Lev Stepanovich Dyomin was a Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 cosmonaut who flew on the Soyuz 15

Soyuz 15

Soyuz 15 was a 1974 manned space flight which was to have been the second mission to the Soviet Union's Salyut 3 space station with presumably military objectives....

 spaceflight

Spaceflight

Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...

 in 1974. This spaceflight was intended to dock with the space station

Space station

A space station is a spacecraft capable of supporting a crew which is designed to remain in space for an extended period of time, and to which other spacecraft can dock. A space station is distinguished from other spacecraft used for human spaceflight by its lack of major propulsion or landing...

 Salyut 3

Salyut 3

Salyut 3 was a Soviet space station launched on June 25, 1974. It was the second Almaz military space station, and the first such station to be launched successfully. It was included in the Salyut program to disguise its true military nature...

, but the docking failed.

Dyomin gained a doctoral degree in engineering from the Soviet Air Force Engineering Academy and the rank of Colonel in the Soviet Air Force.

He only made a single spaceflight before resigning from the space programme in 1982 and taking up deep-sea research.

He died of cancer in 1998.