What keeps me up at night? Probably most, thinking about the future for my kids. It sounds kind of funny, but not so much what they're going to do, but how as a parent, how my wife and I as parents, how best we should prepare them for the world. And I know everybody does this, I think everybody stays up at night thinking about the best thing for their kids, and astronauts are no different.

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 expense of getting into space is the rocket launch, the rocket itself. Rocket's right now, commercial rockets cost probably somewhere between $50, or $120, or $150 million per launch. And those are all expendable. That is, you've got to buy a new rocket for each launch. So, that really is the critical part. If there was some kind of really, a revolutionary breakthrough and the price of rockets fell by an order of magnitude, I mean, just imagine what that would do as far as getting access to more ordinary people.

If you increase the number of rockets you build and you buy, then it's the scale of the economy, the price is going to come down. It may not come down in order of magnitude, but if several commercial ventures start being successful and there becomes a bigger market for these rockets, the price will naturally come down a bit. That's why I think Excalibur Almaz, we're a little bit unique in that we don't look at our so-called competition with disdain, we want them to succeed and it needs to have more than one player. Even if we are successful, we couldn't handle the entire market ourselves.

I attended a big human space flight conference in Beijing and I was going as myself. And really, there weren't any NASA astronauts there, I was the only so-called American Astronaut there. We had astronauts from most of the other countries, certainly from Russia, from France, from Japan, several other countries, but it was a little bit odd because here we are at an international gathering of a lot of astronauts and I'm talking about somewhere upwards of 30 or so astronauts, and I'm the only American. And I wasn't even there in an official capacity.

The neatest thing about research and science is we don't necessarily know what's going to come down the pike. We think we know what we're working on. Oftentimes, discoveries are made when you're trying to discover something else. You end up accidentally discovering a different thing. So, one of those things might happen that enable us to have more efficient rockets.

As commander I was responsible for the overall success of the mission, and so I had to know at least a little bit about everything.