Floyd could imagine a dozen things that could go wrong; it was little consolation that it was always the thirteenth that actually happened.

Sometimes a decision has to be made by a single individual, who has the authority to enforce it. That's why you need a captain. You can't run a ship by a committee-at least not all the time.

One orbit, with a radius of 42,000 kilometers, has a period of exactly 24 hours. A body in such an orbit, if its plane coincided with that of the Earth's equator, would revolve with the Earth and would thus be stationary above the same spot on the planet. It would remain fixed in the sky of a whole hemisphere ... [to] provide coverage to half the globe, and for a world service three would be required, though more could be readily utilized. (1945) [Predidicting geosynchronous communication satellites]

Many, and some of the most pressing, of our terrestrial problems can be solved only by going into space. Long before it was a vanishing commodity, the wilderness as the preservation of the world was proclaimed by Thoreau. In the new wilderness of the Solar System may lie the future preservation of mankind.

In this universe the night was falling; the shadows were lengthening towards an east that would not know another dawn. But elsewhere the stars were still young and the light of morning lingered; and along the path he once had followed, Man would one day go again.

They will have time enough, in those endless aeons, to attempt all things, and to gather all knowledge... no Gods imagined by our minds have ever possessed the powers they will command... But for all that, they may envy us, basking in the bright afterglow of Creation; for we knew the Universe when it was young.

A faith that cannot survive collision with the truth is not worth many regrets.