Soyuz 18a
| Mission duration | 21 minutes 27 seconds | ||||
|---|---|---|---|---|---|
| Orbits completed | Failed to orbit | ||||
| Apogee | 192 kilometres (119 mi) | ||||
| Spacecraft properties | |||||
| Spacecraft type | Soyuz 7K-T | ||||
| Manufacturer | OKB-1 | ||||
| Launch mass | 6,830 kilograms (15,060 lb) | ||||
| Crew | |||||
| Crew size | 2 | ||||
| Members |
Vasili Lazarev Oleg Makarov |
||||
| Callsign | Урал (Ural - "Ural") | ||||
| Start of mission | |||||
| Launch date | April 5, 1975, 11:04:54 UTC | ||||
| Rocket | Soyuz | ||||
| Launch site | Baikonur 1/5 | ||||
| End of mission | |||||
| Landing date | April 5, 1975, 11:26:21 UTC | ||||
| Landing site |
Altay Mountains (official) 50°50′N 83°25′E / 50.833°N 83.417°E |
||||
| Orbital parameters | |||||
| Reference system | Geocentric | ||||
| Regime | Low Earth | ||||
| Epoch | Planned | ||||
|
|||||
Soyuz 7K-T No.39, (also named Soyuz 18a or Soyuz 18-1 by some sources and also known as the April 5 Anomaly) was an unsuccessful launch of a manned Soyuz spacecraft by the Soviet Union in 1975. The mission was expected to dock with the orbiting Salyut 4 space station, but due to a failure of the Soyuz launch vehicle the crew failed to achieve orbit. The crew consisted of commander Vasili Lazarev, and flight engineer Oleg Makarov, a civilian. The crew, who feared initially they had landed in China, were successfully recovered.
The accident was 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. While 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).
Soyuz 7K-T No.39 was intended to be the second mission to take cosmonauts to the Soviet Salyut 4 space station for a 60-day mission. Both cosmonauts were on their second mission and had flown their first mission together, Soyuz 12, in September 1973 to test a new type of Soyuz spacecraft after the fatal accident of Soyuz 11.
The launch proceeded according to plan until T+288.6 seconds at an altitude of 145 kilometres (90 mi), 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.
...
Wikipedia