One more thing about John Carmack- he not only writes software for rocket launchers; he also designs, builds and launches rockets!

In his spare time, and with his not inconsiderable wealth, he's actually working on a rocket that can launch passengers to an altitude of about 100km or so, which is generally recognized as being 'in space', and return them safely to earth.

Testing so far has been restricted to about 30 feet (and that was when the throttle got stuck ;-), primarily because he hasn't got a launch licence yet- but he's working on it.

The vehicle he is designing is computer controlled and is capable of hovering. The fuel of choice is hydrogen peroxide, because it is a monopropellent but he is experimenting with different fuels, including reacting hydrocarbons with it.

Personally, I think if he can start small and build up from there, he stands a good chance of ramping up to full-on orbital space tourism! I wish him well.