Scientific literacy is one of the underpinnings of everything I do. It's why I work with schools. It's why I teach at university. I do a lot of outreach to try and improve general scientific literacy, but the core of all scientific literacy is just literacy.

There is a sunrise or a sunset from space every 92 minutes so there is an incredible amount of beauty to see from up there.

To me, it's not about being anywhere, but being able to change my perceptions and experience something new.

If you start thinking that only your biggest and shiniest moments count, you're setting yourself up to feel like a failure most of the time.

One Chief Astronaut used to make a point of phoning the front desk at the clinic where applicants are sent for medical testing, to find out which ones treated the staff well-and which ones stood out in a bad way. The nurses and clinic staff have seen a whole lot of astronauts over the years, and they know what the wrong stuff looks like. A person with a superiority complex might unwittingly, right there in the waiting room, quash his or her chances of ever going to space.

In all of the movie portrayals, a spacewalking suit seems sort of insignificant, like a pair of shorts and a T-shirt. No one thinks much about it. But it's a spaceship, not a spacesuit, an entire life-support mechanism that's incredibly complex and cumbersome. It's very difficult to put on and off. You have to run it the whole time you are wearing it, and it redefines how you move. It's like if you put on a wetsuit and a snowmobile suit and froze yourself solid and then tried to go and do work.

As I have discovered again and again, things are never as bad (or as good) as they seem at the time.