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

America's can-do spirit cast a warm glow across nations and cultures, generating more goodwill and support for our country's ideals and causes than had otherwise been possible.

We're number one on the runway.

For every winner, there's a loser. And that person didn't really need to lose. They just didn't understand the game plan.

The guys who walk on Mars are going to be historic.

We need to begin thinking about building permanence on the Red Planet, not just have voyagers do some experiments, plant a flag and claim success. Having them go there, repeat this, in my view, is dim-witted. Why not stay there?

The society of life on Mars, or the challenge of making Mars more livable, will have significant benefits on our attempts to modify and change in some ways the environment here on Earth.