I think a Moon base is not necessary to get to Mars, but I think it will be helpful. It would give you a chance to develop and mature some systems; long duration, deep space stuff; and you're close enough to get some help, via radio from Earth.

I was able to look out the window to see this incredible sight of the whole circle of the Earth. Oceans were crystal blue, the land was brown, and the clouds and the snow were pure white. And that jewel of Earth was just hung up in the blackness of space.

It was a texture. The blackness was so intense.

I'm proud to be an American, I'll tell you. What a program and what a place and what an experience.

Roger, Tranquility. We copy you on the ground. You've got a bunch of guys about to turn blue. We're breathing again. Thanks a lot.

Roger. We've got you, we're go on that alarm.

Buzz Aldrin doesn't think we need to go back to the Moon - that we should go straight on to Mars. I'm more on the side that says we should go back to the Moon. I think there's a lot we can utilise the Moon for scientifically.