US billionaire Charles Simonyi will roar off into space aboard a Russian rocket on Thursday to make history as the first tourist to make the odyssey twice.
Hungarian-born Simonyi, who made much of his fortune developing software at Microsoft, will blast off from the Baikonur cosmodrome in the Kazakh steppe at 1149 GMT to dock with the International Space Station (ISS) two days later.
"I am very happy to stand here again and to report as a member of this excellent and experienced crew," said Simonyi, reading out a brief written report in Russian to a state commission approving the main crew before the flight.
Simonyi, a billionaire who has paid a total of $60 million for his two space trips, said he would be hanging up his space suit for good after this last trek.
"I cannot fly for the third time because I have just married and I have to spend time with my family," Simonyi, 60, who married his 28-year-old Swedish wife last November, told a pre-flight news briefing from behind a hermetic glass partition.
He will travel to ISS with Russia's Gennady Padalka and US astronaut Michael Barratt. Simonyi's wife, family and close friends will watch the rocket blast off.
Simonyi, clad in a jacket and white shirt, waved and smiled from behind a glass screen as his friends and family assembled in a Soviet-era facility in Baikonur to wish him luck.
His wife, Lisa Persdotter, kissed him goodbye through the glass and took several pictures of him. "He is in great spirit, he is very excited. He feels very privileged to be able to go to space again," Eric Anderson, president and CEO of Space Adventures which arranges space trips, told Reuters by telephone from Baikonur.
Simonyi is set to return to earth on April 7 with Michael Fincke, US commander of outgoing Expedition 18, and Russian flight engineer Yuri Lonchakov.
Russia has borne the brunt of sending crews and cargo to the multi-national ISS since the US Space Shuttle Columbia disintegrated on re-entry in 2003, killing its crew of seven.
A source in Russia's space industry told Reuters two space tourists could be launched in 2011. He gave no further details.
Space Adventures admitted its business was affected by the global financial crisis. "The number of billionaires has been cut in half," Anderson said, adding however that demand for space trips appeared to be stable for now.
"It's a very long term thing," he said. "You don't just wake up in the morning one day and decide to go to space."