I do a lot of running and hiking, and I also collect stamps - space stamps and Olympics stamps.

There's a huge amount of pressure on every astronaut, because when you get right down to it, the experiments that are conducted on a space flight, or the satellites that are carried up, the work that's to be done, is important and expensive work, and you are up there for a week or two on a Space Shuttle flight. The country has invested a lot of money in you and your training, and the Space Shuttle and everything that's in it, and you have to do things correctly. You can't make a mistake during that week or two that you're in space.

I never went into physics or the astronaut corps to become a role model. But after my first flight, it became clear to me that I was one. And I began to understand the importance of that to people. Young girls need to see role models in whatever careers they may choose, just so they can picture themselves doing those jobs someday. You can't be what you can't see.

It was hard to become an astronaut. Not anywhere near as much physical training as people imagine, but a lot of mental training, a lot of learning. You have to learn everything there is to know about the Space Shuttle and everything you are going to be doing, and everything you need to know if something goes wrong, and then once you have learned it all, you have to practice, practice, practice, practice, practice, practice, practice until everything is second nature, so it's a very, very difficult training, and it takes years.

Once you are assigned to a flight, the whole crew is assigned at the same time, and then that crew trains together for a whole year to prepare for that flight.

We can see cities during the day and at night, and we can watch rivers dump sediment into the ocean, and see hurricanes form.

I slept just floating in the middle of the flight deck, the upper deck of the space shuttle.