The current market cost for a space flight, about a week in space and about six people have gone with the Russians so far to the International Space Station; it costs about $30 to $35 million. So, it's not for the faint of heart. But our own market studies that we've commissioned as well as some public market studies all indicate that there are somewhere around 20 or so individuals every year who have both the means and the interest to do this. So, the market is definitely out there.

The ultrasound that has application not only in space for a long mission or for a mission to the Moon or Mars, but also in remote areas on the Earth. Not even just - I'm not even talking about expeditions like to the Antarctic, but just a remote area, a small town somewhere. The local doctor is not going to know everything, and so if that person can link in with a diagnostic ultrasound to the hospital in New York City through the internet, then they can do a very quick diagnosis of something that's wrong with someone that's in this remote area.

I loved flying as much as I thought I would and continue to fly aircraft.

Tinkering is something we need to know how to do in order to keep something like the space station running. I am a tinkerer by nature.

The space station mission was kind of the culmination of all of my experience of being a NASA Astronaut, so it had brought all of my previous experience into play. I had to learn the Russian language to a fluent level so that I could function as the co-pilot of the Soyuz Spacecraft that we flew up and back from the space station. And then the challenge of being the Commander of the whole expedition, a six and a-half month flight aboard the international space station. I felt the burden of the whole mission on my shoulders, which was fine, and fortunately everything did go well.

The only two countries who will be able to launch people into space will be Russia and China. I've seen the Russian technology up close and I've had a chance to look at some of the Chinese technology. It's a very high level. They have good hardware and what China lacks is operational experience. But as they gain more experience, as they fly more missions, they'll catch up quickly. The U.S. does face the possibility of losing the lead in human space flight during this period of what we call the gap.

The United States, Russia, and China are the only three countries in the world that can launch astronauts into space. Mostly in the U.S. you see some companies trying to launch private commercial people into space, but nobody's done it yet. The only private vehicle that's made it into space so far is Spaceship 1 in 2004, and that was an effort that was funded by one of the Microsoft founders, and he spent about $20 million to develop this spacecraft to do a sub-orbital flight. And it's not the same as going into orbit, but it was a huge first step.