Soyuz 15 was launched August 26, 1974
. It was to be the second mission to the Salyut 3
space station, but failed to dock after a problem with the Igla rendezvous system
. It was the 50th manned spaceflight.
On board were Lev Demin and Gennadi Sarafanov. Their callsign for the mission was Duna (Danube).
Officially the mission was "... research in manoeuvring and docking with the OPS (Salyut 3) in various modes, and development of methods for evacuation and landing from space complex in new conditions." However as the old saying goes truth is stranger than fiction.
Everything was going fine up to the 300 metres from the station. At this point the Igla (needle) rendezvous system was supposed to change to the close approach sequence. Instead it implemented the sequence that was run at 3 km from the station. The Soyuz fired its main engines and accelerated towards the station, reaching a relative speed of 72 kilometres per hour. Fortunately the system, which thought it was a couple of kilometres from the station, allowed small deviations, and so the Soyuz passed at a distance of 40 metres.
The crew still had not realised what was going on and so did not shut off the rendezvous system. In the end the Soyuz made two more kamikaze runs at the station. The ground finally realised what was going on and commanded the system off. The crew by this stage only had enough fuel to land.
They landed 48 km southwest of Tselinograd, Kazakhstan at night.
The incident caused a complete redesign of the Igla rendezvous system. This was not able to be completed before the decay from orbit of Salyut 3, and so the planned Soyuz 16 mission had to be cancelled. The spacecraft that would have flown this mission later went on to fly the Soyuz 20 mission, although it had been sitting in storage for over its two year rated life.