GOLDEN, Colo. ? Private spacewalks, customer stopovers at commercial Earth orb outposts, and public flights to the Moon are all part of Space Adventures Chief Executive Eric Anderson's vision for the growing space travel market.

Over the last decade, Space Adventures, headquartered in Vienna, Va., has offered an array of spaceflight experiences to astronaut wannabes, including: parabolic aircraft flights that provide customers short stints in a microgravity environment, simulated Soyuz launch and landing profiles via centrifuge, neutral buoyancy tank training to simulate spacewalking conditions, as well as eight-days of cosmonaut overview training that is primarily held at the Gagarin Cosmonaut Training Center in Star City, Russia.

But the big-ticket offering, and the activity that brings in big cash to the company, are private space trips to the international space station (ISS).

To date, Space Adventures has handled five customer treks to the ISS, like that of Charles Simonyi, formerly of Microsoft Corp., in April of this year; Anousheh Ansari, a high-tech telecom businesswoman in September 2006; technology entrepreneur Greg Olsen in October 2005; Mark Shuttleworth, an internet entrepreneur and the first South African to fly to space in April 2002; and Dennis Tito, a California investment guru who earned the title of the world's first paying space traveler back in April 2001.

Each person spent roughly $20 million to $25 million for their multi-day stay at the ISS, flown to the orbital outpost and returned to Earth by a three-seat Russian Soyuz spacecraft.

But the days of prices that low are over, Anderson said in a July 15 telephone interview with Space News.

"Actually, it's $30 million now. For the next couple of seats, that's the price," Anderson said. That cost hike, among several factors, is due to the falling dollar ? the ruble has appreciated some 50 percent against the dollar, he said. Another factor is simply the overall cost of inflation, he said.

"It is still the most economical and reliable, safest way to get to orbit," Anderson said of the venerable Soyuz.

Anderson announced July 18 that Space Adventures has signed two additional customers, one to be launched in fall 2008 and the other in spring 2009, though he declined to identify them.

"A spacewalk in one of those flights is a possibility, and we have people who are interested in that," Anderson said, adding that their identities likely will be unveiled later this year.

The fee for a spacewalk is $15 million on top of the $30 million base price. "One of the consequences of the spacewalk is that you get a little bit more time up there, instead of a week to 10 days, you'll probably get close to three weeks."

That private spacewalker would exit the ISS out of a Russian airlock, outfitted in an Orlan space suit, Anderson noted. "The client who does this would be doing this through the Russian Space Agency."

More seats?

Looking into the near future, Anderson said Space Adventures is talking to a number of interested parties to partake in orbital journeys. "We certainly think the market is growing and can support many flights per year over the next few years. We hope to grow from just one flight per year to two to four and beyond."

Discussions also are under way, he added, between the company and the Federal Space Agency, Roscosmos, to open up more Soyuz seats for clients. "If they want to increase capacity ? if there's a commercial reason for that, I think they certainly can," Anderson said. "We'd certainly like to see more seats become available, if possible."

Public space sojourns into Earth orbit are sure to remain a unique experience for many years to come. "There are plenty of people on Earth who haven't been out of their own country, let alone gone into space," Anderson noted. "It'll be a long time before spaceflight is boring."

Destination Moon

Also on Space Adventures travel manifest is the availability of a commercial spaceflight to the far side of the Moon. That mission concept was publicly announced by the firm back in August 2005, under the banner of a Deep Space Expeditions program. That mission would make use of a modified Soyuz spacecraft, piloted by a Russian cosmonaut with two commercial seats available priced at $100 million each. "It remains the project about which I am the most personally excited," Anderson said.

The pilot and passengers would depart Earth in a Soyuz spacecraft, linking up in orbit with an unpiloted kick stage for a boost outward to the lunar destination. The Soyuz would fly a free-return trajectory ? a boomerang course ? around the Moon.

There would be upgrades to the Soyuz communications systems, along with larger windows and a beefed up re-entry shield for the Earth return, Anderson pointed out, with those hardware add-ons making it likely the circumlunar craft would be test flown in unpiloted mode prior to commercial operations.

"It's an incredible bargain at $100 million a seat," Anderson continued. "I've had discussions over the past couple of years with a number of billionaires ? all of whom have the money ? all of whom have a very deep interest in this. I believe there's a bigger market than people might imagine," he said.

Future Deep Space Expedition missions ? lunar-orbit and lunar-surface flights ? are feasible too, Anderson said.

Space Adventures is having "serious talks" with Bigelow Aerospace, Anderson said, about using that entrepreneurial space firm's orbital habitats in the future. Two Genesis-class modules are now in Earth orbit with the company planning to evolve in coming years to larger expandable modules that can be occupied.

"It's possible we could buy an extra Soyuz and fly it to a Bigelow station. We're certainly interested in what they are doing," Anderson said.

Strictly in the black Space Adventures as a company is 10 years old. "It's not an easy business ? but it's a very important one," Anderson explained, as an avenue to foster public interest in personal space travel.

Anderson said that Space Adventures is now strictly in the black. The company was formed in 1997, growing over the years from an initial private investment of $2 million. "Now we're approaching revenues that have exceeded our investment by almost 100 times," he said.

The global travel and tourism industry is a trillion-dollar industry, about five times larger than the aerospace industry, Anderson said. The largest and fastest growing component of tourism, he said, is adventure travel. Moreover, he said, there are 20 million millionaires at present ? all prospective clientele for off-Earth travel destinations.

Harnessing that wealth to seed public space travel is analogous to those well-heeled individuals that bought the first automobiles, computers, airplanes and other high-priced items, Anderson said. The people who really benefit are the ones down the road. They get to piggyback on all the developments and improvements in technology and markets made by early adopters, he said.

Thomas Jones, a former shuttle astronaut and Space Adventures advisor, said the space tourism industry should spur less-expensive approaches to space travel overall.

"Coupled with the physical thrill is the sense that you are in some way pioneering ? you are committing yourself to a frontier, a commercial one, where your journey can make a difference and make more ambitious trips possible for future passengers. Out of such an industry should come more economical ways of getting cargo and astronauts to orbit for serious exploring, out beyond low Earth orbit. Even with the risks, it is win-win," Jones told Space News via e-mail.

Tariq Malik contributed to this article from New York.