Soyuz T-3 carried the first Soviet three-cosmonaut crew since 1971, when three crew had died following an air leak during the return to Earth from Salyut 1 of Soyuz 11 - they were not wearing space suits.

Subsequently, Soyuz crews wore suits on the ascent and descent but the extra weight and space penalties meant reducing the crew to two. Soyuz-T's improved performance compared with the old design meant that the change could be reversed. The improvement came in part through a slight increase in the mass of Soyuz, and partly through re-design, miniaturisation or elimination of systems.