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

It was very successful, but it fell on the wrong planet.

In 1492 Columbus knew less about the far Atlantic than we do about the heavens, yet he chose not to sail with a flotilla of less than three ships. . . . So it is with interplanetary exploration: it must be done on the grand scale.

There is beauty in space, and it is orderly. There is no weather, and there is regularity. It is predictable. Just look at our little Explorer; you can set your clock by it-literally; it is more accurate than your clock. Everything in space obeys the laws of physics. If you know these laws, and obey them, space will treat you kindly.

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.

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.

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.