* Flight Journal: " Soyuz 5's Flaming Return " by James Oberg

The next mission to successfully dock with the station, Soyuz 24, would vent Salyut 5's air to space and replace it due to concerns the air had become toxic.

On orbital insertion, the solar panels of the Soyuz module failed to fully deploy, thereby preventing the craft from being fully powered and obscuring some of the navigation equipment.

The version of Soyuz 7K-OK spacecraft used for the missions carried a torus shaped docking electronics equipment housing surrounding the motor assembly on the back of the service module.

As a result of the added mass of the equipment module, Volynov lost control of Soyuz 5 which began to tumble, finally stabilizing itself with the thinnest part of the spacecraft facing forward.

* Soyuz T-15, a mission to ferry equipment from Salyut 7 to Mir, which had to manually maneuver and dock to Mir.

Salyut 7 was last inhabited in 1986 by the crew of Soyuz T-15, who ferried equipment from Salyut 7 to the new Mir space station.

Soon after this, Kovalyonok and Ivanchenkov performed maintenance on the station ’ s airlock, installed equipment they brought with them in Soyuz 29 ’ s orbital module, and tested the station ’ s Kaskad orientation system.

The " Transfer Chamber " is equipped with automatic docking equipment and is used to service Soyuz and Progress spacecraft.

* Soyuz T-15, a mission to ferry equipment from Salyut 7 to Mir, which had to manually maneuver and dock to Mir.

The reentry capsule is the " middle " module of the three-part Soyuz or Shenzhou spacecraft – the orbital module is located at the front of the spacecraft, with the service or equipment module attached to the rear.

Soyuz 5 almost ended in disaster, when the reentry capsule entered the atmosphere on the wrong end – attributed to a failure of the equipment module to separate similar to that on the Vostok 1 flight.

The following month Komarov clashed with other engineers over ongoing design problems in which zero-G tests showed that the Soyuz module hatch was too small to allow the exit of a fully suited cosmonaut safely.

Komarov tried unsuccessfully to orient the Soyuz module for five hours.

As a result of the problems with the craft, the second Soyuz module which was to have carried cosmonauts to perform an extra-vehicular activity ( EVA ) to the Soyuz 1 was not launched and the mission was cut short.

When interviewed on May 17 by the newspaper Komosmolskaya Pravda, Yuri Gagarin alluded to the failure of the administration to listen to the concerns about the Soyuz module that were identified by the cosmonaut corps and that Komarov's death should teach the establishment to be more rigorous in its testing and evaluation of " all the mechanisms of the spaceship, even more attentive to all stages of checking and testing, even more vigilant in our encounter with the unknown.

These modules would have used a Soyuz propulsion module, as in Soyuz and Progress, and the descent and orbital modules would have been replaced with a long laboratory module.

To prepare, the US designed a docking module for the Apollo that was compatible with the Soviet docking system, which allowed any of their craft to dock with any other ( e. g. Soyuz / Soyuz as well as Soyuz / Salyut ).

The joint mission began when Soyuz 19 was first launched on 15 July 1975 at 12: 20 UTC, and the Apollo craft was launched with the docking module six and a half hours later.

As a result, the Soyuz reentry module fell to Earth in Orenburg Oblast almost entirely unimpeded, at about ; Komarov died on impact.

The second series of test spacecraft being a precursor to manned circumlunar loop flights used a stripped-down variant of Soyuz spacecraft, consisting of the service and descent modules, but lacking the orbital module.

The service module of the Soyuz failed to separate after retrofire, but by that point it was too late to abort.

While this had occurred on various Vostok and Voskhod flights, it was a much more serious problem for Volynov, as the Soyuz service module was much larger than the small retropack the earlier vehicles employed.

When the Soyuz started aerobraking in the upper reaches of the atmosphere, the combined spacecraft sought the most aerodynamically stable position-nose forward, with the heavy descent module facing directly into the air stream with only its light metal entry hatch at the front to protect it.

Khrunov and Yeliseyev put on their Yastreb (" hawk ") suits in the Soyuz 5 orbital module with aid from Commander Boris Volynov.

Khrunov went out first, transferring to the Soyuz 4 orbital module while the docked spacecraft were out of radio contact with the Soviet Union over South America.

They closed the Soyuz 4 orbital module hatch behind them, then Soyuz 4 Commander Vladimir Shatalov repressurized the orbital module and entered to help Khrunov and Yeliseyev get out of their suits.

Three days later, the Soyuz 10 crew attempted to dock with it, but failed to achieve a secure enough connection to safely enter the station.

Although it failed to reach the Moon, the Soyuz went on to be repurposed from the centerpiece of the Zond lunar program to the people-carrier of the Salyut space station program, the Mir space station, and the International Space Station.

The Soyuz 18 crew were the back-up crew for the failed Soyuz 18a mission, carried out that mission's objectives, and continued the work of the previous Soyuz 17 crew.

With information released after the breakup of the Soviet Union, historians began to reassess the presumed " success " of the mission: the early Soyuz missions had indeed been intended to perform a physical linkage between two spacecraft, and in this they had undeniably failed.

The previous three Soyuz flights were also dock attempts but all had failed for various reasons.

The crew of Georgi Shonin and Valeri Kubasov were meant to take high-quality movie photography of Soyuz 7 and Soyuz 8 docking but the rendezvous systems on all three spacecraft failed.

While the Soyuz crew was able to achieve " soft dock " with Salyut though the " probe and drogue " docking mechanism, it failed to achieve " hard dock " by securing the docking collar – it was not possible for the crew to enter the station safely.

Two of these missions, Soyuz 10 and Soyuz 33 were intended to dock with Salyut space stations, but failed to do so.

Several months earlier, the first mission to the Salyut, Soyuz 10, had failed to successfully dock with the station.

The cosmonauts boarded Soyuz 21 but as Volynov tried to undock from the station, the docking latches failed to release properly.

Only one of the three intended crews successfully boarded and manned the station, brought by Soyuz 14 ; Soyuz 15 attempted to bring a second crew but failed to dock.

One other spacecraft, Soyuz 15, came within 40 meters of the station, but failed to dock due to a malfunctioning rendezvous system.

They were intended to be the second crew to man Salyut 3, but they failed to dock, after their Igla rendezvous system on their Soyuz spacecraft malfunctioned, and they were unable to manually dock.

Following the failed docking of Soyuz 15, it was decided that the Igla docking system needed significant modifications.

A third Soyuz mission attempted to visit the station, but failed to dock, whilst a fourth mission was planned but never launched.

Kovalyonok, who was aboard the failed Soyuz 25 mission to Salyut 6, became the first person to visit the same station twice.

Launched 18 December 1973, the Soyuz 13 crew of Klimuk and Lebedev performed some of the experiments intended for the failed Salyut space stations from the previous year.