Zond 6

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Zond 6
Zond L1 drawing.svg
NamesSoyuz 7K-L1 s/n 12
Mission type Planetary Science
Operator Lavochkin
COSPAR ID 1968-101A OOjs UI icon edit-ltr-progressive.svg
SATCAT no. 03535
Mission duration7 days
Spacecraft properties
ManufacturerNPO Energia Company [ citation needed ]
Launch mass5,375 kg (11,850 lb) [1]
Start of mission
Launch date19:11:31,10 November 1968(UTC) (1968-11-10T19:11:31Z) [1]
Rocket Proton-K/11S824
Launch site Baikonur 81/26
End of mission
DisposalCrash landed
Landing date17 November 1968 (1968-11-17) 14:10 UT [2]
Landing site70 km NE of Tyuratam, Kazakhstan, USSR [3]
Orbital parameters
Perigee altitude 120 km (75 mi)
Apogee altitude 400,000 km (250,000 mi)
Inclination 51.5°
Period 500 days
Flyby of Moon
Closest approach14 November 1968
Distance2,420 km (1,500 mi)
  Zond 5
Zond 1969A  
 

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, scientific probes including cosmic ray and micrometeoroid detectors, and as photographic equipment.

Contents

The mission was a precursor to a crewed circumlunar flight which the Soviets hoped could occur in December 1968, thus beating the American Apollo 8. However, after rounding the Moon on November 14, Zond 6 crashed on its return to Earth, due to a parachute failure.

Mission

Zond 6 was the official designation for Soyuz 7K-L1 s/n 12. It was supposed to photograph the Moon in colour and in black and white, from 8,000 km and 2,600 km ranges, then return to Earth, landing at Tyuratam, only 16 km from the launch pad. It had been a long and difficult road to develop the L1 guidance system, but it worked perfectly that time.

Zond 6 flew around the Moon on 14 November 1968, at a minimum distance of 2,420 km. Photographs of the lunar near side and far side were obtained with panchromatic film. Each photo was 5 by 7 in (130 by 180 mm). Some of the views allowed for stereo pictures. The photos were taken from distances of approximately 11,000 km and 3,300 km.

The flight was tracked by Jodrell Bank Observatory, which picked up telemetry data and voice transmissions. The telemetry data appear to have been simulated sensor readings; the voices were either from a tape recorder or being relayed through the probe. [4] In 2018, a recording of the signals was found in Jodrell Bank's archive. [4]

During the craft's return from the Moon, concerns arose about the falling temperatures of the hydrogen peroxide tanks. [5] This issue was addressed by rotating Zond 6 so that the tanks were in direct sunlight. [5] While this was successful in raising the temperatures of the tanks, it also damaged the seal around the door of the re-entry cabin, resulting in the spacecraft starting to leak and the pressure in the cabin falling. [5]

Zond 6 used a relatively uncommon technique called "skip reentry" to shed velocity upon returning to Earth. A few hours before reentry, on 17 November 1968, the cabin largely depressurised, killing all the animal test subjects aboard. A further problem resulted in Zond 6's parachutes ejecting while the cabin was still several miles up. The craft crashed in Kazakhstan, near the designated landing area. [6]

Investigation of the remains of the spacecraft was delayed while the self-destruct system was located and removed. [5] The craft's film magazines could then be recovered, and the images therein were published, along with claims that the mission had been entirely successful. [5] [6]

A State Commission investigating the crash later determined that the coronal discharge effect which caused the parachute to jettison would only occur at the 25 mm capsule pressure. If the capsule had been completely depressurised to a high vacuum, the accident would not have occurred.

Details

See also

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<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.

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

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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 3</span> 1965 Soviet moon probe

Zond 3 was a 1965 space probe which performed a flyby of the Moon's far side, taking a number of quality photographs for its time. It was a member of the Soviet Zond program while also being part of the Mars 3MV project. It was unrelated to Zond spacecraft designed for crewed circumlunar missions. It is believed that Zond 3 was initially designed as a companion spacecraft to Zond 2 to be launched to Mars during the 1964 launch window. The opportunity to launch was missed, and the spacecraft was launched on a Mars-crossing trajectory as a spacecraft test, even though Mars was no longer attainable.

<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 7</span> 1969 Soviet test spaceflight to the Moon

Zond 7, a formal member of the Soviet Zond program and unpiloted version of Soyuz 7K-L1 crewed Moon-flyby spacecraft, the first truly successful test of L1, was launched towards the Moon on a Proton-K D rocket on August 7, 1969, on a mission of further 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. Earth photos were obtained on August 9, 1969. On August 11, 1969, the spacecraft flew past the Moon at a distance of 1984.6 km and conducted two picture taking sessions. On its way back from the Moon the spacecraft tested its radio systems by transmitting recorded voices. Zond 7 carried four turtles, a follow-up to the September 1968 Zond 5 mission which carried two tortoises on a circumlunar lunar mission, and the November 1968 Zond 6 mission which also carried turtles.

<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.

<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.

<span class="mw-page-title-main">Space capsule</span> Type of spacecraft

A space capsule is a spacecraft designed to transport cargo, scientific experiments, and/or astronauts to and from space. Capsules are distinguished from other spacecraft by the ability to survive reentry and return a payload to the Earth's surface from orbit, and are distinguished from other types of recoverable spacecraft by their blunt shape, not having wings and often containing little fuel other than what is necessary for a safe return. Capsule-based crewed spacecraft such as Soyuz or Orion are often supported by a service or adapter module, and sometimes augmented with an extra module for extended space operations. Capsules make up the majority of crewed spacecraft designs, although one crewed spaceplane, the Space Shuttle, has flown in orbit.

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. Soviet cosmonauts never orbited nor landed on the Moon. 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">Moon landing</span> Arrival of a spacecraft on the Moons surface

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

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<span class="mw-page-title-main">Soyuz 7K-L1</span>

The 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. 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.

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

Soyuz 7K-L1 No.5L, sometimes identified by NASA as Zond 1967B, 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 second of nine to be launched. It was intended to perform a circumlunar flyby of the Moon before returning to the Earth for landing, but failed to achieve Earth orbit.

<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.

<span class="mw-page-title-main">Circumlunar trajectory</span> Type of free-return trajectory

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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.

Kosmos 154, also known as L-1 No.3P, was a Soviet test spacecraft launched from the Baikonur aboard a Proton-K rocket. It was a prototype Soyuz 7K-L1 launched by Proton. It was an uncrewed precursor to the Zond series.

Zond program was a Soviet robotic spacecraft program launched between 1964 and 1970, using two spacecraft series, one for interplanetary exploration, and the other for lunar exploration.

References

  1. 1 2 Siddiqi, Asif (2018). Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016 (PDF) (second ed.). NASA History Program Office.
  2. Siddiqui, Asif A. "Beyond Earth: A Chronicle of Deep Space Exploration". NASA Science. Retrieved 8 January 2020.
  3. "Zond-6: Racing Apollo-8". www.russianspaceweb.com. Retrieved 29 July 2019.
  4. 1 2 "Jodrell Bank Observatory release 50 year-old audio archive of Soviet Zond 6 lunar mission". manchester.ac.uk/. The University of Manchester. 14 November 2018. Retrieved 30 August 2020.
  5. 1 2 3 4 5 Ulivi, Paolo; Harland, David M (2004). Lunar Exploration Human Pioneers and Robot Surveyors. Springer. pp. 203–204. ISBN   185233746X.
  6. 1 2 Harvey, Brian (2007). Soviet and Russian Lunar Exploration. Springer-Praxis. pp. 188–190. ISBN   978-0387218960.

This article was originally based on material from NASA (NSSDC) information on Zond 6