Exploring Mars is a far different venture from Apollo expeditions to the moon; it necessitates leaving our home planet on lengthy missions with a constrained return capability.

During the divorce process, I lived alone and tended to get extremely down on myself.

The first footfalls on Mars will mark a historic milestone, an enterprise that requires human tenacity matched with technology to anchor ourselves on another world.

A mind concerned about danger is a clouded mind. It's paralyzing.

Anything we can do in the near future that begins to stimulate the interest of people - seeing somebody down the street have an opportunity to go into space - buoys up the whole neighborhood.

Only a large-volume market like space travel can attack the barrier of high costs.

When we can demonstrate that we can take off horizontally and put something into orbit, then we can begin to talk about increasing the amount of payload. But to say, 'I'm going to do that and put people into orbit' is a real leap.