Perhaps the two greatest moments of my life were standing on the moon and being outside of the room when my granddaughter was born! We tend not to remember the worst.

It's our destiny to explore. It's our destiny to be a space-faring nation.

Chemical propulsion is obsolete to go anywhere other than the moon. Three days - that's acceptable. But for Mars, we need propulsion technologies to get us there in, say, 60 days - then spend whatever length of time we want to spend and return when we want to come home.

The moon is bland in color. I call it shades of gray. You know, the only color we see is what we bring or the Earth, which is looking down upon us all the time. And to find orange soil on the moon was a surprise.

To become an astronaut, someone has to have a dream of his own to do something that he or she has always wanted to do, then commit himself to making that dream come true.

I know the stars are my home. I learned about them, needed them for survival in terms of navigation. I know where I am when I look up at the sky. I know where I am when I look up at the Moon; it's not just some abstract romantic idea, it's something very real to me. See, I've expanded my home.

Yes, I am the last man to have walked on the moon, and that's a very dubious and disappointing honor. It's been far too long.