Soyuz 27 was launched January 10, 1978
and was the second successful mission to Salyut 6
. It was also the first visting crew
and the first time that a crew would return to Earth
in a different spacecraft than the one they had launched in. It would also be the first time that three spacecraft were docked together. It was signaled the beginning of the Russian semi-permanent occupation
On board were Oleg Makarov and Vladimir Dzhanibekov and their callsign for the mission was Pamir (Pamir mountains).
The mission itself really only had two goals. The first was to free the aft port of the station for the Progress freighter. At that time Soyuz 26 was docked to that port after Soyuz 25 was unable to dock to the forward port but an EVA by the Soyuz 26 crew had found that there was nothing wrong with the forward port, showing that the problem was with Soyuz 25 instead. Mission Control however did not feel confident enough to just let the crew of Soyuz 26 undock, fly around the station and dock at the forward port. So instead they decided to let Soyuz 27 dock with the forward port and then land in Soyuz 26, leaving the aft port free for Progress 1.
The other goal was more to do with PR and propaganda. It was basically to have three spacecraft docked together. This would be the first time since ASTP that two crews had been in space together and the first time that both crews were in the same spacecraft together.
The launch was completely nominal and so was docking. Dzhanibekov (who was the commander) allowed the automatic system to dock the station. Even though at one point he detected that they were slightly off course he allowed the system to continue and with 7 metres to go the Soyuz corrected the slight alignment error.
They then encountered their first problem - the hatch wouldn't open. The hatch suddenly did pop free sending Makarov and Dzhanibekov backwards. The crew of Soyuz 26, Georgi Grechko and Yuri Romanenko, dove into the Soyuz and grabbed their first visitors for one month. They hugged and talked to Mission Control were Leonid Brezhnev was watching the proceedings through a live video feed from space. Among the gifts from Earth were newspapers and letters from home.
Russian society places great importance on welcoming vistors. Part of this is the eating of bread and salt, symbols of fellowship and good luck, though on the station all they had were crackers and salt tablets. They also made many toasts with vodka and cherry juice in squeeze tubes.
To test the structural integrity of the station that now consisted of three spacecraft, the four men held onto the treadmill and bounced up and down to see if the amplified the vibrations. It had been found that the resonant frequencies of the station could be created by running the station at certain speeds. The crew found that that the station was perfectly safe with three spacecraft docked.
One piece of information that the crew of Soyuz 27 didn't immediately tell the crew of Soyuz 26 was that Greckho's father had died ten days earlier. Psychologists had decided it was not in the best interests of a cosmonaut spending several months in space to have this hanging over them. Makarov and Dzhanibekov did tell Romanenko and they all agreed that was the right thing to do, though Romanenko decided that he would be the one to tell Greckho when they landed. Years later Greckho said in an interview that he also thought the decision was the right one.
The only major scientific experiment performed by the crew of Soyuz 26 and 27 was an investigation into how microgravity effected the way that protozoa cells grew. This showed that there was very little difference in the growth of the ones in space and the control group on Earth. The only difference was a slight one in the cells metabolism.
After five days at the station, the crew swapped their custom seat liners with those in the Soyuz 26 spacecraft, closed the hatch and undocked. They landed 265 km west of Tselinograd, Kazakhstan.