I believe in an immortal soul. Science has proved that nothing disintegrates into nothingness. Life and soul, therefore, cannot disintegrate into nothingness, and so are immortal.

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.

The same forces of nature which enable us to fly to the stars, enable us also to destroy our star.

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.

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.

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

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