ISRU questions

[Engineer817]

Greetings,
I've been playing with an idea of a boot strapping ISRU system for a while and have a general idea of how the concept will work, but there are quite a few bugs to work out. Since most ISRU questions are in the advanced concepts category, I figured that it would probably fit right in. My questions are:
after extracting the aluminium from the highlands, are there any methods for turning it into wire? What about coating the wire?
Another question is how to create different lunar glasses and what their respected uses would be. I've tried looking for articles, but none go indepth.
and lastly, can resistors be made from ironoxide on the moon? I haven't found any material on that aspect of production.
thanks for any consideration,
Ryan

[QuantumG]

Welcome to the forum!

This doesn't answer your question, but it taught me something I didn't know:

http://en.wikipedia.org/wiki/Aluminum_wire

Going more general:

http://en.wikipedia.org/wiki/Wire_drawing

Sounds like an easy enough thing to experiment with in a garage.. people regularly make their own aluminum furnaces, etc.

can resistors be made from ironoxide on the moon?

Why not just aluminum oxide?

[Engineer817]

why not indeed? But would it be easier to produce aluminum oxide then mining and refining iron oxide? whats the benefits or problems of either?
Thank you for the links, but the wire drawing requires a larger wire in the first place. being able to create the wire and coat it will take care of most the power transition problems, but I can't find a suitable coating anywhere. With the electrical properties of the lunar soil, you need a covering of some sort. And it would be purpose defeating to import it. An idea I had was using power poles, but that would be hard to implement due to the height and near unserviceability of the lines. Then again, having short poles and less space between them could work, but you could be blocking robotic routes...

My main area of interest however is glass and solar cell manufacture. I haven't found very much on glass production, and only a reference to solar cells made insitu by rovers. I can't seem to find that article either.

[QuantumG]

Wire drawing works by making thicker wires thinner, yes.. eventually, your input "wire" is not something you'd typically call a wire at all

[Engineer817]

I suppose you're right, but you still have the problem of going from the melting pot to the long strand of aluminum. And of course the coating...
still hopping that some one can point me in the right direction for the silicone problems.

[QuantumG]

Wire drawing starts with an ingot.

As for coating the wire, what's wrong with aluminum oxide?

You're at the beginning of a very long journey. Read, read, read.

[randomly]

and lastly, can resistors be made from ironoxide on the moon? I haven't found any material on that aspect of production.
thanks for any consideration,
Ryan

Resistors for what purpose? Power resistors, precision resistors, resistors as electronic components or high power systems? All have different characteristics and design tradeoffs. One of the major ones being the thermal coefficient of resistance.

There are many different materials and construction techniques that can be used to make resistors each with it's own advantages and drawbacks, accuracy, drift, parasitic inductance and capacitance etc.  There is no one size fits all design.

[RocketmanUS]

coating the wire?

You will need to know the environment your wire will be in. Different coatings for different environments. Mars , moon surface , in space in direct Sun light or no light at all, or will it be in a hab.

[Robert Thompson]

Lunar solar power generation, Lalith Kumar, July 2006
http://ubiquity.acm.org/article.cfm?id=1149636

Solar Power via the Moon, David R. Criswell, 2002
http://www.tipmagazine.com/tip/INPHFA/vol-8/iss-2/p12.pdf

(http://www.spacehike.com/criswell.html)

Lunar Production of Solar Cells, Geoffrey Landis, 1989
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890018248_1989018248.pdf

"Lunar resources utilization for space construction", General Dynamics, 1979
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830077470_1983077470.pdf

Lunar solar power generation
http://www.appropedia.org/Lunar_solar_power_generation

[Engineer817]

quite a few things to address

As for coating the wire, what's wrong with aluminum oxide?

Aluminum oxide seems to have a higher melting point then the wire it would be coating. With the vacuum properties of the moon, you won;t be able to cool it down conventually, and it might turn the wire its coating into a pool of slag. I like this idea, though it has a couple of issues.

Resistors for what purpose? Power resistors, precision resistors, resistors as electronic components or high power systems? All have different characteristics and design tradeoffs. One of the major ones being the thermal coefficient of resistance.

There are many different materials and construction techniques that can be used to make resistors each with it's own advantages and drawbacks, accuracy, drift, parasitic inductance and capacitance etc.  There is no one size fits all design.

Thanks for the heads up, gives me another area to research

coating the wire?

You will need to know the environment your wire will be in. Different coatings for different environments. Mars , moon surface , in space in direct Sun light or no light at all, or will it be in a hab.

This will be the power lines to the solar cells that will be built later. Out side use only.

Lunar Production of Solar Cells, Geoffrey Landis, 1989
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890018248_1989018248.pdf

Thank you, this gave me exactly what I needed.

Thanks for all your replies. I'll reply to this thread as I continue this project and devolop more questions. Thank you very much

[Robert Thompson]

http://adsabs.harvard.edu/full/2004ESASP.567..173I
Solar Cell Development on the Moon from In-Situ Resources, Ignatiev Freundlich Horton, 2004

[Heinrich]

...after extracting the aluminium from the highlands

Two steps back: How are you going to convert Alumina (=aluminium oxide) into aluminium? This is a process which requires a large heat and electrical input.

http://en.wikipedia.org/wiki/Aluminium

I think ISRU should start with a focus on producing GOX / LOX both for lifesupport, and for propellant. Anything else would appear to me as very long term. Start with bringing solar panels, cabling, etc to start a lunar base. Relative small scale O2 production (for life support) should be feasible when enough power is available.

[Eer]

I wonder if the introduction or availability of 3d material printing will significantly alter approaches to bootstrap ISRU. 

Case in point - the production of proto-wires via 3d printing of various native resources, perhaps including their insulation coating.

Granted, you have to get both the power generation (not least to facilitate material refining) and the printer into place, but the notion of a "self replicating base station" has a certain appeal to it.  This 3d printing stuff is the first approach I've heard that makes such a vision seem more than just a dream.

How far can it take you?

Edit:  highlight power requirement to refine materials, in addition to drive the printer.  Of course, the real test of a self replicating base station will be to create a self replicating 3d printer and its associated refinery machinery.

[Engineer817]

Two steps back: How are you going to convert Alumina (=aluminium oxide) into aluminium? This is a process which requires a large heat and electrical input.

http://en.wikipedia.org/wiki/Aluminium

I think ISRU should start with a focus on producing GOX / LOX both for lifesupport, and for propellant. Anything else would appear to me as very long term. Start with bringing solar panels, cabling, etc to start a lunar base. Relative small scale O2 production (for life support) should be feasible when enough power is available.

To address the aluminum problem, the oxide will be made from the aluminum, not the other way around. I've done a bit of research into extracting aluminum from anorthsite and the process is fairly straight forward (except the anode's composition)
I will also say very straight forward and clearly, that human habitation or colonization is NOT with in my goals or concerns until much later in the game. I will avoid any notion to settling people on the lunar surface. I know I am going to make a lot of enemies by just saying that, but with price tags of billions of dollars, I hope you understand my reasons.
Propellant is one of the goals, but its a secondary goal only to be achieved as soon as the equipment can be made to mine the "ore" and then process it into fuel.

I wonder if the introduction or availability of 3d material printing will significantly alter approaches to bootstrap ISRU. 

Case in point - the production of proto-wires via 3d printing of various native resources, perhaps including their insulation coating.

Granted, you have to get both the power generation (not least to facilitate material refining) and the printer into place, but the notion of a "self replicating base station" has a certain appeal to it.  This 3d printing stuff is the first approach I've heard that makes such a vision seem more than just a dream.

How far can it take you?

Edit:  highlight power requirement to refine materials, in addition to drive the printer.  Of course, the real test of a self replicating base station will be to create a self replicating 3d printer and its associated refinery machinery.

This is the proposition in its entirety. The 3d printing system is a base line for what I have in mind. I'd rather not go into too much detail at the moment, but combining the 3d printer's transition table (with some modifications) and the initial processing plant will save space, weight, and power. Once I've finished the proposition document, I'll think about releasing it onto the WWW. Also, its not self replicating. Its just building other components.

[KelvinZero]

Given the billions of people whom have no particular interest in putting me on the moon right now, it would seem a bit unfair to single you out for my vitriol

Sounds like a great project whatever level you can take it to.

[RocketmanUS]

For Lunar would the aluminum oxide. Even if it does not would it need to have an insulated coating?

Crazy idea.
Lay down tracks made of aluminum between the base and the solar panels. Use the tracks to carry the power. AC for low loss and should result in cooler lines plus the size of the tracks compared to electrical lines. Vehicles to use the tracks for power and a guide to were they are going. Vehicle weight would not be on the tracks as the vehicle would use tires on the ground. Tracks are for supplying power for the vehicle, not for the vehicle to drive on it. This way the vehicle can be fully charged when it gets to the end of the line and could then travel further on battery power.

Other idea is to use micro wave transmission between the solar panels and a base. The power could also be transmitted from panels to a mobile power receiver extending the range of vehicles. Could also relay power from one repeater to another till it reaches were it is needed.

So the idea is to place solar panels around the moon and have them connected to a base so it has power coming in for most of the time?

How much energy will it take to make a 100W panel, include all processing needed from mining the elements to final product?

[Engineer817]

Sounds like an interesting idea, but since the power stations will be primary used as power stations for mining operations and the extra it stores sent to the other components of the base, the only vehicle that will need to go back and forth would be the hauler with the exception of damaged or specialized robotics. I'll keep that in mind though. As for the power needed to create the products, there would be a level of guess work since there is no exact amount of material to process, no exact power a robotic unit will use recovering it, and no exact amount of power that the unit will produce. A lot of estimation would be involved, but I'll play with the numbers a little later.

[RocketmanUS]

Sounds like an interesting idea, but since the power stations will be primary used as power stations for mining operations and the extra it stores sent to the other components of the base, the only vehicle that will need to go back and forth would be the hauler with the exception of damaged or specialized robotics. I'll keep that in mind though. As for the power needed to create the products, there would be a level of guess work since there is no exact amount of material to process, no exact power a robotic unit will use recovering it, and no exact amount of power that the unit will produce. A lot of estimation would be involved, but I'll play with the numbers a little later.

Then start with how much energy it takes here on Earth at the manufacture for the cells. So if we need a total of 100 watts of cells how much energy is used just to make the needed amount of cells used on a 100W panel here on Earth? That is taking the needed elements at the factory to the point of shipment, not counting the packaging.

We will have to see if it is better for now just to send panel to the moon or make them there.

Edit:
Also look into using reflected light to reduce the amount of panels needed. Panels that I know of will burn out if added light was used on them, only rated to the amount the Sun would provide on the brightest day. There is also the use of a lens to focus light that is used on one type of panel. That might be workable on the moon to reduce the amount of panels needed.

Added thought, could it be possible to use lenses to redirect the Sun light from one place to another instead of mirrors? Would this have less loss of the solar energy?

[ArbitraryConstant]

Also look into using reflected light to reduce the amount of panels needed. Panels that I know of will burn out if added light was used on them, only rated to the amount the Sun would provide on the brightest day.

A good idea, but not new, and yes cooling is a big deal. Concentration over 1000 suns has been demonstrated. The other thing about this technology is that they tend to use the extremely efficient multi-junction cells. These have been demonstrated over 40% efficient.

[frobnicat]

Then start with how much energy it takes here on Earth at the manufacture for the cells. So if we need a total of 100 watts of cells how much energy is used just to make the needed amount of cells used on a 100W panel here on Earth? That is taking the needed elements at the factory to the point of shipment, not counting the packaging.

We will have to see if it is better for now just to send panel to the moon or make them there.

wikipedia "net energy gain" about solar cells on earth :
<<Today the break-even energy payback time (the amount of time required to produce an amount of energy equal to that originally used to manufacture the array) is around one to four years>>
Anyone knows if its taking into account all process from raw ore ? Moreover on earth we have convenient access to relatively cheap concentrated sources of volatiles like fluorine for semiconductor process... And it's not just a question of energy but cost. Setting up an autonomous solar cell factory on the moon would be a huge initial investment + key components are to be robust enough that they are still operational when "breaking even" : wear and tear of high temperature furnaces, chemical vapor deposition chambers, high precision abrasive tools ... those elements, often using key scarce materials, usually need a complete industrial network to be produced or repaired.
Alternatives might be possible, contactless processes with lasers... but need to be specifically developed, not yet economical for production on earth (limited yields, costs). Seems most probable is first ISRU for structural elements (sintered soil...) long before local semiconductor production, or even metallurgical grade machined materials. Semiconductor parts might be the last thing we produce in-situ !

Added thought, could it be possible to use lenses to redirect the Sun light from one place to another instead of mirrors? Would this have less loss of the solar energy?

Thin Fresnel lenses then. I don't see how it could be better than aluminium coated thin mirrors, with a much simpler geometry. Wouldn't solar thermal, with in situ produced mirrors concentrating on an earth sent Stirling engine/generator, be more feasible than going solar cells ?