Names | Soyuz 7K-L1 s/n 12 | ||||||||
---|---|---|---|---|---|---|---|---|---|
Mission type | Planetary Science | ||||||||
Operator | Lavochkin | ||||||||
COSPAR ID | 1968-101A | ||||||||
SATCAT no. | 03535 | ||||||||
Mission duration | 7 days | ||||||||
Spacecraft properties | |||||||||
Manufacturer | NPO Energia Company [ citation needed ] | ||||||||
Launch mass | 5,375 kg (11,850 lb) [1] | ||||||||
Start of mission | |||||||||
Launch date | 19:11:31,10 November 1968(UTC) [1] | ||||||||
Rocket | Proton-K/11S824 | ||||||||
Launch site | Baikonur 81/26 | ||||||||
End of mission | |||||||||
Disposal | Crash landed | ||||||||
Landing date | 17 November 1968 14:10 UT [1] | ||||||||
Landing site | 70 km NE of Tyuratam, Kazakhstan, USSR [2] | ||||||||
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 approach | 14 November 1968 | ||||||||
Distance | 2,420 km (1,500 mi) | ||||||||
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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. [3]
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 when the parachute was detached from the capsule too early.
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 mmHg (3.3 kPa) capsule pressure. If the capsule had been completely depressurised to a high vacuum, the accident would not have occurred.
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.
The Space Race was a 20th-century competition between two Cold War rivals, the United States and the Soviet Union, to achieve superior spaceflight capability. It had its origins in the ballistic missile-based nuclear arms race between the two nations following World War II and had its peak with the more particular Moon Race to land on the Moon between the US moonshot and Soviet moonshot programs. The technological advantage demonstrated by spaceflight achievement was seen as necessary for national security and became part of the symbolism and ideology of the time. The Space Race brought pioneering launches of artificial satellites, robotic space probes to the Moon, Venus, and Mars, and human spaceflight in low Earth orbit and ultimately to the Moon.
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.
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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.
A Moon landing or lunar landing is the arrival of a spacecraft on the surface of the Moon, including both crewed and robotic missions. The first human-made object to touch the Moon was Luna 2 in 1959.
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This article was originally based on material from NASA (NSSDC) information on Zond 6