by Paul Jay, CBC News

Former Microsoft software geek Charles Simonyi is planning to head back to space, having booked a 2nd flight aboard a Russian Soyuz rocket to the International Space Station.

At first blush, this appears to be nothing more than the story of a man with waaaay too much idle money, especially given the $25 million US price tag for the last 13 day-trip. (That works out to a cost of roughly $22 per second he was either strapped in a chair or floating around the ISS checking out the view.)

Another possibility quickly comes to mind, however: perhaps the market for $25 million jaunts to a fading space station isn't what it used to be.

Later this month video game pioneer Richard Garriot will take his trip, making him the sixth "space tourist" to pay U.S.-based Space Adventures to broker the trip with the Federal Space Agency of the Russian Federation (FSA). Space Adventures also announced an agreement with the FSA to send a private mission to the ISS in 2011.

But the next scheduled space tourist after Garriot is Simonyi, who was the fifth space tourist. Which raises the possibilty that, contrary to what we may have been led to believe, there is not a huge number of physically fit rich people with an avid interest in space travel.

There are, so far at least, six.

Given the economic situation in North America and around the world, it's not likely this number is going to grow significantly any time soon.

It makes us wonder about Richard Branson's Virgin Galactic enterprise, which is expected to launch suborbital flights in late 2009 or early 2010. So far 250 well-heeled wannabe astronauts have paid $200,000 US or put down deposits for a chance to take a flight on Spaceship Two.

It will be interesting to see, after the first rush of space enthusiasts get their taste of flying high, if anyone else will put up the cash for the trip.