Launch from the Baikonur Cosmodrome; landing 145 km north of Karaganda.

The main goals of this mission in the official version were to test spacecraft systems and designs, manoeuvring of space craft with respect to each other in orbit, and to conduct scientific, technical and medico-biological experiments in a group flight.

Soyuz 8 performed a group flight with Soyuz 6 and Soyuz 7. There was no docking, only approaching (until 500 m to Soyuz 7). The planned docking maneuver with Soyuz 7 was not accomplished (failure of rendezvous electronics). It is still not known exactly what the actual problem was, but it is often quoted as being a helium pressurization integrity test. 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. This is thought to have been pressurized with helium to provide a benign environment for the electronics. It was then jettisoned after docking to lower the mass of the spacecraft for reentry. What went wrong with the electronics on all three spacecraft is still not known.

The landing proceeds normally.