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.

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.

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

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

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

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.

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.