Soyuz 27 carried Salyut 6 EP-1 mission to the Salyut 6 space station. The mission began on January 10, 1978, 12:26:00 UTC, launching Commander Vladimir Dzhanibekov and Flight Engineer Oleg Makarov into orbit. They docked with the station the next day. During their 5-day stay on the station, crew performed various scientific and technological experiments. EP-1 crew swapped vehicles with the Soyuz 26 (EO-1 expedition) crew, which allowed for a longer stay in orbit for EO-1.
EP-1 crew returned in the Soyuz 26 spacecraft, landing safely back on Earth on January 16, 1978, 11:24:58 UTC.