What we will have attained when Neil Armstrong steps down upon the moon is a completely new step in the evolution of man.

The greatest gain from space travel consists in the extension of our knowledge. In a hundred years this newly won knowledge will pay huge and unexpected dividends.

The best computer is a man, and it’s the only one that can be mass-produced by unskilled labor.

Conquering the universe one has to solve two problems: gravity and red tape. We could have mastered gravity.

To simply dismiss the concept of God as being unscientific is to violate the very objectivity of science itself.

Get me a broom. I'll sweep my own office.

The logistic requirements for a large, elaborate mission to Mars are no greater that those for a minor military operation extending over a limited theatre of war.