Twice a resident of the space station Mir, he first flew there aboard NASA's space shuttle Atlantis, launched in June 1995, and remained on Mir until September, when he returned on the Soyuz transport vehicle. Budarin subsequently flew to Mir on Soyuz in January 1998 as a board engineer, remaining on the space station until August. He later logged over five months on the International Space Station as the flight engineer of Expedition Six, launched on Endeavour on 23 November 2002 and remaining until 3 May 2003. Budarin joined the Energiya Rocket and Space Complex in 1976 as an engineer and was selected as a cosmonaut in 1989.