About 450 people throughout the United States were polled through telephone interviews made over a three-week period starting January 6, each one lasting up to 30 minutes. The public opinion research firm Zogby International conducted the survey. Each participant had to have in a minimum annual income of at least $250,000 a year and a net worth of about $1 million to participate.

"We want to be able to know that the people we study can afford the trip," said Derek Webber, program manager for Futron Corp., a Bethesda, Md.-based firm that commissioned the survey. Webber heads the NASA-funded Analysis of Space Concepts Enabled by New Transportation study, known as ASCENT, to gauge public and private interest in space travel. The data could then be presented to investors looking to support public space tourism efforts.

Eric Anderson, president and CEO of the space tourism group Space Adventures, said one of the main pitfalls in past surveys was that they didn't include enough people who could actually afford the expensive trip into space. The Arlington, Va.- based Space Adventures booked South African Mark Shuttleworth's recent excursion to the International Space Station.

In the new study, 20 percent of those polled said they would buy a ticket for a sub-orbital hop 50 miles into space, at a cost of $100,000 for 15 minutes in space, when it becomes available to the public. About seven percent said they would be willing to plunk down $20 million for a two-week trip aboard a space station in Earth orbit. The interviews also included questions on the potential risks and health drawbacks of spaceflight and specifically detailed what the experience on both a sub-orbital and orbital mission would be like to get back accurate responses.

"Theres enough material in [this study] to tell us a lot about these people," Webber told SPACE.com, adding that some poll data remains to be analyzed.

Almost half of those surveyed told pollsters they would be more likely to take an orbital trip given the existence of a space station or facility devoted exclusively to tourism. Meanwhile, 61 percent said they would prefer the chance to train for their trips in the United States, as opposed to Russia. Space tourists Dennis Tito, and more recently Mark Shuttleworth, trained for months in Russia, the only place available today, before their trips.

Space Adventures conducted its own poll on space travel two years ago, with 2,022 participants across the United States and Canada. Although the survey focused primarily on sub-orbital flights, it found that 86 percent of those polled were interested in space travel for tourism and leisure, with 10 percent earning enough to go through with it given the chance.

"There were very clear projections that thousands of people, between 5,000 and 10,000 per year, would participate in sub-orbital space flights priced at $100,000 a flight," Anderson said. "Its a billion dollar market today."

Webber expects analysis of the entire Futron space travel study to be completed in the next month, when it will then be presented to NASA officials.

"We have all the pieces of the picture, all we have to do is assemble them," he said.