Author Topic: Off-World Tunneling & Mining Technologies  (Read 1637 times)

Online sanman

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Off-World Tunneling & Mining Technologies
« on: 10/05/2017 06:04 AM »
At some point, whether on the Moon or Mars or elsewhere, mankind may need to doing tunneling and mining, whether for building underground habitats sheltered from radiation, or for ISRU purposes. The mass of the systems used for these activities will matter, at least in the early period, because the hardware for them will most likely have to be transported from Earth.

One newer technology being considered for mining is Thermal Fragmentation (aka. Thermal Spallation)





Plasma Drilling uses superheated gas, requiring little more than electrical energy (ie. no replacement parts needed)

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





Can either of these become a more lightweight and efficient method of tunneling, including in the lunar or martian environments?


What other technologies might be good candidates for off-world tunneling and mining?

https://en.wikipedia.org/wiki/New_drilling_technologies
« Last Edit: 10/05/2017 07:26 AM by sanman »

Offline A_M_Swallow

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Re: Off-World Tunneling & Mining Technologies
« Reply #1 on: 10/05/2017 01:07 PM »
Currently there are no liquids or gasses on the Moon so any machine that uses them will have extremely high operating costs. Hopefully commercial spacecraft will reduce transport costs from $1 million per gallon.

Power sources are likely to be concentrated sunlight and electricity.

If there is frozen water and other hydrogen compounds at the lunar polls then second generation equipment may be able to burn hydrogen. The ice will have to be mined first.

On Mars carbon dioxide can be extracted from its weak atmosphere. The CO2 can be split into 2CO and O2 using solar powered electrolysis. The carbon monoxide could be burnt as a mobile fuel.

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #2 on: 10/05/2017 10:26 PM »
Since solar power is the most easily accessible form of energy available on the Moon, then is it better to harness the Sun's rays directly by focusing them, or is better to first convert to electricity by photovoltaics and use that to power something?

Harnessing Sun's rays directly by focusing them would avoid a conversion step, and but would require the use of lenses, mirrors and/or fiber optics, which would also incur power loss.

Photovoltaically converting the Sun's rays to electricity would incur a conversion loss, but that electric power would then be fungible towards a variety of uses.

Zaptec is a Norwegian company that mainly makes hardware for electric vehicles, but they have a very small high-voltage transformer that's the basis for an electrically-powered "plasma drill":

http://www.zaptec.com/space
http://www.shackletonenergy.com/news/2015/3/17/us-lunar-mining-company-and-norwegian-technology-company-to-develop-drilling-and-power-solutions-for-operations-on-the-moon


What's the best way to drill on the Moon?

Offline A_M_Swallow

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Re: Off-World Tunneling & Mining Technologies
« Reply #3 on: 10/06/2017 03:35 AM »
Since solar power is the most easily accessible form of energy available on the Moon, then is it better to harness the Sun's rays directly by focusing them, or is better to first convert to electricity by photovoltaics and use that to power something?

Harnessing Sun's rays directly by focusing them would avoid a conversion step, and but would require the use of lenses, mirrors and/or fiber optics, which would also incur power loss.

Photovoltaically converting the Sun's rays to electricity would incur a conversion loss, but that electric power would then be fungible towards a variety of uses.

Zaptec is a Norwegian company that mainly makes hardware for electric vehicles, but they have a very small high-voltage transformer that's the basis for an electrically-powered "plasma drill":

http://www.zaptec.com/space
http://www.shackletonenergy.com/news/2015/3/17/us-lunar-mining-company-and-norwegian-technology-company-to-develop-drilling-and-power-solutions-for-operations-on-the-moon


What's the best way to drill on the Moon?

Different machines can be powered in different ways.

For heat concentrated sun light is probably best. For movement and control electricity is needed.

Offline stefan r

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Re: Off-World Tunneling & Mining Technologies
« Reply #4 on: 10/06/2017 04:23 AM »
Tunneling into ice you can use a mirror(s).  The vapor is valuable so should try to catch as much as possible.  If you do not mind losing it you can tunnel with mirrors only. 

On a large ball like Ceres, Europa, or Chandra you eventually need to reinforce the walls.  A vertical tunnel would accumulate some dust.  You could sublime a side chamber and brush the dust there and then continue down.  Better would be to block the entrance so you can get pressure and liquids.  Pump the liquids to storage.  If you tunnel down to a subsurface ocean it will stop working.

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #5 on: 10/06/2017 04:33 AM »
Here's a competition held annually by NASA



Seem to mainly be about regolith recovery. Nothing particularly tunneling-oriented, though.

Offline KelvinZero

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Re: Off-World Tunneling & Mining Technologies
« Reply #6 on: 10/06/2017 08:43 AM »
Someone mentioned this in another thread:
https://en.wikipedia.org/wiki/Frasch_process

You just bore down two thin pipes and circulate hot liquids or gasses through it to extract sulphur. It seemed particularly relevant to ice mining on somewhere like Mars.

Some more far out ideas:
* Dropping rocks from orbit.
* Mass driver
* Solar pumped laser.

I think the last could be pretty practical on the moon's peaks of eternal light. I imagine massive flimsy parabolic trough mirror towers that rotate very slowly over the month, exciting a thin tube of some lasing medium. This permanent tower could have a mirror at the top to distribute the output to any mining operation within several kilometers.

https://en.wikipedia.org/wiki/Solar-pumped_laser#Current_research
The largest solar-pumped laser is currently being operated by a research facility in Uzbekistan. It is a 1 MW solar input power NdYAG type laser, operating at 3,000 degrees C. It is cooled by distilled water.

« Last Edit: 10/06/2017 10:30 PM by KelvinZero »

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #7 on: 10/07/2017 06:53 AM »
Also, I'd like to ask - is it worthwhile to bring equipment for artificially tunneling on the Moon right away, or would it be better to initially rely on pre-existing natural tunnels and caverns for protected habitation space?

If you go with the former, then you have more choice on where you can locate your underground facilities. But if you go with the latter, then you're dependent on wherever the natural tunnels and caverns happen to be located.

On the other hand, making use of naturally occurring caverns and tunnels (eg. lava tubes) could save you a lot of excavation work. What you'd mainly have to do is spray coat the interior walls and perhaps provide a liner envelope fitted to the dimensions of that interior space. Then you'd fit an airlock over the mouth of the cavern/tunnel for ingress & egress.


Offline A_M_Swallow

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Re: Off-World Tunneling & Mining Technologies
« Reply #8 on: 10/08/2017 04:06 AM »
Also, I'd like to ask - is it worthwhile to bring equipment for artificially tunneling on the Moon right away, or would it be better to initially rely on pre-existing natural tunnels and caverns for protected habitation space?

If you go with the former, then you have more choice on where you can locate your underground facilities. But if you go with the latter, then you're dependent on wherever the natural tunnels and caverns happen to be located.

On the other hand, making use of naturally occurring caverns and tunnels (eg. lava tubes) could save you a lot of excavation work. What you'd mainly have to do is spray coat the interior walls and perhaps provide a liner envelope fitted to the dimensions of that interior space. Then you'd fit an airlock over the mouth of the cavern/tunnel for ingress & egress.



The walls and floor of a lava tube are unlikely to be smooth so rocks will need removing before they can be lined.

IMHO Astronauts will be living in surface habitats brought from Earth for many years before we switch to tubes. The original mines are likely to be strip mines.

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #9 on: 10/08/2017 05:46 AM »
The walls and floor of a lava tube are unlikely to be smooth so rocks will need removing before they can be lined.

IMHO Astronauts will be living in surface habitats brought from Earth for many years before we switch to tubes. The original mines are likely to be strip mines.

So you feel that the underground spaces humans first move into will be ones which initially were being used for resource extraction?

How do we guarantee the stability of such underground spaces before occupying them?

Offline A_M_Swallow

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Re: Off-World Tunneling & Mining Technologies
« Reply #10 on: 10/09/2017 12:41 AM »
The walls and floor of a lava tube are unlikely to be smooth so rocks will need removing before they can be lined.

IMHO Astronauts will be living in surface habitats brought from Earth for many years before we switch to tubes. The original mines are likely to be strip mines.

So you feel that the underground spaces humans first move into will be ones which initially were being used for resource extraction?

How do we guarantee the stability of such underground spaces before occupying them?

The initial habitats will be on the ground.

Online RonM

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Re: Off-World Tunneling & Mining Technologies
« Reply #11 on: 10/09/2017 12:52 AM »
The walls and floor of a lava tube are unlikely to be smooth so rocks will need removing before they can be lined.

IMHO Astronauts will be living in surface habitats brought from Earth for many years before we switch to tubes. The original mines are likely to be strip mines.

So you feel that the underground spaces humans first move into will be ones which initially were being used for resource extraction?

How do we guarantee the stability of such underground spaces before occupying them?

If the tunnels are not stable, then they can't be used to extract resources.

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #12 on: 10/12/2017 04:07 AM »
What's the best way to convert tunnels into living spaces?

Will tunnel walls be heated into glass? Or maybe cement reinforcement walls will be extruded/slathered onto the bare tunnel surfaces?

Or will tunnel dimensions be mapped precisely, so that inner liners can be constructed on Earth to match those dimensions precisely and placed inside those tunnels to make them airtight?

Will tunnels have to be pressurized first before they can be reinforced and converted into living spaces? Or can that work be done in the still evacuated tunnels, which would later be pressurized towards the end of the process?
« Last Edit: 10/12/2017 06:41 AM by sanman »

Offline KelvinZero

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Re: Off-World Tunneling & Mining Technologies
« Reply #13 on: 10/12/2017 06:31 AM »
Dunno.. perhaps it is a bit like sealing a pool?

http://www.swimmingpoolsteve.com/pages/pool-paint.html

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #14 on: 10/12/2017 06:46 AM »
Perhaps megawatt laser diodes powered by large solar arrays could become a mining tool of choice.

Offline Asteroza

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Re: Off-World Tunneling & Mining Technologies
« Reply #15 on: 10/12/2017 08:03 AM »
What's the best way to convert tunnels into living spaces?

Will tunnel walls be heated into glass? Or maybe cement reinforcement walls will be extruded/slathered onto the bare tunnel surfaces?

Or will tunnel dimensions be mapped precisely, so that inner liners can be constructed on Earth to match those dimensions precisely and placed inside those tunnels to make them airtight?

Will tunnels have to be pressurized first before they can be reinforced and converted into living spaces? Or can that work be done in the still evacuated tunnels, which would later be pressurized towards the end of the process?

Would a mobile 3D printerhead on an arm used to backfill cavities in a lava tube along with a cutter head on an arm to grind down projections until the tube has proper cylindrical proportions be a suitable compromise? Then spray on latex paint, or go for a final 3D print of final tube liner material?

Offline Bob Shaw

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Re: Off-World Tunneling & Mining Technologies
« Reply #16 on: 10/12/2017 08:57 AM »
Where I live in Glasgow, 90% or so of the local Subway system was built using 'cut and cover' techniques. Obviously, not in the bits where the tunnels go under the River Clyde or the Kelvin! This is simple and cheap, and is just the way that the US built Camp Century in Greenland in the 1950s.

Offline CameronD

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Re: Off-World Tunneling & Mining Technologies
« Reply #17 on: 10/12/2017 10:26 PM »
What's the best way to convert tunnels into living spaces?

Will tunnel walls be heated into glass? Or maybe cement reinforcement walls will be extruded/slathered onto the bare tunnel surfaces?

Or will tunnel dimensions be mapped precisely, so that inner liners can be constructed on Earth to match those dimensions precisely and placed inside those tunnels to make them airtight?

Will tunnels have to be pressurized first before they can be reinforced and converted into living spaces? Or can that work be done in the still evacuated tunnels, which would later be pressurized towards the end of the process?

What you can and can't do depends entirely on the material you're working with.  If it's solid basalt, then you probably don't have to seal it but drilling/tunnelling into it is going to be a real b**ch.  If it's softer stuff (similar to limestone or sandstone) then it's more workable but, being porous, may or may not need some kind of sealing.

There are many places on Earth where to escape the harsh environment, entire communities live underground so the techniques required are well refined already. For example:


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


IMHO, it's more likely a type of 'cut-and-cover' - an impermeable roof over a crater - would be a first step on the moon, with digging commencing shortly thereafter.  :)
 
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Online sanman

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Re: Off-World Tunneling & Mining Technologies
« Reply #18 on: 10/13/2017 01:14 AM »
What you can and can't do depends entirely on the material you're working with.  If it's solid basalt, then you probably don't have to seal it but drilling/tunnelling into it is going to be a real b**ch.  If it's softer stuff (similar to limestone or sandstone) then it's more workable but, being porous, may or may not need some kind of sealing.

There are many places on Earth where to escape the harsh environment, entire communities live underground so the techniques required are well refined already. For example:

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

IMHO, it's more likely a type of 'cut-and-cover' - an impermeable roof over a crater - would be a first step on the moon, with digging commencing shortly thereafter.  :)

Wouldn't a crater be considered a more exposed area? Wouldn't it be better to tunnel into a mountainside instead? (Or, I suppose tunneling into the side of a crater wall would do, but that could likely encounter the harder re-solidified rock)

Would non-contact methods like lasers or solar-focusing lenses be better, or would the traditional contact grinding/drilling heads be simpler and easier?
Does anybody use lasers for tunneling or drilling into the ground here on Earth? Just wondering if the technology exists or is already in development.

Offline KelvinZero

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Re: Off-World Tunneling & Mining Technologies
« Reply #19 on: 10/13/2017 02:20 AM »
I couldn't find any mention of current uses, just some research. Lasers are mentioned here along with some other interesting options.
https://en.wikipedia.org/wiki/New_drilling_technologies

Not being used yet on earth does not necessarily kill the idea of course. For space applications we are probably assuming it could be ok to have a slow, energy intensive approach if it lasts practically forever without maintenance, and needs no hands-on labour.

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