Sergei Konstantinovich Krikalev is a Russian mechanical engineer and former cosmonaut. He is a veteran of six spaceflights, including two long-duration missions to Mir, two short-duration missions aboard NASA's Space Shuttle, and two long-duration missions to the International Space Station (ISS). On STS-60, he became the first Russian cosmonaut to fly on the Shuttle, and on STS-88, he helped connect the first Russian and American ISS segments—becoming, alongside mission commander Robert Cabana, one of the first people to enter the station. He later joined the ISS's first long-duration crew, Expedition 1, and returned as commander of Expedition 11.
Krikalev is sometimes referred to as the "last Soviet citizen," having been aboard Mir during the dissolution of the Soviet Union.