One good test is worth a thousand expert opinions.

It takes sixty-five thousand errors before you are qualified to make a rocket.

By the year 2000 we will undoubtedly have a sizable operation on the Moon, we will have achieved a manned Mars landing and it's entirely possible we will have flown with men to the outer planets.

All one can really leave one's children is what's inside their heads. Education, in other words, and not earthly possessions, is the ultimate legacy, the only thing that cannot be taken away.

In this age of space flight, when we use the modern tools of science to advance into new regions of human activity, the Bible... remains in every way an up-to-date book. Our knowledge and use of the laws of nature that enable us to fly to the Moon also enable us to destroy our home planet with the atom bomb. Science itself does not address the question whether we should use the power at our disposal for good or for evil. The guidelines of what we ought to do are furnished in the moral law of God.

My friends they were dancing here in the streets of Huntsville when our first satellite orbited the Earth. They were dancing again when the first Americans landed on the Moon. I'd like to ask you, don't hang up your dancing slippers.

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