WASHINGTON If public space travel is to become high-flying reality rather than down-to-earth rhetoric, serious work is needed to estimate the potential size and nature of the space tourism marketplace. Not only does that make good business sense, report tourism experts, it also assures that passengers can chalk up frequent flyer miles plying to and from Earth orbit in years to come.

As the worlds first full-fare space tourist, Dennis Tito purportedly paid $20 million for his journey to the International Space Station earlier this year. With similar cash in hand and being prepped to follow in Mr. Titos contrail is Mark Shuttleworth, a young South African-based Internet entrepreneur.

Research now underway by Geoffrey Crouch, professor and chair of tourism marketing in the School of Tourism and Hospitality at La Trobe University in Melbourne, Australia and Jordan Louviere, an expert in consumer choice modeling at the University of Technology in Sydney, Australia, underscore one central fact. Space tourism concepts run the gambit from visionary, grandiose, and fanciful schemes that may never be realized to more practical and potentially feasible ideas.

But what is sorely needed is more rigorous space tourism marketing studies, said Crouch.

"We take as a starting proposition that both public and commercial interests would be served by developing a valid, reliable and accurate way to understand and predict the demand for space tourism," Crouch told SPACE.com. "Dennis Tito was the 'tip of the iceberg' and we have no way of knowing yet with any confidence just how big the rest of the iceberg will turn out to be."

"While the current going rate for space tourism seems to be around $20 million, cost is clearly a major factor," Crouch said. But the other big customer issue that seems so far to have received very little attention concerns perceived risk and safety, he said.

NASA and the Russians, Crouch points out, have a record that provides the public with some measure of the risk they would face if traveling into space using existing transportation systems. "Private groups planning to develop new, space tourism spacecraft, however, have the added burden of demonstrating an acceptable safety record before larger numbers of space tourists line up for tickets," he said.

"Therefore, from a market development perspective, the public's perception of risk may be as important as price," Crouch said.

For public space travel to skyrocket into reality, a host of players need to cooperate. Governments, regulators, insurance industries and, of course, financial markets need to mesh their varied interests to provide the firm foothold necessary for tourist-class spaceliners to roar into orbit. Up to now, Crouch asserts, almost all studies of space tourism markets have been far too simplistic. "Investors are unlikely to fund space tourism enterprises until adequate market research studies are undertaken," he said.

Crouch and Louviere point to terrestrial space tourism, be it in the form of cruise ships packed with solar eclipse watchers, rubbernecking visitors to a space shuttle liftoff, or people marching through the doors of museums to view space exploration artifacts. Terrestrial space tourism appears to be on a growth path, satisfying at least some of the dreams of people fascinated by space, the researchers suggest.

The research team has broken the space tourism market into several categories:

• Space-lite: Camps, theme parks and other activities whereby the public obtain a simulated space experience without ever leaving the Earths surface;
• Space-lite plus: Actual near-space experiences, such as flights that permit a person to experience short periods of microgravity, or take very high-altitude supersonic "joy rides" and sightseeing trips;
• Space-medium: Actual suborbital experiences lasting for brief periods and/or very low orbit experiences lasting one or at most two to three days;
• Space-heavy: Actual orbital experiences lasting several days that might include accompanying "official" crews on missions, a residential stay in a space station, or more serious efforts that include specially-built orbiting hotels.

These categories can help bring clarity to the abstract thing called space tourism, Crouch said. Those wishing to predict demand for space tourism must deal with a constellation of potential things, each of which has its own attributes, price, risks, benefits, and other qualities, he said.

For space tourism to happen anytime soon, theres little disagreement about building the business from the ground up.

"Space tourism, starting with adventure travel, appears to be the nearest term commercial market that could justify a new transportation infrastructure development," said William Gaubatz, head of SpaceAvailable, LLC in Newport Beach, California.

Gaubatz has blueprinted a family of SpaceClipper ships, an evolutionary step-by-step series of reusable space transportation systems. For instance, ClipperDawn leads to ClipperStormer, with the larger SpaceSkimmer following. Each would be a commercial suborbital vehicle, able to carry increasing numbers of passengers while helping promote public interest in space travel.

Early "barnstorming" flights to the edge of space using suborbital craft, Gaubatz said, could lead to the orbital SpaceRider. Building and flying the SpaceClipper ship series gain experience gained in step-wise fashion how best to operate certifiably safe public passenger space vehicles, he said.

"Numerous formal and informal studies carried out over the past several years in the United States, Japan, Europe and Canada have identified the potential for a very large market for space adventure travel and tourism," Gaubatz reported at Space 2001, a symposium held recently in Albuquerque, New Mexico.

"The realization of this market is dependent on the availability of safe, affordable, routine transportation," Gaubatz said. The breakthrough to breaking the standoff between market realization and transportation availability may come from the niche market of sub-orbital tourism, he said.