Cosmos 188 / Soyuz-B (the passive spacecraft - 7K-OK(P) s/n 5) was launched and inserted into orbit 24 km from Cosmos 186 / Soyuz-A. This was the spacecraft that was to have flown the Soyuz 2 manned mission in April 1967. Cosmos 186 was ordered to attempt a first-orbit automatic rendezvous and docking. Although a docking was not planned for the flight, Mishin decided to attempt it anyway. The first docking attempt failed when the active spacecraft flew past Cosmos 188 at a distance of 900 m after the system lost contact. The spacecraft set itself up for a second attempt and achieved soft-dock. However when hard-dock was attempted an excessive lateral movement led to torquing of the directional steering of the active spacecraft. The detailed interface latches and connectors of the docking rings did not join. The spacecraft had hard docked but without full latching and electrical connections.
There was also a significant over-expenditure of propellant in the docking process. Cosmos 186's rendezvous manoeuvring engine had fired 28 times with a cumulative burning time of 200 seconds. As the spacecraft come into range of tracking station IP-16, the cameras showed mission control that the spacecraft were docked, but off-axis. The earth could be seen racing below in the television images. Kamanin had opposed the fully automatic docking approach when Korolev first advocated it three to four years ago, but this success moves Kamanin to feel that Korolev was right after all. Chief Designer Armin Sergeyevich Mnatsakanian's 'little Igla' has come through. Kamanin believes that this technology will be the death of big boosters like the Saturn V or N1. It makes it possible to assemble payloads in orbit launched by smaller rockets.