Even though NASA tries to simulate launch, and we practice in simulators, it's not the same - it's not even close to the same.

I had both male and female heroes.

My background is in physics, so I was the mission specialist, who is sort of like the flight engineer on an airplane.

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.

The rockets light! The shuttle leaps off the launch pad in a cloud of steam and a trail of fire.

When the space shuttle's engines cut off, and you're finally in space, in orbit, weightless... I remember unstrapping from my seat, floating over to the window, and that's when I got my first view of Earth. Just a spectacular view, and a chance to see our planet as a planet.

Weightless is a great equalizer.