We always thought the living Earth was a thing of beauty. It isn’t. Life has had to learn to defend itself against the planet’s random geological savagery.

Space is what stops everything from happening in the same place.

At the present rate of progress, it is almost impossible to imagine any technical feat that cannot be achieved - if it can be achieved at all - within the next few hundred years.

Before the current decade ends, fee-paying passengers will be experiencing suborbital flights aboard privately funded vehicles. . . . It won't be too long before bright young men and women set their eyes on careers in Earth orbit and say: "I want to work 200 kilometers from home-straight up!"

Any path to knowledge is a path to God-or Reality, whichever word one prefers to use

It may be that the old astrologers had the truth exactly reversed, when they believed that the stars controlled the destinies of men. The time may come when men control the destinies of stars.

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]