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Lunar ISRU

Posted by: Ekkehard Augustin - Tue Mar 07, 2006 12:01 pm
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Lunar ISRU 
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Post Lunar ISRU   Posted on: Tue Mar 07, 2006 12:01 pm
I could have posted this to the lunar-dust-thread somehow or I could have initiated a special thread but think that a more general topic is much better.

The article "Moon Water: A Trickle of Data and a Flood of Questions" ( www.space.com/scienceastronomy/060306_lunar_ice.html ) is streesing a bit the supposed lunar ressources of water.

There may be water on the Moon but the amounts might be insufficient - or there might be nearly no water on the Moon or it might be very hard to access.

But the article is sounding to me as if hydrogen wouldn't be that problem.

If the hydrogen really isn't a problem but lunar water is then I am wondering why not creating the required water for drinking etc. by combining the hydrogen with oxygen which is intended to be got out of the lunar dust via the technology to be developed under a Centennial Challenges contest?



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Post    Posted on: Tue Mar 07, 2006 5:47 pm
because to get any amount of water takes a LOT of gaseous hydrogen and oxygen. And the combination process is the same process used by the space shuttle main engines - i.e., very combustive. although I suppose the excess heat could be used for other purposes. The result of the chemical process is not water but steam + heat.

I guess it could be done, but it seems a very inefficient process.


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Post    Posted on: Wed Mar 08, 2006 10:07 am
I already have thought about that also - but there is at least one argument why the amounts of gaseous oxygen at least can't be the problem: There is the Centennial Challenges competition for the technology to extract oxygen out of the lunar Regolith. This technology NASA explicitly intends to use to get oxygen for breathing - as air and atmosphere inside a lunar station.

So if it is possible to get enough oxygen out of the lunar Regolith for breathing then it should be possible to get enough for the production of water.

The production of water not necessaryly will be as explosive and combustive as in the SSMEs. The amounts of hydrogen and oxygen can be controlled and brought together in such limited amounts that no human, no station and no production equipment is threatened to be destroyed.

During the period of the first amounts of water are available this way water could be carried from Earth and or the raditaion and the solar wind could be used to crack other chemicals into water and other chemicals. Even chemicals created as waste at the Moon could be used to do so perhaps.



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Post    Posted on: Wed Mar 08, 2006 1:14 pm
Hmm.. well, it could be. Although it seems to me that production of water directly from other chemicals is easier than producing H2 and O2 and combining. My initial post was mostly a knee-jerk reaction . :)

I'll need to do some research to figure out what actually is needed.


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Post    Posted on: Wed Mar 08, 2006 7:38 pm
I would think it would be very easy to combine extracted oxygen and hydrogen gas to make water. In fact, if both are being extracted from the same regolith and at high temperature (as is proposed for most of the oxygen extraction methods), it would be almost impossible to prevent them from reacting and making water, or rather steam. The exothermic nature of the reaction is not a big problem in my mind. You would basically have a torch that gives off water vapor as its only combustion product. The heat generated could be used to power the extraction of more oxygen and hydrogen, which does required a lot of heat.

The real problem is how much hydrogen is there, really. I have already posted in another thread the hydrogen content measured in various Apollo samples. Oxygen makes up 45% of those samples but hydrogen is only 0.006%. There is more at the poles but the measurements do not say, quantitatively, how much more. It could be anything from massive ice deposits to tiny amounts of solar wind hydrogen trapped in the regolith.


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Post    Posted on: Mon Jul 30, 2007 10:38 am
The article "Lunar Flash Mystery Solved: Moon Just Passing Gas" ( www.space.com/scienceastronomy/070730_gassy_moon.html ) suggests that H2O may be outgasing sometimes at the craters Aristarchus , Plato, Kepler, Copernicus, Tycho and Grimaldi.

Perhaps more locations might be added later. If really water is outgasing among other gases then this would mean that it is interesting to do some exploration there and harvest the ressources of them remaining.

Of course Shackleton Crater Company will mine for water, hydrogen, oxygen, methane etc. at Shackleton carter but once they have a base there they could fly from that crater to the others by vehicles under development at present (teams competing for the Lunar Lander Challenge for example) that could be improved and enlarged regarding capacity of distance and payload.

Doing so they could install mining equipment there after sending exploration equipment and having detected ressources successfully.

What about it?



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Post    Posted on: Mon Aug 06, 2007 11:16 am
Hiya guys, I was reading about fuel cells, and it said that water was also a byproduct. So, use solar power (record efficency is up to 40%) to extract the component gases, whack them through a fuel cell to produce more power, and get water to drink. They run warm, so that could by used somehow, but there is no combustion, so it's safe.

Actually, would we have to add various minerals to the water to make it more healthy?

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Post    Posted on: Mon Aug 06, 2007 12:47 pm
Hello, Sean Girling,

regarding lunar water for drinking I think that minerals nonetheless will have to be carried to the Moon because all those minerals the formation of requires water won't exist there. I don't know if destilled water is unhealthy but I suppose this not to be the case but may be that such water isn't usefull except for helping to eat food.

Perhaps this is a question for the thread about the food-problem too.

Regarding fuel cells the point seems to be that they require oxygen and hydrogen. So they depend on the question if there is hydrogen on the monn at all. If it is there then no problem - lunar water might be cracked by solar power.

If there is lunar water but inside the Moon only and to be released by outgasing or mining gaseous water then the interesting question is how to do that best.

To wait and look for outgasings will be the wrong way - noone knows where and when the next outgasing will take place and the water outgasing will have gone when explorers and miners arrive at the location of such an event.

So the lunar surface should be investigated for subsurface caves for example. Such caves next need to be secured somehow against damage and destruction. They must be opened or accessed to safely and using pipelines to get catch the gases they might contain.

Could explorating satellites in lunar orbits with safety of scientifical degree detect geological structure surely formed by or during outgasings or resulting from Moonquakes? If yes then this could help or asist later direct local exploration and mining.

What about that?



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Post    Posted on: Mon Aug 06, 2007 1:15 pm
I doubt we'll find many caves on the moon. It's surface has been smashed and pounded by meterites for so long, I expect it to be pretty solid to some depth, but I'm no lunar geologist.

I can't see us finding an area that is both useful for solar power, and also has water. One precludes the other. So we're going to end up having to make water, if we're there long enough. The other alternative will be to keep recycling and resupplying.

Here is an interesting link about the extraction of oxygen from the lunar surface.
http://www.asi.org/adb/04/03/10/04/oxyg ... ction.html

While looking for other materials on the hydrogen extraction, I came upon the following link that seems to indicate that hydrogen on the moon is rather scarce, at around 50ppm. So we might have to transport hydrogen or just accept that water is going to be an expensive process.

http://scitation.aip.org/getabs/servlet ... s&gifs=yes

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Post    Posted on: Mon Aug 06, 2007 1:49 pm
Hello, Sean Girling,

I still have to read the links you list. So I don't know yet if the second refers to hydrogen in the traces of an atmosphere or to hydrogen frozen in permanent shadows or inside the Moon.

Regarding the caves I personally have in mind small caves merely. That gases are outgasing from time to time means that there must be small caves or channels or pipes or so inside the Moon that really lead to the surface.

If now Moonquakes would have caused the outgasings the gases must have been captured in caves that had no access to the surface before the Moonquake but are opened or weakened by a Moonquake. If they are weakened only they will be broken over long times after a Moonquake.

May be that such caves are that small that even a dog or a rat can't enter or pass them. But pipelines or so may be capable of pulling all gases or else interesting gases or liquids out fo them to store them safely and thus provide them for human purposes.

What about it?



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Post    Posted on: Tue Aug 07, 2007 11:21 am
I in between have read the links.

Regarding the hydrogen-extraction-link it seems to be talking about extracting hydrogen from lunar dust, rocks etc. merely or only which Idon't have in mind up to now.

Regarding the economical feasability of extractions my pending next post for the Lunar Siyuz-thread in the Financial Barriers section might be interesting because I think I will have a short look onto the boundaries of the costs or prices of lunar hydrogen ...



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Post    Posted on: Fri Aug 10, 2007 12:34 pm
Yeah, meanwhile I've been thinking a little further myself, so prepare for a ramble. Really, if we're going to the moon, it's not just to go and show that we can, and that we can produce our own oxygen, water, rocket propellent; and that we can do it cheaply. Nope, we're going there to make money some how. So, I guess it'll be the H3 that's in abundance up there. I was reading a NewScientist article several months ago where a space scientist/economist was describing the new race to the moon. He said that if the surface of the moon were covered in gold bars, it wouldn't be economical to fetch them, however, the H3 is so lucrative, governments that can, are all thinking about trying to get it. Soooo... If money is no problem, as this would seem, then we'll be sending plenty of hardware. So it's accedemic how much power, equipment, and supplies are going to be needed. In order to support the moon base, it's going to get done. I can see many many payloads of solar farms. Many many shipments of initial consumables. Then once the base is set up, an industrial module will be dropped in. Nuke powered probably.

The upshot of my point here is this... there may well be an elegant solution to oxygen, hydrogen, methane, for air, water, rocket fuel etc; but they'll not happen for a while, for the powers that be will be looking for the quick buck. They don't want to wait to find all the cool cheap ways of doing things, no, they'll just keep resupplying the base instead.

The future will improve the self reliance, but by then, there may be a different economical situations, and the presence of a regular Lunar Earth shuttle system that competes.

Following this, I then thought about where we presently get our water from, here on Earth. Correct me if I'm wrong, but we're not making any more water really are we? Not really! So, if we have a sufficiently sized lunar complex, with a large enough biosphere, then we could support up to say ten occupants within an almost closed system, with a few resupplies every now and then. Initially, it'll be a lunar version of the ISS, that gets new mudules every now and then. One of them could well be an inflateable area, easily the size of a football field (there are some inflateable arenas, with several tennis courts inside, here in Lincolnshire England). Within this space, hydroponics could recycle water & air.

I was trying to find out how much hydrogen and oxygen are needed to make water. I was able to find that you need about 0.42kg of hydrogen for a gallon of water, so I guess you could work out the rest of the oxygen. That sounds like a lot to me.

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Post    Posted on: Tue Nov 27, 2007 12:36 pm
Under the aspect that the outgasings may mean the loss of lunar ressources into space - what about applying the idea to bake lunar dust by using microwaves?

If the regions where outgasings might occur in the future could be identified a bit more precise the most suspicious locations within these regions could be sealed by baking and installing gas collectors below the baked locations. Of course the baked layer would have to be thick.

But the method would avoid the transport of sealing materials from Earth.

What about it?



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Post    Posted on: Wed Nov 28, 2007 6:34 pm
Pure H2O is perfectly fine to drink. Even D2O can safely be consumed in large quantities, but it can't fully replace H2O.

As long as we can find or bring enough hydrogen, combining it into water should be a simple matter. Not only can fuel cells combine it just fine, but internal combustion engines (regular car engines, modified to run on hydrogen) can too.

If we don't find enough hydrogen on the moon, I think in the long run it will be cheaper to harvest it from nearby asteroids than to bring it from Earth. Provided, of course, that we can create rocket fuel from resources we find on the moon.


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Post    Posted on: Thu Nov 29, 2007 3:34 am
Hi,
The lunar samples that were collected by the apollo program show only two types of regolith both rich in oxygen but hydrogen and helium present only in trace amounts. The interesting thing is that across the moon the regolith seems to be very uniform. Just two types.
Where then to find hydrogen or water?
There is a theory that Hydrogen or water might have accumulated at the poles in craters that are permanently kept in the dark.
Signals suggesting this is so have been collected. However this may indicate trace amounts only.
A slick, maybe a molecule or two thick .
Or it may indicate decent deposits of water or hydrogen.

We don't know yet.

Even if the lunar poles turn out not to be a good source of water this doesn't mean that there is no water (or hydrogen ) on the moon.

When a meteor (or comet) hits the moon then it may leave an ore body buried under the centre of it's crater. Its these ore bodies that may be rich in chemicals different to the covering regolith.

If it's an iron rich meteor you would expect to find an iron rich mass under the floor of the crater.
If its a carbonaceous meteor...

To do any serious building on the moon ways must be found to map these hidden ore bodies. Once we know what's there we'll know where to build and where to mine.

Till then just take along your own hydrogen, bake the oxygen out of the regolith with a solar furnace and burn the hydrogen to get water.

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