WASHINGTON -- Multi-millionaire Mark Shuttleworth, the 28-year-old South African who appears destined to follow fellow millionaire Dennis Tito up to the International Space Station, bristles if you call him a space tourist.

"I don't see this as a tourism gig at all. This is the first private space program," Shuttleworth told SPACE.com in an exclusive interview. "I don't like the tourism tag because it doesn't really describe what I'm doing here."

On Wednesday Shuttleworth signed a contract with the Russian Aviation and Space Agency (Rosaviakosmos) that is intended to secure him a seat on a Soyuz taxi flight to the station in April 2002.

The contract for Shuttleworth's Soyuz trip has been officially inked, said Tereza Predescu of Space Adventures in Arlington, Virginia. The group is serving as the intermediary agent between Shuttleworth and Rosaviakosmos in organizing his space voyage.

"Some details are being clarified, but the main contract has been signed and cleared," Predescu said.

Shuttleworth said that veteran cosmonaut, Yuri Gidzenko will be the mission commander, with Italian Roberto Vittori, a European Space Agency astronaut, as flight engineer.

Now in training at Russia's Star City, Shuttleworth said he has undergone a full medical certification for his flight. A strong bond has formed between the threesome, he said. The tests were done prior to starting negotiations for his flight. "I wanted to demonstrate my willingness to do this as a cosmonaut," he told SPACE.com.

The poking and probing, zero-gravity training flights, and centrifuge spins were physically daunting experiences, Shuttleworth said. "They really threw the book at me. All of those are new experiences that push you a little step toward your goal. They all present a certain amount of apprehension, and a tremendous amount of satisfaction once you've gotten those behind you," he said.

Shuttleworth said he is spending "significant sums" on science experiments and an educational outreach campaign to be done from space. "I'm very interested in science, and believe science is the central reason for our continued exploration of space. Secondly, I want to create an opportunity for South African and African scientists to push the frontiers of medicine and science," Shuttleworth said.

Considering his upcoming space travel as the realization of a personal dream, Shuttleworth said he also wants to inspire people about science done in extreme conditions, and help spur people to careers focused on innovation in science and technology.

"So I'll be working fairly hard while up there," Shuttleworth said. On the other hand, he quickly added, sightseeing and enjoying microgravity are both on the agenda too.

How much out-of-pocket expense comes with purchasing a Soyuz seat? Estimates are in the $10 million to $20 million range.

Not divulging details, Shuttleworth said there's a figure in the contract. Other work needs to be done. In addition, there's a load of legal fees and other costs that have snuck up, he said.

"At the end of the day," Shuttleworth said, "I'm very satisfied that we've come to a reasonable price." Given the science and educational output during flight, and as a result of preparing for the sojourn, he expects the mission to create an enormous amount of value.

"As they say, price is forgotten long after the quality is remembered," Shuttleworth noted.

Regarding any fears the South African may harbor, launch and landing are obvious places "where one can get into trouble quickly," he said. "There's been a lot of scary things already in some of the training. And that's exciting."

"I've found the experience of being here, entering into these discussions, navigating the local customs and traditionsall very rewarding experiences. At the same time, in training you can become scared witless. But it's all been very rewarding so far," he said.

Shuttleworth said that he looked forward to visiting the ISS crew, now departing Earth tonight aboard the space shuttle given a successful liftoff. "We won't have a chance to meet until I arrive. Hopefully, I'll have an opportunity to communicate with them before joining their adventure," he said.

Regarding the idea of large-scale space tourism, Shuttleworth said he believed a significant market exists. "It's simply not what I'm here to accomplish," he said.

But as for eventual, ticket-in-hand, coach-class passenger space travel, "real space tourism will come when you have companies devoted to thatto service that dedicated market," Shuttleworth emphasized. "That is not going to happen on a Soyuz right now. It takes months of dedicated, complicated, and risky training. There's no way to shortcut that and be safe," he said.

Interviewed after a day of microgravity training aboard a Russian aircraft in preparation for his April takeoff, Shuttleworth said he highly recommends the experience. He has made two plane flights that perform repeated parabolic dives allowing individuals inside the craft to experience lengthy stints of free-fall.

"Right now, I'm not sure whether I should be on the ceiling or on the floor. I'm having the reverse experience that I had after my first flight. I'm actually a bit hungry."