Author Topic: Lunar Water Exploitation  (Read 2647 times)

Offline sanman

  • Senior Member
  • *****
  • Posts: 3508
  • Liked: 401
  • Likes Given: 1
Lunar Water Exploitation
« on: 09/17/2016 09:27 AM »
With all the bigger new rockets on the drawing boards, it seems likely that humanity may make a significant return to the Moon before 2030, hopefully as part of a sustainable presence. This then brings forth the issue of water resources on the Moon and their utilization/exploitation.

Beyond the obvious use for rocket fuel and drinking water, will we see water used for large-scale agriculture on the Moon? Could the Moon with its abundant real estate and solar energy become a breadbasket for the teeming masses of Earth? (Then we can stop clear-cutting on Earth, and save our own homeworld)

If various entities are operating side-by-side on the Moon -- private US operators, China, Russia, ESA -- then how will water resources be allocated and managed? Will it be first-come-first-serve? Is there enough for everyone? I'm assuming there'll be no need to resort to force to prevent someone from seizing something you've claimed. The Moon Treaty seems to be vaguely similar to the Antarctic treaty, although nobody seems to have really ratified it to give it teeth.

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

By what date can we expect a thorough and comprehensive mapping of ice deposits on the Moon?

How exactly will lunar ice be gathered up from where it exists, and brought to human habitations for use? Will there be pipelines stretching to craters within whose shadow ice may exist? Or will there be robot tanker trucks transporting the water back to base?
Would habitations be set up purely on the basis of close proximity to lunar ice deposits?

Are there any other sources of lunar water that may be exploitable, like underground water?

http://www.space.com/22553-moon-water-mystery-source.html


As lunar water exploitation increases in capacity, what are the progression of further uses for the water?

I'm imagining that if I were a lunar space tourist on a 2-week stay, I'd love for there to be a large artificial wave pool on the Moon, because outdoor excursions into the barren gravelly landscape are going to get old really quick.
(Now that I think about it, would the Earth's pull on the Moon result in much higher tides for a sufficiently large body of lunar water? I wonder how big such a body of water would have to be to give some good surfing in the lower lunar gravity? Can anyone calculate this?)


EDIT: Actually, wait, if the Moon is tidally locked to the Earth, and the same side of the Moon always faces the Earth, then I guess the Moon can't really have any tides, can it? But that might also be a reason for any underground lunar water to be more likely to be found on the nearer side of the Moon, wouldn't it?
« Last Edit: 09/17/2016 09:37 AM by sanman »

Offline high road

  • Full Member
  • ****
  • Posts: 624
  • Europe
  • Liked: 163
  • Likes Given: 37
Re: Lunar Water Exploitation
« Reply #1 on: 09/17/2016 12:57 PM »

Large scale agriculture for transport back to Earth --> nope. You have to launch all nutrients for the plants from Earth. Unless that plant you're massively harvesting happens to be illegal on Earth, in which case good luck bringing it here unnoticed. Also, the world isn't running out of arable land, but out of cheaply arable land. Irrigating the deserts requires only to purify sea water and either pumping it hundreds of meters uphill. Alternatively, floating barges could be designed to house farms. All these ideas are far cheaper than anything produced on the moon. No location in space, no matter how fertile, would be cheaply arable land unless launching a rocket costs as much as driving a truck of the same capacity.

A pipeline would only be used if there is a massive amount of water that needs transportation. Assuming water would be recycled at near 100%, the only activity that would require so much water is massive production of materials that contain hydrogen (or lose the hydrogen to space during production), or fuel for spacecraft.

People on the moon will want to limit the amount of time they will want to be outside. Transporting water and/or power should be easier than whatever activity they are there for in the first place. So unless the human presence is there for the water itself, it would not have to be close to water. That means only three types of activities would ever be close to water: early settlements that still need to find out how to maintain a base on the moon, the aforementioned lunar fuel extraction plant, and research/production using the properties of the location where the water is, eternal sunshine and eternal darkness.

As for all the rest: how much there is, how it will be divided, etc, we'll have to see when we get there. Depends largely on what we find that makes it worth to fight over it.

Offline Lunadyne

  • Member
  • Posts: 6
  • EML-1. the crossroads of cislunar space
  • Liked: 3
  • Likes Given: 0
Re: Lunar Water Exploitation
« Reply #2 on: 09/17/2016 05:39 PM »
Agriculture on the Moon is a fascinating concept, and one that has appeal far beyond the usual space-interest markets.

There hasn't been a whole lot of research done on growing plants on the Moon.  Drs. Walkinshaw et al got good results when they were testing the regolith for toxicity by seeing if plants would grow in it.  Once it was determined to be non-toxic in that regard the growth experiments stopped.  There was a book published in the 1980s on Lunar Base Agriculture, but all of the authors noted that regolith simulant was a poor substitute for the real thing.  I've seen many fruitless attempts to grow plants in regolith simulant, even from folks like Solar System Ambassadors.

The key seems to be the trace elements distributed throughout the Lunar regolith by aeons of impacts from asteroids.  The components of the asteroid vaporize during the impact, and settle as a blanket over the area surrounding the new crater.  This ongoing process mixes and stirs the stuff into and throughout the soil.  This is something that absolutely cannot be replicated in regolith simulant (without spending lots of money trying to get similar results).  NASA of course is carefully guarding their paltry stock of Lunar samples, and given the destructive nature to the regolith that would be entailed by plant growth they are leery of giving out samples except for really good, solid science.

That being said, there's also the concept of terroir, wherein the taste of a foodstuff is a function of its growing environment, including nutrients available to the roots.  This concept is both a risk and an opportunity for Lunar agriculture, as it may be that foodstuffs grown in Lunar soil will have a different savor or tang as a result of the abundance of trace elements in the regolith, that on Earth have been sucked out of the soil by centuries and millenia of industrial farming.  It's why we use fertilizer.

To be fair, high road is right that nutrients would have to be added to the Lunar dirt, as was the case with the 1970s Apollo experiments, for plant growth.  However, the supply requirements from Earth might be offset in part by use of local materials.  If we're doing the Lunar shake and bake of the soil during processing, whereby you agitate the regolith and heat it up to about 800 degrees celsius to drive off the Solar Wind Implanted Elements (SWIEs) before sending the material off to be cracked for oxygen (about 40-45% of the Moon by mass) or melted for metals.  The SWIEs contain all of the CHONs, though not in particularly large quantities.  The SWIEs are also where the Helium-3 will be coming from.

So use of water for agriculture is likely a later step in the process of Lunar ISRU, but I do think there is potential there for new flavors and tastes that people will find appealing.  Early product is likely to be used at the Lunar base, eventually growing to accommodate other facilities on the Lunar surface and any EML-1 facility.  Further down the road, crews stockpiling resources at EML-1 for trips to the asteroids, and other locales will serve as a market.  LEO stations might appreciate a load of fresh fruit.  Though I have to agree with high road that illegal crops like LunajuanaŠ (for which I've already claimed the copyright) would likely be the only ones to have profit margins (at least in the near term) to merit shipment all the way to Earth.

Once we're building out lava tubes then we can begin talking about the larger bodies of water of which you speak.  One concern raised in Neil Ruzic's 'Where the Winds Sleep' is that the surface tension of water in the lower Lunar gravity would create films of water that would have to be wiped off the face before breathing after surfacing, or risk lungs full of water and air.  Given the recent studies on lava tubes showing that some could be large enough to house the city of Philadelphia, with room to spare, we probably could have waterparks and wave pools on the Moon in the future.

Ultimately, though, we want to be getting our water from the asteroids for use in cislunar space, and so early use of Lunar water as propellant, gases, and good ol' bathwater should probably be focused to that end.

Offline gbaikie

  • Full Member
  • ****
  • Posts: 1628
  • Liked: 48
  • Likes Given: 5
Re: Lunar Water Exploitation
« Reply #3 on: 09/18/2016 07:03 AM »
With all the bigger new rockets on the drawing boards, it seems likely that humanity may make a significant return to the Moon before 2030, hopefully as part of a sustainable presence. This then brings forth the issue of water resources on the Moon and their utilization/exploitation.

Beyond the obvious use for rocket fuel and drinking water, will we see water used for large-scale agriculture on the Moon? Could the Moon with its abundant real estate and solar energy become a breadbasket for the teeming masses of Earth? (Then we can stop clear-cutting on Earth, and save our own homeworld)
The Moon is probably not a good place to grow crops, whereas Mars could be a good place to grow crops,
but growing food for Earthlings seems unlikely within a century. But Earthlings could live in LEO, and getting Mars food to LEO maybe something possible within a century.
The Moon could a place one builds housing and other infrastructure for LEO and other earth orbits.
Generally the Moon is good place for mining rather than farming, though on could grow food or plants on the Moon- but probably mostly to convert CO2 made by human or other processes which make CO2.
Whether Mars is good place to grow crops will probably depend upon a large quantity of available water- billion of tons and comparable cost of water on Mars as the cost of water on Earth.
Quote
If various entities are operating side-by-side on the Moon -- private US operators, China, Russia, ESA -- then how will water resources be allocated and managed? Will it be first-come-first-serve? Is there enough for everyone? I'm assuming there'll be no need to resort to force to prevent someone from seizing something you've claimed. The Moon Treaty seems to be vaguely similar to the Antarctic treaty, although nobody seems to have really ratified it to give it teeth.
https://en.wikipedia.org/wiki/Moon_Treaty
The Moon has billions of tons of H2 and zillions of ton of oxygen chemically bonded to silicone and metals.
Getting the H2 and O2 is mostly problem of cost of electrical power.
It terms of water not chemically bond, the moon probably has +10 billion tons of water, but in terms of near term minable water, the amount water might somewhere around millions of tons.
What will happen is that the cost of water will highest price and cost in the near term. Ie, water could within first decade be about $500 per kg, but as water is mined the cost of getting to the moon will lower and the cost of lunar water and most importantly lunar electrical power will lower. Which roughly means what water is not minable now, will in the future become minable. Or right now it's millions of tons [at most] but in future there will be billions of tons minable.
I would say that within 10 years of beginning of commercial lunar water, one will have commercial lunar iron mining. Lunar iron mining will make a surplus of O2. To turn iron to steel one needs carbon. But structurally
iron is not too bad to use in low gravity moon. But if making a lot of steel, one going to need a lot of carbon.

Quote
By what date can we expect a thorough and comprehensive mapping of ice deposits on the Moon?
That's the question.
Quote
How exactly will lunar ice be gathered up from where it exists, and brought to human habitations for use? Will there be pipelines stretching to craters within whose shadow ice may exist? Or will there be robot tanker trucks transporting the water back to base?
Would habitations be set up purely on the basis of close proximity to lunar ice deposits?
Yes. And one should mine lunar water before having lunar bases.
Quote
Are there any other sources of lunar water that may be exploitable, like underground water?

http://www.space.com/22553-moon-water-mystery-source.html
A thread on topic:
http://forum.nasaspaceflight.com/index.php?topic=40346.0

Quote
As lunar water exploitation increases in capacity, what are the progression of further uses for the water?

I'm imagining that if I were a lunar space tourist on a 2-week stay, I'd love for there to be a large artificial wave pool on the Moon, because outdoor excursions into the barren gravelly landscape are going to get old really quick.
(Now that I think about it, would the Earth's pull on the Moon result in much higher tides for a sufficiently large body of lunar water? I wonder how big such a body of water would have to be to give some good surfing in the lower lunar gravity? Can anyone calculate this?)
One make a dome which is strong enough to withstand less than 2 psi. Water at 2 psi boils at 52.2 C
So with less than 2 psi one could have water as warm as 40 C [104 F]. And at depth one gets more pressure
from the water. One earth one get 14.7 psi [1 atm] at 10 meters depth. With moon is would be 1/6th the pressure [14.7 divided by 6 is 2.45 psi] so 10 meter under water you don't need a pressure suit- just need scuba or simply holding your breath. Also 100 meters is 24.5 psi- less pressure than 10 meters under water on Earth. So one dive deeper in water the Moon.

Quote
EDIT: Actually, wait, if the Moon is tidally locked to the Earth, and the same side of the Moon always faces the Earth, then I guess the Moon can't really have any tides, can it? But that might also be a reason for any underground lunar water to be more likely to be found on the nearer side of the Moon, wouldn't it?
On Earth the sun has tidal force, and one also get tidal force from the Sun on the Moon.

Offline Phil Stooke

  • Full Member
  • ***
  • Posts: 315
  • Canada
  • Liked: 182
  • Likes Given: 0
Re: Lunar Water Exploitation
« Reply #4 on: 12/25/2016 11:45 PM »
The lunar orbit is elliptical, so the Moon's distance from Earth varies during the monthly orbit.  Therefore the Earth's gravitational effect on the Moon (gravity gradient across the diameter of the Moon) varies during the month.  That's the tidal effect we are talking about here - the Moon gets stretched a bit along the Moon to Earth vector, but the amount of stretching varies during the month.  It's not like the Earth's case, where the planet rotates through the tidal bulge on a daily basis.

Offline wannamoonbase

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 2573
  • Denver, CO
    • U.S. Metric Association
  • Liked: 489
  • Likes Given: 819
Re: Lunar Water Exploitation
« Reply #5 on: 01/04/2017 04:10 PM »
I think growing plants/food on the moon will be done for life support reasons using hydroponics.

One of the biggest learning objectives from lunar living would be developing, testing and refining a closed loop life support system.  Using plants to scrub CO2, produce oxygen and provide food for the crew.

Hydroponics would give the best control and use the least amount of space and water as well.  Especially in what will initially be tight quarters.

Using water in a closed loop system with a O2/H2 fuel cell for Lunar nights or peak loads could be very beneficial as well.
I know they don't need it, but Crossfeed would be super cool.

Offline TrevorMonty

Re: Lunar Water Exploitation
« Reply #6 on: 03/22/2017 06:09 AM »
When comes to propellant production energy is biggest component which make sense as fuel stores potential energy and engines convert it to kinetic energy or thrust. A rough rule of thumb for water to LOX/LH production is 6.7kW/hr per kg of fuel. This covers electrolysis  (biggest energy consumer) and refrigeration. For lunar polar facility with 80% sunlight a sun track 1kw solar panel would produce 7MW/hr, enough to produce 1t  of LOX/LH. Don't know how much energy is required to extract water from craters, so going to assume 300kw/hr is enough combined with surplus heat from LOX/LH production.

For space based solar arrays 100W/kg is good figure, this covers solar panels, cabling, power converters, heatsinks. For lunar sun tracking array mounted on stand I'm going to assume 50W/kg. A 100kw 2t solar array would be enough to produce 100t a year. Don't know production and mining equipment weight..

Based on my very rough mass estimates 25t on lunar surface should produce a few hundred tons of LOX/LH. This would only be 5 launchers of New Glenn with a Blue Lander.

At some stage all LEO payloads would be delivered to lunar surface using lunar fuel plus some LH from earth, allowing even more production for lot lower investment than for first 25t.
« Last Edit: 03/22/2017 06:11 AM by TrevorMonty »

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 11346
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 2470
  • Likes Given: 355
Re: Lunar Water Exploitation
« Reply #7 on: 03/22/2017 06:25 AM »
When comes to propellant production energy is biggest component which make sense as fuel stores potential energy and engines convert it to kinetic energy or thrust. A rough rule of thumb for water to LOX/LH production is 6.7kW/hr per kg of fuel. This covers electrolysis  (biggest energy consumer) and refrigeration. For lunar polar facility with 80% sunlight a sun track 1kw solar panel would produce 7MW/hr, enough to produce 1t  of LOX/LH. Don't know how much energy is required to extract water from craters, so going to assume 300kw/hr is enough combined with surplus heat from LOX/LH production.

A kW/hr is Joules per second per second. That is not the same as energy which is kWh (Joules per second times second = Joules). So if water requires 6.7 kWh/kg (ideal is 3.73 kWh/kg) then for 1000 kg, that is 6700 kWh. At 80% sun that is equivalent to 6700/0.8 = 8375 kWh. That means a 1 kW panel would need 8375 hours or 349 days to make to required amount of energy! You're going to need a much bigger solar array.
« Last Edit: 03/22/2017 06:45 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline TrevorMonty

Re: Lunar Water Exploitation
« Reply #8 on: 03/22/2017 08:31 AM »
When comes to propellant production energy is biggest component which make sense as fuel stores potential energy and engines convert it to kinetic energy or thrust. A rough rule of thumb for water to LOX/LH production is 6.7kW/hr per kg of fuel. This covers electrolysis  (biggest energy consumer) and refrigeration. For lunar polar facility with 80% sunlight a sun track 1kw solar panel would produce 7MW/hr, enough to produce 1t  of LOX/LH. Don't know how much energy is required to extract water from craters, so going to assume 300kw/hr is enough combined with surplus heat from LOX/LH production.

A kW/hr is Joules per second per second. That is not the same as energy which is kWh (Joules per second times second = Joules). So if water requires 6.7 kWh/kg (ideal is 3.73 kWh/kg) then for 1000 kg, that is 6700 kWh. At 80% sun that is equivalent to 6700/0.8 = 8375 kWh. That means a 1 kW panel would need 8375 hours or 349 days to make to required amount of energy! You're going to need a much bigger solar array.

You just proved what I said was correct that 1kw panel can produce enough energy over a year for 1ton.
Not sure where you think my calculations are wrong.

Thanks for correction on kW hour.
« Last Edit: 03/22/2017 08:35 AM by TrevorMonty »

Offline TrevorMonty

Re: Lunar Water Exploitation
« Reply #9 on: 03/30/2017 08:13 PM »
Jeff Foust (@jeff_foust) tweeted at 7:11 AM on Fri, Mar 31, 2017:
Gerst: we want to understand if there are resources on the Moon we can use; could potentially change our architectures going forward.


Hopefully this is indication that NASA will do series of robotic missions to poles to survey ice deposits. These surveys are critical for any company considering doing water extraction.


Online envy887

  • Senior Member
  • *****
  • Posts: 2158
  • Liked: 945
  • Likes Given: 613
Re: Lunar Water Exploitation
« Reply #10 on: 04/04/2017 08:35 PM »
When comes to propellant production energy is biggest component which make sense as fuel stores potential energy and engines convert it to kinetic energy or thrust. A rough rule of thumb for water to LOX/LH production is 6.7kW/hr per kg of fuel. This covers electrolysis  (biggest energy consumer) and refrigeration. For lunar polar facility with 80% sunlight a sun track 1kw solar panel would produce 7MW/hr, enough to produce 1t  of LOX/LH. Don't know how much energy is required to extract water from craters, so going to assume 300kw/hr is enough combined with surplus heat from LOX/LH production.

A kW/hr is Joules per second per second. That is not the same as energy which is kWh (Joules per second times second = Joules). So if water requires 6.7 kWh/kg (ideal is 3.73 kWh/kg) then for 1000 kg, that is 6700 kWh. At 80% sun that is equivalent to 6700/0.8 = 8375 kWh. That means a 1 kW panel would need 8375 hours or 349 days to make to required amount of energy! You're going to need a much bigger solar array.

You just proved what I said was correct that 1kw panel can produce enough energy over a year for 1ton.
Not sure where you think my calculations are wrong.

Thanks for correction on kW hour.
You did not show "per year" anywhere in your first post, just "per hour" - slight difference in time scales :D

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 11346
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 2470
  • Likes Given: 355
Re: Lunar Water Exploitation
« Reply #11 on: 04/05/2017 12:26 PM »
You did not show "per year" anywhere in your first post, just "per hour" - slight difference in time scales :D

Actually, he does in the second paragraph.

"A 100kw 2t solar array would be enough to produce 100t a year."
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline TrevorMonty

Re: Lunar Water Exploitation
« Reply #12 on: 07/06/2017 02:35 AM »
ESA finally allocating serious money towards their moon village. ISRU is first step. Even better using commercial companies.

Angeliki (@Capoglou) tweeted at 11:51 PM on Tue, Jul 04, 2017:
Opportunity: Produce drinkable water & breathable oxygen on the Moon by 2025 with an ESA investment not exceeding 300M #MoonVillage #ESARIS https://t.co/fo1wFuJ0YV
(https://twitter.com/Capoglou/status/882205271174651904?s=03)

Offline DougSpace

  • Member
  • Posts: 27
  • Liked: 1
  • Likes Given: 0
Re: Lunar Water Exploitation
« Reply #13 on: 07/16/2017 05:26 PM »
Lotsa questions...

> water used for large-scale agriculture

Only on the scale needed for habitants on the Moon.  Shipping food to Earth is ridiculous.  LCROSS showed organics which could be used to replace recycling losses.

> various entities are operating side-by-side...how will water resources be allocated

The closer we get to this point the more willing countries will negotiate this issue.  Probably, land usage will determine a modest non-interference zone.  Companies from various countries will sell products and services to each other.  There's too much ice to worry about someone contributing long it all.

> The Moon Treaty...

...is a joke.

> By what date can we expect a thorough and comprehensive mapping of ice deposits on the Moon?

We don't need to.  The so-called Peaks of Eternal Light (PELs) is where initial operations will be set up.  So, we just need to know the concentration of ice near those points.  However, we should start development mg the landers, telerobots, and habitat before we find out this information.  We are going to the Moon regardless of the specific findings about ice.  If need be, we'll just launch multiple launchers to get to Saturn V / SLS level.

> lunar ice be gathered...and brought to human habitations

First of all, most of the ice will be harvested and processed into propellant on the floor of a permanently-shadowed crater.  Occasionally, a lander with a good amount of distilled water and organics will hop from the floor to the landing pad near the habitat.  One such payload delivery would last a recycling habitat for years.

> habitations be set up purely on the basis of close proximity to lunar ice deposits?

No, proximity to the PELs.  Volatiles can be hopped from dozens or hundreds of miles away if necessary (e.g. Cabeus).

> As lunar water exploitation increases in capacity, what are the progression of further uses for the water?

More propellant for international, suborbital exploration (e.g. 5-6 hops per week with a different country each week).  Then transport of private individuals to a growing lunar base / settlement.  The organics in the ice could be used for plant food, plastics, and other organic chemicals.

> large artificial wave pool on the Moon

Later private individuals will require amenities.  This would start with large, inflatables providing 0.8 acre coverage each so Olympic-sized swimming pools and driving ranges would be doable.

Offline TrevorMonty

Re: Lunar Water Exploitation
« Reply #14 on: 07/20/2017 10:01 AM »
Lunar hops can be expensive, depends on distance.  90degree ie pole to equator is 1.53km/s. 30degree is 1km/s.
10kms 120m/s. (Eg Crater rim to floor)

Tags: