Lunar Carbon?

John Creighton · 2005-10-15 23:31:36

Extraction of volatiles. Lunar soil heated to 1300 K releases 0.1% by weight of the following trapped volatiles: CO, CO2, N2, H2, H2O, SO2, H2S, CH4, and inert gases (He, Ar, Ne, Kr, Xe). As much as 0.5-1.5% by weight may be released upon heating to 1700 K (Phinney et al., 1977).
This is from NASA's 1980 Advanced Automation for Space Missions study, which proposes self-replicating robot factories for Luna development.
http://www.islandone.org/MMSG/aasm/AASMIndex.html

How much energy does it take to heat 1 kg of dirt to 1700 K?

noosfractal · 2005-10-16 00:56:41

How much energy does it take to heat 1 kg of dirt to 1700 K?

The AASM puts the specific heat of luna regolith at 840 J/kg, so that is something like 0.4 kWh/kg for dry roasting to 1700 K. They say that wet processes for extraction (i.e., heavy duty acids) require a lot less energy.

tSpace says 26 kWh/ton to mine lunar ice. You only need to heat the regolith to 150 K in vacuum to get the water ...

http://www.exploration.nasa.gov/documen … tSpace.pdf

The presentation above also includes a survey-backed forecast of a multi-billion dollar space tourism industry by 2025.
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John Creighton · 2005-10-23 12:16:38

How much energy does it take to heat 1 kg of dirt to 1700 K?
The AASM puts the specific heat of luna regolith at 840 J/kg, so that is something like 0.4 kWh/kg for dry roasting to 1700 K. They say that wet processes for extraction (i.e., heavy duty acids) require a lot less energy.
tSpace says 26 kWh/ton to mine lunar ice. You only need to heat the regolith to 150 K in vacuum to get the water ...
http://www.exploration.nasa.gov/documen … tSpace.pdf
The presentation above also includes a survey-backed forecast of a multi-billion dollar space tourism industry by 2025.
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I would like to look at this further to get a better idea of the costs and savings. So we should try to estimate the mass of the reactor necessary for each option and the cost necessary to ship that reactor to mars. We can look at supplying the oxygen needs for just the Lander and supplying the oxygen needs for a ship that goes between the moon and the earth. We can start with the VSE flight rates and payload estimates for a starting point. I would also like to know what level of recycling is possible in the non dryroasting methods.

BWhite · 2005-10-23 23:51:05

Extraction of volatiles. Lunar soil heated to 1300 K releases 0.1% by weight of the following trapped volatiles: CO, CO2, N2, H2, H2O, SO2, H2S, CH4, and inert gases (He, Ar, Ne, Kr, Xe). As much as 0.5-1.5% by weight may be released upon heating to 1700 K (Phinney et al., 1977).
This is from NASA's 1980 Advanced Automation for Space Missions study, which proposes self-replicating robot factories for Luna development.
http://www.islandone.org/MMSG/aasm/AASMIndex.html
How much energy does it take to heat 1 kg of dirt to 1700 K?

If you do it with sunlight the exact amounts needed are not relevant because the equipment is very cheap and the heating occurs essentially for free.

On Earth, low cost mirrors can achieve 2000 F pretty easily. Remove the atmosphere that diffuses the insolation and higher temperatures are possible.

noosfractal · 2005-10-24 03:11:15

If you do it with sunlight the exact amounts needed are not relevant because the equipment is very cheap and the heating occurs essentially for free.

Parabolic mirrors are a great idea, but they are not exactly free beer. It all comes down to kW/kg. How much processing capacity can I get for a given mass? It better be good because I'm paying $65000/kg to deliver it to the luna surface. Say I decide to spend $130m to deliver 2 tons of self-deploying parabolic mirrors and volatile capture and storage facilities to the luna equator. How many kilograms of luna regolith can I process per hour? 10? 100? 1000? It depends how big my mirrors are, how thin my mirrors are, how little deployment and supporting structure I can get away with.

An interesting part of the do-it-all-with-solar-cells approach is that instead of sending 2 tons of solar cells, it seems possible to send a 2 ton rovot with a vapor deposition chamber that can pave a square kilometer of the luna surface with solar cells instead. That's a nice power return on mass investment. It's less clear how you could do that for parabolic mirrors. The same rovot could definitely be modified make, say, a million foot-square mylar mirrors, but you've still got to arrange sets of them into a parabola and point them at the sun as well as a volatile capture unit. Robotically possible, but it seems to be a couple of orders of magnitude more complicated.

Ignoring the possibility of ISRU power bootstrap, I bet parabolic mirrors can be really competitive for thermal kW/kg - I'm not so sure about electric kW/kg, because of the added complexty of sterling engines and generators. Solar cells installed on the ISS deliver about 0.1 kW/kg. Lightweight thin-film solar cell tech is promising 1.0 kW/kg, but no-one knows how they'll stand up to the extraterrestrial environment. The nuclear tech I've seen, such as ...

http://www.sop.usra.edu/rasc-al/2004_pa … seidon.pdf

is looking at electric 0.2 kW/kg - not actually all that impressive for the political grief that you'll have to wear.

So say we've got a dozen gossamer thin parabolic mirrors delivering thermal 10 kW/kg. Now what? Does a rovot bulldoze regolith to a fixed target area? Is the mirror and capture unit mounted on a long rovot? Are there secondary mirrors that direct the energy to a moving capture device? Some sort of conveyor belt through a fixed target area?
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SpaceNut · 2005-10-24 05:57:32

Now that you have the regolith in a pile where is the chamber to allow for the gas capture? This just added to the cost for the parabolic mirrors. This degree of temperature within the chamber would melt the the windows to which the beam would be focused or aimed onto the regolith.
This means a sealed chamber and heating from within.

SpaceNut · 2005-10-24 09:07:20

Edit:
off topic moved to the correct thread:

Grypd · 2005-10-24 10:11:17

I know we have a thread but will place this here since we are discusing insitu resources.
The 1967 outer space treaty is an issue that will need resolving.
Property rights on the moon
US National Academies of Science will hold a special meeting on Wednesday to clarify the issue. Space Settlement: Homesteading on the Moon will discuss the policy implications of a lunar colony and whether privately funded missions should be allowed to play a role.
Behind the (fake) lunar title deeds for sale over the internet, there is a serious issue. The wonderfully named United Nations Office for Outer Space Affairs, which governs, well, outer space, is clear.
Its 1967 Outer Space Treaty says no nation can claim ownership of any celestial body (including the moon) and that all nations must agree to their peaceful use.
The UN says that private expeditions count as national activities and are covered by the treaty, which has been signed by all the major players. Lawyers disagreed and a second agreement - the 1979 International Moon Treaty - was drawn up to explicitly ban private ownership of lunar real estate
Is it time to have a meeting to void this law so as to allow for ownership or are there other ways to resolve this...

As stated this is one of the most important things that would allow creation of a private space industry if they thought what they found they could mine and keep and make a profit out of it. At the moment as we have said many times on this forum frankly it is not worth any private money to be spent on private missions only to service goverment exploration. Needless to say that also completely stops private money for the likes of TSTO or SSTO.

Gah I hate that Moon treaty it has sections I do approve of but they are simply a consolidation of previous space treaties and agreements. But that no private ownership of any outer space entity or terrain will keep us on this planet.

John Creighton · 2005-10-24 11:02:12

Parabolic mirrors are a great idea, but they are not exactly free beer. It all comes down to kW/kg. How much processing capacity can I get for a given mass? It better be good because I'm paying $65000/kg to deliver it to the luna surface.

Your doing great work finding out the important numbers. Once we gather enough information I am going to add a section to the new mars wiki.

An interesting part of the do-it-all-with-solar-cells approach is that instead of sending 2 tons of solar cells, it seems possible to send a 2 ton rovot with a vapor deposition chamber that can pave a square kilometer of the luna surface with solar cells instead. That's a nice power return on mass investment.

That is quite interesting. Will it work? How long will it take. What is the expected lifespan of the rover.

It's less clear how you could do that for parabolic mirrors. The same rovot could definitely be modified make, say, a million foot-square mylar mirrors, but you've still got to arrange sets of them into a parabola and point them at the sun as well as a volatile capture unit. Robotically possible, but it seems to be a couple of orders of magnitude more complicated.
Ignoring the possibility of ISRU power bootstrap, I bet parabolic mirrors can be really competitive for thermal kW/kg - I'm not so sure about electric kW/kg, because of the added complexty of sterling engines and generators. Solar cells installed on the ISS deliver about 0.1 kW/kg. Lightweight thin-film solar cell tech is promising 1.0 kW/kg, but no-one knows how they'll stand up to the extraterrestrial environment.

One thing to be careful here is where is the lunar base? If it is at the lunar polls solar celles are not going to be efficient unless they face the sun because otherwise the sun will only hit them at a grazing angle which will mean a lot less potential power per area. Solar cells are nice because we can get the needed temperatures by an electric arc. Parabolic mirrors may be more efficient but we need to consider how big a mirror we need to get the desired temperatures and if it is practical to build.

The nuclear tech I've seen, such as ...
http://www.sop.usra.edu/rasc-al/2004_pa … seidon.pdf
is looking at electric 0.2 kW/kg - not actually all that impressive for the political grief that you'll have to wear.

This is interesting. I would of thought that nuclear power would be vastly superior. I am sure we can do better and make it outperform solar but it will require a fair bit of research dollars. The big advantage of nuclear power though is there is very little to set up. And I think it can be built with less moving parts to which should make it more reliable.

noosfractal · 2005-10-24 11:41:42

Now that you have the regolith in a pile where is the chamber to allow for the gas capture? This just added to the cost for the parabolic mirrors.

I think you could have a secondary mirror to direct the beam to a mobile capture unit. You would have to be careful not to melt the capture unit though
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noosfractal · 2005-10-24 11:50:22

The 1967 outer space treaty is an issue that will need resolving.
...
Is it time to have a meeting to void this law so as to allow for ownership or are there other ways to resolve this...

As far as I can see it just says ...

Moon Treaty[/url]"]
2. The moon is not subject to national appropriation by any claim of
sovereignty, by means of use or occupation, or by any other means.

So any claim to ownership must be by an extranational entity.

Moon Treaty[/url]"]
3. Neither the surface nor the subsurface of the moon, nor any part
thereof or natural resources in place, shall become property of any
State, international intergovernmental or non-governmental organization,
national organization or non-governmental entity or of any natural
person.

Ownership by extranational entities is not forbidden and so is permitted.

I don't see the problem.
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SpaceNut · 2005-10-24 12:23:07

off topic

noosfractal · 2005-10-24 12:27:29

[ISRU solar cell manufacture] is quite interesting. Will it work?

These guys think so ...

http://www.niac.usra.edu/files/library/ … natiev.pdf

How long will it take.

It says 50-500 kW worth per year per rovot.

What is the expected lifespan of the rover.

Good question The Mars rovers are coming up on two years now.

I would of thought that nuclear power would be vastly superior. I am sure we can do better and make it outperform solar but it will require a fair bit of research dollars. The big advantage of nuclear power though is there is very little to set up. And I think it can be built with less moving parts to which should make it more reliable.

The other nice thing about nuclear, is that it doesn't care how far from the Sun it is. Closer to the Sun, I'm not sure you're going to be able to outperform thin-film solar in terms of kW/kg - fuel, containment, turbine - nuclear power is heavy.
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noosfractal · 2005-10-24 12:50:39

Extranational entity meaning ?

Entities operating in extranational realms, the rights to which have been so generously surrendered by national and international entities.
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Grypd · 2005-10-24 13:17:31

Ownership by extranational entities is not forbidden and so is permitted.
I don't see the problem.
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One point that is the Moon treaty you are phrasing and unlike the outer space treaty it is hardly been taken up. Now the outer space treaty does put limitations on us.

As Spacenut notes an extranational body must therefore be off this world and also not an organisation or goverment that is linked to one of this world. The problem for buisness and private entities are that they are citizens of countries of this world. The treaty is very specific and states that any launch must be informed in good time to the UN and also that it will be the country of origins duty to ensure it does not fall on anyone and that it does not interfere in any other countries missions and reasonable liability to damage done. It also specifically notes the difference between goverment and non-goverment organisations and notes that they are the responsibility of the Nation they came from.

The Moon treaty is worse it actually notes that it only allows enough material mined or used to allow exploration or for scientific study. It does allow bases to be put on the Moon and for material to be utilised to improve the base and supply it.

So any buisness or private entity who wants to go to the Moon and utilise PGMs or something similar will simply not be allowed they are considered to be part of a nations scientific study and are bound to the treaty and as such cannot do what is needed. Also they cannot hide the fact as they are duty bound to inform the UN cannot build bases that block other countries from areas of the Moon nor stop observers from entering your base and check to see what you are up to.

Lets hope that this treaty gets updated and though there are good sections to it is badly let down by its attempt to be a law of the sea of outer space. Lets also hope that the Moon treaty which has only been taken up by India and France(space powers) is just a treaty that will never become an international prime directive.

noosfractal · 2005-10-24 13:54:05

... any launch must be informed in good time to the UN and also that it will be the country of origins duty to ensure it does not fall on anyone and that it does not interfere in any other countries missions and reasonable liability to damage done ... allows enough material mined or used to allow exploration or for scientific study ... cannot hide the fact as they are duty bound to inform the UN cannot build bases that block other countries from areas of the Moon nor stop observers from entering your base and check to see what you are up to ...

I'm sure extranational entities would be highly motivated to maintain good relationships with national and international entities - particularly those nations that haven't signed the treaty. The information requirements are not overly burdensome. I agree that there should be no non-scientific research. Again, I don't see the problem.

However, as you say, it is probably just as easy to lobby the appropriate politicians and have the law changed. It is widely recognized that multiple biospheres are required to ensure long term human survival, so it is just common sense.
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Grypd · 2005-10-24 15:08:24

"noosfractal wrote:

I'm sure extranational entities would be highly motivated to maintain good relationships with national and international entities - particularly those nations that haven't signed the treaty. The information requirements are not overly burdensome. I agree that there should be no non-scientific research. Again, I don't see the problem.
However, as you say, it is probably just as easy to lobby the appropriate politicians and have the law changed. It is widely recognized that multiple biospheres are required to ensure long term human survival, so it is just common sense.
.
There is only one extranational entity that is the United Nations there is no other existing extranational organisations and to create one for space would in all likehood be physically impossible. To first of all have enough population to be able to be taken seriously will be impossible without heavy resource utilisation and the only way it would be able to pay its way would require it to be selling resources and products back to Earth. All of which it would not be able to set up before it had the population and personel to be able to say it was an extranational organisation or country.
The Outer space treaty was ground breaking when it first appeared it stopped the likehood of the Moon and space becoming an armed camp and gave the various space pushes a protection that has kept weapon firing in orbit from happening. It just went to far saying that all of space is the property of all of mankind is good but useless without the ability to use these great resources. In this is it failed. The Moon treaty is another matter it really is an attempt to bring the law of the sea to space.
So until the treaty is changed or until one of the space powers decides to legally walk away from the treaty, private enterprise is constrained and uncertain. It cannot raise the capital to pay for the Billions. The fundamental reason for law is to enshrine what a person owns and what they are allowed to do with the property. For private enterprise to be able to raise the funds to make succesful use of outer space it needs to be able to be sure of what it owns. If they find a very rich source of anythingyum then they will want to be sure that they can use there find for a profit. They must have the ability to show the investors that they own or have rights to a real tangible substance and time to do it in. They must be able to send anythingyum to Earth and not be forced to give it away to any country that asks for it.

Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#26 2005-10-15 23:31:36

Re: Lunar Carbon?

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