Apollo: The Race To The Moon

by Catherine Bly Cox

An even better example of Johnson’s principle is the way that Apollo came to have those gracefully rounded corners. “You’ll talk to some aerodynamicists, or some heat transfer people, and they’ll explain to you the marvelous characteristics of this rounded corner, and why it was this way, and all,” said Johnson. “That’s a bunch of nonsense. When I first laid that thing out, it was a cone like Gemini and Mercury. And there’s a good reason for it, too. That’s a nice clean separation of flow on those sharp corners.” And, imperatively, the diameter of the bottom of the spacecraft was no bigger than the diameter of the third stage of the launch vehicle that Marshall was developing—160 inches. According to Johnson, things were going fine until they got a call from von Braun saying that Marshall had reduced the diameter of the third stage to 154 inches. “We said, ‘Jesus Christ, now we can’t leave this sonofabitch hanging out over the edge like that, and we can’t change the mold lines, because that’ll cut in on the interior space.’ So we said to each other, ‘Let’s just round the corners, nobody’ll ever know the difference.’ And that’s how that command module got rounded. I don’t doubt that the rounded corners are very beneficial and all that, but that was not the driving reason when it was done.” Owen Maynard saw another benefit. He knew from experience that whatever design they submitted would inevitably accumulate weight as time went on, eventually reaching “the density of water...