Gonna go for landing
Retro go Control go
Surgeon go We copy you down, Eagle. Houston, Tranquility Base here. THE EAGLE HAS LANDED. In previous videos weâve already leapt way
past the moon to discuss terraforming planets, colonizing other solar systems, and buildings
artificial worlds. We sort of skipped the moon because I tend
to think of it as having been covered a lot elsewhere but in truth nobody really goes
into much detail about what weâd do with the moon after getting a base there. Generally it is get there, set up base, use
base for getting to Mars somehow, and mine it somehow. We donât tend to see much actual discussion
of this base and what it does. Or how it advances the general purpose of
getting out into space or moves forward itself. I thought today weâd delve into that matter
a bit more and explore some of the options and ideas. Before we go any further, if this is the first
video on the channel youâve seen then thereâs two features you should be aware of. First, since I have a speech impediment the
videos always include a transcript and closed caption subtitles you can turn on, some people
have a harder time understanding me and thatâs not even including all the arcane technical
jargon these videos often have to include. Second, for the sake of brevity I occasionally
reference other videos on this channel or other ones where a concept got discussed in
more detail rather than repeating myself and if you see a thumbnail or video clip pop up
in a yellow or white link box you can click on that and it will just pause this video
and open that one up in a new window so you can watch that and return here where you left
off. Okay, so people often wonder why we havenât
gone back to the moon since the 70s. We did it six times successfully in a few
years nearly half a century ago and neither the United States nor anyone else has gone
there since, at least with people. In the meantime we have vastly improved a
lot of the relevant technology, especially computers and robotics which is part of the
reason. Our rockets are better, are quality controls
are better, and we can make vastly lighter or superior equipment to what we had in the
late sixties. Fact of the matter is the US could easily
do another series of moon landings and Congress is hardly afraid to cough up the cash for
that since the taxpayers would mostly not object to the expense. The European Union, Russia, China, Japan,
or frankly just about any G20 nation has the necessary technology and infrastructure to
do it. So why hasnât anyone? Of course some people doubt we ever went there
in the first place, that it was all fake, and in these modern days of photoshop and
CGI itâs hard to dissuade them. Iâve occasionally heard people suggest you
could see the Apollo Landing sites through a telescope but thatâs not true, even the
Hubble telescope lacks the resolution to view the moon and even if it did I wouldnât think
that would convince anyone since someone could mess with the video feed. We can resolve human sized objects on Earth
from space, but the moon is about a thousand times further away from us than those satellites
are. You canât see any man made objects on the
moon through any telescope we have now let alone one available commercially. So a lot of people subscribe to the Moon Hoax
theory I think mostly because they just canât imagine why we havenât gone back since and
no one else has either. But the simple reality is that as things currently
stand thereâs not much real benefit to gain from doing so. Getting some more moon rocks or drilling some
samples would certainly be nice but itâs not a particularly urgent project at the cost,
thereâs lots of other science of higher priority that can be done cheaper, and if
we did do it weâd end up using robots which would defeat the purpose. We want to stick people on the moon again
And collecting samples is honestly just an excuse to do that. So when someone inevitably points out a robot
can do it better and cheaper we end up sending neither man nor machine because we donât
really need more moon rocks. I would suspect that given a long enough time,
even without any more technological improvements, someone will get around to going there again
but for it to be more than an exercise in national inspiration you have to have some
real purpose in going there and with people, not robots. Part of the reason manned missions to Mars
are so appealing, besides being a step forward rather than a repetition of past glory, is
that the time lag to Mars is many minutes as opposed to the Moon which is only a couple
seconds. So robots can be controlled more or less in
real time on the moon. No thinking human brain actually needs to
be on the moon overseeing the affair or doing the work. To push forward with the moon we need a genuinely
valid reason to want to not just send people to the Moon, actual people not robots, we
need a reason to justify a permanent presence there. So letâs consider what the moon has that
Earth doesnât⌠and unfortunately itâs not a terribly long list. First it lacks two things which Earth does
have, an atmosphere and a gravity well. Gravity is a real downside to space travel
and the moon has much less of that, and the same is true of atmospheres. What it does have that the Earth lacks is
Helium-3. Thereâs just not much on Earth, truth be
told thereâs not much on the Moon either but it looks like thereâs way more than
we have here. This relative abundance of Helium-3 has sparked
a lot of talk about mining the moon for it, to be used in nuclear fusion. There was great film, especially considering
its low budget, called Moon back in 2009 in which such an operation was going on and of
course tons of articles in various pop sci publications in recent years. Problem being we donât have any nuclear
fusion reactors to use it for fuel in. We discussed the impact of nuclear fusion
last year and its huge, just a few kilograms of fusion fuel would produce around a billion
kilo-watt-hours of juice, a hundred million bucks worth of power, and yeah its expensive
to get to the moon and back but not that expensive, especially if youâre setting up shop and
just shooting cargo back. Moon return trips are relatively cheap since
there isnât much air or gravity to keep you from getting off the moon and plenty of
gravity to help you get back to Earth and air to slow you down on re-entry. So helium-3 mining is definitely a good reason
to go back to the moon and stay there, youâd only need to return 10 or 20 tons of the material
a year to run the US power grid. Again though, we donât have a fusion reactor,
and none of our main efforts to get fusion use Helium-3. They use deuterium and tritium, two hydrogen
isotopes, because one of the hard parts about fusion is overcoming the Coulomb Barrier,
the repulsive force between two positively charged atomic nuclei. Simply put, helium-3 consists of two protons
and a neutron, whereas tritium is one proton and two neutrons and deuterium is one proton
and neutron. Pushing a pair of protons together is hard,
like repels like, and Helium-3 has twice as many protons as deuterium and tritium so itâs
much harder. In basic terms the temperature you need to
pull off inside your reactor is about ten times hotter if you want to use Helium-3. Now a helium-3 and deuterium reaction is a
great power source but again itâs a much harder one to pull off then Deuterium-Tritium
and both of those are relatively abundant on Earth and fusion is fusion. You get any working fusion reactor and you
totally change the world. The advantage of helium-3 compared to them
is mostly that itâs an aneutronic type of fusion and that has a lot of potential advantages
especially for making a compact reactor that didnât take up whole city blocks and might
conceivably fit into a spaceship that didnât dwarf an aircraft carrier. I mentioned in that video on fusion that as
great as fusion would be it isnât necessarily usable directly for spaceships since size
and power output per mass of the reactor is very important for that application. We discussed a lot of alternatives for launch
if you have a lot of power but itâs bulky, like mass drivers and launch loops, but helium-3
reactions and aneutronic fusion reactors hold a better promise of being able to actually
cram a fusion reactor into a spaceship as a useful power source than deuterium-tritium
reactions. But even then, you also donât necessarily
need the moon as a Helium-3 source for spaceships leaving Earth. We focus on Deuterium-Tritium because itâs
an easier reaction than anything else to produce. But your ideal fusion reactor, besides one
that runs on straight vanilla hydrogen, is a deuterium-deuterium reactor, because deuterium
is very plentiful on Earth and all over the Universe. Deuterium-Deuterium requires higher temperatures
than Deuterium-Tritium but not as much as Helium-3, and a Deuterium reactor produces
tritium and helium-3 as its byproducts. If you want helium-3 you can just extract
is from the reactor, and for that matter any leftover tritium will decay into Helium-3
too. Thatâs where we get out supply of Helium-3,
we use Tritium to boost Fusion Bomb yields and with a half-life of only a dozen years
we have to suck out helium-3 and replace it with new Tritium. Though I should note that Helium-3, even if
you canât use it for fusion fuel, is still useful stuff. Helium-3 is used for quite a few applications,
these days it costs several thousand dollars a gram, hundreds of times more than gold,
so at current market prices a ton of it shipped home from the Moon would fetch several billion
dollars. Of course youâd expect the price to drop
sharply if quantity were to soar and the US supply is only about 8 kilograms a year. Sort of like how we talk about asteroids with
tons of platinum on them being worth several trillion bucks to stoke up asteroid mining
interest, the basic economics of scarcity would suggest that value would drop to a fraction
before you could sell it all. So while I donât want to say the value of
Helium-3 on the moon is overhyped itâs not really likely weâd ever be mining it from
the moon to ship home. Itâs also, again, not that abundant. Itâs not like there are puddles of Helium-3
lying around on the moon to be sucked up and shipped home. Concentrations in general would be around
1 to 10 parts per billion on the Moon to maybe as high as 50 parts per billion in areas which
are constantly in shadow. So if you want to come up with the 10 or 20
tons a year that would run the US powergrid you need to be ready to plow through at least
a billion tons of lunar regolith a year. But it has some real possibilities as interplanetary
spaceship fuel meaning the Moon could easily serve as the oil well of early and mid-stage
interplanetary travel. Thereâs way better sources of it deeper
out in the solar system. Thatâs not the only way the moon could can
be of assistance though, just a recently popular one. Weâre looking for an excuse to set up shop
on the moon permanently and in a big way, with large bases hosting dozens if not thousands
of personnel. Helium-3, even if we develop a reactor that
can use it, probably isnât that excuse unless for some reason that works out to be the only
commercially viable fusion reactor, which doesnât seem likely though there are some
serious advantages to aneutronic reactors that might make it so. Still it probably wonât be, so what other
reasons are there? Again because of the lack of air and gravity
itâs a good place to serve as a base. Itâs much easier to mine the moon, and in
some ways easier to power yourself on solar power, than it is on Earth. Low gravity makes for much easier mining and
much easier off-world transport. Lunar Regolith is very abundant in Oxygen,
Silicon, Iron, Calcium, Aluminum, and Magnesium in that order. We wouldnât ever mine those resources for
Earth itself, Earth has plenty of those, but itâs useful for building space stations
and space ships and if the infrastructure is in place the moon is a much better source
of raw materials than Earth for stuff off Earth since you donât have to lift the stuff
through miles of air and much stronger gravity. Solar power is also a pretty decent option
for the moon because it actually gets more light than Earth, as our atmosphere absorbs
and deflects a lot of what arrives from the sun. Also solar power is often problematic on Earth
because it goes away every day and clouds in the sky can make it very dim. No clouds on the moon and the day is a month
long. The moonâs circumference is just under 7000
miles, and its day just under a month, so even at the equator where the day-night terminator
moves fastest it still only moves a little under 10 miles an hour. On Earth very fast planes can outrun the sunset,
on the moon a fast jogger could, and thereâs no air resistance for vehicles and lower gravity
so if you are mining on the moon you could conceivably use solar powered robotic vehicles
that just circumnavigated the planet once a month under perpetual sunlight and returned
to their base once a month for maintenance. We generally tend to think of moon bases as
being nuclear powered, and thatâs certainly an option, or solar-powered but running on
batteries or fuel cells during the half-month of darkness but without air resistance and
with low gravity rolling bases are a possible option. Whatâs more, it isnât difficult to build
tall towers on the moon, thereâs no wind and the gravity is again very low, and the
higher you are the more light you get per lunar day because the horizon isnât blocking
your light, there are places in the polar regions like Shackleton Crater that have spots
that get sunlight 80 or 90% of the time. Since the poles are going to come up a lot
in any discussion of moon bases let me explain that a bit more. We all know about the midnight sun and how
places near our own poles here on Earth have months of perpetual darkness or sunshine. We also mention polar bases on the moon a
lot and places where the sun shines longer. There are places on the poles of the moon
where we expect to find more ice, the poles are colder, and ice is good because we need
water. There are places on the poles that get light
longer, or darkness longer, than near the equator too. This isnât for quite the same reason as
it is on Earth. On Earth, the Earthâs Axial Tilt relative
to the Sun means that higher latitudes are constantly facing the sun for months at a
time or faced away from the sun for months at a time. The moon on the other hand has very little
tilt relative to the sun. This isnât the cause of the places with
long light or dark phases. There is a concept called the Peak of Eternal
Light where a spot on a rotating object around a star might be lit all the time, or nearly
all the time, not to be confused with tidally locked planets like we discussed some months
back. On those the sun shines on one half of the
planet all the time and never on the other. As we also discussed then, there is no âdark
side of the moonâ, because the moon is tidally locked to Earth, not the Sun. One Moon Day and one Moon year are the same
length, one Earth month long. But there are places on the moon where the
sun shines 80% or 90% of the time. And the cause isnât axial tilt or orbital
patterns, itâs that the moon is much smaller than Earth, with a much nearer horizon, and
that thereâs no winds or tides eroding all the craters on the moon. A mile high mountain on the moon juts out
much more than one on the Earth, and the higher you are, the longer your day. Here on Earth if you climb up to the top of
a very tall building or hill or mountain and your friend stays down on the ground next
to you, you can see the horizon further off than he can. So you see the sun rise before he does, you
see the sun set after he does, your daylight period lasts longer. Weâll take this simple globe and add a peak. Watch as the day-night terminator sweeps around
and hits the high point first, and then as is sets how the high point remains illuminated
longer. The higher the peak, the further it is to
the horizon in each direction. This more pronounced on the Moon because the
Moonâs diameter is considerably smaller than Earthâs so a mile high object sticks
out more. Similarly if you were in a valley the sun
would rise later and set sooner. If you were on a mountain peak that had two
large valleys to the east and west located where your horizon would be if it was flat
there instead the sun will rise even earlier and set even later. Same concept, if youâre in a valley with
a mountain to the east and west the sun rises way later and the sets way sooner. So if youâre in a deep crater on the moon
with large crater walls you wonât see much light, even less than on Earth since thereâs
no atmosphere scattering and reflecting light from other directions. This effect gets even more pronounced near
the poles because the planetâs âdiameterâ, at least in terms of the distance from the
axis of rotation, is even smaller and thatâs what is actually blocking the light. Watch as these identical mountains at the
same longitude but different latitudes have the day-night terminator run over them. See how the sunlight leaves the ones near
the equator first? So we often have an interest in polar bases
on the moon because theyâve got spots in them that get sunlight much longer, and often
very close to places that get shadow much longer. Places on the poles which are under almost
constant shadow are way better spots to find ice, also where youâd expect to find more
Helium-3 for that matter. So a polar base located in a large crater
is a nice base location since youâve got some optimal places to put solar panels that
can run most of the time and right nearby youâll have dark spots where youâd expect
to find more water ice. Also again, because gravity is so weak and
thereâs no wind, you can build incredibly tall flimsy towers that further extend your
daylight, with solar panels or even just mirrors on top of them. Youâd still need batteries or fuel cells
but for a much shorter period of time. You could also get around this long night
issue by using power satellites that beamed their energy down to a base. Satellites consisting of basically just a
reflective parabolic dish and some attitude controls constructed on-site would be fairly
easy to launch, as weâll discuss in a bit, and could keep an area pretty well lit perpetually,
or send it down as a power laser or maser to some receiver. For that matter the moon isnât that big
and itâs desolate, so you could just outright run power cords along the surface, or build
a few solar towers that beamed energy to other towers not in the sun. Towers can get very tall on the moon because
thereâs just no wind and weaker gravity puts less compression on the materials. But thatâs also not the only way to build
a very tall tower, you can rely on tensile strength instead of its tall enough, thatâs
the basic concept of a space elevator. As we discussed in the Megastructures video
on Space Elevators while we donât have any material strong enough that we can mass produce
to make a space elevator of earth we do have that option for the moon. A lunar space elevator is a bit of an oddball
because it has to be longer than an Earth Space Elevator and can only point in two directions
to be stable since the Earth perturbs lunar orbits much more than the moon disturbs Earth
orbits. The first stable one would point right back
at Earth, and the second directly away from Earth, but thatâs fine. The one pointing at Earth needs to be 35,000
miles long and the one pointing away from Earth would need to be just over 40,000 miles
long to the their respective docking ports, as opposed to a space Elevator on Earth which
would be just 22,000 miles long. This is because the moon, while it has weaker
gravity, also spins much slower. The one on Mars is much shorter because its
day is about the same as Earthâs own but its gravity is a lot weaker. But the Moonâs gravity is so weak that you
donât need any ultrahard materials to build it from. Same as you can build towers on the moon very
tall without much wind or gravity to impede you, we can build a space elevator on the
moon much more easily than on Earth which makes it even better for mining to fuel space
industries in the general area of Earth. But every space elevator needs a counterweight
on the end of it, we usually picture this as some asteroid towed in for that purpose
or some very large docking facility, on the moon that could be a bunch of mirrors in whole
or part and not only are the tops of space elevators virtually always in the sun but
even for the short time one lunar elevator wouldnât be, the one on the other side of
the moon would be and you could just bounce that light down to a base from the mirrors
or beam it down as power. And you could target anywhere on the same
hemisphere so with two elevators you could illuminate any place on the moon. Lunar space elevators are a pretty neat idea
and the added power and light advantage makes them even more appealing but ground based
solar and batteries or fuel cells, or just having a nuclear power plant, is probably
more practical. Also while elevators are far easier to build
on the moon they arenât nearly as handy as they would be on Earth. We discussed mass drivers, space cannons,
and launch loops a while back and the big issue using those on Earth to launch vehicles
is you have to make the track very long to get up to the necessary speed to escape Earth
while having a low enough acceleration to not crush human passengers. This is made much more impractical because
youâve got to keep the tunnel evacuated of air and getting the muzzle of the space
cannon out over the atmosphere. Thatâs not even an issue on the moon. Thereâs no air, and the escape velocity
of the moon is just over a fifth of what it is on Earthâs, meaning you only need about
4 or 5% of the energy and your track can be much, much shorter and you donât need to
elevate the end of the cannon over the atmosphere because there isnât one. To get up to Earthâs escape velocity at
just one gravity of acceleration requires almost twenty minutes of acceleration down
a 4000 mile long track ending on towers many times higher than our tallest skyscrapers
and the whole thing has to be a sturdy vacuum sealed tunnel. To get up to the moonâs escape velocity
at one gee of acceleration wouldnât require even 200 miles of track and it could just
be track, like a normal railroad. Even though building giant towers on the moon
is way easier than on Earth you donât need them, thereâs no air to flood your tunnel
or cause drag or lift. Also track length drops proportional to acceleration
so if you donât mind subjecting people to, say, 4 gees of acceleration for just over
a minute your track only needs to be fifty miles long, and if youâre just shooting
raw materials or fairly sturdy manufactured items up than you can get away with a hundred
gees easy and have a track just 2 miles long, truth be told raw materials like iron could
be shot out at 10,000 gees or more easy, thatâs the acceleration inside a rifle, and that
would only need to be a hundred feet long. So we might not build a lunar space elevator
even though we could just because using space cannons is so practical and way easier to
shield from micrometeors and solar radiation, which are serious issues on the moon. You could launch stuff directly to Mars from
there. Youâd still need rocket fuel, but way less
of it, and you can refine fuel on the moon. As noted earlier, lunar regolith contains
huge quantities of oxygen, aluminum, and magnesium. Liquid oxygen burned with aluminum or magnesium
is a pretty decent rocket fuel, and monopropellant gel of aluminum powder and liquid oxygen appears
to be very promising too. We talked in the terraforming video about
baking oxygen from rocks, but in summary form you could make from locally available materials
whole acres of solar ovens and still for creating this fuel, which could also be used to help
power a moon base during dark phases as well. Ships could leave the Moon for places like
Mars or Asteroids via a mass driver boost and fully fueled up to speed up more and to
then slow down. Or you could ship that fuel elsewhere. Truth be told, once the infrastructure is
in place, it might make more sense to ship fuel from the moon to earth orbiting space
stations refueling ships that left Earth Orbit then to ship up more fuel from Earth itself. It would really depend on how easy such fuel
refineries were to build and maintain, and with the progress weâve been making in robotics
and 3D printing that might be very easy indeed. We do want to put people on the moon, but
robots are almost certainly going to play a huge role regardless especially in early
construction phases. Things would be a lot easier and safer, not
to mention cheaper, if your initial moon base is constructed before the astronauts arrive
by drones. Which brings us to our next point. The classic moon base tends to show up with
a lot of glass domes but this isnât a really good idea. People donât particularly need direct sunlight,
particular raw sunlight that hasnât had the nastier stuff filtered out of it by out
magnetosphere and atmosphere, and our plants wouldnât do great under that light either. Glass is a poor protection from micrometeors
too. So you wouldnât be building your structures
above ground, or if you did you come by and plow over them with dirt afterwards. A couple feet of lunar regolith between you
and space is an ample shield against anything you really need to worry about and because
of the lower gravity the structure doesnât need to be too sturdy to handle that weight. If you need to get light in you can have glass
walls and have your roof extend well over it, then just have mirrors bounce the light
in. Those can be made to not reflect the harmful
frequencies rather easily and mirrors donât have to be made of material that shatters
when it gets hit. So even your food crops wouldnât be exposed
to the open sky and your actual habitation areas would probably be as deep underground
as you could comfortably get away with. Iâve also mentioned before, in both the
terraforming video and rotating habitats video that while we can fake gravity with rotating
structures in zero gravity, you can do this in lower gravity too. You have to combine the natural gravity with
the spin gravity so that inside that structure your perceived down is at a diagonal. Thereâs no air outside for drag so it wonât
take much energy to keep such a thing spinning. This keeps your moon men from suffering the
ill effects of lower gravity, which is very detrimental to the body over long periods
of time. Now again everything is easier if youâve
got working fusion, which you obviously would if you were mining the moon for helium-3,
but setting up shop on the moon without fusion is definitely doable. It hasnât been done thus far because itâs
very expensive and doesnât serve much point. It also the sort of thing where you need to
go all-in, a small moon base manned by a dozen people like some polar research station isnât
the way to go, even if virtually everything is being run by robots. The moon is not Mars, signal lag time is only
a couple seconds, so even maintenance on robots could be conducted by other robots controlled
mostly real time from Earth. You donât need a moon base for a Mars Landing,
but if youâre hoping to truck thousands of colonists to Mars and have routine traffic
and supplies going back and forth it makes that way easier to have the moon either directly
in that loop or sending fuel to stops in that journey. And if you want to do anything serious on
Mars you do need to send people, the time lag is just way too high for practical remote
control. So any serious operation on Mars or any other
location deeper out benefits from having a lunar base feeding in fuel and material to
the travel loop. You donât need people on the moon to do
anything if youâve got good enough robots, and I mean mechanically good enough not smart
enough. You could control the entire operation from
Earth. But if you want people there you need a decent
number because youâre setting up a community. Youâre growing food, cooking food, building
habitats, repairing your robots, conducting experiments and so on. McMurdo in Antartica is probably your better
example, even in the winters thereâs about 250 people there and a few times that in the
summers. We mentioned Dunbarâs number, around 150
or 160 people, during the interstellar colonization video and as a quick reminder thatâs generally
considered a good size for a community. You could get away with less than that though
since it is only a couple seconds to the moon so while chatting on the phone with relatives
would be a bit laggy, taking 4 or 5 seconds for you to hear their reply to âGood morning
how are you?â, itâs still takes a lot of the psychological pressures off people
in terms of those we encounter from remote outpost with small numbers. There a going to be things where that signal
lag is too much, like performing surgery on someone who is injured, and thereâs a lot
of types of maintenance that at best would be a major hassle to do with a robot drone
and a 4 second delay. Of course if youâve got people up there
you need to feed them, so you also have to grow all your own food, it costs tens of thousands
of dollars in fuel to ship just one dayâs worth of rations into low orbit and the moon
is much more expensive, so keeping a hundred people fed on the moon perpetually would be
running you billions of dollars, plus the vegetation can help recycle your air and water
and waste. This raises the sunlight issue again, because
the day last a month on the moon, meaning that except near the poles youâve got to
cope with two weeks of darkness. Even if your plants could handle two weeks
of darkness they arenât scrubbing carbon dioxide out of the air while youâre doing
that. The two weeks of constant light is no big
deal, if youâre pumping your light in via mirrors or fiber optics you just block that
or tilt it away as necessary. Many plants do fine, even better, under longer
light cycles, though others do not and many use it to trigger flowering so light control
is a big deal if manageable. Darkness is another issue. You can get around that at some spots on the
poles. Plants can handle a few days of low or no
light by and large and you could run some lights off batteries or fuel cells or even
rocket fuel if youâre mass producing that during light periods. Truth be told youâd probably be wanting
to run those backup lights during the day a lot too, when power is abundant, since you
can boost plant growth by pumping up the wavelengths of light that are used for photosynthesis
and that lets you use less mirrors and you can build your farm a bit more vertically
then. Which is doubly handy if you want to have
higher gravity in your farms than the Moonâs actually got. Another nice thing about the moon is that
with those long dark phases, low gravity, and no air it a pretty handy place to build
telescopes, especially the new liquid mirror telescopes which could be made obscenely large. The basic concept of a liquid mirror is like
our combined natural and spin gravity. When you spin a liquid on earth it forms a
parabola from the mixture of gravity and centrifugal force, a natural parabolic dish you can shape
by adjusting the spin rate of the device. We use mercury on Earth for this which isnât
ideal for the Moon but weâve also been having some good progress with a class of organic
compounds known as ionic salts that should function in that role on the moon and actually
look like it might be cheaper to build on the moon than here on Earth and thereâs
no air or light pollution making it even better as a location. Thereâs one last object that can be built
on the moon, and can arguably only be built on the so-called dark side of our moon and
thatâs a giant laser. We talked about using lasers for pushing ships
to very high speeds and youâre probably also familiar with the idea of using laser
to blow up or divert asteroids that might threaten Earth. The problem with big lasers is they are big
weapons and the dark side of the moon is called that because it never faces Earth. If thereâs one place in the Solar System
you could feel fairly safe about building a giant laser that couldnât be used as a
death ray against our own cities, thatâs the spot. Also when dealing with doomsday weapons if
you actually run the numbers on the kind of energy the things use unless youâve got
special scifi unobtainium to get rid of the heat the entire thing ought to melt. You can only get rid of heat by radiation
in space, so if you build it into an object like the moon you not only get all that rock
to use as armor to protect critical components but you can also shunt all that heat into
the moon by convection and conduction instead. That way you donât have to big thermal exhaust
ports your rebellious son can shoot torpedoes down and blow up your massively expensive
doomsday device. The picture that gets painted here though
is that a return trip to the moon really doesnât serve much point unless you plan to set up
permanent shop there in a fairly big way, and weâre unlikely to want to do that until
weâre ready to seriously push out into the solar system in which case the moon has the
potential to be an invaluable resource. Weâre not ready yet, and it can be kind
of depressing to think that itâs been almost half a century since we last set foot on it. But keep in mind that while Antarctica was
first explored in the early 1800s, the first expeditions to get to the south pole took
place decades later in the early 1900s and it was 1911 before Amundsenâs team got to
the South Pole, narrowing beating the ill-fated Terra Nova expedition led by Robert Scott
that arrived a month later in January of 1912. It was 45 years before anyone returned, and
the US Navy flew in and established the Amunsden-Scott Station there, about the same time as it has
been the last moon landings and the production of this video. Even then this facility wasnât a major installation
until more recent times, being completely rebuilt in the mid-1970s. Now, just over a century after those first
two expeditions to reach the pole, it is a thriving and productive research facility
manned by a few dozen in the winters and a hundred fifty in the summer, and is one of
many such facilities in the Antarctic and Arctic. Good things take time, and just because you
can do something doesnât mean you should. Our base on the south pole is robust now because
itâs useful, itâs vital for astrophysical and particle research. Whether a moon base comes about because helium-3
becomes valuable as a fusion fuel, or because we want to use the moon to get raw materials
and fuel for projects around Earth or deeper in space, or as a lifeline to Mars and other
planets and asteroids, or to build truly enormous telescopes on, or just from sheer human drive
and human stubbornness to do it, or some combination of all those, it will happen eventually. So on that note weâll close out for today. If you enjoyed the video please like and share
it and subscribe to the channel, and feel free to try out some of the other videos on
the channel. As always question and comments are welcome
below, I try to reply to as many as I can and Iâm always looking for new video ideas,
this video itself came from a request just a few days back when I was having a bit of
creative writerâs block for instance. Thanks for watching and weâll see you next
time.
The first 11 minutes or so of this video are mainly talking about Helium 3 and why it isn't all that good a reason to establish moon bases (at least not by itself), so if you want to get straight to the reasons why a moon base is a good idea and what sorts of bases we might build I'd advise skipping to the 11 minute mark.