the first launch the rocket was called ‘Gerkules’ (other sources say ‘Atlantis’), as indicated by the large symbol on the second stage skin. This name was however was not taken up. In the open press it was known only by the name of its first payload, ‘Proton’.

Flight trials of the two-stage variant of the rocket went through 6 July 1966. In four launches three heavy Proton satellites reached orbit. The third launch failed when the second stage cut off, and the rocket crashed in the Akmolinsk region. The payload capacity of the Proton was given in the press as 12.2 tonnes; however this included the empty mass of the last stage. The payload of the two-stage version was really only 8.4 tonnes, only 24% more than Korolev’s Soyuz rocket based on the R-7, even though the UR-500 was 75% larger. These deficiencies would be rectified in the three-stage version, fully developed in accordance with the decree of 3 August 1964.

Proton 8K82Proton 8K82 - Proton 8K82 as flown in the first four Proton launches. This version had the shorter second stage of the GR-2 ICBM version, but lacked the cancelled UR-500 third stage. Payload with just two stages was hardly better than the much smaller Soyuz 11A511 launch vehicle.

Credit: © Mark Wade. 4,997 bytes. 60 x 305 pixels.


Launches: 4. Failures: 1. Success Rate: 75.00% pct. First Launch Date: 16 July 1965. Last Launch Date: 06 July 1966. LEO Payload: 8,400 kg. to: 200 km Orbit. at: 65.0 degrees. Liftoff Thrust: 902,100 kgf. Total Mass: 595,490 kg. Core Diameter: 4.2 m. Total Length: 39.0 m.

Proton 8K82 Chronology

1961 Aug 15 -
- 1961 November -
1961 Nov 15 -
- 1962 January -
- 1962 During the Year -
1962 Jan 15 -
1962 Apr 24 -
- 1962 May -
1962 May 15 -
- 1963 June -
1963 Jun 15 -
1965 Jul 16 - - 11:16 GMT. LV Configuration: Proton 8K82 s/n 207. Launch Site: Baikonur . Launch Complex: LC81L.
1965 Nov 2 - - 12:28 GMT. LV Configuration: Proton 8K82 s/n 209. Launch Site: Baikonur . Launch Complex: LC81L.
1966 Mar 24 - - 21:00 GMT. LV Configuration: Proton 8K82 s/n 211. Launch Site: Baikonur . Launch Complex: LC81L. FAILURE: Second stage malfunction.
1966 Jul 6 - - 12:57 GMT. LV Configuration: Proton 8K82 s/n 212. Launch Site: Baikonur . Launch Complex: LC81L.


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Last update 12 March 2001.
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