Commander Fyodor Yurchikhin and cosmonaut Oleg Kotov of the 15th International Space Station crew docked with the orbiting laboratory at 3:10 p.m. EDT Monday to begin a six-month stay aboard.
With them is Spaceflight Participant Charles Simonyi. He is an American flying under contract with the Russian Federal Space Agency.
He will return to Earth with Expedition 14 crew members, Commander Michael Lopez-Alegria and Flight Engineer Mikhail Tyurin, on April 20. Expedition 14 launched to the station last Sept. 18.
Expedition 15 crew members were welcomed by the Expedition 14 crew, including astronaut Sunita Williams, their third Expedition 15 crew member. She launched to the station aboard the STS-116 mission of Discovery on Dec. 9. She joined Expedition 14 in progress and will provide Expedition 15 with an experienced flight engineer for the early part of its increment.
Williams, 41, is a Naval Academy graduate and a Navy commander. She flew helicopters and was a helicopter test pilot before being selected as an astronaut in 1998.
Yurchikhin, 48, is making his second flight into space. He was a member of the STS-112 crew which launched to the station aboard Atlantis on Oct. 7, 2002, with the Starboard 1 Truss. He holds a Ph.D. in economics and was named a cosmonaut-candidate in 1997.
Kotov, 41, is making his first spaceflight. He graduated from the Moscow Medical Academy in 1988, and was named a cosmonaut-candidate in 1996.
Astronaut Clayton Anderson is scheduled to replace Williams as a flight engineer during Expedition 15. Anderson, 48, holds a master's degree in aerospace engineering from Iowa State University. He was selected as an astronaut in 1998 and will be making his first spaceflight.
Two Expedition 16 crew members are expected to arrive next fall to replace Yurchikhin and Kotov.
Explore further: New NASA Van Allen Probes observations helping to improve space weather models