The term 'defunct Soviet space station' refers to the MIR space station, which was a modular space station that operated in low Earth orbit from 1986 to 2001. It was the first modular space station and was assembled in orbit from 1986 to 1996. The station was operated by the Soviet Union and later by Russia. It was visited by astronauts from many countries, including the United States, Japan, and Germany. The station was eventually de-orbited and burned up in the atmosphere in 2001.