Stock Photo - Onboard the Base Block Module of Russia's Mir Space Station, astronauts Shannon W. Lucid and Ronald M. Sega, payload commander, discuss final activities between the STS-76 and Mir-21 crews as cosmonaut Yury I. Onufrienko (center) listens. Yury V. Usachev (out of frame) is Mir-21 flight engineer. The Space Shuttle Atlantis docked with Mir on March 23, 1996, and remained linked until March 28, 1996. Lucid was in the process of transferring from STS-76 to the Mir-21 crew, which thereby grew from two to three members. She will remain aboard Mir for approximately 140 days.