Soviet Manned Lunar Projects Part 1

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Soviet Manned Lunar Projects Part 1

Soviet Lunar Landers
Comparison of Soviet lunar lander designs. Only the LK reached the hardware stage.

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The First Lunar Projects - 1956 to 1959
The L1 - by R-7 around the Moon - 1959 to 1963
The L1, L2, L3, L4, L5 - by N1 to the Moon - 1960 to 1963
The Lunar Decision - 1964
The LK-1 - by UR-500K around the Moon - 1964 to 1965
The 7K-L1 - by UR-500K around the Moon - 1966 to 1970
The N1-L3 - by N1 to the Moon - 1964 to 1970
The Zvezda DLB - 1964 to 1974
The N1F-L3M - 1970 to 1974
The Vulkan LEK - 1974 to 1976
The Energia LEK - 1976 to 1978

The First Lunar Projects

The first official plan for future Soviet spaceflight was contained in a decree of 30 January 1956. This set forth the following objectives:

Orbiting of satellites of 1.8 to 2.5 tonnes mass by 1958
One week flight of a manned spacecraft by 1964
Unmanned reconnaissance satellite by 1970
Rocket capable of 12 tonne escape velocity payload by 1970
Rocket with 100 tonne low earth orbit payload, capable of placing 2 to 3 men on the moon (no date set)

The first approach to the rather vague last objective was to use nuclear power - a nuclear reactor heating ammonia propellant. Korolev's OKB-1 completed a draft project for three variants of rockets using such a propulsion system. The third variant designed was a 'Super Rocket' with a lift-off mass of 2,000 tonnes and a payload of 150 tonnes. This was a true antecedent of the later N1 moon rocket. The first and second stages were in the conical 'raketov' form later adopted for the N1. The first stage used a massive cluster of Kuznetsov NK-9 engines each with a thrust of 52 tonnes. The second stage used four nuclear engines with a total thrust of 850 tonnes. Operating at a temperature of 3500 degrees K a specific impulse of 550 seconds in vacuum using ammonia propellant was expected. A mixture of liquid hydrogen and methane was considered as a better-performance propellant at a later date. Although ideal for use in nuclear rockets, use of liquid hydrogen as a propellant was not considered technically possible in the short term.

L1-1963 - Cutaway view of 1963 L1 circumlunar spacecraft.

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Work on this form of nuclear propulsion was abandoned at the end of 1959 when it became apparent that conventional chemical propulsion could provide nearly equivalent performance with less development, safety, and environmental risk.

The L1 - by R-7 to the Moon - 1959 to 1963

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 be at an early date and 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 of OKB-256 and Solovyev of OKB-1 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'.

L2-1963 - 1963 L2 robot lunar rover spacecraft. L2 configuration speculative based on early Ye-8 rover design studies at OKB-1.

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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. The government decree 715-296 of 23 June 1960 'On the Production of Various Launch Vehicles, Satellites, Spacecraft for the Military Space Forces in 1960-1967' included authorisation for Korolev to develop draft projects on themes KS (heavy manned spacecraft, 2-3 crew, to demonstrate rendezvous, docking, and controlled flight, to be developed in 1961 to 1963) and KL (manned spacecraft for lunar flyby - to be developed in 1961 to 1964). The work was therefore upgraded to a project sector, under the leadership of Timchenko, in 1961.

L3 -1963 - 1963 L3 manned lunar lander using earth-orbit rendezvous method. Configuration based on description and lander configuration of early L3M design.

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The 1960 studies considered various configurations of ballistic capsule, 'Utka' winged schemes of conventional aircraft layout, and tail-less hybrid configurations. 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 accuracies 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.

L4 -1963 - 1963 L4 manned lunar orbiter.

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Section 11 had conceived of the modular scheme to reduce the mass of the re-entry vehicle in 1960. This was dubbed 'Soyuz'. Section 9's competing design, 'Sever' was two modules, like Apollo. Further iterative studies in 1961 to 1962 reached the conclusion that the Soyuz should consist of four sections. Use of this approach would result in a re-entry capsule 50% smaller than Sever. From fore to aft these modules 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).

L5 -1963 - 1963 L5 manned lunar rover. Drawing based on model at Tsniimash museum.

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

Put all systems and space not necessary for re-entry and recovery outside of the re-entry vehicle, into a separate jettisonable 'living module', joined to the re-entry vehicle by a hatch. Every gram saved in this way saved two or more grams in overall spacecraft mass - for it did not need to be protected by heat shields, supported by parachutes, or braked on landing. As a bonus the living module provided an airlock for exit into space and a mounting area for rendezvous electronics.
Use a re-entry vehicle of the highest possible volumetric efficiency (internal volume divided by hull area). Theoretically this would be a sphere. But re-entry from lunar distances required that the capsule be able to bank a little, to generate lift and 'fly' a bit. This was needed to reduce the G forces on the crew to tolerable levels. Such a manoeuvre is impossible with a spherical capsule. After considerable study, the optimum shape was found to be the Soyuz 'headlight'.

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 provided the same crew with nine cubic meters of living space, an airlock, and the equipment module for the mass of the Apollo capsule alone!

N1-L3 Tower - Detail of tower of N1-L3 7L

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The modular concept was also inherently adaptable. By changing the fuel load in the equipment 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 30 years later, while the Apollo was quickly abandoned.

Although only Korolev was authorised to do draft project work on lunar themes, the other Chief Designers pursued alternate approaches. Chelomei was Korolev's arch-rival, and had the advantage of having Nikita Khrushchev's son in his employ. He was said to have been ordered informally by Khrushchev on 13 May 1961 to begin development of a manned circumlunar spacecraft in response to the American Apollo program. This would be launched by his UR-500 rocket, already being designed as authorised in the same June 1960 decree that started work on Soyuz. The advantage of using the UR-500 was that a manned spacecraft could be launched around the moon in a single launch, as opposed to the complex earth-orbit assembly techniques being refined by Korolev. Funds for design work on the LK-1 were available from the Kosmoplan and Raketoplan projects. These were lifting-body unmanned and manned vehicles being designed by Chelomei for a range of military and planetary exploration missions as per the June 1960 decree.

The first 1961 draft of the Soyuz project (codes KS, KL, and Vostok-Zh of the 1960 decree) would exploit the modernised Vostok-Zh. Three rocket stages would be assembled in low earth orbit using a manned Vostok tug. They would then launch a Soyuz capsule on a lunar flyby and return to earth.

N1 engineers - N1 engineers study drawing

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In the definitive December 1962 Soyuz draft project, the Vostok was gone and Soyuz A appeared as complete two-place spacecraft. The project 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 9K tanker block. This would be followed by three or four 11K tankers, 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.

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 7K: the Soyuz-P space interceptor and the Soyuz-R command-reconnaissance spacecraft. The VVS and the rocket forces supported these improved variants of the Soyuz.

To Korolev's frustration, while Kozlov's OKB-1 Filial 3 in Samara received budget to develop the military Soyuz versions, his own circumlunar Soyuz-A was not included in the space program of the USSR. The 7K-9K-11K plan would have required five successful automatic dockings to succeed. This seemed impossible at the time. Chelomei's LK-1 single-manned spacecraft, to be placed on a translunar trajectory in a single launch of his UR-500K rocket, was still the preferred approach. But even Chelomei had no official authorisation to undertake actual detailed design and development of the spacecraft or booster.

N1 Engine fired - N1 Engine fired on test stand

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The L1, L2, L3, L4, L5 - by N1 to the Moon - 1960 to 1963

Even while attempting to obtain approval for his modest R-7-launched L1 circumlunar spacecraft, Korolev was attempting to sell more ambitious schemes using his N1 super-rocket. The space race with the Americans had heated up considerably since the promulgation of the casual program of 1956. 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 development 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.

This letter was followed by a meeting with Khrushchev on the subject on 3 March 1960. Korolev believed it would be truly possible with backing from the very top to have a large rocket in the USSR in a very short span of time. Unfortunately at the meeting Korolev made a slip of the tongue he would always regret, admitting that his plan had not been agreed among all of the Chief Designers. This resulted in Khrushchev throwing the matter back for a consensus plan.

N1 Upper Stage - N1 Upper Stage firing on test stand

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By 30 May 1960 Korolev was back with a plan that now included participation of his rivals, Chelomei and Yangel. But Korolev had managed to retain the lunar work. The consolidated plan included the following lunar elements relating to the program of lunar exploration:

N-I - (Korolev) - to be developed in 1960 - 1962. 40 to 50 tonnes payload to low earth orbit and 10 to 20 tonnes to Mars. Draft project to be completed by second quarter 1961.
N-II - (Korolev) - to be completed in 1963 - 1967. 60 to 80 tonne payload to low earth orbit and 20 to 40 tonnes to Mars. Draft project to be completed in 1962.
KS - (Korolev) - Heavy manned spacecraft, 2-3 crew, to demonstrate rendezvous, docking, and controlled flight. To be developed in 1961 to 1963 (this would become Soyuz).
KL - (Korolev) - Manned spacecraft for lunar flyby. To be developed in 1961 to 1964 (this would become the L1).
Vostok recoverable spacecraft (Korolev) - Manoeuvrable rendezvous and docking version to be developed in 1961 to 1963 (this was the Vostok-Zh - never flown, replaced by Soyuz)
R-7 - Four-stage version of R-7- (Korolev) - 300 tonne gross lift-off mass, available from 1960 for robotic lunar and interplanetary flights (this would be the Molniya booster)
R-7L - (Korolev) - Develop in 1960 to 1962 a 4 stage version of the R-7, utilising R-9 technology, with a 300 tonne gross lift-off mass and high specific impulse engines in the last stage. Payload 10 tonnes to low earth orbit and 3 tonnes to escape. Draft project to be completed in 1961 (this booster, later called the Molniya-L, was never developed).
E - (Korolev) - Launch to the moon (as per decree of 10 December 1959) E-1 lander probes in 1960 to 1961 and E-7 orbiters in 1961 (these lunar probes would eventually succeed many years behind schedule)
N1 6L Liftoff
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UR-500 - (Chelomei) - Develop a 600 tonne gross lift-off mass rocket using new chemical propellants for sending spacecraft to nearby planets. Draft project to be completed in 1962. (This would become the UR-500 Proton booster - the later launch vehicle for the LK-1)
K - (Chelomei) - Development of unpiloted Kosmoplans for flight to Mars and Venus with return to earth and landing at conventional airfields. These would use new exotic chemical systems, low thrust nuclear engines (nuclear-plasma, ion, atomic hydrogen). Sub-variants with a total mass of 10 to 12 tonnes and 25 tonnes would be developed in 1965-1966. Draft project to be completed in 1962. (Chelomei would expand this Kosmoplan concept to include lunar probes as well).
R - (Chelomei) - Manned Raketoplan spacecraft for orbital manoeuvring flight and recovery at conventional airfields. Total mass to be 10 to 12 tonnes, total gliding range during re-entry 2,500 to 3,000 km. Unpiloted version to be developed in 1960 to 1961, followed by piloted version in 1963 to 1965. Satellite interceptor operational version to be tested in 1962 to 1964 (Chelomei would later expand Raketoplan to a wide range of tasks, including manned lunar flyby and landing. The LK-1 manned circumlunar spacecraft would be designed under this heading).

Note that although completion of draft projects for the N1 and L1 were authorised, no work on a N1-launched lunar landing or lunar orbiter spacecraft was included. Therefore only N-I and L1 design work officially began as a result of the final government decree 715-296 of 23 June 1960 'On the Production of Various Launch Vehicles, Satellites, Spacecraft for the Military Space Forces in 1960-1967'.

N1 6L ignition

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By September 1960 Korolev's engineers had already settled on the N1 configuration they would defend formally in the review of the draft project nearly two years later: a monoblock 'carcass' scheme with a total lift-off mass of 2,000 tonnes and a payload of 70 to 75 tonnes.

Although only Korolev was authorised to do draft project work on lunar themes, the other Chief Designers pursued other approaches. Aside from Chelomei's LK-1 circumlunar spacecraft, the Yangel and Chelomei bureaux developed alternate booster designs (Yangel's was designated R-56 and Chelomei's was the UR-700). Both used clustered 4 m diameter rocket stages, equipped with a single large Glushko engine, using toxic storable propellants, with a thrust of 450 to 550 tonnes. Such stages could be built in factories in Moscow or Dniepropetrovsk and shipped on the existing Soviet rail system to Baikonur for final assembly.

The N-I draft project was completed on 16 May 1962. The design was defended before the other Chief Designers on 2 to 16 July 1962. Among the design objectives of the three stage N-I were:

Circumnavigation of the moon with a crew of two to three men; entry into lunar orbit of robotic and crewed modules for study of the lunar surface
Expeditions to the surface of the moon for the study of its soil, relief, inner structure, physical properties, and selection of a suitable site for a research base on the moon
Establishment of a lunar base and regular traffic between the earth and the moon;

N1 6L Engine Start

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After extensive study it was determined that the design objective of a single launch payload of 75 tonnes into a 300 km orbit best met the required payload masses for a variety of missions, among them a manned lunar orbiter and a manned lunar landing (if used with Lox/LH2 upper stages).

The expert commission supported the draft project. But the programme was still without an authorised mission. At a meeting between Khrushchev and the Chief Designers at Pitsunda in August, Khrushchev ordered start of a project to put a 75 tonne manned platform with nuclear weapons into low earth orbit. This was the initial payload; the official decree authorising N-I production was issued on 24 September 1962 with first flight to occur in 1965. After two years of struggle, Korolev finally had his authorisation to build a moon rocket - but not a spacecraft for it.

This did not stop Korolev from fleshing out the ambitious lunar plans set out in the draft project and trying again for approval. On 23 September 1963 Korolev submitted his plans for space projects in the period 1965 to 1975. He now saw a clear chance to again appeal to the leadership for a manned lunar landing program. He dusted off his rejected L-1 circumlunar project, and added four new spacecraft that would allow reconnaissance, followed by landing on the moon and extended exploration of its surface.

N1 7L Liftoff

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The first two projects, as before, would use R-7 based launch vehicles and extensive docking and refuelling operations in low earth orbit. But elements of these would be used in the last three, which would map the moon from lunar orbit, land men on its surface, and explore it with a manned crawler.

L-1

This revision to the original L1 project of 1962 had the same objective of sending two men on a circumlunar flyby trajectory. But now the Soyuz had a reverse configuration of that used earlier. From fore to aft, the modules were: the Descent Capsule (SA), Living Module (BO); Equipment Module (AO); Propulsion Module (AO); Rendezvous electronics module (NO) and Docking Unit (SU). This configuration would be important in the later N1-based projects. As before, the system consisted of the 7K manned spacecraft, the 9K rocket spacecraft, and the 11K tanker. A total of six launches of the 11A511 Soyuz booster would be required. The 9K rocket stage would be put in orbit first. It would be followed by four 11K tankers which would top off the tanks of the rocket block. Then, when all was ready, the 7K manned craft would be put into orbit and dock with the 9K stage. The stage would fire and put the manned spacecraft on a translunar trajectory.

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.

N1 MIK Assembly Hall

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L-2

The L2 was a project to land a remote-controlled self-propelled rover on the surface of the moon. It would use the same rocket stage and tanker elements developed for the L1 manned circumlunar project. It can be seen to be the direct ancestor of the Ye-8 Lunokhod lunar rovers of the 1970's.

The objective of the L-2 would be to conduct scientific research on the lunar surface and to allow selection of a favourable landing point for later manned flights. A television system would send back panoramic television pictures. The rover would be nuclear-powered and equipped with a radio beacon for later manned expeditions to home on for precision landings. It would also investigate:

The relief of the lunar surface
The mechanical properties of the lunar soil
The microscopic structure of the surface
The magnetic fields of the moon
Cosmic ray flux
Solar insolation at the surface

The L-2 system consisted of:

The L-2 crawler. This had a maximum speed of 4 km/hour and a range of 2,500 km. The L-2 consisted of:
- Motor compartment with equipment permitting speeds of up to 4 km/hour
- Equipment compartment, with on-board radio, navigation, and control systems
- Power generating system (evidently solar and/or radioisotope generators)
The 13K rocket system for midcourse corrections and lunar braking. This would brake the L-2 to a direct landing on the surface of the moon with no intermediate lunar orbit. It consisted:
N1 Model Test
Credit: RKK Energia. 13,560 bytes. 306 x 236 pixels.
- Braking stage, for midcourse corrections and the main braking impulse for the landing on the surface. This would ignite at an altitude of 200-300 km above the surface.
- The landing vehicle, with throttled engines, for the soft landing on the surface at a speed of only 2 to 4 m/s.
- The guidance system
- The manoeuvring and guidance system for docking with the 9K in earth orbit, which was cast off before the translunar injection.
The 9K translunar injection stage for sending the L-2 towards the moon from the low earth assembly orbit. This was the Soyuz B rocket stage used on the L-1 project

Total mass of the L-2 + 13K + 9K complex at ignition of the 9K for translunar injection was 23,000 kg. Total mass of the L-2 and 13K in their translunar cruise configuration was 5,000 kg. As was the case for the L-1, six launches of the Soyuz 11A511 booster would be required to assemble the L-2 in a 225 km low earth assembly orbit.

L-3

Korolev's first version of the L-3 manned spacecraft 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. The L3 spacecraft thereby assembled consisted of:

N1 Wind Tunnel Test

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Translunar injection stage, with a total mass of 138 tonnes
The lunar braking stage, which included a separate midcourse correction section cast off before the braking burn. Midcourse manoeuvres would be made at 100,000 and 150,000 km from the earth to ensure a landing near the site pre-surveyed by the L-2 robotic lunar rover, which would be providing a homing signal for the L-3. The lunar braking stage had a total mass of just under 40 tonnes. The main braking burn would start 200 to 300 km above the surface.
The lunar soft landing/ascent stage, which had a total mass of 21 tonnes landed on the moon. The stage would use variable-thrust engines to make a soft landing at 2-4 m/s on the surface. The landing leg structure and soft landing engines would be left behind on the moon.
The ascent stage, which would separate from the landing legs and propel the manned capsule back toward the earth. This included the guidance system for the entire L-3 complex.
The Soyuz L1 manned spacecraft, which consisted of a 2.5 tonne equipment module and 2.5 tonne re-entry module. It could accommodate a crew of two to three.

The total L3 mission would take ten to seventeen days. 2.5 to 3.5 days would be spent on the translunar and transearth legs of the mission Five to ten days would be spent on the lunar surface.

The L3 was not authorised in this form and it would over two years before a very belated start was made to beat the Americans in the moon-landing race. The L3 reformulated for the crash program would require only a single uprated N1 launch and use the lunar-orbit-rendezvous method, with a single-man lander.

N1 Subscale Model

Credit: RKK Energia. 22,171 bytes. 338 x 240 pixels.

L-4

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. 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.

L-5

The L-5 Heavy Lunar Self-Propelled Craft would be used for extended manned reconnaissance of the lunar surface. 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.

Translunar injection stage, with a total mass of 64 tonnes
The lunar braking stage, which included a separate midcourse correction section cast off before the braking burn. The lunar braking stage had a total mass of just under 14 tonnes. The main braking burn would start 200 to 300 km above the surface.
The lunar soft landing/ascent stage, which had a mass of 1.3 tonnes landed on the moon. Presumably the stage would make a precision landing, homing on a beacon provided by an L-2 robot scout. The stage would use variable-thrust engines to make a soft landing at 2-4 m/s on the surface.
The L-5 rover, with a mass of 5.5 tonnes

Model of N1 pad

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The Lunar Decision - 1964

At the beginning of 1964, despite hard work in the previous year, it was apparent that there were still one to two years of development and construction to go and the target dates set in the decree would not be met.

On 24 March 1964 Korolev managed another meeting with Khrushchev, where he again advocated an aggressive plan of lunar and interplanetary exploration. He dusted off his old L3 lunar landing scheme. Two variants of the L3 would be developed: the basic version would use Lox and Kerosene in Rocket Blocks G and D, with N2O4/UDMH in Block E. A later version would use Lox/LH2 in all of these upper stages. This would add 4 tonnes to the lunar surface payload. Korolev promised to have an L3 draft proposal completed in 1964 and the spacecraft in service by 1966. Development of the Lox/LH2 engines would take place from 1964 to 1967. He even pressed development of the TMK / TMK-E interplanetary manned spacecraft, using the newest designs from his bureau with nuclear electric engines. Khrushchev expressed some interest now in the lunar landing scheme, in the face of the American's evident determination to press on with project Apollo.

Feeling he had Khrushchev's support, Korolev on 25 May 1964 drafted a letter to Brezhnev, then in charge of missile development. Korolev complained of the delays in the N-I due to lack of priority and financing. He noted that of 11 million roubles budgeted for construction of the launch complex in1964, only 7 million had been received. Two years after authorisation ,work on the guidance systems had not even begun, due to the priority of military projects. Korolev tried to put the screws to Brezhnev by noting that Khrushchev had always sponsored scientific projects, and that with the Saturn I rocket the Americans had already surpassed the Americans in the booster race. He also attempted to sabotage Chelomei's LK-1 circumlunar project yet again, by noting that he was wasting his time with Glushko's 'low energy' propellants and that a single launch of his N-II could put a Soyuz modification on the same mission.

N1 Rollout - N1 Rollout - base of booster

Credit: RKK Energia. 24,422 bytes. 341 x 239 pixels.

It is not clear if this letter was sent; and if so, it certainly hurt Korolev with Brezhnev when he would ascend to power in a year's time. But he had convinced Khrushchev of the necessity for a high priority lunar landing project to beat the Americans. But he wouldn't get the whole mission, either. Chelomei managed to get his UR-500K/LK-1 circumlunar project authorised - in parallel with Korolev's N1-L3.

The LK-1 - by UR-500K around the Moon - 1964 to 1965

On 3 August 1964 Command number 655-268 issued by Central Committee of Communist Party authorised both Chelomei and Korolev to proceed with development and production of their respective moon projects.

Chelomei was permitted to develop his three-stage UR-500K launch vehicle and the LK-1 circumlunar spacecraft. Thanks to the informal work done in the years before, the advanced design was already completed. 12 LK-1's were to be built in 1965 to 1966 with first flight in 1967.

The capsule had the same shape as the US Apollo capsule, but was much smaller (2.8 m diameter vs. 3.9 m for Apollo). The 17 tonne LK-1 would be into a parking orbit of the earth by the UR-500K launch vehicle. The rocket engine of the LK-1 itself would put it on a translunar trajectory and perform necessary midcourse corrections.

Then on October 13, 1964, only two months after the project, Khrushchev was removed from power and Brezhnev's faction assumed control of Politburo. This immediately led to a shift of political forces. Chelomei lost his main patron and Korolev immediately again attempted to gain control of the manned circumlunar project. Many of Chelomei's pet projects, such as the Raketoplan, the Kosmoplan, and the UR-200 booster, were cancelled. But following review by an expert commission headed by Keldysh, the LK-1 and UR-500K were permitted to continue.

N1 Rollout - N1 Rollout - view from inside MIK

Credit: RKK Energia. 17,840 bytes. 306 x 240 pixels.

The 7K-L1 - 1965 to 1970

While he had not been able to obtain approval to begin development of his Soyuz A circumlunar spacecraft, work on the Soyuz 7K-OK earth orbital spacecraft was authorised in a decree of 3 December 1963. Korolev continued work on the 7K-OK while covertly developing a 7K-L1 circumlunar version. By mid-summer 1965 Korolev noted that while development of the Soyuz was proceeding on schedule, Chelomei's LK-1 was badly lagging behind (although the Proton booster was on schedule). On 25 August 1965 a knock-down-drag-out meeting was held between Ustinov and the Chief Designers. Although he was received as much criticism as he gave, Korolev's hand can be seen in supporting the elimination of duplicate projects (such as Chelomei's LK-1). Ustinov compared the mounting successes of the American space projects with the continuing delays and failures of the Soviet projects. The problems were clearly gross underfunding of the entire programme and duplication of effort between the Chief Designers. The Chief Designers fought bitterly but would not back down. But it was finally clear to the leadership that some drastic reorganisation was required to keep up in the space race. Korolev could see that he would soon have the whole thing under his control.

On 25 October 1965, Korolev regained the project for manned circumlunar flight. Chelomei's LK-1 spacecraft was cancelled. In its place, Korolev proposed to use a combination of Chelomei's UR-500K booster, Korolev's Block D stage being developed for the N1-L3, and the Soyuz 7K-L1.

The resulting L1 was officially developed according to the decrees of 3 August 1964 and 25 October 1965. It consisted of the 11S824 Block D rocket stage, the 11F91 7K-L1 spacecraft, and the Block L-1 SAS (launch escape system). The UR-500K rocket would boost the L1 to suborbital velocity. Then the L1, with a total mass of 27.5 tonnes, would ignite its Block D stage. The Block D burned for 160 seconds the first time, placing the complex into an earth parking orbit. At translunar injection, total mass was 18.2 tonnes. After burnout of the Block D, it would separate and the 5.7 tonne 7K-L1 would accomplish necessary midcourse trajectory corrections using its own engine.

The Block D was derived from the N1-L3 moon landing braking stage. The spherical liquid oxygen oxidiser tank was of titanium and was enclosed by thermal insulation blankets. The toroidal kerosene fuel tank was also of titanium. The 11D58 engine had a thrust of 8.5 tonnes and a specific impulse of 349 seconds. It was derived from the 8D726 rocket engine of the 8K713 GR-1 Global Rocket, which itself was derive from the S1.5400 Block L of the 8K78 Molniya launch vehicle.

The 7K-L1 was a modified Soyuz 7K-OK. The forward living module was deleted. Special on-board systems were added for interplanetary navigation. The SAS launch escape system could pull the spacecraft away from the failing booster up to the point of second stage ignition. It is interesting to note that the reserve parachute was deleted in order to add an exit hatch in the side of the re-entry capsule. Originally Korolev considered that the 7K-L1, for either safety or mass reasons, could not be boosted directly by the UR-500K toward the moon. Therefore he envisioned launch of the unmanned 7K-L1 into low earth orbit, followed by launch and docking of a three man 7K-OK with the L1. Two cosmonauts would then transfer to the L1 through the side hatch. The 7K-OK, with one cosmonaut remaining, would separate and return to earth. The two cosmonauts in the 7K-L1 would then be boosted toward the moon. Development of the L1 began in November 1965.

While a victory for Korolev, it was an added project at a time that the N1-L3 was in serious technical and schedule problems. Korolev had begun to admit to his colleagues that the moon landing could not come until 1969 at the earliest.

On January 14, 1966, only three months after taking control of the L1 project, Korolev died in Moscow during colon surgery. He had kept his illness a secret from his colleagues and his death at 56 came as a surprise to many. There were delays in appointing a successor. After Kozlov in Samara turned down the job it finally went to Korolev's deputy, Mishin. But during the course of 1966, building on the work already done on the 7K-OK, drawing release and fabrication of the 7K-L1 spacecraft went ahead with astonishing speed. In February 1967 the government approved an integrated L1/L3 project plans indicating a first manned L1 circumlunar mission as early as June 1967.

The L1 would fly, but it would not succeed in putting a Soviet citizen around the moon. To briefly summarise the flights of the L1 project:

1967-03-10: Cosmos 146 - Soyuz 7K-L1P s/n 2P - Prototype Soyuz 7K-L1P launched by Proton into planned highly elliptical earth orbit. The first flight four-stage Proton rocket began assembly on 21 November 1966, with mechanical assembly completed by 29 November. Electrical connections and tests were completed by 4 December 1966. Due to New Year's holidays work did not resume until 28 January 1967. By 28 February the fully assembled booster / spacecraft unit was completed in the MIK, including the 7K-L1P boilerplate spacecraft. The launch tower was added on 2 March 1967 and the system was declared ready for launch. A serious potential problem during preparations was the discovery that fuel gases could lead to pump cavitation at the turbine exits. Tests on the ground showed that the problem was not the fuel itself, but in the monitoring equipment. The launch vehicle and Block D stage functioned correctly and put the spacecraft into a translunar trajectory. The spacecraft was not aimed at the moon, did not have a heat shield for re-entry, and no recovery of was planned or attempted. A successful launch that created false confidence just before the string of failures that would follow.
1967-04-08: Cosmos 154 - Soyuz 7K-L1P s/n 3P - Prototype Soyuz 7K-L1 manned circumlunar spacecraft. Reached earth orbit but Block D translunar injection stage failed to fire (ullage rockets, which had to fire to settle propellants in tanks before main engine fired, were jettisoned prematurely). Spacecraft burned up two days later when orbit decayed.
1967-05-17: Cosmos 159 - E-6LS s/n 111 - This high-earth orbit radio-equipped version of the E-6 lunar probe was used to test tracking and communications networks for the Soviet manned lunar program.
1967-09-27: Soyuz 7K-L1 s/n 4L - First attempted circumlunar flight. The booster crashed 65 km from the pad, but the launch escape system functioned correctly and the spacecraft was recovered.
1967-11-22: Soyuz 7K-L1 s/n 5L - Second attempted circumlunar flight. Four seconds after second stage ignition the booster went out of control. The launch escape system shut down the engines and the escape tower pulled the spacecraft away from the booster. The Proton crashed 300 km from the pad and the Soyuz was recovered 80 km southwest of Dzhezkazgan.
1968-02-07: E-6LS s/n 112 - Radio-equipped version of the E-6 lunar probe intended to test tracking and communications networks for the Soviet manned lunar program. Failed to reach orbit due to failure of Molniya launch vehicle third stage.
1968-03-02: Zond 4 - Soyuz 7K-L1 s/n 6L - Spacecraft successfully launched into 330,000 km apogee orbit 180 degrees away from the moon. On re-entry, the guidance system failed, and the planned double skip manoeuvre to bring the descent module to a landing in the Soviet Union was not possible. Ustinov ordered the self-destruct package to be set off and the capsule blew up 12 km above the Gulf of Guinea. Kamanin disagreed strongly with this decision; the spacecraft could have still been recovered in the secondary area by Soviet naval vessels after a 20 G re-entry. The decision was made to recover the spacecraft in the future whenever possible.
1968-04-22: Soyuz 7K-L1 s/n 7L - A short circuit in the malfunction detection system led the launch escape system to believe incorrectly that a launch vehicle failure had occurred. It commanded shut down of the second stage engines 260 seconds in the flight, and the escape tower pulled the Zond away from the booster, for a safe recovery.
1968-07-21: Zond 7K-L1 s/n 8L - The Block D stage exploded on pad, killing three people. Booster and 7K-L1 spacecraft were still intact however.
1968-09-15: Zond 5 - Soyuz 7K-L1 s/n 9L - First successful circumlunar flight with recovery. Like Zond 4, the re-entry guidance system failed. However this time the self destruct command was not given. After a ballistic 20G re-entry the capsule splashed down in the Indian Ocean at 32:63 S, 65:55 E. Soviet naval vessels were 100 km from the landing location and recovered the spacecraft the next day, shipping it via Bombay back to Soviet Union.
1968-11-10: Zond 6 - Soyuz 7K-L1 s/n 12L - Successfully launched towards the moon. A midcourse correction on 12 November resulted in a loop around the moon at an altitude of 2,400 km on 14 November. Zond 6 took spectacular photos of the moon's limb with the earth in the background. On the return leg a gasket failed, leading to cabin depressurisation, which would have been fatal to a human crew. The 7K-L1 then made the first successful double skip trajectory, dipping into the earth's atmosphere over Antarctica, slowing from 11 km/sec to suborbital velocity, then skipping back out into space before making a final re-entry onto Soviet territory. After the re-entry the main parachute ejected prematurely, ripping the main canopy, leading to the capsule being destroyed on impact with the ground. The photos were recovered and a small victory obtained over the Americans. But the criteria for a manned flight had obviously not been met and Mishin's only hope to beet the Americans was a failure or delay in the Apollo 8 flight set for December. The next Zond test was set for January.
1969-01-20: Soyuz 7K-L1 s/n 13L - Apollo 8 successfully conducted the first manned lunar orbital mission at the end of December, 1968. However the scheduled next 7K-L1 test flight went ahead as scheduled. However a launch vehicle second stage engine failed at 510 seconds into the mission, leading to an automatic booster shutdown. The abort system again functioned perfectly, taking the capsule to a safe landing (in Mongolia!). 7K-L1 activity was now stopped while effort turned to launching a Ye-8 unmanned soil return vehicle and N-1.
1969-08-08: Zond 7 - Soyuz 7K-L1 s/n 11L - Circumlunar flight; successfully recovered in USSR August 13, 1969. Only completely successful L1 flight that could have returned cosmonauts alive or uninjured to earth. Landed 50 km from aim point near Kustani in the USSR.
1970-10-20: Zond 8 - Soyuz 7K-L1 s/n 14L - Lunar flyby; successfully recovered October 26, 1970. Final circumlunar flight. Again re-entry guidance system failed - 20 G ballistic re-entry followed by splashdown in Indian Ocean.
1970-10-31: Soyuz 7K-L1 s/n 10L and 15L - Manned circumlunar missions using the remaining two L1 capsules were possible, but the project was cancelled.

As can be seen, 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.

Continued in Part 2.

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Last update 12 March 2001.
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