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!

Chemical propulsion is obsolete to go anywhere other than the moon.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

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.

As I take man's last step from the surface, back home for some time to come...I'd like to just (say) what I believe history will record. That America's challenge of today has forged man's destiny of tomorrow. As we leave the Moon at Taurus- Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind. "Godspeed the crew of Apollo 17."

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.

We leave as we came, and, God willing, as we shall return, with peace and hope for all mankind.

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.