The Soyuz TMA-13 craft, which blasted off from the Baikonur space center in Kazakhstan on Sunday, brought U.S. astronaut Mike Fincke, Russian cosmonaut Yury Lonchakov and U.S. space tourist Richard Garriott to the station.
Garriott will conduct a variety of scientific experiments during his 10-day stay on the orbiting station.
The son of U.S. astronaut Owen Garriott, the sixth space tourist to travel to the ISS made his fortune in online computer games, including the popular Ultima Online. He reportedly paid $30 million for the trip to the ISS.
The newly-arrived crew will replace Russian cosmonauts Sergei Volkov and Oleg Kononenko, while U.S. astronaut Greg Chamitoff will remain onboard until November, when he will be replaced by U.S. astronaut Sandra Magnus.
Volkov and Garriott will become the first children of astronauts to meet in space. The Russian's father, Alexander, was orbiting the Earth when the U.S.S.R. collapsed in 1991.
The new ISS crew will spend about six months in space and will carry out over 50 scientific experiments under the Russian space program, and a number of joint experiments with the European Space Agency.
In addition, the astronauts will conduct at least two spacewalks, unload two Progress M cargo spacecraft, test a new, fully-computerized Orlan-MK space suit, and receive the crews of two U.S. space shuttles.
The 18th Expedition may become the last three-man crew on board the ISS due to plans to increase the number of astronauts manning the station to six starting from spring 2009.