Soyuz T-9 (Russian: Союз Т-9, Union T-9) was the 4th expedition to Salyut 7 following the failed docking of Soyuz T-8. Returned lab experiments to Earth. The next mission, Soyuz 7K-ST No.16L (Soyuz 10a), had failed to launch due to a fire.

Soyuz T-9 achieved successful docking with the station, although the mission was bracketed by the failed attempt of Soyuz T-8 and the launch pad abort of Soyuz T-10 which would follow immediately.

This is Soyuz's 66th flight, and 47th crewed flight.

The Soyuz is a Soviet crewed spaceship, developed to made crewed lunar missions. This version called 7K will fly 4 times on the giant launcher N1, and several tens of times on Proton to fly over the Moon, which will be successful during the mission Zond 4. Soyuz will become the first spacecraft to transport living beings to the Moon during the flight of Zond 5, with two turtles. Subsequently, it is adapted to low orbit and will fly on the Soyuz launcher to serve the Salyut and Mir stations and the ISS.