Soyuz 9 was a June, 1970, Soviet crewed space flight. The two-man crew of Andriyan Nikolayev and Vitaly Sevastyanov broke the five-year-old space endurance record held by Gemini 7, with their nearly 18-day flight. The mission paved the way for the Salyut space station missions, investigating the effects of long-term weightlessness on crew, and evaluating the work that the cosmonauts could do in orbit, individually and as a team. It was also the last flight of the first-generation Soyuz 7K-OK spacecraft, as well as the first crewed space launch to be conducted at night. In 1970, Soyuz 9 marks the longest crewed flight by a solo spacecraft.

Andriyan Grigoryevich Nikolayev was a Soviet cosmonaut. In 1962, aboard Vostok 3, he became the third Soviet cosmonaut to fly into space. Nikolayev was an ethnic Chuvash and because of it considered the first Turkic cosmonaut.