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

In order for us to use the very best judgment possible in spending the taxpayer's money intelligently, we just have to do a certain amount of this research and development work ourselves. We just have to keep our own hands dirty to command the professional respect of the contractor personnel engaged with actual design, shop and testing work.

If we continue at this leisurly pace, we will have to pass Russian customs when we land on the moon.

In 1492 Columbus knew less about the far Atlantic than we do about the heavens, yet he chose not to sail with a flotilla of less than three ships. . . . So it is with interplanetary exploration: it must be done on the grand scale.

I have learned to use the word 'impossible' with the greatest caution.

There are flying grandfathers. But I intend to be an orbiting grandfather.

Science does not have a moral dimension. It is like a knife. If you give it to a surgeon or a murderer, each will use it differently.