Soyuz 31

Soyuz 31 was a Soviet crewed mission to the Salyut 6 space station. It was launched on August 26, 1978, and carried cosmonauts Valery Bykovsky and Sigmund Jähn, the first German cosmonaut.

The primary purpose of Soyuz 31 was to dock with Salyut 6 and exchange the Soyuz 29 spacecraft, which had been docked to the station since June 1978, with the newer Soyuz 31. This exchange was a standard practice, designed to ensure a fresh spacecraft was available in the event of an emergency requiring immediate evacuation. Soyuz spacecraft had a limited lifespan in orbit.

While aboard Salyut 6, Bykovsky and Jähn conducted a variety of scientific experiments, focusing on Earth observation, materials processing, and biomedical research. Some of these experiments were specifically designed by East German scientists.

Soyuz 31 returned to Earth on September 3, 1978, landing in the Kazakh SSR. However, Bykovsky and Jähn did not return in their launch vehicle. Instead, they returned in Soyuz 29, leaving Soyuz 31 docked to Salyut 6 for future crews. The mission was considered a significant achievement in international cooperation in space exploration, particularly between the Soviet Union and East Germany.