I find it as difficult to understand a scientist who does not acknowledge the presence of a superior rationality behind the existence of the universe as it is to comprehend a theologian who would deny the advances of science.

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?

We can lick gravity, but sometimes the paperwork is overwhelming.

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.

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

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.

Man is not made for space. But with the help of biologists and medical doctors, he can be prepared and accommodated.