Author Topic: Mining lunar ice  (Read 171103 times)

Offline Hop_David

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Re: Mining lunar ice
« Reply #240 on: 02/03/2014 07:20 pm »
IIRC, the '2 meters of solid ice' idea was the default upper limit on the CPR readings by Chandrayaan-1 Mini-SAR,

Here's the article I've cited many times. It suggested two meter thick ice sheets were a lower limit.

Quote
We interpret this relation as consistent with water ice present in these craters.  The ice must be relatively pure and at least a couple of meters thick to give this signature.

I bolded the word "least".

Offline gbaikie

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Re: Mining lunar ice
« Reply #241 on: 02/03/2014 10:09 pm »
Let's suppose:
Lunar water $1000 per kg $1 million per ton.

Assume one needs to mine 500 million dollars of water within 2 years.
And $1 billion average per year for next 3 years.

So at 1 million per tons. Is 250 tons per year or 1 ton per day.

Next assume lunar rocket fuel is $4000 per kg.
Assume one needs to make 500 million of LH and LOX within 2 year.
And $1 billion average per year for next 3 years.

Assume first couple years LOX and LH near same prices per kg:
LOX $3500 and LH $7000.
So first couple years, LOX: $3500, LH: $7000, And water: $1000.

So at these price levels, the cost to ship LOX to lunar orbit is:
rocket fuel used: $4000, plus price of LOX $3500 Plus cost of use
of rocket to lifts the payload. Or easily more the 8000 per kg.
Or price of water is easily more $5500 per kg.

Can you ship LOX or water from Earth to low lunar orbit for less than this?
How much cost to ship 50 tons of water to lunar orbit.
Or how much does it cost to ship 50 tons of water from Earth to high earth orbit.
So a GTO orbit which has perigee of 500 km is example lowest type cost to High earth orbit-
it's going to stay in orbit, and given enough time and small amount delta-v it could be
gotten closer to lunar orbit, and one not really care if it actually get to Lunar orbit.
One could make rocket fuel from it, and a tug could to bring rocket fuel to Low lunar orbit-
whenever the rocket fuel is needed.

[[This could be complicated, but let's roughly assume it make rocket fuel for twice of
whatever the cost of it's water to be shipped to it.
Moon surface is 4 times cost of water, this is 2 times cost of water. It's cheaper
because it's less delta-v to get to it from Earth and it's environment with more
solar energy available. And we will call it depot business. With market "area"
of GTO, L-points, GEO, and Lunar orbit. We could also call it a rocket fuel depot and junk
dealer. Or it's storing anything and everything- starting with water.
But it's not really a solar energy company or a company that makes rocket fuel.
One could also think of it as a banker or pawn shop. So assume it has 2 billion
to invest/buy and also needs to make 500 million within 2 years. Or 25% return
on whatever money spent within 2 years. So if depot buys a Heavy Falcon payload
it costs less than 1 billion. But we assume it doesn't buy more than 2 billion
dollars in total. And we also assume banker is biggest investor and is taking
the least risks. Or doesn't buy anything until it delivered. The risks is in
safely storing and buying something with less value than it can to be sold at.]]

Let's make an assumption that whatever cost to ship lunar LOX to lunar orbit
this is about the same price lunar miners etc pay to get stuff to the Moon.
So their cost of LOX at lunar orbit is more than 8000 per kg- maybe within this
price by +10%. So more than $8800 per kg of LOX.
Or cost is to earth to Lunar orbit plus say $9000 per kg to lunar surface.
Or nice round number of $20,000 per kg.
So 500 million buys 25 tons to surface.
So lunar miner will buy 25 to 50 tons delivered to Moon. Or will spend 500 million
to 1 billion to ship whatever needed to the Moon. Or slightly half of shipping costs
is to get from lunar orbit to lunar surface.

Now lunar miner has big problem, it's quite difficult to sell 250 tons of water a year
because it requires a lot of solar energy to convert 250 tonnes of water into rocket fuel
AND one has to have enough market for 250 tons of rocket fuel.
So one solution is lunar miner mines more than just water.
If lunar miner is getting water at 10% concentration, than means one is handling the
remaining 90% of something other than water. So, more 10% could iron ore. Or more 10%
could be magnetic. Or that 10% of magnetic ore before being processed could worth x amount
of dollars. So water would $1000 per kg, and magnetic ore could be $100 to $200 per kg.
OR the miner could process this ore further.
And there is other volatiles other than H20.
So if miner is mining water which 10% concentration or less, the mining water could
less than half the miner's business. Whereas if mining is collecting frost/ice from the
top of lunar surface giving ore of 50% or more of water, the business might be mostly getting
water and other volatiles mixed with water. And if there is chunks or blocks of ice,
it would be water which more pure.

So in some sense mining pure ice is problem for lunar miner- as needs to be less of specialist.
If lunar miner is more of collector as opposed the digging up lots of dirt, the miner's
paid for infrastructure, favors collecting things other than ice. So could focus on collecting
lunar samples which will be exported to Earth. Which make lunar miner a seller of lunar water and
buyer of lunar rocket fuel- will "control" how much lunar samples is exported.
And if miner is doing lots of digging- say purer water but under the surface. Then miner could get
into business of making living space under ground. Do mining work in pressured areas, and once a
volume is mined out, sell it as living area- a lunar base.

Lunar power company. Lunar power company might begin with solar harvesting in Cislunar space- if
depot has water, power company could first get solar panel to orbit to sell energy needed to split
water. I mention this because these arrays in orbit, could eventually be shipped to lunar surface.
A lunar power company could be interested in making solar panels in space, or assembling solar panel
components in space.
So emphasis may be to ship the PV cells from Earth- rather the frames and etc. It may make low efficient
solar energy collector from regolith. It may get used solar arrays from dead GEO satellites- using
the degraded solar arrays and/or repair them. So it's making electrical energy and is focus making
cheap electrical power and selling it.
So such company might have long term goals making solar panels entirely in space- whether from lunar
material or asteriod material.
Here's something related:
Viability of recycling semiconductors in Intel Processors

"This is a speculative class project and needs to be refined before being deployed at any scale."
http://www.appropedia.org/Viability_of_recycling_semiconductors_in_Intel_Processors
More related:
http://www.itjungle.com/bns/bns103107-story01.html
"Once the wafer is cleaned, IBM can use it to calibrate its machinery as it does its chip-making runs--
this is called a monitor wafer--and after it gets a little worn out from use, then IBM can sell it to
the burgeoning solar power industry, which is eagerly looking for raw silicon material from which it
can make solar cells."
Or:
"TI's recycled wafers have produced enough solar panels to supply electricity year-round to
approximately 1,600 homes. Use of solar panels has helped prevent an estimated 10,900 metric tons
of carbon dioxide from being released into the atmosphere, the equivalent to planting half a million
trees."
https://www.ti.com/corp/docs/csr/news_recycling_silicon.shtml
 
So something of the scrap value on dead GEO satellites, can be just the pure silicon, can have frames
and wiring of solar array, and solar cells which have decent efficiency. In order to consider it, one
needs a lot these arrays. And of these some arrays could quite operational, some arrays only value is
smelted  down.
So collecting most/all dead satellites and using pieces of them for near term uses and at some point-
having a ton of non-functioning silicon chips one could used to manufacture high efficient solar panels.
But more tons one has the more viable it is.
And/or if going to buying and shipping large amount of new shiny solar panels made on earth, long term
one should think of what you going to do with the mass in orbit, when they are no longer functioning well.
So if going to be large solar energy company in space, one probably should have a plan of what
going to happen to solar panels at the end of their lifetimes.
Or one can design that solar array may have short lifetime, if you can repair or recycle them- it
changes your business plan.
A lunar power could small company which plans to bought up by larger company, or it start as part
of big company- such GE.
« Last Edit: 02/06/2014 11:23 pm by gbaikie »

Offline Robert Thompson

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Re: Mining lunar ice
« Reply #242 on: 02/04/2014 09:58 am »
After some trawling.

NASA Planning for Mission To Mine Water on the Moon (January, 2014)
http://www.spacenews.com/article/civil-space/39307nasa-planning-for-mission-to-mine-water-on-the-moon
RESOLVE will be happy if it just produces O2.

Lunar polar craters – icy, rough or just sloping? (Vincent R. Eke, December 2013)
http://arxiv.org/pdf/1312.4749.pdf
Main idea here is that the high CPR craters are due to the angle of incidence, and that CPR increases with angle of incidence, and that the anomalous craters are the result of looking down along one slope, recording all that high CPR, and some lower CPR on the lower angle of incidence on the far side of the crater wall, and the crater floor. So this guy, whose earlier papers Spudis quotes, rejects water ice as explanation for high CPR. That being said, the statistical overrepresentation that Spudis refers to of high CPR craters in the high latitudes is something Eke does not seem to address. But then I don't see that Spudis annihilates the concern that Eke raises. So it's worth it for someone to ask Spudis to review the Eke paper and address that concern.

Resource Prospector (Colaprete, October 2013)
http://www.hou.usra.edu/meetings/leag2013/presentations/colaprete.pdf
Overview. Has a notional mission map.

Lunar Superconductor Applications (April, 2013)
http://www.lsa2013.com/LSA2013Flyer.pdf
Conference schedule. Who knew.

Lunar Polar Regolith: Plans to Study in situ and Perspectives of Samples Return (Mitrofanov, 2013)
http://meetingorganizer.copernicus.org/EPSC2013/EPSC2013-475.pdf
Short letter on Russian lunar missions, including cryogenic sample return.

---

Polar Exploration and Reconnaissance for Lunar Studies Return to the Moon, (Clegg, November, 2013)
http://www.fae-journal.org/PaperInfo.aspx?ID=11962
Appears to be an undergrad group assignment to design a lunar program. Useful challenge for kids.

Offline JohnFornaro

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Re: Mining lunar ice
« Reply #243 on: 02/04/2014 02:29 pm »
The basic idea is that the Russian LEND instrument does not have as prophylactic a collimation as was intended...

Prophylactic collimation?  I'll have you know that this is a family site!
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: Mining lunar ice
« Reply #244 on: 02/04/2014 02:43 pm »
Hernalt:

Many thanks for the three posts above, where you collect a good bit of current info on that supposed water ice, and its concentration and location.  It's also good to read about RESOLVE.
Sometimes I just flat out don't get it.

Offline kch

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Re: Mining lunar ice
« Reply #245 on: 02/04/2014 05:49 pm »
The basic idea is that the Russian LEND instrument does not have as prophylactic a collimation as was intended...

Prophylactic collimation?  I'll have you know that this is a family site!

Guess there'd best be no more discussion of Trojan points, then, either ...  ;D

Offline Vultur

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Re: Mining lunar ice
« Reply #246 on: 02/06/2014 01:05 am »
The thing is nobody has yet extracted water from an actual meteorite.

Really? Even a meteorite on Earth? If not why not? Sounds like something Planetary Resources could be working on, far cheaper than any in-space activity - meteorites are not that rare/expensive.

Quote
On the other hand, the Moon probably has Hg at the ppt level. Dealing with that isn't going to be easy, considering that the EPA's drinking water standards are 2 μg/L (i.e., 2 ppb)...

(I assume ppt is parts per thousand, not per trillion?)

Could it be removed by distillation? Mercury boiling point is way different from water...


Offline gbaikie

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Re: Mining lunar ice
« Reply #247 on: 02/06/2014 02:12 pm »
Quote
Lunar Polar Regolith: Plans to Study in situ and Perspectives of Samples Return (Mitrofanov, 2013)
http://meetingorganizer.copernicus.org/EPSC2013/EPSC2013-475.pdf
Short letter on Russian lunar missions, including cryogenic sample return.
From above:
"Surprisingly, some Extremely Cold Regions (ECRs) were discovered to lie
not only inside but also outside the Permanent Shadow Regions (PSRs)"

The high latitudes of the Moon [and Mercury] are very different, than lower latitudes that
spacecraft have been sent to Moon

Unlike Earth and Mars due to lack of atmosphere.
So starting at 60 degree latitude the highest the sun gets is about 31.5 degrees above the horizon.
So at 30 degree on level ground a 10 foot high post will cast shadow 20' long. Which also means
that level ground will half the sunlight. Or 1/2 of 1360 watts per square meter: 680.
So instead surface warming to 120 C, when sun is only 30 degree above horizon the surface will only
warm to about 60 C.
And at 70 latitude and sun at 20 degrees above horizon, a 10 pole has 27 foot shadow. level surface
gets 500 watts per square meter. Less sunlight than shines on Mars. Or surface warmed to about 25 C.
And at 80 degree latitude, shadow 5 times length, and 272 watts per square meter.
At 85 latitude with sun 5 degree above horizon, a 10' pole shadow is 110'. With 126 watts per square on any level surface. With idea blackbody 126 watt is warms to about 220 K [-52 C]. Pointing a solar panel
at the sun, and you get 1360 watts, but level ground is quite cold. And if on ground sloped up so as to increase this angle, the is ground warmer, and slope other direction it's colder.  And if slope say crater rim at 45 degree facing sun it's surface could be around 120 C.

The axis is at 1.5 degree, so Moon's arctic circle is at 88.5 degrees latitude.
At equinox, sun would be 1.5 degree above horizon at noon. And summer solstice, 3 degree above horizon at noon.
And 3 degrees 10' pole has shadow of 190' with level getting 71 watts per square. Ideal blackbody temperature being about 190 K.
So 71 watts per square is about what Jupiter's moon Europa get when sun is at zenith.
At this angle if one hills on horizon which block 1/2 the sun's disk, it's dividing the 71 watts by 2. But still would have this area fairly well lit.
In terms Lux, on earth full daylight can be 130000 lux. So divide by say 100 and have 1300 lux. And "1000 lux    Overcast day; typical TV studio lighting"
http://en.wikipedia.org/wiki/Lux
Plus when sun is at low angle the surface tend to be more reflective.
So you can have bright surfaces which can be quite cold.

« Last Edit: 02/06/2014 02:15 pm by gbaikie »

Offline Warren Platts

Re: Mining lunar ice
« Reply #248 on: 02/07/2014 08:37 pm »
The thing is nobody has yet extracted water from an actual meteorite.

Really? Even a meteorite on Earth? If not why not? Sounds like something Planetary Resources could be working on, far cheaper than any in-space activity - meteorites are not that rare/expensive.

There are only like 4 known sizeable chunks of CI type meteorites--their first choice. Probably too rare for destructive testing. However, last I heard they have given up on CI asteroids because they are too rare. So second choice is CM meteorites. Problem is the mix of chemicals is such that upon heating, all sorts of compounds are formed except water. There was a thread a while back where a guy who seemed to know what he was talking about pointed this fact out.

Quote
Quote
On the other hand, the Moon probably has Hg at the ppt level. Dealing with that isn't going to be easy, considering that the EPA's drinking water standards are 2 μg/L (i.e., 2 ppb)...

(I assume ppt is parts per thousand, not per trillion?)

ppt = parts per thousand

Quote
Could it be removed by distillation? Mercury boiling point is way different from water...

Probably, might have to triple distill it though. Maybe some reverse osmosis might work. Paragon has been doing some work on how to filter asteroid water--once you get it.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Vultur

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Re: Mining lunar ice
« Reply #249 on: 02/08/2014 07:07 pm »
There are only like 4 known sizeable chunks of CI type meteorites--their first choice. Probably too rare for destructive testing. However, last I heard they have given up on CI asteroids because they are too rare. So second choice is CM meteorites. Problem is the mix of chemicals is such that upon heating, all sorts of compounds are formed except water. There was a thread a while back where a guy who seemed to know what he was talking about pointed this fact out.

Still, if I was running an asteroid mining company I'd want to try it with all different kinds of meteorites I could before I got too far along.

ppt = parts per thousand

It is ambiguous; ppt = part per trillion is also used, and it's what I immediately read it as when you used it. Different fields though, I think - for salinity of water ppt = part per thousand is normal.

Paragon has been doing some work on how to filter asteroid water--once you get it.

Ah, cool. They seem to be doing stuff for a lot of the "new space" companies.

edit: fixed quotes. ++Lar
« Last Edit: 02/11/2014 03:43 pm by Lar »

Offline Warren Platts

Re: Mining lunar ice
« Reply #250 on: 02/09/2014 07:46 pm »
There are only like 4 known sizeable chunks of CI type meteorites--their first choice. Probably too rare for destructive testing. However, last I heard they have given up on CI asteroids because they are too rare. So second choice is CM meteorites. Problem is the mix of chemicals is such that upon heating, all sorts of compounds are formed except water. There was a thread a while back where a guy who seemed to know what he was talking about pointed this fact out.

Still, if I was running an asteroid mining company I'd want to try it with all different kinds of meteorites I could before I got too far along.

Or at least try to make an analog mixture with the right minerals.

Quote
Quote
ppt = parts per thousand

It is ambiguous; ppt = part per trillion is also used, and it's what I immediately read it as when you used it. Different fields though, I think - for salinity of water ppt = part per thousand is normal.

;) Well, since we are talking mining, I guess I should use "g/t" = grams per tonne of ore, or since we are talking parts per thousand, I guess you could write "kg/t"....
« Last Edit: 02/11/2014 10:49 am by Warren Platts »
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Offline aero

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Re: Mining lunar ice
« Reply #251 on: 02/09/2014 10:05 pm »
Actually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $.
Retired, working interesting problems

Offline Warren Platts

Re: Mining lunar ice
« Reply #252 on: 02/11/2014 11:01 am »
Actually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $.

??? "Parts per ton"? I don't understand. What are the parts?
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline aero

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Re: Mining lunar ice
« Reply #253 on: 02/11/2014 03:02 pm »
Actually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $.

??? "Parts per ton"? I don't understand. What are the parts?

Truth is, I've used parts per ton in my prospectors club to describe concentrates from placer mining. Concentrates are what is captured by the sluice. Its mostly black (iron) sand with some gold flakes, maybe a small nugget if you're lucky. The parts refer to the gold and convert to grams (changing to metric) at 1 mg/tonne.

Placer mining is probably not something that will be done on the Moon. It needs water.
Retired, working interesting problems

Offline Warren Platts

Re: Mining lunar ice
« Reply #254 on: 02/11/2014 03:27 pm »
Actually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $.

??? "Parts per ton"? I don't understand. What are the parts?

Truth is, I've used parts per ton in my prospectors club to describe concentrates from placer mining. Concentrates are what is captured by the sluice. Its mostly black (iron) sand with some gold flakes, maybe a small nugget if you're lucky. The parts refer to the gold and convert to grams (changing to metric) at 1 mg/tonne.

Oh OK, so its a measure of the concentration of "colors". mg/tonne is equivalent to ppb--going to have to move a lot of dirt to make any money!

Quote
Placer mining is probably not something that will be done on the Moon. It needs water.

Not necessarily. There IS water on the Moon that is happily collocated with purported gold placer deposits. Alternatively, one can use electrostatic separators as a waterless means to separate out gold from placer deposits. Attached is Edison's original electrostatic separator originally planned for use with New Mexico desert paleoplacers.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Robert Thompson

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Re: Mining lunar ice
« Reply #255 on: 02/11/2014 08:20 pm »
An upper limit for ice in Shackleton crater as revealed by LRO Mini-RF orbital radar (Thomson, 2012)
GEOPHYSICAL RESEARCH LETTERS, VOL. 39
http://adsabs.harvard.edu/abs/2012GeoRL..3914201T (paywall)
"Modeling results of ice diffusion in regolith suggest that diurnal temperature oscillations, such as those typical of permanently shaded regions adjacent to occasionally sunlit areas, can actually enhance the accumulation of ice within the uppermost meter of the surface [Schorghofer and Taylor, 2007]. In either case, the Mini-RF measurements place an upper bound on the ice content of the uppermost meter of regolith with Shackleton of 5–10 wt% H2O ice. This finding is consistent with slight albedo enhancements observed in Shackleton at optical wavelengths (430–850 nm) as measured with scattered light [Haruyama et al., 2008] and at far ultraviolet wavelengths (155–190 nm) as measured by Lyman Alpha Mapping Project (LAMP) [Gladstone et al., 2012], indicating a surface exposure of at most a few percent of high albedo material (e.g., water-ice) mixed with typical highland material."

Subsurface migration of H2O at lunar cold traps (Schorghofer, 2007)
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112
http://www.ifa.hawaii.edu/~norb1/Papers/2007-coldtrap.pdf
Check top and bottom panels of Figure 6.  According to this computer model, ~115 Kelvin is where you get the most density of subsurface water, in this case about 1 gram of water per meter squared (at the top of the volume or column), and at a mean depth of what is probably tens of meters.
This computer modeling finds "a few hundred ppm" of water [paragraph 62], {useless?} but it outlines useful mechanisms for subsurface accumulation. And it allows that these processes act outside of the crater PSRs, in areas that are glancingly or occasionally lit that surround the PSRs.

Offline Robert Thompson

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Re: Mining lunar ice
« Reply #256 on: 02/11/2014 08:44 pm »
NAIC presentations bearing on lunar/polar.

David Wettergreen, Carnegie Mellon University, 2013 Phase II Fellow
Nomadic Exploration: Following routes of solar sustenance and temperate climate
Basically send a rover that intelligently sails/circumnavigates around a crater rim, lunar day after lunar day, with a balance of solar power and batteries. Low hanging.

William Whittaker, Astrobotic Technology, Inc., 2012 Phase II Fellow
Cavehopping Exploration of Planetary Skylights and Tunnels
Prospects for sending rovers down into skylights.

Berok Khoshnevis, University of Southern California, 2012 Phase II Fellow
ISRU-Based Robotic Construction Technologies for Lunar and Martian Infrastructures
Use NASA ATHLETE as 3D printer of lunar regolith mix to build large structures.

Adrian Stoica, NASA Jet Propulsion Laboratory, 2013 Phase I Fellow
Transformers For Extreme Environments
Use self-deploying heliostats to beam solar power to a mobile receiving rover.

http://www.livestream.com/niac2014/folder?utm_source=lsplayer&utm_medium=ui-more-videos&utm_campaign=niac2014&utm_content=niac2014

See also: John Bradford, SpaceWorks Engineering, 2013 Phase I Fellow
Torpor Inducing Transfer Habitat For Human Stasis To Mars

Offline Warren Platts

Re: Mining lunar ice
« Reply #257 on: 02/12/2014 01:55 am »
An upper limit for ice in Shackleton crater as revealed by LRO Mini-RF orbital radar (Thomson, 2012)
GEOPHYSICAL RESEARCH LETTERS, VOL. 39
http://adsabs.harvard.edu/abs/2012GeoRL..3914201T (paywall)

Found a free version. 5-10% is consistent with LCROSS, and these results wouldn't apply to the northern anomalous craters like Whipple and Rozhdestvensky N.
« Last Edit: 02/12/2014 01:57 am by Warren Platts »
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline gbaikie

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Re: Mining lunar ice
« Reply #258 on: 02/12/2014 04:11 am »
An upper limit for ice in Shackleton crater as revealed by LRO Mini-RF orbital radar (Thomson, 2012)
GEOPHYSICAL RESEARCH LETTERS, VOL. 39
http://adsabs.harvard.edu/abs/2012GeoRL..3914201T (paywall)

Found a free version. 5-10% is consistent with LCROSS, and these results wouldn't apply to the northern anomalous craters like Whipple and Rozhdestvensky N.

I like free versions.
"However, the results do not rule out a modest ice contribution, and an upper limit of 5–
10 wt% H2O ice (up to 30 vol.%) present in the uppermost meter of regolith is also consistent with the observations."
30% per volume would be nice.
"Near-infrared reflectance measurements from LOLA also indicate a slight brightening
within Shackleton due to either mass wasting or possibly up to 20% water ice frost in the uppermost nm [Zuber et al., 2012]."
A nm would be near useless, but if indicates such high concentration in top few centimeters that could better for mining as compared to 30 vol.% in a meter depth.

"Radar is an optimal instrument for detecting thick deposits of water-ice for three reasons...."
....
"The fundamental conclusions made with high resolution, ground based radar of Shackleton remain unaltered – that no large-scale, meters thick ice deposits are evident within the crater."

So no killer ice rinks in Shackleton- at least at the surface.
Imagine impacting a lunar surface and just getting H20 as the plume. :)  Probably the case with all surfaces on the Moon. Probably the case with Mercury also, though it's thought there could 100 times more water at Mercury's poles.

So if there was 1 cm of water in top 5 cm of lunar regolith, that 10 kg of water per square meter. That is somewhat like moist dirt in your backyard. And 100 by 100 meters area yields 100 tons of water.
100 tons per year is good enough to open the space frontier.
Or about 1 ton water per day, or about 30 foot square per day.
Such surface mining could favor using robotic or even toy like vehicles. Or astronaut with a broom and large dust pan:)

Offline TrevorMonty

Re: Mining lunar ice
« Reply #259 on: 02/12/2014 08:17 am »
Mining shallow depressions with lower concentrations of ice eg <1% which can be accessed easily from nearby sunlight base, may prove a better option initially than trying mine a 4.5Km deep crater with higher concentrations of ice eg 5-10%.

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