Studying whether there's life on Mars or studying how the universe began, there's something magical about pushing back the frontiers of knowledge. That's something that is almost part of being human, and I'm certain that will continue.

Because I was a tennis player, Billie Jean King was a hero of mine.

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.

Our future lies with today's kids and tomorrow's space exploration.

I did not come to NASA to make history.

It's too bad our society isn't further along.

For a long time, society put obstacles in the way of women who wanted to enter the sciences.