Soyuz 7K-T No.39 (Soyuz 18a / Soyuz 18-1)

Soyuz 7K-T No.39 (Soyuz 18a), crewed by Lazarev and Makarov toward Salyut 4; aborted when core stages failed to separate, forcing a high-g ballistic recovery from a suborbital trajectory.

Outcome

Failure

Orbit

LEO

Low Earth orbit

Payload to orbit

Did not reach orbit

Flight

29th

of 32 Soyuz 11A511 flights

Date and time

5 April 1975, 11:04 UTC

Rocket

Soyuz 11A511

Builder

Progress RSC

Launch site

1/5, Baikonur Cosmodrome, Republic of Kazakhstan

Payload

Human Exploration

Launches in 1975

26th of 132