I'm 45, and I'm still at school, essentially. Even after being assigned to the mission, I had to write a number of exams, with people commenting on my performance.

If anything, when you're up in space and you're inside a space ship, which is your home, and without which you would not survive, you know that Earth is your home. This is the only place you can return. In fact we're very meticulous. Part of our job is to maintain the spaceship. If we apply the same kind of model to Earth maybe we'd have a different outlook.

Definitely you don't become famous by doing something bad; that's a professional death sentence. You remember that whatever you do, someone will be watching, and you study all the time. It sounds terrible, but you get used to it. I'm 45, and I'm still at school, essentially.

I always call myself a space construction worker. We were only the second mission ever to go to the space station. There was nothing on board. We brought the first three tons of equipment, including some of the Imax camera stuff. We literally switched the light on to the station and walked in. It was an assembly mission.

I really believe that, in 500 years, we will still remember the International Space Station, because it will have been the first time, really and truly, that nations put a lot of money, brains, resources, and effort together to build something peacefully, and to work together for the sole and unique purpose of furthering our knowledge and bringing it back to Earth for our mutual good.

The science behind Interstellar is interesting, because some of it is absolutely real astrophysics and orbital mechanics, some of it is theoretical physics, and some of it is completely Hollywood. When a science fiction movie is based on plausible science, it's really good.

Some people will always be volunteers to explore, and it is, in my mind, a privilege.