When discussing the options for colonizing
the Moon, as a stepping stone to the solar system, we’ll see that it’s not just one
small step for a man, but one giant industrial park for mankind. So today we will be looking at colonizing
the Moon, not just small bases but real colonies, and to do that we have to discuss the reasons
why we would do that. This is not our first trip to the Moon
on this channel, and won’t be our last either. We’ve visited briefly a number of times
and even did an entire episode on Moonbase Concepts. In spite of this there’s a lot of material
left to cover and we won’t do anything like exhaust it today. Our focus today is on the industrialization
of the moon, essentially the reason to colonize it with thousands or even millions of people. Not just visit, plant the flag, and head home. The Moon has a bit of a strange position
in the discussion of space travel. It remains the only place mankind has ever
visited in person, but it’s been nearly half a century since we have been there, and
only a dozen folks have ever set foot on it. It’s a big place, with a surface area larger
than any continent but Asia, so those dozen astronauts didn’t explore much of it. It’s hard to picture the moon, we
tend to envision it as a gray desert pockmarked with craters, which is true enough, but people
tend to forget that those craters range from the microscopic up to craters bigger than
all but the very largest nations and deeper than the Marianas Trench. Craters big enough to swallow whole nations
and deep enough hide Mount Everest in aren’t what we usually picture when contemplating
the Moon. We also hear a lot about lava tubes
on the moon, corridors cutting through the stone near the surface. These can range in size a lot, and the low
gravity allows them to get quite monstrous in size, looking less like a tunnel a mole
or worm burrowed, and more like something one of the sandworms from Dune made. There are thought to be lava tubes on the
Moon as wide as 500 meters and many kilometers long. We’ve got dozens of craters big enough
to house major metropolitan areas or even decent sized nations. Domed over they are big enough to be their
own mostly closed ecosystems. You could build domes that big too, an upside
of low gravity, and as we discussed in the Life Support episode, even if a panel got
shattered, air would not leak out so fast that you couldn’t repair it even if you
didn’t have some high-tech self-sealing method. That’s an important thing to remember
though, all those handy craters we can dome over exist because something big landed there,
and while ones that big are quite infrequent, the moon’s lack of an atmosphere means that
small meteors aren’t burning up before hitting and pea-sized meteors will be hitting in your
vicinity reasonably often, though not so much so as to be a normal cause of death anymore
than lightning is. If you lack the ability to make sturdy
or self-sealing domes, those underground lava tubes are a lot more appealing. Particularly since the Moon’s day-night
phase is a month long, and that light isn’t filtered of harmful radiation by an atmosphere,
so that you will tend to want artificial lighting anyway. You could get some interesting colonies in
a lava tube, since they’d tend to stretch out thin and long, akin to how we tend to
develop habitats along rivers or roads. The craters and geology of the Moon, while
fascinating, haven't proved enough justification to send more manned missions back there yet,
let alone enough to set up permanent bases, which is solidly inside our current technological
abilities, if expensive. What we are interested in today is the step
beyond that, not purely scientific and exploratory missions, nor prestige voyages to prove to
people you can land astronauts there and bring them home. That’s why the Moon holds that strange
position in space travel, because it needs to be the place where we settle two questions. First, whether or not space exploration will
be done only by robots, or if we will once again stick boots on the ground of an alien
and inhospitable world. Second, whether or not we will ever do more
than explore, but genuinely get out there and settle these places. We’ve already talked about how one
can terraform planets or even the moon, and certainly how to make comfortable habitats
on such places or orbital habitats floating in space by themselves. We know also the ultimate goal is to spread
ourselves outward to other stars and to take dead and barren alien planets and make them
homes for people, our pets and parasites, and all the other eggs we keep in this one
fragile pale blue dot of a basket. But there’s a middle ground folks
don’t spend much time on, which is what draws millions of people to the moon to live
there and work there. It’s a bit like the underpants gnomes from
South Park. They’ve got a business plan, Phase 1, collects
underpants, Phase 3, profit. Almost everybody wants to go to the
Moon, almost everybody wants us to set up bases and colonize the place, almost everybody
wants us to send out ships to explore and settle the stars. But we’ve essentially got the gnomish dilemma,
we know what phase 1 is, get people back on the Moon again and set up a base, and we know
what Phase 3 is, a profitable and growing colony on the Moon, Phase 2 is a bit of question
mark. This has gotten to the point that some
folks want to cut the Moon out of the loop entirely and go straight to Mars, or the Asteroids,
or even Venus. I’m all for doing all three and more, but
I believe that the Moon holds the potential to be the best foothold to truly getting into
space. And I think that means it needs to
benefit us in a very real and tangible way. To demonstrate that though we have
to begin by asking what benefits the Moon has. What has the Moon got that Earth lacks? What is on the Moon that the rest of the solar
system lacks? To answer this we have to get a bit
geocentric, because the first thing the Moon has that the rest of solar system lacks is
its proximity to Earth. The moon is just over a light second away,
meaning we can talk to people there real time. There’s a pause of 2.6 seconds for a message
to get there and back, but that amounts to an annoying real-time lag, nothing more. Every other object is at least light minutes
away, and constantly varies in distance. Venus is closest after that and can be as
close as 38 million kilometers, or 2 light minutes away, to 261 million kilometers, 15
light minutes away. Mars is even further off and those two, along
with Mercury, are our nearest neighbors. A ship with a power plant strong enough
to provide one-gee of acceleration constantly, so that you could walk around over the engines
like you were in normal Earth gravity, could reach the Moon in less than four hours, shorter
than many routine flights on Earth. Such a flight is very energy wasteful and
would involve flipping over halfway through to slow down, usually called ‘Turnover’,
and reaching a speed of 63 kilometers per second. That’s fast but not truly huge compared
to modern spacecraft, and something within the realm of possibility for the fission-powered
or metallic hydrogen-fueled ships we’ve discussed in the Upward Bound series. That same speed would make a trip to Mars
take more like 40 days, not 4 hours, and even a power plant able to provide a constant 1-gee
burn would take about a week, and would need to be fusion powered. What else does the Moon have that the Solar
System lacks? Well it lacks a significant atmosphere, but
so does every other body in the solar system except the four Gas Giants, Earth, Venus,
and Saturn’s moon, Titan. Of course, obviously excluding Earth, none
of those atmospheres are breathable so they offer little benefit, the lack of one is quite
handy for getting away from those places. Not so handy for landing on them though, since
you can't aerobrake and have to burn fuel to slow down. However this is the same with virtually every
one of the millions of large objects in the solar system. It also lacks much of a gravity well, making
shipping stuff out a lot easier. In fact it is so easy, especially with a lot
of the methods we discussed and will discuss in the Upward Bound series, that it actually
easier to ship material from the Moon to Earth’s Low Orbit, a distance of 400,000 kilometers,
than from Earth’s surface to our low orbit, a distance of less than a thousandth of that. Truth be told one can ship mass in from various
asteroids without spending much more fuel, but only if you don’t mind waiting years
for your shipments to arrive. The Apollo missions used the lower energy
approach, so they took a lot more than the 4 hours a continuous 1-gee burn would take,
and still they only needed 3 days. That’s comparable to a lot of normal freight
times here on Earth, faster than low-priority bulk freight in fact. Shipping in from other planets or asteroids
in the Belt could take many months or even years, especially if you’re conserving fuel. Now folks often discuss the riches to be found
in asteroids, we even did an episode on it, hypothetical dragon hoards of gold or platinum. The Moon on the other hand has a composition
pretty similar to Earth’s crust, that’s much of the reason we think the Moon was made
when some smaller planet slammed into the Earth during the early days of the solar system. That means it is quite rich in materials we
like to build out of. Plenty of Silicon and Oxygen, plenty of Aluminum
and Iron, and surprisingly rich in Titanium. Indeed there are good odds a lot of those
craters, especially the polar ones, have ice in them, and water is quite precious in the
inner solar system outside of Earth. Yet it’s worth remembering that ice isn’t
the only thing at the bottom of those craters, they were after all made from the impacts
of the same meteors and asteroids folks are talking about mining. The Moon also has its dark side, which of
course is not always dark. It gets as much light as the other side, but
what it is dark to, and doesn’t get light from, is the Earth, making it a handy place
for observatories, blocked from our glare and radio noise. The Moon is also a good place to do dangerous
or controversial biological experiments, far from life and surrounded by lifeless inhospitable
places. Ditto possibly dangerous nanotechnology experiments. We discussed setting up habitats for living
space in the craters and lava tubes a few minutes ago, but it is also a great place
for experiments with terraforming techniques for small, low-gravity places, which is most
of them. We talk a lot about terraforming Mars or Venus,
but there are thousands of small rocky bodies in our solar system we would want to mine
and make livable, and they will be far away from Earth. The Moon is close enough we can fly in emergency
supplies in enough time for it to matter, or supplies for projects we can’t make on
the spot, in-situ, all those asteroids and moons around other planets are not close enough,
even if you are pulling constant acceleration. So the Moon gives us a place to experiment
with those techniques before we head out into deep space, where resupply can take months
or years, and even advice from the experts can take hours to arrive by radio. And if you do plan to have spaceships that
can carry out near perpetual 1-gee thrust around the solar system, it helps to have
access to fuel. Hydrogen isn’t terribly common in the inner
solar system away from large gravity wells, so the ice on the moon offers one supply,
but it also has helium-3, which while harder to fuse than deuterium and tritium isotopes
of hydrogen, isn’t too much harder and also offers us aneutronic fusion, or fusion that
produces very few neutrons, which is good, particularly for spaceships, since it lets
you get away with smaller engines that need less shielding. But even without fusion power plants or ones
using Helium-3, the Moon is a great source of fuel. It’s got hydrogen, which is always a good
propellant even without fusion, and it has also got plenty of phosphorus, sulfur, aluminum,
and magnesium, which all burn well with oxygen, which is even more plentiful there. In addition, the Moon has a lot of KREEP,
which is short for Potassium, K, Rare Earth Elements, and Phosphorus, and tends to be
heavy in Uranium and Thorium. I also can’t stress enough the advantages
of low-gravity manufacturing. Zero-gee has its own advantages, but the nice
thing about low gravity is that stuff still works like we are used to. In a big smelter, denser materials still sink
to the bottom of the vat, for instance. All sorts of very expensive manufacturing
equipment that has to be built very sturdy here on Earth can be done a lot lighter and
cheaper too. When you’re building there you have no wind
or snow getting in the way and requiring sturdier buildings either, so you can build huge on
the moon quite cheaply, and while actual space-based construction can be very handy too, you can
build giant spaceships or even space stations on the Moon and tow them into orbit fairly
easily. Here we start to see the basis for a lunar
economy. Yes, tourism and science would provide a nice
subsidy. Yes, it probably has its own stockpiles of
precious metals in those craters. But the wealth there is all those things which
we actually have here on Earth, but which are far easier to move from the surface of
the Moon to anywhere near Earth than up from Earth itself. Raw mass for construction, and fuel, are what
the Moon offers to run its economy. In a way, it’s like a giant orbiting warehouse,
already conveniently pre-positioned to fuel our expansion out from Earth. Still a bit of a Catch-22 though. To make the moon profitable that way, you
have to be expanding out into space. One has to ask what space has to make it profitable? Yes the moon, if industrialized, gives us
all the materials we need to expand into the solar system, yes it gives us lots of practice
living in space on airless rocks, but how are we to get to Phase 3, profit, when that
relies on supplying all the materials for space expansion, we do need profit elsewhere
in the solar system to drive that on the moon. That though, we can gloss over for today,
because I still want to discuss Phase 4, what comes after that solar expansion, and how
it can profit us closer to home. The Moon often gets treated as the gateway
to space, but tends to get ignored afterward. When we’re discussing terraforming other
planets in our system and elsewhere, the Moon is always some place vaguely referenced as
having a colony on it, it becomes a footnote, historically important but no longer useful. We’ve talked a lot about how to get folks
and material off Earth cheaper, so we didn’t need to import stuff from the Moon to orbit,
but almost all those same tricks work on the Moon just as well or better. It’s very easy to build a mass driver or
skyhook or even space elevator on the moon. A rotating skyhook, a rotovator, could spin
right down from orbit and snatch cargo right off the ground and toss it into orbit, even
right back to Earth. Because the Moon rotates on its axis far slower
than Earth, once a month not once a day, space elevators there need to be longer, but don’t
require any super-materials to build, we could manufacture one today. The low gravity and lack of wind make tall
structures quite easy to build, that same low gravity makes excavating and mining much
easier too, but you don’t need a supertall building for a mass driver because there is
no atmosphere to rise above. Indeed with no oceans to cross, and no existing
structures or borders, one can wrap a mass driver all the way around the Moon. You don’t need a vacuum tunnel around it
either. This makes it far cheaper, just a railroad
essentially, letting you build up some very impressive speeds before letting go of the
track and flying off into space. All of which let’s you ship material back
to Earth much cheaper than up from Earth. Now why do I keep emphasizing back to Earth? Isn’t the point to use the Moon to get things
away from Earth? Well, yes and no. We often give a motivation for space travel
being to find new places to put people, so we can support more of them without either
a loss in standard of living or further depleting our ecosystem. I generally consider any scenario that allows
you to support more people without hurting the planet or reducing the standard of living
for those people to be by definition a good thing and tend to find folks who think otherwise
a bit puzzling, which is putting it politely, and we’ve talked a lot about ways to support
more people on Earth in the Arcologies and Ecumenopolises episodes. I mentioned at the time that there was a point
between those and full blown Kardashev-2 Dyson Swarms, that I generally call a Planet Cloud
or the Terran Cloud for lack of a better term. In this you are constructing rotating habitats
around Earth to make more space for people to live. These differ from a Dyson Swarm in that they’re
smaller overall in terms of living space but also far smaller and denser too. Rotating habitats are something we’ve discussed
a lot on this channel, they benefit from being able to be tailored to any climate and day
length and gravity you want, unlike other planets where it requires huge efforts to,
for instance, shorten the day or increase the gravity, and they also require way, way
less material per square kilometer of living area than a planet does. Just as an example, if we disassembled the
Moon into a bunch of 100 meter wide sheets to form cylinder habitats, the Moon would
give us about 220 billion square kilometers of those sheets, about 500 times the total
surface area of Earth and a few thousand times what we have in terms of reasonably habitable
land area. That would be about a quarter of a billion
classic O’Neill Cylinder Habitats incidentally, but there is actually more than enough room
for that many in Earth’s vicinity, places within a few light seconds where real time
communication is possible and where those would still be spaced out enough to not bump
into each other or block light from each other or Earth below. Sounds like an ambitious task, especially
if you’ve joined the channel only since the Upward Bound Series began, which is about
half the audience, but since we routinely discuss disassembling stars for fuel or moving
them and whole solar systems, or even whole galaxies, the construction of a Planet Cloud
is probably about a 3 out of 10 on the logarithmic scale of hard tasks we discuss here, with
a ten being to collapse all the galaxies within about billion light years of here into one
gravitational bound region that won’t be ripped apart by the Expanding Universe, and
doing that only with known physics and no faster-than-light travel. We like to think big on this channel. In that respect, constructing a bunch of up-sized
soda cans in orbit for folks to live on is not terribly difficult. Particularly since you can build them one
at a time, as needed, to house folks who want to have more living space while staying near
Earth. They do require a lot of mass though, even
just one fairly small version of them, would require far more material than everything
we’ve ever launched into orbit combined. Even with the systems we’ve discussed for
getting folks off Earth cheaper, none of them are really suited to moving that much mass
let alone cheaply. Not from Earth anyway, not even the Orbital
Ring which we still haven’t covered in the Upward Bound Series, but is basically the
grand-daddy of cheap transport of huge quantities of material into space. So there’s your profit source to fuel colonizing
and industrializing the Moon for purposes beyond far-distant space colonies and various
scientific efforts. You are using the Moon to mine and manufacture
all that infrastructure and living space around Earth so you can house tens or hundreds of
trillions of people in relative comfort and proximity to Earth, without needing to turn
Earth into some concrete-covered megacity, and you can do it in stages, one station at
a time. With better automation and different work
environments, it’s hard to put anything approaching a solid figure out for the kind
of workforce needed to build an O’Neill Cylinder, but I’ve calculated it a few different
ways off current market costs for materials like steel, aluminum, and titanium, and the
ballpark figure is about a million folks working for a year to provide the construction material
for one of them. We’ll assume a lot more automation involved
so that all the support industries and services needed on the Moon to build one per year would
be a million people including their kids and other dependents. If you wanted to produce a Planet Cloud in
less than geological times you’d need to be working on many of them at the same time,
maybe taking a decade each to assemble the structure and have thousands at a time you
were working on once things ramped up to full production, but under these kinds of values
we can easily have multi-million if not multi-billion person populations on the Moon. Indeed I could easily envision a trillion-person
Ecumenopolis Earth commissioning about a thousand a year to house about a billion new people
a year total, or more, and needing a roughly comparable workforce of about a billion to
build the things. Scale always gets a bit disorienting when
we start talking about even Kardashev 1 civilizations, let alone 2’s or 3’s, what we’ve discussed
here would be at least a couple centuries down the road. Early on those colonies on the Moon might
be thousand-person installations where they are working on a way more modest space station
to house a few thousand folks commissioned by, say, Brazil, to support their asteroid
mining fleet which is mostly delving for gold and platinum. Everything is done incrementally. We bring up this massive case of a multi-billion
population on the Moon to show that there is a potential large and long term industry
there not just for getting folks out to other planets and stars but directly tied to Earth’s
own normal economy. We see that industrializing the Moon can go
a lot further than a few bases helping supply fuel and raw material for principally scientific
endeavors in the next century or two. Of course to get all those colonists to the
moon, or to all those orbital habitats, we need much cheaper ways of getting folks into
space which can also be upscaled to allow transports of thousands if not millions of
people a day. We’ll discuss one such system, launch loops,
this month. After that we will be discussing predicting
the future, and the idea of Psychohistory from Isaac Asimov’s classic Foundation series. To get alerts when that and other episodes
come out, make sure to subscribe to the channel. And if you enjoyed this episode, hit the like
button and share it with others. Until next time, thanks for watching, and
have a great week!
Great as always. When do we start this?
Really changed my perspective. I was a big fan of leaving the moon for the tourists and mining the near earth asteroids.
Now I am convinced that the moon is essential.
Have to say, I haven't ever heard stories of the Moon becoming the shipyard and hab foundry of the Earth and solar system. It's really appealing to me now.