Soyuz 10 launched April 23, 1971
. It mission was to dock with Salyut 1, the first space station. The crew would stay for a month.
On board the spacecraft were Nikolai Rukavishnikov, Vladimir Shatalov and Aleksei Yeliseyev. Their callsign was Granit (Granite).
The crew were able to rendezvous successfully and everything seemed to be going right up to the moment of docking. Post-flight analysis indicated that the cosmonauts had no instrument to provide the angle and range rate data necessary for a successful manual docking.
While the Soyuz physically locked onto the station, the connection was not secure enough to allow the hatches to be opened to allow the cosmonauts inside. They were joined in their way for 5 hours and 30 minutes.
It also appeared that the hatch on the Soyuz was jammed. This meant that when they tried to undock, they couldnn't. It took the crew several attempts to release the jammed hatch impeding the docking mechanism.
The last complication on the mission came during descent. For some reason the Soyuz air supply became toxic. Rukavishnikov was overcome and became unconscious. The crew however showed no adverse affects after they were recovered.
They landed 120 km northwest of Karaganda, Kazakhstan. It was the first manned night landing of a spacecraft.
The film and photographs taken on the mission indicated that there was no problem with Salyut 1 and so Soyuz 11 was no delayed.