In September 1976, the representatives of the PRB, HPR, GDR, Cuba, the MPR, PPR, Rumania, Czechoslovakia and the USSR signed an intergovernmental agreement on cooperation in space exploration and usage of outer space for peaceful purposes. At the same time the Soviet Union initiated the development of the Interkosmos program, which included participation of citizens of these countries in the manned space flights onboard the Soviet space vehicles and space stations together with the Soviet cosmonauts. Of course, it was enthusiastically supported and approved by the participating countries. At the intergovernmental meeting on September 14, 1976, it was decided to implement these space flights in the period from 1977 to 1982.
It was decided to perform the space flights in two stages: the first three space flights were planned to be performed in 1978, the others were scheduled for a later period of time (1979 – 1981). The training was supposed to be carried out according to a rather simplified program, using a “cosmonaut-researcher” program instead of Soyuz flight engineer program.
The first three space flights were reserved for citizens of the GDR, Poland and Czechoslovakia – the countries that were involved in the development of equipment and experiments for the Intercosmos satellites from the very outset and that could quickly develop research programs for the astronauts.
The cosmonauts of the other member-countries were launched over the following year: the People's Republic of Bulgaria (PRB), the People's Republic of Hungary (Hungary), the Republic of Cuba, the Mongolian People's Republic (MPR) and the Socialist Republic of Romania (SRR ).
The international crews’ space flights on the Intercosmos program became a major event in the international space exploration program. The cosmonauts of socialist community performed dozens of fundamental scientific and technical experiments of practical importance during the space flights. Totally, eighteen cosmonauts from participating countries of the Intercosmos program were trained for manned space flights, there were nine visiting expeditions to the Salyut-6 space station and eight dockings with the station. One of the dockings was not implemented due to the vehicle’s prime propulsion system failure. Each representative from nine socialistic countries performed one space flight through this program.