When we're on the space station, we orbit the Earth 16 times per day, which means we're constantly moving to and away from the sun. From light to shadow, the temperature swings by 300 degrees. Of course we're protected by the gear we wear, but you can definitely feel this temperature change.

The blackness of space was a big shock to me. It is a deep, three-dimensional, oily blackness. You can feel the distance.

In 2009 I went up on the space shuttle. I was in space for 16 days and docked at the space station for 11 days. The entire crew did five space walks, of which I was involved with three of them. When you're doing a space walk, you always have a buddy with you. It's a very dangerous environment when you're doing a space walk.

We have to be plumbers, electricians, construction engineers, or workers, on the space station, but at the same time running a laboratory, being scientists, being the best laboratory assistants we can be. It's all in a bundle; it's very exciting, it's a lot of fun.

I had a great career. I have no reason to complain. It's the way it goes in nature. You slow down. And I believe I lasted a lot longer than a lot of people.

If you don't like something, change it. My parents expected me to stay in my office job as an administrator at the Co-op because I'm disabled, but I said no and changed my whole life.

There are real tricks to getting a job that I just don't like or understand - it feels too close to pandering. I've tried it, but it doesn't work.

I lost my computer business when I was 29 because I gave credit to firms I didn't investigate. I lost my house and had to move back in with my parents and then I lived in an office for six months.