After over half a century, it is time to return
to the Moon, and use its vast resources as a bridge to countless new worlds. Welcome to Science & Futurism with Isaac Arthur,
and I am your aforementioned host, Isaac Arthur, writer and producer of this show and also
President of the National Space Society, an organization dedicated to a future of space
settlement. And when it comes to settling space, finding
a way to set up self-supporting bases on the Moon is necessarily always at the forefront
of those efforts. After all, if we canāt make things work
on the Moon, the only celestial body within real-time communication distance of Earth,
how could we ever hope to make things work on any other planet? At its core though, the Moon is not just the
prototype place to try out space settlement, but also the gateway to those other places
because it is very rich in resources to mine, process, and refine, but also low in gravity
and air, the two things that make getting off Earth and into space so hard. This is why we have done many episodes on
the Moon, and will doubtlessly do many more, and why today we will be focusing on how we
get those resources; and in the near future, with existing technologies. And it all comes down to economics and the
tyranny of the rocket equation. If I want to put a spaceship on another planet,
I either need a vastly better fuel and propellant, or I need to be willing to launch dozens of
ships into space carrying a payload of fuel, just to be able to have the fuel to send one
of those spaceships off to another planet. That ship isnāt moving too fast either. Even if a better fuel is found, it is still
better sourced on the moon, but so is all that air, water and honestly anything that
we can build there instead of here on Earth. That might get sophisticated as we improve
automation and options like 3D printing. For now though, itās okay if we have to
fly every sophisticated piece of equipment up from Earth, every microchip or control
panel, if we can produce big, thick shielding panels for the ship, or water tanks, or the
water for those tanks, on the Moon. Or simply get the resources there and move
them to orbital factories and dockyards near Earth. After all, on the Moon, we have a power generation
issue. Thereās no fossil fuel or wind or hydropower,
but there is half a month of sunlight followed by half a month of darkness, which makes solar
kind of viable, and there are plenty of options for using nuclear reactors there as thereās
not much worry about radiation. Or rather, the place is already pretty irradiated
so itās not a big concern to add to that. We could contemplate some sort of arrangement
where nuclear combined with solar ran a lot of power-intensive projects at a base for
two weeks, then shifted to lower-power ones. Maybe you smelt metal for two weeks and then
spend the next two weeks surveying for, or collecting, new ore. We do have a lot of ways to supply power in
the dark period too, and for that matter there are places on the Moon that are more or less
dark than the average. Some crater bottoms are perpetually dark,
or nearly so, and lava tubes too, whereas some crater rim walls, especially far from
the equator, get much longer periods of light. Those craters and lava tubes are of immense
interest to us as resources sites too. Now, when we talk about building a lunar economy
up and extracting material from there, itās worth noting that this is not pie in the sky. Carisa Christensen, CEO of Brycetech, says
the annual investment in the lunar economy is currently around 10 billion dollars a year. This is principally government funding, and
Project Artemis is around 7 billion of that. But it means we are, and have been, putting
billions into R&D focused on the Moon. And by we, that does include both private
sector spending and other governments, the Canadian Space Agency (CSA) and Japan Aerospace
Exploration Agency (JAXA) are both big partners on Artemis. Incidentally, for the raw facts and figures,
Iāll be drawing heavily today on John F. Krossās 2022 Ad Astra Article, āThe Lunar
Economyā, as this episode is intended to be how we get stuff off the moon economically
this century, not in the more distant future. So while we might one day mine Helium-3 off
the Moon for aneutronic fusion reactors, for today weāre assuming we donāt have any
new power generation technology beyond minor modifications to adapt stuff we already have
to be functional on the Moon. Same for other technologies, it need not be
something we have streamlined or achieved mass production of or even built an official
prototype, but it does need to be solid tech. That said, a little later in the episode,
we will dip a bit into harder lifts like a Lunar Mass Driver for getting cargo off the
surface. That technology is pretty solid but it does
still have some hurdles to clear and more to the point, it represents a pretty big piece
of infrastructure, and our other limitation today is that weāre not really contemplating
megaprojects. Our biggest limitation on getting to space,
and then getting to the Moon from there, and finally getting things off the moon, is fuel,
and the majority of the weight of the fuel isnāt actually the fuel itself but the oxidizer
we burn with it, which is typically oxygen. The downside of rockets is they canāt be
air-breathing because thereās no air off Earth and even making an air-breathing rocket
for use during travel through the atmosphere is often considered impractical. Though designs like SABRE for the Skylon spaceplane
seek to make it otherwise. Whether or not they succeed in that effort,
it doesnāt help once youāre in space or on the moon because you need that oxidizer
and it is literally the supermajority of that shipās mass, out-massing every drop of fuel,
piece of ship, and item of cargo combined. Oxygen is heavy, and our two major rocket
fuels are liquid hydrogen and kerosene, both of which combine with oxygen molecules to
make water, or water and carbon dioxide. A water molecule, H2O, may be two to one hydrogen
to oxygen atoms, but that single oxygen atom is 16 times more massive than hydrogen atoms;
and water is 89% oxygen by mass, while carbon dioxide is 73% oxygen by mass. So, even just being able to produce our oxygen
on the Moon would let us save massively on the return fuel for any lunar trip, or for
shipping anything off the moon for orbital construction. We also need oxygen to breathe, and so looking
at how we can get oxygen on the Moon will be our first topic. And the first step of that is finding oxygen,
but amusingly thatās the super-easy part. For a place where there is no air we tend
to think of getting oxygen as hard, but oxygen is the third most abundant element in the
Universe and the most abundant element on the Moon. 42% of the Moonās mass is oxygen, tied up
in rocks like silica, SiO2, AKA quartz, much as on Earth, where oxygen is the most abundant
element in our crust and the second most abundant overall, shortly after iron, of which there
is a vast quantity of in our core. So, finding oxygen on the moon is easy, you
literally canāt walk there without tripping over the stuff. Getting it out of the rock is trickier though. This is a lot of the reason why hidden deposits
of ice in craters or lava tubes is very interesting to us in exploring the Moon, as it takes considerably
less energy to get oxygen out of water or ice than out of rocks like Silica or Alumina,
which includes sapphires and rubies, or Lime, which you might have had to clean out of your
bathtub if you have hard water. Plus, the process also frees up that hydrogen
in the water. You can then burn that hydrogen and oxygen
right back together into water as a rocket propellant. This is a very simple process but takes more
energy to separate it than recombining it is going to get you, which is why we donāt
just burn water as a fuel on Earth, but itās a good way to make an energy-rich portable
fuel ā for rockets or for rovers or smaller satellite facilities, if you have a big, bulky
stationary power source, like a nuclear reactor, or several acres of parabolic mirrors focused
on a solar thermal tower that could produce tons of fuel and oxidizer during those two
sunny weeks and then lie dormant thereafter, till the sun rose again, letting you produce
a ton of fuel and oxidizer in the meantime, at a rate of about 13 million joules per liter
or kilogram of water to be separated, though probably a decent chunk of that would be lost
to various conversions and inefficiencies. In the absence of readily available water
though, we have an alternative to electrolysis, and thatās metalysis or cracking rock, which
is generally about 45% oxygen by mass on the Moon. This takes a lot more energy, varying by the
rock type, and instead of getting oxygen and hydrogen, what you usually get is some metal
plus oxygen. Which is a plus too, as we want to be able
to mass produce steel or aluminum or titanium or silicon there, not just air. There is a million dollar prize from NASA
for the first team to demonstrate a method to extract five kilograms of oxygen from simulated
moon rock in eight hours or less, which works out to 15 kilograms or 33 pounds a day. That might not sound like much, and indeed
isnāt for fuel, but it's all the oxygen you need for several humans to breathe during
that time. We go through a little under a kilogram a
day per person, 0.84 kilograms or 1.85 pounds, on the space station and presumably the consumption
would be similar on the Moon. Around 15 years back, Derek Fray of Cambridge
had put together a reactor that could do about a kilogram of oxygen for 142 megajoules, which
is an order of magnitude higher than electrolysis of water but was producing metals as well,
and that would work basically anywhere, on or of the moon, on some asteroid. For context though, a rocket booster might
easily go through hundreds of thousands of kilograms of oxygen to get off Earth, and
tens of thousands to get off the Moon. So if I wanted to get ten thousand kilograms
or ten tons of oxidizer produced every day, during a day cycle on the Moon, we are talking
over a trillion joules of energy, or 16 megawatts, to produce about 7 kilograms or 15 pounds
of air per minute. Enough for a 80-person team to breathe for
a whole day, produced in one minute, or enough for a modest daily launch of a roughly equal
weight of cargo off the moon. Meaning you could be running a depot somewhere
producing refined metals that are launching using the oxygen released during the making
of those metals. 16 Megawatts is both a lot and not much, a
couple months back we looked at various small modular reactors for nuclear energy and the
smallest module we discussed there was a 20 megawatt design by Last Energy. On the solar front, there is no air in the
way on the Moon, so a whole bunch of shiny aluminum parabolic dishes pointed at a solar
thermal tower should have no problem providing at least 100 watts per square meter of actual
electricity, and a good deal more in terms of heat that might be used to assist processes
for separating rock. So a field 70 meters in radius should do the
trick. One of those alternate oxygen-creation methods
is to heat rock to above 900 Celsius, and many metal-forging processes are heat-dependent,
so energy being lost to heat in the usual flow of making electricity can at least be
partially productively repurposed. We also have magma electrolysis, where you
melt lunar regolith by running electric current with it, liberating oxygen at temperatures
of 1400 degrees Celsius or 2500 Fahrenheit. Given that making big shiny metal panels shaped
as parabolic dishes out of native aluminum is not that hard of a process, one could imagine
landing with some pre-built ones or a reactor, and using that power to build more, in situ
bootstrapping of energy. As a minor sidenote, during the daytime on
the Earth-side of the Moon, it is usually night time on part of the planet, so power
creation on the moon, without air to interfere, could plausibly beam energy back to either
Earth itself, during Earthās night phase, when Earth-based solar doesnāt work, or
to various satellites and facilities in orbit of Earth but currently in its shadow. Every little thing that might make money on
the Moon or decreases losses on surplus production is one more thing that makes lunar settlement
viable. This is definitely a thing of the next couple
of decades too. Citigroup analysts are expecting the annual
revenue of the space industry to hit a trillion dollars by 2040, which isnāt that far off
anymore, and theyāre predicting a 95% reduction in launch costs by then. This is not assuming any new technologies,
just anticipated ones making expected progress at streamlining and improving, paying off
the research costs and scaling the production of the technology up. One of the notions suggested for scaling up
fuel production on the moon would be setting a guaranteed price for a time, several hundred
dollars a kilogram, and at that point in time someone can rely on a decade of steady revenue,
which makes it feel less risky of an investment. But if we imagined a single parabolic dish
or photoelectric solar panel around a meter across that was steadily producing 100 watts
on average for a decade, then under electrolysis we would be able to produce over 2000 kilograms
of rocket fuel by electrolysis or 2-300 kilograms of oxygen and a similar amount of metal. If youāre expecting to make several hundred
dollars on each of those kilograms, then youāre looking at somewhere around a hundred thousand
dollar return off that single panel or dish. Such a panel might only mass a kilogram, or
even less, especially first generation ones brought from Earth, which might then get to
the Moon for under a thousand bucks a piece and recoup that investment in a month or two. I should also note that our options arenāt
just electrolysis of water or metalysis or cracking of rocks. We also have some carbon dioxide on the Moon
and we are getting pretty skilled at separating carbon from oxygen. Carbon is quite valuable too, and needless
to say carbon dioxide is handy for plant growth on the Moon, which would reduce food you need
to bring in. As another minor sidenote, since gravity is
small on the moon and there is no air or wind, your panels and dishes can be large with relatively
little structural support. Your big issue is cleaning dust off if it
gets on there, which would mostly be from astronauts walking around or from rovers milling
about to do errands. You can potentially be sticking 10-meter-wide
panels atop telephone poles, tall, but skinny supports. And given the low gravity, itās not that
much work if someone needs to climb a ladder to one either. One critical thing to building anything on
the moon is that every bit of structural support can be vastly weaker and thus lower in mass
and all of these factors reduce the cost. The exception to that is storage tanks, since
any vessel under pressure on the moon actually needs to be a bit tougher than on Earth, where
we at least have one atmosphere of pressure pushing back already. And this is one reason why molten salt techniques
for generating and storing energy are nice on the moon, as molten salt is not under any
pressure, and thus doesnāt need to be sturdy like a steam engine or turbine on the Moon
would still need to be. Molten salt approaches also potentially allow
oxygen production as a byproduct. So, using molten metals to produce air and
generate and store heat is attractive on the moon, where insulation is easier anyway, and
this might be getting energy by nuclear or by solar thermal farm or solar photovoltaic. And possibly a mix thereof. Running power cords on the Moon between facilities
isnāt terribly tricky either, nor is avoiding the dark cycle by just having some power-beaming
satellites orbiting the Moon, and given that space-based power production might be one
of the big industries of the Moon, they may have relatively cheap access to it. Solar thermal and nuclear are both attractive
options on the moon, but silicon photovoltaic cells remain a strong option there too. Blue Origin has been working on Blue Alchemist,
their solar panel design made from lunar regolith simulants. Their reactor produces iron, silicon, and
aluminum through molten regolith electrolysis, running current through the regolith, and
produces oxygen as a byproduct, with silicon thatās been purified to 99.999%, and they
have now made working solar cells from this simulated regolith. The process they developed may have applications
back home too, as itās entirely electricity-based and appears to be much more environmentally
cleaner than currently employed methods for getting silicon. Thereās a lot of silicon on the moon too,
silica or silicon dioxide is the most common compound on the moonās surface, at nearly
half, followed by alumina, di-aluminum trioxide, at around a fifth to a quarter, and then a
rough three way tie between lime, which is calcium oxide, Iron Oxide, and magnesia, or
magnesium oxide, each making up a tenth or so of lunar surface compound, depending on
region. Titanium dioxide comes in at a few percent,
and sodium dioxide at a bit under a percent, and everything else at far lower concentrations. But that means from a practical standpoint
we have an unlimited supply of Oxygen, Silicon, Aluminum, Iron, Magnesium, Titanium, and Sodium. Note that hydrogen, carbon, nitrogen, potassium,
and phosphorus, all fairly critical to life and farming on the Moon, arenāt casually
abundant and may be easier to truck in initially. We donāt have to get everything in situ. If you can get 90% of your raw mass on the
moon instead of Earth, that massively alters the space economy. For one thing, it also creates one, since
youād have all that industry and freight capacity to and from the Moon that would make
other industrial and economic sectors easier to start and piggyback off of. It is important to keep in mind that we really
donāt know the best way to get resources off the Moon yet, other than that, many techniques
from Earth probably still apply well while other crazy options might work too that would
never work on Earth. For instance you might use a roving mining
facility that trundled around to good small deposits then basically went over top them,
suction-cupped over them, then blew out huge inflatable mirrors the size of football stadiums
to act as a solar oven on that spot, vacuum up the superheated gas and centrifuging it
into its constituent bits. Such a tactic would be utterly insane on Earth,
and probably isnāt the most efficient approach on the Moon either, but even so, it would
actually work. I would say your processor might just be a
vacuum cleaner rolling around the moonās surface but vacuums donāt work on airless
planets, so just a scoop would have to do. That low gravity and lack of air also make
it fairly easy to move cargo around, so we neednāt really contemplate onboard refining. Rather, we can expect surveying drones to
wander around looking for the best deposits of the desired material and then for something
bigger to come on by and get it, probably by either that scoop, or a sweep approach,
maybe by an actual robot, hand-picking up loose rocks of a desired material. This might not be on the Moonās main surface
either. Those craters in many cases are going to have
some nugget of some meteor in them which might be a nice individual find, and those immense
lava tubes might be great places to mine too. I donāt want to give the impression that
our options are limited to just dumping energy into rocks to melt them down. I like that one as a general one-size-fits-all
approach thatās easy to explain to folks new to the topic but in all probability itās
one that will rarely get used. It is essentially the brute-force energy approach,
which is mostly handy for its simplicity. Also, it may be needed in some cases simply
from restrictions. I am strongly of the opinion that the Outer
Space Treaty can be ignored as a placeholder awaiting something more informed and useful,
but it is entirely possible it or some future modification or successor of it might see
restrictions on resource utilization. We might see a ban on fission reactors there
or power beaming from there or limits on mining techniques that involved throwing lots of
high speed dust or releasing certain vaporized materials or quantities thereof. I think your two biggest non-fuel demands
are going to be steel and aluminum, truthfully we donāt need much oxygen to breathe and
much would be recycled by growing some supplementary plants and herbs for fresh greens and flavor. Aluminum is abundant but the preferred source
is assumed to be anorthite, one calcium atom, 2 aluminum, 2 silicon, and 8 oxygen, and would
typically be obtained by grinding anorthite out of anorthosite, and then magnetically
separated from magnetic anorthite. The FCC Cambridge Process is a favored process,
using electrolysis of the ground up anorthite in a bath of molten calcium. After the oxygen comes out and the calcium
melts into the bath, we would expect the silicon to remain solid and the aluminum, being denser
than calcium chloride, would drip out the bottom for collection. The process would probably need fine-tuning
for a lower gravity environment. It would anticipate yielding, 46% oxygen,
20% Silicon, 19% Aluminum, and 14% calcium by mass. A parallel approach works for removing Iron
and Titanium from Ilmenite, found plentifully in the Lunar Maria and is magnetically separable,
and gets you 37% Iron, with the balance of the mass equally split between titanium and
oxygen. There are other ways to get Aluminum out too,
like raising it to 2000 Celsius in a vacuum, and again; any of these materials can be taken
down to the atomic level with sufficient application of energy. The trick for optimal processing is finding
that goldilocks spot of effort, time, equipment, and energy, and that will be different for
every material, but an abundance of sunlight, lower gravity, and lack of air are the three
critical factors, likely to shift which processes work best on the Moon as opposed to Earth. Also, here on Earth we have vast supplies
of water as a coolant or solvent, and a surplus of manpower and replacement components. Stuff built on the moon needs us to contemplate
cooling options beside air or water, and must be very durable and potentially need replacement
components that can be easily 3D printed. Remote control and maintenance options are
also viable on the Moon, as itās close enough that signals lag on a couple seconds, not
minutes or hours as with the rest of the solar system. Also while we talk about it as a great place
to get oxygen or aluminum off of, valuable elements like gold or platinum are every bit
as plentiful on the moon as asteroids. Speaking of Aluminum again though, while it
is a high-energy cost material to make, it is a handy one for production on the moon
for many reasons, but maybe most of all, early on as an alternative to water. Hydrogen and hydrocarbons arenāt the only
things that burn when combined with oxygen, and aluminum is a great example of that. Aluminum will burn with water, to produce
alumina and hydrogen molecules, and vice versa, you can use hydrogen molecules to take alumina
and turn it into aluminum and water. This fuel is called ALICE, short for Aluminum
Ice Rocket, and is likely to be a great in situ fuel any place where ice and rock are
both plentiful, like the outer asteroid belt, or moons of Jupiter and Saturn. But if the moon turns out to be a hard place
to get water or hydrogen from, we can combine iron oxide and elemental aluminum to instead
produce aluminum oxide and elemental iron, and release a lot of energy in the process. This is also known as thermite, and is already
used in some rocket thrusters. Producing thermite on the Moon and processing
it into rocket fuel is a relatively simple process, and I like it as an option not because
itās any sort of miracle fuel, but because the stuff is going to be plentiful any place
you land, even places where no in-situ water is a stark reality. And itās not just aluminum either; boron,
chromium, magnesium, silicon, titanium, zinc and others all have pyrotechnic combinations
with some sort of oxidizer, which isnāt just molecular oxygen but a number of common
oxides. So if the Moon is where weāre getting a
lot of our fuel and raw materials for expansion out into the solar system, using fuel systems
that can be refilled at the destinations or waypoints is a good plan. Carrying return trip fuel with you is beyond
brutal, again the Tyranny of the Rocket Equation, and likely to suck any profit or practicality
out of any venture needing to bring stuff home in quantity. Amusingly your rocket exhaust is partially
vaporized metal so itās not a horrible idea to contemplate shooting things out of a long
tube or tower, like a gun barrel, where your metallic and oxide exhausts can be partially
reclaimed. Again, thereās no air on the moon so even
some lavatube shaft repurposed and shored up to serve as a long runway is a possible
option. This would still apply to water or an alternative
fuel like methane, and I think we hear these options discussed more because they are a
lot easier to make and use, and we have grown increasingly optimistic about getting water
on the Moon. Long term, the Moon hasnāt got much water
or hydrogen, so itās not a good source for it for ages to come, but itās a good boon
for starting up, and water and hydrogen are stupidly common elsewhere in the solar system
and can be fairly cheaply imported back in later generations. But if it turns out weāre wrong about that
hydrogen and water supply on the Moon, it just shows we have different options, and
also shows us our pathway to mass-producing metals there too. Many of which are magnetic and would be very
easy to magnetically propel out of a mass driver. We also do not need to achieve the super high
velocities that we have to in order to get off Earth, nor do we need any sort of megastructure
tens of miles high for the tube to open out of above the atmosphere, since there isnāt
one. Done with the right timing, things launching
off the Moon already have a lot of the extra delta v they need to get to a more distant
destination, or vice versa, have their velocity dropped enough to make an orbital insertion
around Earth or to aerobrake down to earth relatively cheaply. We might one day have big orbital installations
around the moon, including lunar elevators or orbital rings, but early on we can probably
get away with a launch tube running over the surface that only has a tube for the sake
of keeping dust out, and thus need not be very substantial. A human ship aiming to achieve low orbit of
the Moon, at around 1 mile or 1.6 kilometers per second, only needs an acceleration track
long enough for 160 seconds of 1 gee acceleration, something like 80 miles or 130 kilometers
of track. Or alternatively, a 4g acceleration of 40
seconds, which would be a rougher ride, comparable to your typical rocket off Earth, but only
need a track a quarter as long, 20 miles or 32 kilometers. And a cargo launcher sending relatively dumb
matter, just sheets of panel or ingots of metal, probably could get away with 40 gees
or more, a 4 second acceleration down a mere 2 miles or 3.2 kilometers long, and short
enough you might just leave this out in the open on a flat spot and have a robot run down
the rail before a launch to take any dust off from the last one. In terms of power, this isnāt a trivial
amount either, but it requires no propellant and avoids the rocket equation. So if youāre flinging an object into orbit
of the Moon at 1.6 kilometers per second, you are probably able to pull that off with
a mass driver for an energy cost of a few megajoules per kilogram lifted, making it
a good deal less than electrolysis to make a kilogram of fuel from water, at 4 times
that cost, or cracking oxygen out of rock, at 50 times that cost. Your freight bill goes way down. Longer tracks or higher accelerations could
send you off the Moon with all the speed you need to reach your target, though timing would
be absolutely critical in such cases. Thankfully thereās no weather windows and
delays like we often have for launches from Earth. This is why, while Mars is often contemplated
for colonization, or even Venus or Titan or some asteroids, the Moon is always the best
place to get your start. From there you can stop building and fueling
spaceships on the cheap, with barely enough fuel to get a ship to another planet and with
barely enough radiation shielding to keep the crew from dying. With the moon as your source for fuel and
building materials, we can pre-stage huge amounts of supplies to destinations before
a human ever gets there, and send them faster, and on bigger and better-equipped and shielded
ships. All supported by vastly superior near-Earth
orbital facilities, industries, and habitats. In this way, the Moon becomes our Gateway
to all those other worlds, and the stars beyond. It seems like after over fifty years weāre
finally truly on the road back to the Moon, and while that time gap after Apollo was disheartening
to go through, it is a reminder that to obtain huge goals often means working for a lifetime. The same is true of personal learning too. You donāt just become an expert one day,
the secret to achieving huge learning goals and staying sharp for a lifetime is learning
a little every day. Itās also why many dreams never get off
the ground. The billion-dollar start-up idea, the invention
thatās going to change the world, or the career you know youād love. Because getting the skills and knowledge to
make them happen takes effort. But hereās a secret to beating the odds
and actually achieving your goalsālearning every day on Brilliant dot org. Brilliant is the best way to learn math, science,
and computer science interactively, they have thousands of lessons ā from foundational
and advanced math to AI, neural networks, space, rockets, and more ā with new lessons
added monthly. Brilliantās visual, hands-on approach is
such an effective and engaging way to learnā it makes building a daily learning habit easy. Interactive learning has been proven to be
6x more effective than passive learning, like watching lecture videos, so Brilliant helps
you learn by doing. Create programs with drag-and-drop coding,
interact with charts and graphs, and play around with so many stunning visualizations. Brilliant makes it easy to build a daily learning
habit, and you can try everything Brilliant has to offer, for free, for a full 30 days,
by visiting brilliant.org/IsaacArthur or clicking on the link in the description, and the first
200 people will get 20% off Brilliant's annual premium subscription. Incidentally, Iād imagine many have you
noticed by now that weāve been doing some short form content, a mix of original material
like the Quasar Cannon and clips from some of our compendiums. Iām not sure if thatās permanent feature
of the show or not yet, but I figure I need to release about half a dozen a month for
a few months to see what the effect is, and if itās worth doing. Iām also kinda curious if I can explain
concepts in under 60 seconds, Iām not exactly known for my brevity, but for anyone who is
worried, no we are definitely not replacing any of our normal content with shorts, this
is just added material like our monthly livestream or Scifi Sunday episode or image polls to
help pick future episodes. Regular episodes on Thursdays are still what
this channel is focused on. Speaking of that, next Thursday, July 13th
weāll move on to the idea of moving cities, from those floating through the clouds to
those on massive tank tracks or even legs. Then it will be time for our mid-month scifi
Sunday episode, Robots and Warfare, and a look at the role drones and autonomous machines
might have in the future, along with finding out what the first Rule of Warfare in the
future will be. After that weāll discuss whether or not
lifeforms might be based on ammonia instead of water, and what that might look like. Then weāll continue our look at the future
of warfare with Dropships and planetary invasions or boarding actions. If youād like to get alerts when those and
other episodes come out, make sure to hit the like, subscribe, and notification buttons. You can also help support the show on Patreon,
and if you want to donate and help in other ways, you can see those options by visiting
our website, IsaacArthur.net. You can also catch all of SFIAās episodes
early and ad free on our streaming service, Nebula, along with hours of bonus content,
at go.nebula.tv/isaacarthur. As always, thanks for watching, and have a
Great Week!
All I want for X-mass is a rover that moves 11 km/hr.
Powered by solar cells that point straight up.
Because it will always be noon, as it circles around the moon.
Damn. I had an idea to post on here when I watched it on nebula, and now I lost it.
What if we redirect a comet to crash onto the moon? Then we could have access to all those water.
Never thought of a Thermite rocket, but that's pretty cool. If you're already smelting the aluminum to get the fuel for it, then you can probably stamp out cylinders for it to use as solid rocket thrusters.
I'm not sure you'd ever use those for anything carrying people, since solid rockets can't be throttled - you basically have to use an explosive to shut them off once ignited. But they might be useful for carrying non-personnel payloads around.
I'm really not fond of using too much of the Moon's scarce water-ice as expendable propellant, so I'd hope we get those mass driver systems set up quickly. It's smaller than I thought - even the 80 mile version mentioned wouldn't be too bad, and you'd time the launches so they could probably use the non-stop solar power during the long lunar days.