" I believe that this nation should commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to the earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. "

― Neil deGrasse Tyson , The Sky Is Not the Limit: Adventures of an Urban Astrophysicist