Designing a (Totally) self sufficient Mars colony

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Ciber
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Designing a (Totally) self sufficient Mars colony

Postby Ciber » Thu Apr 11, 2013 5:04 am UTC

NOTE: This thread will not be discussing Terraforming, Location, or how we get every thing there in the first place. What this thread is meant to do is figure out all the material flows that need to be established to achieve self sufficiency.
NOTE2: Self sufficiency will be defined as the ability to manufacture on site all the equipment which is required for the base to operate indefinitely.

I think that it will be easiest to start with one smaller thing and work backwards from that.
As such, our first topic of discussion will be Housing. To elaborate, how will we construct air tight buildings in which we can house colonists.

We have the following sub-topics to discuss:
    Structure: What the thing is actually made of.
    Sealing: How do we make it air tight.
    Air-Locks: Getting in & out
      Doors: Has to withstand the pressure yet be easily opened/ closed
      Sealing: The doors need to form some type of seal that is tolerant of wildly differing pressures and temperatures.
      Pumping: Has to keep the airs from mixing.
      Control: computerized or some clever mechanical system, we need to ensure that only one door is open at a time.
    Utilities: Provide a way to hook up with the rest of the bases water, electricity, life support, and networking.
      Piping: shutoff valves are also probably important.
      Wiring: Get those electrons moving!
      Sewage/toilets: Can't exactly go outside to use the latrine.
    Flooring: Bare feet do not like to meet with cold tiles.
    Bedding: Well they aren't sleeping on the floor!

Feel free to suggest more sub-problems that we can break this down into.

Initially, I think that the structure should be some type of brick barrel vault covered in regolith to keep it under compression and for sealing we can just humidify the air and as it seeps into the walls and freezes it will form an airtight seal.

Well I am going to sleep but I cannot wait to see your thoughtful replies when I wake up!
Last edited by Ciber on Sun Apr 14, 2013 5:05 pm UTC, edited 1 time in total.

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Re: Designing a (Totally) self sufficient Mars colony

Postby p1t1o » Thu Apr 11, 2013 3:17 pm UTC

Do we really have to discuss the pumping mechanisms for our airlocks? I'm pretty sure we can use off-the-shelf NASA technology for that. Unless you want to manufacture indigenous machinery on-planet?

Here's one approach:

Take an average nuclear submarine and transport it to Mars.
The only thing limiting the self-sufficiency would be food, at least whilst the nuclear fuel lasts.
But then at least we have a well-equipped, resilient, almost completely self-sufficient base which we can use whilst we set up farming, an alternative power station and construct further places of residence.

I suppose we could remove the nuclear missile and torpedo tubes (if you want to be boring) and replace them with hydroponics and/or fermenting vats (not for beer, for quorn). You'd definitely have to face the fact that the colonists are going to have to be vegetarian for quite some time.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Xenomortis » Thu Apr 11, 2013 3:36 pm UTC

Nuclear submarines depend on the sea-water medium for cooling.
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Re: Designing a (Totally) self sufficient Mars colony

Postby p1t1o » Thu Apr 11, 2013 3:51 pm UTC

Really? Dang, didn't know that, kinda ruins how neat a solution it was :(
Its a complication, but given that the outside temperature is likely to be at least several tens of degrees below zero (Celsius) this might not be insurmountable with some sort of radiator or gas-cooling loop.

Since solar or wind power are pretty much out, it seems we'd have to stick with nuclear at this point.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Xenomortis » Thu Apr 11, 2013 3:54 pm UTC

The outside is also lacking in much of a medium. :)
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Re: Designing a (Totally) self sufficient Mars colony

Postby p1t1o » Thu Apr 11, 2013 4:11 pm UTC

Radiators it is then - unless possible to land at a pole and boil off dry ice for cooling.

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Re: Designing a (Totally) self sufficient Mars colony

Postby ahammel » Thu Apr 11, 2013 4:12 pm UTC

p1t1o wrote:Since solar or wind power are pretty much out, it seems we'd have to stick with nuclear at this point.
Wind is one of the few resources that Mars has in abundance, in fact. Although it's probably a "too much of a good thing" situation in this case.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Thu Apr 11, 2013 4:12 pm UTC

We are specifically speaking about how to natively manufacture every single item from the smallest bolt all the way up to entire SSTO's. This includes the pumping mechanism. Though now that I think about it, as long as we have large enough oxygen production, it should not matter if we loose a little bit of air every time we open the airlock.
I am in favor of an entirely mechanical design. I am working on one now that will only allow one door to be open at a time and they will be opened like bulkheads with the big wheel in the center.

Wind is not that great on mars, sure it is fast but it is also very insubstantial.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Thu Apr 11, 2013 4:16 pm UTC

Build it primarily from martian materials. Concrete from regolith. Magnesium is plentiful; alloy that shit up. Most of the atmosphere is comprised of CO2; pressurize it and inflate some greenhouses. React it with Hydrogen, bam, CH4 + Oxygen. You can also convert it to C2H2, bam, plastics industry.

There's probably a ton of frozen water at the north pole.

My favorite proposed model was growing crops in green houses, composing the waste assisted by mushrooms, and feed some of the waste to tilapia fry.

Ultimately, I think nuclear power is a must to get things going.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Seraph » Thu Apr 11, 2013 4:27 pm UTC

ahammel wrote:
p1t1o wrote:Since solar or wind power are pretty much out, it seems we'd have to stick with nuclear at this point.
Wind is one of the few resources that Mars has in abundance, in fact. Although it's probably a "too much of a good thing" situation in this case.

Mars may have high wind speeds, but wouldn't the fact that it's atmospheric pressure is like 1/200ths of Earths mean that there isn't actually very much energy in that wind?

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Re: Designing a (Totally) self sufficient Mars colony

Postby ahammel » Thu Apr 11, 2013 4:35 pm UTC

Seraph wrote:
ahammel wrote:
p1t1o wrote:Since solar or wind power are pretty much out, it seems we'd have to stick with nuclear at this point.
Wind is one of the few resources that Mars has in abundance, in fact. Although it's probably a "too much of a good thing" situation in this case.

Mars may have high wind speeds, but wouldn't the fact that it's atmospheric pressure is like 1/200ths of Earths mean that there isn't actually very much energy in that wind?
Googling suggests that the average wind speed on mars is only 3 or 4 times that on earth, so yes, you are correct. Ignore me.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Tass » Thu Apr 11, 2013 8:21 pm UTC

Izawwlgood wrote:There's probably a ton of frozen water at the north pole.


Hopefully a lot more than that :p

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Re: Designing a (Totally) self sufficient Mars colony

Postby Xenomortis » Thu Apr 11, 2013 8:41 pm UTC

p1t1o wrote:Radiators it is then - unless possible to land at a pole and boil off dry ice for cooling.


I realise that I'm being a little snarky and only giving problems, but:
Radiation is really bad for cooling; the energy given off is too low at reasonable temperatures.

The only thing I can think of is to try to conduct excess heat into the ground; I have no idea how successful that could be. Alternatively, try to find large amounts of native water (in any form) and use that.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Thu Apr 11, 2013 8:59 pm UTC

As it happens, the purpose of this thread is to define the problem!

Right now I want to concentrate on how we will make the airlock doors have an air tight seal. To do this we will probably want some sort of sealant that retains some measure of squishyness when in a near vacuum at temperatures significantly below freezing.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Thu Apr 11, 2013 9:03 pm UTC

The temperature of Mars ranges from significantly below freezing (-140F) to right around freezing (36F).

I don't think airlocks are really that tricky; if we can make airlocks on submarines or space stations, we can make airlocks on Mars.
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Re: Designing a (Totally) self sufficient Mars colony

Postby ahammel » Thu Apr 11, 2013 9:06 pm UTC

Izawwlgood wrote:I don't think airlocks are really that tricky; if we can make airlocks on submarines or space stations, we can make airlocks on Mars.
I imagine the main unique obstacle to just about anything mechanical will be that the goddamn dust fines get into everything.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Thu Apr 11, 2013 9:19 pm UTC

Yeah, that will be an issue. Static charge? Blast of pressurized air to dislodge anything?

I think it's important to realize that Mars has, literally, a planets worth of materials to utilize. You don't need to bring everything.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Fri Apr 12, 2013 2:27 am UTC

Exactly! Thats the point of this thread! To figure out how to turn all of those resources into usable items!

If anyone could find some articles on how airlocks achieve an air tight seal that would be super great!

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Re: Designing a (Totally) self sufficient Mars colony

Postby Scyrus » Fri Apr 12, 2013 2:34 am UTC

ahammel wrote:
Izawwlgood wrote:I don't think airlocks are really that tricky; if we can make airlocks on submarines or space stations, we can make airlocks on Mars.
I imagine the main unique obstacle to just about anything mechanical will be that the goddamn dust fines get into everything.


Would it be possible to make a glass dome-like structure surrounding the colony that would provide cover for sandstorms and protection from radiation? Without a magnetosphere, I think one of the great challenges is the constant, all encompassing, atmosphere sabotaging solar wind.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Fri Apr 12, 2013 2:59 am UTC

My current plans call for roman style brick barrel vaults with five meters of compacted regolith on top. More than enough to deflect inclement weather and radiation.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Fri Apr 12, 2013 3:04 am UTC

Yeah, humans won't be living on the surface of Mars for some time. And no one knows how much frozen water or volatiles there is, so, it's possible that terraforming that's too gradual will result in most of the gas just being blown away, and it's possible that it'll just take a bit of thickening to result in a run away heating event that can maintain itself.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Xenomortis » Fri Apr 12, 2013 7:45 am UTC

Scyrus wrote:Would it be possible to make a glass dome-like structure surrounding the colony that would provide cover for sandstorms and protection from radiation? Without a magnetosphere, I think one of the great challenges is the constant, all encompassing, atmosphere sabotaging solar wind.


Step1:
Create massive horseshoe magnet with ends at the poles.
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Re: Designing a (Totally) self sufficient Mars colony

Postby ian » Fri Apr 12, 2013 10:06 am UTC

Just because no one else has mentioned it, Kim Stanley Robinson's Mars trilogy (particularly the first one 'Red Mars') would be of great interest to the OP.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Fri Apr 12, 2013 2:12 pm UTC

Yeah, I sort of thought that was a given. Like, you want to talk about the social biology of the ant? You might want to read something by EO Wilson.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Fri Apr 12, 2013 4:08 pm UTC

Read it.

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Re: Designing a (Totally) self sufficient Mars colony

Postby idobox » Fri Apr 12, 2013 7:12 pm UTC

Airlock seals are not that big, and I think they should be the kind of things you bring with you.

I'm all in favour of bringing tunnelling machines to dig habitat, but making bricks out of Martian soil might be easier, a sort of robotic spray paint machine with a tank of resin to make the tunnels airtight. Add a few airlocks, and you have a nice habitat.

RTG are a proven technology for power generation that will not be easily beaten in low pressure atmospheres. I also love the idea of nuclear furnaces to melt and smelt stuff. Power (not only electrical) is the critical part, because if you have enough of it, you can make whatever you want with local rocks. And nuclear is the way to go for lots of consistent power.

If you can produce metal, concrete and glass from local resources, you have pretty much all the heavy stuff required to build a base. We also know water ice is present and can be harvested if the base is close enough. Now you just need to build a bunch of photobioreactors on the surface, seed them with algae, connect them with metal pipes, and you have oxygen and food production running. I think you will also need a compressor to inject atmospheric CO2 in the system and increase the biomass, as well as a few hundred kg of salts and other oligo-elements that can't be retrieved by putting Martian rocks in water.

I also think you definitely need an electron-gun metal 3D printer, and a machine to make metal powder from local resources (mostly aluminium and iron I assume). Making a decent vacuum will not be very difficult, you will a variety of metal pieces, and electron guns are very efficient at heating metal.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Fri Apr 12, 2013 7:19 pm UTC

Nuclear furnace... Does that...exist?

Really good list though idobox, I think that brings a lot of stuff together.

What about Mars-suits? The low pressure means you can't just wrap someone up in insulating clothing, but you don't need something as extreme as a bulky space suit? Of course, as with all things on Mars (and Luna too!) my sense is that the particulate fines are going to be incredibly problematic, and some kind of static shielding is going to be needed for just about everything exposed to the environment. I'll have to read up a bit on how NASA deals with it on the rovers.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Fri Apr 12, 2013 9:24 pm UTC

Importing sealant from earth goes entirely against the concept of a Totally self sufficient mars colony!
We need to figure out this most basic of problems or all of our efforts are for naught!

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Fri Apr 12, 2013 9:39 pm UTC

...
Again, sealing the airlocks isn't terribly tricky sounding. Plastics are fully doable from ethylene, and my sense is that most airlocks on submarines/spacecraft aren't made from anything non-reproducible with Martian materials. The issue of fines is likely addressable with a couple easy work arounds.

And mind you, you can and should send some things to get them started. You don't want to just drop some Aeronauts on the planets surface with nothing but a days supply of oxygen, food, and a hammer.
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Re: Designing a (Totally) self sufficient Mars colony

Postby gmalivuk » Fri Apr 12, 2013 10:52 pm UTC

Ciber wrote:Importing sealant from earth goes entirely against the concept of a Totally self sufficient mars colony!
Doing it regularly, sure. Sending them there with some in the first place, however, in no way goes against the concept of self-sufficiency. As Iz says, you're not just going to drop them naked on the surface and expect them to do everything else locally, are you?

After all, there are no trees to punch.

Izawwlgood wrote:my sense is that the particulate fines are going to be incredibly problematic
Something I've seen (I think in Clarke and Baxter's Time's Odyssey trilogy) is suits that were essentially detachable sections of habitat hull. That way no surface that had been exposed to Martian fines was ever also exposed to the inside of the habitat, where presumably you'd be doing most of your clean work.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Fri Apr 12, 2013 11:41 pm UTC

Well of course we are sending them there with all required machinery, I am not even against sending them with an ample supply of spares and small parts. BUT the entire point of this exercise is Total self sufficiency, which means that at some point in the future we need to be able to build every single thing on site.
The problem here is how many plastic based sealants are still good at sealing things at martian temperatures?

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Fri Apr 12, 2013 11:57 pm UTC

I'm telling you man, ethylene can be readily synthesized from the atmosphere, and is the precursor to a number of very useful plastics. Some polyethylenes have a functional temperature range between -260F and 150F, and I'm no polymer chemist, but maybe there's stuff that holds up at even colder temperatures. Obviously plastics that become brittle in the lower end of Martian weather may be unusable for certain activities, but the airlock and suits and such can be heated.

And yeah, build everything you want on site; I don't think you need much more than seed materials (and in some case, literally seeds!), but don't discount bringing stuff. For example, if you're genetically modifying life for specific use, don't expect to do your initial genetic engineering on Mars; bring that shit with you! Plan ahead! Lewis and Clark lived off the land, but you better believe they brought the tools to do so.

@Gmalivuk: I remember reading however that the lunar walks all ended up with surprisingly high quantities of dust in the joints and fibers of the suit, and fines accumulated far more rapidly than anticipated. I think unless you have some sort of repellant or way of dealing with the persistent abrasion, you may find things not lasting very long. Cleaning the fines out is probably fairly simple with some sort of fluid or static charge though. I'm curious about detachable habitat though; it seems like a pretty useful way of maintaining outside/inside separation.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Sat Apr 13, 2013 12:36 am UTC

That's great! So we can add atmospherics ethylene synthisization to our list!
Now that we have a potential solution to the sealant problem, lets move on to the actual doors.
I am thinking a heavy bulkhead design with a central wheel that you turn to extend/retract pistons that lock the doors in place. I think I figured out a simple mechanical way to link the doors so that you cannot open one unless the other is completely closed.
This would require the ability to cast large chunks of metal, machine fairly accurately, some type of lubrication for the hinges, and the sealant is all ready accounted for.
This is of course the super low tech solution, other ideas are welcome.
I think that both doors should open inward towards the airlock, and the airlock should be large enough that if both doors were open at the same time that would not touch. Both doors should open towards the same side of the airlock so that the other side would always be open for other equipment.
Of course I can think of multiple ways that the inclusion of simple electronics could improve this design, but this is just my simplest fleshed idea.

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Re: Designing a (Totally) self sufficient Mars colony

Postby PM 2Ring » Sat Apr 13, 2013 7:18 am UTC

Ciber wrote:for sealing we can just humidify the air and as it seeps into the walls and freezes it will form an airtight seal.

Cute idea, but I suspect that the rock will suck up an awful lot water. The water will tend to diffuse through the rock unless it's totally impermeable to water, which is rather unlikely, since Martian rocks tend to be mostly anhydrous & contain minerals that water will happily hydrolyze.

Water is rather mobile stuff. Even if the ambient temperature is well below 0°C it can sublimate, especially if the ambient atmospheric pressure is low. So using a polymer like polyethylene as a sealant will prevent your habitat from sucking up large amounts of your precious water supply.

Ciber wrote:Importing sealant from earth goes entirely against the concept of a Totally self sufficient mars colony!
We need to figure out this most basic of problems or all of our efforts are for naught!


Making sealant is a minor problem. The major problem for a self-sufficient extraterrestrial habitat is maintaining its ecosystem: producing oxygen, water and food, and dealing with the biological "waste" materials. Ideally, all bio-waste would be recycled, but unfortunately nobody has yet been able to build a sealed ecosystem capable of supporting humans that can survive indefinitely.

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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Sat Apr 13, 2013 7:46 am UTC

For the curious, check out Biosphere 2. It's monumental failure at least underlined a few important lessons, namely, let the concrete cure before you seal yourself in.

In terms of self-enclosed ecosystem awesomeness, there's a lot of really cool possibilities for cycling. It would have to be on an impressive scale, and would likely take a significant period of time to get up and running, but there's been some cool work with hydroponics and fish, mushrooms in composting, and livestock and agriculture (as in, feed pigs agricultural waste and fertilize the agriculture with their manure).

Some animals would probably be more useful than others. Cows aren't going to have a lot of utility initially, but goats might. Whose ready for the first Martian apiary?
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Re: Designing a (Totally) self sufficient Mars colony

Postby PM 2Ring » Sat Apr 13, 2013 8:50 am UTC

Izawwlgood wrote:For the curious, check out Biosphere 2. It's monumental failure at least underlined a few important lessons, namely, let the concrete cure before you seal yourself in.

Yeah, my previous post was partly prompted the Biosphere 2 fiasco. It's been a while since I read about it, but IIRC the major problem was CO2 being sucked up by the concrete instead of being recycled back into O2 by the plants. But (IIRC) they also had problems with excess levels of various undesirable gases, especially methane. They had to pump in extra O2 to compensate for what the concrete was doing, but that didn't solve their problems because it encouraged the soil bacteria to proliferate, leading to runaway methane production.

Izawwlgood wrote:Cows aren't going to have a lot of utility initially

Probably not. :) Their rumen bacteria churn out lots of methane, and it's not particularly easy to extract methane from air. I guess the easiest way is freeze distillation, but that takes a fair bit of energy since methane has a fairly low boiling point: -164°C at atmospheric pressure. By way of comparison, CO2 freezes to Dry Ice at −78.5 °C at atmospheric pressure. And unlike CO2, which can be liquified at room temperature under moderate pressure (around 20 atmospheres, IIRC), methane needs to be below the temperature of Dry Ice to liquify.

Here's a phase diagram for methane:
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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Sat Apr 13, 2013 4:01 pm UTC

There have been more successful, although admittedly smaller scale, experiments like Biosphere 2. And even though the stated goal of 'seal some people in, and have them survive in there for x months' failed, people seem to not focus on the data that was gathered in the process. Identifying critical failure points in self-enclosed ecosystems of that scale is, as I see it, the whole point; clearly you need to account for chemical processes occurring in your engineering, and hey, look at that, soil microbes play a significant role in this cycle and need to be monitored and controlled.

Heh, the methane production for cows didn't occur to me, but that's a good point! If you can't separate the methane easily from the rest of the recycled atmosphere, that's going to be a problem for methane generating livestock and reactions. That said, if it's not TOO hard (especially if you already have refrigeration from the outside that provides about -100F cooling), and only requires pressurization to ~1 atm, that livestock might be useful for that purpose? Methane has it's uses, and is additionally awesome as a greenhouse gas.

Zubrin wrote a funny bit about how goats would be great, because they'll eat anything. Including whatever you're building the colony out of. Ultimately, the resources required to get milk and meat from a cow is likely to be prohibitive, and there are easier ways to get protein. Chicken would be useful, as they can eat scraps.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Ciber » Sat Apr 13, 2013 9:05 pm UTC

For meat production I was thinking more along the lines of tilapa or some other kind of fish.
How much work do you think it would take to convert martian regolith into stuff that plants can grow in?

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Izawwlgood
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Re: Designing a (Totally) self sufficient Mars colony

Postby Izawwlgood » Sat Apr 13, 2013 9:10 pm UTC

Yeah, tilapia have already been mentioned a few times. Mushrooms are also a good and cheap way to produce protein.

Regolith to soil conversion is likely fairly difficult, and it'll be a while before crops are grown in a non-hydroponics manner. Soil is a fairly complex mixture of organic matter, and Martian regolith is basically just extremely dry rock. It would take multiple cycles of blending with composted material to produce anything approaching arable soil. Hydroponics are the way to go for a variety of reasons for a fledgeling colony, but soil production would have other practical uses, including allowing individual colonists to grow their own plants in their quarters.
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Re: Designing a (Totally) self sufficient Mars colony

Postby Frenetic Pony » Sat Apr 13, 2013 9:37 pm UTC

Terraforming Von Neuman machines, done! Just go for the big, ambitious engineering solution to everything right?

But disregarding the ambitious, but most efficient and all encompassing solution such as that... How much sunlight does mars get? I've seen about 36%, so solar power is out as inefficient. Obviously there's no oil or etc. So you'd have to go with wind, plenty of which there is on Mars, and/or fusion/fission power. Something with high energy output to mass ratio so you're not ferrying fuel all the way there and back.

That's what I got. Heck if you had a fusion power plant just split all that carbon dioxide into carbon and oxygen directly. Why not, you've got power to spare.


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