To succeed, planning alone is insufficient. One must improvise as well.

At two-tenths the speed of light, dust and atoms might not do significant damage even in a voyage of 40 years, but the faster you go, the worse it is--space begins to become abrasive. When you begin to approach the speed of light, hydrogen atoms become cosmic-ray particles, and they will fry the crew. ...So 60,000 kilometers per second may be the practical speed limit for space travel.

Fifty years," I hackneyed, "is a long time." "Not when you're looking back at them," she said. "You wonder how they vanished so quickly.

A robot must obey the orders given it by human beings except where such orders would conflict with the First Law. [The Second Law of Robotics]

And in man is a three-pound brain which, as far as we know, is the most complex and orderly arrangement of matter in the universe.

Although the time of death is approaching me, I am not afraid of dying and going to Hell or (what would be considerably worse) going to the popularized version of Heaven. I expect death to be nothingness and, for removing me from all possible fears of death, I am thankful to atheism.

A neat and orderly laboratory is unlikely. It is, after all, so much a place of false starts and multiple attempts.