Soyuz 39 was the 15th mission to visit the Salyut 6 space station and carried the the EP-9 crew, which visited the long-duration Soyuz T-4 resident crew. The mission began on March 22, 1981, 14:58, launching Commander Vladimir Dzhanibekov and Research Cosmonaut Jügderdemidiin Gürragchaa, the first Mongolian cosmonaut, into orbit. They docked with the station the next day. During their 7-day stay on the station, EP-9 crew conducted Earth observation, material, medical and other experiments, including cosmic radiation research. The mission concluded with a safe landing back on Earth on March 30, 1981, 11:40:58 UTC.
Low Earth OrbitSoyuz T-4 was the 14th mission to visit the Salyut 6 space station and carried the EO-6 expedition, which was the final long-duration crew for the station. The mission began on March 12, 1981, 19:00:11 UTC, launching Commander Vladimir Kovalyonok and Flight Engineer Viktor Savinykh into orbit. They docked with the station the next day. During their 74-day stay on the station, EO-6 crew conducted various experiments, and were visited by Soyuz 39 and Soyuz 40 crews. The mission concluded with a safe landing back on Earth on May 26, 1981, 12:37:34 UTC.
Low Earth Orbit