This story has both some interesting and funny facts indirectly connected with the mission. But first about the mission...
Launch date April 10, 1979, landing April 12 (Day of Cosmonautics in honor of Gagarin's mission day). Mission duration 1 day 23 hours 1 min. 06 sec.
The spacecraft was supposed to dock with a Salyut-6 station and the mission was to last slightly more than 7 days.
It's important to note that this was a so-called "Intercosmos" mission.
This mission has some specialties:
The analysis of the situation by Mission Control (MCC) and a possible solution took more than a day, while the Cosmonauts spent their time in the orbital capsule. Ivanov understood that something was wrong and was mainly concerned that MCC would cancel the docking ("What about my Mission?"). But commander Rukavishnikov knew clearly that it was not a question about The Mission, but about their lives. He knew that they could not use the main engine its ignition could cause the craft to explode. He knew that there was a reserve engine, which could be used only for an emergency landing. But because both engines were very close to each other only by using it would they know whether it was OK or not. If not they would only stay alive in orbit for another few days. (This type of Soyuz has a life support reserve of not more than 7 days). All other possibilities and later MCC agreed were "science fiction" using the station to dock with Soyuz; the launch of another Soyuz with a specially designed and installed docking gear... etc.
Mid day April 12th MCC instructed the commander what to do to land. It was clear to all they must ignite the reserve engine it had to work within 90 seconds. If it did they would be able to land somewhere...if the engine works 188 seconds they might be able to make it to a designated landing area. But if the thrust was not enough?
Both sides MCC and the crew knew that if it were less than 90 seconds they would be a live satellite... for 4-6 days... Then just a satellite... MCC and the Commander did not even discuss the less than 90 seconds possibility.
MCC ignited the reserve engines and it worked 90 seconds 120 seconds 180 seconds. The Commander thought it looks like were OK? The engine worked 213 seconds and then was cut off manually by Rukavishnikov. Ivanov looked at the commander with a silent question. And Rukavishnikov told him the truth for the first time "Stare at this speck of dust floating in the air. If it goes down we live!"
It went down after several very long minutes...
The capsule landed 180 kilometers farther than the normal standard landing region.
It was the only serious and dangerous accident during the manned "Intercosmos" program. As "reimbursement" Bulgaria the opportunity to send another Cosmonaut into Space in 1988. All other Socialist countries have had only one cosmonaut in Space and now, with the collapse of Soviet Union it's immutable.
Some interesting facts to give you a better "picture" of that time and an understanding of Soviet Politics.
Initial family name of Georgy Ivanov was Zhopov what is OK in Bulgarian language. But in Russian it sounds like the word for "A-hole". Because of that at Breznev's suggestion Georgy changed his name a few days before his arrival to the Soviet Union for his training to Ivanov a very common family name in Bulgaria, as well as in Russia.