The 20th Expedition marks the start of six-member crews being based on the ISS. All five of the international partner agencies - from the U.S., Japan, Russia, Europe and Canada - will be represented on the orbital station for the first time.
The crew, comprising flight engineer Frank De Winne from the European Space Agency, Robert Thirsk from the Canadian Space Agency and Russia's Roman Romanenko, will lift off from the Baikonur space center in Kazakhstan on board a Soyuz TMA-15 launch vehicle on May 27.
The astronauts will join the current Expedition 19 crew, comprising Russian Commander Gennady Padalka, U.S. Flight Engineer Michael Barratt, and Japanese astronaut Koichi Wakata.
During the upcoming 180-day mission, the six-member crew will receive and unload three Russian Progress craft and a Japanese HTV-1 space freighter, conduct two spacewalks and carry out a series of scientific experiments.