Tested spacecraft systems and designs, manoeuvring of space craft with respect to each other in orbit, conducted scientific, technical and medico-biological experiments in group flight. Was to have docked with Soyuz 7 and transferred crew while Soyuz 6 took film from nearby. However failure of rendezvous electronics in all three craft due to a new helium pressurization integrity test prior to the mission did not permit successful rendezvous and dockings. Recovered October 18, 1969 10:19 GMT.

As the day begins, Soyuz 6 and 7 are out of range of tracking stations and there is little activity at the cosmodrome. Kamanin awakes the Soyuz 8 crew at 07:30. The state commission meets at Area 31 at 10:30. At 13:05 the crew meets the commission again at the base of the rocket and declare themselves ready for flight. The crew takes the lift to the rocket. 15 minutes later they report a problem - one of three spokes of the wheel used to close the airlock has a crack in it. There is the possibility of decompression if they could not get the hatch closed in space, but Mishin decides to launch anyway. Launch proceeds normally, and the spacecraft begin their rendezvous manoeuvres.

With all the crews in orbit, the military and engineering teams prepare to fly from Tyuratam to the tracking station at Yevpatoriya. All is normal aboard all three spacecraft. The Svinets experiment has been fully completed. The teams board an Il-18 for the five-hour flight to Yevpatoriya. Mozzhorin and Efimov return to Moscow with Afanasyev, Mishin, and 70 other specialists.