Soyuz 7K-L1

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Soyuz 7K-L1
Zond L1 drawing-color.png
Manufacturer OKB-1
Country of origin Soviet Union
ApplicationsCarry cosmonauts around the Moon and back to Earth
Production
StatusCancelled programme
Built15
Launched12
Retired3
Related spacecraft
Derived from Soyuz 7K-OK [1]
Derivatives Soyuz 7K-LOK [ citation needed ]
An artist's impression of the Soyuz 7K-L1 en route to the Moon. ZOND.jpg
An artist's impression of the Soyuz 7K-L1 en route to the Moon.

Soyuz 7K-L1 "Zond" spacecraft was designed to launch cosmonauts from the Earth to circle the Moon without going into lunar orbit in the context of the Soviet crewed Moon-flyby program in the Moon race. It was based on the Soyuz 7K-OK. [2] Several modifications reduced vehicle mass and increased circumlunar capability. The most notable modifications were the replacement of the orbital module with a support cone and a high-gain parabolic antenna, the removal of a reserve parachute, and the addition of the gyro platform and star navigation sensors for the far space navigation. The spacecraft was capable of carrying two cosmonauts. At the start of flight testing, there were serious reliability problems with the new Proton rocket, the 7K-L1, and the Soyuz 7K-OK that the L1 was based on.

Contents

History

Chief Designer Sergei Korolev had originally envisioned a crewed lunar spacecraft launched in pieces by R-7 boosters and assembled in Earth orbit. The development of Vladimir Chelomei's large UR-500 booster theoretically made it possible to do the job in a single launch. However, Chelomei also proposed his own, competing for lunar spacecraft, the LK-1, and Soviet premier Nikita Khrushchev gave his approval in August 1964. Two months later, Khrushchev was expelled from power and Chelomei lost his principal patron. At the end of the year, Korolev revived his proposal for the Soyuz spacecraft but concealed his true intentions by billing it as an Earth orbital vehicle for testing rendezvous and docking maneuvers. In October 1965, a mere three months before his death, Korolev was granted official approval for developing a crewed lunar spacecraft, which would be a modified Soyuz. This would be launched towards the Moon on a UR-500 topped with the Blok D stage under development by the OKB-1 Bureau.

Korolev originally intended to piece together the lunar Soyuz in Earth orbit because he did not believe the UR-500 was powerful enough to launch the full vehicle or that it wouldn't be safe for the crew. However, when he died in January 1966, his successor as head of OKB-1, Vasily Mishin, argued that it was definitely possible to strip down the Soyuz enough to launch it with the UR-500.

With the first four uncrewed test starts (see below) being partially successful or unsuccessful, including two under the common open name "Kosmos" as for any Soviet test spacecraft, the mission of 2–7 March 1968 and subsequent ones were the flights of the L1 spacecraft under the open designation "Zond" that were given by Soviets for test missions to far space.

After the successful United States Apollo 8 crewed flight around the Moon, the Soviet crewed Moon-flyby missions lost political motivation. The first crewed flight of the L1/Zond spacecraft with Alexei Leonov and Valery Bykovsky planned for the end of 1970 was cancelled. In addition, the Proton booster was far from being human-rated and its poor launch record made it undesirable for crewed flights.

All L1/Zond spacecraft made only uncrewed flights from 1967 to 1970, from (Zond 4 to Zond 8), and four of these five Zond flights suffered malfunctions. Test flights conducted around the Moon showed problems using their star sensors for navigation. These problems caused ballistic reentry due to failed guidance. One direct descent re-entry was performed on a steep ballistic trajectory with a deceleration of up to 20 Gs and splashed down in the Indian Ocean. Three others performed a maneuver known as "skip reentry" to shed velocity. One of those also performed an unsafe (for humans) descent of up to 20 Gs of deceleration, the other suffered main parachute failure, and only one flight - Zond 7 - would have been safe for cosmonauts.

Instrumentation flown on these missions gathered data on micrometeor flux, solar and cosmic rays, magnetic fields, radio emissions, and solar wind. Many photographs were taken and biological payloads were also flown. Zond 5 was the first spacecraft to carry a group of terrestrial creatures (tortoises being the most complex) on a circumlunar flight and return them relatively safely to Earth. Zond 5 splashed down in the Indian Ocean after descending steeply with a 20 G deceleration rate. Although unsafe for humans, these high Gs apparently didn't affect the tortoises' health, and they were reportedly able to breed afterward. [3]

Two modifications of main Soyuz 7K-L1 "Zond" version was created: the powered (up to 7000 kg mass) Soyuz 7K-L1S "Zond-M" that were failed attempted to launch for Moon flyby on N1 rocket two times due to Soyuz 7K-LOK orbital ship-module of L3 lunar expedition complex was not ready; the Soyuz 7K-L1E "Zond-LOK" as dummy mockup of Soyuz 7K-LOK and were successfully launched on Low Earth Orbit on Proton rocket as Kosmos 382 and failed launched for Moon orbiting on third N1 rocket.

No official name for crewed Soyuz 7K-L1 "Zond" was adopted. According to Mishin's and Kamanin's memoirs, the names "Rodina" (motherland), "Ural" ( Ural mountains), "Akademik Korolyov" (academician Korolyov ). Also, "Zarya" (dawn) and "Znamya" (banner) were proposed for both lunar Soyuz 7K-L1 flyby and Soyuz 7K-LOK orbital ships. The information display systems (IDS) on the L1 was called "Saturn" and featured some differences from the standard 7K-OK "Sirius-7K" IDS.

Along with the remaining 7K-L1S, the Soviet Moon-flyby program was closed in 1970 without the achievement of its crewed primary goal. The intended crewed use of L1/Zond spacecraft was documented in official Soviet sources for the first time but from 1968 until 1989 this and the Moon-landing N1-L3 programs were classified and the Soviet government denied the existence of both. Near 1968 a rare open Soviet source (Big Soviet Encyclopedia's Yearbook, Kosmonavtika small encyclopedia) sporadically referred to Zonds as tests of space ships for lunar missions in contrast to the space apparate term used by the Soviets for spacecraft not capable of carrying a crew.

Planned schedule

Proton 7K-L1 launch vehicle configuration Proton-L1 (Zond) drawing.png
Proton 7K-L1 launch vehicle configuration

As of 1967, the Soyuz 7K-L1 launch schedule was:

Mission

In July 1968, it was proposed that L1 spacecraft would be launched every month, and the first crewed mission would be in December 1968 or January 1969 after 3 or 4 successful uncrewed flights. In December 1968, dates for three crewed L1 missions were set to March, May, and July 1969. Finally, in September 1969 one crewed L1 mission was formally set for April 1970.

Built spacecraft

Fifteen Soyuz 7K-L1 were built:

Test missions

Related Research Articles

<span class="mw-page-title-main">Soyuz programme</span> Human spaceflight programme of the Soviet Union

The Soyuz programme is a human spaceflight programme initiated by the Soviet Union in the early 1960s. The Soyuz spacecraft was originally part of a Moon landing project intended to put a Soviet cosmonaut on the Moon. It was the third Soviet human spaceflight programme after the Vostok (1961–1963) and Voskhod (1964–1965) programmes.

<span class="mw-page-title-main">Soyuz (spacecraft)</span> Series of spacecraft designed for the Soviet space programme

Soyuz is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau. The Soyuz succeeded the Voskhod spacecraft and was originally built as part of the Soviet crewed lunar programs. It is launched on a Soyuz rocket from the Baikonur Cosmodrome in Kazakhstan. Between the 2011 retirement of the Space Shuttle and the 2020 demo flight of SpaceX Crew Dragon, the Soyuz served as the only means to ferry crew to or from the International Space Station, for which it remains heavily used. Although China did launch crewed Shenzhou flights during this time, none of them docked with the ISS.

Zond was the name given to two distinct series of Soviet robotic spacecraft launched between 1964 and 1970. The first series, based on the 3MV planetary probe, was intended to gather information about nearby planets.

<span class="mw-page-title-main">Zond 5</span> 1968 Soviet spaceflight to circle the Moon, first lunar mission to carry animals

Zond 5 was a spacecraft of the Soviet Zond program. In September 1968 it became the first spaceship to travel to and circle the Moon in a circumlunar trajectory, the first Moon mission to include animals, and the first to return safely to Earth. Zond 5 carried the first terrestrial organisms to the vicinity of the Moon, including two tortoises, fruit fly eggs, and plants. The Russian tortoises underwent biological changes during the flight, but it was concluded that the changes were primarily due to starvation and that they were little affected by space travel.

<span class="mw-page-title-main">Zond 6</span> Unsuccessful 1968 Soviet test spaceflight to the Moon

Zond 6 was a formal member of the Soviet Zond program, and an unpiloted version of the Soyuz 7K-L1 crewed Moon-flyby spacecraft. It was launched on a lunar flyby mission on November 10, 1968, from a parent satellite (68-101B) in Earth parking orbit. The spacecraft carried a biological payload of turtles, flies, and bacteria. It also carried scientific probes including cosmic ray, micrometeoroid detectors, and photographic equipment.

<span class="mw-page-title-main">Zond 7</span> 1969 Soviet test spaceflight to the Moon

The Zond 7 spacecraft, part of the Soviet Zond program, was launched towards the Moon on a Proton-K D rocket on August 7, 1969. Its mission was to support studies of the Moon and circumlunar space, to obtain color photography of Earth and the Moon from varying distances, and to flight test the spacecraft systems. It was an unpiloted version of the Soyuz 7K-L1, a crewed Moon-flyby spacecraft.

<span class="mw-page-title-main">Zond 8</span> 1970 Soviet test spaceflight to the Moon

Zond 8, also known as L-1 No.14, was the last in the series of circumlunar spacecraft, a member of the Soviet Zond program, designed to rehearse a piloted circumlunar flight, an uncrewed version of Soyuz 7K-L1 crewed circumlunar flight spacecraft. The project was initiated in 1965 to compete with the Americans in the race to the Moon but lost its importance once three astronauts orbited the Moon on the Apollo 8 mission in December 1968.

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<span class="mw-page-title-main">Zond 4</span> 1968 Soviet test spaceflight

Zond 4, part of the Soviet Zond program and an uncrewed version of Soyuz 7K-L1 crewed Moon-flyby spacecraft, was one of the first Soviet experiments towards crewed circumlunar spaceflight. It was launched to test the spaceworthiness of the new capsule and to gather data about flights in circumterrestrial space. It was the first Soviet spacecraft to possess a computer, the 34 kg Argon 11.

The Soviet crewed lunar programs were a series of programs pursued by the Soviet Union to land humans on the Moon, in competition with the United States Apollo program. The Soviet government publicly denied participating in such a competition, but secretly pursued two programs in the 1960s: crewed lunar flyby missions using Soyuz 7K-L1 (Zond) spacecraft launched with the Proton-K rocket, and a crewed lunar landing using Soyuz 7K-LOK and LK spacecraft launched with the N1 rocket. Following the dual American successes of the first crewed lunar orbit on 24–25 December 1968 and the first Moon landing on July 20, 1969, and a series of catastrophic N1 failures, both Soviet programs were eventually brought to an end. The Proton-based Zond program was canceled in 1970, and the N1-L3 program was de facto terminated in 1974 and officially canceled in 1976. Details of both Soviet programs were kept secret until 1990 when the government allowed them to be published under the policy of glasnost.

<span class="mw-page-title-main">Soyuz 7K-LOK</span> Concept for a lunar spacecraft derived from Soyuz

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<span class="mw-page-title-main">Soyuz 7K-L1 No.5L</span> Failed 1967 Soviet test spaceflight

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<span class="mw-page-title-main">Soyuz 7K-L1 No.4L</span> Failed 1967 Soviet test spaceflight

Soyuz 7K-L1 No.4L, sometimes identified by NASA as Zond 1967A, was a Soviet spacecraft which was launched in 1967 as part of the Zond programme. It was a 5,390-kilogram (11,880 lb) Soyuz 7K-L1 spacecraft, the first of nine to be launched. Although it was intended to perform a circumlunar flyby of the Moon before returning to the Earth for landing, it failed to achieve Earth orbit.

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Kosmos 146, also known as L-1 No. 2P, was a Soviet test spacecraft precursor to the Zond series, launched from the Baikonur Cosmodrome aboard a Proton K rocket.

<span class="mw-page-title-main">Kosmos 154</span> Failed Soviet orbital test flight (Zond)

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<span class="mw-page-title-main">Soyuz 7K-L1E</span>

Soyuz 7K-L1E was a Soviet uncrewed modified Soyuz 7K-L1 spacecraft. Also called a dummy Soyuz 7K-LOK. Two were built, one Soyuz 7K-L1E was successfully launched into Low Earth Orbit on Proton rocket and is known as Kosmos 382. The other Soyuz 7K-L1E was placed on a N1 rocket, which failed at launch. The Soyuz spacecraft was first used in 1967 as the main crewed spacecraft and is still in use. Many Soyuz variations have been built and the Soyuz 7K-L1E was an uncrewed variation.

<span class="mw-page-title-main">Sever (spacecraft)</span> Planned crewed spacecraft of the early Soyuz programme

Soyuz Sever, also spelled Soyuz Siber,, was an early (1959–1962) design of the Soyuz spacecraft. The Soyuz Sever design of a crewed spacecraft started the Soyuz programme. In 1956, the Soyuz Sever spacecraft was proposed as the replacement for the Vostok spacecraft. Vostok spacecraft had only a crew of one; the Soyuz Sever plan would have crew of three. Sever was planned to be launched on a R7 rocket or Vostok rocket. The Sever plans were made by the Experimental Design Bureau (OKB-1) of the Soviet Union. While the Sever spacecraft was never built and launched, many of the designs and testing outcomes became part of the first generation Soyuz spacecraft, Soyuz 7K-OK and the Soyuz 1 mission launched on 23 April 1967. Sever final plan was to take crews to a Sever space station, OS-1962.

References

  1. Siddiqi, Asif (March 2003). Simpson, Clive; Owens, Lucy (eds.). "Soyuz variants: a 40-year history" (PDF). British Interplanetary Society. 45 (3): 119.
  2. "Soyuz 7K-L1". astronautix.com. Archived from the original on 20 August 2016. Retrieved 12 October 2018.
  3. http://www.novosti-kosmonavtiki.ru/content/numbers/252/43.shtml (in Russian)