Some of the most exciting space education in the country is not coming out of Washington or New York or California or even Texas. It's coming from a place in Kansas called the Cosmosphere.

Curiosity is the essence of human existence. 'Who are we? Where are we? Where do we come from? Where are we going?' I don't know. I don't have any answers to those questions. I don't know what's over there around the corner. But I want to find out.

After Apollo 17, America stopped looking towards the next horizon. The United States had become a space-faring nation, but threw it away. We have sacrificed space exploration for space exploitation, which is interesting but scarcely visionary.

Chemical propulsion is obsolete to go anywhere other than the moon.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.

Curiosity is the essence of human existence.

The countdown reached ten seconds and I could almost hear an invisible crescendo of stirring background music. 'Anchors aweigh!' Five, four, three, two, one... and we had ignition!

Some astronauts describe the routine flushing of urine into space, where the freezing temperatures turn the droplets into a cloud of bright, drifting crystals, as being among the most amazing sights they saw on an entire voyage.