Soyuz 7K-T No.39
Names | Soyuz 18a, Soyuz 18-1, April 5th Anomaly |
---|---|
Mission type | Docking with Salyut 4 |
Operator | Soviet space program |
Mission duration | 21 minutes 27 seconds 60 days (planned) |
Orbits completed | Failed to orbit |
Apogee | 192.0 km (sub-orbital spaceflight) |
Spacecraft properties | |
Spacecraft | Soyuz 7K-T No.6 |
Spacecraft type | Soyuz 7K-T |
Manufacturer | OKB-1 |
Launch mass | 6830 kg |
Landing mass | 1200 kg |
Crew | |
Crew size | 2 |
Members | Oleg Makarov |
Callsign | Урал (Ural – "Ural") |
Start of mission | |
Launch date | 5 April 1975, 11:04:54 Site 1/5[1] |
End of mission | |
Landing date | 5 April 1975, 11:26:21 UTC |
Landing site | Altai Mountains, Kazakhstan (official) 50°50′N 83°25′E / 50.833°N 83.417°E |
Orbital parameters | |
Reference system | Geocentric orbit (planned) |
Regime | Low Earth orbit |
Altitude | 192.0 km |
Inclination | 51.6° |
Period | 90.0 minutes |
Docking with Salyut 4 (planned) | |
Salyut program insignia |
Soyuz 7K-T No.39, (also named Soyuz 18a or Soyuz 18-1 and also known as the April 5 Anomaly)
The accident was partly disclosed by the normally secretive Soviets as it occurred during preparations for their joint Apollo-Soyuz Test Project with the United States which flew three months later. Lazarev never flew to space again and never fully recovered from the accident; Makarov made two more flights on board a Soyuz (both of which were to the Salyut 6 space station).
Crew
Position | Cosmonaut | |
---|---|---|
Commander | Vasily Lazarev Second and last spaceflight | |
Flight Engineer | Oleg Makarov Second spaceflight |
Backup crew
Position | Cosmonaut | |
---|---|---|
Commander | Pyotr Klimuk | |
Flight Engineer | Vitaly Sevastyanov |
Mission highlights
Soyuz 7K-T No.39 was intended to be the second mission to take
The launch proceeded according to plan until T+288.6 seconds at an altitude of 145 km (90 mi),[5] when the second and third stages of the booster began separation. Only three of the six locks holding the stages together released and the third stage's engine ignited with the second stage still attached below it. The third stage's thrust broke the remaining locks, throwing the second stage free but putting the booster under unexpected strain that caused it to deviate from the proper trajectory. At T+295 seconds, the deviation was detected by the Soyuz's guidance system, which activated an automatic abort program. As the escape tower was long gone by this point, the abort had to be performed with the Soyuz's own engines. This separated the spacecraft from the third-stage booster and then separated the orbital and service modules of the Soyuz from the re-entry capsule. At the time, when the safety system initiated separation the spacecraft was already pointed downward toward Earth, which accelerated its descent significantly. Instead of the expected acceleration in such an emergency situation of 15 g (147 m/s²), the cosmonauts experienced up to 21.3 g (209 m/s²).[2] Despite very high overloading, the capsule's parachutes opened properly and slowed the craft to a successful landing after a flight of only 21 minutes.
The capsule landed southwest of
Initial Soviet reports stated the men had suffered no ill effects from their flight. However, subsequent reports claimed that Lazarev was injured by the high acceleration of re-entry. Makarov went on to take part in Soyuz 26, Soyuz 27, and Soyuz T-3 missions.
In Brezhnev's time, it was rare to disclose anything about Soviet failures, and so the first (Soviet) publication about the realities of the flight was made only a month later (8 May 1975).[6] The Americans were informed on April 7 1975 after the crew had been rescued. However, as the failure occurred during preparations for the joint Apollo-Soyuz Test Project, the United States requested that a more detailed report of the accident be provided. (There was even a United States congressional inquiry regarding this failure and several others.[7]) In the report the Soviets made to the Americans, the abort was referred to as the "April 5th anomaly", and as this was the only term the Soviets ever used for the incident, that became the "official" designation for years afterwards. It was also disclosed that the booster used in the launch was an older model and not the same model that would be used for Soyuz 19.[8] The mission is referred to in some literature as Soyuz 18a or Soyuz 18–1, since the following Soyuz mission in May 1975 received the name Soyuz 18. (The Soviets only gave numbers to successful launches.)
The exact landing site of the capsule was a subject of debate amongst space historians in subsequent years. A Russian source[9] quoted by James Oberg has stated that the landing occurred in Mongolia.[10]
The failed Soyuz mission was the only case of a crewed booster accident at high altitude until the accident with Soyuz MS-10 on 11 October 2018.
Mission parameters
- Mass: 6,830 kg (15,060 lb)
- Apogee: 192.0 km (119.3 mi)
See also
- Soyuz 7K-ST No. 16L, 1983 Soyuz launch failure
- Soyuz MS-10, 2018 in-flight failure
- List of space accidents
References
- ^ Mark Wade. "Baikonur LC1". Encyclopedia Astronautica. Archived from the original on 28 August 2016. Retrieved 11 October 2018.
- ^ ISBN 1-85233-657-9.
- ISBN 0-87201-848-2.
- ISBN 0-517-56954-X.
- ^ ISBN 1-85233-225-5.
- ^ Сидорчик А. «Союз» без номера. В 1975 году советские космонавты выжили, упав из космоса. — «Аргументы и факты», 27 November 2014. (in Russian)
- ^ 1975 Congressional Record, Vol. 121, Page 22528 (July 14, 1975) "Summary of CIA Report on Soviet Readiness to Participate in ASTP" This article incorporates text from this source, which is in the public domain.
- ^ Soviet Space Programs, 1971-75, Volume 1. Committee on Aeronautical and Space Sciences, United States Senate. 1976. p. 211. "April 5th Anomaly" This article incorporates text from this source, which is in the public domain.
- ^ Semyonov, Yuri; et al. (1996). Rocket - Space Corporation 'Energiya' (Fiftieth Anniversary). Moscow.
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: CS1 maint: location missing publisher (link) - ^ Oberg, James (19 March 1997). "Consultant Report: Soyuz Landing Safety". Retrieved 15 December 2007.