Soyuz T-12 (also known as Salyut 7 EP-4) was the seventh crewed spaceflight to the Soviet space station Salyut 7. The name "Soyuz T-12" is also the name of the spacecraft used to launch and land the mission's three-person crew. The mission occurred in July 1984, during the long-duration expedition Salyut 7 EO-3. During the mission, crew member Svetlana Savitskaya became the first woman to ever perform a spacewalk, and the potential Buran space shuttle pilot, Igor Volk, was given spaceflight experience. Unlike many Soyuz visiting missions, the Soyuz lifeboats were not swapped, and the crew returned to Earth in the same spacecraft in which they launched.
Background
Igor Volk was a test pilot, and was planned to be the commander of the first Buran spaceflight. The rule introduced following the Soyuz 25 failure insisted that all Soviet spaceflight must have at least one crew member who has been to space before. As a result, it was decided that Volk should have spaceflight experience, and he was originally scheduled to visit Salyut 7 in 1983. The NPO Energia chief decided that the Soviets would get there first, and assembled the Soyuz T-12 crew within a month of NASA's announcement, which included Volk as previously planned.
The back-up crew lists became available to Western space analysts in 1988, and they noted that the back-up crew contained a woman, but did not contain another LII test pilot. Judging from this, it appeared that, as reasons to have the Soyuz T-12 mission, achieving the first female spacewalk was more important than gaining experience for a potential Buran crew member.