It's time to open the space frontier to citizen explorers.

Unfortunately, kids are led to believe things are easier to achieve than they really are.

I'm in favor of changing the destination of humans. There are a lot of manned missions that can be done, but not in the direction of the moon.

I've led a life of such structured discipline and always had a goal in mind of knowing what I was doing, from West Point to the Air Force combat, MIT, looking for new things to study and get involved in. And then I got into the space program, and how disciplined can you get?

Space architectures capable of supporting a permanent human presence on Mars are extraordinarily complex, with many different interdependent systems.

Mars has been flown by, orbited, smacked into, radar examined, and rocketed onto, as well as bounced upon, rolled over, shoveled, drilled into, baked and even blasted. Still to come: Mars being stepped on.

Certainly, I've never wanted to live on past achievements.