I think in the long run the money that s been put into the space program is one of the best investments this country has ever made . . .This is a downpayment on the future of mankind. It's as simple as that.

A precondition for being a science fiction writer other than an interest in the future is that, an interest - at least an understanding of science, not necessarily a science degree but you must have a feeling for the science and its possibilities and its impossibilities, otherwise you're writing fantasy. Now, fantasy is also fine, but there is a distinction, although no one's ever been able to say just where the dividing lines come.

In all the universe there is nothing more precious than mind.

Using material ferried up by rockets, it would be possible to construct a "space station" in ... orbit. The station could be provided with living quarters, laboratories and everything needed for the comfort of its crew, who would be relieved and provisioned by a regular rocket service. (1945)

Religion is a byproduct of fear.

I can never look now at the Milky Way without wondering from which of those banked clouds of stars the emissaries are coming. If you will pardon so commonplace a simile, we have set off the fire alarm and have nothing to do but to wait. I do not think we will have to wait for long.

The future is not to be forecast, but created.