Soyuz 25 was a Soviet human spaceflight launched October 9, 1977. It was meant to be the first mission to the Salyut 6 space stationn but failed after a problem with the docking system. On board were Vladimir Kovalyonok and Valeri Ryumin. Their callsign for the mission was Foton (Photon).
All went well right up until docking. But for some reason the spacecraft would just not hard dock. Or as the news release stated:
- "At 07.09 Moscow time today (10 October, 1977) the automatic rendezvous of the Soyuz 25 ship and the Salyut 6 station was begun. From a distance of 120 metres, the vehicles performed a docking manoeuvre. Due to deviations from the planned procedure for docking, the link-up was called off. The crew has begun making preparations for a return to Earth."
This failure resulted in a rule stating that crews had to have at least one crew member who had flown before. This resulted in the all-rookie backup crew of Aleksandr Ivanchenkov and Yuri Romanenko being paired with veteran cosmonauts for later missions.