At the end of The Moon is a Harsh Mistress, the point is made that Luna’s best economic future is not as a farm but as a step at the top of the gravity well of an industrialized planet, IOW, a transshipment point between Earth and the Universe. But, why? If you’re trying to get someplace other than the Moon, once you get into space, why stop at the Mooon at all? What are the practical advantages to launching things from Luna over launching things from Earth, that cannot be achieved better by launching them from near-Earth orbit?
(I’m trying to think of some economically profitable reasons for Lunar colonization here. Add your own.)
If you build infrastructure on the moon, it would be cheaper to launch rockets from there than it would be from here. Or from Earth orbit, where you’d have to basically move everything from Earth to orbit, and then on. Contrast that with the Moon. Assuming you could build, say, rocket fueling infrastructure (you could make basic rocket fuel from materials on the Moon, so wouldn’t have to ship everything from Earth), it would be easier to get out of the Moons gravity well with less material than it would be from the Earth.
If you could REALLY build up the infrastructure in the future, you could, for instance, build a space elevator on the moon a hell of a lot easier than on the Earth…which would give you cheaper access to the solar system, if not the universe. Of course, building it would be the trick…
I would assume construction and habitat would be the advantages. You can dig a moonbase out of rock and it can be any size. A space-station would be limited. Also, you can use massdrivers in the asteroid belt to send raw materials to Luna, either crashing them into the surface or catching them with some kind of weenie superscience net.
The moon has 1/6th the Earth’s gravity, so moving the stuff you make off of it is much easier than bringing it from Earth.
Well, Gingrich proposed making an American lunar colony a state when it reaches 13,000 population. And if there’s that many people on the Moon at the same time, they’re not all scientists, most of them are either permanent residents or there for some kind of profitable industrial activity or both. But what economic circumstances could create that situation?
As a general answer, it’s a big fat “no”. There’s no advantage to using the Moon as a stopping point if you’re transporting stuff from Earth to (for example) Mars. It would be like if you were going from the Southern tip of Africa to the Southern tip of South America, you decided to head North East to Madagascar before heading back South and then West to the Americas. Sure, it would make your trip have a shorter break in it, but it would make the rest of the trip longer, plus the distance to Madagascar to begin with.
One alternative to superscience would be mounting some cometary ice on one end of the payload, and using a large laser on the Moon (or wherever you are sending it) to boil it away; instant rocket engine, with no fuel but ice.
If your future spacefaring society uses laser driven spacecraft of the various sorts that have been proposed, that’s a possible reason for the Moon to be a waypoint. There’s raw materials for lots & lots of lasers, no atmosphere to weaken them, and the lunar regolith ought to help as a heatsink. Although in such a scenario while the Moon might be a waypoint, the majority of craft might never touch down; they’d just get into range of the lunar laser arrays to be accelerated or decelerated.
Critically, in the book, the moon and Earth already had mass driver installations for bulk shipments. Transportation to and from was thus already assumed to be highly efficient. It makes a lot more sense for the moon’s use as a port when the Earth-Moon step of the journey is economically transparent.
The moon isn’t all that vital to interplanetary space travel. At least not in the near or even slightly distant future. This NASA plan has us getting to a near earth asteroid in 2024 in preparation for an eventual mars mission. Basically one rocket is launched and leaves a ion drive up in high earth orbit. Later on astronauts are launched and they meet up with the ion drive and head out for the destination ( Mars, Phobos or Deimos, an asteroid). On the way back the ion drive is left in Earth’s orbit and the crew splashes down.
Meh, I think lagrange points will have plenty of space for ships and ports, and the really big ships don’t need no stinking ports. Working on the moon is essentially just as difficult as working in space (except the moon is covered in super abrasive dust), and the lift off is still fuel intensive.
The only way it would ever be worthwhile is if we found some seriously energy-dense fuel material on the Moon, something that would return more than enough delta-V to justify the effort of fighting gravity to get it out. Otherwise, the guiding principle in space travel is that you avoid entering gravity wells at all cost unless they are your absolute final destination.
Using the moon as a base for space travel is a tremendous waste of energy. It’s like traveling from New York to San Diego and insisting that you’re going to drive right over the top of the Rocky Mountains rather than just driving around them. Actually it’s like insisting that you’ll drive up some mountain that isn’t even on your route, just because you like mountains.
Say we want to go to many other destinations, asteroids, space stations, moons and small planets, and we have to take cargo there. Maybe it would be more cost effective to have one ship take all the cargo out of our atmosphere and to the Moon, where smaller ships can more easily take it from there (without having to deal with the gravity or atmosphere of Earth). The Moon could be a distribution centre.
But you could use it as a refueling stop. Didn’t aircraft of yesteryear have to make more refueling stops? E.g., I think it used to be that you couldn’t fly Los Angeles->Tokyo in one hop, you had to stop in Anchorage, Honolulu, or somewhere else to refuel first. If the Moon was available as a refueling depot, you might be able to use lighter, smaller, and more nimble spaceships. Remember that when you blast off from Earth, it costs lots of fuel to launch fuel. If that fuel is already on the moon, maybe you can save some fuel. Also, with a ship with a smaller, lighter tank, you use less fuel maneuvering.
But what fuel is there fuel on the moon? If none, how do you get fuel there in any sort of cost-effective way?
Planning a stop at the moon on the way to various planets looks rather like planning a stop at the bottom of the Grand Canyon during your drive from Denver to Chicago.