“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.”

I believe that the time has arrived for medical investigation of the problems of manned rocket flight, for it will not be the engineering problems but rather the limits of the human frame that will make the final decision as to whether manned space flight will eventually become a reality.

With our present knowledge, we can respond to the challenge of stellar space flight solely with intellectual concepts and purely hypothetical analysis. Hardware solutions are still entirely beyond our reach and far, far away.

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 only hope that we shall not wait to adopt the program until after our astronomers have reported a new and unsuspected asteroid moving across their fields of vision with menacing speed. At that point it will be too late!

One good test is worth a thousand expert opinions.

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.

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

Basic research is what I am doing when I don’t know what I am doing.

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

The rocket worked perfectly, except for landing on the wrong planet.

Our sun is one of a 100 billion stars in our galaxy. Our galaxy is one of billions of galaxies populating the universe. It would be the height of presumption to think that we are the only living thing in that enormous immensity.

A good engineer gets stale very fast if he doesn’t keep his hands dirty.

My experiences with science led me to God. They challenge science to prove the existence of God. But must we really light a candle to see the sun?

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.

Nature does not know extinction; all it knows is transformation. Everything science has taught me-and continues to teach me-strengthens my belief in the continuity of our spiritual existence after death. Nothing disappears without a trace.

For me, the idea of a creation is not conceivable without invoking the necessity of design. One cannot be exposed to the law and order of the universe without concluding that there must be design and purpose behind it all.

I feel like I have to put on for my city, because we have so many legends and so many greats.

People who know little are usually great talkers, while men who know much say little.

Dining is and always was a great artistic opportunity.

Love is the greatest virtue of the heart.

Great ambition is the passion of a great character. Those endowed with it may perform very good or bad acts. All depends on the principles which direct them.

A turbulent history has taught Chinese leaders that not every problem has a solution and that too great an emphasis on total mastery over specific events could upset the harmony of the universe.

The imagination of nature is far, far greater than the imagination of man.

Eventually, I think Chicago will be the most beautiful great city left in the world.