Now retired, he was a cosmonaut. His career spanned more than two decades, beginning during the Soviet era in the late 1970s and lasting through the late 1990s. He was selected as a cosmonaut in 1978. His first mission was aboard the Salyut 7 space station in 1985, where he spent 64 days in space. His second and third missions were aboard the Mir space station, the first in 1988-1989, where he spent 151 days in space, and the second, his final mission, in 1991-1992, where he spent 175 days in space. On this later mission, he and his fellow cosmonauts arrived on the Mir as citizens of the USSR and left as citizens of Russia. After this, he trained Russian cosmonauts and foreign astronauts to work on the Mir space station and the International Space Station. He retired in 1998.