Lava Tubes on the Moon Maintain Comfortable Room Temperatures Inside(universetoday.com)
universetoday.com
Lava Tubes on the Moon Maintain Comfortable Room Temperatures Inside
https://www.universetoday.com/156932/lava-tubes-on-the-moon-maintain-comfortable-room-temperatures-inside/
10 comments
I can’t wait until we set up base, blow up a large sporting arena and get the moonball games televised! If everyone on earth wants to watch something, then it can make money. And then, finally, we have a financial incentive for moon infrastructure. Moon sports ftw!
The moon is in general a better place than Mars for a first attempt at a space settlement in part because there's more options for monetization. It might not pay for the whole thing but it would at least offset it a bit.
There are other big reasons too, like help being only days away instead of months away in the event of a catastrophe.
Once we figure out how to do a space settlement on the moon, then we could try Mars. Mars is likely a better long term home for humans but it's about 60X as far away in terms of travel time.
There are other big reasons too, like help being only days away instead of months away in the event of a catastrophe.
Once we figure out how to do a space settlement on the moon, then we could try Mars. Mars is likely a better long term home for humans but it's about 60X as far away in terms of travel time.
> There are other big reasons too, like help being only days away instead of months away in the event of a catastrophe
Just imagine you need complec heart surgery - you can make it from the moon to a hospital in 3 days. On mars, you are probably dead
Just imagine you need complec heart surgery - you can make it from the moon to a hospital in 3 days. On mars, you are probably dead
If you're in such serious condition that the moon base doctor can't repair it on the moon, then you're probably not going to survive liftoff from the moon, 3 days in transit with whatever life support can be provided by your fellow astronauts, and then withstand landing and final transport to a hospital.
Moon liftoff is relatively gentle… the Apollo lunar module didn’t have seats… the astronauts stood during landing and ascent. It experienced like a half a G.
It's not the liftoff you have to worry about, it's the landing. Apollo 11 had more than 6G during reentry. https://history.nasa.gov/afj/ap11fj/27day9-entry.html
Yes, Moon gravity is very low. If you can't handle liftoff from the Moon, you can't handle a helicopter ride either.
Not only that, a Lunar space elevator to L1 can be fabricated from Kevlar.
Now, you do need 50,000 km of Kevlar, and that sounds like a lot until I tell you that there are 1.2 million km of submarine cable right now. We got this one.
Now, you do need 50,000 km of Kevlar, and that sounds like a lot until I tell you that there are 1.2 million km of submarine cable right now. We got this one.
It's not so much the amount of material that seems daunting, it's getting it to lunar orbit.
If my calculations are right, 50,000km of 5cm kevlar cable (which probably isn't nearly thick enough near the top) would weigh over 500,000 metric tons. Which would take around 25,000 Falcon Heavy launches to get to the moon
I hope it can be manufactured on the moon or on an asteroid or something.
If my calculations are right, 50,000km of 5cm kevlar cable (which probably isn't nearly thick enough near the top) would weigh over 500,000 metric tons. Which would take around 25,000 Falcon Heavy launches to get to the moon
I hope it can be manufactured on the moon or on an asteroid or something.
> 500,000 metric tons. Which would take around 25,000 Falcon Heavy launches to get to the moon
Starship can apparently take 100t to the moon which would be 5000 launches. Elon math has cost per launch eventually reaching $2m which would mean $10b to get the cables to the moon. If terminally optimistic Elon math is roughly correct that puts the project into merely unlikely territory rather than impossible.
Starship can apparently take 100t to the moon which would be 5000 launches. Elon math has cost per launch eventually reaching $2m which would mean $10b to get the cables to the moon. If terminally optimistic Elon math is roughly correct that puts the project into merely unlikely territory rather than impossible.
even if Elon math is off by a factor of ten thats still $100 billion which IIRC is less than the cost of the ISS without even accounting for inflation.
Starship is planned to take 100T to LEO. I think getting to the moon (and landing softly on it) would reduce that figure substantially (or increase the cost/time due to LEO refueling prior to translunar injection).
> Starship is planned to take 100T to LEO
The SpaceX website says “100+ t” to LEO. So 100t is a lower bound? Who knows? [1]
However: “Starship can land 100 tons on the lunar surface," said Aarti Matthews, Starship Human Landing System program manager for SpaceX.” [2]
Aarti may mean “with refueling in LEO” so that would require additional launches without an established orbital refueling station. So to fix my math would require knowing the cost of tanker launches which I’m not going to attempt to do.
1. https://www.spacex.com/vehicles/starship/ 2. https://arstechnica.com/science/2022/05/spacex-engineer-says...
The SpaceX website says “100+ t” to LEO. So 100t is a lower bound? Who knows? [1]
However: “Starship can land 100 tons on the lunar surface," said Aarti Matthews, Starship Human Landing System program manager for SpaceX.” [2]
Aarti may mean “with refueling in LEO” so that would require additional launches without an established orbital refueling station. So to fix my math would require knowing the cost of tanker launches which I’m not going to attempt to do.
1. https://www.spacex.com/vehicles/starship/ 2. https://arstechnica.com/science/2022/05/spacex-engineer-says...
Unfortunately, Kevlar is a carbon-based polymer, and carbon is in short supply on the Moon.
Perhaps the carbon could be flown to the Moon from Earth, and combined there with the available oxygen and hydrogen to manufacture kevlar. (Not sure about nitrogen; is that available on the Moon?)
There's a small amount that gets embedded by the solar wind, but not enough to be extracted practically.
> such serious condition that the moon base doctor can't repair it on the moon
Imagine you are one of the first 100 people on the moon, how many doctors will they have, 1? 2? How much medical equipment will they have, how large does the base get before they ha e an x-ray? Will they even have a dentist?
Are they going to have an MRI to find out why you have persitent pain in the chest? Are they even going to have a surgical theater?
They definately won't be able to do a liver transplant. But they might not even be able to do something basic like fix a broken jaw and a root canal.
Imagine you are one of the first 100 people on the moon, how many doctors will they have, 1? 2? How much medical equipment will they have, how large does the base get before they ha e an x-ray? Will they even have a dentist?
Are they going to have an MRI to find out why you have persitent pain in the chest? Are they even going to have a surgical theater?
They definately won't be able to do a liver transplant. But they might not even be able to do something basic like fix a broken jaw and a root canal.
I don't think G-force sensitivity and difficulty of operation are especially correlated.
Both the moon and mars likely have similar problems for human settlement. Both have highly abrasive dust ready to shred machinery, no breathable atmosphere, and limited gravity. In principal there may be greater concentrations of carbon on Mars for various purposes.
All dust is abrasive (or at least as abrasive as a material of that hardness can be) when it's new and yet to be worn down by the environment. God knows how many machines are rolling around mines, foundries and scrap yards as you type this. Moon dust is only an issue insofar as the kinds of people who wind up doing aerospace engineering don't tend to have the kinds of work backgrounds that make one good at designing things for low margin industrial environments so they're apt to make rookie mistakes in that area. This isn't a hard problem. Every major rubber components manufacturer probably has some gray beard who can look at your dust under a microscope and then tell you exactly what you need to do for your application.
The huge temp swings, now that's actually a real problem.
The huge temp swings, now that's actually a real problem.
Dust on Mars isn't nearly as bad, because it's been worn down by the weather processes there. Moon dust isn't like this.
I though mars also has water which would be hugely helpful.
Neither of the celestial bodies have mediums for growing food in so that either has to be manufactured or carted over. Either way it’s a huge challenge to overcome.
Neither of the celestial bodies have mediums for growing food in so that either has to be manufactured or carted over. Either way it’s a huge challenge to overcome.
So does the moon[1]! It is also a much shorter drive away.
1: https://moon.nasa.gov/news/155/theres-water-on-the-moon/
1: https://moon.nasa.gov/news/155/theres-water-on-the-moon/
If only we had some other long term home closer at hand.
One that we keep digging in instead of digging asteroids, the moon or mars. It’s like taking a poo in your living room because you already have the space available. We should offload all destructive resource gathering off this planet, precisely so we keep our home clean.
This is very correct.
Earth is a treasure of life and biology. Space is filled with endless resources but no known life.
The equation is very, very simple. Protect the life on Earth at all costs and reduce interference in natural evolution. Migrate off-world to barren wastes and mine them.
Every feasible activity that can be done off world, should be.
Use those space resources to build self-sufficient extra-terra systems and eventually migrate all modern / advanced tech off of earth, and remove all traces of our existence there so that new intelligence can take root.
Leave behind only humans who live simply.
Earth is a treasure of life and biology. Space is filled with endless resources but no known life.
The equation is very, very simple. Protect the life on Earth at all costs and reduce interference in natural evolution. Migrate off-world to barren wastes and mine them.
Every feasible activity that can be done off world, should be.
Use those space resources to build self-sufficient extra-terra systems and eventually migrate all modern / advanced tech off of earth, and remove all traces of our existence there so that new intelligence can take root.
Leave behind only humans who live simply.
The planet has a limited lifespan anyway and even if we somehow manage to clean everything up we’d still reach and endgame, and so will all living things. Life tends to spread but non intelligent life is limited in what it can achieve. Therefore it is our duty to spread outside the boundaries of earth, because with us, other life forms will follow. Crazy as it may sound but we are likely biologically programmed to do so but we haven't reached the right level of understanding it yet.
I agree, but I think many of us have this understanding. We are just largely ruled by a people who utterly lack it. I would even argue we have all had it for thousands of years. Most spiritual traditions have it embedded in their teachings, so there has been a “knowing” of our cosmic destiny for a long time I think.
This is my first exposure to Extropian Viridian Anarchoprimitivism. I'm not sure I like it but I'm intrigued.
> Protect the life on Earth at all costs
There will eventually be a threat to Earth's biosphere that we simply lack the technology to divert, avoid, or remediate. Pretending that this isn't true eventually results in human extinction.
There will eventually be a threat to Earth's biosphere that we simply lack the technology to divert, avoid, or remediate. Pretending that this isn't true eventually results in human extinction.
Agreed.
Rogue black holes, gamma ray bursts, or even the very fundamental constants of known physics shifting to a more stable form and that new rule propagating at light speed imperceptibly — and countless, countless other possible dangers. We are no where near the technological level to deal with these, as we cannot even deal with simpler world-ending events (meteor strikes, desertification, proper stewardship of emerging AI, nuclear war).
In addition to all the other reasons one can muster, our advancement in technology can easily be motivated and justified by the objective of Earth preservation and propagation.
It will be interesting to see, however, as we potentially discover other forms of life maybe in places we actually think are barren, how we as a species cope with that. But we are not even remotely at that problem space yet.
Rogue black holes, gamma ray bursts, or even the very fundamental constants of known physics shifting to a more stable form and that new rule propagating at light speed imperceptibly — and countless, countless other possible dangers. We are no where near the technological level to deal with these, as we cannot even deal with simpler world-ending events (meteor strikes, desertification, proper stewardship of emerging AI, nuclear war).
In addition to all the other reasons one can muster, our advancement in technology can easily be motivated and justified by the objective of Earth preservation and propagation.
It will be interesting to see, however, as we potentially discover other forms of life maybe in places we actually think are barren, how we as a species cope with that. But we are not even remotely at that problem space yet.
That'd make a great sci-fi world setting: primitivists who occasionally hop in their spaceship and plug into a superintelligence.
Seriously though: I do think a far future option for preserving the Earth is to move at least heavy polluting industries off world. All technology is not going to happen but we could put Shenzhen on the moon. I could see the moon being Earth's industrial park.
Seriously though: I do think a far future option for preserving the Earth is to move at least heavy polluting industries off world. All technology is not going to happen but we could put Shenzhen on the moon. I could see the moon being Earth's industrial park.
It would be interesting.
On the front of moving industry off world, it does not need to be far future. In fact, we really should have gotten on this years ago already.
We are behind schedule.
Our aversion to nuclear tech has set humanity back decades. Chemical rockets are not sustainable. Nuclear fusion rockets would be, but fear of nuclear fission made society largely afraid of all things nuclear & reliant on oil based energy gen, and the advent of dirt cheap solar allows us to have more time being afraid & using energy sources that constrain us to Earth’s surface.
Use of nuclear energy comes with it a more educated world populace wrt nuclear engineering (nuclear physics is more or less completely understood so the adventure here is in engineering and material sciences). With that more educated populace comes miniaturization of nuclear reactors, materials that can handle radiation better, perhaps even materials that can generate charge when struck by radiation such that most energy is captured in a usable form instead of generating unstable isotopes (think: like solar panels but for alpha / beta / gamma radiation). It also means more people with the background to make fusion a reality.
With fusion reactors comes fusion rockets. Contained plasma has a cool feature of being useful as a clean, high-energy matter stream that can be ejected (and imparting force) while simultaneously generating energy, all while potentially requiring orders of magnitude less reactant mass. This would completely change our relationship with space.
On the front of moving industry off world, it does not need to be far future. In fact, we really should have gotten on this years ago already.
We are behind schedule.
Our aversion to nuclear tech has set humanity back decades. Chemical rockets are not sustainable. Nuclear fusion rockets would be, but fear of nuclear fission made society largely afraid of all things nuclear & reliant on oil based energy gen, and the advent of dirt cheap solar allows us to have more time being afraid & using energy sources that constrain us to Earth’s surface.
Use of nuclear energy comes with it a more educated world populace wrt nuclear engineering (nuclear physics is more or less completely understood so the adventure here is in engineering and material sciences). With that more educated populace comes miniaturization of nuclear reactors, materials that can handle radiation better, perhaps even materials that can generate charge when struck by radiation such that most energy is captured in a usable form instead of generating unstable isotopes (think: like solar panels but for alpha / beta / gamma radiation). It also means more people with the background to make fusion a reality.
With fusion reactors comes fusion rockets. Contained plasma has a cool feature of being useful as a clean, high-energy matter stream that can be ejected (and imparting force) while simultaneously generating energy, all while potentially requiring orders of magnitude less reactant mass. This would completely change our relationship with space.
Gathering resources isn't the really destructive part. Using and eventually disposing of those resources is the what is ruining the planet, not digging them up.
Open pit mining (for coal) is literally destructing all landscape, along with forests and villages. And gold mining and co. uses some very nasty chemicals. Etc. Etc. So sure, burning coal is dirty, but so is extracting it. But since space mining is a really long term project, I would first try to make the processes here on earth a bit better. (With the challenge of raising the standards globally)
I imagine there’s plenty of space in … space to slingshot garbage far enough that we’d never have to worry about it again.
Just because mining isn’t popular in the media, it doesn't mean its clean. The amount of pollution and destruction it causes is unimaginable.
Let alone the dependency on non democratic countries for rare resources, which just like oil and gas, are finite.
Just because mining isn’t popular in the media, it doesn't mean its clean. The amount of pollution and destruction it causes is unimaginable.
Let alone the dependency on non democratic countries for rare resources, which just like oil and gas, are finite.
The problem with slingshotting things is the enormous energy required to escape the gravity well.
Space based manufacturing will be a thing. Raw material import/export is prohibited by the laws of physics.
Space based manufacturing will be a thing. Raw material import/export is prohibited by the laws of physics.
> Space based manufacturing will be a thing.
That is preferred. Why manufacture anything here when you can have better processes outside. I.e.: welding works better outside earth's atmosphere through cold welding. Pretty sure there may be other manufacturing processes that can be done better out there with the aid of bots and little human interaction.
> the enormous energy required to escape the gravity well.
Enormous based on what we know so far. I am sure if we put effort we'd reach far. I imagine people 100-200 years ago thought building massive metal based ships that carry thousands of people and are the size of a building block required enormous energy. Yet we do it for fun these days.
That is preferred. Why manufacture anything here when you can have better processes outside. I.e.: welding works better outside earth's atmosphere through cold welding. Pretty sure there may be other manufacturing processes that can be done better out there with the aid of bots and little human interaction.
> the enormous energy required to escape the gravity well.
Enormous based on what we know so far. I am sure if we put effort we'd reach far. I imagine people 100-200 years ago thought building massive metal based ships that carry thousands of people and are the size of a building block required enormous energy. Yet we do it for fun these days.
The energy requirements can’t change. That’s the laws of physics part.
All we can do is figure out economically viable ways of producing and using that energy.
Enormous ships use enormous amounts of energy. Our ability to harness sufficient energy is what makes those ships possible.
All we can do is figure out economically viable ways of producing and using that energy.
Enormous ships use enormous amounts of energy. Our ability to harness sufficient energy is what makes those ships possible.
The idea that we will move heavy industry off the planet sounded entertaining in the 1970s.
Now it's just sad.
No, space won't save us. We have to stabilize the planet first.
Now it's just sad.
No, space won't save us. We have to stabilize the planet first.
We do, and one of the methods is externalising to space. But yes, we have to stabilise it. Both can be done at the same time, they are not mutually exclusive and neither is to the detriment of the other.
Before any of these things, it would be better to make sure that we survive here, on Earth - and right now, this looks like it's seriously in doubt.
The most popular export from the Moon and Mars will be information. Just basic live streams from daily activities with monthly subscriptions would probably be quite popular.
No, it won't.
It'll be really popular for maybe 6 months, 1 year maximum. After that, everyone will lose interest.
We've already seen this before with the Moon: when Apollo 11 landed on the Moon, everyone in America (and probably all around the world) watched in on TV. With subsequent missions, no one cared, except when there was a big problem with Apollo 13 and the astronauts' lives were at stake.
It'll be really popular for maybe 6 months, 1 year maximum. After that, everyone will lose interest.
We've already seen this before with the Moon: when Apollo 11 landed on the Moon, everyone in America (and probably all around the world) watched in on TV. With subsequent missions, no one cared, except when there was a big problem with Apollo 13 and the astronauts' lives were at stake.
Sure, things would subside after a time, but with a large community there would be a diverse enough range of subjects in content produced to appeal to a broader range of people using media distribution methods on a scale unimaginable to most people in the beginning of the space age.
...and every day parents around the world are making more new fans than ever.
...and every day parents around the world are making more new fans than ever.
"Hey whattup peeps it's ya boy MoonBoi420 coming at you with another update from The Dark Side. Don't forget to smash that like and subscribe button! On today's episode we're going on a trip to The Sea of Tranquility. This will be an exciting vlog! Stick around after this quick word from our sponsor...NordVPN.. Don't let aliens steal your passwords..."
“I THREW MOON ROCKS AT THEIR BASE (PRANK) (FREAKOUT)!!!”
Throwing moon rocks is a funny-once.
GONE WRONG
We found a MOON BUGGY abandoned for 50 Years! WILL IT START?
Perhaps medical treatment would be a great motivator for moon settlement as well. Like, do you suffer from chronic back pain? What about moving to a place where your spine has to support only 1/6 of your Earth weight? I think lots of conditions can become more bearable under reduced g, given the deleterious effects of partial g are not nearly as strong as those under microgravity.
OTOH, you're screwed if you get bored up there after a few years and wanna come back home...
What if I had only a few years left anyway. I think many mobility problems of elderly people boil down to not being strong enough to properly lift and carry around your own weight anymore. Perhaps the moon could be the ultimate retirement home, where people choose to spend their final years enjoying more mobility with reduced risk from falls in lower g.
Will only work if the space elevator happens. The g's from a traditional launch would be a major issue for the elderly.
Luna retirement home!
Another god darn streaming service. Out of this world.
"Welcome to your Space Olympics
All the oxygen has run out
And someone who will not be named
Accidentally hit self-destruct
As you file to your escape pods
I'll distract the alien hordes (you're in the mother** space olympics)"
- Lonely Island, Space Olympics
- Lonely Island, Space Olympics
Once again it seems necessary to remind people just how unsuitable Mars is for human colonization while the Moon is significantly better:
1. Lava tubes will be a cheap form of initial habitable space. Additionally, the Moon is geologically stable;
2. Gravity is too low in both places so you'll probably have to still live in spin gravity;
3. Mars has an atmosphere but it's basically a vacuum. It's just enough to cover all your stuff in dust;
4. Mars is poisonous. The surface is covered in many toxic substances (eg perchlorates);
5. People have a vision of living on the surface of Mars. That'll basically never happen. Radiation is still a problem. Living underground just makes way more sense. And any above ground structure (eg domes) can just as easily be built on the Moon;
6. Distance from Earth is a significant downside to Mars and a significant advantage for the Moon. You can still maintain real-time communication with Earth. And supplies are days not months away.
Mars really only has 2 advantages:
1. Day length. Mars day is almost Earth normal. The Moon is tidally locked so its day is ~28 Earth days long; and
2. Day-night temperature differential on the surface. It's really large on the Moon.
Why this matters is that even though you'd be living underground you still need power and solar power is really the best option. On the Moon this means your best options are the poles.
The standard retort is "terraforming". People who say this don't seem to comprehend what a massive undertaking this is. Example: the Earth loses (IIRC) ~1 million tons of atmosphere every year due to Jeans Escape Energy. That doesn't matter on Earth because the atmosphere is so much more massive.
So at actual atmosphere on Mars would have to be so large such that a similar loss would be insigifnicant.
1. Lava tubes will be a cheap form of initial habitable space. Additionally, the Moon is geologically stable;
2. Gravity is too low in both places so you'll probably have to still live in spin gravity;
3. Mars has an atmosphere but it's basically a vacuum. It's just enough to cover all your stuff in dust;
4. Mars is poisonous. The surface is covered in many toxic substances (eg perchlorates);
5. People have a vision of living on the surface of Mars. That'll basically never happen. Radiation is still a problem. Living underground just makes way more sense. And any above ground structure (eg domes) can just as easily be built on the Moon;
6. Distance from Earth is a significant downside to Mars and a significant advantage for the Moon. You can still maintain real-time communication with Earth. And supplies are days not months away.
Mars really only has 2 advantages:
1. Day length. Mars day is almost Earth normal. The Moon is tidally locked so its day is ~28 Earth days long; and
2. Day-night temperature differential on the surface. It's really large on the Moon.
Why this matters is that even though you'd be living underground you still need power and solar power is really the best option. On the Moon this means your best options are the poles.
The standard retort is "terraforming". People who say this don't seem to comprehend what a massive undertaking this is. Example: the Earth loses (IIRC) ~1 million tons of atmosphere every year due to Jeans Escape Energy. That doesn't matter on Earth because the atmosphere is so much more massive.
So at actual atmosphere on Mars would have to be so large such that a similar loss would be insigifnicant.
Mars advantages continued:
3. Available water, required for any human/plant/animal life
4. 2.3 times the gravity of the moon
5. CO2 in atmosphere could be converted to O2 for breathing or methane for rocket fuel
3. Available water, required for any human/plant/animal life
4. 2.3 times the gravity of the moon
5. CO2 in atmosphere could be converted to O2 for breathing or methane for rocket fuel
3* Water also appears to be present on the moon[0]
4* Is that enough? We don't know, we've yet to do any centrifuge habitat experiments with small mammals
5* oxygen is so common, CO2 has the advantage of being gasseous, but silicates, aluminum and iron ores are the rocks you can't throw a rock without hitting and has the advantage that you only need to process a millionth the volume to get an equivalent number of moles to martian CO2.
[0]https://en.wikipedia.org/wiki/Lunar_water
4* Is that enough? We don't know, we've yet to do any centrifuge habitat experiments with small mammals
5* oxygen is so common, CO2 has the advantage of being gasseous, but silicates, aluminum and iron ores are the rocks you can't throw a rock without hitting and has the advantage that you only need to process a millionth the volume to get an equivalent number of moles to martian CO2.
[0]https://en.wikipedia.org/wiki/Lunar_water
Zubrin does a good job of outlining why Mars is better in his book "The Case for Mars.". He's thinking underground structures on Mars with solar panels and some pressurized agriculture up top.
Mars had much less harsh living conditions than the moon and having water and CO2 around makes living off the land, at least partially, a lot easier than on the moon. The delta-v to get to the moon vs. Mars isn't much different. Getting out of Earth's gravity well is the hard part.
Mars had much less harsh living conditions than the moon and having water and CO2 around makes living off the land, at least partially, a lot easier than on the moon. The delta-v to get to the moon vs. Mars isn't much different. Getting out of Earth's gravity well is the hard part.
Really good post thank you.
Issues:
Discovery - Other than spots where part of a lava tube's roof has already collapsed, how quick & cheap is it to discover and map the lava tubes under some non-trivial part of the lunar surface?
Scale - Let's say there's a lovely lava tube, X meters in diameter and Y meters below the surface, in a location where we'd like to build a moonbase. For a give size of moonbase, there will be fairly narrow ranges of X and Y values where the lava tube is actually suitable for housing the moonbase.
Cut & Fill Competition - Lava tubes aren't magical. If an area on the moon has deep, stable "soil" (vs. near-surface bedrock) containing ~few larger pieces of rock, then "dig a trench, install tubular habitat, fill trench back in" may give a far lower cost and/or higher predictability than "starting looking for the perfect lava tube...".
Stability - If you're not familiar with the things that often go wrong when humans start digging and building structures, Practical Engineering ( https://www.youtube.com/channel/UCMOqf8ab-42UUQIdVoKwjlQ ) is a pretty good intro. Note that we have a lot of experience with and data on how to do such things on the Earth. On the moon...not so much. Some very painful and expensive lessons seem inevitable.
Discovery - Other than spots where part of a lava tube's roof has already collapsed, how quick & cheap is it to discover and map the lava tubes under some non-trivial part of the lunar surface?
Scale - Let's say there's a lovely lava tube, X meters in diameter and Y meters below the surface, in a location where we'd like to build a moonbase. For a give size of moonbase, there will be fairly narrow ranges of X and Y values where the lava tube is actually suitable for housing the moonbase.
Cut & Fill Competition - Lava tubes aren't magical. If an area on the moon has deep, stable "soil" (vs. near-surface bedrock) containing ~few larger pieces of rock, then "dig a trench, install tubular habitat, fill trench back in" may give a far lower cost and/or higher predictability than "starting looking for the perfect lava tube...".
Stability - If you're not familiar with the things that often go wrong when humans start digging and building structures, Practical Engineering ( https://www.youtube.com/channel/UCMOqf8ab-42UUQIdVoKwjlQ ) is a pretty good intro. Note that we have a lot of experience with and data on how to do such things on the Earth. On the moon...not so much. Some very painful and expensive lessons seem inevitable.
> If the scientists' gravity analyses are correct, the lava tube near Marius Hills could easily house a large U.S. city such as Philadelphia
https://www.nbcnews.com/mach/science/gigantic-lava-tube-coul...
https://www.nbcnews.com/mach/science/gigantic-lava-tube-coul...
Looking at that article...it appears to show Philadelphia being a mere 1km or so wide. Vs. Wikipedia says that Philadelphia is >350 sq. km. Even if that's not horribly wrong (maybe they figure that New Philly, on the moon, will be a ~1km x ~350km strip?), they still show the bottom of the lava tube being 3km or so below the lunar surface. The moon's gravity may be weak...but just building a few 3km-tall freight elevators, to provide minimal transport to/from the surface, would be a huge infrastructure project. Vs. "Philadelphia" suggests that you'd have ~1.6 million people living down there. And are they figuring that the city will have it's own pressure dome(s), totaling ~350 sq. km., to hold the air in?
At some point, the ideas start to sound like "wouldn't it be great to build a thousand-square-mile tropical island, in this spot where the ocean is only 3 miles deep?" Sure, if you know somebody who'll give you ~5,000 cubic miles of good rock, delivers cheap, and there's no "asteroid impact" in the fine print.
At some point, the ideas start to sound like "wouldn't it be great to build a thousand-square-mile tropical island, in this spot where the ocean is only 3 miles deep?" Sure, if you know somebody who'll give you ~5,000 cubic miles of good rock, delivers cheap, and there's no "asteroid impact" in the fine print.
which would be a bit excessive for a 10 person base, yes?
TIL the moon has lava tubes whoa
https://en.wikipedia.org/wiki/Lunar_lava_tube
https://en.wikipedia.org/wiki/Lunar_lava_tube
There was recently a proposal to send rovers to explore them:
https://en.wikipedia.org/wiki/Moon_Diver_(spacecraft)
Check out the video on this page for a ton of details: https://www.kiss.caltech.edu/lectures/2018_Moon_Diver.html
That particular mission concept was not funded, unfortunately, but I'm hopeful that we'll do something like this soon. As others in this thread have said, aside from just being really cool these lava tubes on the moon (and Mars! https://en.wikipedia.org/wiki/Martian_lava_tube) are an interesting candidate for human habitats.
Check out the video on this page for a ton of details: https://www.kiss.caltech.edu/lectures/2018_Moon_Diver.html
That particular mission concept was not funded, unfortunately, but I'm hopeful that we'll do something like this soon. As others in this thread have said, aside from just being really cool these lava tubes on the moon (and Mars! https://en.wikipedia.org/wiki/Martian_lava_tube) are an interesting candidate for human habitats.
I mean we visited a collapsed lava tube on one of the Apollo missions (15 I think?).
I wanted to know how anyone could know this without having actually measured it. They have modeled it using known regolith/rock insulation values (presumably from the Apollo samples).
> The researchers used computer modeling to analyze the thermal properties of the rock and lunar dust and to chart the pit’s temperatures over a period of time.
I'm not sure I'd trust a lining applied to a naturally-formed tube wall to retain air. But if we were to build our own tunnels with a lunar TBM¹, where we could control what the tunnel wall is like, yeah, that'd be fine.
¹ https://en.wikipedia.org/wiki/Tunnel_boring_machine
> The researchers used computer modeling to analyze the thermal properties of the rock and lunar dust and to chart the pit’s temperatures over a period of time.
I'm not sure I'd trust a lining applied to a naturally-formed tube wall to retain air. But if we were to build our own tunnels with a lunar TBM¹, where we could control what the tunnel wall is like, yeah, that'd be fine.
¹ https://en.wikipedia.org/wiki/Tunnel_boring_machine
The tunnels have been structurally stable for a long time, sealing them seems much easier and more reliable than boring a new tunnel, sealing it, and hoping it remains stable.
What kind of control do you think you'd have that would make the 'artificial' tunnel better?
What kind of control do you think you'd have that would make the 'artificial' tunnel better?
It'd have several desirable properties:
1. You'd have a flat smooth surface that you could apply a liner to, instead of a surface that undulates and (probably) has fissures.
2. The diameter would also be constant, so that you could design your liner to fit based on known dimensions. Curves would also be of a known radius.
3. Also, our tunnel would go exactly where we want, and not wander around based on some ancient flow pattern. Or form oxbows where it loops back on itself.
4. So far as a structural liner, if you look at some of the tunnels under rivers where there is the danger of water intrusion, to my knowledge none of them have ever used a natural formation. Brunel used a brick structural liner under the Thames, and modern TBMs use interlocking concrete panels with rubber gaskets.
1. You'd have a flat smooth surface that you could apply a liner to, instead of a surface that undulates and (probably) has fissures.
2. The diameter would also be constant, so that you could design your liner to fit based on known dimensions. Curves would also be of a known radius.
3. Also, our tunnel would go exactly where we want, and not wander around based on some ancient flow pattern. Or form oxbows where it loops back on itself.
4. So far as a structural liner, if you look at some of the tunnels under rivers where there is the danger of water intrusion, to my knowledge none of them have ever used a natural formation. Brunel used a brick structural liner under the Thames, and modern TBMs use interlocking concrete panels with rubber gaskets.
You seem to be assuming that the whole tunnel should be one continuous structure, and that the pressure vessel must occupy the whole volume. A segmented structure, possibly with pressure vessels that are either flexible or of a smaller diameter than the outer walls may be more practical. I'm also not sure whether luncrete is really a practical option, and you certainly won't have clay for bricks.
I think you're making a lot of assumptions, and don't have a comprehensive view of how the structure(s) would be designed and built.
I think you're making a lot of assumptions, and don't have a comprehensive view of how the structure(s) would be designed and built.
A space station in a bottle. Except the bottle is a lava tube.
They've been structurally stable under a specific, unchanging load for a very long time. If suddenly they are pressurized to 1 atm, that may very well change.
It may, but usually it would mean they are even more durable, since the air pressure works against the gravital pressure from above. But lots of experiments are definitely needed.
Preventing it from collapsing by increasing structural durability seems wise.
The grandparent didn't say anything about reinforcing the TBM-made tunnel, it just asserted that it would be controlled. What techniques would be used for "increasing structural durability" that are only applicable to TBM-made tunnels?
I would expect a lava tube from a drained lava flow to vary greatly. We see many have collapsed over the ages. It would provide an insulated underground tube miles in potential extent. That said, the danger of a roof fall would be low in some spots and ready to fall anytime in others. This is still rock, about 6 tonnes earth mass per cubic meter (one tonne on the moon). That means a very strong tunnel liner is needed. It also needs to be air tight. Research into the use of regolith as an ingredient of a concrete needs to be done. One traditional concreted mass is baking bricks of regolith. More research into brick baking from various lunar materials is also needed. A blown up fabric habitat would work inside this sealed brick tunnel.
Can you do that without water? That would be the ultimate so the little that is available doesn't have to be used in construction materials
With enough energy, one can sinter the regolith together. Using water would be ridiciously expensive, unless some meaningful water reservoirs on the moon are found or an easy way to extract the very little existing water.
Yes, ground regolith and other local minerals might be available to mine - grind to powder, press into a shape(s) that can be Lego'd into the tunnel you want. Sintered blocks are very strong in compression and 1-2 layers will allow long buildings to be made in the lava tubes or on the surface. crushed regolith will serve as insulating berms that embed structures.
There are hints there will be water in parts of the regolith. I am not sure how a water based cement would endure heat/vacuum, or only vacuum cycling - would it crumble? Inner places = less heat, but vacuum is all around. I tend to think that a low temperature melting mineral mix might work to bond blocks - a ceramic solder?
I imagine these bricks will be modeled so they stack easily i.e. legoregolith bricks.
Yes, pressed and shaped they could be baked until they were a strong ceramic load bearing shape that suited wall, roofd, door, ceilings Made with precision molds they would be a tight fit and they could be cemented together with a fusing cement that melted at a lower temperature than the blocks, as water would be hard to find and might fume off into the vacuum. In truth there will be 20-30 years of step by step progress and R&D before we reach the stage of doing this on the moon
> “Because the Tranquillitatis pit is the closest to the lunar equator, the illuminated floor at noon is probably the hottest place on the entire moon,” said Horvath.
With the daily big temperature swings, is this a viable source of power?
With the daily big temperature swings, is this a viable source of power?
[deleted]
Interesting. Much like the temperature underground on earth.
Wait, is there volcanic activity on the moon?
The moon was formed by a massive impact that calved a piece off of Earth. The resulting body formed from accreted material, much of it still very hot from the impact. Since thermal energy has nowhere to go in a closed system like a planetoid except, eventually, radiation, it stayed partially melted for a long time and cooled from the outside in.
Earth is actually undergoing a similar process... IIUC, our planet isn't big enough to generate internal heat, and eventually the core heat should radiate away. I don't know if the time scale for it exceeds lifetime of the sun though.
Earth is actually undergoing a similar process... IIUC, our planet isn't big enough to generate internal heat, and eventually the core heat should radiate away. I don't know if the time scale for it exceeds lifetime of the sun though.
Wikipedia puts the radioactive decay of isotopes at half of the heat flux from the core. So yes, eventually it will cool down, but it is absolutely generating internal heat.
Oh, that is awesome.
I swear, every time I learn a new thing about Earth's internal structure it gets weirder and cooler.
I swear, every time I learn a new thing about Earth's internal structure it gets weirder and cooler.
Not anymore. But there used to be!
Wait… so does this mean the moon really IS made of Swiss cheese?