Retain the vision for space exploration. If we turn our backs on the vision again, we're going to have to live in a secondary position in human space flight for the rest of the century.

On Apollo 11 in route to the Moon, I observed a light out the window that appeared to be moving alongside us. It was either the rocket we had separated from, or the 4 panels that moved away when we extracted the lander from the rocket and we were nose to nose with the two spacecraft. So in the close vicinity, moving away, were 4 panels. And i feel absolutely convinced that we were looking at the sun reflected off of one of these panels.

Globalisation means many other countries are asserting themselves and trying to take over leadership. Please don't ask Americans to let others assume the leadership of human exploration. We can do wonderful science on the Moon, and wonderful commercial things. Then we can pack up and move on to Mars.

I think there would be no shortage of applicants to the government astronaut corps to be settlers on the planet Mars. And I think this would be very inspiring.

When I was a little kid, we only knew about our nine planets. Since then, we've downgraded Pluto but have discovered that other solar systems and stars are common. So life is probably quite prevalent.

I came to dedicate my life to opening space to the average person and crafting designs for new spaceships that could take us far from home. But since Apollo ended, such travels were only in our collective memory.

The best way to study Mars is with two hands, eyes and ears of a geologist, first at a moon orbiting Mars... and then on the surface.