You can never tell when a commercial space venture will suddenly become viable.

Mars has a bit of air pressure; maybe we can build up that atmosphere to be a bit more accommodating to humans.

This has been far more than three men on a mission to the Moon; more still than the efforts of a government and industry team; more, even, than the efforts of one nation. We feel this stands as a symbol of the insatiable curiosity of all mankind to explore the unknown.

Mars, we know, was once wet and warm. Was it home to life? And what can living and learning to work on its rust-colored surface teach us about the future of our own planet, Earth? Answering those mysteries may hold the key to our future.

Going to Mars would evolve humankind into a two-planet species.

I think the public needs to be reminded just how much inspiration and intention was given throughout the world to be bold, to send human beings to the moon in the '60s and the '70s. It's important now to bring together the nations that weren't able to do it then and help them do it. We need to move forward.

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.