Suppose you came across a woman lying on the street with an elephant sitting on her chest. You notice she is short of breath. Shortness of breath can be a symptom of heart problems. In her case, the much more likely cause is the elephant on her chest. For a long time, society put obstacles in the way of women who wanted to enter the sciences. That is the elephant. Until the playing field has veen leveled and lingering stereotypes are gone, you can't even ask the question.

Astronauts will remain the explorers, the pioneers-the first to go back to moon and on to Mars. But I think it's really important to make space space available to as many people as we can. It's going to be a while before we can launch people for less than $20 million a ticket. But that day is coming.

The view of earth is absolutely spectacular, and the feeling of looking back and seeing your planet as a planet is just an amazing feeling. It's a totally different perspective, and it makes you appreciate, actually, how fragile our existence is.

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

The most important steps that I followed were studying math and science in school. I was always interested in physics and astronomy and chemistry and I continued to study those subjects through high school and college on into graduate school. That's what prepared me for being an astronaut; it actually gave me the qualifications to be selected to be an astronaut.

I was always very interested in science, and I knew that for me, science was a better long-term career than tennis.

That's something that is almost part of being human and I'm certain that will continue.