He will spend eight days onboard, completing 160 orbits of the Earth and covering 4 million miles (6.5 million km) in the process.

The return journey, accompanied by the fourteenth ISS crew already onboard, will take just two hours.

Mr Simonyi hopes the whole trip will accomplish a number of things.

"I have three goals," he said. "One of them is to advance civilian spaceflight, the second to assist space station research and the third to involve kids in space sciences."

He has started a website, charlesinspace.com, aimed at promoting his aims.

Dr Simonyi also plans to start a library on the ISS, leaving copies of science fiction novel The Moon is a Harsh Mistress by Robert Henlein and Goethe's Faust.

Learning curve

Dr Simonyi will now spend the next 5 months training for his mission at the Yuri Gagarin Cosmonaut Training Centre in Star City, Russia and at Baikonur in Kazakhstan.

Dr Simonyi plans to start a library onboard the ISS

Unlike some of his predecessors the engineer is already well qualified to undertake the mission.

He holds pilot licenses for jets and helicopters and has more than 2,000 hours of flying time under his belt.

However, he will still have to undergo a gruelling physical and technical regime to complete the mission. Throughout, he will be required to pass strict medical tests to continually monitor his suitability for the flight.

Dr Simonyi has also taken it upon himself to learn Russian and the complex systems on board the Soyuz spacecraft.

"I consider it an essential benefit of this whole undertaking to learn those things," he told the BBC News website.

"Learning about the systems is part of my engineering curiosity and makes the whole experience so much more interesting when I understand exactly what is going on and, for example, why the flight is safe."

Fantasy idea

Space Adventures has previously sent four private explorers to space.

In 2001, American Dennis Tito was the first space tourist. He was followed by South African Mark Shuttleworth the year after, and American Greg Olsen last year.

We've turned space tourism from a fantasy, into an idea, that became an industry.

Eric AndersonSpace Adventures

Iranian-born US businesswoman Anousheh Ansari became the first ever female space tourist in September this year.

She was a last minute replacement for Japanese businessman Daisuke Enomoto who failed his medical tests.

"Space Adventures has created more astronauts than 98% of nations on Earth," said Eric Anderson, co-founder of Space Adventures.

"We've turned space tourism from a fantasy, into an idea, that became an industry."

It was people like Dr Simonyi that deserved the credit for this, he said.

"It's not the dreamers, it's the doers that have created this new market."