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Soyuz 7K-OK
Soyuz 7K-OK -

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The Russian Soyuz spacecraft has been the longest-lived, most adaptable, and most successful manned spacecraft design. In production for forty years, more than 230 have been built and flown on a wide range of missions. The design will remain in use with the international space station well into the next century.

The fundamental concept of the design can easily be summarised as obtaining minimum overall vehicle mass for the mission. This is accomplished by minimising the mass of the re-entry vehicle. There were two major design elements to achieve this:

This design concept meant splitting the living area into two modules - the re-entry vehicle, with just enough space, equipment, and supplies to sustain the crew during re-entry; and a living module. As a bonus the living module provided an airlock for exit into space and a mounting area for rendezvous electronics.

The end result of this design approach was remarkable. The Apollo capsule designed by NASA had a mass of 5,000 kg and provided the crew with six cubic meters of living space. A service module, providing propulsion, electricity, radio, and other equipment would add at least 1,800 kg to this mass for the circumlunar mission. The Soyuz spacecraft for the same mission provided the same crew with 9 cubic meters of living space, an airlock, and the service module for the mass of the Apollo capsule alone!

The modular concept was also inherently adaptable. By changing the fuel load in the service module, and the type of equipment in the living module, a wide variety of missions could be performed. The superiority of this approach is clear to see: the Soyuz remains in use 40 years later, while the Apollo was quickly abandoned.

In the Soviet Union, manned spacecraft design in the late 1950's was solely handled by engineers within Sergei Korolev's design bureau. Korolev had designed the Vostok manned spacecraft that gave Russia the lead in the space race in the first half of the 1960's. Studies for a follow-on to Vostok, with the objective of sending a manned capsule on a circumlunar flight, began in 1959 under Tikhonravov. At this point it was assumed that any such flight would require use of launch vehicles derived from Korolev's R-7 ICBM. Since planned derivatives of the R-7 could not put more than six tonnes into orbit, it was immediately obvious that a circumlunar spacecraft would have to be assembled in low earth orbit from several R-7 launches. Therefore it would be necessary to perfect techniques for rendezvous, docking, and refuelling of rocket stages in orbit. By 1960 to 1961 the studies, now dubbed 'L1', were expanded to cover automatic rendezvous and docking of several stages, and use of manipulators to assemble the stages.

Meanwhile the configuration of the re-entry vehicle for a Vostok follow-on was being investigated by other sections of Korolev's bureau. Lead for work on the re-entry problem was Section 11. There was no shortage of ideas. In 1959 Chief Designer Tsybin and Solovyev of Section 9 both offered designs for a winged manned spacecraft with a hypersonic lift-to-drag ratio of over 1.0. Prugnikov of Section 8 and Feoktistov of Section 9 proposed development of a ballistic capsule composed of variations of 'segmented spheres'. Korolev requested TsAGI, the state’s Central Aerodynamic/Hydrodynamic Institute, to investigate all possible configurations. In a letter from A I Makarevskiy to Korolev on 9 September 1959 TsAGI set out its study plan. Aerodynamic characteristics at various angles of attack for a wide range of winged, spherical, elliptical, sphere-with cones, and conical shapes were to be analysed at velocities from Mach 0.3 to Mach 25. The ballistic vehicle was to have a basic diameter of 2.5 m, a total internal volume of 3 to 3.5 cubic metres, and a living volume of 2 to 3 cubic metres. Separately considered for all configurations were aerodynamics of ejection seats or capsules with a diameter of 0.9 cubic metres and a length of 1.85 metres. Most of the work was promised for completion by the end of 1959. To exploit this database, Reshetin started a project group to conduct trade-off studies of the various configurations at the beginning of 1960. It was upgraded to a project sector, under the leadership of Timchenko, in 1961.

The 1960 studies considered various configurations of ballistic capsule, 'Utka' winged schemes of conventional aircraft layout, and tail-less hybrid configurations. As was done at General Electric, each configuration had a complete theoretical study, from the standpoint of aerodynamics, trajectories, resulting spacecraft masses, thermal protection requirements, and so on. By the end of 1960 it was found that the winged designs were too heavy for launch by the R-7 and in any case presented difficult re-entry heating problems that were beyond the existing technology. Studies of re-entry trajectories from lunar distances showed that a modest lift-to-drag ratio of 0.2 would be sufficient to lower G forces and allow the capsule to fly 3,000 to 7,000 km from its re-entry point and land on the Soviet territory. When the existing guidance accuracy were taken into account, this was increased to 0.3 to allow sufficient manoeuvrability to ensure the capsule could land within 50 km of the aim point.

These studies were the most complex ever undertaken, and Korolev obtained assistance from the most brilliant Soviet aerodynamicists, notably Likhushin at NII-1, and those refugees from Chelomei’s take-over of their bureaux, Myasishchyev at TsAGI, and Tsybin at NII-88. In 1962 the classic Soyuz 'headlight' configuration was selected: a hemispherical forebody transition in a barely conical (7 degree) section to the section-of-a-sphere heat shield.

Section 11 had conceived of the modular scheme to reduce the mass of the re-entry vehicle in 1960. Section 9's competing design was two modules, like Apollo. Further iterative studies in 1961 to 1962 reached the conclusion that the Soyuz should consist of four sections. From fore to aft these were the living module; the landing module; the equipment-propulsion module; and an aft jettisonable module, that would contain the electronics for earth orbit rendezvous (this was to be jettisoned after the last docking was completed and before translunar injection. Until recently this compartment on the early Soyuz models was misidentified as a 'toroidal fuel tank' by Western space experts).

This configuration was selected only after considerable engineering angst. From the point of view of pulling the capsule away from the rocket in an emergency, positioning the capsule at the top of the spacecraft was ideal. But to use this layout with the living module concept, a hatch would have to be put through the heat shield to connect the two living areas. Korolev's engineers just could not accept the idea of violating the integrity of the shield (and would later get in bitter battles with other design bureaux when competing manned spacecraft - Kozlov's Soyuz VI and Chelomei's TKS - used such hatches).

Allegations have been made that the Korolev Soyuz design was based on General Electric's losing Apollo proposal. However study of the chronology of the two projects shows that early development work was almost simultaneous. Independently of General Electric, Korolev had arrived at the modular spacecraft approach and a similar capsule concept before the General Electric proposal was published. However there was plenty of time to incorporate detailed features of the General Electric design into Soyuz before it was finalised.

On May 7, 1963 Korolev signed the final draft project for Soyuz. The baseline consisted of a circumlunar Soyuz A (7K) manned spacecraft. This would be boosted around the moon by the Soyuz B (9K) rocket stage, which was fuelled by the Soyuz V (11K) tanker. However Korolev understood very well that financing for a project of this scale would only be forthcoming from the Ministry of Defence. Therefore his draft project proposed two additional modifications of the Soyuz 7K: the Soyuz-P (Perekhvatchik, Interceptor) space interceptor and the Soyuz-R (Razvedki, intelligence) command-reconnaissance spacecraft. The Soyuz-P would use the Soyuz B rocket motor to boost it to intercepts in orbits of up to 6,000 km.

The Soyuz draft project was submitted to the expert commission on 20 March 1963. However only the reconnaissance and interceptor applications of the Soyuz could be understood and supported by the VVS air force and RVSN rocket forces. Korolev wanted to concentrate on the manned space exploration mission and felt he had no time to work on a Soyuz military ‘side-line’. In 1963 his OKB-1 was working on the three-crew 3KV Voskhod, the two-crew 3KD Voskhod-2, the immense N1 11A52 launch vehicle , its smaller derivatives 11A53 (N11) and 11A54 (N111), and a large number of other unmanned spacecraft. Therefore it was decided that OKB-1 would concentrate only on development of the 7K spacecraft, while development of the 9K and 11K spacecraft would be passed to other design bureaux. The military projects Soyuz-P and Soyuz-R were ‘subcontracted’ to OKB-1 Filial number 3, based in Samara.

To Korolev’s frustration, while Filial 3 received budget to develop the military Soyuz versions, his own Soyuz-A did not receive adequate financial support. The 7K-9K-11K plan would have required five successful automatic dockings to succeed. This seemed impossible at the time. Instead the road to the moon advocated by Vladimir Nikolayevich Chelomei was preferred. Chelomei was Korolev’s arch-rival, and had the advantage of having Nikita Khrushchev’s son in his employ. He attempted to break the stranglehold that ‘Korolev and Co.’, also known as the ‘Podpilki’ Mafia, had on the space program. Chelomei’s LK-1 single-manned spacecraft, to be placed on a translunar trajectory in a single launch of his UR-500K rocket, was the preferred approach. Chelomei issued the advanced project LK-1 on 3 August 1964, the same day the historic decree was issued that set forth the Soviet plan to beat the Americans to the moon. Under this decree Chelomei was to develop the LK-1 for the manned lunar flyby while Korolev was to develop the N1-L3 for the manned lunar landing. The 7K-9K-11K system was cancelled. But the Soyuz A itself would be developed by Korolev as the 7K-OK manned earth orbit spacecraft. Korolev kept his options open and had versions of it designed which would in the end be flown for manned orbital and circumlunar (7K-L1) missions.


Spacecraft: Sever.

Sever was the original OKB-1 design for a manned spacecraft to replace the Vostok. It was designed to tackle such problems as manoeuvring in orbit, rendezvous and docking, and testing of lifting re-entry vehicles. The Sever had the same ‘headlight’ shape as the later Soyuz re-entry vehicle, but was 50% larger. But application of the principal of moving all possible systems to a jettisonable living module resulted in the smaller Soyuz capsule design for the same number of crew.


Spacecraft: L1-1960.

In a letter to the Central Committee of the Communist Part in January 1960 Korolev proposed an aggressive program for Communist conquest of space. Among the potential payloads for his rocket in the period 1963 to 1965 Korolev mentioned an L1 'loop around the moon' vehicle with a mass during lunar flyby of 5 to 6 tonnes including a 2 to 3 tonne re-entry vehicle for return to earth. The final decree 715-296 of 23 June 1960 authorized draft project work on the L1 and the N1 booster. The L1 would evolve into the Soyuz A design of 1963.


Spacecraft: L4-1960.

In a letter to the Central Committee of the Communist Part in January 1960 Korolev proposed an aggressive program for Communist conquest of space. This would be accomplished by develpment of a new rocket of 1,000 to 2,000 tonnes gross lift-off mass with a 60 to 80 tonne payload at the earliest possible date. Among the potential payloads for his rocket in the period 1963 to 1965 Korolev proposed a spacecraft with 2 to 3 men for flyby of the moon, entry into lunar orbit, and return to earth. Payload mass would be 10 to 12 tonnes in lunar orbit with 2 to 3 tonnes return payload. This lunar orbiter would be twice as large as the L1 'loop around the moon' spacecraft. Korolev pledged to place before the Central Committee in the third quarter of 1960 comprehensive plans for development of the new projects. Following negotiations with other Chief Designers and the government, the final decree 715-296 of 23 June 1960 authorized draft project work on the L1 and the N1 booster but did not mention any N1-launched lunar orbiter.


Spacecraft: L1-1962.

The highest Soviet priority after the N1 large booster was a reliable spacecraft that allowed the crew to make re-entries at hyperbolic speeds - when returning from expeditions from earth orbit, the moon, or Mars. On 10 March 1962 Korolev approved the technical project "Complex docking of spacecraft in earth orbit - Soyuz". The Soyuz would first be tested using multiple launches of an R-7 derived rocket. In this concept a large spacecraft was assembled in earth orbit by a Vostok-Zh (or Vostok-7) manoeuvrable manned satellite, piloted by a 'cosmonaut assemblyman'. The pilot would rendezvous and dock with each component as it reached orbit, then manoeuvre the component to the in-assembly spacecraft. Following completion of assembly, the Vostok would retrofire and the assemblyman would return to earth. The assembled circumlunar craft consisted of three rocket blocks (RB) and the L1 Soyuz spacecraft itself. The rocket blocks would fire in sequence to put the L1, with a crew of one to three, on a circumlunar trajectory.

The original L1 had both main and back-up engines. It consisted of the ZhO living section, the SA re-entry capsule, AO aggregate (equipment/propulsion) section, followed by the three rocket blocks.

The Vostok-Zh could be used on another mission to assemble a 15 tonne orbital station with the mission of observing the earth. It would consist of three separately-launched blocks: a ZhO living section, BAA scientific apparatus block, and the Soyuz spacecraft itself. This closely resembled Sever, another contemporary study project at OKB-1.


Spacecraft: L3-1963.

Korolev’s first version of the L-3 manned spacecraft was described in a 23 September 1963 letter setting out the space exploration plan for 1965 to 1975. The L3 was designed to make a direct lunar landing using the earth orbit rendezvous method. It was a 200 tonne spacecraft requiring three N1 launches and a single Soyuz 11A5ll launch to assemble in low earth orbit. The first N1 launch would place the 75 tonne partially-fuelled TLI stage and L3 spacecraft (except the L1 manned return craft) into low earth orbit. Two further N1 launches would orbit 75 tonne tankers which would rendezvous and dock with the first payload and top off its propellant tanks. Then the Soyuz would be launched for an automated rear-end docking with the entire L3 stack.


Spacecraft: L4-1963.

The L-4 Manned Lunar Orbiter Research Spacecraft would have taken two to three cosmonauts into lunar orbit for an extended survey and mapping mission. It was described in a 23 September 1963 letter setting out the space exploration plan for 1965 to 1975. The L-4 complex, with a total mass of 75 tonnes, would be placed into orbit in a single N1 launch, and would consist of:

  • The trans-lunar injection stage, total mass 58 tonnes. If development of a fourth stage for the N1 was not authorised, this could be replaced by three sequentially-fired Soyuz B 9KM rocket blocks developed for the L-1 and L-2 projects.
  • The lunar orbit manoeuvring stage, which would have a total mass of 11.5 tonnes. This would break the Soyuz manned spacecraft into lunar orbit and returned it on its transearth trajectory. Five tonnes of propellant would be used for lunar orbit insertion.
  • The L-4 spacecraft, which would be a modification of the 7K Soyuz. This would have a mass of 5.5 tonnes after being placed on a transearth trajectory with a descent capsule mass of 2.5 tonnes.

Spacecraft: L5-1963.

The L-5 Heavy Lunar Self-Propelled Craft would be used for extended manned reconnaissance of the lunar surface. It was described in a 23 September 1963 letter setting out the space exploration plan for 1965 to 1975. With a maximum speed of 20 km/hour, it would provide living accommodation for three cosmonauts and 3,500 kg of provisions. The crews themselves would be landed on the moon using the L-3 complex.


Spacecraft: Soyuz A.

The 7K Soyuz spacecraft was initially designed for rendezvous and docking operations in near earth orbit, leading to piloted circumlunar flight. Soyuz continued the themes of the earlier Sever project. In the definitive December 1962 Soyuz draft project, the Vostok-Zh of the 1962 technical project was gone and Soyuz appeared as a complete two-place spacecraft. The design included two other spacecraft - the Soyuz B 9K rocket acceleration block and Soyuz V 11K tanker. All of these would be launched into orbit by Soyuz 11A511 boosters. A circumlunar mission would begin with launch of the Soyuz B 9K rocket block into a 225 km orbit. This would be followed by one to three Soyuz V 11K tankers (depending on the mission), which would automatically rendezvous and dock with the 9K. They would transfer up to 22 tonnes of propellant. Finally the 7K spacecraft with the cosmonauts aboard would be launched, dock with the 9K, and be propelled on a lunar flyby trajectory.

The Soyuz A consisted, from fore to aft, of the living module (BO), the landing capsule (SA), the equipment module (PO), the propulsion module (NO) and the rendezvous electronics module (AO). This last toroidal module would be jettisoned before the Soyuz B rocket burn to minimise mass. It was retained in the initial Soyuz 7K-OK design and is misidentified in most earlier books as a ‘toroidal fuel tank’).

The 7K would be equipped with cinema cameras and scientific sensors to record the lunar surface during the flyby, which would be at from 1,000 to 20,000 km from the lunar surface. Total flight time was 7 to 8 days. The SA would separate from the 7K at 120 to 150 km altitude and re-enter the earth’s atmosphere at 11 km/sec. After decelerating to subsonic speed, the SA’s parachute would open at 10-18 km altitude. Total mass of the L1 in low earth orbit was 23,000 kg and the flyby mass of the Soyuz alone was 5,100 kg.


Spacecraft: Soyuz B.

In the definitive December 1962 Soyuz draft project, the Soyuz B (9K) rocket acceleration block would be launched into a 225 km orbit by a Soyuz 11A511 booster. Following refuelling by the required number of Soyuz V (11K) tanker spacecraft, a manned Soyuz spacecraft would rendezvous and dock with the 9K. It would then be boosted on its mission (circumlunar, satellite intercept, or high earth orbit).

The 9K consisted of the rocket block itself and an ‘NO’ rendezvous and docking module. The NO module provided a docking and fuel transfer system, guidance equipment, and storable propellant manoeuvring rocket systems.


Spacecraft: Soyuz P.

In December 1962 Sergei Korolev released his draft project for a versatile manned spacecraft to follow Vostok. The Soyuz A was primarily designed for manned circumlunar flight. However Korolev understood very well that financing of the scale required could only come from the Ministry of Defence. Therefore his draft project proposed two additional modifications of the 7K: the 7K-P (Perekhvatchik, Interceptor) space interceptor and the Soyuz R (Razvedki, intelligence) command-reconnaissance spacecraft. In the initial draft project, the Soyuz-P would use the Soyuz-B rocket stage and Soyuz-V tanker spacecraft and conduct a series of dockings and fuelling. The complete complex then could conduct intercepts of enemy satellites in orbits up to 6,000 km altitude.


Spacecraft: Soyuz R.

In December 1962 Sergei Korolev released his draft project for a versatile manned spacecraft to follow Vostok. Among the designs was the Soyuz P interceptor and Soyuz R (Razvedki, intelligence) command-reconnaissance spacecraft. The VVS and the Strategic Rocket Forces supported these variants of the Soyuz. They were fully aware that the US Air Force’s Manned Orbiting Laboratory was in the advance concept stage (it would be approved for development on December 10, 1963). But Korolev had no time to work on Soyuz ‘side-lines’. Therefore he decided to 'subcontract' the military projects Soyuz-P and Soyuz-R to OKB-1 filial number 3, based in Samara (then Kuibishev), headed by Chief Designer Dmitri Ilyich Kozlov.

The Soyuz-R system consisted of two separately launched spacecraft, with the docked complex having a total mass of 13 tonnes. The small orbital station 11F71 would be equipped with photo-reconnaissance and ELINT equipment. This station was based on the Soyuz 7K, but the descent apparatus and living module were replaced with a storage section for modular equipment (this would later be developed further as a free-flyer spacecraft for the giant MOK orbital complex 19K, finally resulting in the 1990 (!) autonomous spacecraft 19KA30 Gamma). It is interesting to note that the external appearance of the Soyuz-R was very similar to pictures published on 1 November 1967 of the docking of Kosmos 186 and 188. These spacecraft were actually 11F615 7K-OK Soyuzes, but at that time the configuration was still secret. Therefore the configuration of the by-then cancelled 7K-R was used for the public release.

To dock with the Soyuz R 11F71 station Samara developed the transport spacecraft 11F72 Soyuz 7K-TK. This version of the Soyuz was equipped with rendezvous and docking equipment, including a hatch in the docking collar that allowed the cosmonauts to enter the station without donning space suits.


Spacecraft: Soyuz V.

In the definitive December 1962 Soyuz draft project, the Soyuz B (9K) rocket acceleration block would be launched into a 225 km orbit by a Soyuz 11A511 booster. Following refuelling by tone to three Soyuz V (11K) tanker spacecraft, a manned Soyuz spacecraft would rendezvous and dock with the 9K. It would then be boosted on its mission (circumlunar, satellite intercept, or high earth orbit).


Spacecraft: Soyuz 7K-OK.

In the second quarter of 1963, when Korolev had begun design of the Voskhod multi-manned spacecraft, he instructed his bureau to begin design of a three-manned orbital version of the Soyuz, the 7K-OK. Korolev finally obtained approval for this spacecraft in the decree of 3 December 1963.

The 7K-OK earth-orbit version of Soyuz as developed in accordance with the decrees of 16 April 1962 and 3 December 1963 was to be capable of the following:

  • Automatic rendezvous with other spacecraft
  • Automatic approach and alignment
  • Automatic docking
  • Exit of crew into open space for transfer from spacecraft to spacecraft
  • Astronavigation
  • Maneuvering in orbit (changing of orbital parameters)
  • Test of re-entry using body lift to modify the landing point and alleviate G-forces
  • Test of the operation of radio equipment and tracking equipment
  • Scientific research

Spacecraft: Soyuz PPK.

The Soyuz 7K-PPK (pilotiruemiy korabl-perekhvatchik, manned interceptor spacecraft) was a revised version of the Soyuz P manned satellite inspection spacecraft. The PPK provided the cosmonaut with a standoff capability for destruction of enemy satellites. For this purpose the Soyuz was equipped with eight small rockets. As in the Soyuz P, the spacecraft would rendezvous with the enemy satellite. But the cosmonaut would remain in the spacecraft, using visual and other on-board systems to inspect the satellite. If the satellite was to be eliminated, the Soyuz would back off to a distance of 1 kilometre, and then destroy it using the on-board rocket-mines. Delays in the development of the Soyuz led to abandonment of this plan.


Spacecraft: Soyuz 7K-OK Tether.

Korolev was always interested in application of artificial gravity for large space stations and interplanetary craft. He sought to test this in orbit from the early days of the Vostok programme. Two Soyuz versions were considered:

  • Soyuz 7K-OK, tethered to Block I

  • Two Soyuz 7K-OK, which would rendezvous and dock in orbit and then undock, pulling the tether out between them.

Spacecraft: Soyuz VI.

To determine the usefulness of manned military space flight, two projects were pursued in the second half of the 1960's. Chelomei's Almaz was to conduct orbital research into the usefulness of manned observation of the earth, while Kozlov's Soyuz VI would conduct military research. Soyuz VI was developed form the original Soyuz draft project. The standard Soyuz solved problems of docking, EVA, orbital assembly, while the VI was designed in response to a TTZ to solve military aspects - manned earth observation, orbital inspection and destruction of enemy satellites. But by the beginning of the 1970's flight tests had provided convincing evidence that near-earth operations were better suited to solution of national economic problems than military ones. So the Soyuz VI was cancelled.


Spacecraft: Soyuz 7K-L1P. First protoype version of the Soyuz 7K-L1 circumlunar craft. The L1P's had only boilerplate descent modules and were not capable of reentry and recovery.

Spacecraft: Soyuz 7K-L1.

The Soyuz 7K-L1, a modification of the Soyuz 7K-OK, was designed for manned circumlunar missions. With a complex genesis, the spacecraft was flown as a replacement for Chelomei's LK-1. The forward living module was deleted, as was the reserve parachute (in order to add an exit hatch in the side of the re-entry capsule). Special on-board systems were added for interplanetary navigation. The SAS launch escape system, more powerful than that for the earth orbital verison of Soyuz, could pull the spacecraft away from a failing Proton booster up to the point of second stage ignition. A Spacecraft Support Cone (OK) was mounted on the forward hatch of the Soyuz capsule to provide a point of attachment for the SAS. This was jettisoned before Block D ignition for translunar injection. The 7K-L1 never actually demonstrated that it could safely take a cosmonaut around the moon and return him to earth until August 1969, a month after the successful American Apollo 11 landing on the moon. By then any thoughts of a manned flight had been abandoned as too little and too late. The Soviet disinformation organs began disseminating the myth that the USSR had never been in the moon race at all. The project was cancelled in 1970.


Spacecraft: Soyuz 7K-TK.

To deliver crews to the Soyuz R 11F71 station Kozlov developed the transport spacecraft 11F72 Soyuz 7K-TK. This version of the Soyuz was equipped with rendezvous and docking equipment, including a hatch in the docking collar that allowed the cosmonauts to enter the station without donning space suits. Kozlov’s design for the docking system provided the basis for the 7K-OKS Soyuz space station ferry put into development five years later. The launch vehicle for the 7K-TK would be the 11A511, in use to this day as the ‘Soyuz’ launch vehicle. The Soyuz 7K-TK was in development until March 1966 for the Soyuz-R station. This was then cancelled and replaced by Chelomei's Almaz station. In June 1970 Chelomei was able to obtain approval for development of his TKS manned ferry craft in replace of the Soyuz 7K-TK, which was finally and definitely cancelled.


Spacecraft: Yantar-1.

Survey reconnaissance satellite project of KB Yuzhnoye worked on 1964-1967. The DS satellites of KB Yuzhnoye (Chief Constructor V M Kovtunenko) were used to solve problems related to the planned Yantar series. But Yuzhnoye was too busy building ICBM's for the RSVN (Soviet Rocket Forces). So Kozlov's Filial 1 of OKB-1 took up the project after a delay in 1967 to 1969. Succeeded by Kozlov's Yantar-1KF. Was to have been derived from Soyuz-R manned spacecraft.


Spacecraft: Yantar-2.

High resolution reconnaissance satellite project worked on by KB Yuzhnoye 1964-1967. Was to have been derived from Soyuz-R manned spacecraft. The DS satellites of KB Yuzhnoye (Chief Constructor V M Kovtunenko) were used to solve problems related to the planned Yantar series. But Yuzhnoye was too busy building ICBM's for the RSVN (Soviet Rocket Forces). So Kozlov's Filial 1 of OKB-1 took up the project after a delay in 1967 to 1969. Succeeded by Kozlov's very different Yantar-2K.


Spacecraft: Soyuz 7K-L1A.

Hybrid spacecraft used in N1 launch tests. The L1A consisted of a modified Soyuz L1 service module attached to an LOK-sized flange, with a circumlunar Soyuz descent module, topped by an odd hybird propulsion module derived from that to be used on the LOK and LK lunar lander. Probably each L1A differed somewhat from the other, using available surplus components or systems ready for test in space.


Spacecraft: Soyuz 7K-L1E.

Modification of Soyuz circumlunar configuration used in propulsion tests of Block D stage. The L1E provided guidance to the Block D and was equipped with television cameras that viewed the behavior of the Block D stage propellants under zero-G conditions. Probably included a dummy descent module (not recovered).


Spacecraft: Soyuz 7K-S.

The Soyuz 7K-S had its genesis in military Soyuz designs of the 1960's. These were cancelled in February 1970. The Soyuz 7K-S, however continued in two parallel designs - the base variant, which was for special-purpose military solo missions; and a space station transport variant 7K-ST. The revised designs for the 7K-S were completed on 11 August 1972. The initial Soyuz 7K-S program was to consist of four unmanned, followed by two manned test flights, then two operational launches. The draft design for 7K-ST space station transport version was completed in August 1974.

Following the fourth N1 launch failure, a major reorganisation of Soviet space enterprises was undertaken. The 7K-S was cancelled; experiments planned for the solo flights were transferred to the Salyut program. However the first three test vehicles had been completed and were launched unmanned as technology tests. The Soyuz 7K-ST transport project continued, except now being redesigned for a crew of three. The 7K-ST, following extended development, would eventually fly as the Soyuz T and Soyuz TM ferry to the Salyut 7 and Mir space stations.


Spacecraft: Soyuz Kontakt.

Modification of the Soyuz 7K-OK spacecraft to test in earth orbit the Kontakt rendezvous and docking system. Kontakt was developed for the lunar orbit rendezvous of the 7K-OK manned lunar orbiter and LK lunar lander. It utilised a hexagonal grid on the passive craft and a three-pronged grappler on the active spacecraft to allow a soft docking between the two spacecraft. The Kontakt system used manual optical methods for rendezous and docking rather than the heavier automatic Igla radar system mounted on the 7K-OK. No hard docking was possible and crew transfer was by extravehicular activity. The 7K-OK adaptation would have involved launch of two Soyuz by 11A511 boosters, with rendezvous and crew transfer in earth orbit. Crews were trained for these tests but due to delays and final cancellation of the N1-L3 lunar orbit rendezvous mission, the spacecraft never flew.


Spacecraft: L3M-1970.

The original draft project prior to 1970 for the N1M-L3M lunar landing complex anticipated use of a two-launch profile. On the first launch a Block R TB braking stage would be put on a translunar trajectory. The TB would place itself in lunar orbit. Next, the manned L3M lunar lander would be launched. This new spacecraft was much larger than the LK, with a mass of 21 tonnes landed on the lunar surface. The L3M would dock, tail-first, with the TB stage in lunar orbit. The RTB would act as a lunar crasher stage. The L3M would separate from the TB just over the lunar surface, then hover to a soft landing. The crew would spend up 16 days on the surface. Following completion of their work, the landing legs would be left behind, and the L3M would launch itself on a trans-earth trajectory. Just before arrival at earth, the crew would enter their Soyuz capsule, separate from the L3M, and make a lifting re-entry into the earth's atmosphere. It was felt that within the existing funding allocation of the original N1-L3 programme, enough N1's would be available to support a series of landings in 1978-1980.

In this earlier L3M, the Soyuz return capsule is perched atop the landing stage. A small toroidal crew compartment provides accommodation for space-suited cosmonauts to land the vehicle on the moon. Evidently the crew, which would have been limited to two cosmonauts, would be required to space walk from the Soyuz capsule to the toroidal chamber prior to the landing attempt. A return spacewalk would have to be made after ascent from the surface. This L3M had a landed mass of 21 tonnes on the surface, an ascent mass of 18 tonnes, a trans-earth injection spacecraft mass of 5 tonnes, and sufficient supplies for 14 to 16 days of operations on the surface.


Spacecraft: LK.

The LK ('Lunniy korabl' - lunar craft) was the Soviet lunar lander - the Russian counterpart of the American LM Lunar Module. The LK was to have landed a Soviet citizen on the moon before the Americans, winning the moon race. This was not to be, for reasons covered elsewhere (see Soviet Manned Lunar Projects). Because the translunar payload of the Russian N1 rocket was only 70% that of the American Saturn V, the LK differed in many ways from the LM. It had a different landing profile; it was only 1/3 the weight of the LM; it was limited to a crew of one; it had no docking tunnel (the cosmonaut had to space walk from the LK to the LOK lunar orbiter). Unlike the LM, the LK did not use a separate descent stage to go from lunar orbit to landing on the surface. A braking stage, the Block D, took the LK out of lunar orbit and slowed it to 100 m/s at an altitude of 4 km above the lunar surface. From there the LK used the engines of its Block E stage to soft land on the moon. The Block E also served as the ascent stage to return the LK to lunar orbit.

The LK consisted of four primary modules:

  • The LPU landing gear, which allowed landing on the lunar surface. The LPU remained behind on the lunar surface, acting as a launch pad for the rest of the LK
  • The Block E rocket stage, which soft landed the LK on the moon and returned it to lunar orbit
  • The Lunar Cabin, the pressurised semi-spherical cabin where the cosmonaut was located
  • The Integrated Orientation System, a pod of small thrusters to orient the spacecraft. Atop the pod was the large hexagonal grid of the Kontakt docking system

Spacecraft: Soyuz 7K-LOK.

The two-crew LOK manned lunar orbiting spacecraft was the largest derivative of Soyuz developed. The BO orbital module differed from the basic Soyuz in having the Kontakt lightweight docking system, a forward reaction control system module, and a cupola allowing the cosmonaut to make a manual visual docking with the LK lunar lander. The PO/AO service module was radically different from others in the Soyuz series. It featured the Block I propulsion system with a much more powerful engine and greater fuel capacity (required to put the spacecraft on the trans-earth trajectory from lunar orbit). Power was provided by Lox/LH2 fuel cells, also a first for a Soviet spacecraft (radioisotope nuclear batteries were advocated by some factions during development but not adopted).


Spacecraft: Soyuz 7KT-OK.

This was a modification of Soyuz 7K-OK with a lightweight docking system and a crew transfer tunnel. This was evidently derived from work done by Kozlov for the Soyuz 7K-TK ferry craft. It flew only twice. The Soyuz 10 mission could not dock with the Salyut 1 station despite several attempts. Soyuz 11 was successful until return to earth. A valve between the descent and orbital modules jarred open when the OM separated. The DM cabin atmosphere vented into space, killing the three man crew, who flew without spacesuits. After this the Soyuz underwent a complete safety redesign to the Soyuz 7K-T configuration.


Spacecraft: L3M-1972.

In July 1970 Kuznetsov was given authorisation to design substantially improved versions of the N1 rocket engines. The N1 that would utilise these engines was designated the N1F and would have a payload to a 225 km orbit of 105,000 kg.

Full go-ahead to develop a liquid hydrogen/liquid oxygen high energy upper stage for the N1F finally came in June 1970. The decision was made to develop a multi-engine Block Sr with a propellant mass of 66.4 tonnes. This single stage would be used in place of the previously-planned Blocks S and R to insert spacecraft of what was now termed the Lunar Expeditionary Complex (LEK) into low lunar orbit. It was also to be used to insert heavy spacecraft into geosynchronous orbit and on interplanetary trajectories.

The revised L3M for use with the Block Sr completed design in 1972. In this version the Soyuz capsule is completely enclosed in a pressurised ‘hangar’ (the OB, cocooned habitation block) which provides the crew with accommodation space. In this variant the crew could simply step out of the capsule into the hangar area without having to don space suits and conduct an EVA. This L3M would have had a mass of about 23 tonnes landed on the surface and have allowed stays of up to 90 days by a crew of three. The two-launch scenario would still be followed, with a single Block Sr from each N1 launch taking over duties of both the Blocks S and R in the previous plan. The DU engine block would perform the same ascent stage duties as the Block E of the original LK.


Spacecraft: Soyuz 7K-T.

Following the disastrous Soyuz 11 flight, when the crew was killed by cabin depressurisation, the 7K-OKS design was subjected to a complete redesign, resulting in the substantially safer 7K-T space station ferry. One crew position was eliminated, making it possible for the two crew members to wear pressure suits during dangerous phases of the flight. Batteries replaced the solar panels of the earlier configuration, to eliminate the chance of undeployed panels causing problems as was the case on Soyuz 1. Numerous minor changes were made to improve the basic safety and redundancy of the design. The 7K-T would safely fly 31 times until replaced by the Soyuz T in 1981.


Spacecraft: LEK.

LEK = Lunniy ekspeditionniy korabl', lunar expedition spacecraft. As in the original LK lunar lander, this would be taken to near zero velocity near the lunar surface by the Vulkan Block V 'lunar crasher' rocket stage. It would then descend to the lunar surface using a landing stage nearly identical to the American lunar module descent stage. This landing stage however would primarily provide propulsion of the upper Ascent/earth recovery stage to a trans-earth trajectory. The Ascent/earth recovery stage consisted of a re-entry capsule in the shape of but larger than the Soyuz descent module, encapsulated in a larger pressurised volume providing crew quarters and equipment storage.


Spacecraft: Lunokhod LEK.

Lunar rover for the Lunar Expedition. The rover provided pressurized quarters for 2 crew, allowing trips up to 200 km from the lunar base at a top speed of 5 km/hr. The 2.25 tonne generating station provided 8 kw of solar power to run the motor. Each 12 day trip would use 200 kg of life support consumables.


Spacecraft: LZhM.

LZhM = Laboratorno-zhiloy modul' = Laboratory-living module. Three story lunar surface residence and laboratory for Vulkan-launched Lunar Expedition. Atop the landing stage was a four-lobed first story. Clockwise from the landing leg with the ladder to the surface, this consisted of cylindrical chambers containing: the airlock; crew washroom and kitchen; sample storage area; and control room. At the junction of the four cyclinders was the crew dining and meeting table. Atop this was a two storied cylinder. On the lower story was the laboratory; atop this was the crew quarters. Total floor space devoted to work activities was 25 square meters, with 35 square meters devoted to crew quarters. The LLM would have been braked close to the lunar surface with the Block R stage, the descent stage itself only performing final descent and landing maneuvers. The crew would land in an LEK near the LLM and take up residence in it for up to a year.


Spacecraft: LZM.

LZM = Laboroatorno-zavodskoy modul' = Laboratory-Factory Module. Single story, four-lobed facility dedicated to lunar surface biological and physics research and production of oxygen from lunar soil for long-duration stay on the lunar surface. Clockwise, from the entry ladder: airlock; biological laboratory; oxygen production factory with scoop for digging lunar soil; physics-chemistry laboratory. An attic above the center contained hydroponic facilities for growing fresh food. Equipment weights: Biological lab, 950 kg; Physics-chemistry lab, 1,920 kg; oxygen factory, 3,200 kg. The LZM would be normally tended by one operator, who would live in the LZhM.


Spacecraft: Soyuz 7K-T/A9. Version of 7K-T for flights to Almaz; unknown but probably minor differences with the Soyuz 7K-T model for Salyut. May have incorporated equpment designed for the Soyuz 7K-TK, which had been intended for docking with Almaz in 1966-1970.

Spacecraft: Soyuz ASTP.

The Soyuz 7K-T as modified for the docking with Apollo. The spacecraft included some systems developed for the cancelled Soyuz S, including a new launch escape tower. Other changes included new lightweight solar panels to increase endurance; an androgynous universal docking mechanism in place of standard Soyuz male mechanism; unique radio aerials for common communications; optical docking targets for manual docking with Apollo; and modifications to the environmental control system to lower the cabin pressure to 0.68 atmospheres prior to docking with Apollo..


Spacecraft: Aelita.

The Aelita infrared astronomical telescope spacecraft was derived from the Soyuz manned spacecraft and had an unusually long gestation. The basic design was first conceived in 1965 as part of a 'Cloud Space Station' - a primary space station from which a number of man-tended, free-flying spacecraft would operated. This evolved by the early 1970's into the MKBS/MOK space station complex. Various spacecraft with specialised laboratories or instrument sets would fly autonomously away from the huge N1-launched main station. Aelita was originally to be a free-flyer of this complex. The Soyuz propulsion system was used, but the descent and orbital modules were replaced by a large pressurised cylinder containing the scientific instruments.

Work on the instrument payload began in 1972. However that same year the N1 launch vehicle, and the MKBS space station, were cancelled.

The Soviet space program was completely reformulated in a resolution of February 1976, which included authorisation to develop the free flyer in conjunction with the DOS-7/DOS-8 space station (which would eventually evolve into Mir). The draft project for Aelita was completed in 1978, and production was authorised together with Mir on 16 February 1979. At this point Aelita may still have included a passive docking port so that the spacecraft could be serviced by Soyuz manned spacecraft. It was planned that at six and twelve months into its one year mission Gamma would be visited by a two-crew Soyuz, who would replace film cassettes and repair or replace instruments. The spacecraft was cancelled in 1982. It's sister spacecraft, the Gamma, continued due to French involvement in the project, and finally flew in 1990.


Spacecraft: Soyuz 7K-MF6. Soyuz 7K-T modified with installation of East German MF6 multispectral camera. Used for a unique solo Soyuz earth resources mission.

Spacecraft: Soyuz 7K-TM. Improved version of Soyuz 7K-T ferry with unknown differences with basic model.

Spacecraft: Progress. Launch Escape System: Separation motors only; tower configuration same to preserve aerodynamics.

Spacecraft: Soyuz T.

Soyuz T had a long gestation, beginning as the Soyuz VI military orbital complex Soyuz in 1967. It finally emerged as a complete redesign of the Soyuz in the late seventies. The Soyuz T introduced a revised Igla rendezvous system and a new service module with unitary translation / attitude control thrusters as part of a single bipropellant system with the main pump-fed engine. Solar panels were reintroduced; the fuel load was increased; and all new digital avionics were developed. Crew safety was improved with a new launch escape system and accomodation was provided for the first time for a three-man crew in spacesuits.


Spacecraft: LK Energia.

LK= Lunniy korabl', lunar spacecraft. Lunar lander for Energia-based lunar expedition. The LOK and LK lander would be inserted into lunar orbit by separate Energia launches. After rendezvous and docking in lunar orbit, three of the five crew aboard the LOK would transfer to the LK and descend to the lunar surface. After 5 to 10 days (5 days standard, 10 with additional consumables) on the surface, the ascent stage of the LK would return to lunar orbit, and the crew would transfer back to the LOK. Prior to landing an unmanned Lunokhod would scout the region, allowing selection of a suitable landing site, and serve as a landing beacon for the precision LK landing.


Spacecraft: LOK Energia.

LOK = Lunniy orbital'niy korabl' = lunar orbiting spacecraft. Lunar orbiter for Energia-based lunar expedition. The LOK and LK lander would be inserted into lunar orbit by separate Energia launches. After rendezvous and docking in lunar orbit, three of the five crew aboard the LOK would transfer to the LK and descend to the lunar surface. After 5 to 10 days on the surface, the ascent stage of the LK would return to lunar orbit, and the crew would transfer back to the LOK. The LOK would remain in lunar orbit for a full lunar day (29 days) until returning to earth.


Spacecraft: Zarya.

'Super Soyuz' replacement for Soyuz and Progress. Concept was reusable spacecraft, launched by Zenit launch vehicle, with all possible systems recovered in landing module, together with significant payload delivered to and returned from orbit. Carriage in payload bay of Buran shuttle was also a requirement. Preliminary design work began on 27 January 1985. The design was briefed to the Military-Industrial Commission on 22 December 1986. However the project was cancelled in January 1989 on financial grounds.


Spacecraft: Soyuz TM.

Purpose-built for use with Mir and follow-on space stations. Kurs rendezvous and docking system permits Soyuz to maneuver independently of the station, without the station making "mirror image" maneuvers to match unwanted translations translations introduced by earlier models' aft-mounted attitude control. Lighter rendezvous system and improved launch escape tower permit higher payloads, more fuel, to be carried.


Spacecraft: Progress M. Progress M was an upgraded version of the original Progress. New service module and rendezvous and docking systems were adopted from Soyuz T. It also introduced use of a new launch fairing without a dummy launch escape system.

Spacecraft: Gamma.

The Gamma USSR/France gamma/x-ray astronomical telescope spacecraft was derived from the Soyuz manned spacecraft and had an unusually long gestation. The basic design was first conceived in 1965 as part of a 'Cloud Space Station' - a primary space station from which a number of man-tended, free-flying spacecraft would operated. This evolved by the early 1970's into the MKBS/MOK space station complex. Various spacecraft with specialised laboratories or instrument sets would fly autonomously away from the huge N1-launched main station. Gamma was originally to be a free-flyer of this complex. The Soyuz propulsion system was used, but the descent and orbital modules were replaced by a large pressurised cylinder containing the scientific instruments.


Spacecraft: Progress M2.

As Phase 2 of the third generation Soviet space systems it was planned to use a more capable resupply craft for the Mir-2 space station. By using the Zenit launch vehicle the Progress M service module module could accomodate much larger cargo or space station modules. The planned Progress-M2 11F615A75 was originally designed for use with the 90 tonne module Mir-2. Redesigned in 1992-1993 for use with the more modest Mir-2 it had a revised index number of 11F615A77. The 13.3 tonne, 12.6 m long vehicle consists of the 5.3 tonne service module, a 2.3 tonne pressurised forward module equipped with a docking port, and could hold 5.7 tonnes of cargo. It could also be outfitted as a laboratory and left docked with the Mir-2.

After the cancellation of Mir-2 and its incorporation into the International Space Station, Progress M2 was at first considered as the resupply craft. But as Russia's financial crisis deepened, and in recognition that the booster for the spacecraft was not built in a foreign country (the Ukraine), the design was dropped.


Spacecraft: Alpha Lifeboat.

1995 joint Energia-Rockwell-Khrunichev design for space station Alpha lifeboat based on the Zarya reentry vehicle with a solid retrofire motor, cold gas thruster package. Five years on-orbit storage. Design rejected in June 1996 in favor of use of a modified Soyuz TMA in short term, US X-38 in long term. Mass per crew 1560 kg.


Spacecraft: Progress M1.

Progress M1 was a modified version of the Progress M resupply spacecraft capable of delivering more propellant than the basic model to the ISS or Mir. A Russian funded component of the ISS programme, the Progress M1 can carry a maximum total of 2230 kg of cargo, of which a maximum of 1950 kg can be propellant and a maximum of 1800 kg in equipment or supplies.


Spacecraft: Soyuz TMA.

The Soyuz-TMA version was designed for use as a lifeboat for the International Space Station. It incorporated several changes to accomodate NASA requirements, including more latitude in the height and weight of the crew and improved parachute systems. Soyuz serial number 211 was the first built to the TMA configuration, with first flight planned for March 2003.


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Last update 28 March 2001.
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