"When Sergey Brin ... passed on this particular seat, I took it," Charles Simonyi said during a conference call this morning, discussing his plans to return to space for a second trip.

Flight organizer Space Adventures established an "Orbital Mission Explorer Circle" for clients willing to take any seats that came available. Simonyi and Brin were members offered a spot on a spring 2009 flight to the International Space Station.

The Medina billionaire and "father of Microsoft Word" has already been back to the Russian space center, Star City, to meet with cosmonauts he became friends with during training and his previous two years ago.

"Earlier this year I visited in Star City -- visited my friends -- and frankly I felt a kind of homesickness where home would be Star City."

Simonyi said he hopes to further demonstrate the feasibility of commercial space travel, do more experiments and continue to encourage kids' interest in science and space. As a gauge of interest in his flight, Simonyi's Web site, Charlesinspace.com, received nearly 40 million visits, he said.

During a conference call organized this morning, Simonyi also read a statement from his bride, 28-year-old Lisa Persdotter, saying she supports her husband entire "in pursuit of his dream."

Simonyi said he declined to pursue a walk in space on his second trip.

"I'm not enough of an athlete to undertake that. I had a gret experience of doing a spacewalk in virtual reality in Houston, it was real fantastic. It's something I wouldn't mind doing but unfortunately it just doesn't fit into my plans and frankly my physical makeup."

People understand the cost of space travel may come down over time, but they still wonder whether they'll be physically capable of making such a trip in the future, Simonyi said, explaining that that's another goal of his in making the trips.

"Let's assume that the price comes down, people understand about prices and how they change," he said. "However they can still have doubts about whether they personally are capable of taking the apparent difficulties of space flight - the physical and mental demands of spaceflight. I think as we have more civilians fly, people that I call 'people without the right stuff' ... I'm trying to establish a new minimum requirement for going to space, and changing the perception of who can satisfy the mental and physical requirements is also an important part."

Later in the call, asked about what space travel will be like in 50 years, Simonyi said people "understand the future will be like Star Trek. Steps have to be taken or it's not going to happen."