It was launched on 21 December 1987, and carried the first two crew members of the third long duration expedition, Mir EO-3.

These crew members, Vladimir Titov and Musa Manarov, would stay in space for just under 366 days, setting a new spaceflight record.

The third astronaut launched by Soyuz TM-4 was Anatoli Levchenko, who returned to Earth about a week later with the remaining crew of Mir EO-2.

[3] Titov and Manarov were members of the long duration mission Mir EO-3, and returned to Earth just over a full year later, in Soyuz TM-6.

The combined crews conducted an evacuation drill, with the Mir computer simulating an emergency.