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USSR resumes crew missions after deadly accident

In September 1973, the Soyuz-12 spacecraft carried two cosmonauts on a test mission of the new crew vehicle variant modified after the loss of three cosmonauts aboard Soyuz-11 more than two years earlier.

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Soyuz-12 mission at a glance:

Spacecraft designation
Soyuz, 7K-T No. 37, 11F615A8
Launch vehicle
11A511 (Soyuz)
Launch date and time
1973 Sept. 27, 15:18:16 Moscow Time
Launch site
Landing date and time
1973 Sept. 29, 14:33:48 Moscow Time
First autonomous test flight of the piloted modified 7K-T variant
Primary crew
Vasily Lazarev (Commander), Oleg Makarov (Flight engineer)
Backup crew
Aleksei Gubarev (Commander), Georgy Grechko (Flight engineer)
Flight duration
1 day 23 hours 15 minutes 32 seconds

New mission objective

Soyuz vehicle No. 7K-T No. 37, which ultimately flew the Soyuz-12 mission, was originally intended for delivering the second crew to the Salyut DOS-3 space station in 1973.

As of mid-October 1972, Vehicle No. 37 was undergoing final assembly and was scheduled for delivery for integrated testing at the checkout station, KIS, of the TsKBEM design bureau in Podlipki near Moscow on Nov. 30, 1972. At the time, its shipment to the launch site in Tyuratam was planned for March 1973, however, the spacecraft only made it to KIS on Jan. 2, 1973. Its integrated tests were completed in February 1973, revealing a total of 13 faulty components. Nevertheless, the spacecraft was being prepared for shipment to the launch site, however, along with its predecessor, the vehicle was still lacking a parachute system, which was still undergoing upgrades in the wake of the Soyuz-11 accident.

After the loss of the DOS-3 space station in May 1973, Vehicle No. 37 was reconfigured for a short solo flight with two cosmonauts onboard.

Late evening on Aug. 7, 1973, Head of TsKBEM Vasily Mishin had a phone conversation with Dmitry Ustinov, who supervised the rocket and space industry for the Soviet government. Traditionally, Mishin sought the blessing of the Kremlin for the critical decision to return to flight. Next afternoon, Mishin chaired the Chief Designer Council that cleared Vehicle 7K-T No. 37 for flight. Naturally, the officials confirmed two pairs of cosmonauts, who were initially trained to work aboard DOS-3, as primary and backup crews.

Cosmonauts Vasily Lazarev and Oleg Makarov, who spent two years preparing for work on both ill-fated space stations, DOS-2 and DOS-3, had to content with a two-day test flight.

On the morning of August 29, the Military Industrial Commission, VPK, of the Soviet government gave its go to the long-awaited return to flight. (774)

Soyuz-12 lifts off

More than two years after the Soyuz-11 tragedy, on Sept. 27, 1973, at 15:18 Moscow Time, Vehicle No. 37 lifted off from Site 1 in Tyuratam.

The rocket successfully inserted the spacecraft into a 193 by 248.6-kilometer initial orbit with an inclination 51.61 degrees toward the Equator, where the mission was announced to the world as Soyuz-12.

Then, during the fifth orbit, more than 15 hours into the flight, Soyuz used its own propulsion system to climb into its "operational" orbit with a perigee of 332.9 kilometers and an apogee of 347.9 kilometers. (2) (According to Western sources, the maneuver took place around seven hours after launch (50)).

In any case, these orbital parameters confirmed to Western observers that the Soyuz-12 mission was related to the civilian Salyut space station program.

Perhaps to prevent rumors about problems in orbit resulting in a very short mission, the official Soviet press made an unusual advanced notice during the first day of the flight that it would last for just two days. The published drawings also indicated that the spacecraft was equipped with a docking port with a crew transfer tunnel, giving another hint about the original role of the spacecraft as a space station crew transport.

However, as it transpired years later, the Soyuz-12 spacecraft did experience a "serious problem" with its thermal control system, STR, during the flight. (1041) The ship's ion attitude control system also worked unreliably with numerous glitches, which could not be clearly explained. (1042)

Nevertheless, in addition to trying out their new Sokol-K pressure suits and related safety gear, the cosmonauts were able to practice the scientific work that would later become a routine activity aboard Soviet space stations. Makarov photographed the Earth in six different bands of spectrum covering infrared and ultraviolet range using a LKSA portable camera, while Lazarev backed Makarov's images with a traditional camera. (50)

The Soyuz-12 mission was watched especially carefully by American specialists, who were in the process of establishing new contacts with their Soviet colleagues in preparation for the joint Apollo-Soyuz mission two years later. With little data coming from the Soviet Union, American engineers conducted independent tracking of the spacecraft in orbit. (231)

At the time, a delegation of 45 NASA specialists, including astronauts Tom Stafford and Eugene Cernan, was preparing for an unprecedented trip to Moscow.

Most importantly, the successful landing of Soyuz-12 on Sept. 29, 1973, at 14:33 Moscow Time, some 400 kilometers southwest of Karaganda, in Kazakhstan, finally put the Soviet human space flight program back into business.

The Soyuz-12 mission lasted 47 hours 15 minutes and 32 seconds.


The article by Anatoly Zak; Last update: April 2, 2024

Page editor: Alain Chabot; Last edit: September 27, 2023

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Crew of the Soyuz-12 spacecraft during training.


After the loss of the first crew of the Salyut space station during landing, pressure suits (right) were introduced for launch, landing and docking operations. Standard Pinguin suits (left) were worn during work inside the station. The equipment shown was used during the Interkosmos program in the late 1970s. Copyright © 2001 Anatoly Zak