For the future, primarily, we must educate people in science, engineering, technology and math.

The energy varies with the square of the velocity, so if you need five times the velocity, that's 25 times the energy.

America can take man to the moon, and America can take men to Mars - and beyond.

In Mars, we've been given a wonderful set of moons where we can send continuous numbers of people.

I want to reach a new generation. That's why I am Twittering now. I have a BlackBerry, an iPhone and a Mac.

Absolutely the United States should lead in space, for the survival of the United States. It's inspiring for the next generation. If we lose leadership, then we'll be using Chinese capability to inspire Americans.

I believe that space travel will one day become as common as airline travel is today. I'm convinced, however, that the true future of space travel does not lie with government agencies -- NASA is still obsessed with the idea that the primary purpose of the space program is science -- but real progress will come from private companies competing to provide the ultimate adventure ride, and NASA will receive the trickle-down benefits.