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Soyuz-4 and Soyuz-5 dock in orbit

On Jan. 16, 1969, the Soyuz-4 and Soyuz-5 met up as planned and conducted a picture-perfect docking at 11:20 Moscow Time, during the 34th revolution around the Earth for the Soyuz-4 and the 18th orbit for Soyuz-5.

Previous chapter: Soyuz-5 lifts off

As planned, during the 21st orbit of the mission (since the launch of Soyuz-4), Volynov conducted a manual orbit correction to bring Soyuz-5 into position for a rendezvous. The maneuver delivered 2.4 meters per second in velocity change.

After the correction, Vasily Mishin recorded the followed orbital parameters:

(774)

The orbit change was then announced by the official Soviet press in a statement dated 19:00 Moscow Time on January 15. Still, there was no word about the imminent rendezvous between the two spacecraft. The official update only said that cosmonauts on Soyuz-4 and Soyuz-5 had had a rest period from 20:00 Moscow Time on January 15 until 04:00 in the morning on January 16. Shatalov apparently slept in the Habitation Module, BO.

January 16: They finally meet

According to Kamanin, on January 16, at 09:00 Moscow Time, technical managers held a meeting at the NIP-16 ground station in Crimea, and apparently confirmed that both ships were in great shape. (774) Soon thereafter, the USSR issued another public update on the mission. It said that during its 32nd orbit, Soyuz-4 had conducted an orbit correction maneuver under manual control, placing the spacecraft into a 253 by 201-kilometer orbit. Since the declared apogee almost matched the one that had been previously announced for the Soyuz-5, it could be considered the most signifcant clue to date that the two ships were on a rendezvous path.

According to Yeliseev, Soyuz-5 also performed several orbit correction maneuvers on the morning of January 16. Some 20 minutes after the final maneuver of Soyuz-5, the distance between the two spacecraft was supposed to be reduced to just 10 kilometers, allowing the activatation of the automated rendezvous system on both ships.

The "Poisk" (search) signal lit up on Shatalov's control console inside Soyuz-4. A minute later, the "Zakhvat" (home-in) signal was also on.

Around the same time, the cosmonauts were able to establish direct radio communications between Soyuz-4 and -5.

On Jan. 16, 1969, at 10:37 Moscow Time, Soyuz-4 began an automated rendezvous with Soyuz-5. From that point, crew members aboard Soyuz-5 went quiet not to interrupt Shatalov's reports to mission control. (849)

At 10:47:55 Moscow Time, the spacecraft was just one kilometer away from its target, as it was zeroing in on Soyuz-5. (774)

When the distance between the two ships was reduced to 800 meters, Yevgeny Khrunov, suddenly exclaimed "Here it is," showing his crew mates a dark dot that appeared to be standing still relative to the moving clouds in the background. "See it," somebody radioed to the ground. Soon, the dot grew into the shape of a spacecraft and the cosmonauts aboard Soyuz-5 could see the extended solar panels and a light beacon on the approaching Soyuz-5.

As originally planned, over the final 100 meters Shatalov piloted Soyuz-4 manually, while Volynov maintained Soyuz-5 in the correct orientation.

However, according to recollections by Volynov, at a distance of 30 meters, the ships were still over Africa and out of range of ground control stations, so he and Shatalov maintained station-keeping, until mission control confirmed that it had begun receiving TV images from orbit. (850)

The pair conducted a picture-perfect docking around 11:20 Moscow Time.

Inside the spacecraft, the cosmonauts felt some jolt and saw the "mekhanichesky zakhvat" (mechanical capture) sign lighting up on the control console. After a few minutes of slow relative movement between the two ships, hooks on the docking port finally closed, completing the hard mating.

The cosmonauts checked the pressure inside the spacecraft, the status of various systems and propellant supplies — everything checked out well.

According to recollections by Kamanin, during the entire rendezvous process, mission control had little to do but to monitor the smooth operations via telemetry, complemented by a TV broadcast from orbit and Shatalov's confident commentary. (820)

The docked ships formed a 12,924-kilogram stack in orbit, which the Soviet press declared to be the first experimental station in space. (52)

Next chapter: Cosmonauts "spacewalk" from Soyuz-5 to Soyuz-4

The article and illustrations by Anatoly Zak; Last update: January 16, 2019

Page editor: Alain Chabot; Last edit: January 16, 2018

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The Soyuz-4 as seen from Soyuz-5 during the rendezvous.