Following the docking Yevgeni Khrunov and Alexei Yeliseyev transferred from one spacecraft to another through open space.

This is how it happened. Inside the orbital compartment the cosmonauts, helping each other, and assisted by spacecraft commander Boris Volynov, put on their space suits. Then the air-tight hatch between the re-entry capsule and the orbital compartment was locked and the latter was depressurised. The cosmonauts opened the hatch of the orbital compartment and emerged into open space one after the other. Following the instructions of spacecraft commander Boris Volynov, engineer-researcher Yevgeni Khrunov was the first to leave the compartment. Holding on to the rails in the orbital compartment he started smooth emergence. Then, gripping the transfer rail with his right hand, with his left the cosmonaut put a special back-folding rail into operation position. Using the rail as a support cosmonaut Khrunov glided out of the hatch. Holding on to the transfer rails he moved towards the coupling unit and then further to the orbital compartment of the other spacecraft which he entered feet first.

During the transfer cosmonaut Yeliseyev, halfway out of the hatch, watched carefully the actions of his colleague and maintained communication with him, ready to come to his aid if necessary. During Yeliseyev's transfer similar tasks were performed by Khrunov, who then stood inside the hatch of Soyuz-4. The cosmonauts spent about an hour in open space, during which time they performed a number of scientific experiments and observations.

As soon as both cosmonauts were inside the orbital compartment of Soyuz-4 it was pressurised. Cosmonauts Khrunov and Yeliseyev took off their space suits and occupied seats next to cosmonaut Shatalov. The total length of the linked-up flight was four and a half hours. After disengagement, Soyuz-4 with three cosmonauts aboard, continued orbital flight till 9 hours 53 minutes (Moscow time) on January 17 and landed in an assigned area on Soviet territory.

It is much easier to put on a space suit in zero-gravity conditions than on Earth, for in the former case the space suit is filled out and can be put on without any effort. The space suit is convenient, its flexible joints make possible different assembly operations in space. Ventilation and heat exchange inside the space suit ensure absence of excessive heat in the course of operations outside the spacecraft and during transfer. There was no fogging of the space suit window either.

Throughout the transfer period, reliable communication was maintained between myself and cosmonaut Khrunov, as well as between the spacecraft commanders and the ground stations.

The choice of the method of transfer - through open space rather than by means of a tunnel - was not an accidental one. The experiment was of great importance for future assembly of heavy orbital stations, outer inspection and performance of various repair and mounting operations outside the space station.