The Conquest of The Moon - the moonship
Conquest of the Moon (Viking Press, 1953, Wernher von Braun, Willy Ley, Fred Whipple) describes a lunar expedition that could be accomplished with the technology of 1950. It’s the second of three books that explore the implications of Project Mars.
The Conquest of the Moon outlines a major program that’s not described in Project Mars or its technical appendix, The Mars Project: getting humans to the earth’s moon and back.
The Conquest of the Moon is often credited with inspiring people, like kids who became engineers and worked on the Apollo program. I’m a little peeved I never ran across these books as a child. They would have inspired me, too.
The book takes a science fictiony, narrative approach. I’m surprised that only Lester Del Rey seems to have noticed this. He took advantage of it in his Winston science fiction books Step to the Stars, Mission to the Moon and Moon of Mutiny.
The Moonship
The real star of this book are the moonships.
They are shockingly ugly, but the attention to detail is astonishing. For example, they specify an Oxygen-Helium breathing mixture at 8 psi, with 60% He, 40% O2. The partial pressure of oxygen would be 0.4*8 = 3.2 psi. Not coincidentally, at sea level the partial pressure of oxygen is 14.7*.21 = 3.1 psi. This lessens the possibility of the bends if there’s a sudden loss of some air pressue in the crew sphere, and the personnel sphere can have thinner walls. It would also cause the crew to speak in a high pitch, causing much mirth. In the real trip to the moon, the Apollo capsule atmosphere was pure oxygen at 5 psi.
I’ve already posted about astrogators taking readings of the earth during the very long, 33 minute, cis-lunar orbit injection burn, and the resulting 5 day Hohman transfer orbit. Everything other than steering the vehicle is done by humans. Automation is almost non-existent, with the exception of the autopilot that steers the vehicle. This is consistent with the 1940s V-2 having an electronic autopilot. Von Braun knew this much automation was necessary and possible.
The moonship is a modified version of von Braun’s Project Mars interplanetary vehicles. My 1962 printing of The Mars Project doesn’t have any realistic art of the Mars ships, but it does have this schematic diagram:
Pretty clearly related, except it doesn’t have landing legs. Von Braud did not envision the Mars ships landing. He intended them as purely interplanetary space vehicles. Von Braun loved the word “nacelle”. He used it a lot in the 1955 movie Challenge of Outer Space.
Small mysteries
Why didn’t von Braun use tiny rocket motors to orient the moonship, like the USA 1960s space program did? I can’t find much in the way of reasons for choosing small rockets, but I did find out that the International Space Station uses control moment gyroscopes for attitude control, with a rocket RCS as backup. Perhaps large, flexible, space structures like the ISS and von Braun’s moonships can’t accommodate point loads like small rockets.
As an ex-structural engineer, I’d also like to know how the loads caused by acceleration are supposed to transfer from the personnel sphere and fuel tanks into the girders, beams, and struts of the ship. The sphere and tanks are basically plastic balloons. It’s notoriously difficult to get loads in and out of such thin-skinned pressure vessels.
Above, a close up of the crew sphere’s exterior structural attachment to the rest of the moonship. There’s a ring aft of the crew sphere’s equator, with a system of diagonal structs carrying the crew sphere load into the rest of the vehicle’s girder frame.
Above, an excerpt of the crew sphere cutaway diagram. The artist drew a pretty stout equatorial ring on the outside of the crew sphere, but did not draw any structure to shear the loads out of the thin-skinned sphere and into the equatorial ring.