The world's second space tourist began his voyage this morning aboard a Russian rocket.
"I have some nervousness and some anxiety - I am not a professional astronaut," Mr Mark Shuttleworth, a 28-year-old South African Internet millionaire, said yesterday.
Mr Shuttleworth joins Russian cosmonaut Mr Yuri Gidzenko and Italian Air Force pilot Mr Roberto Vittori on a 10-day mission to the International Space Station.
Mr Shuttleworth paid $20 million (€22.2 million) to the Russian Space Agency - a sum paid in instalments that will be complete only after the team returns to Earth.
A 161-foot Soyuz TM-34 rocketship carrying the trio lifted off at 7.26 a.m. Irish time from the same launchpad at the Baikonur cosmodrome from which the Soviet Union began the space race by sending Mr Yuri Gagarin into orbit in 1961.
This team's mission, named "Marco Polo", is to drop off a fresh Soyuz rocketship to the space station. A Soyuz is kept docked as a lifeboat and replaced every six months to keep it fresh.
AP