ALL SCI-FI

[Bud Brewster]

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This Gigantic Lava Tube Could Be Home for Moon Colonists

By Laura Geggel, Live Science





The hollow is so huge it could swallow up a big city like Philadelphia.

A city-size lava tube has been discovered on the moon, and researchers say it could serve as a shelter for lunar astronauts.

This lava tube could protect lunar-living astronauts from hazardous conditions on the moon's surface, the researchers said. Such a tube could even harbor a lunar colony, they added.

"It's important to know where and how big lunar lava tubes are if we're ever going to construct a lunar base," study co-researcher Junichi Haruyama, a senior researcher at JAXA, Japan's space agency, said in a statement. [How to Get to the Moon in 5 'Small' Steps]

Humans first landed on the moon more than 48 years ago, but no one has managed to stay there for longer than three days. That's because the moon is a perilous place. It has widely ranging temperatures, and unlike Earth, the moon does not have an atmosphere or magnetic field to protect life on its surface from harsh sun rays and radiation.

Earth also has lava tubes, but they're not nearly as large as the one discovered on the moon. If the scientists' gravity analyses are correct, the lava tube near Marius Hills could easily house a large U.S. city such as Philadelphia, they said.




~ Read more at the site.
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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[alltare]

Wow! Just like Metaluna!

[Krel]

That's all very good. But what happens when they are attacked by the giant, mutant tardigrades, that spawn from the ones that the Israelis let loose on the moon last August.

David.

[Eadie]

Those tardigrades mutated into this:



We'll probably milk them or slaughter them for meat just like the Selenites!

Did you hear about the famous meeting between Neil Armstrong and the original lunar traveler?


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Art Should Comfort the Disturbed and Disturb the Comfortable.

[Bud Brewster]

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Eadie's image from First Men in the Moon suggested several fascinating concepts.

When that movie came out, the giant caverns seemed like a huge exaggeration of anything we might really find beneath the lunar surface. But the diagram below which shows the predicted size of just one of the caverns — with the city of Philadelphia occupying a surprisingly small area at the bottom — dwarfs anything we saw in the Harryhausen movie!

I realize that the drawing below is just a simplified representation of the size of the cavern, but that thing is SO large I can't help wondering if it could be filled with air and turned into a subterranean lunar world.





That thing is so big that if we filled it with air, it might actually have it's own weather! And if the water ice at the lunar south pole could be transported there, we could have one hell of lake!





The engineering challenges of making the cavern habitable would take a century, at least. The existence of interconnecting lava tubes would make it extremely difficult to seal of the giant cavern so that it held in the air.

The big opening on the surface would have to be equipped with a giant airlock which allowed spacecraft to land and be brought inside.





On the other hand, the numerous lava tubes that branch off from the big cavern would actually have positive side; they'd allow us to expand our underground lunar colony over the next thousand years.

But how could we light such a huge cavern?

Well, the Moon provides ample sunlight for solar panels. But it would be more fun to borrow an idea from the Selenites!





A giant mirror-or-prism at the top of the opening could focus sunlight downward, just like in the movie. At the bottom of the shaft would be a large layer of prisms to refract the light outward and illuminate the cavern below.

This would only work during the lunar "day" in the area where the opening is located. Other means to illuminate the colony would be needed during the 14-day lunar "night".

All this sounds great, of course . . . except that the giant mirror-or-prism interferes with the large airlock which the main opening would need. Obviously it would be best to position the airlock at the bottom of the shaft so that it would be partially protected from meteorite strikes.

I haven't figured out a way to have both the airlock doors and the layer of prisms which would defuse the sunlight. I suppose a large "porthole" could be included in the upper airlock door to pass the sunlight through, and a larger porthole made of faceted prisms could be part of the lower door.

Picture the plastic panels that cover neon lights; they break up the light which passes through and diffuse it in all directions.

The big mirror-or-prism at the top of the shaft would have to be moved out of way whenever spacecraft arrived or departed. The best way to do that would be to mount it on a moveable arm which could be rotated to one side until the opening was clear, and then rotated back into position.

As you can tell, guys, I'm pretty excited by the discovery that good old Mother Nature provided us with these amazing subterranean chambers for a thriving underground lunar civilization.

And I just found an article on the subject call Moon colonization – many lava tube caves, water, and high amounts of titanium which features this artist conception of the lunar colony inside a lava tube.





Notice the ceiling which diffuses the light from above the way I described it (more or less . . . ).

And the title suggests that the area contains plenty of water and lots to titanium for construction purposes!

Could this get any better or what!
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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[scotpens]

[Bud Brewster]

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You are SO right, scotpens!

Somewhere on All Sci-Fi there are YouTube videos of Lunar Olympics which show wonderful CGI images of athletes performing amazing feats in the lunar gravity.

I'll try to find them and re-post them here.
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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[Krel]

The problem with using the caverns without habitats is that the cavern walls and floor would have to be sealed to prevent the air from leaking out. They would either have to fuse the rock by heat (LASERs?), or with a coating. Considering the sheer volume of surface area, it would take a mind boggling amount of coating material. Heat fusing seems like the best option as it would add strength to the walls, and not add stress as a coating would.

Depending on the size of the cavern opening, constructing a cap to cover it AND making it airtight could be very difficult. You're going to want a lot of overlap for safety.

The project, when completed would truly be an amazing feat of engineering.

David.

[Bud Brewster]

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This wonderful illustration —





— suggests that in the beginning we'd build enclosed "mini-cities" on the floor of main cavern which provided pleasant environments for the colonists.

As the project progressed, larger coverings like the one shown above would be built over the initial ones, with new habitats constructed around the small ones. Eventually the larger habitat would become self sufficient, and the smaller shelter inside the newer one would be removed.

This procedure could progress until the entire cavern floor is covered, while the construction crews continue to seal off the walls of the cavern until it finally became a central hub for all the branching portions of the colony which are connected by the lava tubes.

The sealed lava tubes would be opened whenever a new community inside a tube was ready to join the main cavern.

Think of this as Atlanta being connected by all the roads and highways which branch out to the smaller towns that surround it.


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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[alltare]

"Rendezvous with Rama" might give you a few more ideas, Bud.

Considering that a lunar day is an Earth-month long, the Selenite's idea of reflecting sunlight directly into to lunar chamber seems like doing it the hard way. It's difficult to store sunlight for use weeks later other than by converting it to some other form, like heat or electricity, and if you're going to convert light to electricity, solar panels would probably be necessary to catch the light that you have reflected into the cavern.

Photovoltaic panels external to the cavern would be much simpler: Outside, you have all the space you would ever need for enough panels to power the cavern . Having that external source of electricity, there would be no need for giant windows in the airlock doors or the chamber's ceiling, or anywhere else. Just run some wires to wherever power is desired. There's very little "airborn" dust on the moon, so the outdoor panels would seldom require cleaning maintenance. Because there's no sunlight absorbing atmosphere, their output would be much greater than it would be on Earth. And since they're outside, direct sunlight instead of attenuated reflected light would impinge on the panels, resulting in higher output.

If the cost of solar panels is too high or their output isn't large enough, the moon would be the ideal place to use nuclear reactors. It's possible that this would be cheaper by far than any other method. Like the solar panels, the reactors could be located miles away from the cavern, with power lines connecting them to the habitat.

I don't think the moon has much internal heat- it's essentially dead- so geothermal power is probably not an option.

[Bud Brewster]

[Bud Brewster]

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This video by science expert Fraser Cain is an excellent presentation of the "lava tube colony" concept, and at the 4:30 mark he talks about sealing the walls and then pressurizing the caverns.

____ Living Underground on Other Worlds. Lava Tubes


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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[Krel]

I have to wonder which solar option is the most efficient. Solar panels convert electricity directly, solar boilers are basically steam engines. Which one gives the most power for it's size? Which one is the easiest to maintain, and can survive the environment the best.

With the long periods of no sunlight, atomic power is going to be needed. Burying the reactor structure, either underground, or piling soil on top of the structure is going to be a must. As was pointed out, the reactor doesn't need to be near the colony, so you could build it in the next crater, and as large as your needs dictate. You would have to bury the power lines to protect them from the environment. Reactor waste storage shouldn't be a problem. You can either bury it, or send it on a journey to the Sun. If you can build a mass driver, then solar disposal would seem to be the best option. You could use the mass driver to dispose of any waste you don't want around. It could be an industry, Earth sends up it's dangerous waste, and you just chuck it into the sun.

If fusion power becomes a real thing, then you wouldn't need to use an atomic reactor, except maybe as a backup and for research.

David.

[Bud Brewster]

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David, that is an excellent analysis of the problem and the various options which are available.

I'll begin by admitting that the only two places on the Moon which could take full advantage of solar power are the North and South Poles. And I confess that my lunar colony dreams have long been focused on those locations.

It's so easy to imagine a ring of solar panels along the rim of a polar crater which contains a lunar city, with the sun going 'round and 'round while it shines on each section, and the crater wall keeping the lunar city from ever feeling the searing heat of the sun!





That's been my dream . . . until now.

But these lunar lava tubes are exciting for a different reason! Not only do they provide protection from the harsh sunlight, they also protect the colony from both meteorites and cosmic rays!





And even though the areas with the known lava tube's "skylights" (as they're called) don't have that sweet advantage of constant sunlight, it just breaks my heart that we might have to build those damn dangerous nuclear power plants on the Moon!

Movies like The China Syndrome and real events like Chernobyl and the Japanese reactor that was damaged by the March 11, 2011 tidal wave makes me mighty reluctant to place the fate of a lunar colony into the hands of a nuclear reactor.

After all, such a reactor wouldn't just be powering the commercial needs of an Earth-bound community . . . it would be supplying the heat, light, and air for an underground colony on the Moon!

If the reactor had to shut down for just a few days, the colony would be doomed!

However, we don't yet know how many large lava tubes there are on the Moon. There might be several which are located relatively close to one-or-both of the poles!

If so, THAT would be the place to locate our subterranean colonies, and the power could then be supplied by a ring of solar panels around several of the relatively near polar craters!





All I'm saying, David, is that we should explore the idea that our lunar colonies can take advantage of both the lunar lava tubes AND the abundant solar energy which the Moon provides.

After all, those are the two greatest advantages which the Moon offers! Surely there's a way for us to get both of them.
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Is there no man on Earth who has the wisdom and innocence of a child?
~ The Space Children (1958)

[Krel]

Have they said how wide that entrance to the cavern is? It looks pretty wide to me, and covering that might be an engineering feat in itself.

If that entrance was made by a collapse, then you are going to have a miniature mountain on the cavern floor below it. If you have ever been to the Marvel Caverns in Silver Dollar City in Missouri, then you have seen what forms in a roof collapse. The opening perimeter might be a bit fragile, and have to be re-enforced.

David.