“It is commonly believed that man will fly directly from the earth to the moon, but to do this, we would require a vehicle of such gigantic proportions that it would prove an economic impossibility. It would have to develop sufficient speed to penetrate the atmosphere and overcome the earth’s gravity and, having traveled all the way to the moon, it must still have enough fuel to land safely and make the return trip to earth. Furthermore, in order to give the expedition a margin of safety, we would not use one ship alone, but a minimum of three … each rocket ship would be taller than New York’s Empire State Building [almost ¼ mile high] and weigh about ten times the tonnage of the Queen Mary, or some 800,000 tons.”–Wernher von Braun, the father of the Apollo space program, writing in Conquest of the Moon