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.

When you're a little different than others, it takes a little more time to fit in. If you really want to be there, there are no ingredients you need other than effort, perseverance and teamwork.

I am definitely a little more nervous for my colleagues when I'm working at mission control than I am myself, on the shuttle.

Most astronauts are very down-to-earth people. Many of us, three-quarters, have an engineering degree, and we have a very Cartesian, rational approach to things. You don't go and get swept off your feet. That's not your job and that's not why you're hired. So if you get so mesmerized that you forget to do what you're supposed to do, whether it's to open the cargo door of the space shuttle or configure something inside, then you should not be there as a professional operator.

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.

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.

A lot of people, I think, would love to see the earth from above, wear a spacesuit. Certainly, when I was a kid, I wanted to wear a spacesuit.