In the early stage of the Soviet and US crewed lunar programs, U.S. President
John F. Kennedy proposed before the
United Nations a joint Moon program, a proposal which was considered by
Nikita Khrushchev. The proposal disappeared with Kennedy's assassination two months later, but nevertheless foreshadowed the
Apollo-Soyuz mission, which enabled subsequently the
Shuttle-Mir program and the
ISS. The Soviet government issued a response to the American Apollo challenge after three years. According to the first government decree about the Soviet crewed Moon programs (Decree 655-268, '
On Work on the Exploration of the Moon and Mastery of Space '), adopted in August 1964, Chelomei was instructed to develop a Moon flyby program with a projected first flight by the end of 1966, and Korolev was instructed to develop the Moon landing program with a first flight by the end of 1967. Following the change in Soviet leadership from Khrushchev to
Leonid Brezhnev in 1964, the Soviet government in September 1965 assigned the flyby program to Korolev, who redesigned the cislunar mission to use his own
Soyuz 7K-L1 spacecraft and Chelomei's Proton rocket. Korolev organized full-scale development of both programs, but died after surgery in January 1966. According to a government decree of February 1967, the first crewed flyby was scheduled for mid-1967, and the first crewed landing for the end of 1968.
Moon flyby UR-500K(Proton)/L1(Zond) program circumlunar spacecraft Launched by a 3-staged Proton rocket, the L1 (Zond) was a spacecraft from the
Soyuz family and consisted of two or three modified modules of the main craft
Soyuz 7K-OK with a total weight of 5.5 tons. The Apollo orbital spacecraft (command ship) for the lunar flyby also had two modules (command and service) but was five times heavier, carried a crew of three and entered lunar orbit, whereas the L1 (Zond) performed a flight around the Moon and came back on a return trajectory. In September 1968
Zond 5 carried the first Earth lifeforms, including two tortoises, to travel around the Moon and return safely. Planned for 8 December 1968 for priority over the US, a first crewed mission of the L1 (Zond) was canceled due to the insufficient readiness of the capsule and rocket. After
Apollo 8 won the first (lunar orbit) phase of the Moon Race at the end of 1968, the Soviet leadership lost political interest in the L1 (Zond) program. A few reserve units of L1 (Zond) made unpiloted flights, but by the end of 1970, this program was canceled.
Moon landing N1/L3 program The crewed landing plan adopted a similar method to the single launch and
lunar orbit rendezvous of the Apollo project. For mission safety, weeks before the crewed mission, an LK-R uncrewed L3 complex and two
Lunokhod automated rovers would be sent to the Moon, to work as radio beacons for crewed LK, with the LK-R used as a reserve escape craft. The Lunokhods were also equipped with manual controls for the cosmonauts, both for transfer to LK-R in necessity and for regular research. The N1 rocket would then carry the L3 Moon expedition complex, with two spacecraft (LOK and LK) and two (
Block G and
Block D) boosters. A variant of the Soyuz craft, the
"Lunniy Orbitalny Korabl" (LOK) command module, would carry two men, with three modules like the regular
Soyuz 7K-OK, but was heavier by a few tons. The 7K-OK was half the mass of the three-crew Apollo orbital command ship. The
"Lunniy Korabl" (LK) accommodated only one cosmonaut, so in the Soviet plan, only one cosmonaut would land on the Moon. The mass of the LK was 40% of the mass of the Apollo lunar lander. The L3 complex to be placed in
LEO by the N1 was 93 tons (compared to
Saturn V's 137 tons). The mass of the LOK and LK was 40% of the Apollo complex, but was equivalent to the L3 complex without Block G. The booster for the LEO toward the Moon for the Apollo vehicle was provided by the last stage of the Saturn V, while for the Block D, LOK and LK, this was to be provided by
Block G of the same L3 complex. During the L3 complex's journey to the Moon, the cosmonaut would transfer between the LOK and LK by a 'spacewalk'. On the Apollo missions, the transfer was done using an internal passage called the docking tunnel.
Block D was to slow the LOK and LK into lunar orbit, while with Apollo this phase was undertaken by firing the engine on the service module to slow the complex and enter lunar orbit since the Apollo complex traveled with the Command Module and Lunar Excursion Module (LEM) facing back towards the Earth. Once in orbit, the LK with Block D would separate from the LOK and descend toward the surface of the Moon using the Block D engine. After Block D exhausted its fuel, the LK was to separate and complete landing using its own
Blok E engine. On the Moon, the cosmonaut would take Moon walks, use Lunokhods, collect rocks, and plant the
Soviet flag. After a few hours on the lunar surface, the LK's engine would fire again using its landing structure as a launch pad, as with Apollo. To save weight, the engine used for landing would blast the LK back to lunar orbit for an automated docking with the LOK. The cosmonaut then would spacewalk back to the LOK carrying rock samples. The LK would then be cast off, after which the LOK would fire its rocket for the return to Earth.
Launch schedules As of 1967, the L1/L3 launch schedules were:
UR-500K(Proton)/L1(Zond) program :2P: Develop Block D stage (February or March 1967) :3P: Develop Block D stage (March 1967) :4L: Uncrewed lunar flyby (May 1967) :5L: Uncrewed lunar flyby (June 1967) :6L: Crewed lunar flyby (June or July 1967) :7L: Crewed lunar flybys (August 1967) :8L: Crewed lunar flybys (August 1967) :9L: Crewed lunar flybys (September 1967) :10L: Crewed lunar flybys (September 1967) :11L: Crewed lunar flybys (October 1967) :12L: Crewed lunar flybys (October 1967) :13L: Reserve spacecraft
N1/L3 program :3L: Develop LV & Blocks G&D (September 1967) :4L: Reserve :5L: LOK/LK uncrewed (December 1967) :6L: LOK/LK uncrewed (February 1968) :7L: Crewed LOK/uncrewed LK (April 1968) :8L: Crewed LOK/uncrewed LK (June 1968) :9L: Crewed LOK/uncrewed LK with LK lunar landing (August 1968) :10L: First crewed lunar landing (September 1968) :11L: Reserve :12L: Reserve Korolev's death in 1966, along with various technical and administrative reasons, as well as a lack of financial support, resulted in both programs being delayed.
Cosmonauts In 1966, two cosmonaut training groups were formed. One group was commanded by
Vladimir Komarov and included
Yuri Gagarin, and was to prepare for qualification flights of the Soyuz in Earth orbit and a Proton-launched cis-lunar mission (Gagarin,
Nikolayev,
Komarov,
Bykovsky,
Khrunov; Engineer-Cosmonauts:
Gorbatko,
Grechko,
Sevastyanov,
Kubasov,
Volkov). Komarov later died in the
Soyuz 1 spaceflight when his parachute malfunctioned causing his capsule to smash into the earth at high speed. The second group was led by
Alexei Leonov and concentrated on the landing mission (Commanders: Leonov,
Popovich,
Belyayev,
Volynov,
Klimuk; Engineer-cosmonauts: Makarov, Voronov, Rukavishnikov, Artyukhin). As a result, Leonov has the strongest claim to have been the Soviets' first choice for the first man on the Moon. After Komarov's death in
Soyuz 1 in 1967, Gagarin was taken out of training and the groups were restructured. Despite the Soyuz 1 setback, the Soviets successfully rehearsed the automated docking of two uncrewed Soyuz craft in Earth orbit in 1968 and with the crewed
Soyuz 4 and
Soyuz 5 joint mission in early 1969 tested the other key mission elements. A total of 18 missions were related to the N1-L3 project. ==Later developments==