In the 19th Century people were looking for the Northwest Passage. Ships were lost and brave people were killed, but that doesn't mean we never went back to that part of the world again, and I consider it the same in space exploration.

If I wasn't doing this kind of exploration, I'd like to be doing some other kind of exploration. It might be more risky, or less risky, but, in the business of exploration, risk is part of the territory.

It so happened that my goals kind of matched my career progression toward becoming an astronaut.

I never made a career decision based solely on my desire to be an astronaut. I attended the Naval Academy because I wanted to be a Navy pilot. I majored in math because math had always come pretty easily to me and I liked it.

I did a term at Cambridge University studying medicine, so I could potentially have followed in Mum and Dad's footsteps and become a doctor.

I get a lot of fans who deal with poor mental health. But that's the good thing about the Internet - that there are so many kids who can confide together and help each other out.

With moderate physical training, you can control anything in your body. You don't have to be an athlete to do it, and this isn't just about people with disabilities - it's about everyone. You just have to have the willpower, the mindset, and the desire to want to better yourself.

I think you can do as much damage to yourself going to the gym and running as you do good. So my mission in life is just to keep myself 'good' - in good health, as fit as I can be, a little bit of stretching, and just think positive and enjoy life.