Mark Shuttleworth, 27, would become the second fare-paying tourist to make a round trip to the international station, following in the footsteps of wealthy California financier Dennis Tito, who spent about a week on the outpost in late April and early May.

Now training at the Gagarin Cosmonaut Training Center outside Moscow, Shuttleworth would fly to the station next April on a mission to deliver a new Russian Soyuz lifeboat to the outpost.

He and two cosmonauts then would return to Earth in an older Soyuz that will have been parked at the outpost for six months the orbital design life of the Russian craft.

A request to fly Shuttleworth on the so-called Soyuz swap-out mission recently was delivered to NASA officials by Russian counterparts involved in the international station program, NASA space station project manager Tommy Holloway said.

"That is being taken under consideration and a decision should be made in the next month or so," Holloway told reporters at a news briefing at NASAs Johnson Space Center in Houston.

A native of Cape Town, Shuttleworth would have to successfully complete four to six months training in both Moscow and Houston and pass all required medical exams in order to make the flight, Holloway said.

The exact requirements now are being ironed out by a multinational board NASA and its partners set up to establish training and medical criteria for all non-professional astronauts aiming to visit the station, Holloway said.

"Assuming that (Shuttleworth) meets the criteria and passes all the gates in the criteria, I dont suspect that well have any problems," the veteran NASA program manager added.

Operating out of his parents garage, Shuttleworth reportedly started a business in trading Internet security technologies with no financing. The U.S. firm Verisign bought the business out last year. Shuttleworth earned an estimated $500 million on the deal.