The Soviet Manned Lunar Program: A Story of Failure
The responsibility for the development of the manned lunar program rested mainly on the shoulders of Korolev, considered the father of Soviet astronautics. At the beginning of his career, Korolev worked on the development of auxiliary rocket engines for aircrafts at the famous manufacturer Tupolev. In 1938, victim of the Stalinist purges, he was sent to a gulag. Thanks to Tupolev's intervention, he was quickly transferred to a charachka, a work camp for engineers, where he continued his work on rockets. In 1945, Korolev was sent to Germany to collect as much information as possible on V2 missiles.
After Stalin's death in 1953, he was placed at the head of the NII-88 design office, where he developed rockets derived from the V2. He then became director of the special OKB-1 design office where he took Mishin as his assistant. Korolev is developing long-range missiles, the last of which, the R-7, will put Sputnik and Gagarin into orbit. This rocket is still used today to launch the Soyuz. He is also undertaking the study of a super launcher, the N-1, a rocket designed to send cosmonauts into space for a flight over Mars and Venus. Yet, the funds necessary to carry out this project are not allocated to him but to his direct competitor Chelomey, head of the OKB-52 design office, who receives funding to develop a less powerful launcher, the UR-500, alias Proton.
It was only in 1964, two years after Kennedy launched the American lunar program, that the USSR became aware of the delay in its own program. The N-1 project was resumed a year later, but Korolev, assisted by Mishin, had to fight to obtain the funding and human resources necessary to adapt the N-1. Indeed, the original N-1 does not allow to put more than 72 t in low orbit, a payload insufficient to send a man to the Moon. In order to improve the power of his rocket, Korolev turned to Glushko, who had a monopoly on the manufacture of rocket engines. The latter offered him hypergolic engines but, finding this technology too dangerous, Korolev refused them. It was Chelomey who, having received the green light for a circumlunar mission inhabited with his UR-500, associated himself with Glushko. This prestigious operation to mark the 50th anniversary of the October Revolution was finally not carried out due to delays in the development of the project. Chelomey was also planning to send a man to the Moon, but with a different strategy, a direct flight. To this end, he projected a gigantic rocket, the UR-700. Like its American counterpart, the Nova launcher, the UR-700 project will not be launched.
It is the aircraft engine manufacturer Kuznetsov, from the engineering firm OKB-276, who will develop the N-1 engines for Korolev. Despite his lack of experience in this field, Kuznetsov will develop a revolutionary closed-cycle engine, the NK-15, producing 25% more thrust than conventional open-cycle engines. Thanks to these engines, the N-1 increased its payload by 23t, allowing to land a man on the Moon. But these engines are small in size. The USSR did not have the technology to produce large engines like those of the American Saturn V rocket. That's why the N-1 has 30 engines for its first stage.
Unfortunately, Korolev died during surgery in early 1966. It is at the time of its national funeral that the Western world learned of his existence. Indeed, Korolev was so important to the space program that the Soviets had hidden his existence fearing that the Americans would murder him. Mishin is the only one who dared to take over the reins of the program but he did not have the charisma of his predecessor nor his contacts in the Kremlin. The program is running late but sixteen N-1 launchers are still ordered, including twelve planned for tests, following Korolev's philosophy of first testing and then correcting. Finally, only eight N-1s will be built.
The guidance of the rocket is carried out by differential thrust of the engines managed by a computer called KORD. On the first flight, on 21 February 1968, the KORD system shut down the engines after a kerosene leak and the N-1 3L rocket crashed to the ground after 70 seconds of flight. On the second flight, on July 3rd of the same year, the explosion of a turbopump caused the engines to shut down by the same system. The N-1 5L rocket crashed on its launch pad, destroying it completely. An engineer's model, the N-1 1ML, on the 2nd launch pad remains miraculously intact. The 3rd test was carried out on June 26, 1971, this time it was an uncontrollable roll that caused the rocket to explode. On November 23, 1972, during the last test, the rocket exploded after 107 seconds of flight following the destruction of an oxygen pump by pogo effect.
A 5th flight was planned for 1974 with a new version and an increased payload: the N-1F. But Mishin was replaced by Glouchko, who quickly ended the lunar program to finance other space projects. The remaining N-1s were destroyed: the failure of the manned lunar program had to be kept secret from the world at all costs. Kutznetov managed to avoid to preserve from destruction 60 improved engines, NK-33, planned for the new N-1F. They were sold twenty years later to Aerojet, an American company that renamed them AJ 26-58 and AJ 26-29.