Soyuz 21 was launched July 6, 1976
and was the first mission to the Salyut 5
space station. The crew were in space for nearly 50 days working on the military experiments but it was but short after the crew developed psychological
On board were Boris Volynov and Vitali Zholobov. Their callsign for the mission was Baikal (Baikal - lake in Siberia).
Their first problem occurred during the docking. As they were approaching the station the Igla Rendezvous System failed. They managed to dock successfully using the manual backup. This was a blow to the Russians who had done much to try and improve the system which was an integral part of a mission being a success.
Salyut 5 was much the same as Salyut 3 in size and appearance. It featured several several types of cameras that were used for "remote sensoring" (read photographic reconnassiance).
They also made observations of aquarium fishes they had launched with the station to see how they reacted to microgravity. There was some solar observation with telescopes in varying wavelengths and a TV conferences with Russian school children.
The mission was cut short after Volynov requested they return to Earth due to the deterioating condition of Zholobov. He was suffering from space sickness and both had some psychological problems.
They landed 200 km southwest of Kokchetav, Kazakhstan. The official Soviet finding was that they had become emotional, not followed their physical training, and developed an unreasonable desire to return to earth. Local newspapers reported that the cosmonauts were suffering from 'sensory deprivation'.
Another cause of the problem was speculated to be a toxic gas of some sort in the station. The crew had complained of a bad smell. It was suspected that this could have come from a leak of fuel into the crew compartments. The next mission carried up equipment that could be used to completely change the stations air supply.