It's been one of the greatest challenges that ever came along in my life; it was one of the more difficult things to do.

The way I see it, what is going to come out of the moon activities is a respect for U.S. leadership.

The leader of an Earth organization who makes a commitment to history - of humans living on Earth, to begin permanent settlement/occupation of not the moon, but of another planet - this leader will have a legacy for history that will supersede Columbus, Genghis Khan or almost any recognized leader.

My first biography written in '73 was not 'Journey To The Moon.' It was 'Return To Earth.' Because for me, that was the more difficult task - disappointment.

Exploration is wired into our brains. If we can see the horizon, we want to know what's beyond.

What comes after the moon? I think you can guess: Mars.

I suggest that going to Mars means permanence on the planet - a mission by which we are building up a confidence level to become a two-planet species.