Lava Tubes on Luna - Why build a lunar space station?

 

" ... a graduate student in Purdue's Department of Earth, Atmospheric and Planetary Sciences, led the study that examined whether empty lava tubes more than 1 kilometer wide could remain structurally stable on the moon.

The Purdue team found that if lunar lava tubes existed with a strong arched shape like those on Earth, they would be stable at sizes up to 5,000 meters, or several miles wide, on the moon.

"This wouldn't be possible on Earth, but gravity is much lower on the moon and lunar rock doesn't have to withstand the same weathering and erosion,” Blair reported. "In theory, huge lava tubes — big enough to easily house a city — could be structurally sound on the moon."  Space.com

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Cosmic radiation is heavy on the surface of the moon.  Without a lot of shielding it will fry your innards.  This Purdue University study tells us that large, long, voids exist below the surface of Luna.  These were evidently created by lava flows long ago.  The study also claims that in the low gravity field of the moon, these tubes would be sufficiently stable to house a large lunar base for mining of rare earths and other activities.

This brings to mind the lunar colony in Heinlein's "The Moon is a Harsh Mistress."  In that novel, the lunar folk were miners whose mineral production was delivered to earth by being fired from rail guns at an impact area in the Pacific ocean from which they were retrieved by ships

For me the possibility of such a colony and base raises the issue of why the US and Russia are intent on building a lunar orbit space station.  Why could not anything that would be done in lunar orbit not be done at a lunar cave base?  pl 

https://www.space.com/28894-moon-lava-tubes-underground-cities.html

https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress

Comments

[Oilman2]

@ jjackson...

I think that the length of the tether and its strength would be much lower than people envision, IF they did not always do things in a hurry. The stresses are related to acceleration and mass, both of which can be managed. There is no reason that we couldn't use multiple steel cables, other than mass and associated lifting cost.

I think the anchor might be more problematic in regolith, as well as setting it in 0g.

[turcopolier]

LeaNder

I really liked the old gal. Phonetically it sounded like dippelshisser to me. it fit this guy perfectly. He could teach seven languages and had little to say in any of them. OTOH he had a beautiful singing voice. pl

[Oilman2]

@ b...

Doppelscheisser?

b, you need to stop blowing everything up with "facts" - it's just a thought exercise.

NOBODY knows what subsurface luna is - there could be aliens in lava tubes watching us via periscope - at this point, nobody can disprove that. They communicate with directed laser bursts so we don't get any radio signals. They have matter converters like on Star Trek for food. They lay eggs on Earth that hatch every 10000 years, and that's why they have the lunar watch station...

The fun thing is, disproving those things is as difficult as proving them.

And before you laugh, less than 1000 years ago, EVERYONE knew the Earth was flat!

[Donald]

I was hoping the ape cave name was a Bigfoot reference, but according to this link it is named after some group of mere humans who called themselves that and explored the cave. Darn.

http://www.wta.org/go-hiking/hikes/ape-cave

Lots of Bigfoot stories from that part of the country, as I remember reading as a kid, but this cave isn’t part of the lore.

[Martin Oline]

Here is a rail gun or "kinetic projectile" video. Unfortunately, they tend to destroy themselves with a few shots. I suppose an environment with little gravity might change the situation.

https://youtu.be/0IeSyi1n7sk

[Donald]

Darn it, I liked your post until the last sentence and now I am going to act like one of those German nitpickers. The ancient Greeks knew the earth was round and Eratosthenes probably made a pretty good estimate of its size— 250,000 stadia, but we don’t know exactly how big a stadia was. Hipparchus and Aristarchus made decent estimates of the moon’ s distance. The ancient Greeks were no dummies and people in the Middle Ages hadn’t forgotten what the Greeks had figured out.

[Babak Makkinejad]

That would be a sheep then.

[Linda]

What fun

[ked]

I support a space exploration model that establishes the systems capability to explore & settle space independently of planets (including Earth), moons & astroids... to transit even light years without having to land anywhere - our crafts will be our worlds. In this model, colonization of natural objects along the way is likely, while mankind’s chance of survival far & wide is enhanced. A robust extention of humanity that provides connectivity via self-sustaining ship-worlds. For Heinlein enthusiasts, think Orphans of the Sky.

[mike]

Donald -

Thanks for that link. But perhaps you were right in the first place. The group that the link pointed out that first explored the cave that called themselves the Mount Saint Helens Apes - I'm thinking maybe they named themselves that because of bigfoot lore.

[Peter AU]

Mining Helium 3 will most likely come in time. But who will do it? A few nations are interested, US, China, Russia. US has managed a lot of showy stuff - sending man to the moon, space shuttle ect. But it is 1960's designed Soyez that ferries astranauts to the ISS. It is soviet designed rocket engines that put US military satellites into orbit.
A pity the US is doing its McCarthy thing at the moment. The combined resources and knowhow of the three countries combined could take space exploration a lot further.

[LeaNder]

Yes, correct, Pat, the German "sch" is mostly pronounced like the English "sh":

In this case, "sch" is a trigraph (a triplet of letters representing a single sound) and pronounced exactly like English "sh."

Easy to image a couple of scenarios. ...

[earlthepearl]

In the Moon is a Harsh Mistress they mined ice to grow wheat. The wheat was sent to earth. It makes no sense because if they could grow wheat in caves on luna they could have just grown it in caves on earth.

[Oilman2]

@ Donald...

LOLOL - 276-195BC? Now didn't I say the last thousand years?? So you are picking at your own nits Big D, not mine, and by an additional thousand years! You know dang well I was just trying to illustrate a point in very broad terms anyway.

But I do enjoy when the Colonel tosses out these little thinking and extrapolating exercises...

[Babak Makkinejad]

I think you are not going far enough in confining yourself to the Solar System.

What is urgently needed is the invention of a mechanism to enable mass migration from Earth.

Currently, the situation on Earth is akin to a prison in which various gangs of prisoners are led by ruthless and viscous leaders who offer them protection at a certain cost.

Every one loathes everyone else and constant fighting and murder - even over otherwise trivial items - are rampant.

And everyone wishes to be out of that prison to resume his life and pursue his own happiness in liberty - never mind the fact that many would not be able to handle that liberty and freedom.

I envision devoting 5% of world's economic output to perform such research. In the ripeness of time, when such a mechanism is discovered and invented and put into practice, extant nations, minorities of all kinds, etc. would be free to emigrate to a suitable Earth-like planet or planets.

The mechanism itself could be based on warp drive, worm-hole, faster-than-light travel of some as yet undiscovered feature or property of the universe.

For example, Jews can move to a planet without a single gentile - thus putting to rest the fear of homicidal anti-Semitic gentile.

Euro-American Protestant can move to one such planet called "America II" - where there are no Catholics, Jews, Muslims, Blacks, Armenians, etc.

There would be a few desert-like planets in which a large number of Muslims - Shia or Sunni - could elect to live in tents and thus live their lives in a "Pure Muslim Manner".

The new inhabited worlds Karnatak, Tamil, and Lanka can exist in splendid isolation from one another - never having to come across a member belonging to that loathed "Other" subgroup.

And needless to say, there would be a large number of planets solely for Kurds - since each valley will have to have its own planet. Like wise for much of sub-Saharan Africa.

In this manner, we could hope that planet Earth could be left inhabited by those who are brave, enlightened, generous in mind and in spirit while all those who crave the security of a parochial existence could rejoice in their newly established but dead-ended colonial existences.

[AEL]

As others have said, the Japanese have found big lava tubes on the moon.
https://www.theguardian.com/science/2017/oct/19/lunar-cave-discovery-raises-hopes-for-human-colonisation-of-moon

[charly]

The energy problem is likely solved before He3 will be mined on the moon so i don't really see the economics behind He3 mining.

[charly]

Finding carbon is also a big problem on the moon. But ice you will find on the moon is probably a mixture of water and carbohydrates.

[charly]

I don't know about the other groups but Euro-American Protestantism has a habit to split up with a big fight. You wouldn't need 1 America II but a million. That is probably true f every other group too.

[JJackson]

Babak it sounds like a great recipe for inter-planetary war. Planet capitalist vs planet communist etc. Until we can get a recipe for living together on this planet it may be best not to inflict humanity on anymore of the universe. If ET is out there and watching us they probably view us much like Trump watching NK at some point they will decide we are too irrational and dangerous to be allowed out of our own solar system and will send in the Vogons.

[different clue]

Peter in Toronto,

The particular variant of that theory I read is that ETs who witnessed our moon landing from a nearby lunar base were the ones to tell us not to return. Is this the particular variant of the theory to which you refer?

[different clue]

As to why a space station around the moon instead of directly on or in the moon, it may be that the Space Powers are treating this as a step-by-step learning-through-doing excercise.

Since we know that we know how to do Space Station, we put a knowable Space Station orbiting around the moon so that we can practice and learn getting from earth to Lunar Space Station and back over and over.

Once we know that, then we can work on learning to colonize the moon's surface and/or interior with the Lunar Space Station right there to support the learning or to flee back to very fast if things go wrong for the learners and developers on or in the moon.

[Babak Makkinejad]

Nah, you just need to make the coordinates obfuscated and unrecoverable.

[Babak Makkinejad]

There are plenty of Earth-like planets out there. Sufficient for everyone.

[turcopolier]

All

it appears that the Japanese government also thinks the caverns will be useful. http://www.news24.com/Green/News/huge-cave-found-on-moon-could-house-astronauts-japan-scientists-20171019 pl