Prelude: Birth of a Giant
"I believe that this Nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth."
- President John F. Kennedy, 25th May, 1961, United States Congress, Washington DC
The Soviets had made a late start in the moon race, despite their early successes with Sputnik, Vostok and Voskhod. The various Design Bureaux constituting the Soviet space programme all had their own, mutually competing lunar mission proposals with which to counter President Kennedy’s 1961 declaration. However, the Soviet leadership, under Nikita Khrushchev, were not convinced that a response was either necessary or desirable. The military, under whose responsibility the space programme fell, could see no strategic or tactical advantage from a lunar mission, while the costs would be enormous. Despite some spectacular growth since the end of the Second World War, Soviet Gross National Product remained less than a third of the United States’ GDP, meaning a straight like-for-like investment in a Moon shot was unthinkable. In fact, many Soviet analysts doubted that such a commitment of resources was sustainable on the American side either, predicting that the US would pull back from, or at least slow down, their gargantuan project.
By 1964, it had become apparent that the US were serious about landing on the Moon, and the Soviet leadership turned to the Council of Chief Designers to propose a programme that could beat the Americans to the surface. They were not short of options.
From Vladimir Chelomei’s OKB-52 came the UR-700 project. Using the same storable N2O4/UDMH propellant technology as his already-approved UR-500 rocket, the UR-700 wound gang rocket bodies together to form a monstrous 4-stage launcher capable of putting over 200 tonnes of payload into Earth orbit. This would support a ‘direct ascent’ lunar mission, putting his LK-700 spacecraft with two cosmonauts on a trajectory straight to the lunar surface, with no need for the complicated rendezvous and docking techniques chosen by the Americans. Once their mission was completed, the LK-700 ascent stage would again place the crew on a direct course for Earth, making a direct re-entry using the conical return vehicle’s aerodynamic shape to manoeuvre to a landing zone in the USSR.
In Dnepropetrovsk, Mikhail Yangel’s design bureau were developing their own large rocket design based on the same storable propellants as Chelomei. After initially considering a simple clustering of his successful R-16 rockets, Yangel’s engineers decided in favour of a monoblock design with a basic diameter of 6.5m. This was sized to allow the transportation of rocket stages via the Soviet canal network, and is an example of the sort of practical considerations that had made Yangel’s bureau popular with the military. Called R-56, the ‘super-rocket’ consisted of three stages, with an optional fourth stage for geosynchronous or lunar payload. However, despite the impressive leap in scale over any currently existing launchers, the R-56 was underpowered compared to the offerings of other bureaus, capable of putting just 40 tonnes into low Earth orbit. For lunar missions, Yangel proposed to upgrade the engines and cluster multiple R-56 stages, but this would still necesitate a dual launch strategy, with all the accompanying concerns over the unknowns of docking operations in space.
At OKB-1, Sergie Korolev, the mastermind behind the earliest Soviet space spectaculars, proposed a mission that much more closely followed the template of Apollo. Like Apollo, a single launch would place a Lunar Orbital Ship and a lander on-course to the moon, though with a crew of two rather than Apollo’s three. Once in lunar orbit, a single cosmonaut would transfer to the lander and descend to the surface. At the completion of his surface activities, the cosmonaut would use a smaller ascent stage of the lander to return to his comrade in orbit, after which both would return to Earth via a double-skip re-entry, spreading the thermal load of deceleration for lunar return velocity.
The rocket Korolev proposed to use to launch his lunar mission was the N-1. Originally proposed in 1960 as a 50 tonne class “Carrier” (“Nositel”) vehicle, the N-1 had been approved for production in September 1962 with a target payload capability of 75 tonnes to low Earth orbit. To meet this increased performance target, Korolev had insisted on the use of kerosene and liquid oxygen as propellants, rather than the storable propellants favoured by Chelomei. This choice put Korolev at odds with Valetin Glushko, Chief Designer of OKB-456 and the USSR’s premier manufacturer of rocket engines, who refused to supply kerolox engines for N-1. Korolev had instead turned to Nikolai Kuznetsov’s OKB-276 to develop the 1.5 Mega-Newton thrust closed cycle engines that would be clustered together to lift the rocket at its payload into space.
As to what that payload would be, this remained undecided at the time of N-1’s approval. Korolev proposed several options, including nuclear-armed military space stations, crewed fly-by missions of Mars or Venus, and a menu of lunar orbital and surface missions using multiple launches and Earth-orbit assembly techniques. Only with the 1964 call to beat Apollo to the Moon did N-1 gain a concrete mission.
If Korolev was going to beat the Americans - and Chelomei - to the prize, it would mean taking the most direct path: a single launch mission, removing all unnecessary complications, to deliver results in the shortest time with the lowest risk. This logic is what led Korolev to propose the N1-L3 mission, and what convinced the Soviet leadership to entrust him - not Chelomei - with the responsibility guiding the USSR to victory in the Moon race. On 3 August 1964 Command number 655-268 issued by the Central Committee of Communist Party of the Soviet Union commanded OKB-1 to put a man on the moon.
There was only one problem: The N1-L3 mission demanded a starting payload in low Earth orbit of at least 95 tonnes.
N-1 had a payload capability of 75 tonnes.
To bridge this critical gap, Korolev and his team planned some significant changes to the N-1's design. First, the number of NK-15 engines on the ‘Blok-A’ first stage would be increased from an already impressive 24 to a total of 30, and the thrust of each of those engines was to be increased by 2%. To fit more propellant into the tanks, the kerosene and liquid oxygen would be super-cooled before fueling, increasing its density, while a change in the design of the pressurisation system and the removal of some telemetry equipment would reduce the launcher’s dry mass. Finally, the parking orbit used for the mission was changed from 300km at 65 degrees inclination, to a lower 200km, 51.8 degree orbit.
Work on the N-1 continued at an increasing pace throughout the rest of 1964 and into 1965, largely unaffected by the replacement of Khrushchev by Brezhnev at the top of the Soviet government. By December 1964 the advanced design project for the N1-L3 mission had been completed, and construction of the twin pads at Baikonur’s Site-110 was advancing. The following January saw orders issued for a total of sixteen N1-L3 stacks to be produced, and throughout 1965 plans were laid for further evolutions of the N-1 that would improve performance and reliability through better engines and high energy upper stages.
In contrast to this image of industrious progress at OKB-1, Chelomei had several of his projects cancelled by a new regime that saw him as having been just a bit too cosy with the ousted Khrushchev. This culminated in August 1965 with the humiliation of having the spacecraft for the planned L1 circumlunar mission changed from Chelomie’s LK-1 to a Soyuz derived spacecraft manufactured by Korolev - though still to be launched on Chelomie’s Proton rocket.
By the end of 1965, it seemed that Korolev was on the verge of his dream of assuming total control of the USSR’s space programme, but behind the scenes things were not going quite as smoothly as he was presenting. Efforts to increase the performance of the NK-15 engines were facing problems, and with no money available for a ground test facility for the complete first stage, there were concerns over the effects of lighting 30 engines together for a launch. The various weight-saving and performance-boosting measures for the launcher were struggling to meet their goals, while the mass of the L3 complex to be sent to the Moon (the LOK moon ship, LK lander, and their Blok-D and Blok-G rocket stages) remained stubbornly outside the envelop of what N-1 could deliver.
To further reduce the demands on the rocket, increasingly risky strategies were incorporated into the mission plan. In one such change, it was decided that the LOK and LK would dock using a simple punch-and-grab mechanism, with no heavy internal hatch, requiring a cosmonaut to perform two spacewalks in lunar orbit to transfer between ships. Another change saw fuel reserves for the LK lander cut to a bare minimum, then cut again, relying on a pre-placed Lunikhod probe to scout the area and deploy a radio guidance beacon, avoiding the need for the lander to hover whilst its pilot hunted for a safe landing zone. These and similar changes led to some disquiet within the cosmonaut corps, and inside of OKB-1 itself, but Korolev remained upbeat and active despite his crushing workload, and his motivation abilities, political skill, and record of success convinced those working for him that they would somehow overcome the obstacles before them and succeed in their mission.
Then, on 14th January 1966, while undergoing surgery to remove a cancerous growth from his colon, Sergie Pavolvich Korolev died.
The sudden and unexpected passing of the Chief Designer left a vacuum of leadership at the top of OKB-1 (now called TskBEM, standing for the Central Design Bureau of Experimental Machine Building). The general assumption was that Vasily Mishin, Korolev’s former deputy, would take over, but political in-fighting within the Central Committee meant that his appointment was not confirmed until May 1966, four months after Korolev’s death.
Despite this delay, work on the lunar project continued. By February 1967 the twin LC-110 launch pads were approaching completion, and a full-sized mock-up of the N-1 rocket, called 1M1, had started construction. March 1967 saw the first uncrewed test flight of the Soyuz 7K-L1 circumlunar ship and its Blok-D upper stage on a Proton rocket. Designated Kosmos 146, the test successfully placed the ship into an elliptical Earth orbit, carefully directed away from the Moon to disguise its purpose. Plans were laid for the first crewed L1 circumlunar flight to take place by the end of 1967, to be followed by an aggressive schedule of N-1 test flights to start in March 1968 and leading to a manned lunar landing by the end of that year. The loss of the follow-up Kosmos 154, which saw the Blok-D stage fail to start in orbit, was disappointing, but overall it appeared that the Soviet lunar programme had weathered the storm of Korolev’s loss remarkably well.
By the end of 1968, no such optimism was possible. A series of failures of the Proton launcher and the 7K-L1 spacecraft (now called “Zond”) dashed hopes of beating the US in a flight around the Moon, with Apollo 8 claiming that prize in December 1968. The L3 landing project was faring no better, with the first flight model, N1-4L, developing cracks in the Blok-A oxygen tank that led to it being rolled back into the assembly building for refit. The next model, N1-3L, underwent fitting and engine tests on the pad in the summer of 1968, but when it returned to the pad for the first N-1 launch attempt on 21st February 1969, an engine fire and failure of the KORD control system led to the total loss of the rocket. A second attempt was made with vehicle N1-5L on 3rd July 1969, but this resulted in an even greater disaster, with another KORD failure shutting off the engines just seconds into the flight. The fully fueled rocket crashed back into its launch pad, destroying the pad in an explosion so large that it was visible to US weather satellites. Two weeks later, Neil Armstrong and Buzz Aldrin stepped out onto the Sea of Tranquillity.
The Moon Race was over.