Mir EO-4

Mir EO-4 was the fourth long-duration resident expedition to Mir. Aleksandr Volkov and Sergei Krikalev launched on Soyuz TM-7 with French Aragatz visitor Jean-Loup Chretien in November 1988, while physician-cosmonaut Valeri Polyakov had already been aboard Mir from Soyuz TM-6. After the Franco-Soviet Aragatz visit ended and Chretien returned with the Mir EO-3 crew, Volkov, Krikalev, and Polyakov formed the resident crew. The expedition supported a crowded handover, the December 1988 Volkov-Chretien EVA, continued research in medical, Earth-observation, and station-systems fields, and Progress cargo operations. Delays to Kvant-2 and Kristall changed the planned EVA and station-assembly work, so the crew prepared Mir for an uncrewed period rather than handing over immediately to another resident crew. Volkov, Krikalev, and Polyakov returned on Soyuz TM-7 on April 27, 1989, after loading experiment results and film for return to Earth.