Expedition 15 commander Fyodor Yurchikhin (left) assists crew mate and flight engineer Oleg Kotov while training in the Crew Systems Laboratory at Johnson Space Center. The two cosmonauts and U.S. astronauts Clay Anderson and Dan Tani will be the newest four crew members of the International Space Station next year. ((NASA))

NASA announced the next crew of the International Space Station on Wednesday as astronauts from the current crew and the space shuttle Discovery prepared for their second spacewalk.

Russian cosmonaut Fyodor Yurchikhin will command the Expedition 15 crew of cosmonaut Oleg Kotov and NASA astronauts Clay Anderson and Dan Tani, NASA said at a press briefing.

Computer software engineer Charles Simonyiisalso set to become the fifth space tourist when he travels to the station with Yurchikhin and Kotov aboard a Soyuz spacecraft in April 2007.

Yurchikhin and Soyuz pilot Kotov will replace two members of the Expedition 14 crew, who will return with Simonyi aboard the Soyuz spacecraft. The two cosmonauts will spend six months aboard the station.

Space shuttles will transport Anderson and Tani to the station later in the year. Anderson will be part of the space shuttle Endeavour's mission, targeted for launch next June. Tani will replace Anderson a few months later when he arrives aboard the shuttle Atlantis.

German Thomas Reiter of the European Space Agency will be returning to Earthafter his own six-month tour of duty finishes at the end of the 11-day Discovery mission.Replacing him will be U.S. astronaut Suni Williams.

Williams is partthe seven-person crew of Discovery, which launched successfully on Saturday night and is rewiringthe station.