The N1-L3 - by N1 to the Moon - 1964 to 1970 Returning to 3 August 1964, Command number 655-268 issued by Central Committee of Communist Party gave Korolev the objective of putting one man on the moon and returning him safely to earth - ahead of the Americans (who had begun over three years earlier, in April 1961). To achieve this aim a large part of the industry had to be mobilised. It would require design of what was designated the L3 complex, with the combined launch vehicle/spacecraft termed the N1-L3. The L3 would utilise the same lunar orbit rendezvous method to achieve moon landing as was selected for the Apollo program. By upgrading the N1 from a 75 tonne to a 95 tonne payload capacity it was felt possible that a single N1 launch could accomplish the mission. The L3 complex itself, with a total mass of 95 tonnes, would consist of a fourth stage (Block G) for the N1 to take the L3 from low earth orbit to trans-lunar trajectory; a lunar orbiter with a Soyuz re-entry capsule for return to earth (LOK); a lunar lander (LK) for the landing of a single cosmonaut on the surface of the moon; and a deceleration stage (Block D) which would brake the L3 complex into low earth orbit and then take the LK lander to near zero velocity above the surface of the moon. The N1-L3 complex was designed not just for a quick initial moon landing, but also for exploration of the moon and near-lunar space for both scientific and military purposes. In what was only to be the first stage of a sustained campaign, single cosmonauts would land on the lunar surface. However this would be just part of a larger mission with the following objectives:
The work for the L3 project was split as follows:
The original N1 with its payload of 75 tonnes to a 300 km, 65 degree inclination orbit would require two to three launches to assemble a lunar landing expedition in earth orbit. One result of the draft project was the decision to increase the N1 payload to 95 tonnes to allow the L3 to be launched toward the moon in one launch. The following measures would increase the N1 payload to 91.5 tonnes:
Then the following measures would increase the payload to 95 tonnes:
By September 1964 construction began of the first N1 launch pad (LC110R). On October 13, while Voskhod 1 was in orbit, Khrushchev was removed from power and Brezhnev's faction assumed control of Politburo. The advance design project for the N1-L3 was completed in collaboration with Kuznetsov's OKB-586 on 30 December 1964. The decree for production of 16 shipsets of spacecraft and boosters was issued on 26 January 1965. The N1-L3 was to manufactured to the following schedule: 4 in 1966; 6 in 1967; and 6 in 1968. The plan was for the first launch of the N1 to be in the first quarter of 1966, with the first lunar landings in 1967 to 1968, ahead of the American goal of 1969. On January 14, 1966 Korolev died in Moscow during colon surgery. His successor, Mishin, did not have the forceful personality and political connections of the original Chief Designer. Korolev also had a legendary ability to motivate his staff and cajole co-operative design bureaux to prioritise work for OKB-1 that Mishin was never able to duplicate. The project continued. In February 1966 construction started of the second N1 launch pad (LC 110L). By November the first N1 hardware arrived at Baikonur and construction of the 1M1 full-size mock-up of the launch vehicle began. On 16 November 1966 another Keldysh-headed expert commission considered the state of the programme. With Korolev dead, once again Glushko, Chelomei, and Yangel advocated development of the UR-700 or R-56 in lieu of the N1. Chelomei, smarting from cancellation of his LK-1 project, offered an LK-700 direct flight manned lander in lieu of the L3. While it was agreed that engine development and studies of these alternate approaches could continue, the February 1967 government decree approved Mishin's draft plan for the first lunar landing. This integrated L1/L3 project plan indicated a landing on the moon by the end of 1968 - still ahead of the Americans. The N1 test plan envisioned third quarter 1967 as the beginning of flight hardware construction. The first N1 launch was still set for March 1968. A moon landing would not come until the third quarter of 1969 at the earliest. In February assembly of the first N1 began at the Progress plant in Samara. By the end of summer the first N1 launch pad (LC110R) was completed. Assembly of the first 1M1 mock-up was nearing completion at the MIK assembly building at Baikonur. In September 1967 the EU-28and EU-29 test models of the second and third stages began hot firing tests on their test stands at Samara. On 25 November 1967 the 1M1 mock-up was first erected on LC-110R. A decree in November had recognised yet further slips in the schedule, with a first flight test of the vehicle not expected until the third quarter 1968. By March 1968 it was recognised that no Soviet manned lunar landing would take place until 1970. On May 7, 1968, N1 booster 4L was erected at launch complex 110R. Under its shroud was the 7K-L1S spacecraft. This modification of the 7K-L1 circumlunar Soyuz incorporated the Isayev forward propulsion module that would be used on the LOK and LK. A mass model representative of the LK lander was also included. A September 1968 flight test was planned. However the first stage oxidiser tank developed cracks during ground tests, and 4L was removed from the pad in June 1968. It had to be scrapped and improvements made to 3L, the next vehicle. The first N1 countdown began in January with the roll-out of 3L to the pad. Finally, on February 21, 1969, N1 serial number 3L rose into the sky, thundering over the roofs of the assembly worker's apartments as they cheered it on. But immediately after launch a fire broke out in the tail compartment. The engine monitoring system detected the fire, but then gave an incorrect signal shutting down all engines at 68.7 seconds into the flight. The vehicle was destroyed by range safety 1.3 seconds later. The SAS escape tower worked as designed and the 7K-L1S capsule was recovered. Against this failure, the Apollo program was achieving success after success in bimonthly missions. While beating the Americans to a moon landing was now clearly impossible, a dual unmanned mission was devised, which, if successful, would have stolen a little of the American's thunder. The plan was for the next N1 to launch an unmanned 7K-L1S spacecraft on a loop around the moon. It would take multi-spectral photographs of the lunar surface and far side. Meanwhile, a Proton rocket would launch an unmanned Ye-8 soil return spacecraft. This would soft land on the moon, deploy a core drill which would take a small sample of lunar regolith. Deposited in a small spherical re-entry capsule, this then would automatically be returned to earth. N1 vehicle 5L was launched on July 3 1969, just two weeks before the Apollo 11 first moon landing. It was a catastrophe. 5L already began to fail at 0.25 second after lift-off when the oxidiser pump of engine number 8 ingested a slag fragment and exploded. A fire ensued as the vehicle climbed past the top of the tower. The KORD reacted and engines were shut down in pairs until the acceleration dropped below 1 G; then the vehicle began to fall back to the pad at a 45 degree angle. The escape tower fired at the top of the brief trajectory, taking the L1S descent module away from the pad. 5L exploded with the force of a small nuclear bomb, destroying launch complex 110R. To compound the failure, the Ye-8 robot made it to the moon but crashed onto the surface as the Apollo astronauts rested after the first moon walk. With the moon race lost, the rationale for further development of the limited 7K-LOK and LK spacecraft for a dash to the moon disappeared. However project momentum resulted in several test flights of N1-L3 hardware. These were:
By 1972 any thought of using the original N1-L3 hardware for a manned lunar mission had been abandoned. Instead it was planned to surpass the Americans after the Apollo flights were completed by establishing a lunar base. The Zvezda DLB - 1964 to 1974 It may be recalled that the N1 draft project of 1962 spoke as well of 'establishment of a lunar base and regular traffic between the earth and the moon'. Korolev raised the matter informally at tea with Chief Designer of rocket complexes Vladimir Pavlovich Barmin, head of GSKB SpetsMash (State Union Design Bureau of Special Machine-Building). Barmin was interested in pursuing the subject, but how could such a base be placed on the moon. 'You juste design the base', Korolev assured him, 'and I'll figure out how to get it there'. The project was known to SpetsMash as the 'Long-term Lunar Base' (DLB) and to OKB-1 as 'Zvezda'. Consideration was given to using the same elements in expeditions to other planets. Under the DLB studies SpetsMash defined purposes of the base, the principles of its construction, phases of its deployment and composition of its scientific and support equipment. The enthusiasts that worked on the project at Zvezda were naturally known as 'lunatics'. Zvezda would have utilised unmanned spacecraft designed by the Lavochkin OKB to conduct initial reconnaissance of the prospective moon base site. These would use lunar soil core drills to obtain samples of the soil and return them to earth for analysis, and Lunokhod rovers to survey the site. If the site was found to be satisfactory, these craft had radio beacons which would guide follow-on elements of the base to precision landings. Ambitious articulated mobile nuclear-powered Lunokhod laboratories would take the cosmonauts from the landing sites on long-duration traverses of the lunar surface. The Lunokhods were equipped with core samplers and manipulators so that the crew could conduct collection of surface samples from within the pressurised cab without the need to always exit the ship and conduct surface operations in space suits. One of the main objectives of the base would be the location and mining of Helium-3 for use in nuclear fusion reactors on earth. Rare on the earth, Helium-3 was abundant on the moon, having collected in the regolith from the solar wind. Barmin's lunar base would be crewed by nine cosmonauts and consist of nine modules. These modules would have a length of 4.5 m during launch and transport on the moon. Once position in place on the surface of the moon and inflated with air, they would telescope out to 8.6 m length with a total floor area of 22.2 square metres. Power would be provided by nuclear reactors. The nine modules would be pre-equipped in the factory for specialised functions: command module, laboratory/warehouse module, workshop module, midpoint module, medical/gymnasium module, galley module with dining room, and three living modules. A prototype of one of these modules was used in 1967 for a one-year closed-cycle living experiment at the IBMP (Institute for Bio-Medical Problems). Based on the results of this experiment it was planned that the units on the moon would have a false window, showing scenes of the Earth countryside that would change to correspond with the season back in Moscow. The exercise bicycle was equipped with a synchronised film projector, that allowed the cosmonaut to take a 'ride' out of Moscow with return. These psychological measures were felt important to maintain the crew's mental health. In later versions, the manned elements apparently used the improved L3 complex (designed for the follow-on two man lunar landings) to ferry manned crews from earth orbit to lunar orbit and then from lunar orbit to the surface and back. The Block Sr LOX/LH2 stage would be used to insert the components of Zvezda into low lunar orbit. By 1971 the lunar city project was practically complete and Chief Designer Barmin arranged a meeting with Secretary Ustinov, head of all military and space rocketry. He brought along two of this 'lunatics', Aleksandr Yegorov and Vladimir Yeliseyev. The project was defended in a marathon meeting - nine presentations over six hours. At the conclusion, Ustinov agreed that the project should go ahead - but he couldn't decide, at the pace of a walk or the speed of a freight train. In the event, the point was moot. The N1 never successfully flew, and the rocket, and its associated projects, were cancelled in May 1974. In any case, the Soviet economy very likely could never have sustained the cost of the project - 80 billion dollars in 1997 prices. Unmanned elements of Zvezda designed by the Lavochkin bureau and using lunar core sampling drills designed by Barmin flew in 1969-1976 under the 'Luna' program. Although these flights were conducted in direct reconnaissance support of a manned lunar landing and lunar base, at the time it was declared that no Soviet manned lunar landing program existed, and that these unmanned flights represented a way to achieve the results of the American Apollo program without such expense and risk to life. After a number of launch vehicle failures this series of probes had some success. Luna 15 had crashed while attempting to land on the moon while the Apollo 11 astronauts were on the surface. But on September 20, 1970 Luna 16 safely soft landed on the moon and then returned lunar soil to Soviet territory. Lunokhod 1 travelled about a small portion of the Sea of Rains and returned photographs. Luna 19 mapped the gravity field of the moon in preparation of later manned flights. Luna 20 returned to earth more lunar soil, and Lunokhod 2 roved around an area representing the transition zone between the lunar maria and the highlands. The N1M-L3M and N1F-L3M - 1970 to 1974 Concurrent with DLB studies, OKB-1 was already developing more powerful versions of the N1 to launch heavier payloads to the moon. The N1 growth study S. P. Korolev had signed shortly before his death had foreseen the wide use of oxygen-hydrogen propellants in modified versions of the N1 launch vehicle. It will be recalled that the 1965 study foresaw development of a Block V-II Lox/LH2 replacement for the Block B second stage of the N1. At OKB-276 N. D. Kuznetsov led a project to develop a liquid oxygen/liquid hydrogen version of the NK-15V engine with a flight thrust of 200 tonnes for use in this modernised version of the second stage of the N1. However Kuznetsov was having enough difficulty in completing satisfactory development of the conventional version of this engine for use in the basic N1 and his 200 tonne engine did not reach the hot firing test stage. While these more ambitious plans would not be realised, the collectives OKB-2 (A. M. Isayev) and OKB-165 (A. M. Lyulka) were continuing studies and basic development that had begun in 1961. The first Russian use of hydrogen as a fuel was planned for rocket stages of relatively small size (with up to 50 tonnes of fuel). These stages, which were designated Block S and Block R, were to be introduced in place of N1 Blocks G and D as part of a modernised L3M lunar spacecraft complex. Use of oxygen-hydrogen propellants would permit expeditions to the moon of three crew, of which two would walk on the surface of the moon. Isayev set about adapting the 11D56 engine, with a vacuum thrust of 7.5 tonnes, for the Block R. This engine had originally been designed in the early 1960's for use in the third stage of an uprated Molniya-L launch vehicle. The new Block R for the N1 was to have an empty mass of 4.3 tonnes, a maximum fuel load of 18.7 tonnes, and would have been 8.7 m long and 4.1 m in diameter. Lyulka developed two variants of a 40 tonne engine - the 11D54 (with fixed chamber) and 11D57 (with gimballed chamber). These would be used for the new Block V-III third stage of the N1 (3 to 6 11D54) and in the Block S (one 11D57). First hot firings of the 11D56 on the test stand began in June 1967. Both the 11D56 and 11D57 engines successfully completed their state development test series. At the Tsniimash museum in Korolev a photograph is displayed of a dynamic test model of an N1 configuration that has been called N1M. This model shows an N1 first stage, with a Block V-III second stage, and Blocks S and R third and fourth stages. Calculations indicate that a two stage Block A / Block V-III N1 would have a low earth orbit payload comparable to that of the basic N1 (around 95 tonnes). Evidently this configuration was considered as an alternative to a conventional three stage N1 for launching the L3M complex into low earth orbit. The original draft project for the new N1M-L3M lunar landing complex anticipated use of a two-launch profile. On the first launch a Block R RTB braking stage would be put on a translunar trajectory. The RTB 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 RTB stage in lunar orbit. The RTB would act as a lunar crasher stage. The L3M would separate from the RTB 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. At least two drawings of varying designs for the L3M have emerged to date. In one, 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. This probably represents the original N1M-L3M variant. 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. With the cancellation of the N1 in 1974, work on the upper stages and spacecraft for lunar expeditions did not end. The designs were simply modified for use on the replacement launch vehicle, the Vulkan. The Vulkan LEK - 1974 to 1976 Although the N1, L3, and Zvezda projects were cancelled, Glushko still considered the establishment of a moon base to be a primary goal for his country. While the Americans had achieved the first moon landing, it was known that all moon flights after Apollo 17 had been cancelled. There existed an opportunity, through establishment of a permanent moon base, to steal the lead in the space race once again. Furthermore, analysis of the results of the previous unmanned and manned indicated that the moon was suited for a variety of 'special investigations', and that a permanent lunar expeditionary complex (LEK) would be required to accomplish this. To launch the elements of the LEK, Glushko designed a new launch vehicle, the Vulkan. The Vulkan would use the LOX/LH2 engine technology developed for the US Space Shuttle in the core stage. This would be surrounded by six strap-on boosters, using LOX/Kerosene engines, to be developed by NPO Yuzhnoye in the Ukraine. This use of cryogenic propellants represented a complete turnaround for Glushko, who had advocated use of storable but toxic rocket propellants in a bitter fight with Korolev and Mishin for fifteen years. The Vulkan was designed to deliver 230 tonnes into a 200 km low earth orbit; 60 tonnes to lunar orbit; and 22 tonnes to the lunar surface. The LEK consisted of expeditionary and transport lunar spacecraft (Chief Designer K D Bushchev) and equipment for the permanent base station (Chief Designer I S Prudnikov). The expeditionary and transport craft consisted of:
The equipment of the permanent base station consisted of:
Delivery of the components of the LEK would be in three stages:
The LEK study and initial Vulkan design were completed by the end of 1975. However the Academy of Sciences Expert Commission decided that the LEK Project should be deferred into the next century. Soon thereafter all of NPO Energia's efforts were directed to support development of the reusable launch vehicle Energia/Buran. The Energia LEK - 1976 to 1978 A modified version of the LEK was proposed in the 1980's using the Energia launch vehicle. Because of the much lower payload capability of the Energia (88 tonnes to low earth orbit versus the 230 tonnes of the Vulkan) this would use a new LOK lunar orbital spacecraft (unrelated to the earlier Soyuz-based LOK) and an LK lander based on the Vulkan LEK lander. The LOK and LK lander would be inserted into lunar orbit by separate Energia launches. As in the earlier projects, prior to the Energia launches 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. 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. This proposal did not attract support and further development of the concept was not continued. Thus, with a whimper, ended manned lunar base studies in Russia. References
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