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SLS / Orion / Beyond-LEO HSF - Constellation => Missions To Mars (HSF) => Topic started by: sanman on 10/18/2014 05:41 PM

Title: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 05:41 PM
Everyone says that hydroponics will be the main way to grow food on Mars - but will it always be?

If the needs of a growing Martian settlement at some point outstrip what hydroponics can provide or be efficiently scaled to, then where do things go from there? Can Earth-like agricultural cultivation methods be adopted, perhaps under transparent pressurized tents/domes/etc?

What would post-hydroponic Martian food cultivation look like? Will there be a need for a lot of genetic engineering? Could some cultivation methods even be used for bioremediation to convert Martian soil into something more arable, fertile, and crop-friendly?

http://www.theguardian.com/science/2014/oct/18/humble-potato-poised-to-launch-food-revolution

I was reading about the launch of a new salt-tolerant potato which some claim could revolutionize agriculture. There are also plants like the Chinese brake fern which can absorb arsenic from ground soil, and which has been used in bioremediation of toxic spills.

How will agriculture be progressively scaled up on Mars?





Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 10/18/2014 05:48 PM
Nah, we'll be doing hydroponics because pressurized volume is too expensive. Not big tractor things.

I think we'll be getting 90% of our calories from vats or tubes, though. Scales much better on a place like Mars.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 05:59 PM
Hmm, couldn't lower-cost pressurized envelopes be used, which aren't man-rated for safety? After all, if one of your agro-tent envelopes springs a leak and the crops in it die, then it's not as serious when there were no people in it. I was imagining a situation where you'd have many such tents, and they might have robots in them to tend the crops. You might even have animals in them too.

It'd be a shame to let all that Martian real estate to go to waste and only use bottled-up hydroponics.

So why not simple inflatable crop-habitats?
Title: Re: Scaling Agriculture on Mars
Post by: Apollo-phill on 10/18/2014 06:23 PM
Here's maybe what post-hydropinic MArs "greening" may look like ;D ;D


Apollo-phill
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 10/18/2014 06:26 PM
How will agriculture be progressively scaled up on Mars?

By building more and more high-tech greenhouses and algae/bacteria/fungi vat food factories.

It'd be a shame to let all that Martian real estate to go to waste and only use bottled-up hydroponics.

That's akin to thinking it's a shame that there aren't lush corn fields in McMurdo Dry Valleys (http://en.wikipedia.org/wiki/McMurdo_Dry_Valleys). How much nicer it would be to live in Antarctica if there were!?

The real estate is useless to open field farming, in Martian case the entire planet. Tough but must deal with it.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 06:40 PM
Heh, yes I know these images seem Heinlein-esque and almost pastoral -- but hey, rockets landing on their tails used to seem that way too in previous decades, and yet they look quite doable now.

There are examples of huge tent structures here on Earth, and newer materials like graphene hold the promise of making super-strong versions of them. Mars is an extremely low-pressure environment, and so inflating and supporting similar structures with atmospheric pressure in its lower-gravity shouldn't seem like an outright fantasy.

As long as you're willing to accept some statistically high rate of pressure containment failure for your crop enclosures, then you could get away with lower-cost enclosures.

I thought one of the key attractions of Mars is its abundant off-world real estate, and so surely there must be a way to make use of that for the purpose of human sustenance there.


Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 10/18/2014 06:42 PM
There are extensive greenhouses in Minnesota and Arizona for growing food hydroponically all year round. Could as well be at McMurdo.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 06:47 PM

It'd be a shame to let all that Martian real estate to go to waste and only use bottled-up hydroponics.

That's akin to thinking it's a shame that there aren't lush corn fields in McMurdo Dry Valleys (http://en.wikipedia.org/wiki/McMurdo_Dry_Valleys). How much nicer it would be to live in Antarctica if there were!?

The real estate is useless to open field farming, in Martian case the entire planet. Tough but must deal with it.

McMurdo Dry Vallies could be made more fertile if there weren't legal treaties in the way, and if enough effort was put into it. When you're living hundreds of millions of miles away from Earth, and if you and your colleagues are numerous enough, then there could be a lot of incentive to develop Martian real estate, perhaps through cheap low-cost pressure envelopes.

And why not use higher-risk less-safe low-cost containment envelopes for crops? I don't know if there will be a PETA on Mars to complain about putting animals at risk, but surely there won't be crop rights activists complaining about putting crops at risk over there. Your crops would be your "canary in the coalmine" which could be kept in the less safe lower-cost areas, because you don't mind putting them at risk.

Title: Re: Scaling Agriculture on Mars
Post by: R7 on 10/18/2014 06:53 PM
McMurdo Dry Vallies could be made more fertile if there weren't legal treaties in the way, and if enough effort was put into it.

Not without greenhouses packing a lot of heating and lighting. If you build those they will be the expensive premium real estate from which you want the best possible yields, meaning you end up with high-tech hydroponics.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 06:53 PM
There are extensive greenhouses in Minnesota and Arizona for growing food hydroponically all year round. Could as well be at McMurdo.

Yes, "greenhouse" is the better word I should have been using.

Big low-cost inflatable greenhouses. They would take in solar energy, and grow the crops. And because you'd have many of them for redundancy and over-production, you'd be tolerant to containment failure risk.

Maybe places like McMurdo would be the best locations to do a dry-run for such technology, before taking it to the Moon and elsewhere. But there are probably treaties which make such testing illegal. Perhaps Greenland, or Siberia, or the Arctic circle, some other similarly cold and barren wastelands then?
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 06:59 PM
Not without greenhouses packing a lot of heating and lighting. If you build those they will be the expensive premium real estate from which you want the best possible yields, meaning you end up with high-tech hydroponics.

What about if you had a higher-pressure CO2 atmosphere -- or some atmosphere that's very friendly to plants, even if it's not friendly to humans. I see what you're saying that such things are practically just hydroponics by any other name, but it seems to me that cultivating under a gaseous atmospheric environment would be more scalable than doing it in a liquid medium like hydroponics does. You want to avoid the expense of hydroponic pumps, etc.

You might need some heating for the nighttime, but during the day you should be soaking up solar rays for heating.

Is there any such thing as "gaseous hydroponics", even here on Earth?
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 10/18/2014 07:03 PM
Nah, we'll be doing hydroponics because pressurized volume is too expensive. Not big tractor things.

I think we'll be getting 90% of our calories from vats or tubes, though. Scales much better on a place like Mars.

The future of fully synthetic food has been pitched since the 1950s and hasn't caught on for good reason.

Food must be much more then simple nutrition NASA learned this early in the space program.
It also must be enjoyable to eat as well as this is very important to the morale.

Morale is every bit as important as basic nutrition in the long term as it effects health.

Farming on Mars will likely involve lots of hydroponics or aeroponics early on along with aquaculture.

Some examples of what a Mars food system may look like.

https://www.youtube.com/watch?v=_Nfcat6jXBo

https://www.youtube.com/watch?v=84zh7XL15n8

The presence of plants and fish also will contribute to the habitat feeling like home vs sterile and foreboding.
Some plants may even be there mostly for decorative purposes outside of making O2.

Later on when there is use of Martian materials in building structures like large domes we may see more conventional looking farming practices and maybe even use of tractor like things working soil if that proves more cost effective.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 10/18/2014 07:06 PM
liquid medium like hydroponics does.

Hmm, do you have the terminology right? Hydroponics doesn't mean things are grown immersed in liquid. Plants grow in inert substrate like sand. Nutrients are fed in the watering of the plants. The substrate must not be soaking wet, that would kill most crops plants because the roots suffocate.

Quote
Is there any such thing as "gaseous hydroponics", even here on Earth?

Aeroponics (http://en.wikipedia.org/wiki/Aeroponics)
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 10/18/2014 07:27 PM
Nah, we'll be doing hydroponics because pressurized volume is too expensive. Not big tractor things.

I think we'll be getting 90% of our calories from vats or tubes, though. Scales much better on a place like Mars.

That's right, pressurized volume will be at a premium.

Very long term, after we start terraforming Mars, there will be open fields in a low pressure CO2 atmosphere. Farmers will have to wear oxygen masks, but they won't need pressure suits. However, that could be thousands of years from now.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/18/2014 07:48 PM
Pressurized volume becomes linearly more difficult to build when it grows in size. Also if you want to use natural light instead of first transforming light into electricity and then back into light you don' want too thick walls that attenuate available light.

To grow biomass with plants you need at least temperatures near 20°C for efficient plant growth. That means you need liquid water at that temperature which requires some minimum amount of pressure. Easiest would likely be long stretched structures with quite limited witdth and height.

On the extreme side however I wonder if we could grow plants that provide their own pressure hull. Something like a cactus with quite strong outer skin. You just need to get the water inside and have an unpressurized greenhouse covering the area to keep it warm. It may take some genetic engineering for such a plant to grow and produce useful biomass but we may be able to do it sooner or later.

Keeping places warm is much easier on Mars than in cold places on Earth. It is the thick atmosphere that will suck the heat out. On Mars you only need a barrier to infrared. That could be an extremely thin plastic sheet.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 10/18/2014 08:11 PM
Nah, we'll be doing hydroponics because pressurized volume is too expensive. Not big tractor things.

I think we'll be getting 90% of our calories from vats or tubes, though. Scales much better on a place like Mars.

The future of fully synthetic food has been pitched since the 1950s and hasn't caught on for good reason.

Food must be much more then simple nutrition NASA learned this early in the space program.
It also must be enjoyable to eat as well as this is very important to the morale.

Morale is every bit as important as basic nutrition in the long term as it effects health.

Farming on Mars will likely involve lots of hydroponics or aeroponics early on along with aquaculture.

Some examples of what a Mars food system may look like.

https://www.youtube.com/watch?v=_Nfcat6jXBo

https://www.youtube.com/watch?v=84zh7XL15n8

The presence of plants and fish also will contribute to the habitat feeling like home vs sterile and foreboding.
Some plants may even be there mostly for decorative purposes outside of making O2.

Later on when there is use of Martian materials in building structures like large domes we may see more conventional looking farming practices and maybe even use of tractor like things working soil if that proves more cost effective.
Im talking about mycoprotein and single-celled protein with methane as a feedstock. Both are used on Earth today, one directly for human consumption and the other as animal feed (could be used for human consumption).

But consider that most of our staple crops are grown far away and are highly processed (in vats and tubes) to the point where they are indistinguishable from something from a vat.

Also, 10% of calories from fresh vegetables (and fish, as a delicacy) is not an insignificant amount by mass. Lettuce and tomatoes grow well in hydroponics but you have to eat a LOT of lettuce and tomatoes before you eat 200-300 calories' worth!
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/18/2014 10:24 PM
Would it be fair to say that the equatorial regions of Mars would be the most suitable region for agricultural production to be set up?

Or are there other regions more suitable based on other considerations (eg. availability of water)?
Title: Re: Scaling Agriculture on Mars
Post by: mr. mark on 10/18/2014 10:26 PM
Maybe we can get the SpaceX farmer to weigh in on this..... ;)
Title: Re: Scaling Agriculture on Mars
Post by: Vultur on 10/18/2014 11:49 PM
On the extreme side however I wonder if we could grow plants that provide their own pressure hull. Something like a cactus with quite strong outer skin. You just need to get the water inside and have an unpressurized greenhouse covering the area to keep it warm. It may take some genetic engineering for such a plant to grow and produce useful biomass but we may be able to do it sooner or later.


Plants growing at ambient Mars conditions might well be workable with arbitrarily good genetic engineering.

I think I'd go in the direction of making their metabolism work effectively at daily highs of single-digit degrees C (at which temperatures water can be briefly liquid at low elevations on Mars) and allowing them to melt their own water (as skunk cabbages can melt snow in spring on Earth) - I'm not sure if the biological pressure hull route could be made to allow the plant to collect CO2 from the atmosphere.

The energy budget for the melting is likely too much for a plant at Mars sunlight, but with this level of hypothetical genetic engineering, we can probably increase the efficiency of photosynthesis.
Title: Re: Scaling Agriculture on Mars
Post by: gbaikie on 10/19/2014 12:34 AM
Would it be fair to say that the equatorial regions of Mars would be the most suitable region for agricultural production to be set up?

Or are there other regions more suitable based on other considerations (eg. availability of water)?

Without any amount of terraforming, it seems the polar regions would best place to grow plants in a greenhouse- because of the availability of constant sunlight for 1/2 of a Mars year of  668 days- or 334
growing days of sunlight. But you would grow seasonally- not possible in winter.
And there would water available at surface. Maybe if one had nuclear power, one could mine water in winter and grow seasonal crops in other 1/2 of the year. Of course this only works for seasonal crops- if you want grow grapes it could more of problem.

But I think if found a lot of cheap water- ground liquid water, one could terraform by using the water. So if find cheap water in equator, terraform and grow plants at equator.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 10/19/2014 12:53 AM
Something like 31 degrees North latitude has the highest minimum amount of solar influx per day (i.e. the most sunlight in the "winter") on a flat or slightly inclined surface. So not precisely the equator.

http://systemarchitect.mit.edu/docs/cooper10.pdf
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 10/19/2014 01:18 AM
The reason I bring up vats/tubes for food production is that Biodome 2 attempted to produce all the food for its inhabitants from farming. They didn't make quite enough, it led to frictions within the group and eventually some of them started eating emergency rations, which was against the experiment's protocol. The lack of food probably also caused some of the other psychological/sociological problems with the team that ultimately contributed to the early ending of the experiment (second time around).

For this reason, it is critical that there be an abundance of basic sustenance to make sure morale doesn't end up in the toilet and someone decides to open up the airlock (which will be a much bigger problem on Mars than it was for Biodome 2). So while I support hydroponics and farming, in my opinion there should be some higher-productivity methods included so there's NEVER any question of lack of food (or breathable air or drinkable water).

And historically, settlements fail for three reasons: 1) starvation 2) disease and 3) attack by rivals.

Mars probably is either nearly or completely sterile at the surface, so native diseases are almost surely out (and wouldn't be adapted to Earth lifeforms, let alone mammals and humans specifically). All that you'd have to deal with are Earth-borne diseases. This is significant, but we know how to deal with them.

There are no native peoples on Mars, so attack by natives is out as well (as is /assistance/ from native peoples). You'd only have attacks from other colonies, which seems incredibly unlikely in the near-term since it'd imply total war happening on Earth (since colonies would surely need shipments of supplies from Earth, and the only possible way there wouldn't be an outcry from the international community due to an attack would be if there were total war on Earth, ala WWI or WWII).

That leaves starvation. So make sure you apply ALL of what we know of how to most efficiently and effectively produce calories (and protein) on Mars. That has to mean high-productivity foods like mycoprotein or single-celled bacterial mats fed straight from methane and ammonia or possibly algae grown in tubes (most efficient way to cover large areas on Mars with a minimum of pressure vessel structure).

No doubt you'd also want hydroponics as well, but it shouldn't be critical to the basic food supply.

You might even want BOTH systems in parallel to provide completely dissimilar redundancy and overlap. Probably want to grow potatoes, though, since they're so dang productive. Or at least have a plan to grow potatoes.

Also, Mars' dry, cold, sterile surface is a great way to provide long-term storage of food, effectively freeze-drying anything you put out there to the point that (if protected from dust and such) would probably be edible in a century. In this way, a colony with a solid productive surplus could provide several years' worth of backup food in a fairly straightforward manner.

But productive surplus is the key, probably the single most important thing that determines success or failure in a typical settlement. And nothing beats growing stuff in a vat or in tubes from that standpoint. Sure, we may prefer regular old farmers market fresh veggies and meats, but more important to establish productive surplus first.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/19/2014 01:32 AM
I first wanted to further elaborate on that previous idea of pure CO2 greenhouses. What if you tried a variant of the proposal for filling craters with SF6 breathing gas? What if instead of SF6, it was some other heavy gas that was healthy for crops? Couldn't that be used to turn craters into fertile vallies?

But separately, just regarding what was said about growing crops in ambient Mars conditions - is this realistically possible?

For instance, we know that there are extremophiles on Earth which can tolerate some ridiculous conditions. There have even been some bacteria discovered in the high upper atmosphere, as I recall (although that more recent report from the Russians about space barnacles or something hasn't been verified)

But so even if there are extremophiles that can tolerate ambient Mars conditions, does this mean that crops can be bred which can tolerate ambient Mars conditions?

It seems to me that if we can grow edible biomass in ambient Mars conditions, then the food problems of Martian colonists are as good as solved. In that situation, then you probably don't even need any enclosures, and can just start converting the soil to make it arable to your Mars-ambient vegetation.

But is it realistically conceivable that vegetation could be engineered to grow in Mars-ambient conditions?
If we can take all that we know about extremophiles, lichens, etc, and intensively breed them for Mars-ambient conditions, then could such a project succeed?

Is there anyone out there actually trying to do this? How expensive would it be to try this?


http://news.discovery.com/space/home-made-mars-habitat-tests-lifes-limits-110623.htm


http://www.americanscientist.org/issues/pub/2000/3/extremophilic-terraforming

"Redhousing":

http://www.asi.org/adb/06/09/03/02/093/redhousing.html
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 10/19/2014 01:43 AM
It may not be TOO hard to produce an enormous inflatable bubble for growing plants. Doesn't need to be very high pressure, maybe 1-2 psi (or even less, though you'd need a full spacesuit), but it'd protect the plants from the big temperature swings and could keep them warm with the right emissivity coating.

1 square kilometer greenhouse with an average height of 30m and a pressure of 1psi could be built using only 500 tons of high-strength material (specific strength of 1 GPa/(gram/cm^3) or higher... state of art UHMWPE, aramids, and carbon fiber can do better than that). You'd still want a pressure suit on, but for short-term survival (if you were acclimated very well, like an Everest climber), a forced oxygen mask would work. 1000 tons and you wouldn't need a pressure suit except for emergencies.

...of course, lower the height to just 3m, and you need an order of magnitude less material for a square kilometer (but you'll run into minimum-gauge issues with the thickness of the material, especially because the impermeable layer and any coatings will take up a lot more of your mass, proportionally).
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/19/2014 02:12 AM
What about in comparatively low-altitude depressions like Hellas Basin, where triple-point of water is believed to be possible?

Could those areas become a "mesopotamia" or fertile region with best conditions for agricultural expansion?

Just looking at the general shape/structure of cactus plants, their typical globe shape seems to suit the pressure hull idea:

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

(http://upload.wikimedia.org/wikipedia/commons/thumb/1/12/Singapore_Botanic_Gardens_Cactus_Garden_2.jpg/350px-Singapore_Botanic_Gardens_Cactus_Garden_2.jpg)

But they should be engineered to not have any spines, since there are no predators on Mars to require defense against. At least that might economize on wasteful metabolic output.

http://www.cactuscollection.com/info/cold.html

(http://www.cactuscollection.com/images/frozen_aloe.jpg)


http://www.windowsillcactus.com/cold_hardy_cacti.shtml

(http://www.windowsillcactus.com/images/fragilis.jpg)

Quote
Opuntia fragilis
fragilis

"Brittle Cactus"

Their habitat ranges from the south western states to Canada, and farther north than any other cacti in British Columbia. They have colonies into the eastern states as far as Michigan, and north all the way to the upper peninsula of Michigan. Their flowers are usually yellow, but maybe there are some rare magenta or white flowering plants too. The pads are small from half an inch to a few inches long, and depending on the colony visual spine texture varies slightly too. Plants form mounds from two to fifteen feet wide, and they remain close to the ground mounding few inches high. These cacti rarely produce seeds, and their main method of distributing themselves over a vast range of habitat is by stem propagation. Their pads are only slightly attached to one another and it's possible for pads to catch on passing wildlife then drop off in a new place. Pads will send down roots and generate a new plant allowing this plant to easily establish itself in new places without seeds. All cacti have the ability to grow new roots from their stems, and this species specializes in propagating itself this way. Some colonies thrive in areas with heavy rainfall and others require arid conditions. This is often considered to be the most cold tolerant cactus by any standard for survivors of extreme conditions.   



(http://www.windowsillcactus.com/images/polyacantha.jpg)

Quote
Opuntia polyacantha
polyacantha

"Starvation Cactus" or "Plains Prickly Pear"

This species lives in wide spread locations of the western states, and has habitat as far north as Canada. They grow from lower plains to medium high elevations in sparsely treed habitat with some grasses and rocky ground. They tend to grow in dryer climates and it is unlikely to find colonies outside of arid and semi arid regions. Their general visual texture is highly variable making them a plant suitable for study by anyone who wants to specialize in one species of Opuntia. They sometimes have tuberous roots, but their most noted habit is the lack of fleshy mass inside of the fruit to accompany the seed at maturity. They grow low to the ground and pile up their pads to form clumps a few feet across, but sometimes colonies may spread out more than five feet across. The spines of these cacti vary in color, and appearance may vary in density from thick to showing no spines . The pad size may vary, but usually pads are small from less than two to five inches across. They have a wide variety of flower colors like white, pink, magenta, red, chartreuse, and colors in the yellows sometimes with red centers. Some flowers of this species have different colored edges of their peddles. Many colonies survive in extremely hot and dry conditions while others grow where winters are long, cold and the snow piles high. They are true survivors of extreme climates and will tolerate different climate conditions depending on the specifics of their habitat.


(http://www.windowsillcactus.com/images/simpsonii.jpg)

Quote
Pediocactus simpsonii var. minor
simpsonii

"Mountain Cactus"

These cacti specialize in high altitude conditions and have some of the most interesting survival strategies of any cold hardy plant. They are small globular cacti with plenty of spines. They are visually distinct in the way tubercles line up around the stem creating spiral channels. When seeds drop from the top of the stem they can fall down the sides of the plants beneath the spines falling in a spiral path. Many seeds collect at the base of these plants as they grow where they may stay without germinating for the life of the plant. They seem to have plain looking flowers in photos, but if you ever see their pink to white flowers in person they are very intense. Perhaps they are some of the most beautiful and mysterious plants in the world. They are similar to other cacti which survive in extremely cold conditions in that they shrink before winter, and some of them can become almost flat to the ground. They also have some unique and interesting chemistry that happens inside the stems of these plants which sets them apart from other extreme cold survivors. Beneath the winter snow they create their own snow caves by using some sort of chemical method to melt the snow near the stems. From all of the cacti who are survivors of extreme habitats this one is very unique.
Title: Re: Scaling Agriculture on Mars
Post by: Vultur on 10/19/2014 07:05 AM
You might even want BOTH systems in parallel to provide completely dissimilar redundancy and overlap. Probably want to grow potatoes, though, since they're so dang productive. Or at least have a plan to grow potatoes.

That makes sense.

I do think Biosphere 2 probably gives us an overly pessimistic picture of how hard 'normal' agriculture in a largely materially-closed system would be due to over-complexity & some design issues. But use of some microorganisms makes tons of sense in a closed environment - Spirulina as protein source etc.

I've heard that a microorganism heavy diet could cause gout problems due to the high nucleic acid content, so it might *have* to be both types even before you factor in the psychological benefits of green plants and "real" food.

Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/19/2014 08:37 AM
But is it realistically conceivable that vegetation could be engineered to grow in Mars-ambient conditions?
If we can take all that we know about extremophiles, lichens, etc, and intensively breed them for Mars-ambient conditions, then could such a project succeed?

I am pretty sure it is not realistic. Sure plants can be engineered to survive. But for food we need a high rate of biomass production. And every plant that has a high growth rate needs at least improved temperature. Which can be quite easy. I have proposed domes before made of very thin very lightweight plastic. Coated on the outside to be UV-restant and IR reflecting on the inside. With the soil itself storing heat for the night it would be an extremely lightweight habitat.

Those plants won't necessarily be edible. As long as they produce cellulose they can be processed into other hydrocarbons or be used to feed funghi.

But in all likelihood algae are the most efficient source of biomass. They have a very high conversion rate light to biomass and pipes or hoses to provide necessary pressure are easy enough to manufacture. So scaling them up to any required size is not difficult. Such setups will quite likely be competetive with conventional agriculture even on earth. Much more so on Mars.

Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/19/2014 08:41 AM
I've heard that a microorganism heavy diet could cause gout problems due to the high nucleic acid content, so it might *have* to be both types even before you factor in the psychological benefits of green plants and "real" food.

I have read about problems with kidney and bladder stones. The problems can be solved by hydrogenating the produce for consumption.

Oils from algae also will need processing to make them suitable for human consumption.

But both are very well known processes and are used already in the food industry today.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 10/19/2014 12:20 PM
Everyone says that hydroponics will be the main way to grow food on Mars - but will it always be?

No they don't.

We had a long discussion on this section of the forum and, arguably, it seems the favourite technologies are:

- Direct synthesis of food from organic chemicals.
- Algae grown in photo reactors (which you could say is a form of hydroponics)

If these can't be converted into anything yummy, then they can be fed to chickens and fish (so some hydroponics).

Algae plus chickens is more efficient in terms of land and light use than potato.

There's also a role for greenhouse "salad vegetables" - (not sure the collective term) like tomatoes, which have a very hight yield because they're mainly water.
Title: Re: Scaling Agriculture on Mars
Post by: Nilof on 10/19/2014 05:11 PM
One thing to keep in mind is that the greenhouses do not necessarily have to be pressurized enough for humans. They only need to be pressurized enough for plants. So agricultural space is likely to be easier to build than living space. With that said, you could certainly have gardens/orchards in your living space as well.
Title: Re: Scaling Agriculture on Mars
Post by: IslandPlaya on 10/19/2014 09:56 PM
One thing to keep in mind is that the greenhouses do not necessarily have to be pressurized enough for humans. They only need to be pressurized enough for plants. So agricultural space is likely to be easier to build than living space. With that said, you could certainly have gardens/orchards in your living space as well.
Nonsense! One of the key things that can't be automated entirely is growing food.
Shirt-sleeve access to it will be essential at habitat pressure.
Everything on automatic and apple trees in your apartment is a bit silly.
The first people on Mars will be farmers and bloggers and reality tv stars...
Title: Re: Scaling Agriculture on Mars
Post by: enkarha on 10/20/2014 12:11 AM
What's the diffusion rate for a dome that doesn't have a bottom?  That is, we dig a nice deep parallel trenches, put a half-tube of plastic or what have you over the top of the area, edges in the trenches, anchor it down well, fill the trench up with some sort of concrete, and blow her up to maybe an armstrong limit or two? Then we continuously pump in a nice inert gas/CO2 mixture at the rate it leaks out. It ain't elegant, and you don't want people in there all the time, but  it might be fast and to build, and give roots indefinite access downwards. Or is this what people are talking about when they say greenhouses &c.

EDIT 1: Okay, did some basic but possibly very wrong calculations. Using Fick's law, and a pressure of about 20 kPa (30% O2, 30% N2, 30% Ar , 10% H2O)*,  through a 3 meter deep barrier of sandy loam**, the diffusion flux is about 1.3*10-7 kg*m-2*s-1. That's about 1 kilogram lost per 100 m2 greenhouse per day. I'd say that's pretty darn good. The temperature differences and pressure differences(Fick's law accounts for concentration, not strictly pressure) and true soil characteristics, &c. might do something, but I'm not qualified there. Many many more assumptions made - concentration of gas at bottom is 0,

*: atmosphere composition, pressures roughly(more O2) pulled from http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050182976.pdf

**: Diffusion coefficient for sandy loam taken as high value from
http://onlinelibrary.wiley.com/doi/10.1111/ejss.12056/abstract
(Converted units, etc)

I just realized that the air pressure is going to want to pull the greenhouse right out of the surface. The concrete itself might do a good job at resisting some of that force,  but only enough that the tube can be about 2.5 meters wide if the concrete's a meter thick and 3 deep. So basically, good anchoring will be needed.
Title: Re: Scaling Agriculture on Mars
Post by: gbaikie on 10/20/2014 02:08 AM
What's the diffusion rate for a dome that doesn't have a bottom?  That is, we dig a nice deep circular trench, put a half-dome of plastic or what have you over the top of the area, edges in the trench, anchor it down well, fill the trench up with some sort of concrete, and blow her up to maybe an armstrong limit or two? Then we continuously pump in a nice inert gas/CO2 mixture at the rate it leaks out. It ain't elegant, and you don't want people in there all the time, but  it might be fast and to build, and give roots indefinite access downwards. Or is this what people are talking about when they say domes?

Forget digging, and find a crater. On Mars they are all over the place, unlike earth. On Earth we example of small crater- and this related to a relatively small but dense and strong iron rock hitting. Less dense, and strong and same size rock would blow up about 30 km above the ground. Or Earth has dense atmosphere.
Meteor Crater is "is nearly one mile across, 2.4 miles in circumference and more than 550 feet deep. " So get smaller crater, and one can get lots of smaller craters on Mars because it has thin atmosphere. So say 100 meter or less in diameter- even small as that one the bouncing airbag ended up putting a Mars rover in.
Probably good to find one which has excavated down to hard rock [bed rock]. So say 20 -30 meters deep.
Cover it will plastic. And fill it with water. Under 10 feet of water on earth the pressure is about 1/3 of a Earth atmosphere. On Mars it's about 1/3 of 1/3rd [Mars has 1/3 gravity] of Earth's atmosphere.
Or 1/9th of 14.7 psi is about 1.6 psi. And 5 feet down is half of that.
With plastic assume one might double [or more] Mars atmospheric pressure- which about 1/100th of Earth
or .147 psi. So say under the plastic it's .3 psi, and 5 feet under water it's .8 + .3, giving 1.1 psi.

So one could do lot's of things. Have hemisphere of 12' sphere. So 6 feet high. Submerge it 5 1/2 feet under the water. So 12 foot diameter concrete with bubble on top, and 1/2 foot above the water.
So in it, you need about 1 psi to keep it inflated. And most of plastic bubble does not need to be strong- Sarah wrap is strong enough. To enter it, one can swim under it and enter thru a open hole. Or make air lock on top of it. So say 4 foot disc of hard clear plastic, which you attach a tube with two hatches- and small pump that removes and adds air. Have a bit stronger plastic than Sarah wrap attached to hard disc adding some strength and flexibility. So hard plastic is 4 foot ring, with say 3 foot diameter cylinder which is 6 feet tall- tube could 1/4" thick walls- have straps/rungs to climb down. Two low pressure hatches to go thru to get in the bubble. One have something like that for plants.
For living area, have it in deeper water- have depression already there or blast a hole before you start everything.
So living areas also don't need much in terms of structure strength. They have to be anchored or have enough ballast for neutral buoyancy. And they get a lot radiation shielding. No dust problem- though one could get wet floors.
One could have large windows and have good visibility and daylight.

Edit And more you put under water, more water you displace [need less water- per volume used]. And
one will get a constant thermal environment- or you achieved global warming- which mostly about balancing daytime temperatures with nighttime temperature. A really strong "greenhouse effect" - night temperature will not less than a degree or two from daytime temperatures.

Edit. One does really need domes or curves- because there is not much structural stress- so it can be more box like- in terms of the walls. And submarine depths are 3 deeper on Mars as compared Earth. Or scuba depth is also 3 times deep and you have travel 3 times the depth to get same amount of bends as you can get on Earth.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/20/2014 05:29 AM
Well, if you use a crater, that then reminds me of what I said before - can you fill it with some heavy gas that won't easily dissipate? There's been plenty of discussion about sulfur hexafluoride (SF6) as a breathing gas for humans which is heavy enough that it could be used to fill up craters, etc.  But if you're talking about a heavy gas that's meant to be tolerable to plants, then maybe you've got more choice on what kind of gas you can use?

Does anybody know of any candidates? How about some heavy hydrocarbon gas?
Title: Re: Scaling Agriculture on Mars
Post by: Nilof on 10/20/2014 02:42 PM
Nonsense! One of the key things that can't be automated entirely is growing food.
Shirt-sleeve access to it will be essential at habitat pressure.
Everything on automatic and apple trees in your apartment is a bit silly.
The first people on Mars will be farmers and bloggers and reality tv stars...

You can do the key setup parts in a higher pressure hab where you can do shirtsleeve stuff, and move the whole setup to a low pressure part for growing. Combining "high pressure" and "lots of sunlight" is going to be very hard on Mars. A greenhouse is a lot easier to build if it doesn't have to be highly pressurized, and you're going to need a lot of growing space if you want to make the colony self-sufficient.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/20/2014 03:27 PM
I don't really see a conflict. Plants and water at the right temperature will likely require around 3 psi, or 20% of earth sea level pressure. That is pretty low for building greenhouses and people can work under those conditions using only oxygen masks.

Plus the bulk of calories will come from easily grown algae. Greenhouses are for tomatoes, cucumbers, bell peppers, herbs, garlic, onions, all fast growing, providing important parts of the diet, but not so many calories from a relatively small area.

As soon as the colony can afford it, add coffe, tea, and some fruit.

Build them in a way that they don't fail catastrophically, when they fail. Compartmentalize them, so people should have a minute or two to get into the next compartment before the pressure drop becomes lethal.
Title: Re: Scaling Agriculture on Mars
Post by: sghill on 10/20/2014 04:56 PM
Plus the bulk of calories will come from easily grown algae.

Speaking of.  I've got a friend who has pretty much given up on food (I'm not making this up), and now subsists on "soylent" nutrition drinks that show up from Amazon every couple of weeks.

http://www.independent.co.uk/life-style/food-and-drink/features/soylent-could-a-quick-slug-of-nutritionally-engineered-sludge-ever-replace-the-leisurely-meal-9804885.html

I can see the value for marathon gamers and hyper-kinetic types who don't want their productivity ruined by that whole "living life" thing.  The concept is interesting, but no thanks!  There are some serious physiological consequences of having a diet with limited source input variability as well- such as cavities, pygmy-ism, and malnutrition in general.

3-D printing of algae and soy-based foodstuff could make for some more interesting options using the same base materials though!  http://www.theverge.com/2014/1/24/5342180/watch-this-3d-printer-make-pizza-fit-for-astronauts
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/20/2014 05:36 PM
I am not proposing energy drinks or 3D printing of food. There would likely be different algae for carbohydrate production and oil production. Protein may come from agae or bioreactors with methane fed bacteria.

The source materials will be separated into starch and oil, and protein. Those three components, with designer sources for protein with desired properties, can then  be processed into basic foods very similar to what we are used to. Flour is starch with added  proteins with certain proteins. Oil and proteins can be processed to a milk substitute or egg substitute. Flour with egg substitute gives bake products, noodles. Milk substitute will be the base product for all kinds of milk products like yoghurt, cheese.

The food on the table will closely resemble what we eat on earth, just not sourced from wheat, rye, corn, rice, milk, eggs.

With some more processing it will be possible to produce reasonable substitutes for meat. Initially maybe just minced meat, later something more similar to the steak or pork chop we are used to.

Food technology is already advancing fast into that direction. It does not need too much advancement to get to the scenario I am describing.
Title: Re: Scaling Agriculture on Mars
Post by: Vultur on 10/22/2014 04:31 AM
Well, if you use a crater, that then reminds me of what I said before - can you fill it with some heavy gas that won't easily dissipate? There's been plenty of discussion about sulfur hexafluoride (SF6) as a breathing gas for humans which is heavy enough that it could be used to fill up craters, etc.  But if you're talking about a heavy gas that's meant to be tolerable to plants, then maybe you've got more choice on what kind of gas you can use?

Does anybody know of any candidates? How about some heavy hydrocarbon gas?

There are just not many very heavy gases. Heavy hydrocarbons aren't gases (unless there is some weird exception); boiling points increase as you add carbon atoms. Butane and butene are gases at room temperature, pentane and pentene have boiling points a little above room temperature, above that it's not even close.

Sulfur hexafluoride is probably about as good a candidate as you'll find. Xenon is a very rare element and has more intense narcotic/anesthetic properties than SF6. (Most gases have this to some degree, but with e.g. nitrogen it only becomes a problem at well above atmospheric partial pressure - the nitrogen narcosis or 'rapture of the deep' experienced by divers - while xenon has actually been used as an anesthetic. According to this source (http://www.ncbi.nlm.nih.gov/pubmed/8175542) SF6 is 8.5x as narcotic as nitrogen, while xenon seems to be 25.6x as narcotic (http://www.biomed.cas.cz/physiolres/pdf/56%20Suppl%201/56_S39.pdf).

Selenium, tellurium, and tungsten hexafluoride are totally unsafe (toxic/extremely corrosive).


What about in comparatively low-altitude depressions like Hellas Basin, where triple-point of water is believed to be possible?

It definitely does occur (though briefly); Curiosity weather data show pressures consistently above the triple point of water, and daily high temperatures sometimes rise above the triple point (Sol 737, the most recent on the http://marsweather.com/data site, shows 3 C high, -74 C low, 777 Pa pressure) And the ground temperature in the sun around noon/early afternoon should be higher than the air temperature.

However, the partial pressure of water vapor in the atmosphere is near zero, so even during these brief
times liquid water would evaporate, though not boil.

The best hope of "Mars-adapted" higher plants I think would be using thermogenic cells (like skunk cabbage uses to melt snow in spring) in the roots to melt subsurface ice where the pressure of the soil/regolith would keep it from evaporating as quickly. But this would not provide that much water (thus slow growth) and would require very advanced genetic engineering.

Quote
Just looking at the general shape/structure of cactus plants, their typical globe shape seems to suit the pressure hull idea

Since plants must exchange gas with the atmosphere to get CO2 (and excrete O2) I don't think the pressure hull idea is very workable. They would have to somehow pump CO2 in through the stomata against a pressure gradient.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/22/2014 06:35 AM
Since plants must exchange gas with the atmosphere to get CO2 (and excrete O2) I don't think the pressure hull idea is very workable. They would have to somehow pump CO2 in through the stomata against a pressure gradient.

You are right. I completely forgot about the gases. The colonists would not only need the biomass, the oxygen too is needed. So any production of biomass would have to be enclosed and a means of extracting the oxygen is part of the system.

Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 12/29/2014 02:43 PM
Mars has some atmospheric pressure, so pressure for plants might not be a problem.  The equator on Mars is about 32 degrees F, so cold tolerant plants could grow at the equator like in the tundra areas of earth.  Reindeer eat this stuff, and it could be harvested mechanically and fed to Reindeer for meat.  They might could even grow cold tollerent wheat or corn genetically developed.  All this could grow outside greenhouses as long as water was available.  Plants could be harvested by pressurized electric tractors. 

I also know of a company locally that has 20 acres under greenhouses.  They grow starter veggatable plants, and flowers for sale at places like Lowe's and Home Depot.  It is not impossible to build whole cities under greenhouses connected by covered trailways for carts to move on.  Using iron, aluminum, or other resources found on Mars, structures could be built for colonists on a continuous basis.  Farming expanded, resource exploration, structure manufacturing could all keep colonists busy for years.  Once something is found or could be made in the lower gravity of Mars that could be traded with Earth, then they could eventually become self sufficient.  Mars could become the launching point for further exporation in the asteroid belt, Ceres, or the moons of Jupiter and Saturn. 

It took almost 200 years for America to grow to the point of getting independence.  It may take the same for Mars.  Continuous colonization, building, expanding to become self sufficient, then launching further outward exploration. 
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 12/29/2014 03:22 PM
Mars has some atmospheric pressure, so pressure for plants might not be a problem.  The equator on Mars is about 32 degrees F, so cold tolerant plants could grow at the equator like in the tundra areas of earth.  Reindeer eat this stuff, and it could be harvested mechanically and fed to Reindeer for meat.  They might could even grow cold tollerent wheat or corn genetically developed.  All this could grow outside greenhouses as long as water was available.  Plants could be harvested by pressurized electric tractors. 

I also know of a company locally that has 20 acres under greenhouses.  They grow starter veggatable plants, and flowers for sale at places like Lowe's and Home Depot.  It is not impossible to build whole cities under greenhouses connected by covered trailways for carts to move on.  Using iron, aluminum, or other resources found on Mars, structures could be built for colonists on a continuous basis.  Farming expanded, resource exploration, structure manufacturing could all keep colonists busy for years.  Once something is found or could be made in the lower gravity of Mars that could be traded with Earth, then they could eventually become self sufficient.  Mars could become the launching point for further exporation in the asteroid belt, Ceres, or the moons of Jupiter and Saturn. 

It took almost 200 years for America to grow to the point of getting independence.  It may take the same for Mars.  Continuous colonization, building, expanding to become self sufficient, then launching further outward exploration.

Martian atmospheric pressure is about 1% or less than that of Earth. In some previous posts, it was suggested the pressure would need to be anywhere from 1 to 3 psi or about 7 to 20 times greater than the martian atmosphere for plants to grown in a CO2 atmosphere. Low pressure green houses with air compressors would be not be hard to build.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 12/29/2014 04:48 PM
Even a 1 acre greenhouse on earth could provide enough food for a family of 4 which includes rabbits or chickens.  So it is not impossible to grow food. Tilipia can be grown in a greenhouse pool and provide a lot of protein per acre.  I even predict farming in the future on earth will be done in greenhouses.  Smaller animals and chicken as well as fish can be also.  One acre of wheat can provide on earth one family with enough bread for a year.  Two to three crops a year could be grown in a greenhouse.  Food will not be impossible on Mars, water is available.  Nitrogen may be the kicker and would might be in short supply.  Animals could provide the fertilizer over time.  Homes could be built with gravity fed water tanks above them for radiation protection.  The water could also double as heat storage at night.  Waste water to feed the plants.  Nothing is beyond existing technology.  New ideas, technologies, food substitutes, etc, developed on Mars could benefit earth. 
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 12/29/2014 05:11 PM
I am alergic to soy and cow's milk, so I have to use almond milk.  I know soy has a lot of protein, but maybe other sources of protein can be made.  Like I said nitrogen is going to be the problem with Martian plant growth.  So some small animals or fish will be needed to provide a source of nitrogen for plants to grow as well as human waste. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/30/2014 09:05 AM
I am alergic to soy and cow's milk, so I have to use almond milk.  I know soy has a lot of protein, but maybe other sources of protein can be made.  Like I said nitrogen is going to be the problem with Martian plant growth.  So some small animals or fish will be needed to provide a source of nitrogen for plants to grow as well as human waste.

To grow fish you need protein food first, that gives them the nitrogen. Fortunately the martian atmosphere contains a lot of nitrogen. The gas will be a byproduct of fuel ISRU. Nitrates can be produced unsing the Haber Bosch synthesis.

Just yesterday I have seen a report on local TV about an new company that grows both fish and use the nutrient rich water from the fish to grow a large variety of vegetables, keeping the water in a closed circuit between fish tanks and plant greenhouse. A method that would be very suitable for a closed circuit ecology on Mars.

Proteins for feeding the fish could be produced with bacteria that feed on methane with added nitrates and trace elements. A method that is already approved for producing animal feed in the EU.

Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 12/30/2014 07:11 PM
I am alergic to soy and cow's milk, so I have to use almond milk.  I know soy has a lot of protein, but maybe other sources of protein can be made.  Like I said nitrogen is going to be the problem with Martian plant growth.  So some small animals or fish will be needed to provide a source of nitrogen for plants to grow as well as human waste.

To grow fish you need protein food first, that gives them the nitrogen. Fortunately the martian atmosphere contains a lot of nitrogen. The gas will be a byproduct of fuel ISRU. Nitrates can be produced unsing the Haber Bosch synthesis.

Just yesterday I have seen a report on local TV about an new company that grows both fish and use the nutrient rich water from the fish to grow a large variety of vegetables, keeping the water in a closed circuit between fish tanks and plant greenhouse. A method that would be very suitable for a closed circuit ecology on Mars.

Proteins for feeding the fish could be produced with bacteria that feed on methane with added nitrates and trace elements. A method that is already approved for producing animal feed in the EU.

It's called "Aquaponics" from "hydroponics+aquaculture" as a combined system :) There are several groups out there working towards "closed" (beside natural inputs) systems using algae as feedstock for such systems. Some of the archives for the S&S-Aquaponics forums have information on various in-loop fish feeding systems if you've got the time to look them up. (All my stuff is hard-copys) There were some folks who were working on a plant-and-fish-waste product recycling concept for food/fertilizer for the system but I don't have much more than outlines on that.

Aquaponics has been done with systems that both mono-culture as well as multi-culture for both aquatic and plant types with good success.
Modular, multi-node systems seem to work the best with mid-level rather than "high-intensity" systems having the best maintenance and operations records. And yield quatlity for both products is pretty high over any type of "soil" or even a straight hyrdoponics system in most cases.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 12/31/2014 10:02 PM
Tilipia are plant eaters and eat algae when young.  They are very fast growers and from birth to eatable size is only about 4 months.  Problem is they can't survive when the temperature is below 40 degrees F.  Their waste can produce nitrogen, and their bone and other wastes can be used as fertilizer.  One would get tired of tilipia all the time so rabbits and chickens might be a necessary for other sources of protein.  I think grains would require the most space. 
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 01/02/2015 06:48 PM
Catfish and trout also can be raised in the same sorta tanks.
Goats also can be useful and act as a garbage disposal for crop waste.

Of course once you get more people you can build bigger habitats and start raising plants and live stock that require more space.
Once you have tens of thousands of people you have the man power to build massive projects on the scale of large stadiums in fact construction may be the main vocation for many early Mars colonists
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/11/2015 02:20 AM
My first degree, a 5 year degree equivalent to MSc was in Agronomy and my final project/thesis was on a hydroponic tomato greenhouse. It is interesting to read comments on something I specialized before I went into remote sensing. First of all by definition hydroponics is a system where the nutrient come from the liquid phase rather than the soil, until we can get an entire soil ecosystem on Mars all agriculture will be hydroponics. If you want to see areas with significant greenhouse production just look up Ierapetra or Campo de Almeria on Google Earth you will see entire valleys covered in greenhouses. Hydroponics was originally adopted commercially in the Netherlands some 50 years ago when the soils inside greenhouses became too saturated in pests to allow the use them for agriculture, hence they decided to adopt the use of artificial substrates for plant growth as had the US Navy done in the Pacific in WWII in desert islands. The issue with artificial substrates though is that every 3 to 7 years they need to be disposed of, due to phytosanitary or micronutrient exhaustion reasons.

Plants require some 20 or so elements to survive, most as micronutrients but C,H,O (derived from air) and N,P,K (from roots) are macronutrients. Fe falls inbetween, too big for micro but too small for macro. A major limitation for all agriculture in Mars will be the provision of N in plant available form, either we need to bring the synergetic microbes that reduce Nitrogen to NO3 in the or build a factory that produces N fertilizer. P, K, Fe can be more easily extracted and turned water soluble from appropriate soils, the micronutrients can be added in the substrate.

Fixing low level lighting does not require genetically engineering plants, in the constantly overcast Netherlands there is commercial greenhouse production in Mars-level lighting conditions, all you need is artificial lighting. Artificial lighting and shading is also desirable for another reason: photoperiodism. Many plants species will move from the vegetative to the flowering stage only if there is an appropriate length of day and night. The big elephant in the room not mentioned so far is heat demand: the typical greenhouse has three times the heating demand of a house the same size, after all its covering material is optimized for transmisivity of solar radiation, not hear retention. While there are several cold hardy edible plants, especially in tundra/taiga ecosystems, it is best to keep temperature in the order of 20-30 degrees C because metabolism is faster. The specific temperature depends on the plant but be aware that C3 plants (and most edible plants are C3 plants) actually saturate productivity ca 20-25 degrees and for a radiation level while C4 plants metabolize and photosynthesize faster in higher temperatures and solar radiation.

Also all greenhouses on earth are quite airtight when doors and windows are closed to the point that if you do not open a window within a couple of hours after sunrise they will consume all CO2 and cease photosynthesis. We will need some way to pump in CO2 from the ambient air outside the greenhouse without dropping the temperature excessively. While I never read it I would like to point to the MIT study on the Mars One project, without removal of O2 created by the plants the colonists will die of oxygen poisoning in a couple of months.

Design of the agricultural system of any future colony is something that also depends on the caloric and nutritional needs of the colonists. You will definitely need some sort of animal or at least mushroom food source because vitamin B12 is not produced by plants. Hydroponics is one of the most efficient methods to produce nutrients per area, while horticultural crops produce far higher nutrients (be they proteins, carbohydrates or fat) than major crops (such as wheat or rice) per area. Robots cannot replace the farmer or the agronomist yet, especially in greenhouses, otherwise they would have already done so in Europe where there is a farm labor shortage. If my memory does not fail me the ratio for a high tech fertigated greenhouse is about 1 worker per 1000 m2 of greenhouse space. Robotics might work will with plants like lettuce that are short and mostly require harvest, but if we are talking about tomatoes or cucumbers which require tying up the stalks, pruning and other such activity we need people.

Setting the first farms on Mars looks quite boggling. Nutritionists need to calculate caloric requirements of the colonists and suggest a diet. Then in cooperation with agronomists they need to size the required growing space for the plants, which in turn will lead to labor requirements. Then agronomists need to size the nutrient requirements of the plants and in turn size appropriate facilities to provide the fertilizers. The first colonists to the US could get their nutrients from the soil ecosystem, Mars does not have one not does it even have nitrogen fixing bacteria to the best of our knowledge. Pollinators are another thing they will eventually need, but let's say that the first colonists use self pollinating plants. In any case modern intensive hydroponic production requires chemical fertilizers. Then after plant biomass starts getting produced it would be best to also some sort of animals eating what is not edible or palatable to people, which in turn gets into all sorts of issues of genetic diversity since animal productivity drops with inbreeding. Human and animal waste will get recycled to the plants, after all some 70% of nitrogen people and animals eat is excreted but that will also require some design.

A closed loop agricultural ecosystem is just daunting. The first Mars One colonists (if they make it to Mars) should be best all the food they need until the first resupply mission 26 months later while still setting the ecosystem. This however in turn creates another problem: is there shelf stable nutritionally complete food out there capable of lasting the 6 months transit and 26 months to resupply? If we resupply robotically outside the opposition opportunities, does food exist able to survive the radiation environment of the trip and arrive nutritionally complete or are the Mars colonists headed for space scurvy? I am not saying it is impossible, just daunting
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/11/2015 07:08 AM
@AegeanBlue

Very good post, thanks and welcome to the forum.

Many things one could reply to. I chose only few.

It is not that hard to keep the greenhouses warm. The martian atmosphere is near vacuum and will not transport heat the way the earth atmosphere does. As it is a greenhouse that takes sunlight in and stops infrared from escaping it may be necessary to implement methods to dispose of excess heat.

The effect of radiation is often overestimated because there is so much talk about it. While higher than recommended exposure for humans it is actually very low. Nutrients are not at risk.

A question on lighting. Is light used in greenhouses to increase yield or is it mainly to extend daylight hours to get plants into growth phase early, when the day is still short? On Mars early settlements would be near the equator, where days are quite near to 12 hours day, 12 hours night. That should be enough for the needs of plants. Maybe reflective mirror sheets can augment light level if required.

Edit: fixed typo
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/11/2015 07:12 PM
@AegeanBlue
It is not that hard to keep the greenhouses warm. The martian atmosphere is near vacuum and will not transport heat the way the earth atmosphere does. As it is a greenhouse that takes sunlight in and stops infrared from escaping it may be necessary to implement methods to dispose of excess heat.

Excessive heat inside the greenhouse is a problem that happens in Mediterranean climates from @ around March to the end of the growing season, whenever that is. The greenhouse can get to 40+ C plus when the outside temperature is 20+ AND there is strong sunlight. I doubt we will find this kind of condition in Mars but you are right, vacuum is great insulator. Then again despite the popular misconception the main heating effect inside a greenhouse is not that glass does not allow IR to leak, it is that we do not allow air to circulate with the environment. Glass will stop IR from leaking but glasshouses are maybe 5% of all greenhouses worldwide, PET which is what 80% of greenhouses are covered by is transparent to IR to the point that an unheated greenhouse at night can be cooler than the ambient temperature outside. Also as temperature drops relative humidity rises inside the greenhouse to the point that moisture condenses in the inner cover surface, something both desirable in that water reduces IR leakage and undesirable in that high humidity increases susceptibility to fungal diseases. I would be surprised if there is a cooling need at a Martian greenhouse and I think it could be easy to solve by pumping concentrated cold Martian air.

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The effect of radiation is often overestimated because there is so much talk about it. While higher than recommended exposure for humans it is actually very low. Nutrients are not at risk.

I am not worried about the health of plants, I am worried about nutrition. The reason we prefer to eat fresh rather than processed food is that processing destroys some of the complex organics that are necessary for human well being such as vitamins. Irradiation is an accepted process (granted, it is illegal in some countries) to preserve food but dosage is under strong limitation. What would the result of Mars travel cosmic irradiation on food? This would be a great topic for a thesis or dissertation.

Quote
A question on lighting. Is light used in greenhouses to increase yield or is it mainly to extend daylight hours to get plants into growth phase early, when the day is still short? On Mars early settlements would be near the equator, where days are quite near to 12 hours day, 12 hours night. That should be enough for the needs of plants. Maybe reflective mirror sheets can augment light level if required.


Both. Dreary northern Europe does not have sufficient lighting in the winter for the subtropical vegetables grown in the greenhouses, so they have lights. It is only though in northern Europe (perhaps Canada?) that artificial lighting is used to increase photosynthetic activity. Lighting and shading is used all over the world to grow off season crops that require specific day and night length to change phenological stage. If you have chrysanthemum in the winter, no matter what temperature you keep the greenhouse on it will not flower, it requires long days to flower. Seed companies have been creating day-length neutral varieties of major, but it is definitely better to design the greenhouse with artificial lighting anyway. Do we really want production to stop because a planet wide dust storm comes along and drops incoming radiation to pathetic levels, below what the plant needs to keep growing?

While some effects on the seeds can be overcome through vernalization, plants need their proper GDDs and day lengths to go through an entire cycle. It is best to select species for food productivity even if it means artificial lighting and day length control than to select for day length and low radiation, let's not forget what colonists can't grow locally they need to import from Earth.

If the first Mars trip is to stay there for a year rather than 30 days they need to grow their food rather than carry all of it which also means though that landing site must also be selected based on P and K rock richness, so as to provide local fertilizer. My thinking is that just considering how had it is to set up a farm without a biosphere, the first Expedition should be a 30 day type excursion with food for all 30 days but still have someone dedicated to setting up a farm and do grow something fast and edible these 30 days. By setting up a farm I mean setting up fertilizer production facilities, habitats, air pumps etc. When the second expedition lands they should start using the facility set up during mission 1 and plant a crop on day two to provide food, but still bring enough food for their entire duration. It would be after expedition 2 proves Mars farmable that they should forgo bringing all the food necessary. I am ambivalent if expedition 2 should be a 30 day or one year mission, but expedition one should definitely be a 30 day mission

BTW I am familiar with PLANTS, I used it for my dissertation
Title: Re: Scaling Agriculture on Mars
Post by: gbaikie on 01/11/2015 08:49 PM
Quote
A question on lighting. Is light used in greenhouses to increase yield or is it mainly to extend daylight hours to get plants into growth phase early, when the day is still short? On Mars early settlements would be near the equator, where days are quite near to 12 hours day, 12 hours night. That should be enough for the needs of plants. Maybe reflective mirror sheets can augment light level if required.

Quote
Both. Dreary northern Europe does not have sufficient lighting in the winter for the subtropical vegetables grown in the greenhouses, so they have lights. It is only though in northern Europe (perhaps Canada?) that artificial lighting is used to increase photosynthetic activity. Lighting and shading is used all over the world to grow off season crops that require specific day and night length to change phenological stage. If you have chrysanthemum in the winter, no matter what temperature you keep the greenhouse on it will not flower, it requires long days to flower. Seed companies have been creating day-length neutral varieties of major, but it is definitely better to design the greenhouse with artificial lighting anyway. Do we really want production to stop because a planet wide dust storm comes along and drops incoming radiation to pathetic levels, below what the plant needs to keep growing?

While some effects on the seeds can be overcome through vernalization, plants need their proper GDDs and day lengths to go through an entire cycle. It is best to select species for food productivity even if it means artificial lighting and day length control than to select for day length and low radiation, let's not forget what colonists can't grow locally they need to import from Earth.

If the first Mars trip is to stay there for a year rather than 30 days they need to grow their food rather than carry all of it which also means though that landing site must also be selected based on P and K rock richness, so as to provide local fertilizer. My thinking is that just considering how had it is to set up a farm without a biosphere, the first Expedition should be a 30 day type excursion with food for all 30 days but still have someone dedicated to setting up a farm and do grow something fast and edible these 30 days. By setting up a farm I mean setting up fertilizer production facilities, habitats, air pumps etc. When the second expedition lands they should start using the facility set up during mission 1 and plant a crop on day two to provide food, but still bring enough food for their entire duration. It would be after expedition 2 proves Mars farmable that they should forgo bringing all the food necessary. I am ambivalent if expedition 2 should be a 30 day or one year mission, but expedition one should definitely be a 30 day mission

BTW I am familiar with PLANTS, I used it for my dissertation

I would not suggest 30 day stay. But if want short duration on the surface Mars you pick the southern polar region and get more sunlight on Mars as compared to anywhere on Earth.
http://ccar.colorado.edu/asen5050/projects/projects_2001/benoit/solar_irradiance_on_mars.htm
"The South Pole has a higher seasonal maximum than the North Pole because southern summer occurs near perihelion.  Obviously, both solar powered systems and plants would not thrive all year long near the poles, however the seasonal variations near the equator are small and thus indicate the most likely latitudes for utilizing solar irradiance on the Martian surface.  "

The graph at above reference shows higher average yearly solar irradiance of over 250 watts. And get 250 watts at about  30 degree south, and for year average that is better than most places on earth.

Or Kansas gets about 5000 watt per day on average per year. And divide by 24 is 208 watts. Of course Kansas during summer has a higher per day solar irradiance.
But Mars summer at poles is 24 hours of sunlight and in terms of available 24 hours of sunlight on Earth [polar regions] one gets more sunlight per average hour on Mars.
Or Alaska is known for spectacularly growing season [though it's a very short period of time]. And Mars south pole would similar but a much longer period of time as Mars year [or a Mars summer] is quite a bit longer.
But if staying for years, it seems somewhere around 30 degree South latitude is best and could be that late spring and early fall at 30 degrees is better for growing plants than during summer- because you have longer daylight as compared to at equator [though it's shorter in winter]. On perfect sphere of planet and circle of orbit one gets equal amount of sunlight [1/2 day- regardless of poles or equator] but local terrain and orbital position have give more hours of sunlight per year and more solar irradiance. Or somewhat related to "southern exposure" in terms farming in Northern Hemisphere on Earth.

An in article above it refers to PAR [Photosynthetically active radiation]. And in terms of Earth, here another article:
https://www.agronomy.org/publications/aj/abstracts/76/6/AJ0760060939
"In the semiarid climate near Fresno, CA, the daily photosynthetic photon flux density (PPFD) in units of µmol m−2 was 2.04 ± 0.06 times the solar irradiance (SI). The daily irradiance within the PAR waveband (photosynthetic irradiance (PI), 0.4 to 0.7 µm) was estimated to be 45% of the daily solar irradiance. "

So Fresno has average of about 6000 watts per day [250 watt]. So in terms useful sunlight: 112.5 watts.
And in first article it shows that is varies quite a lot depending dust levels.

I would say roughly on Mars one has dust problem and Earth one has cloud problem. And Mars one could terraform so as to reduce dust levels, but on Earth one can't really do anything about the clouds.

And in terms Mars exploration it seems if want to grow stuff, one should improve one's ability to accurately predict dust storms, say a year or two into the future.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/12/2015 12:39 AM
BTW fPAR (fraction of photosynthetically active radiation) is one of the products that MODIS produces, which you can download from NASA LP DAAC.

I believe in colonization of Mars but I do not believe in Terraforming for philosophical reasons: The methane results coming out of Curiosity and Mars Express can be read as strong indications that there is life on Mars. I prefer that we do not extinguish it by transplanting the whole Earth ecosystem and overwriting the Martian ecosystem, we do not have that right. That being said I am totally in favor of exploring the planet and creating cities under domes etc. The first missions to Mars should not be Apollo one-shot where nothing of real value is left back except ALSEP, some infrastructure ought to be left to help the next visitors. If we are to try to farm in the polar region we might have one advantageous growing season but it is very likely that the facility will be destroyed by the Martian winter.  I am more in favor of the relative temperature seasonal stability of the equatorial regions. MODIS data does show high net primary productivity in the near polar regions in the peak of the season, but if you integrate over the entire year polar region NPP is pretty low. True, tropical forest NPP is also relatively low because there is massive respiration in the rainforests that cancels the massive photosynthesis. However the Martian farm is going to be more like the controlled environment of a high tech North European greenhouse and less like a natural ecosystem. The energy spent in artificial lighting is not as significant as that spent heating a greenhouse, we would prefer to situate it in a place that has the warmest average night year round. Let us not forget that frozen water will burst pipes, we must either completely drain all water in the greenhouse, heat it year round even when people are not there or bring new piping for each mission to replace what was lost when we previously abandoned it.

We can get some idea on how to colonize Mars from the (first) Age of Exploration. Food related diseases were always a problem, until Captain Cook learned how to combat scurvy (limes and sauerkraut) your typical trip to the East Indies would return with only half the ships and 1/3 the crew, the difference being food. The Portuguese made their first empire by setting up a chain of depots and station, most colonies outside the Indian Ocean where little more than a fortified storage facility. Its purpose was not to conquer the indigenous (though they eventually did that) but to provide fresh food to ships doing the spice trade. Unfortunately there is no Sao Tome or Cape to revitalize on the way to Mars, expedition one is going to be Vasco Da Gama. However we want it to be Vasco da Gama, not John Cabot going there once and the Pilgrims showing up centuries later. We want a sustained process, a Pedro Cabral setting up a factory on the second trip. In our case, because of the distance and time involved, we need to set up the factory from mission one.

I have a rough vision of what the farm experiment will look like from expedition one on. As I mentioned earlier I am more in favor of a 30 day expedition 1 rather that a 200+ day expedition, we do not know how achievable is long term farming on Mars and it is quite risky to have earth grown food in storage for 3 years. No matter how many nutritional supplements we bring it is more likely than not that some food deficiency will pop up, not only due to the need for preservation but also because we do not know the physiological response to the round trip to Mars. Doctors had no idea that we shed so many skin cells every day until the first nuclear powered submarine put people for months inside a crammed box, leading to accumulation in the bunks. It took a large number of cosmonauts and astronauts until we discovered how to combat bone loss in Earth orbit due to weightlessness, we have no idea what change Mars gravity brings to human physiology nor what is needed to combat it. There is no experiment I am aware of that had a whole greenhouse under external simulated Mars conditions. Do we know if we can keep the greenhouse up for 200 days? Do we know how plants inside will grow? Do we know if Mars sand is a good substrate and what elements will bioaccumulate in the fruits? Do we know if grounded Mars rocks will make good fertilizer and which ones? I know stories from Cyprus where unannounced changes in the fertilizer in micronutrient form from chelic iron to sulfuric iron led to sediment forming and ruining the irrigation pipes and emitters because of the hard and saline water there. There are too many unknowns to have people "living of the land" for expedition one and no real idea how shelf stable is food for years in the deep space environment. Let's reduce the risk during that mission to pave the way for the next expeditions, starting at the design stage.

The current plans for Mars call for a robotic supply ship to land where the human ship will land later carrying supplies. Among these supplies ought to be a packed greenhouse, preferably large so as to allow future growth inside there. Best cover material would be in my opinion clear PVC which does not have the fragility of glass and is not degrade easily with UV radiation as does PET. Also we need a machine to produce ammonia fertilizer, most likely using the Haber process from Martian air. Finally we need rock crushers for the other fertilizers and the substrate. The current plan is for 4 people to land (correct me if I am wrong), one will be the pilot, the other the geologist, third is the doctor and fourth the agronomist. One day one we have the one small step moments. Day two the geologists picks the most boring rocks that can be sacrificed as the agronomist starts assembling the airtight greenhouse and its associated machinery, such as the airpump or the water pump. For expedition one we can get away with bringing the fertilizer from earth, not for the rest though. In any case we need to prove that local fertilizer production is possible. It is best if we can bring some standard hydroponic substrates such as rockwool and cocopeat to compare to martian substrate material. By day 7 I see the growing facility assembled, lines set up as well as the pumps, drainage, lysimeters, automations, artificial light and cameras to record to earth, nutrient mixes etc. We pump concentrated Martian air till it get to 1 bar, then we put in the water in the nutrient mixes. We have set up the Martian substrate based on sand, silt and clay we believe is necessary for the plant, controlling the diameter of the substrate with the rock crusher. For a day or two we run the water through the production lines without plants present to test their hydraulic activities. Then we plant, most likely arabidiopsis which is what the Mars One 2018 student experiment will do despite being not usually edible because it grows fast and is well characterized. The plants will have germinated on the spaceship carrying the humans just before landing or will be set up to germinate at landing +10 days. While there is concentrated Martian air at 1 bar the agronomist works using an oxygen mask, firefighter style. After a little while the plants will germinate and grow and consume the CO2, leading to high oxygen concentration which can be sent to the habitat, one way or another. We monitor the plants until it is time to go back to Earth, making sure we have enough data and nutrient mix, we might even bring a few plants back to analyze on Earth. We remotely monitor the experiment after the astronauts have left, until the plants dies. Furthermore we monitor the facilities to see what are the energy and long term survival needs of the facilities, we still want to keep the greenhouse above 0 C even if there are no plants.

When expedition 2 arrives and we know that plants can grow and the greenhouse can survive, we set up experimental production for human consumption. On Earth even closed loop hydroponic systems require water replenishment, due to moisture leakage outside the greenhouse and phytosanitary reasons. While the artificial ecosystem will be as closed as possible we do need a water source as backup to top up. Hopefully expedition 1 experiments have identified fertilizer sources for the plants. In expedition two we have enough food from earth for the whole mission, especially when we know better its transport stability, but we will still grow food in the greenhouse so that we don't have to do so on expedition 3. It is on expedition 3 that we can go to living of the land
Title: Re: Scaling Agriculture on Mars
Post by: gbaikie on 01/12/2015 03:58 AM
BTW fPAR (fraction of photosynthetically active radiation) is one of the products that MODIS produces, --which you can download from NASA LP DAAC.

I believe in colonization of Mars but I do not believe in Terraforming for philosophical reasons: The methane results coming out of Curiosity and Mars Express can be read as strong indications that there is life on Mars. I prefer that we do not extinguish it by transplanting the whole Earth ecosystem and overwriting the Martian ecosystem, we do not have that right.

If you drill thru a mile of solid granite on Earth, you will find life down there.
And it's likely all mars life [or most of it] if on Mars is hundreds to thousands of meters under the surface.
Eg:
"The surprising discovery of deep subsurface microbial communities in the mid-1980s launched a new and rapidly expanding subdiscipline within biology, known as geomicrobiology. In geomicrobiology, the fields of geology, geophysics, hydrology, geochemistry, biochemistry, and microbiology have merged to study how life on this planet interacts with the earth's geology, how life may have originated and how life evolved over billions of years. Dark life–those organisms that thrive underground in the absence of sunlight–comprises 50 percent of the earth's biomass, is responsible for many geological phenomena, degrades our wastes and produces some of our energy. Yet many questions remain regarding dark life–questions that can only be answered by going underground."
http://www.deepscience.org/contents/dark_life.shtml
So according above 1/2 of Earth's life in underground, and Mars it might more than 99.9% of it is underground.
And we can't really stop activity on Earth due life below our feet. Life which we know very little about.



Title: Re: Scaling Agriculture on Mars
Post by: Kenm on 01/12/2015 04:29 AM
Here are a couple of papers on inflatable mars greenhouses.

http://data.spaceappschallenge.org/ICES.pdf
http://www.marshome.org/files2/Hublitz2.pdf

It looks like you need a cover or heat to stay warm through the night.
It would be nice to integrate the greenhouse into the water recycling loop with some
kind of temperature/humidity control which condenses the water transpired by the plants.
With hundreds of KwHr of energy moving through the greenhouse this would be a significant amount of water per day.




 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/12/2015 06:07 PM
I agree that capturing and condensing plant transpiration is a great way to produce clean drinking water. There are going to be Na and Cl concentration issues, not to mention bacterial load issues but I think that you are on the right path, topping up the nutrient solution for hydroponics with treated wastewater and capturing transpiration as drinking water is a great way to solve several problem. I have read of blankets being placed over high tech greenhouses on earth to reduce nightly heat loss, but this is uncommon, farmers generally try to reduce capital investments in their greenhouses due to lack of capital and required higher capital return from the crops. Obviously this is not going to be an issue on Mars.

I know that Mars soil analogues have been produced on earth. Whatever their limitation might be in terms of actually simulating Mars, it still would be a nice experiment if someone tried to see their utility as substrates here on Earth. If they are too saline see what is required to wash them of salts (and avoid reapplying them in irrigation), if the substrate is too acid how soon they can be neutralized using alkali fertilizer forms in fertigation and also see how this affects salinity, possibilities are endless. I am sure there is a big body of student, undergrads and grads, jumping to do the grunt work, is there a finding source out there giving grants? I am not in academia but I certainly remember funding was a great limiter. I think this would be a great experiment for the Mars analogue sites experiments
Title: Re: Scaling Agriculture on Mars
Post by: mitresaw on 04/08/2015 07:23 PM
Hi all.  I want to throw out an idea or two for you all to kick around.  First let me say that I am still wading through all the wonderful insight collected here at nsf forum so your literary culture is still new to me. Please indulge me.  But to get to the meat:(my simple opinions)

1.  The birth and development of the Mars agriculture frontier is the strongest factor in bleo space economy.

2.  The lunar industrial potential is dependent upon demand from the said Mars development. 

3.   We have to acknowledge that we will corrupt the prestine Martian enviornment.

As I look at it everything else is detail.

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/17/2015 08:25 PM
There has been a bit of extra conversation in the "Cooking for Mars" thread but here are a few updates since I last posted:

1. First food grown on Mars will most likely be blue green algae like spirulina and chlorella, which are faster growing than higher plants, can tolerate higher CO2 concentration (even as high as 40%) and have lower nutrient demands

2. We will contaminate the pristine environment, but this does not mean that we shouldn't try to minimize that. In countries where GMOs are allowed, you need to set up refuges. In any case it will be hugely interesting biology wise to find out which microorganisms are proven to be symbiotic for the plants. If we start growing completely sterilized seeds from earth, it is likely that we will see failure because some unknown microorganism is necessary for survival. No earth environment is truly pristine either, some necessary organisms will end up even in hyper clean seeds and allow plant growth.

3. While the greenhouses will be a wonderful source of oxygen, it is dangerous to have the air directly lead into the living space. Growing food for the colonists produces far more oxygen than what they breath, leading to excessive rich O2 atmosphere. This is the worst technical issue with MarsOne. Composting plant remains will consume O2 back to CO2, but again its timeframe is very different from that of O2 production in the greenhouse. I imagine a semi open air loop in the habitat: Mars atmospheric CO2 to biomass + O2, O2 for further use and biomass for eating and other uses.

4. New World colonization is not a great model for the interplanetary economy. While New World grown crops and preserved meat have been moving for centuries across the oceans, each planet or moon will grow its own food, except for very short distances (think Phobos/Deimos and Mars surface). Earth might feed the Moon ISS resupply style, explorers to the giant planets might top off their food in Mars or from Mars launched food, but I don't see Mars feeding the Moon or Earth
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/18/2015 03:51 AM
In a greenhouse with mature plants they can consume the entire 400 ppm of CO2 in the space of a couple of hours after sunrise. This is why we open windows very fast after sunrise. I am not suggesting venting O2, rather to store and use it
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/19/2015 06:04 AM
Their will be no greenhouses on Mars if by this you mean 'transparent buildings that grow plants in sunlight'.  It is all going to be done inside structures buried in regolith with plants lit by LEDs.

Transparent buildings are too heavy, too fragile, their is not enough Martian sunlight and it requires too large of a structure because you can't stack plants.  Indoor artificial lighting solves all these problems and such techniques are already being used on Earth for growing salad crops in urban areas.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/19/2015 07:03 AM
Their will be no greenhouses on Mars if by this you mean 'transparent buildings that grow plants in sunlight'.  It is all going to be done inside structures buried in regolith with plants lit by LEDs.

Transparent buildings are too heavy, too fragile, their is not enough Martian sunlight and it requires too large of a structure because you can't stack plants.  Indoor artificial lighting solves all these problems and such techniques are already being used on Earth for growing salad crops in urban areas.

I suggest you read this pdf:

http://data.spaceappschallenge.org/ICES.pdf

It was linked in this post by Kenm

http://forum.nasaspaceflight.com/index.php?topic=35877.msg1314576#msg1314576

It is very interesting.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/20/2015 01:17 AM
I in turn would send you here:

http://spirit.as.utexas.edu/~fiso/telecon/Do_2-11-15/

The students are obviously engineering students using preexisting models but they stumble into something well known by agronomists: mature plants in sufficient quantity to produce enough food for the crew consume O2 in quantities far in excess of what the crew breathes. On earth this is not an issue, we have the buffer of the atmosphere plus we are adding new carbon constantly through fossil fuel burning. On Mars though having plants and people on the same air is dangerous.

Equatorial Mars under non dust storm condition has similar solar radiation level as the Netherlands during a cloudy day. Considering that cloudy day is the typical condition in that country and that under those condition they have some of the highest yields in the world, I say that yes, we can use martian sunlight. True, I do not know how to make the greenhouse airtight enough for Mars, perhaps and inflatable structure is best, perhaps we just need to thermally glue the panels well. Considering that it will be a great prototype for future Mars habitat domes, I would say let's go with a surface greenhouse.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/20/2015 03:11 AM

I suggest you read this pdf:

http://data.spaceappschallenge.org/ICES.pdf

It was linked in this post by Kenm

http://forum.nasaspaceflight.com/index.php?topic=35877.msg1314576#msg1314576

It is very interesting.

Garbage in, Garbage out, (and then in and out and in and out).  Literally these papers are just recycling numbers from earlier papers which are themselves siting even earlier papers which are based on a NASA growing chamber built in 1988, the conclusions are very nearly 20 YEARS out of data with regard to artificial lighting efficacy, LED's did not even EXIST yet and all the conclusions are based on obsolete Sodium Vapor lamps.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/20/2015 04:26 AM
Wheat, corn, and rice will probably require greenhouses with natural light.  Arched Quonset type greenhouses will not be hard to build and can be very long for growing food without artificial light.  They wouldn't be hard to build either.  They can be built and extended in sections so sealing can be done along the way in case of a crack or leak.  Also, being able to see outside and to have the feeling of being outside even if in a greenhouse would be good for humans. 

Surely Mars also has soil with sand that can be used to either make glass, or plexiglass can be brought from earth in sheets to be snapped into prefab framing.  I have seen some commercial greenhouse roofs made completely of inflatable plastic.  Puts an air barrier in to help insulate from cold winters to cut down on heating. 
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/20/2015 04:46 AM
Noooooo, primary starch crops need the MOST intense light to reach photosynthetic threshold and can effectively utilize very near full Earth sunlight, these are the crops that would most drive us to utilize artificial light.  Mars natural light would be adequate for more 'salad' type crops things like spinach and lettuce which have lower thresholds and lower maximum light absorption.

AegeanBlue:  The 'productivity' of a Tulip farm in the Netherlands is measured in $$$, not calories.  I can assure you that their caloric productivity is pathetic compared to Midwest corn farms, Brazilian sugar cane and Southeast Asian rice paddies, all places with a lot more light.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/20/2015 05:26 AM
Primary souce of starch and oil and oxygen will most likely be algae. No issue with pressurized volume. They will be grown in pipes. Very cheap and lightweight, very efficient to cover large areas.

http://www.ncbi.nlm.nih.gov/pubmed/21404251

BTW wheat is the only crop identified in that pdf that will perform less than max. efficient under martian light conditions. Other conventional starch producing plants do quite well. Crops like vegetables grow perfectly well even under light density during severe dust storm conditions.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/20/2015 06:21 AM
Corn and sugar cane are C3  C4 plants which utilize more efficient photosynthesis cycle, they have that advantage in any lighting.

Noooooo, primary starch crops need the MOST intense light to reach photosynthetic threshold and can effectively utilize very near full Earth sunlight

A citation with PI curve to prove this please. All curves I've seen plateau well before full sunlight.

Quote
AegeanBlue:  The 'productivity' of a Tulip farm in the Netherlands is measured in $$$, not calories.  I can assure you that their caloric productivity is pathetic compared to Midwest corn farms, Brazilian sugar cane and Southeast Asian rice paddies, all places with a lot more light.

Yes, a tulip farm surely has poorer calorific production than staple crop farms, irrelevant of location. However high calory crops grow there quite well. Quick googling didn't produce crop yields from there but not so far from it and even slightly further north in Lincolnshire UK holds the new UK wheat yield record of 14.5t/ha (http://www.fwi.co.uk/arable/lincolnshire-grower-sets-new-uk-wheat-yield-record.htm), which is pretty darn good open field result at 53 N latitude. About one tonne less than current world record from New Zealand.

edit: mixed up C3 and C4, thanks AegeanBlue!
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/20/2015 04:31 PM
First of all corn is a C4 plant, not a C3 plant. For that matter it is the only major C4 plant, the rest of C4 plants are horticultural at best. C3 plants saturate at North European sunlight levels and do not significantly benefit from the higher intensity of Southern Europe, though they benefit from the longer sunlight hours. In any case the seed companies produce varieties optimized both for low and high light condition far all plants, future agronomists will pick a variety optimized for the martian solar conditions.

In the Netherlands greenhouse tomatoes have three times the productivity of greenhouse tomatoes at Ierapetra, which is on the south coast of Crete and one of Greece's major greenhouse zones (go there with Google Maps and admire the lack of actual fields, almost every piece of flat ground is covered by greenhouses). Why? At Ierapetra a greenhouse without cooling reaches a noontime temperature of 40 C already from March, which is why windows get opened from 10 am the latest except for the rare cases of frost. From June on without active cooling panels (which work only due to the dryness of the Mediterranean summer, A/C is uneconomical for greenhouses) greenhouses are too hot for any plant at Ierapetra or, for that matter, most of Greece. The lower sunlight intensity and miserable weather lead to higher productivity in the Netherlands due to longer growing season. That being said the tomatoes from Crete are tastier than tomatoes from Northern Europe and do have a higher Brix content, because due to higher photosynthesis there is more carbohydrate accumulation in the fruit.

BTW with the exception of genomics and few other cases, a 20 year old paper is not considered obsolete in agronomy, far from it. Over the last 20 years there has been an improvement in greenhouse automations, but otherwise greenhouses have been using the same methods, on the same facilities even and often the same biological material. Yield has gone up, water consumption down, new substrates have been tried, but otherwise farming has been going the same way.

If you are looking for references on crop yields, in the US look at your local agricultural extension agency websites. That is where I found the data I needed for my dissertation, which I combined with RS data to create geospatial yield models. In Europe your local agricultural university and ministry of agriculture can help you get the data. Acta Horticulturae is a relevant scientific publication for all this horticultural, including high end greenhouses
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/20/2015 05:24 PM
To have some idea of what I am talking about when discussing spirulina, here are a couple of videos from Europe's only spirulina production facility, near Nigrita, of Serres. Maybe it is not the best way to go, since they used warm CO2 enriched water coming out of the local geothermal field. However the farmers claim not to need to fertilize the plants with anything, the just use the water:

https://www.youtube.com/watch?v=o38wZXJWdu4

https://www.youtube.com/watch?v=rhs7dDqNT0A

There is also a video from Greek state TV from 2010 where the farmers discuss their facility and why eating spirulina is good for you, but the whole thing is in Greek and not subtitled
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/20/2015 06:39 PM
Very intersting, I did not know that Spirulina is produced in Europe. I thought it is only in Asia, Japan. Spirulina or generally algae production on Mars would look different. No large pressurized greenhouse needed. The water would circulate in transparent pipes or hoses. At that small diameter material required for pressurization is very little, optimized for transparency. A larger greenhouse would span the whole area, but just for the greenhouse effect, to keep it warm. It would be pressurized only enough to keep it in shape, so again a very thin material can be used, optimized for transparency, not for strength. The material would need a coating to retain infrared.
Title: Re: Scaling Agriculture on Mars
Post by: TripD on 04/20/2015 06:49 PM
Wow!  This thread is most educational...... thanks to all.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/20/2015 08:34 PM
First off, I wouldn't want to live on Mars if I had to be cooped up underground the entire time.  Thus greenhouses.  Second, winter wheat is grown in southern Canada and in Russia where there is less sunlight than 1,000 miles further south.  Third, I know of someone who grew okra, a southern plant, that will not even germinate until May in most places, in a greenhouse in Alaska.  It took a little longer to grow, but it grew, and they had okra.  Fourth, even if there is not enough intense sunlight on Mars, it can be supplemented with some UV lighting thus saving a lot on completely underground electricity.  Fifth, small diameter arched greenhouses can be strong.  Smaller panes could be used so as if one is broken from an errant meteorite, it could be patched quickly and replaced quickly by one person.  Also a Kevlar type cover could be pulled over it at night for further protection.  Also, with Mars having a 24+ hour day, plants, and animals for that matter, wouldn't have a hard time adjusting to the day-night cycle. 

I just think it would be nice to come from out of your underground, or soil covered home and walk into a greenhouse and look out at the Martian desert landscape, and the green plants, and feel refreshed.  Another thing that might be built using the basalt building material is a swimming pool.  If people are going to be underground, they need spaciousness, high ceilings, and sometimes a view outside. 

Farming communities might have to be near the equator, while some type of surface transportation system might have to rail, or truck ice from the poles.  The entire planet would have to be surveyed, possibly on land, to find whatever natural minerals are available.  Metals, and basalt materials, are going to be needed to manufacture structure material for living, and growing food, and even flowers.  Small fruit trees and bushes would need to be grown that doesn't require a lot of space such as peach, pear, apple, blueberries, blackberries, strawberries, grapes, figs, etc.  I have three grape vines that cover my gazebo and my wife makes grape jelly and a few quarts of wine each year.  Small spaces can produce a lot. 

Eventually there would have to be small animal production such as chickens, ducks, quail, rabbits, maybe even pot bellied pigs, that do not require a lot of space.  There will be a need eventually for real food, not synthetic food.  A 4' deep x 4' wide x 8' long tank of tilapia can grow enough fish for a family of 4 for one meal a week in a year.  Waste can be used for plant fertilizer and aquaculture for hydrophonics.   

One great advantage of this research and development is the agricultural practices used on Mars can be applied to earth and much greater productivity can be accomplished on much smaller space to ward off famine and hunger in the world. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/20/2015 08:40 PM
I am more in favor of a general purpose greenhouse, large enough to stand, where side by side with benches of spirulina lines and water mixers there are benches with lines of more palatable crops. We could be feeding spirulina with the water coming out of the hydroponics, because even in closed loop systems you need to get rid of the water after a few loops. There is also the need of the thermal buffer provided by the larger air volume. Now I remember that while PET needs IR coating, glass does not, it naturally reflects back almost all IR energy. There is little agreement yet on what the Mars diet will look like, the MIT students testing the viability of MarsOne did use a few food models based on papers to properly dimension the food production facility, though from what I saw (and I did not read the paper, just the pdf) there were pretty conventional major crop choices in the food mix. The earth analogue studies mostly depend on canned food rather than try to grow everything at the base.

We are at a typical point for most Mission to Mars studies, in need of optimization while ignoring what is desired or achievable, just guessing. On Earth heavy menial labor requires ~5.000 cal/day. Do we need that for Mars' lower gravity? Can we provide a plant based diet for that? Yes, but then this requires all sort of engineering choices, which eventually require the use of human resources, which in turn affects how many calories are needed to be consumed and eventually grown. So far no food has been grown and consumed in space, even in the recent Veggie experiment on the ISS they took down the lettuce to Earth to see if it is safe to eat, rather than feed it to the astronauts.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/20/2015 08:48 PM
First of all corn is a C4 plant, not a C3 plant. For that matter it is the only major C4 plant, the rest of C4 plants are horticultural at best. C3 plants saturate at North European sunlight levels and do not significantly benefit from the higher intensity of Southern Europe, though they benefit from the longer sunlight hours.

Sugar cane is definitely another higher efficiency C4 widely used crop plant. It tops the higher plants photosynthesis efficiency charts. Other C4 crop plants usually listed are sorghum and millet.

Strong contender for dimmer lighting, cooler environment starch production could be good old potato.

To have some idea of what I am talking about when discussing spirulina, here are a couple of videos from Europe's only spirulina production facility, near Nigrita, of Serres. Maybe it is not the best way to go, since they used warm CO2 enriched water coming out of the local geothermal field. However the farmers claim not to need to fertilize the plants with anything, the just use the water:

Does the water contain enough plant usable nitrogen ions or does Spirulina fix it directly from atmosphere?
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/20/2015 09:30 PM
Tilapia are actually vegetarian fish.  The young eat algae, so any excess algae can be fed to tilapia.  As they grow bigger, they eat larger water plants. 

Nitrogen might be the rare element needed on Mars.  The plants will need the nitrogen.  Animal waste is one method as well as fish waste for fertilizer.  Hopefully it will not have to be brought from earth.  Looking it up Mars has 1.9% nitrogen in the atmosphere as well as 1.9% argon, so both could be extracted.  Nitrogen for fertilizer, and argon for SEP propellant, if SEP tugs bring things to Mars, they could also refuel for the trip back with a reusable launcher/lander to orbit using metholox fuel also made from the atmosphere and water found on Mars. 

If a lot of colonists go to Mars as Elon Musk desires, agriculture, aquaculture, hydrophonics, etc will have to be priority. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/20/2015 09:31 PM
Does the water contain enough plant usable nitrogen ions or does Spirulina fix it directly from atmosphere?

Spirulina need nitrogen in plant consumable form like nitrates. They don't get it from atmospheric nitrogen gas. Producing nitrates will be a necessary part of plant growing. Though much will be recycled from urin and feces, duly processed.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/20/2015 10:18 PM
Corn and sugar cane are C3 plants which utilize more efficient photosynthesis cycle, they have that advantage in any lighting.

Noooooo, primary starch crops need the MOST intense light to reach photosynthetic threshold and can effectively utilize very near full Earth sunlight

A citation with PI curve to prove this please. All curves I've seen plateau well before full sunlight.

Quote
AegeanBlue:  The 'productivity' of a Tulip farm in the Netherlands is measured in $$$, not calories.  I can assure you that their caloric productivity is pathetic compared to Midwest corn farms, Brazilian sugar cane and Southeast Asian rice paddies, all places with a lot more light.

Yes, a tulip farm surely has poorer calorific production than staple crop farms, irrelevant of location. However high calory crops grow there quite well. Quick googling didn't produce crop yields from there but not so far from it and even slightly further north in Lincolnshire UK holds the new UK wheat yield record of 14.5t/ha (http://www.fwi.co.uk/arable/lincolnshire-grower-sets-new-uk-wheat-yield-record.htm), which is pretty darn good open field result at 53 N latitude. About one tonne less than current world record from New Zealand.

C3 vs C4 mix up has already been addressed most grasses are C4 btw, C4 plants have more efficient Carbon fixation, not light absorption, they have an advantage in high light and temperate and a DISADVANTAGE in low light conditions and low temperatures, this is why C4 plants dominate the tropics and C3 plants dominate temperate regions.  It is actually the C3 plants which generally contain more chlorophyll (like spinach) and collect light more efficiency because light is often the limiting factor in their growth.

But any logical greenhouse will have elevated CO2 levels of around 1% (still breathable for humans) which will largely neutralize the C4 advantage by reducing photo-respiration in C3 plants.

R7 & spacenut: For crying out loud crop yields in a Temperate (and especially the Arctic) zones are the result of this thing called SUMMER, in which the Earths tilt causes HIGHER daily light flux then in a tropical region because of improved solar angle and increased day length the total daily light flux shifts by nearly an order of magnitude between summer and winter as can be seen here http://www.leidi.ee/wb/media/INSOLATION%20LEVELS%20EU.pdf.  The Martian equator is going to have light levels comparable to a Temperate zone winter EVERY DAY, best case (a dust storm will cut that in half again).

According to http://ccar.colorado.edu/asen5050/projects/projects_2001/benoit/solar_irradiance_on_mars.htm Martian sunlight after accounting for extinction is only delivering around 50 W/m^2 of Photosynthetically active radiation (PAR) average per day, that could be replicated with just a handful of LED diodes.  But we would apply more then that we get faster growth and a denser food output per of growing area.

guckyfan:  I agree that 'vat' grown nutrients are more likely to be the core caloric staple rather then traditional starch crops, but again this will not be powered by sunlight.  Again it will be artificial light because we can pack the lighting and algae tubes together at high density into an appliance side device and avoid having a whole separate structure to house it.  Their are also systems based on Methane eating bacteria which can produce large quantities of protein, see http://www.unibio.dk/technology/
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/20/2015 11:24 PM
Food in a temperate zone can be grown every day in a greenhouse in winter.  I have a greenhouse.  So if Mar's equator is like the temperate winter.  No problem with using natural light.  Also nice for human eyes to look out on the horizon from a greenhouse window.  Plants need UV light, not just LED light.  My family has grown African violets inside, but they had to have UV light.  Sunlight is free, so why not use it.   
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 04/20/2015 11:58 PM
I bet there is a simple way to exploit sun light moderately directly, but here is a link on LED grow lights.
http://en.wikipedia.org/wiki/Grow_light#LED

(took a while to find a link that wasn't about growing weed in your basement ;) )
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/21/2015 12:13 AM
From http://www.seps.sk/zp/fond/dieret/solar.htm

Quote
The solar energy which is available during the day varies and depends strongly on the local sky conditions. At noon in clear sky conditions, the global solar irradiation can in e.g. Central Europe reach 1000 W/m2 on a horizontal surface (under very favourable conditions, even higher levels can occur) whilst in very cloudy weather, it may fall to less than 100 W/m2 even at midday.

As said a few pages ago, in the fabled greenhouses of Northern Europe, where land is expensive, solar radiation is low and capital is cheap, they supplement the low solar radiation by having supplementary artificial lighting. Sure, you can make the conditions completely artificial, though on Earth this is usually associated with illegal crops such as cannabis. In any case, the sun will rise on Mars every day, you do not know about the reliability of your lighting and electronics. You will need some sort of day length control anyway for photoperiodism, both to shorten and to lengthen day length for flowering. A super dense completely artificial plant habitat can be an oxygen bomb, a fire hazard and a hyperbaric chamber; I don't we would want conditions where a spark can cause a disaster. To be honest though we do not know what will be the PAR on a plant inside a greenhouse on Mars until we actually build one. Also we do not know how much effort will be required to wipe away the dust from the outside of the greenhouse, how much will enter and what its effects will be. In any case though, I don't think we will require Fe fertilization on Mars, dust will provide plenty of material.

Agriculture on Mars is impossible without the Haber-Bosch process or some other process to produce N fertilizer. On Earth plants gets their Nitrogen fixed by bacteria and it is fixed at very low concentrations. Even if we do bring them on Mars, they will not produce N at sufficient quantities for intensive agriculture. Also, historically hydroponics was commercialized because too many pests and enemies colonized the greenhouse soil to the point that it was no longer possible to grow anything on the native soil. Granted, it is far harder to bring pests across interplanetary space but it is an eventuality.

C4 plants fix CO2 more efficiently that C3 plants which allows them to take advantage of the higher solar irradiation of subtropical and tropical regions. If my textbook was not on the other side of the Atlantic I would be pasting here the graph on how C3 plants have higher photosynthesis on low light intensity than C4 plants. High CO2 concentration acts as fertilizer for the plants, up to the point of toxicity, and for that matter there is carbon fertilization used in Northern Europe. For higher plants there is no benefit to CO2 concentration above 1,5%, spirulina though can survive up to 40%. I see martian air being pumped in at sunrise, stopping the pumping a couple of hours until the workers get in, workers getting in when the air is safe and then leaving, and a return to pumping Martian air. O2 needs to be collected and removed, we can pull out argon too but let's let N2 concentration rise until the N2/O2 balance gets to earth ratios. We will need selective absorption and removal of what the plants produce in any case. Be aware too that a greenhouse, and even more so an artificial bio-reactor food type construct, is a highly corrosive environment on Earth, in 20 years you will need to replace the Aluminum beams, wood beams rarely last more than 10 years. PET cover material survives 1-10 years depending on quality, glass can go for centuries and acrylic can also last decades, we just don't know how long because it hasn't been around that long. Obviously on Mars conditions we have no idea.

Photosynthetically Active Radiation (PAR) consists of both the UV AND IR part of the spectrum, along with a large part of the visible. Green is quite useless, hence reflected. Most lamps sold are optimized for human viewing, if we go the LED way we should best optimize for PAR. Correct me if I am wrong, but as far as I remember LED has a conversion efficiency in the order of 50% which can optimized depending on the wavelength.

In the end the final decision is up to the colonizers: Do we want underground highly intensive, highly corrosive complex artificial constructs, not used on earth except experimentally or do we want to use hydroponic greenhouses, that have been used on earth for decades and are well know and characterized, albeit in a novel and unknown environment?
Title: Re: Scaling Agriculture on Mars
Post by: nadreck on 04/21/2015 12:16 AM
I bet there is a simple way to exploit sun light moderately directly, but here is a link on LED grow lights.
http://en.wikipedia.org/wiki/Grow_light#LED

(took a while to find a link that wasn't about growing weed in your basement ;) )

There could easily be underground, pressurized growing facilities that used sunlight that was reflected and concentrated to provide optimized levels for plants.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/21/2015 12:20 AM
African Violets are not food, their is a staggering difference in the light levels needed for crops and ornamental plants, many of which are understory plants that are adapted to low light levels, you can't build up any kind of starchy biomass with these plants.

At best you could grow some salad type crops using Martian light levels and if that's all your doing then the energy cost of doing it full indoors is so small you would not bother with all the engineering challenges of creating thin, transparent, rip resistant, meteorite resistant, UV resilient, insulated, huge ground footprint greenhouses.  Sunlight is free but highly engineered structures are NOT.

You would not bother with all this mess and instead make a simple room inside the habitat with grow-lights like the Antarctic research station uses to produce some salads that while insignificant nutritionally have proved highly valuable for moral.

And their is absolutely NO reason you need to 'look out on the horizon from a greenhouse window', it is literally the most ridiculous romanticism-of-mars argument I have ever heard.  First off the Martian landscape is about as ugly and boring as the Antarctic, you don't see most researchers over wintering clamoring to get to the windows, second their can be windows in OTHER places for scoping out the surface such as an observation tower (useful for all kind of safety and logistical reasons) as well as simple portholes.

It is true that people DO like to spend time in and around the growing plants in the Antarctic and they aren't the least bothered that this is in an indoor room with artificial lighting.  But, having a thin bubble greenhouse means the greenhouse if a high cosmic radiation environment and people would be advized to limit their time in it, a regolith covered artificially lit growing area can be occupied indefinitely making it infinitely better from a moral boosting perspective.

You clearly don't know anything about modern LED's if you think their is just one kind of LED light or that they are incapable of making UV.  Modern LED grow lights contain a mixture of different diodes tuned to different frequencies of light that are most desirable for plants, virtually all the light can be PAR (photosynthetically Active Radiation) and the mixture can be adjusted to promote certain activities of the plant such as flowing or fruiting.  UV is not PAR but some plants need small quantities of it to stimulate parts of their growth cycle, LED grow-light fixtures are moving to add this to the mix along with certain yellow frequencies that also have stimulative effects.  Fixtures with 5 or 5 different frequencies are likely to become the norm.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/21/2015 02:00 AM
Major crops can also grow in low lighting, potatoes come to mind readily. Farmers grow ornamentals in greenhouses for income reasons, not due to lack of radiation. Hydroponics can grow any crop, it is simply not economical to grow major crops in greenhouses when farmers with farms the size of entire countries produce them on the field. It is however highly achievable technically and has repeatedly happened experimentally. A greenhouse is a far safer solution than a closed room with artificial lighting, we already have the materials (clear acrylic) and the know how and there have been experiments already to test the radiation tolerance of plants to cosmic radiation by the Soviets/Russians. As for aesthetics, I leave it to others.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/21/2015 04:08 AM
A greenhouse is a far safer solution than a closed room with artificial lighting

This is ridiculous assertion, please explain how a thin inflated balloon naked to the Martian elements is safer then a room inside the normal rigid walled habitat covered in meters of radiation blocking regolith.

Why are you even mentioning Hydroponics, no one has even mentioned differences in growing mediums, this is literally the only aspect of the growing system that dose not have any bearing on natural vs artificial light debate.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/21/2015 05:37 AM
guckyfan:  I agree that 'vat' grown nutrients are more likely to be the core caloric staple rather then traditional starch crops, but again this will not be powered by sunlight.  Again it will be artificial light because we can pack the lighting and algae tubes together at high density into an appliance side device and avoid having a whole separate structure to house it. 

We can argue, wether natural or artificial light will be used for conventional crops. It will be an engineering problem to solve for best overall efficiency. The trades are complex and different solutions may be possible or maybe one would clearly dominate.

For example a compact simple efficient fusion power source should make artificial lighting very competetive. A light high tensile strength transparent material may make greenhouses efficient.

One point in favor of natural light greenhouses. Higly efficient LED lighting may be good for plants but it looks horrible. For people to have something they want to look at a conventional greenhouse with natural lighting that provides an additional view over the landscape outside will be needed even if much is produced under artificial lighting. Antarctic research stations are not a good counter argument. People can go out of their habitats, given good protective clothing. Let's see if spacesuits can get so wearable that people, even children can do that on Mars.

But the situation with algae is different. Algae growing has the advantage, that it does not need complex expensive equipment. The requirements of material properties is low so that they will be the first that can be produced on Mars. So it is natural lighting for algae. That will make them so cheap to produce that they can enable raising animals for food.

Their are also systems based on Methane eating bacteria which can produce large quantities of protein, see http://www.unibio.dk/technology/

Yes, an important point. Methane plus nitrates will enable efficient protein production. I believe, I was the first on this forum to point that out.  :) The product is already approved for animal feed in the EU. They can be made safe for humans too. However as was already pointed out upthread, for a colony to be attractive for people to have a family and raise children, quality and attractive food are important. It would be a major, but I hope doable challenge, to make attractive food from algae and bacteria protein.

A research station with scientists might be different. Scientists will put up with anything, that keeps them fed for the duration of a science mission for the chance to do research on Mars. Fresh vegetables as a bonus will be appreciated  for sure though.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/21/2015 06:13 AM
For one thing Antarctica has very small days during winter, artificial lighting is necessary during  the small days. I have been to Russian in June, have seen the 20 hour days with no real night beyond twilight, I can imagine why artificial lighting is necessary in the Antarctic winter.

I say that a greenhouse with a thin film is safer than a wall because no matter what you will have light during the day. A power out can bring down photosynthesis pretty hard if no light comes in. True, my thinking is more Apollo 13, that of a crippling accident but I am against a single point of failure, an electrical short should not mean long term death. Now, greenhouse cover material has proven pretty durable if you are willing to pay the price: acrylic can survive hailstorms, let alone the dust storms of Mars. In any case greenhouse quality acrylic panels have very high transmissivity, better than glass, are a couple of cm thick, have low structural needs (unlike glass) but are expensive. I am not talking about the paper thin PET film, which after all is only supposed to last one season and has serious UV stability problems.

I have repeatedly mentioned hydroponics in this thread not to highlight the difference in the mediums but for the high yield and quality of farm products they produce and its adaptability to diverse conditions. On several Mars colonization literature such as Kim Stanley Robinson' Mars Trilogy or websites, such as the excellent Mars Pioneer which this website promotes, there is the misconception that we can easily transfer nitrogen fixing bacteria to Mars soil and grow on said soil. Also, the high end greenhouse of Northern Europe with all the automations that allow high yield under dismal conditions, grow their crops hydroponically, not on their soil.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/22/2015 06:52 AM

For example a compact simple efficient fusion power source should make artificial lighting very competetive. A light high tensile strength transparent material may make greenhouses efficient.

FUSION!??  You think you think we need fusion to make artificial lighting viable???  Boy really reasonable bar your setting their, I'd been thinking we would need to harness zero-point quantum vacuum energy or controlled singularities.

Seriously, were looking at a few Kw per person, what ever size transparent greenhouse you had been planning multiply it a few times and throw down thin-film solar panels and you have the energy covered.

One point in favor of natural light greenhouses. Higly efficient LED lighting may be good for plants but it looks horrible. For people to have something they want to look at a conventional greenhouse with natural lighting that provides an additional view over the landscape outside will be needed even if much is produced under artificial lighting.

Ascetics makes for a very weak engineering argument, especially when wrong.  Most LED grow light systems have a simple 'white light' switches that has them put out a mix of light comparable to sunlight and which is is 'true color' for the human eye, it is used to help people when examining the plants for disease/discoloration etc.


Antarctic research stations are not a good counter argument. People can go out of their habitats, given good protective clothing. Let's see if spacesuits can get so wearable that people, even children can do that on Mars.

Antarctic researchers leave the insides of their stations during winter less then Astronauts are likely to leave their habitats on Mars.  And 'good protective clothing' is a description of a Parka as much as it is a description of a space-suit, I see no substantive difference in the amount of 'cabin-fever' that people are going to experience and how this would make an indoor growing area unacceptable.



But the situation with algae is different. Algae growing has the advantage, that it does not need complex expensive equipment. The requirements of material properties is low so that they will be the first that can be produced on Mars. So it is natural lighting for algae. That will make them so cheap to produce that they can enable raising animals for food.

I see no reason why the near term nature and low complexity of algae is an argument for natural light.  If anything this is an argument for artificial light because we HAVE artificial lights now and combining them with clear tubes in some kind of algae-vat-machine would be trivial and it could just fit in a standard rack on a spacecraft (we could even validate the thing on ISS), but Mars capable greenhouses do NOT exist yet and the development of the system your proposing is considerably lengthier.


Yes, an important point. Methane plus nitrates will enable efficient protein production. I believe, I was the first on this forum to point that out.  :) The product is already approved for animal feed in the EU. They can be made safe for humans too. However as was already pointed out upthread, for a colony to be attractive for people to have a family and raise children, quality and attractive food are important. It would be a major, but I hope doable challenge, to make attractive food from algae and bacteria protein.

A research station with scientists might be different. Scientists will put up with anything, that keeps them fed for the duration of a science mission for the chance to do research on Mars. Fresh vegetables as a bonus will be appreciated  for sure though.

The simplest means will be to blend the unpalatable powders of protein and carbohydrates with the fresh grown produce such that the flavor and texture of the fresh produce dominates the palette, while the powders provide the bulk calories. 

For example protein powder and fresh Strawberries could be made into a decent smoothie/milkshake.  This strategy allows us to lift the high calorie burden from our farming operation, which would have driven us to a rather bland set of starch crops (peanuts, potatoes, wheat) and instead focus on salad vegetables, fruits, aromatic seasonings and spices, all of which are caloricly poor.  Thus the use of 'vats' may actually allow food to be more palatable then it would be if it was all grown.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/22/2015 07:20 AM
For one thing Antarctica has very small days during winter, artificial lighting is necessary during  the small days. I have been to Russian in June, have seen the 20 hour days with no real night beyond twilight, I can imagine why artificial lighting is necessary in the Antarctic winter.

I say that a greenhouse with a thin film is safer than a wall because no matter what you will have light during the day. A power out can bring down photosynthesis pretty hard if no light comes in. True, my thinking is more Apollo 13, that of a crippling accident but I am against a single point of failure, an electrical short should not mean long term death. Now, greenhouse cover material has proven pretty durable if you are willing to pay the price: acrylic can survive hailstorms, let alone the dust storms of Mars. In any case greenhouse quality acrylic panels have very high transmissivity, better than glass, are a couple of cm thick, have low structural needs (unlike glass) but are expensive. I am not talking about the paper thin PET film, which after all is only supposed to last one season and has serious UV stability problems.

I have repeatedly mentioned hydroponics in this thread not to highlight the difference in the mediums but for the high yield and quality of farm products they produce and its adaptability to diverse conditions. On several Mars colonization literature such as Kim Stanley Robinson' Mars Trilogy or websites, such as the excellent Mars Pioneer which this website promotes, there is the misconception that we can easily transfer nitrogen fixing bacteria to Mars soil and grow on said soil. Also, the high end greenhouse of Northern Europe with all the automations that allow high yield under dismal conditions, grow their crops hydroponically, not on their soil.

I can assure you that lose of electricity on Mars means death for a myriad of reasons OTHER then crop failure, and indeed they all happen LONG before starvation.

A temporary outage of power and artificial lighting is less likely then the guaranteed dust storms which are certainly to occur and drop the light levels of a naturally lit greenhouse to exceedingly low levels such that plants will not be growing at all and may even be in danger of dieing.

Acrylic panels are a viable material for a greenhouse, the largest challenge would be construction as this dose not sound like an inflatable system anymore.  UV is an issue not only for the greenhouse materials possible degradation, it must be actively blocked to protect the plants inside.

I agree that Hydroponics are likely to be employed and Mars regolith is unfit as growing medium, it's full of toxic compounds and is devoid of organic matter, it has none of the microbial and fungal activity that makes real soil desirable, at best it could supply some mineral cations, but a few pounds of fertilizer would do the job better.

Finally, one of the 'automation' used in Norther European greenhouse is artificial supplementary lighting for winter and cloudy days.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/22/2015 08:34 AM
Read that linked PDF. They come to a completely different conclusion regarding dust storms. While they  impede the yield of some high caloric plants they leave absolutely enough light for raising vegetables and all kinds of green plants.

Yes, loss of electricity would be fatal. A good mix of sources is desirable. But it is certain that solar would never be lost because of massive parallel reduncancy. Again duststorms reduce the yield but it would always be enough to keep the habitats running. More energy intensive industrial activities like fuel production may need to be scaled down or worst case stopped.

Regarding soil and no organics. Organics may be desirable in soil but they are not essential as long as mineralic fertilizer is supplied, just like in hydroponics. Organics will build up fast enough from roots left in the soil from early harvests. Eliminating the toxic components is not that hard to do.

In fact such organics may cause a problem in hydroponic substrates. On earth massive amounts of water are needed to clean them. Cleaning may be more difficult on Mars. At least good new solutions need to be developed. Some plants can grow and be held in place without a substrate but not all. I am not yet decided which approach ist the longterm more feasible. Probably a mix of both.

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/22/2015 08:02 PM
The experimental greenhouse that I worked for my thesis in Portugal, oh so long ago, had two substrates: rockwool and cocopeat. Organic material is a possibility for hydroponics, though rarely the most desired. Hydroponics most often works with inorganic substrates, for 3 to 5 growth cycles, until the substrate has too much root material to allow another plant to grow. Of course this creates a waste stream eventually. Standard publication in hydroponics is "Authors tried new material as substrate and substrate worked compared to standard rockwool/cocopeat/whatever is used in the region". I am more inclined to believe that sterilized Mars soil will also prove a sufficient substrate as I said a few pages ago, we simply need a few experiments on earth, with soil analogues, very likely after we get an actual sample back so we can have some idea of what the micronutrient composition is. By adding a few buffering ions and controlling pH, we can facilitate or discourage the plant availability of any element. In these test we can also use Mars lamps, simulate good conditions and dust storm and settle whether the use of natural lights is beneficial from an agronomic POV. I am of the opinion that it is beneficial based on my earth experience. The environment of a high tech hydroponic greenhouse is both complicated and corrosive, ruggedization will only go so far, a badly timed short on the lighting system with no space part available or unprintable by 3d printing should not lead to a loss of crop and a few weeks for reestablishment of the next crop.

I was never a friend of inflatable greenhouses. Acrylic panel greenhouses on Mars would very likely not even require a frame due to the lower gravity. We can just glue them with resins. I still see though a frame for the plants to leave their weight, places to frame automations and machinery (think thermal blankets for the night) and an entry joint for the separate airlock of the greenhouse. Unless you are growing lettuce or some other plant that does not take volume, you will need a frame to hang the plant, and I never understood where these would fit in an inflatable greenhouse.

What I definitely remember from Horticulture class was a diagram of calories and nutrient (protein, carbohydrates etc) produced by a field crop of wheat and a field crop of tomatoes. Tomatoes produced more nutrients per area than major crops. Do not underestimate the nutritional value of vegetables, if they grow sufficiently in low light situations, so much the better.

Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/22/2015 09:00 PM
My son is majoring in aquaculture.  Aquaphonics is the latest development.  Tilipia in a tank eat algae and water plants when they get larger.  Their organic waste is pumped out the bottom and fed to hydrophonic plants.  This saves on fertilizer.  A small greenhouse coupled with a 4' x 6' x 8' tank of tilapia can provide fish once a week and all the vegetables a family of four can eat in a year.  It doesn't take much, but has to operate year round.  Wheat, rice, corn, and other grains will take more space, but usually only an acre per family for the grains.  Rice will need more water.

More fish could be grown for more plants, and the fish processed for substitute seafood products. 

In China they are growing chickens over tanks of catfish.  Chicken manure is only half digested plant material.  Catfish will eat this.  The waste from the catfish is used for fertilizer. 

Algae can be processed into pellets to feed chickens or fish.  Instead of humans eating algae products, we could eat actual eggs, chicken, and fish.  Whereas soy protein could be processed into synthetic hamburger.  However some people like me are allergic to soy products and peanuts. 

Food supplies from earth can continue to be brought during the 6 month intervals, but fewer and fewer as aquaculture etc takes hold.  Grain products will be what is probably brought, as well as maybe frozen steaks, hams, etc.  Since space is cold and outside accessible freezer panel could be installed on an MCT for bringing frozen meats from earth.  Keeping food cold or frozen on Mars shouldn't be a problem if a freezer unit is placed on or near the surface accessible from inside a sheltered unit. 
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/23/2015 12:27 AM
Read that linked PDF. They come to a completely different conclusion regarding dust storms. While they  impede the yield of some high caloric plants they leave absolutely enough light for raising vegetables and all kinds of green plants.

My research is that caloric dense staple crops simply will not grow on Mars even BEFORE a dust storm hits.  Remember that the NASA estimates of 24 m^2 growing area per person are based on growing these kinds of crops.

The only thing that could be grown are winter type vegetables and don't think you appreciate the incredibly low caloric density of these vegetables aka Spinach, Kale, Beets etc.  Carrots and Beets are only of the most dense foods that can grow in low light and a person would need to consume 5 kg of them a day to reach 2,000 calories.  The required growing area gets enormous at this kind of yield.

Lets look at Biosphere 2 to see how incredibly hard this is.  They had 2,000 square meters of highly fertile soil and were able to grow high caloric density foods (bananas, papayas, sweet potatoes, beets, peanuts, lablab and cowpea beans, rice, and wheat) but had trouble feeding 8 people.

The light levels outside were some of the best on Earth being in nearly cloudless Tucson Arizona, but the glass and structure of the enclosure blocked significant amounts of this (50-60% total but quite unevenly) and reduced yield, indeed most commercial greenhouses block 10-20% of the outside light, a fact completely ignored by greenhouse advocates here who are only considering the outside light on Mars.

Read this paper http://globalecotechnics.com/wp-content/uploads/2011/08/Advances-Space-Research-1995-Food-and-Nutrition-Bio2-Silverstone-and-Nelson.pdf

Note table 3 and the HUGE reductions in yield of crops when they receive low light levels.
Title: Re: Scaling Agriculture on Mars
Post by: nadreck on 04/23/2015 12:29 AM

Note table 3 and the HUGE reductions in yield of crops when they receive low light levels.

So add concentrating mirrors
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/23/2015 07:17 PM
As even the abstract says in Biosphere 2 they did not fertilize their crops. Also, Biosphere 2 had a shortage of CO2 for photosynthesis, it was being sequestered by the setting foundation. As we were taught in General Agronomy course a plant grows as much as it is limited by its most limiting factor. In the Mediterranean basin it is most often water, in Virginia it is Nitrogen. In Biosphere 2 it was lots of stuff, but not solar radiation. I believe but cannot prove (though I'd be willing to work on it if somebody offers me the facilities and the funding) that Net Primary Productivity inside a Martian Greenhouse will be sufficient to grow multiple plant species, not just leafy greens. We know that increased CO2 concentration in the atmosphere, both the free atmosphere and inside greenhouses, leads to fewer water requirements and thus reduced irrigation needs. I would not be surprised if it leads to reduced radiation needs, but as I said, we need more experiments. I seriously doubt that we would want our Mars colonists to be Mole Men, leaving all their life in a hole and would rather have them able to go and enjoy plants among the lifelessness of the surface rather than entombed by 6 walls.

BTW I think the term would be aquaponics rather than aquaphonics, unless the users are also listening to the sounds that the water and its creatures make (Phone = voice, Ponos = Pain, care). It sound like an intriguing concept to take greater advantage of nutrients and NPP though while I see fish animals necessary for survival at Mars, I see them eating plant remains rather than specially grown food. Growing animals with feed just for the animals take 3 to 4 times the land that just feeding the grains to humans. Still, increasing productivity and adding animal nutrients while minimizing space and volume is at least intriguing.
Title: Re: Scaling Agriculture on Mars
Post by: Lar on 04/23/2015 09:03 PM
This is a fascinating discussion and I commend the participants.

However when I see phrases like " literally the most ridiculous romanticism-of-mars argument I have ever heard" I tend to get concerned... that's not how ladies and gentlemen speak to each other. Please remember to be excellent to each other. Thank you.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/23/2015 09:28 PM
From what my son said tilapia are the fastest growing fish for consumption.  From eggs to ready to eat is only about 3-1/2-4 months.  They are plant eaters, young starting on algae, then the older ones eat plant material in the water.  So they could eat plant scraps or wastes from plants grown for food.  Win win.  Fish waste is used for fertilizer pumped from the bottom of the tanks and cycled through the hydroponics to feed the plants strained by the plant gravel and returned to the tank clean and oxidized. 
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/23/2015 10:31 PM
As even the abstract says in Biosphere 2 they did not fertilize their crops. Also, Biosphere 2 had a shortage of CO2 for photosynthesis, it was being sequestered by the setting foundation. As we were taught in General Agronomy course a plant grows as much as it is limited by its most limiting factor. In the Mediterranean basin it is most often water, in Virginia it is Nitrogen. In Biosphere 2 it was lots of stuff, but not solar radiation. I believe but cannot prove (though I'd be willing to work on it if somebody offers me the facilities and the funding) that Net Primary Productivity inside a Martian Greenhouse will be sufficient to grow multiple plant species, not just leafy greens. We know that increased CO2 concentration in the atmosphere, both the free atmosphere and inside greenhouses, leads to fewer water requirements and thus reduced irrigation needs. I would not be surprised if it leads to reduced radiation needs, but as I said, we need more experiments. I seriously doubt that we would want our Mars colonists to be Mole Men, leaving all their life in a hole and would rather have them able to go and enjoy plants among the lifelessness of the surface rather than entombed by 6 walls.

BTW I think the term would be aquaponics rather than aquaphonics, unless the users are also listening to the sounds that the water and its creatures make (Phone = voice, Ponos = Pain, care). It sound like an intriguing concept to take greater advantage of nutrients and NPP though while I see fish animals necessary for survival at Mars, I see them eating plant remains rather than specially grown food. Growing animals with feed just for the animals take 3 to 4 times the land that just feeding the grains to humans. Still, increasing productivity and adding animal nutrients while minimizing space and volume is at least intriguing.

Again NO, they suffered from low O2 levels NOT low CO2 levels.  The CO2 levels were consistently HIGH, ranging from 1,000 to 4,500 PPM, that 3x to 12x the normal atmospheric levels.  Still well below human toxicity levels fortunately, but a veritable FEAST for plants, their is absolutely no argument that CO2 levels were a limiting factor for food production.  The paper CLEARLY states that light levels were the primary limiting factor, I strongly recommend you read it before speculating further.

I'm going to call any suggestions that food systems compromise their ability to make food so they can be 'ascetically pleasing' ridiculous, we are dealing with life or death matters here, society COLLAPSES when food supplies are interrupted.  It 'would be nice' to go take a stroll on the surface of Mars without a spacesuit but it would be certain DEATH, a poorly designed agricultural system is a massive liability.  Living as a 'mole-man' is better then starving with a nice view.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/24/2015 12:58 AM
That the paper clearly states something, does not necessarily mean that it is true. I would suggest you read the Arizona Cooperative Extension guidelines for fertilizing small grains:

http://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1346.pdf

Did the Biosphere 2 inhabitants provide even the 166 N/acre require for 5000  lb/acre at 12% grain protein? Definitely not, they only used in field organic sustainable sources that are far far lower. In general Biosphere 2 was not built as an agricultural facility but as an ecological sciences facility. It was not intended to maximize crop productivity, hence the huge limitations it faced, let alone the problems uncovered after the facility was sealed. Most certainly we can provide through design far higher solar radiation than what was available in the limited farmland of the terrarium in Arizona and at a better angle.

We want the psychological stability of our colonists, it must not be ignored. The Soviets managed to get a cosmonaut to stay 12 months at Mir only around the second try, the first one actually developed depression and had to return to Earth.

I agree, it is a life and death situation to provide sufficient food for the colonists, and we cannot rely only on finicky light bulbs, available only from Earth resupply until we set up a factory. 20.000 hours (life of LED lamp for normal applications, I do not know for the corrosive environment of a greenhouse) is @ 1500 days at 13 hours a day, we will need at least a hundred lamps to cover the whole foliage in a sufficiently sized greenhouse. If earth resupply comes at conjunction, thus 780 days, we need to be receiving 50 lamps on each resupply just for the greenhouse. The sun rises every day on Mars, no matter what we do, does not require resupply from Earth. Yes, we will need to clean the windows regularly from the outside, but I am sure we can make a robot to do that, like those that have been built to clean skyscrapers. Yes, during dust storms which from what I remember from Opportunity are quite seasonal and do not happen that often solar illumination levels drop. I also remember though that whenever Spirit and Opportunity have been on a ridge, the winds have removed the dust. Ridges sound like a great location to set a greenhouse, cleaning winds, positive topographic effect. I am not claiming that supplementary illumination is unnecessary, far from it. I am saying that we should not rely exclusively on engineered solutions when the nearest industrial base becomes available every 2 years. The ISS gets 8 resupply missions every year, we can't have that on Mars. We will already have high needs for all the pumps to run the greenhouse, though being mechanical devices it will be somewhat easier to 3D print. Yes, we can substitute Mars sunlight exclusively with lamps, but is it wise to do so?
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/24/2015 02:35 AM
Nothing like having a debate with a person that just jumps to the next argument with full confidence without even the faintest acknowledgement that their last argument was utterly debunked.  And that scientific papers who's conclusions they don't like are less creditworthy then their own speculations.

Their is no evidence that Nitrogen was a limiting factor for Biosphere 2, their 'soil' was practically pure cow manure which proved to be too rich, that's why they had O2 levels dropping from excessive respiration of bacteria in the soil.  They were indeed using organic growing practices which means they were composting everything in sight (including their own waste) and tilling it into the soil, that is a considerable source of nitrogen, just because they are not applying chemical fertilizer doesn't mean they not fertilizing or that they were nitrogen limited.  Modern farming practices (which is what an extension service is giving) require continual application of chemical fertilizer because soil microbes are decimated and biomass is removed with each harvest which cuts off the nutrient cycle between the top growth, animals and soil, under organic practices that cycle continues and you maintain soil nutrients.

In any case ANY argument you can possibly confabulate about soil, water, air limitations are refuted by the FACT that they are rotating their crops around in different plots and at different times of the year such that light levels are the ONLY variable, and they show huge yield variation on that factor.

All indications are that you have still not read the paper so I will simply paste the critical table here

Crop            Total Mol Light     Mol per Day    Kg of Yield  (all per m^2)

wheat 1                  679                  6.4              0.04
wheat 2                1534                10.5              0.09
wheat 3                2022                16.4              0.24

Sweet potato 1    1258                     7               1.26
Sweet potato 2    3047                14.6                1.8
Sweet potato 3    3419                22.7              2.88


Also your LED lifespan is decades out of date, LED' you buy at Walmart last 50k hours and they are pushing 100k for newer ones with improved heat-sinks.  https://www.rabweb.com/100k.php  If replacements need to be sent we will send JUST THE DIODES to be plugged into the fixture and diodes are tiny, so a mere shoebox of supplies once a decade is what's going to be needed, this will be several pages down in the spare-part resupply manifest.

On a general note the obsession with 'total self sufficiency' is completely misplaced and unrealistic, a colony is not an 'ark' (yes I know Elon has been confusing many people on this), a colony is going to be receiving MASSIVE and continual injection of supplies and materials for decades, possibly centuries before it becomes anywhere near self-sufficient, indeed it is never MEANT to become self-sufficient, colonies exist to create trade relations with the parent and both ultimately become inter-dependent.  The 'colonies' of North America are still quite interdependent with the Old world.

Sunlight is 'free' but structures are NOT as I've said a million times, how can you be so fixated on some free photons while ignoring all the cost and difficulty of putting them DIRECTLY onto the plants.  The greenhouse plastic is going to need to be replaced every few years right off the bat, that's FAR more mass then a few burned out LED's.  Nickles in front of steam rollers are 'free' but it's not wise to try to collect them either.
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 04/24/2015 02:41 AM
LED lifetime varies a lot with how hard you drive them.  Back off a bit on the drive current and keep them well cooled and they last much longer with better efficiency than if run near the rated limits.  The typical LED lightbulb for consumer use has nowhere near enough heat sinking for maximum longevity.

All that said, reliance on supply from a distant source is still a potential liability.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/24/2015 04:12 AM
The lack of radiation inside the terrarium of Biosphere 2 was due to the architecture of the terrarium, not lack of sun in Arizona. They even say it on page 54: "The glass and space frame structure of the IAB eliminated 50-60% of the ambient light" If anything under the solar conditions of Arizona you need to add paint to the top of greenhouses to avoid excessive radiation for the plants, and the thermal problems it causes. 4 year PET cover under Greek conditions lasts 6, the darkening due to UV radiation is actually welcome. Typical greenhouse transmissivity is closer to 80-90% rather than the 40-50 of Biosphere II.

Oh, I did read the paper. I also remember a magic word from composting class: Nutrient availability. When microbes are decomposing organic matter they bind the N until decomposition is done and it is not available to the plants, until decomposition is over. Having composts as your soil substrate is not a guarantee of high N availability, it only guarantees that soil pH will be close to 7. When a crop is grown, it selectively modifies the elemental and microbial composition of the soil. Go ask the farmers who grow the same crop every year about how that particular's crops pests get ever worse, leading to diminishing return every year until it stabilizes after some 5 or 6 years, hence the need for crop rotations. When you do an experiment on a single factor, you do at least 4 repetitions of each tested factor level in order to reduce the uncertainty about related factors. I did not see on the paper details in the repetitions. I did not see any soil test mentioned on the paper. I did not see any irrigation water analysis on that paper. On commercials greenhouse I remember far higher yields than those on the paper, alas I am no longer affiliated with a university to pull out the appropriate table out of a book, there were definitely several things other than radiation that were affecting the yield in Biosphere 2 but I do not see them in detail.

Agronomy is not engineering, there is a complete alphabet soup of factors explaining you experiment, some of which can be taken into account through statistical methods and some you cannot. Rule of the thumb is that 70% is good enough, we accept that 30% we do not know what is happening despite having the best model. In Portugal on the analysis I did on the hydroponic greenhouse's yield there was stronger correlation with the previous week's Potential Evapotranspiration that with that of the current week's PET. Why? For one thing there was a mysterious drop around week 6, which might have to do with a strong pest attack inside the greenhouse. In reality I do not know.

Acrylic greenhouse cover material, clear PVC more properly, have a field proven lifetime of decades under terran conditions. As for putting them over plants, well, I would tell you use Google Earth to zoom to Campo de Almeria or Ierapetra and see how farmers have successfully managed to put them there. There is a whole industry on setting up greenhouses on earth. I think setting up the 6 walls of the greenhouse with resin is easier that digging a whole a hole in the ground and covering it. Internal structure will need to be changed, but that is also the case in a hole on the ground. My emphasis on self sufficiency comes from agricultural experience. As a greenhouse farmer from Marathon put it when I went there on a field trip as an undergrad "your knowledge from agricultural machinery class will prove very useful when your heater breaks down on a Friday night with a snowstorm coming and your plumber cannot come before Monday morning". On the one hand complexity sucks, on the other hand on another planet there is an entire level of complexity necessary just to make things happen. We do not have the N fixing bacteria to be able to avoid fertilizer, we need to produce it. We cannot go to the nearest shop and buy a light bulb when it opens, the nearest shop is pretty far away. A farmer needs to work as autonomously as possible, even greenhouse farmers. Farming communities after all tend to be -or at least derided by us city folk- in the middle of nowhere, there is a real advantage to self sufficiency.

Yes I admit my knowledge of LED as lamps for greenhouses is limited. When I took that course in college as an undergrad they were not out yet, sodium was the most efficient light bulb out there at 40% though it was not that popular because of its spectrum. In any case we did not really place an emphasis, under Greek conditions you need to add light only for photoperiodism, rather you needed to reduce light for thermal control at times. Artificial lighting is a North European problem. Still, in northern Europe, despite the horrible illumination, they still prefer supplementary lighting to sunlight compared to fully artificial systems.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/24/2015 06:55 AM
Artificial lighting is a North European problem. Still, in northern Europe, despite the horrible illumination, they still prefer supplementary lighting to sunlight compared to fully artificial systems.

Great contribution. Thanks for that. I love it al but want to emphasize your last sentence. That part is often overlooked when talked about artificial lighting. It usually is supplementary, mostly to have longer days to start growth cycles early, when days are still short.

Artificial light may be the way to go on Mars when there is abundant cheap nuclear energy. But even then I would be surprised if it is used for all crops.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/24/2015 07:00 AM
About Biosphere II. I was fascinated by the experiment. But it has no place in discussion about a martian biosphere. Except as a warning, how not to do it.

Biosphere II was about putting a lot of biology into a glass jar and hoping it would work without knowing how. A martian biosphere will be controlled in every aspect from growth to nutrient cycles. We will need to lear a lot to make that happen efficiently.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/24/2015 07:48 PM
Biosphere II was a very interesting albeit a bit over-publicized experiment to see how to create a full scale model of the entire globe. They did not have just one biome, they had 6. End result was "jack of all trades master of none", but we learned quite a bit about relationships, human and ecological, inside the terrarium. The Martian biosphere will not be as natural or as sustainable. I try to speak only for what I know and I try to extrapolate from what I am familiar. While working on my thesis on hydroponics as an undergrad I did run into papers by JSC which I did read and try to follow up, but I never run into papers about Biosphere II as Mars analogue. Below is a link to a Dutch fully artificial lighted greenhouse:

https://www.youtube.com/watch?v=Ct3dK2_ksvk

If you notice closely it is a tomato plant NURSERY, not a production greenhouse. Be aware that the Netherlands is twice the size of New Jersey (somewhere between Maryland and Virginia) with a population of 16 million, there is a serious shortage of space leading to constant innovations. I do not claim to know the whole truth, as Socrates I try mostly to be aware of my ignorance.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/24/2015 11:20 PM
Northern Europe still has this thing called SUMMER in which they are getting all their lighting needs meet from the sky, remember Mars is like a never ending winter light level so your going to have every reason to put in supplemental lights just as they use in Northern Europe, and once your dependent on artificial lighting your going to want to reduce your number of dependencies by going full artificial and eliminating dependency on natural light.  Also they also have this thing call AIR in Northern Europe which means a greenhouse (or any structure for that matter) is infinitely cheaper and easier to maintain then any pressurized area on Mars will be.

Do not confuse yourself by thinking that because Mars has lots of available 'land' that it allows you to ignore structural square footage costs, free land != free structures, how many times to I have to repeat this.

Your still trying to dismiss Biosphere 2, now on some grounds that it had 'other ecosystems' in it, this is simply not relevant to the results of the farming efforts, these other ecosystems are in different sections of the Biosphere and are not taking away from the farming output, if anything they provided supplemental foods, the farming area in Biosphere 2 only provided 80% of calories.

Both you you are trying to dismiss Biosphere 2 because you don't like how it reflects on the difficulty of food supply from a greenhouse and the amount of growing area, time and labor involved.  Biosphere 2 had a lot of mistakes going into it that is certain but none of them can be blamed for low food production other then the low light levels which are EXACTLY what you are guaranteed to get on Mars. 

If you know the first thing about growing then you know that what mattes is LIMITING FACTORS, and Bisophere 2, and indeed tons of other Agronomy research shows that light levels are the significant limiting factor in plant growth when you get to the kinds of light levels present on Mars.  This is child's play simple, light is energy, food is concentrated energy, you can't have the later without supplying the former.

Growing space needs in a purely naturally lit Martian greenhouse would need to be >250 m^2 per person in Biosphere 2 to achieve just the near starvation diet they managed.  Artificial light by being more intense reduces the growing area, as well as allowing it to stack vertically, so your pressurized volume and structural needs drop by an order of magnitude.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/24/2015 11:39 PM
Mars doesn't have rain or cloudy weather, so the sun is constant every day.  They do have an occasional dust storm.  Being constant it too can and should be used and maybe supplemented so it doesn't take a lot of power.  When the space station was first built, after a while, the astronauts wanted a window to be able to see outside and they put one in one of the units.  They also built a cupola.  I'm saying people can't live underground without seeing outside at least some time, unless they have some huge spaces and heights.  People can't live in close quarters and small places forever.  So why not let it be greenhouses for some crops and for a break to look outside sometimes. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/25/2015 01:04 AM
I've been thinking that perhaps this would be a great time to calculate what the area would be necessary to feed one person. Let's go with a Dutch greenhouse tomato crop. In the paper attached, working in an enriched atmosphere of CO2 at 1000 ppm, they had a yield of 56.2 kg of tomatoes/m2 of greenhouse. This was in a 1400 m2 greenhouse

Now according to USDA, here,

http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2682/2

those 56.2 kg of tomatoes have 10,135 calories. So, if we are eating exclusively tomatoes, that would last you 4 days? For 365 days in a year you would this need 91 m2 of greenhouse space. Now on the internet there are websites claiming to have reached in the Netherlands 90 kg/m2, which would reduce the space to 60 m2. Of course I have no expectation of eating 13 kg of tomatoes a day and, after all, most of the calories in the salad come from the olive oil, tomatoes are selected to be low in calories. There are far richer foods in calories per m2 grown. I am not a nutritionist and I do not know what a balanced diet on Mars looks like, but 250 m2 per colonist looks plenty to me, considering that there is always dead space in a greenhouse. So, if we have 4 colonists, MarsOne first mission style we need one 1000 m2 of Greenhouse space. If we use this cover material
http://www.greenhousemegastore.com/product/deglas-acrylic-panel-16mm-clear/plastic-greenhouse-film
1000 m2 weight around 450 kg, and assuming another 1000 m2 for the side panels (very generous), we will need one ton for the greenhouse and structure. Since Mars has 3/8 the gravity of earth, we will need far less structure on the greenhouse. Of course we will need some other materials to make the greenhouse work, such as pumps, filters, thermal blankets, etc.

BTW in Northern Europe summer is a horrible time of the year, it rains almost every day. I know, I have been there repeatedly. That is why they come to the Mediterranean to have their vacations in our sun.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/25/2015 07:53 AM
All indications are that you have still not read the paper so I will simply paste the critical table here

Crop            Total Mol Light     Mol per Day    Kg of Yield  (all per m^2)

wheat 1                  679                  6.4              0.04
wheat 2                1534                10.5              0.09
wheat 3                2022                16.4              0.24

The table proves that growing wheat in darker conditions reduces the yield. What remains unproven is even equatorial Martian sites have inadequate natural lighting.

The table also proves that either wheat 3 was grown also in too dark or it suffered some other problem, lack of nutrients most likely. 2400kg/ha yield is abysmal. IMO Biosphere 2 is poor comparison here because it was more about biodynamic Noah's Ark than high intensity farming, so the construction may not be optimized for the latter.

Still waiting for that PI-curve btw.

And why is nadreck's suggestion of concentrating sunlight to the greenhouse being dismissed? The discussion seems to ignore that moleman farming also concentrates sunlight in a more complicated way, requiring large area of solar paneling to create electricity for the led lighting. Or is nuclear reactor assumed.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/25/2015 08:21 AM
Northern Europe still has this thing called SUMMER in which they are getting all their lighting needs meet from the sky

I'd trade many North European rainy summer days for Martial equatorial sunshine.

Quote
, remember Mars is like a never ending winter light level so your going to have every reason to put in supplemental lights just as they use in Northern Europe,

The lighting in Martian equatorial sites compares to roughly 60N latitude here during equinox. In reality Mars wins because there aren't the rainy days there.

Quote
Also they also have this thing call AIR in Northern Europe which means a greenhouse (or any structure for that matter) is infinitely cheaper and easier to maintain then any pressurized area on Mars will be. Do not confuse yourself by thinking that because Mars has lots of available 'land' that it allows you to ignore structural square footage costs, free land != free structures, how many times to I have to repeat this.

Has anyone suggested that Martian greenhouses wouldn't cost more per unit of area than here on Earth? If not this is a strawman. Keep this condescending attitude up and you don't have to repeat anything on this site very long...

Quote
If you know the first thing about growing then you know that what mattes is LIMITING FACTORS, and Bisophere 2, and indeed tons of other Agronomy research shows that light levels are the significant limiting factor in plant growth when you get to the kinds of light levels present on Mars.  This is child's play simple, light is energy, food is concentrated energy, you can't have the later without supplying the former.

Please give a reference with proper high intensity yields, like >10t/ha for wheat.

Title: Re: Scaling Agriculture on Mars
Post by: kdhilliard on 04/25/2015 06:03 PM
Please give a reference with proper high intensity yields, like >10t/ha for wheat.

Are you guys familiar with NASA's Advanced Life Support Baseline Values and Assumptions Document (http://ston.jsc.nasa.gov/collections/trs/_techrep/CR-2004-208941.pdf) (PDF)?  Section 4.2 Biomass Subsystem gives a general discussion of hydroponic crop growth models and includes some nominal growth rate values.  Section 4.2.3 presents the Modified Energy Cascade Models for Crop Growth, which models growth of nine different crops as a function of CO2 concentration (330 - 1,300 ppm) and photosynthetic photon flux (200 - 1,000 umol/m^2s -- twice that upper limit for rice and wheat, half for lettuce).  The math itself is not so difficult (it does include a couple of 25 term polynomials in powers of [CO2] and [PPF] between ^-1 and ^3, but the coefficient matrices are fairly sparse), though given the low, fundamental level of the model, there are a good number of equations to be worked through to get a final yield answer.

BioSim (https://svn.traclabs.com/biosim/), the life support simulation package written by TRACLabs for NASA JSC, uses this Modified Energy Cascade Model for its plant grown modules, but I believe that you need to construct an entire habitat model maintaining an atmospheric balance in order to get any crop yield values.  I'm not aware of a stand alone module which simply allows for the visualization of crop growth values as a function of [CO2] and [PPF].  If I don't find one I will consider writing it.  BioSim is open source (GPL), its latest development version is available a its GitHub repository (https://github.com/scottbell/biosim/), and contributors are welcome.

Last year's MIT Mars One Feasibility Assessment (http://web.mit.edu/sydneydo/Public/Mars%20One%20Feasibility%20Analysis%20IAC14.pdf) resulted in the fiasco of the erroneous "Crew dead in 68 days" meme (a bug in their BioSim derived biological simulation code was entirely responsible for the excess O2 production without necessary CO2 injection in their baseline model; they told me last November that they will release a corrected paper sometime this spring), but their method of crop mix selection to support a crew of four with 200 m^2 actual crop area (stacked so that they occupy a smaller footprint) is worth a read.

~Kirk
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/25/2015 06:16 PM
Actually it looks like commercial wheat yield of is around 3 tons per hectare, http://www.statista.com/statistics/237726/global-wheat-yield-per-hectare/  so no idea where your getting 10 tons from.  The highest light level in Biosphere 2 is still falling short of that and it's clear that the reason is light levels, all the yield numbers are scaling with light in a nearly linear fashion.

Mars doesn't have rain but it has consistent dust, both in the air and settling out on the greenhouse (this is not Dust storm dust, this is just the constant background dust).  The greenhouse glazing material will block a minimum of 15% of the light, and more like 20-25% once you account for structural members.  These are the things people are ignoring, by the time you subtract all these factors the light levels are going to be very low.  Not to mention that we probably won't be at Mars equatorial sites because they are bone Dry and we absolutely have to have water.


Has anyone suggested that Martian greenhouses wouldn't cost more per unit of area than here on Earth? If not this is a strawman. Keep this condescending attitude up and you don't have to repeat anything on this site very long...

Did you not catch Agean's estimate of 1 kg per m^2 for a rigid structure in which he just multiplies the mass of a commercial greenhouse acrylic panel?   That fits the description of a wildly unrealistic estimate that ignored the fact that Mars has no air pressure.  He didn't even account for a floor, or anything to even hold up the panels when doing the estimate.
Title: Re: Scaling Agriculture on Mars
Post by: Burninate on 04/25/2015 07:34 PM
Actually it looks like commercial wheat yield of is around 3 tons per hectare, http://www.statista.com/statistics/237726/global-wheat-yield-per-hectare/  so no idea where your getting 10 tons from.  The highest light level in Biosphere 2 is still falling short of that and it's clear that the reason is light levels, all the yield numbers are scaling with light in a nearly linear fashion.

Mars doesn't have rain but it has consistent dust, both in the air and settling out on the greenhouse (this is not Dust storm dust, this is just the constant background dust).  The greenhouse glazing material will block a minimum of 15% of the light, and more like 20-25% once you account for structural members.  These are the things people are ignoring, by the time you subtract all these factors the light levels are going to be very low.  Not to mention that we probably won't be at Mars equatorial sites because they are bone Dry and we absolutely have to have water.


Has anyone suggested that Martian greenhouses wouldn't cost more per unit of area than here on Earth? If not this is a strawman. Keep this condescending attitude up and you don't have to repeat anything on this site very long...

Did you not catch Agean's estimate of 1 kg per m^2 for a rigid structure in which he just multiplies the mass of a commercial greenhouse acrylic panel?   That fits the description of a wildly unrealistic estimate that ignored the fact that Mars has no air pressure.  He didn't even account for a floor, or anything to even hold up the panels when doing the estimate.
The obvious solution to dust on a planar or cylindrical sheet window is to brush that dust off periodically, if the wind doesn't do it for you.  We have a very good idea how that dust affects flat surfaces like that, because the solar panels we mounted on rovers lasted so unexpectedly long, and it doesn't seem to be prohibitive.

Reflective solar concentrators without much serious design consideration should be fairly effective at least up to 2-3x concentration, replicating Earth-grade sunlight.  For much more than that you'd need to design the farm around them.

A commercial greenhouse acrylic panel doesn't have to deal with substantial overpressure, but a Mars greenhouse has the benefit of substantial overpressure.  Inflatable monocoque structures can be made very lightweight.  A Centaur wouldn't be able to hold together under its own empty weight on Earth if it wasn't pressurized.

I don't think it's obvious which way we should go, natural light or artificial light, for a colony - there are too many unknowns.  What does seem clear is that in any scenario that we'd be okay running the first few hundred people to Mars and back to Earth, we would have ample opportunity to test farming apparatus onsite experimentally, while eating vacuum-packed, freeze-dried, canned, irradiated, and frozen astronaut food.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/25/2015 10:53 PM
I think I will be reading the Advanced Life Support Baseline Functions documents, when I get the time. It looks quite interesting and I wish I did have access to it when I was an undergrad. On Earth, greenhouses do not have a floor, there is foundation set for the structure so that we can set up the panels and hold the growing plants but otherwise, all you can really expect on the floor is tarps. All that I have read on structure on Mars (which granted, is not really much) says that overpressure due to atmospheric pressure inside the structure gives support. I am under the impression that just properly gluing the cover material and making sure that it does not have leaks is enough to make the structure statically stable, so long we maintain earth level air pressure. Structure would be necessary for attaching the plants, but even with hard plastic the issue would be making sure that the greenhouse does not blow up. Then again I am not an engineer. Light transmissivity of the material I linked to is 86% for the first year and 83% at the 10th year, it shouldn't be hard to have a greenhouse with a total transmissivity in the order of 70-75%.

US wheat yield is relatively low, because US agriculture is mostly dry. Irrigated wheat is often higher than dry wheat. I would suggest this pages: http://www.earth-policy.org/books/fpep/fpepch7 . France, Germany and the UK had an average yield in the last 5 years or 7-8 t/ha, and this is the national average. Also consider that hydroponic crops often have higher yield than field crops.

There was a postdoc position at USDA Beltsville MD experimental station that was to use cropsim that I heard about on ASA 2013 and I wanted to apply for that. It would fit great with my doctoral research. Alas it came out after I got my current job, which pays better than that position.

EDIT: The link above at the earth policy institute does say that US yield is 10 t/ha, my bad for skimping before linking.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/26/2015 02:03 PM
Are you guys familiar with NASA's Advanced Life Support Baseline Values and Assumptions Document (http://ston.jsc.nasa.gov/collections/trs/_techrep/CR-2004-208941.pdf) (PDF)?

...

Last year's MIT Mars One Feasibility Assessment (http://web.mit.edu/sydneydo/Public/Mars%20One%20Feasibility%20Analysis%20IAC14.pdf) resulted in the fiasco of the erroneous "Crew dead in 68 days" meme (a bug in their BioSim derived biological simulation code was entirely responsible for the excess O2 production without necessary CO2 injection in their baseline model; they told me last November that they will release a corrected paper sometime this spring), but their method of crop mix selection to support a crew of four with 200 m^2 actual crop area (stacked so that they occupy a smaller footprint) is worth a read.

~Kirk

The MIT study references that NASA paper and IIRC it was discussed in the Mars One thread.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/26/2015 02:10 PM
I do know one thing, hydroponic crops do not taste good.  I've tasted tomatoes grown hydroponicly and some out of my backyard garden.  There is a big difference.  I know it might have to be done on Mars, but I do think that a foot or so of soil made from fish or small animal waste, as well as processed human waste, would make food a lot more tasty and it could be blended with Mars soil.  If it can't be, then natural fertilizers applied to some type of hydroponics, might be ok.  Artificial fertilizers are not that tasty.  I blend in leaves ground up by my lawn mower into the soil.  So, maybe leaves from small fruit trees and bushes could be ground up and blended with the animal waste.   I do know that peach, pear, apple, plumb, lemon trees, as well as blueberry, and fig bushes do not grow very tall.  Also blackberry, raspberry, and strawberries are small vines.  Then there are grapes.  I do also know that wheat and corn can grow well in eastern US that gets more rain.  One English acre of wheat 208' x 208', in the eastern US can provide a family of 4 enough bread for a year.  I think hectare is 100m x 100m. 

I do think high yield crops per unit of space will be grown first, followed by others as well as trees, wheat, corn, and rice when the greenhouses or underground units are built.  After water, air, and fuel production infrastructure is in place, food production will become a very high priority.  Exploration for natural resources on Mars will come, maybe even robotically while building is going on.  A lot of things will have to be brought from earth to build, grow, and eventually take advantage of Martian resources.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/26/2015 02:11 PM

US wheat yield is relatively low, because US agriculture is mostly dry. Irrigated wheat is often higher than dry wheat. I would suggest this pages: http://www.earth-policy.org/books/fpep/fpepch7 . France, Germany and the UK had an average yield in the last 5 years or 7-8 t/ha, and this is the national average. Also consider that hydroponic crops often have higher yield than field crops.

Exactly, the minimum principle mentioned earlier means you can't get world record wheat yields in the main US wheat farming areas. If the annual rainfall supports only 3t yield it's not economically viable to attempt higher, irrigation is often too costly for staple crops. The minimum principle also contains rule that one resource cannot substitute another. Cannot compensate for too little moisture with excessive fertilizing, actually that is harmful for the plants, ecology and wallet.

Global average yield also contains all third world countries where farmers cannot afford intensive fertilizing, pesticides and fungicides even if the weather would allow it.

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EDIT: The link above at the earth policy institute does say that US yield is 10 t/ha, my bad for skimping before linking.

That was corn yields.
Title: Re: Scaling Agriculture on Mars
Post by: kdhilliard on 04/26/2015 07:41 PM
Advocates of surface greenhouses need to keep ionizing radiation exposure in mind.

MSL Curiosity's Radiation Assessment Detector (RAD) findings during its first 300 sols on Mars suggest a Galactic Cosmic Radiation (GCR) dose equivalent rate of 232 mSv/yr (23.2 rem/yr) on the surface.(Hassler, 2013 (http://www.michaeleisen.org/blog/wp-content/uploads/2013/12/Science-2013-Hassler-science.1244797.pdf))  The US Nuclear Regulatory Commission (NRC) sets a maximum occupational expose limit for radiation workers of 5 rem/yr and many Department of Energy (DOE) labs set an administrative limit of 2 rem/yr.  For Martian greenhouse gardeners, these limits would be reached after working 1888 hrs/yr (5.3 hrs/sol) and 755 hrs/yr (2.1 hrs/sol) respectively.

These might be workable numbers, but they seem a poor trade for the privilege of working in a surface greenhouse.  I'd rather limit my exposure during mundane work and save it for the occasional surface excursion or sunset view from an observation tower.

BTW, Hassler's paper projects a subsurface GCR dose of 2.9 mSv/yr (290 mrem/yr) 3 meters down.  The RAD numbers are based on measurements taken during the recent solar maximum, which, weak as it was, still diverts some GCR.

~Kirk
Title: Re: Scaling Agriculture on Mars
Post by: Port on 04/26/2015 07:44 PM
is this based on the linear-threshhold thing? (which i suspect)
because if yes than you can pretty much discard those limits, not only in my, but in a lot of other much more credible peoples opinion
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/26/2015 08:36 PM
is this based on the linear-threshhold thing? (which i suspect)
because if yes than you can pretty much discard those limits, not only in my, but in a lot of other much more credible peoples opinion

I fully agree with you. However I think they will need to do extensive tests before they can actually dismiss these thresholds. But even then, these numbers look great, better than I expected. No farmer works full time 365 days a year in the fields. So even adhering to those limits it should not cause any problems.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/26/2015 10:36 PM
No farmer works full time 365 days a year in the fields. So even adhering to those limits it should not cause any problems.

The migrant workers that pick the crops certainly do.  The hourly limitations that radiation would force are yet another reason why transparent greenhouses are a bad idea.  But this debate is increasingly looking like a lost cause because greenhouse proponents are simply weeded to the idea and will not consider alternatives.
Title: Re: Scaling Agriculture on Mars
Post by: kdhilliard on 04/26/2015 11:26 PM
is this based on the linear-threshhold thing?
The NRC does accept the Linear No-Threshold hypothesis "as a conservative model for estimating radiation risk"(NRC (http://www.nrc.gov/about-nrc/radiation/health-effects/rad-exposure-cancer.html)), so yes, the LNT most likely did inform their choice of occupational exposure limits.  I don't intent to enter the LNT debate here, though I believe the majority of that debate centers around the predicted effects of small doses to large populations, and that few researchers, even amongst those who reject the LNT, doubt that some statistically significant Excess Relative Risk of cancer would be found in populations receiving individual lifetime occupational doses of a couple hundred rem (a couple Sv), which is the level we are talking about here.

Having not made these calculations before, I didn't know how the numbers would fall, and I offered the NRC and DOE limits purely for comparative purposes.  These exposure levels would entail additional risk, but they are not necessarily high enough to exclude surface greenhouses purely on those grounds.  I should clarify that when I wrote, "they seem a poor trade for the privilege of working in a surface greenhouse," I meant that I believed the risk of that level of radiation exposure to outweigh the psychological benefits of the view, as suggested above.  Were a surface greenhouse chosen for reasons of efficiency, I would gladly accept such doses for the privilege of tending any greenhouse on Mars.
Title: Re: Scaling Agriculture on Mars
Post by: Coastal Ron on 04/27/2015 12:07 AM
...because greenhouse proponents are simply weeded...

Doubt you intended, but funny enough to point out...   :D
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/27/2015 01:29 AM
Taste in a tomato is an issue of variety and carbohydrate content. That a tomato grown in the back yard would taste better than a hydroponic tomato, usually means that the back yard tomato is of a tastier variety. There is significant literature, quote usually in the introductory chapters to hydroponic cultivation, that under the same insolation and variety hydroponic tomatoes taste better than field grown tomatoes. This derives both from blind tasting tests and from Brix measurements. Degrees Brix (see also article in Wikipedia) is a quantitative measure of carbohydrates in a solution, in our case tomato juice and has the advantage of, well, quantitativeness. We have reached to point that when tomato researchers talk of taste they actually mean Brix content, just like when Remote Sensing scientist talk greenness they actually mean NDVI. There is another issue on which hydroponics has advantage over field grown tomatoes: fertilizer use efficiency. There is no direct difference in taste (and I mean blind taste) on whether the nutrients come from organic or chemical fertilizer though there is an indirect effect because organic sources modify soil pH towards 7 and make more soil nutrients available. However Nitrogen Use Efficiency (NUE) in soil grown crops is in the order of 40-50% while for hydroponics (closed looped systems rather than open loop run to waste) it is closer to 70%. There is also a very Martian problem: it is easier to keep a completely hydroponic system isolated from the Martian biosphere, which I believe exists, that a soil based system.

Now in the greenhouse that I worked in Crete during my internship in the summer of 2001 we would work inside the greenhouse from 6 am to 11 am the latest, already from 10 am it was too hot despite having all windows open and the fans at full power. In Portugal a couple of years later the agronomists and workers of the greenhouse which had a fully mature crop would spend around 5-6 hours a day in the greenhouse tops, and that included things that normally are not done in a commercial greenhouse, such as measuring tomato diameter. In Mars it would overheating would be a great surprise, but even for crops that produce in waves such as vegetables, as opposed to grains which produce all at once, workers would not show up for harvest more than twice a week and rarely work 8 hours. Of course I am talking about a ~ 1000 m2 greenhouse, if in the mega greenhouses of 1 or 10 ha there are workers there all the time it makes sense, they have more crops to harvest. Unskilled farm labor is highly seasonal, with greenhouses being one of the rare cases where full time employment is available. Otherwise though farm labor tends to be necessary during planting (if not using a fully automated planter), irrigation (somebody needs to move hoses) and harvest. In a greenhouse and horticultural crops in general manual labor is mostly needed for harvest. Radiation can be a very serious issue, a greenhouse due to its thin cover has 4 times the heating need of a house of the same size, so I cannot even guess what high energy radiation would look like. I think though if we have 4 colonists and a 1000 ha greenhouse we can do a monthly rotation, one colonist can pick vegetables twice per week and then next one the next week etc.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/27/2015 02:25 AM
No farmer works full time 365 days a year in the fields. So even adhering to those limits it should not cause any problems.

The migrant workers that pick the crops certainly do.  The hourly limitations that radiation would force are yet another reason why transparent greenhouses are a bad idea.  But this debate is increasingly looking like a lost cause because greenhouse proponents are simply weeded to the idea and will not consider alternatives.

No they don't. It's seasonal work. They work for some time, maybe 12 hours a day, 7 days a week. But not nearly all year long, only during harvesting seasons. True though, when conditions are as controlled as they would be in a martian greenhouse, harvesting season could be spaced all over the year. But even then average workload would be not nearly every day of the year 8 hours or more.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/27/2015 06:25 AM
In Mars it would overheating would be a great surprise,

The underground moleman farms would surely need a cooling system of some sorts. Pumping a lot of energy into a styrofoam igloo guarantees things heating up.

Quote
but even for crops that produce in waves such as vegetables, as opposed to grains which produce all at once,


If you want cereals in regular waves shorter than nominal growth time all you have to do divide the area for that crop into sub-areas in different growth phase.


Quote
workers would not show up for harvest more than twice a week and rarely work 8 hours.

Can you tell any figures for things like how much tomato or something a proficient greenhouse worker can pick in an hour?

I'm familiar with open field wheat and barley farming. For me it usually takes less than half an hour to plants seeds in one hectare, varies by the plot size and shape. Applying weed control etc takes about five minutes per hectare. One hour for a combine to harvest the hectare, over here 5t/ha is nominal, got 7t/ha from winter wheat last fall which was nice despite challenging summer. Those figures with modestly sized farming equipment. Current world record for harvesting wheat with single combine is about 800 tonnes in 8 hours.

https://www.youtube.com/watch?v=Y5I04EObZNo (in UK, average yield 9.95t/ha!)


Btw the surface radiation on Mars seems to be about as much as people get in Ramsar, Iran. (http://en.wikipedia.org/wiki/Ramsar,_Mazandaran)
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/27/2015 08:51 AM
The greenhouses would probably be covered at night for one, to shield from meteorites.  Two, to hold in heat.  Also, they could be worked at night harvesting or planting.  I think some type of either retractable shield, like Kevlar or a closable shield that reflects extra sunlight into the greenhouse during the day.  I'm not saying a worker would stay in the greenhouse all day long, but would use it for looking outside occasionally during the day to keep from feeling so confined in an underground living area/working area.  Also using direct sunlight, plus a little reflected sunlight is free and wouldn't require extra electricity for lighting. 

I know of a farmer who built a 1,000' long greenhouse, and placed his plants on a long conveyor belt ran off a 5hp motor.  He put seeds in trays that had about 1' of soil on one end each day.  Then moved the conveyor once a day.  At the end were full grown crops.  So he was planting on one end and harvesting on the other.  He also had lights for night growing.  This method can be used for any small crop like carrots, turnips, spinach, even bush peas and beans.  He had no chemical insecticides.  He once planted this same crop on 200 acres, and hired 20 migrant workers to harvest the 200 acres.  After building this greenhouse, he produced the same amount of product in a year as the 200 acres did.  His electric bill was higher, but it was offset by only having two full time workers help run the greenhouse along with his son and himself.  He converted his 200 acres to pasture and raised cattle.  This greenhouse method with the cattle brought him in more money that the previously planted 200 acres and produced more food per acre otherwise. 

Greenhouses on Mars could be done this way and the work only done on each end and the workers wouldn't be exposed to as much radiation as the ends could be semi-underground or have water tanks above the working area. A lot of different crops could be grown this way, planted and harvested daily.  This would allow for fresh food to be harvested continuously.  They wouldn't have to be very wide, but long and slender.  They could also have double or triple pane glass with small panels for ease of repair. 
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/27/2015 07:19 PM
No farmer works full time 365 days a year in the fields. So even adhering to those limits it should not cause any problems.

The migrant workers that pick the crops certainly do.  The hourly limitations that radiation would force are yet another reason why transparent greenhouses are a bad idea.  But this debate is increasingly looking like a lost cause because greenhouse proponents are simply weeded to the idea and will not consider alternatives.

No they don't. It's seasonal work. They work for some time, maybe 12 hours a day, 7 days a week. But not nearly all year long, only during harvesting seasons. True though, when conditions are as controlled as they would be in a martian greenhouse, harvesting season could be spaced all over the year. But even then average workload would be not nearly every day of the year 8 hours or more.

It's always time to harvest something SOMEWHERE, that's why migrant field workers migrate.  Your working conditions and regulations for field workers are probably better in Germany, but in the US and Mexico and Canada is is basically a never-ending hand-2-mouth cycle of day-labor work that takes people across thousands of miles from southern Mexico to Canada following the harvest.

Astronauts have a 8 hour work day on the ISS, I see no reason to think it would be less on Mars, the only way you would get around the radiation limits it to give a person a mix of work hours in shielded area of the habitat.  Something between 3 and 6 hours under shielding and 5 to 2 hours without.  That's not beyond reason as I am sure you can find enough work to do in shielded spaces but it cuts into the specialization that would come with dedicated agricultural work as well as cutting into the amount of available EVA hours that can be performed as so many un-shilelded hours are being eaten up by food production.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/27/2015 07:49 PM
I wish I did have quantitative labor requirements for greenhouses. I would refer to my final project I did at the Instituto Superior D'Agronomia, but there is a major caveat: there was a lot of experimental work. If you ever get to Lisbon and actually climb at the Tapada de Ajuda and make it to the library, its one of the very few theses dealing with tomatoes. A greenhouse is a labor intensive (rather than a capital intensive) enterprise, popular in areas with a shortage of land, which is why it quite rare in the North America. The best source for quantitative data would be an appropriate professor of horticulture in a land grant university, who can also point you to the appropriate source in the National Statistics. Also textbooks on greenhouses and hydroponics have a tendency to give some soft numbers. In general though like solution mixtures, the best sources written tend to be grey literature (not peer reviewed) in local publications and in the local languages.

I've heard on mega-greenhouses with plants being in different growth phases, the mechanized greenhouse with the conveyor belt does not surprise me though I've never seen of something like that with my own eyes. In small greenhouses (and 1 ha even is not so big) farmers would rather move the workers around with harvest carts rather than the plants to the workers. Choices in mechanization depends on available capital, labor and time. I have seen thermal blankets put over the plants in mechanical rails below the glass in greenhouses in Ierapetra, the idea being to reduce heating needs in winter. Perhaps for Mars on observatory or garage style cover would be better at night than blankets, the hard plastic propose though is tough enough for hail. I think it becomes an issue of budget mass, the Martian atmosphere does protect from small meteorites though of course far less than earth.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/27/2015 09:48 PM
The greenhouses would probably be covered at night for one, to shield from meteorites.  Two, to hold in heat.  Also, they could be worked at night harvesting or planting.  I think some type of either retractable shield, like Kevlar or a closable shield that reflects extra sunlight into the greenhouse during the day.  I'm not saying a worker would stay in the greenhouse all day long, but would use it for looking outside occasionally during the day to keep from feeling so confined in an underground living area/working area.  Also using direct sunlight, plus a little reflected sunlight is free and wouldn't require extra electricity for lighting. 

Are you completely incapable of understanding that MASS to make structures out of is incredibly costly on Mars, you keep pounding this 'free light' nonsense like it's some miracle, it ain't we have other ways to collect light, they are called solar panels and we can make thin-film panels that are a fraction of a kg per m^2.

Look at the numbers from Advanced Life Support  Baseline Values and Assumptions Document posted earlier.  It says 10 kg per m^3 of unshielded pressurized volume, and that's NON-transparent.  A greenhouse is going to need to be ~2 m tall at the very least and that means 20 kg per m^2 of growing area inside as an absolute lower limit using plastics, glass would be even heavier as would all the other protective covers, secondary reflector mirrors and other patches desperately being applied to the concept.   A 1000 m^2 greenhouse is going to thus mass a minimum of 20 Metric tons.

For 20 Metric tons a solar system would (according to http://systemarchitect.mit.edu/docs/cooper10.pdf) cover 125,000 m^2 and yield HALF A MEGAWATT averaged over the whole day, that collects a lot more 'free light' then the greenhouse, even after all the conversions of 10% panel efficiency and 50% LED efficiency (which is actually low ball, they are hitting 75% now in blue LEDs, though we will be using mostly red which has been lagging behind because blue is the focus for use in white-light lamps http://www.soraa.com/news/soraa-large-lamp-gen3-022414)  (which is offset by the fact the LED's put out only PAR when natural sunlight is only half PAR), your looking at 12.5x the radiation and energy delivery to the crops even if the greenhouse were 100% transparent which it won't be.

Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 04/27/2015 10:50 PM
Are you completely incapable of understanding that MASS to make structures out of is incredibly costly on Mars, you keep pounding this 'free light' nonsense like it's some miracle, it ain't we have other ways to collect light, they are called solar panels and we can make thin-film panels that are a fraction of a kg per m^2.
Im generally a fan of underground (or under ice) but there is also the cost of excavating the volume or covering in meters of regolith. It might be easier to get sheer acreage with pipes carrying algae on the surface for the bulk of calories. Im not pretending I have done the math to compare those costs.

A bit more sci-fi.. could it be possible to grow root vegetables without leaves? Im talking about a sort of cybernetic potato where instead of leaves you have connections that deliver the sugars the leaves would have provided, created through some more efficient method.

Anyone know anything about the limits of using light tubes or fibre optics to move light underground directly? Im most interested in this for somewhere like Ceres where you do not need to worry about cloudy days and diffuse light.
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 04/27/2015 11:47 PM
Regarding radiation in a greenhouse: Looking at fiber optics as a limit on achievable glass clarity, at least in theory a window several meters thick could have the needed clarity.  Yes that's a lot of mass.  But I'm also assuming glass would be  produced from local materials rather than imported from Earth.  A key step in high transparency class is removing certain problem elements, like iron.

A concentrator mirror with smaller area windows is also possible.  With a dual reflection path light could be admitted without a direct path for cosmic radiation or meteoroids to reach the window.  If the greenhouse is laid out on an east-west line you may not even need sun tracking on the mirrors.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/28/2015 04:21 AM
On earth there are several crops produced indoors with no natural light, most infamously cannabis. The power consumption for the lights is so outrageous, that the police can easily find them by monitoring power consumption. LED lights are not generally used in greenhouses on earth, while they are available for sale most greenhouses that have illumination use sodium or fluorescent lamps. Acrylic (i.e. clear PVC) cover is light (=not heavy), durable, transmissive and require very little structure for the greenhouse, and I am talking about Earth. Now if we go for glass cover on Mars we will most likely find the raw materials on Mars far easier than for plastic (though we will need to set up the industrial infrastructure to produce glass), glass has a proved stability for centuries but we will need a heavier structure in the greenhouse. If we go with the underground solution, beyond digging the hole and disposing of the material dug out we will consume more power, be more dependent on the reliability of the electrical system (e.g. brownouts) and also will need to dispose of the excess heat coming out of the greenhouse room. The choice is up to the mission designers.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/28/2015 04:57 AM
You can not possibly think that the production of glass (which is far more infrastructure and energy intensive then you can possibly imagine) on Mars is less energy intensive the pushing a few meters of regolith around with a bulldozer???  Were talking about 3m thickness here, that's only the depth of a normal basement, you place or build your structure in that ditch and then push the regolith back over it, it costs literally NOTHING in energy terms.

And no we do not need to considered the mass of the bulldozer because we MUST do this for the rest of the habitat that people live in to protect them from GCR, so if you have this capability your equipment is already paid for and you ALSO build your growing area the same way.

Your observations about cannabis would be relevant IF it was still 1990 and people were using High pressure Sodium lamps, but thouse are obsolete and vastly less efficient then LED's which ARE exploding in use (too grow you know what).  The stories of cops use electric bills to find people growing cannabis in the house are true but irrelevant when a normal homes electric use is so low compared to what we will be needing on Mars for all kinds of purposes.

And if you think a brown-out is going to kill the crops then were Shit our of luck because NIGHT would do the same thing, power systems would need to be down for DAYS before crops die from lack of light and if that is the case the colonists are going to have frozen or asphyxiated long before they starve.  For that matter ANY agricultural system that doesn't have emergency rations that can see us through a crop failure is fatally flawed.  Please stop with these pathetic straw-man arguments about dependency on electricity, they make as much sense as saying we shouldn't be dependent on pressurized air on Mars cause that 'might fail'.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/28/2015 05:52 AM
@Impaler

You think the energy consumption for producing glass is vast? It is nothing compared with the energy consumption for growing crops under artificial light.

That said, producing quality glass is a process that needs a lot of resources. Google float glass. It requires a large amount of tin, that fortunately is not consumed so a one off. But it lasts long and the material can be easily recycled. So the energy input pays off over a long period.

Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/28/2015 06:25 AM
What should be contemplated is how much weight is given to locally resourced materials vs Earth imported lightest weigh high-tech. Mileages probably vary wildly because it's more of a value choice question than result of some exact physical equation. Some may have sights in full self-sustaining while others are thinking early phases with heavy dependency from Earth. Talking past each others might ensue if this is not clarified.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/28/2015 04:19 PM
When trying to design for Mars we try to use Earth analogues as much as possible. We do not have a good baseline on the actual cost and lifetime of LED lights in the highly corrosive environment of a greenhouse on Earth; the inside of a greenhouse is hot, humid and has all sort of chemicals, nothing like your house. We do not know what the actual expenditure of time, energy and construction material will be for anything will be on Mars. However for those of us who live in places where cement rather than wood is the local material have learned to be very wary of construction. Sure you will not need the archaeological service to do an excavation in your plot of land before you build and you will not need as much steel to make the place earthquake proof but construction work still is time consuming: Digging which might mean explosives or a pneumatic drill. I don't know what will be the connecting material for Mars concrete, though be aware that on earth we also include water, sand, and coal ash in the material. I have had to go and wet concrete as it was setting so that it would not crack. The Mars Pioneer website mentions special resin as connecting material. Also, one you build, you are fixed, modifying walls is hard.

Greenhouses are light and proven on Earth. We have great knowledge for the lifetime and survival of several materials and how the environment is modified inside the greenhouse. Fitting and setting a greenhouse is far easier than construction of anything. Expansion does not require digging up walls, though it might require depressurization and repressurization. In the end it is an issue of infrastructure and weight, and where will that infrastructure be. What is the development plan for the colony? Where do we gain what ability? It is easier to grow the plants first inside the earth launched habitat, much as there will be an air composition issue, this is why this thread is entitled "Scaling Agriculture". Do you want to send 1 ton of material to Mars for the first greenhouse? I would say it is worth it. What industrial infrastructure is necessary for the second, third or fourth greenhouse and when do you gain it? Like the whole "Journey to Mars" project, at this point what we best can do is identify what is necessary and try to solve the holes in the planning, offering options rather than certainties.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/29/2015 12:03 PM
I've been in commercial greenhouses, yes they are hot in summer, and vent with retractable roofs and with fans.  The usually do not use chemicals in them as there is no need for insecticides with screened and glassed windows.  On mars they can be covered at night with a retractable roof of some sort, even Kevlar for meteorites and radiation.  Mars is much cooler than earth, even cold in most places, so the greenhouses could bring some heat in, how much depends.  Usually in winter on earth, the greenhouses do not have to be open or vented due to the cold. 

Also, people will not live in the greenhouses on work in them to plant and harvest food.  So radiation would be kept to a minimum, because most or all the work could be done with the covered greenhouse at night. 

The greenhouses I've seen aren't very wide, but are very long, as plants are moved as they grow.  Planting on one end, harvesting on the other.  Golf carts are used to drive the distance in them.  Some are only about 24' wide.  Some a little wider.  Also small multi-pane windows would allow for easier replacement, and a quick ability to seal off any damaged units.  The sky could be monitored for anything headed their way.  Anything large would have to be destroyed, smaller and covers could be retracted.  With narrow greenhouse construction, they could be added onto for an almost infinite length, as materials are brought from earth, or made with Mars' raw materials.  Some plants require more UV light than others also, and would require UV lighting if underground, which would take more electricity, than retractable awnings made of Kevlar. 
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 04/29/2015 04:54 PM
I have a persistent vision of greenhouses on Mars doubling as arboretums/parks for human psychology benefit.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 04/29/2015 05:45 PM
Skimming the thread again I didn't see the main argument against "greenhouses" that has been pretty extensively mentioned in studies on the subject: leakage.

Greenhouses on Earth don't worry about it because it doesn't really matter but unless you greenhouse is a single structural unit (NOT panes of glass) you leak. A lot.

As for the "artificial-vs-natural" light strawman, (and IS very much a strawman argument, usually from both sides :) ) you would usually have a non-transmisive building to reduce your radiation exposure both for people and plants. Light wells and tubes are cheap and easy to make and provide "natural" light along non-linear paths so avoid the radiation issue. And if you think meters-thick glass is "easy-and-cheap" to make you will find that microns thin reflective surfaces can be far cheaper.

Further there seems to be an idea of large scale agriculture which is rather silly to begin with. It will be small, modular and dispersed for several reasons but the main ones are redundancy, isolation, rotation control and provide as little variation in atmosphere exchange as possible. How small and modular depends on your exact requirements but to get an idea there have been several experimental production set ups using hydro and aero-ponics that used 40' ISO containers as a base module. (Most of these have been done in Israel, including a "turn-key" commercial flower production unit where seeds and nutrient pallets are inserted in one end and potted flowers are dispensed from the other the unit being fully automated)

Automation is another area where it is somehow assumed that human labor will be 'cheaper' on Mars and the opposite it true instead. Food production and most life support plant maintenance and operations will be automated as much as possible. The trend here on Earth for quantity/quality greenhouse production has been moving in that direction for decades with the only limiting factor economically being that human labor on Earth can still be vastly cheaper than automated systems. With the continued rise of poly-culture production operations (such as aqua-ponics, the combination of fish farming and plant production using hydroponics) automation is becoming more prevalent as cheap "unskilled" labor is less applicable.

In any decently designed colony there will be plants and growing units throughout as there is an obvious and well documented correlation to human well being and access to growing things in the environment. Planters, "air-quality" walls and water recycling artificial "wetlands" will need to be spread out and diversified to ensure long term life support and quality of life needs. There's a lot of good reasons why these systems will NOT be your main food crops, however there are a lot of good reasons for them to be PART OR your food production as well as life support system.

If this stuff has been addressed and dismissed I' apologize but its stuff that's been discussed over and over again with a LOT of presumptions and assumptions on both side which for the most part overshadow the real issues.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/29/2015 06:53 PM
I've seen experiments where a 12x16' greenhouse coupled with a 4'x6'x8' tilapia fish tank can produce enough vegetables for a family of 4 for a whole year and have fish one day a week for a year.  This isn't much space.  Now, on Mars it might have to be slightly larger due to the limited sunlight or supplement with artificial light.  Now with this small a space, one can easily repair a greenhouse. 

I figure a triple pane replaceable panels in case of breakage.  I could see a hardened glass outside pane, a plexiglass middle pane, and a glass inside pane.  If something broke the outer pane, the plexiglass might be able to stop further breakage.  Then the astronaut could go outside and replace the broken pane.  If the panes are small enough, if one broke inside, and emergency snap on panel could be placed over the broken area before something bad happened.  It could be magnetic with a rubber seal.  Framing could be light weight thin steel.  Glass panes on the outside could be attached with some type of quick connect/disconnect screws quarter turn fittings. 

Grains initially could be shipped from earth along with dehydrated or canned meats.  Greenhouse units could be added to the original one for length for future grain production.  One acre of wheat can provide a family of 4 for a years worth of bread. 

The greenhouses could be placed on top of a water tank, with the water tank on top of the living areas.  The water would provide radiation protection for the humans living working areas.  From what I have read only about a foot or two of water can provide the radiation protection.  Being above the living areas would also provide gravity fed plumbing for the lower area.  Fish tanks could be placed almost anywhere and have bottom pumps to recycle the bottom waste to the plants above.  Also with the greenhouses on top higher up, dust would be less of a problem, but could be blown off with a fan and dust filtering of the air when necessary.  Greenhouses could have a nighttime Kevlar cover that would retract during the day. 

I think at least aquaponics would need to be started asap when setting up a colony.  Eating canned, MRE's, and dehydrated food will get old.  Having fresh veggies and fish weekly would be nice.  Frozen food could be brought from earth since space is cold, and Mars will be cold.  Any excess food grown on Mars could be frozen in case of greenhouse failure, or fish failure.  Later chickens will probably have to be brought in order to supply fresh eggs and chicken.  Even small eatable animals like rabbits could supplement the food supply.  All animal waste would go to supply plant production and even methane production.  Chicken waste is now dehydrated fed to cows since it is only half digested.  It can also be fed to catfish and used as fertilizer.  The average American chicken today fits in about one cubic foot of space almost their entire life.  They eat and lay eggs.  Once their production drops, they are killed for food.  Even their feathers can be ground up and processed for protein for fish. 

This is just some ideas I had. 


 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/29/2015 07:15 PM
Your typical well built greenhouse on Earth is quite airtight, to the point that CO2 gets depleted in the morning very fast, if the sky is not overcast three hours max. Greenhouses require ventilation even in the middle of winter for CO2 and humidity: during the night temperature drops leading to relative humidity of 100% and dew condensation. While water on PET is desirable since it improves heat retention (PET, unlike glass or PVC, is clear to IR radiation) it is also quite undesirable because it leads to a good environment for fungal infections. Greenhouses will actually open windows and put cold air in the middle of the night and heat it rather than retain day air in order to reduce relative humidity from 100% to 25%. Greenhouse plant remains have a reputation of being loaded in phyto-chemicals (e.g. pesticides), farmers spray quite often because the greenhouse environment is not only great for plants but also their pests. The last part creates issues in composting, which are solvable. The use of organic fertilizers derived from the crew will also cause emerging contaminant issues (e.g. chemicals that act as sex hormones) and do not be surprised if we run into intersex tillapia in aquaponics, just as we have all those hermaphroditic frogs in America's water streams. Recent finding are that 10% of frogs in US streams are transgendered due often to contaminants derived from insufficiently digested biosolids. Now, in terms of one big versus many small, we get more space for the same cover material with one big greenhouse as opposed to many small. Also with big internal space we get better heat buffer for the night (I am always talking about Earth here where radiation is sufficient to heat the greenhouse in the day pretty fast). The first principle of greenhouse design is maximize transmissivity, which is why I do not see large multilayer multimaterial cover. I do see though the shape being close to a circle rather than long so as to maximize area for the available cover material. A greenhouse with plants will be part of food production system, I do see a space for aquaponics or lagomorphs or chickens so long they eat the remains and we do not grow food explicitly for animal consumption. Transported for from earth is not just boring for the crew, there is the issue of complex nutrients such as vitamins not surviving the trip to Mars leading to "space scurvy". We will definitely need to grow part of the food locally, if only for the micronutrients
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/29/2015 08:08 PM
Your input on greenhouses and their problems is much appreciated, thanks.

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Now, in terms of one big versus many small, we get more space for the same cover material with one big greenhouse as opposed to many small.

It depends. The material requirement for tensile strength increases linearly with size. So your statement is true assuming tiled transparent material with the same size. It would not be true for the materials providing the tensile strength.

I see small diameter long tunnels of plastic sheets with built in reenforcement fibres as a simple and efficient solution. BTW as you mention PET as material. PET can be coated with a very thin layer of glass. That should make it infrared retentive. Good for the night but may lead to overheating during the day. A tradeoff.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 04/29/2015 09:37 PM
Your typical well built greenhouse on Earth is quite airtight, to the point that CO2 gets depleted in the morning very fast, if the sky is not overcast three hours max. Greenhouses require ventilation even in the middle of winter for CO2 and humidity: during the night temperature drops leading to relative humidity of 100% and dew condensation. While water on PET is desirable since it improves heat retention (PET, unlike glass or PVC, is clear to IR radiation) it is also quite undesirable because it leads to a good environment for fungal infections. Greenhouses will actually open windows and put cold air in the middle of the night and heat it rather than retain day air in order to reduce relative humidity from 100% to 25%. Greenhouse plant remains have a reputation of being loaded in phyto-chemicals (e.g. pesticides), farmers spray quite often because the greenhouse environment is not only great for plants but also their pests. The last part creates issues in composting, which are solvable. The use of organic fertilizers derived from the crew will also cause emerging contaminant issues (e.g. chemicals that act as sex hormones) and do not be surprised if we run into intersex tillapia in aquaponics, just as we have all those hermaphroditic frogs in America's water streams. Recent finding are that 10% of frogs in US streams are transgendered due often to contaminants derived from insufficiently digested biosolids. Now, in terms of one big versus many small, we get more space for the same cover material with one big greenhouse as opposed to many small. Also with big internal space we get better heat buffer for the night (I am always talking about Earth here where radiation is sufficient to heat the greenhouse in the day pretty fast). The first principle of greenhouse design is maximize transmissivity, which is why I do not see large multilayer multimaterial cover. I do see though the shape being close to a circle rather than long so as to maximize area for the available cover material. A greenhouse with plants will be part of food production system, I do see a space for aquaponics or lagomorphs or chickens so long they eat the remains and we do not grow food explicitly for animal consumption. Transported for from earth is not just boring for the crew, there is the issue of complex nutrients such as vitamins not surviving the trip to Mars leading to "space scurvy". We will definitely need to grow part of the food locally, if only for the micronutrients

First of all you need to understand that Earth greenhouse experience is almost totally irrelevant to what will be required anywhere but on Earth. (If you wish to get technical it CAN be applicable to Venus at the 1atm gas pressure level) Operations will be similar but circumstances and construction will be vastly different. The "closest" terrestrial experience is that of the greenhouses in Antarctica and THOSE are surrounded by a vastly more benign environment than that found on Mars. (Container gardening is a more practical experience base than actual greenhouse gardening for the circumstances) This by the way is NOT my opinion, people have studied this subject quite a lot though the information is not well collated or collected for easy reference. Artificial means to move air, water, and other materials will be required.

A "well built" Earth greenhouse on Mars would be useless in the extreme. It would be vacuum within seconds, frozen in minutes and irradiated in under an hour. You require a pressure vessel of some type and materials limitations mean the fewer openings the better under the conditions. This does NOT mean that you are forced to use "artificial" light as you can pipe that in. But you will have added heat because the sun alone will not be enough. You will probably have to include some artificial light sources to extend and supplement the available sunlight. You will have fans moving the air because like the inside of any structure "natural" convection will be insufficient to provide proper air movement. You will have pump to move water and nutrients around as standard fertilizer will be impractical. IF you are using soil it will be sterilized and chemical stable and isolated from the surrounding soil. (Most likely you will either be using aeroponics or pelletized soil as a growing medium for hydroponics.

One big versus many small: Your argument is based on a false premise, Earth experience. Many small is more survivable and has a higher viability than one large. It will survive the loss of one or more "small" areas where the loss of "one-big" loses all capability at once. (guckyfan's note on material requirements is another good point) Further you will occasionally have to "vacuum" a segment to reset conditions favorable to mold, mildew, and rot as they build up within the segments and smaller allows you to do that without greatly effecting the overall system. This will also be required to avoid the various issues with contamination build up in the system. (Which you pointed out)

Randy
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 04/29/2015 09:58 PM
I've seen experiments where a 12x16' greenhouse coupled with a 4'x6'x8' tilapia fish tank can produce enough vegetables for a family of 4 for a whole year and have fish one day a week for a year.  This isn't much space.  Now, on Mars it might have to be slightly larger due to the limited sunlight or supplement with artificial light.  Now with this small a space, one can easily repair a greenhouse.

Depending on the system it would probably be more like inside a Quonset hut with a couple of concentrating skylights but the dimensions would be a bit "different" as I seem to recall you need more plant space for proper air exchange. (You'd stack the planting space)

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I figure a triple pane replaceable panels in case of breakage.  I could see a hardened glass outside pane, a plexiglass middle pane, and a glass inside pane.  If something broke the outer pane, the plexiglass might be able to stop further breakage.  Then the astronaut could go outside and replace the broken pane.  If the panes are small enough, if one broke inside, and emergency snap on panel could be placed over the broken area before something bad happened.  It could be magnetic with a rubber seal.  Framing could be light weight thin steel.  Glass panes on the outside could be attached with some type of quick connect/disconnect screws quarter turn fittings.

Thing is you want as few of these as you can possibly manage. Each "pane" has four sides that can leak (and they will) and the pane itself. Plus you want to avoid direct (straight) paths which is a freebe ride into the structure for radiation.

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Grains initially could be shipped from earth along with dehydrated or canned meats.  Greenhouse units could be added to the original one for length for future grain production.  One acre of wheat can provide a family of 4 for a years worth of bread.

We've grown enough wheat in hydroponics units to produce bread on far less than an "acre" of actual space. You just need to stack it vertically instead of horizontally and modularize the planting areas.

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The greenhouses could be placed on top of a water tank, with the water tank on top of the living areas.  The water would provide radiation protection for the humans living working areas.  From what I have read only about a foot or two of water can provide the radiation protection.  Being above the living areas would also provide gravity fed plumbing for the lower area.  Fish tanks could be placed almost anywhere and have bottom pumps to recycle the bottom waste to the plants above.  Also with the greenhouses on top higher up, dust would be less of a problem, but could be blown off with a fan and dust filtering of the air when necessary.  Greenhouses could have a nighttime Kevlar cover that would retract during the day.

My favorite design was in The Millennial Project where the "water-tank" was actually our dome, held up mostly by internal air pressure. The thickness though was enough that even on the Moon the light was significantly reduced and the main living areas had to be recessed into the walls of the "crater" the house was built in. (There were some significant materials problems as well but the basic design with a solid, regolith covered "roof" and central light shaft would work much better) In reality though you really don't want a LOT of water over your living space for the rather obvious reasons :) Leaks with "normal" roof tanks can be disasters, now imagine there's a lot MORE water up there :)
(IIRC it took about a meter of water or more to provide semi-adequate radiation protection I'm pretty sure a couple of feet won't do it) I really need to put together a decent representation of the "house-in-a-hole" concept as applied to space...

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I think at least aquaponics would need to be started asap when setting up a colony. Eating canned, MRE's, and dehydrated food will get old.  Having fresh veggies and fish weekly would be nice. Frozen food could be brought from earth since space is cold, and Mars will be cold. Any excess food grown on Mars could be frozen in case of greenhouse failure, or fish failure. Later chickens will probably have to be brought in order to supply fresh eggs and chicken.  Even small eatable animals like rabbits could supplement the food supply. All animal waste would go to supply plant production and even methane production. Chicken waste is now dehydrated fed to cows since it is only half digested.  It can also be fed to catfish and used as fertilizer. The average American chicken today fits in about one cubic foot of space almost their entire life. They eat and lay eggs. Once their production drops, they are killed for food. Even their feathers can be ground up and processed for protein for fish.

Chickens, ducks and other fowls have been suggested before, one thing the L5 Society found out is that given a "choice" you really want compact, CLEAN meat production and that turned out to be hamsters and fish. I never understood why they had such a hard time with the idea of algae as a basic foodstuff but they did and went out of their way to find another "source" of protein. Today I suspect we can do better but chickens are not really something you want "cooped" up with you in an enclosed environment if you can at all help it. (Ducks are worse)

This is where I hold out much hope for "carniculture" grown meat because I really hate the idea of having to process my own burgers :)
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This is just some ideas I had. 

Other than insisting on a 'greenhouse' I think they are a good start :)

Randy
Title: Re: Scaling Agriculture on Mars
Post by: Burninate on 04/29/2015 10:03 PM
I've seen experiments where a 12x16' greenhouse coupled with a 4'x6'x8' tilapia fish tank can produce enough vegetables for a family of 4 for a whole year and have fish one day a week for a year.  This isn't much space.  Now, on Mars it might have to be slightly larger due to the limited sunlight or supplement with artificial light.  Now with this small a space, one can easily repair a greenhouse. 

"Enough vegetables" or "N kilograms of vegetables" is a recurring trope in discussions of intensive agriculture, and one that's extremely misleading.

Humans can tolerate a diet with zero fresh, frozen, or canned vegetables for a year.  They can, if conditions are right, tolerate an even more extreme plant-less diet (http://en.wikipedia.org/wiki/Inuit_diet) that's nearly all animal fat and animal protein, but that's not convenient for most people.  Most people in the US with low amounts of fruits and vegetables in their diet get by fine on eating a mixture of different cereal grains, plenty of meat, some dairy, and some legumes.  Any remaining deficiencies can be remedied with fortified prepared products, or with multivitamins.  You can forestall scurvy with something as negligible as a single orange or head of lettuce once a month, or get vit C secondhand by eating organ meats.  Vitamin deficiencies are not a problem modern society, with its mixed diet, can even really conceive of.

Caloric deficiencies *are* something we can understand.  Every day of our lives we go through cycles of hunger and satiation.  Fulfilling those needs is what's incorrectly implied when someone says they can feed their family using a garden plot of size X.  And you can't do that.  Because vegetables are an extremely low-grade source of food energy - calories.  A garden that optimizes for the maximum tonnage of fresh produce will end up with things like iceberg lettuce: We bred a variety of brassica to provide no taste, and to use the absolute minimum amount of substance necessary in order to hold together water in a crunchy substrate.  Bundling extra water into a cell doesn't require *photosynthetic work* to be performed, while assembling extra carbohydrates, proteins, fats, or fibers, involves using solar energy to glom carbon & hydrogen together from CO2 & water, along with small quantities of phosphorous, nitrogen, and potassium, to make organic matter.

There are 14 digestible calories in 100g of iceberg lettuce, plus some indigestible cellulose / hemicellulose (fiber).  That means you would need to consume 14 kilograms of it to get 2000 calories a day.  As 1 calorie of carbohydrate or protein is 1/4 of a gram once you dehydrate it, it means that iceberg lettuce is 95% water weight.  Compare 14kg of iceberg lettuce to 500g of flour for the same caloric totals. 

You see this throughout what we think of as fresh fruits and vegetables: While not as extreme as iceberg lettuce, they're all remarkably low caloric density.  When we say "I fed myself using this garden plot", we mean "I fed myself using bread, pasta, beef, chicken, dairy, and also occasionally a head of lettuce or pepper from this garden plot for variety.  It's about like saying "The Matrix runs on body heat and a form of fusion", or "I killed him with one finger [and a .45 ACP Glock]".

"Enough vegetables for a family of 4", therefore, is zero or so close to zero that it doesn't matter (even if that near-zero quantity is surprisingly heavy with water): You're treating vegetables as a special extra, a seasoning rather than a source of energy.  And astronauts don't *need* a seasoning, they need a source of energy, a way to produce edible calories for less mass per calorie than it would cost to dehydrate that food and ship it to Mars in bags, which we're perfectly capable of doing in a nutritionally complete manner.  This is a high standard of feasibility to meet.  On Earth, the UN says: "The minimum amount of agricultural land necessary for sustainable food security, with a diversified diet similar to those of North America and Western Europe (hence including meat), is 0.5 of a hectare per person.".

You're not going to make anything like the goal - providing a substantial fraction of the caloric needs of the crew - from a 12' x 16' greenhouse.  Vegetables are a source of non-pill-form nutrients and fiber and flavor, but those are secondary or tertiary concerns to address long after you've established a food energy caloric baseline.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 04/29/2015 10:15 PM
The sky could be monitored for anything headed their way.  Anything large would have to be destroyed, smaller and covers could be retracted.

Wow. Now we're adding meteor defense systems. Just so we can maintain the illusion that "greenhouses are easy".

You will probably need artificial light even during the peak growing season in summer, you'll certainly need it during winter. You'll need artificial heating during summer nights and winter days, and extreme heating during winter nights. The mass of the greenhouse is an inflatable tube sufficient to hold the pressure against a near-vacuum, requiring significant mass and fairly high vulnerability - it will not be an arched frame mounted on the Martain "soil" and lightly covered with plastic panels. [And that's ignoring the idea that we'd be using metres thick glass panels manufactured on Mars, which really deserves to be ignored.] The atmosphere in the greenhouse will require, in effect, a dedicated ECLSS about as complex as the one for the crew habitat, and will certainly be complex enough that it won't be part of the habitat's ECLSS. It will be a long narrow cylinder, in sections for redundancy and safety, and a single giant circular dome. Multiple insulating layers because of heat loss, but also a single thin layer for transmissivity, plus every night an opaque movable cover system and probably some kind of ground heat-pump storage system. Mirrors running down the entire length, to provide sufficient insolation. It needs to be at about 40 deg latitude for underground water-ice ISRU, and on the equator (and maybe even at the poles), all at the same time...

...And now we need some kind of meteor-destroying protection system. Pew pew pew.

But hey, Martian greenhouses are easy, right? Just a light frame plonked onto the Martian soil with some light plastic panels attached.

This topic is a good example of why I dislike the idea of Mars settlement so much. There's something about Mars that means people get these simplistic fantasy images in their heads (like greenhouses) and even if (slowly, reluctantly, almost by force) they can be made to consider all the hideous complexity of a realistic system, they somehow still revert back to that initial vision of "simple".

It's like there's this weird selective amnesia, where you can (again, slowly, reluctantly, almost by force) get advocates to admit to some particular complexity on some specific issue, but the moment the conversation shifts they literally forget about all the previous problems. Like they can only hold one problem in their heads at a time, all other factors go back to their default of "Mars is simpler". Any other area of space development (LEO, AG, moon, asteroids, etc), they can easily rattle off long lists of complexities all at once. But Mars only ever has one problem, one complexity, everything else is "simpler".

[How many times has someone brought up the image of an astronaut walking around in shirt-sleeves in the greenhouse, gazing out at the hills of Mars... a greenhouse that by now has acquired kevlar panels, is surrounded by mirrors to amplify sunlight, etc etc... You ain't seein' jack. And with a non-breathable atmosphere, you ain't goin' in there without a containment suit and an EVA-buddy. But the moment they stop thinking about a specific problem, it immediately vanishes from their vision, and they're back to picturing simple cheap Earthly greenhouses plopped delicately on Mars.]
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/29/2015 10:17 PM
Also, I didn't mention PVC, I mentioned sandwiched plexiglass (clear) for secondary break protection.  The commercial greenhouses (I helped design the gas heating system) were 500' long and only about 24-30' wide.  They did not use pesticides.  They had screens and outside double doors to limit insects from entry.  Chemicals will not be needed on insect free Mars.  Only seeds would need to be carried up.  If you use fish or small animal waste, as well as human waste to process for fertilizer, no fertilizers will be needed.  Algae can be grown and made into pellets to feed fish and small animals.  Most plastics are useless in UV light, so glass, aluminum, and maybe some steel could be used in construction.  They can be modular for ease of assembly in spacesuits.  As I suggested, wheat, corn, and rice, could be brought up dry for several years until larger growing units could be built.  It doesn't take much space for enough veggies to grow to feed a colony, nor small animals or fish.  If not enough CO2 is produced to supply the plants from human and animal breathing, that can be supplemented with Mars atmosphere.  If not enough O2, then cracking the CO2 or water to get enough for that will already be going on to supply rocket fuel.  It also doesn't take a lot of soil depth for vegetables either.  Even Mars soil can be blended with waste for topsoil, depending on what is in the soil.  Calcium can be obtained from fish and animal bones.  Lime might be a problem, and some might have to be shipped from earth.  A lot of topsoil making material can be from volcanic soils on Mars.  I know the red dust has oxygen and iron in it.  Humidity might be a problem, but that is also a problem on ISS and dehumidifying equipment can take the water out of the air and recycle it for potable water. 
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 04/29/2015 10:35 PM
Aside: I'm surprised that insects haven't been mentioned as a food source. Apparently they are quite simple (ha, I am do irony) to grow en masse and have high "conversion" efficiency.

The settlers don't have to eat the insects directly, they can feed the larva to the fish and chickens to augment the plant matter. Apparently the nearly pure protein larva are not only ideal for fattening up the animals, but because larva tap into their natural foraging instincts, it lowers stress amongst the animals (basically they are happier therefore healthier) which reduces your stress levels.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/30/2015 02:54 AM
With regard to LEDs vs light-pipes, I'm actually rather indifferent as I would consider both of these to be 'artificial light' aka we are not using a transparent structure to let sunlight fall upon the crops at it's unmodified flux density.  Once we use some means to collect light outside and bring it 'inside' and put it onto crops that are stacked vertically we have broken through the flux density limitations of a 'greenhouse' and we are limited only in how large of a collection area we can create AND we can dispense with the difficulty of engineering a transparent structure which means we can bury it for radiation protection.

I think solar/batteries and LEDs will prove to be more efficient collectors then light-pipes primarily because of the mirror type collectors will prove too bulky as they generally need to be pointed to collect good amounts of light and direct it into the pipe.  In addition a battery system will allow us to break out of the natural hours of sunlight, though this is far less important then the earlier flux density as many plants can't tolerate more then 12 hours of light a day.  Some kind of hybrid light-pipe and LED system might be desirable, it might even involve the LEDs being outside on a 'branch' of the light-pipe so the two mix together before coming inside.  This would also keep all the waste heat of the LED outside and extend their lifespan by keeping them as cool as possible.

Paul451:  I think you really put your finger on the kind of 'romantic' mindset I've been dealing with in this thread, every argument I put forward gets deflected with some 'patch' to save the greenhouse idea.  It's to the point of not even arguing that greenhouses are 'simple' proponents are telling me they MUST have them so they can enjoy the view of Mars AND plants at the same time (viewing them separately just isn't ascetically pleasing enough!).
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 04/30/2015 05:53 AM
A "greenhouse" illuminated through a light pipe need not have supplemental heating.  All that light coming in through a small area leaves an equally small window for heat to escape.

A greenhouse on Earth needing ventilation for CO2 balance strongly suggests that agriculture on Mars will need a large volume of air, whether inside the greenhouse or in some coupled structure.  A large volume of atmosphere is also desired as a buffer from various transient conditions affecting it.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/30/2015 06:07 AM
Insects have been mentioned before, twice. I counter proposed that we grow and eat snails, as we do on August 29th every year (decapitation of John the Baptist). I also proposed going for spirulina or chlorella as the first crop on Mars. For the 5th time in this thread I will repeat that the Martian Greenhouse will require its own life support system, separate from the one of the habitat and this is the main reason I propose we keep the facility separate from the living facility. If you prefer I will use the term ECLSS, to repeat myself we most definitely need a separate ECLSS for the plant food growing facility which is to be separate from the human habitation facility. Since we are keeping these two systems separate we might as well have the plant food growth facility as a greenhouse on the surface and take advantage of solar illumination rather than provide all illumination artificially.

PVC (granted, not greenhouse grade material) is being used to carry hot and corrosive fluids with temperature differences of hundreds of degrees from the ambient. I think we can make clear PVC able to withstand the temperature difference between ambient Mars night and plant survival limits. I am fully aware that earth material will blow up balloon style on Mars, I am under the impression that we can make a covering material sufficiently light and rigid (greenhouse clear PVC is very rigid, hard like glass but not so easy to break and can survive hailstorms) to survive the expansion. I am not a materials scientist but having experience from earth conditions I am proposing solutions based on materials that are not often considered by non specialists. I am assuming that we are using standardized panels to set up the greenhouse because that is what we do on Earth, if we want to bring or produce 10 different sizes of panels, I can forgo that assumption.

By definition a greenhouse contains a heat source even if it is digesting manure, if it does contain a heat source it is not a greenhouse but a covered cold growth chamber. On Earth we need heating for the night and rarely for day, I have no doubt that on Mars we will also need to heat during the day since plants are not able to regulate their temperature. Also I know from earth that it is better energetically to heat the plant (e.g. by IR lamp) directly rather than the whole air though on Earth growers prefer to heat the air using gas, oil or pomace due to simplicity and lower capital costs. We will definitely bring pests on Mars no matter how stringent our biological safety controls are, hence our ECLSS needs to be able to change greenhouse air composition radically from phytosanitary reasons, which is another reason why it is best separate from the ECLSS of the human habitat. I have no doubt that supplementary illumination will be necessary, at a minimum for photoperiodism reasons though likely also for photosynthesis reasons. Forced air circulation though (granted, I am unfamiliar with Martian gravity) is usually used only for humidity and temperature control (overheating). Big voluminous greenhouses (over 3 m tall) often do not need forced air circulation, there is sufficient temperature gradient inside it to ensure sufficient natural circulation.

There is an index on how much area of farmland is necessary to feed one person for each country. The US is on top of the list because of its meat rich diet, but there are several countries on the list that manage to produce enough food for a healthy population with less land per person than the US. Since earth shipments will be finite and space under life support is also finite it is best to minimize the area necessary to grow food. The earth analogy on the back of my head are the monks of Mt Athos: the monks try to minimize food imported from outside the Mountain since they have to pay for it, they do not grow animals because their care can come at times they have set aside for prayers (though they do keep pets), they eat fish mostly during feasts and thus eat a mostly vegan diet. Yes not only are they not undernourished (unless they spend too much time doing the Jesus prayer to show up for the meal), several are actually overweight. We can grow sufficient and nutritious food based mostly on plants. As I have said several pages ago several times we do not know what a Mars diet will look like but plants plus tillapia or snails or insects if you prefer can provide it. We can get calories from oleoginous plants, vitamins and minerals from fruits and vegetables which have been bred to be low calories, there are several varieties out there for vegetable that do have higher calories than their cousins you buy at the supermarket. The food that you buy at the supermarket has been selected to meet market demand and can change as it changes: Up to the 1960's pork was the main source of fat, when demand arrived for lean pork in the 1960's we changed to races grown that had only 1/10th the fat of what was sold before. The same is true for fruits and veggies and let me tell you, the old varieties have not died down, they are still kept in the seed and variety collections. We can get proteins from beans or spirulina, starches from tubers etc. First though we need to know what diet we want, what can best survive the growing environment and provide maximum nutrients per volume. I certainly remember from horticulture class (as I mentioned a few pages before) that vegetables provide more nutrients per area which is why I have been talking about them.

I do not claim to know the truth, I give suggestions. Romanticism led to the nation states of Europe and the collapse of oppressive empires, I have no problem with romantic notions so long we can ground them in reality. After all, exploring is a very romantic notion.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 04/30/2015 07:55 AM
If you prefer I will use the term ECLSS, to repeat myself we most definitely need a separate ECLSS for the plant food growing facility which is to be separate from the human habitation facility. Since we are keeping these two systems separate we might as well have the plant food growth facility as a greenhouse on the surface and take advantage of solar illumination rather than provide all illumination artificially.

This is a total non-sequitur, just because growing areas are 'separate' from the rest of the habitats dose not mean they must be on the surface, the separation can be achieved by a mere airtight DOOR.

I don't find anything your saying about construction of a greenhouse or any structure on Mars remotely credible, you admit you have experience only with Earth structures, have no expertise in materials science or pressure vessel engineering and are just trying to say that methods your familiar with on Earth will work because your 'under the impression' that they will work based on flimsy analogs like hail.  That's not a rational basis for YOU to believe something, let alone to convince any of us.

Commentary about what happens INSIDE a greenhouse and what kind of masses/volumes/time is involved in a greenhouse operation would be within your area of expertise and would be met with less skepticism.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 04/30/2015 08:43 AM
With regard to LEDs vs light-pipes, I'm actually rather indifferent as I would consider both of these to be 'artificial light' aka we are not using a transparent structure to let sunlight fall upon the crops at it's unmodified flux density.  Once we use some means to collect light outside and bring it 'inside' and put it onto crops that are stacked vertically we have broken through the flux density limitations of a 'greenhouse' and we are limited only in how large of a collection area we can create AND we can dispense with the difficulty of engineering a transparent structure which means we can bury it for radiation protection.
Off topic, but I guess that lightpipes are no use for improved flux density during a dust storm, and you would have to have complicated tracking for other times. Hence why I was thinking of Ceres with no dust storms and very low axial tilt where you could possibly get away with fixed cylindrical collectors aligned with the equator.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/30/2015 08:57 AM
Skimming the thread again I didn't see the main argument against "greenhouses" that has been pretty extensively mentioned in studies on the subject: leakage.

Any numbers to quantify the problem, like how much gas is expected to leak per length of seal per day? A greater problem in in-space structure where replacement is hard to get. On Mars you pump the leaked CO2, N just back in from the atmosphere. Surely the plants are expected to make O2 faster than it leaks. Leaked water must be either mined from the atmosphere or dig up as ice from the ground.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 04/30/2015 09:08 AM
If you prefer I will use the term ECLSS, to repeat myself we most definitely need a separate ECLSS for the plant food growing facility which is to be separate from the human habitation facility. Since we are keeping these two systems separate we might as well have the plant food growth facility as a greenhouse on the surface and take advantage of solar illumination rather than provide all illumination artificially.

This is a total non-sequitur, just because growing areas are 'separate' from the rest of the habitats dose not mean they must be on the surface, the separation can be achieved by a mere airtight DOOR.

"might as well have" != must, the non-sequitur is your own making.

Quote
I don't find anything your saying about construction of a greenhouse or any structure on Mars remotely credible, you admit you have experience only with Earth structures, have no expertise in materials science or pressure vessel engineering and are just trying to say that methods your familiar with on Earth will work because your 'under the impression' that they will work based on flimsy analogs like hail.  That's not a rational basis for YOU to believe something, let alone to convince any of us.

Commentary about what happens INSIDE a greenhouse and what kind of masses/volumes/time is involved in a greenhouse operation would be within your area of expertise and would be met with less skepticism.

And now that you have displayed excellence in putting AegeanBlue in his place how about sharing us your credentials in this subject?
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/30/2015 04:23 PM
Oh, we do learn how to set up a greenhouse, properly dimension the frame, select the cover material, select the machinery inside the greenhouse such as drippers, lights, blankets, set the automation programs etc. Setting up the growing conditions depends on setting up the entire greenhouse. There is a common aphorism we agronomists have on engineers in that it is pretty obvious when they have designed dairy buildings (instead of agronomists) in that they often make cows walk up and down stairs. The growth facility will be set up by a cabal of scientists with input from various types of expertise, I am willing to share mine and to admit my ignorance and expertise, I would like to hear what is the expertise of others.

I certainly remember the farmers I was controlling (for their subsidy) who had trouble signing their signature due to semi-literacy but were they utterly certain that they know how the world worked in all its details and that they would make a far better Prime Minister than the one currently in power. Producing the best olive oil in the world does not make you the best PM but you can certainly give him good advice him on olive oil, not on foreign policy.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 04/30/2015 08:40 PM
With regard to LEDs vs light-pipes, I'm actually rather indifferent as I would consider both of these to be 'artificial light' aka we are not using a transparent structure to let sunlight fall upon the crops at it's unmodified flux density.  Once we use some means to collect light outside and bring it 'inside' and put it onto crops that are stacked vertically we have broken through the flux density limitations of a 'greenhouse' and we are limited only in how large of a collection area we can create AND we can dispense with the difficulty of engineering a transparent structure which means we can bury it for radiation protection.

I think solar/batteries and LEDs will prove to be more efficient collectors then light-pipes primarily because of the mirror type collectors will prove too bulky as they generally need to be pointed to collect good amounts of light and direct it into the pipe.  In addition a battery system will allow us to break out of the natural hours of sunlight, though this is far less important then the earlier flux density as many plants can't tolerate more then 12 hours of light a day.  Some kind of hybrid light-pipe and LED system might be desirable, it might even involve the LEDs being outside on a 'branch' of the light-pipe so the two mix together before coming inside.  This would also keep all the waste heat of the LED outside and extend their lifespan by keeping them as cool as possible.

A "greenhouse" illuminated through a light pipe need not have supplemental heating.  All that light coming in through a small area leaves an equally small window for heat to escape.

Terraluxe (about the only source of good pictures and description for this fully underground VERY LIGHT house is in the MMM, in the article "M is for Mole" here: http://www.moonsociety.org/publications/mmm_classics/mmmc1_Jul2004.pdf, every "window" you see is actually a light/visual pipe and NOT a window as we normally think of them. Everyone who's visited the place commented that it was totally unlike any "earth-sheltered" {to use the PC version} they had ever visited) uses reflectors and mirror not only to bring in light but visual as well. You can use the same technique to bring enough light into an "under-Mars" greenhouse without the numerous drawbacks of an actual greenhouse.

Paul451:  I think you really put your finger on the kind of 'romantic' mindset I've been dealing with in this thread, every argument I put forward gets deflected with some 'patch' to save the greenhouse idea.  It's to the point of not even arguing that greenhouses are 'simple' proponents are telling me they MUST have them so they can enjoy the view of Mars AND plants at the same time (viewing them separately just isn't ascetically pleasing enough!).

While I agree in general (I'm arguing the same thing after all :) ) let us recall that a "romantic" mindset is in fact a job requirement for colonization :) I'm getting short-tempered myself over this issue so I'm going to try and self monitor but I am one to readily admit "I" have this problem with Venus and have to keep myself in control.

The continuous "patching" issue IS rather obvious but its a general issue with the self image of people living in space, be it on Mars or anywhere else. The basis is the idea of living off-the-Earth, ON Earth and the whole self-sufficiency, independent soul paradigm that is the heart (and soul) of the colonization "itch" itself. People "want" the idea of raising kids and crops under the open sky and gentle winds of (fill in the blank but the topic area is) Mars because they had an idealized conception of it being that way on Earth. Well it WAS that way, sort of, with a lot of squinting and such but that's EARTH and isn't really applicable to anywhere else in the solar system with very good reason.

You CAN in fact "do" a greenhouse on Mars, it will however be neither easy, cheap or efficient for growing food crops. And efficiency, not "daydreams" is going to be the way things are done.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 04/30/2015 09:36 PM
(Last part first)
I do not claim to know the truth, I give suggestions. Romanticism led to the nation states of Europe and the collapse of oppressive empires, I have no problem with romantic notions so long we can ground them in reality. After all, exploring is a very romantic notion.

Uhm, the "romantic notions" had to have hard-nose, practical application applied to arrive at that outcome. "Romantic" is always a good basis for a start but it HAS to give way to practical application which is the hardest thing to do.

Quote
Insects have been mentioned before, twice. I counter proposed that we grow and eat snails, as we do on August 29th every year (decapitation of John the Baptist).

(Insert Ketchup joke here :) )

Insects actually DO have higher conversion than any practical "meat" animal but only about 1/2 of the worlds population eat them on a 'regular' basis and the 1/2 that doesn't is the most likely to be colonizing Mars. On the other hand, protein is protein and HOW you get it is less and less applicable the more you can process it into other forms.

Quote
I also proposed going for spirulina or chlorella as the first crop on Mars.

You'd be surprised how difficult it is to get that idea to 'fly' in general conversations on space colonization :) I blame it on a hold-over from the afore mentioned L5 Society attitude but really they would be the MOST efficient crops to grow if you can convert them into edible (and more importantly acceptable) foodstuffs.

Quote
For the 5th time in this thread I will repeat that the Martian Greenhouse will require its own life support system, separate from the one of the habitat and this is the main reason I propose we keep the facility separate from the living facility. If you prefer I will use the term ECLSS, to repeat myself we most definitely need a separate ECLSS for the plant food growing facility which is to be separate from the human habitation facility. Since we are keeping these two systems separate we might as well have the plant food growth facility as a greenhouse on the surface and take advantage of solar illumination rather than provide all illumination artificially.

I figured from the tones I was seeing this has been brought up before but answer me one question then? Why? Why have a separate ECLSS for plants and humans when the very basis of long-term ECLSS is to integrate the two to the benefit of both? Having separate systems means you have to double or triple up on all power, maintenance, and construction and you lose a great deal of depth and robustness from an integrated system. If the "greenhouse" has to have its own, separate life support system then it becomes an additional burden rather than an additional resource so on what grounds can it be justified for use? And this is all so you can grow "food" in a greenhouse which in and of itself makes little sense. So, again, why?

Quote
By definition a greenhouse contains a heat source even if it is digesting manure, if it does contain a heat source it is not a greenhouse but a covered cold growth chamber.

Actually the definition is useless as on Mars you HAVE to heat inhabited areas because the outside environment is a cold sink. There are "greenhouses" in Antarctica that use natural sunlight but must also provide supplemental heating to avoid the plants dying. They have to use artificial lighting as well due to the length of darkness in the area. By your definition we have already established that a fully covered, artificially lit growing area on Mars is therefore a "greenhouse" and yet you seem to reject that definition :)

Quote
There is an index on how much area of farmland is necessary to feed one person for each country. The US is on top of the list because of its meat rich diet, but there are several countries on the list that manage to produce enough food for a healthy population with less land per person than the US. Since earth shipments will be finite and space under life support is also finite it is best to minimize the area necessary to grow food. The earth analogy on the back of my head are the monks of Mt Athos: the monks try to minimize food imported from outside the Mountain since they have to pay for it, they do not grow animals because their care can come at times they have set aside for prayers (though they do keep pets), they eat fish mostly during feasts and thus eat a mostly vegan diet. Yes not only are they not undernourished (unless they spend too much time doing the Jesus prayer to show up for the meal), several are actually overweight. We can grow sufficient and nutritious food based mostly on plants. As I have said several pages ago several times we do not know what a Mars diet will look like but plants plus tillapia or snails or insects if you prefer can provide it. We can get calories from oleoginous plants, vitamins and minerals from fruits and vegetables which have been bred to be low calories, there are several varieties out there for vegetable that do have higher calories than their cousins you buy at the supermarket. The food that you buy at the supermarket has been selected to meet market demand and can change as it changes: Up to the 1960's pork was the main source of fat, when demand arrived for lean pork in the 1960's we changed to races grown that had only 1/10th the fat of what was sold before. The same is true for fruits and veggies and let me tell you, the old varieties have not died down, they are still kept in the seed and variety collections. We can get proteins from beans or spirulina, starches from tubers etc. First though we need to know what diet we want, what can best survive the growing environment and provide maximum nutrients per volume. I certainly remember from horticulture class (as I mentioned a few pages before) that vegetables provide more nutrients per area which is why I have been talking about them.

"Farmland" will not exist on Mars for a long time if it ever really does. Soil farming is simply not efficient enough to use anywhere where you have to "construct" your growing environment. The cited examples,(being on Earth) all have what you will not have on Mars; Free air, water, and soil and mostly free nutrients. On Mars you're going to get the last one for "free" from humans and other inhabitants but you have to construct and maintain all three of the others and doing so just so you can grow plants in the "soil" is a non-starter. The cost is far to high.

Soil on Mars has to be chemically stabilized and sterilized (oddly enough human feces being mixed with it will actually partially neutralize both) and then cleaned and "built" into viable soil in the manner of soil remediation. (Either using local resources or as suggested by JohnForano using imported soil as a "starter") After that it will require continuous inputs and maintenance as per Earth soil to provide optimum growth. If any of the "-ponic" methods are used "soil" is not needed in any case yields are significantly higher with less labor.
The main question again becomes "why" a greenhouse over simpler and more efficient methods?

R7: No hard details handy on leakage rates but the higher the pressure difference the higher the leakage rate per length of seal. Submarine and space engineering "rule-of-thumb" has been stated in various places that "seals=leak" so have as few, and as short as possible. (Layering helps slow the rate but windows still leak)

In most work I've seen the concept is that the "main" growing areas (specifically on Mars but often anywhere in "space" since the environment must so fully be controlled) will have a higher average of Co2 than the main habitats but one thing I notice is ignored under these assumptions it the "indoor" air quality of the main habitat and the difficulty and doubled work loading of having "separated" systems as suggested. Fully integrated systems is something that seems to be extensively studied only within the last 20 years and the results look very good.

My credentials are an very high interest in the subject of space colonization of all stripes and a love of the RESULTS of gardening/food production but a extreme dislike of the actual labor involved, hence a very general knowledge of specific growing methods and subjects.
Hence the assertion that "-ponics" has a far higher production rate but here on Earth the economics are mostly marginal due to the "free" resources you don't have in space.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/01/2015 12:10 AM
The reason we need a separate ECLSS system on the Mars plant growth facility is SAFETY. Photosynthesizing plants consume CO2 at such prodigious rates that O2 concentration gets to dangerous levels fast. On an Earth greenhouse on a spring day mature plants will consume the CO2 in the air within a couple of hours from sunrise, this is why we open windows. People simply do not produce enough CO2 through breathing for all the O2 plants consume while photosynthesizing: Even if we digested completely all the carbohydrates in the food we ate and we do not (e.g. plant fiber) we do not consume 100% of the plants, there are always stalks and roots. While the MIT study on MarsOne run into a bug with CROPSIM and hence there will not be oxygen toxicity when the plants enter the flowering stage (as mentioned a few pages ago) it is a very real issue: We need to pump CO2 all the time for the greenhouse and if we allow the O2 to accumulate we can get to dangerous levels pretty fast. We either need to reduce the fraction of food grown on Mars as a portion of food consumed to level the CO2 we perspire or we need to keep greenhouse air separate from living air. Eventually we can recover CO2 from burning/composting the non edible parts but the rate of release of CO2 during decomposition is very different from the rate of plant CO2 uptake. We might also want to use the non edible parts of the plant elsewhere rather than just burn/decompose it. I am open to other suggestions that allow the growth of sufficient food and safety for humans, but I am under the impression that optimizing two living environments is better and we can use the greenhouse air to mine for gas resources: pull O2 out using and oxygen concentrator for other uses, allow N2 and Ar concentration to rise and distill both for other uses (fertilizer, ion engine fuel), stuff we ought to not do with breathing air which we can keep at Earth surface. This is not my area of expertise and I open to suggestions.

Hydroponics is also called soil-less, in that we grow without using natural soil. We can use just a pure liquid solution trough a properly sized table, we can spray the nutrients directly to the root which is hanging in mid air (in that case it is called aeroponics) or we can use an artificial substrate. Since this is an area of my expertise I suggest we use Martian soil/regolith (Martian soil does not qualify as soil for earth purposes hence it would still be hydroponics) which will most likely include the micronutrients necessary for plant growth. We talk about N,P,K fertilization but in reality plants need some 18 elements to survive. N, P and K are simply needed in the largest quantities. If we are to use a system without a substrate whether aeroponics or liquid nutrients we need to ensure that all elements are found in the solution. Also as any Cypriot hydroponics expert can tell you, when you are irrigating with bad quality water (Cypriot fresh water is very saline and very hard) there is a strong possibility that there will be ion interactions in the liquid solution leading to the formation of precipitates, that can clog the emitters. We do not know the quality of the water we will use on Mars for plant growth but the rule of the thumb is that good water goes for drinking, bad water goes for irrigation. Hydroponics has the advantage of better nutrient use efficiency, faster growing cycles but the disadvantages on higher energy and capital costs and the need to change the substrate. We will need to throw out the plant growth medium every 3 to 10 years, depending on what we use.

The use of higher CO2 concentration is called carbon fertilization and is used commercially in the Netherlands, Israel and other such places with tons of capital and few land. It is known to shorten the growing cycle and use less water (due to reduced stomatal resistance). The typical source of CO2 on earth greenhouses is to burn natural gas which produces purer CO2 without the unburned hydrocarbons of petroleum products or coal. I see no reason why not to use it on Mars, using Martian atmosphere as our CO2 source. While higher plants have a CO2 toxicity at around 3% depending on species, blue green algae can go as high as 80 or 100% CO2 for some species (spirulina is around 40% if I remember correctly). We could just pump and pressurize Martian air in the greenhouse as is, set the plant growth lines (using gas masks, firemen style rather than EVA suits) and see us get both food and O2, though we need to pump out the O2 for fire hazard purposes. Since there are people here in this forum dealing with ECLSS, try to out this scenario as an option when evaluating. The Greek people warmed to spirulina when ESA actually asked French chefs rated with several Michelin stars to create spirulina based plates. Another thing that spirulina has it going for it is that it is lenten, and people will eat food that they normally do not eat the rest of the year during lent.

My romantic idea is not a person alone taming the wild, kids on the range. My idea is far more collective, it is the shepherds coming down from the mountains, every Friday and Saturday night into town, wearing their Armani suits and driving their SUV so as to sing and dance with everyone in the nightclub. After all society is like the dancefloor, each one or people in small groups do their own thing but in the end we all dance together to the same song. Each one on his own but also all together. The first Mars colonists will be supported by an army of specialists on Earth. The 4 people on Mars are like those dancing on the VIP table, they are also part of the group dancing in the club, just less accessible due to their location.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 05/01/2015 06:16 AM
@AegeanBlue

I just love your contributions. You are explaining running greenhouses on earth, describing the problems and their solution. While the solutions need to be different on Mars, the problems to be solved remain similar.

I would like to see a closed loop ecology with as little exchange with the outside as possible. But that closed loop will need to be well controlled. Unlikely it will find a balance and work without control unless it becomes vast in volume and mass.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/01/2015 06:18 AM
I think we need to define a bit better what we mean by ECLSS, when NASA uses that term they mean the WHOLE process of keeping people alive.  But with regard to growing areas for plants and habitats being incompatible they are really only incompatable in the aspects of AIR HANDLING, which is a narrower (though obvius dominent portion of) ECLSS.

I imagine that we have more of an air-circulation LOOP that sends air from the habitat into the growing space and back again.  This isn't really 'duplication' of ECLSS, it's more along the lines of a multi-stage and multi-zone air handling.  In a normal space-craft intakes take stale air and send it into an air-scrubber which produces human-comfort-optimized air which flows out of air returns to circulate in the spacecraft.

We want to do something a bit more complex, the human habitat air is picked up by an intake, processed to being optimal for plants and is sent into the growing area.  Then the 'stale' air of the growing area is collected and again processed to be optimal for humans and is sent back into the human habitat.  A continual loop which maintains two dissimilar 'optimum' mixtures of air.

Human respiration will do several things, remove O2 from the air while adding CO2, H2O, trace contaminants and heat.  For human comfort air should be at around 50% humidity, 'room temperature' (which is a huge range of temperatures preferred by people in different climates) and <2% CO2 to avoid heavy breathing and <5% to avoid dangerous toxicity.  Finally no more then 33% Oxygen to avoid excessive flammability.

Plant photosynthesis will do some things inverse to this such as removing CO2 and adding O2, but other things like add trace contaminants and MASSIVE amounts of H2O which are similar.  Also the lighting system will likely add a LOT of heat too.  Plants can tolerate >90% humidity (but fungus will grow rapidly under these conditions), and they have a higher optimum temperature then most people find comfortable.

So what needs to happen in the habitat->growing space processor is that we scrub the contaminants and add any supplemental CO2.  On the reverse side we must dehumidify and cool the air heavily, as well as again remove trace contaminants.  Excessive O2 may also need to be removed.  So the air-handling needs are fairly lopsided onto heavily processing air coming out of the growing area.

If we remove excessive O2 mechanically then we would logically do that post growing area, but if we are employing some biological means such as decomposition (mushroom growing on cellulose was mentioned earlier) or even things like live animals such as goats which are ruminants.  Then these could essentially respirate the excessive carbon fixation of the plants and keep O2 levels in balance.  This section (which I will call the 'barnyard' would make a 3 part cycle of habitat->barnyard->growing space, but no air processing would need to happen between the habitat and barnyard, it's just a good idea to stay upwind of goats.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/01/2015 01:19 PM
Earth's atmosphere is only about 3% carbon dioxide, thus greenhouses on earth consume the air inside them a high rate.  This will not be a problem on Mars as it's atmosphere is mostly carbon dioxide, so any shortfall can easily be brought in from outside.  Also humans and food animals can produce CO2 thus they need to live together. 

Some people are also overly concerned about radiation.  It has been suggested in long transit times in space using about a foot of water around the living area to contain the cosmic radiation.  Thus the suggestion I had of having water stored above living and working areas, not only for radiation protection, but for gravity fed water system. 

Also, my son is in aquaculture, and he has shown me, and it is all over the internet with survivalists, that growing tilapia with a 12x12 greenhouse can not only supply protein but vegetables for a family of four.  This is not a lot of space.  Yes Mars has less sunlight than earth, but a 12'x12' greenhouse supplemented with some lighting, and a fish tank that is 4'x6'x8' to supply fish, and the fish supply fertilizer for the greenhouse plants.  Plants can be grown in a fine gravel and not soil.  This is like hydroponics, but this gravel media can support the plants like soil does.  The fish waste is washed over the soil to provide fertilizer and once completely cleaned returns to the fish tank aerated.  Tilapia also are plant eaters, with the young eating algae and probably the fastest growing food fish out there.  Less than 3-4 months to maturity.  Algae can also be processed into protein pellets to feed the tilapia. 

Food must be palatable to humans, otherwise that can cause problems.  Comfort food is also a necessity.  People can't be put underground for long periods of time, otherwise it can cause mental and emotional problems.  Greenhouse can provide both a vast panorama, even a small 12'x12' greenhouse, of the Martian landscape as well as plants to provide food and oxygen and comfort food such as various fruits and berries. 

Greenhouses will be small at first only providing vegetables, fruits, and berries, and coupled with fish tanks, protein.  As the colony grows, grains will eventually have to be grown, thus taking more space and some type of growing system.  A greenhouse can provide a cupola for nighttime observation of the Martian sky, or a small one can be completely covered by a retractable cover in just a couple of minutes.  I see multiple greenhouses like this above the water storage which is above the living areas.  Living areas could be semi-underground. 
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 05/01/2015 04:46 PM
AegeanBlue; The main issue here is with your insistence that the growing area will be a 'greenhouse' which is won't for many reasons we've gone over here (again) and neither will it be "separate" from the humans life support system. It is in fact part OF that life support system as humans are a part of the plants. It will also not be large and monolithic as there is no reason for it to be so and a lot of stated reasons for it NOT to be so.

It may be that you don't realize it but NASA and the ESA both have done their homework here and actually put people and plants in SEALED environments and extensively studied the results. The people lived the plants thrived and they kept each other alive and healthy with almost no outside input except power.

I appreciate your expertise in commercial greenhouse/hydro/aeroponics operations and maintenance here on Earth, (and frankly I need to get you to explain how things work to a bunch of folks over at the Seasteading Institute and on the internet in general who can't get past the idea of "soil" farming being the ONLY way to grow food :) ) but most of your concerns are based on issue with Earth operations that are not present or seriously mitigated in space due to the more artificial nature of the overall environment.

Spacenut: Radiation over a long term stay on Mars is going to be a problem. There's no getting around it and the BEST solution is to lessen exposure both by spending less time exposed and reducing the amount as much as possible.

This is applicable to plants, people, animals and algae.

There's no good reason to put the plants 'under-glass' and expose them to the hazards nor invest the resources and effort to do so. Light tubes work and work well and concentration if needed can be done with non-tracking, stationary reflectors of various types. Buried under the regolith significantly reduces the thermal, radiation, and structural issues with habitation yet you can still have the majority of the "feeling" (natural light, views, etc) of being "outside".

The idea that people "can't be put underground" for long periods of time is a hold-over and very false image of living in something like a mine shaft with a bare bulb hanging from a wire and water dripping from the walls which is nothing like actually LIVING underground. People live on Earth "underground" with only occasional outside contact or support, (Coober Pedy is probably the best example, {http://en.wikipedia.org/wiki/Coober_Pedy} with some residence spending most of the year underground) without ill effect and in places like the Moon and Mars it will be mandatory not optional.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/01/2015 04:55 PM
I did like the idea of a prism window to the outside using mirrors, or skylight type units to pipe some outside light in.  Fill the air space with helium or such and it minimizes the cosmic rays.  Don't know if cosmic rays can be bent or not with mirrors.  There needs to be some UV lighting, as we produce vitamin D with sunlight.   
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 05/01/2015 05:37 PM
Earth's atmosphere is only about 3% carbon dioxide, thus greenhouses on earth consume the air inside them a high rate.  This will not be a problem on Mars as it's atmosphere is mostly carbon dioxide, so any shortfall can easily be brought in from outside.

And here we go again...

So we bring in outside air and mix it with what? If you simply keep adding Mars air, your oxygen levels build up to dangerous levels. If you want to use nitrogen/etc from the Martian atmosphere to concentrate for a buffer gas, you need a system to isolate the N2/etc from the O2. (Which is usually pretty energy intensive.) And even then, how to you exhaust the low-CO2, high-O2 gas when you bring in more Martian CO2, without also throwing away nitrogen you've carefully concentrated.

There are solutions... but do you realise how many unique, heavy, fragile, labour-intensive-to-maintain systems we're adding to this damn greenhouse?

RanulfC,
Re: Separate ECLSS.

Impaler covered this. The needs of high-productivity food production and the needs of humans are going to be different. You need a buffer between them. I suspect that future HSF-ECLSS will increasingly have a biological-processing component, but such systems will be optimised (as in the NASA experiments) for human comfort. They will not provide sufficient protein and calories, and if designed to provide sufficient protein and calories, will not be balanced with human needs.

Having a single all-in-one box sounds like you're simplifying the problem, when in reality you've multiplied the difficulty exponentially.

"Two things" is often much much simpler than "one thing".
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 05/01/2015 05:43 PM
I did like the idea of a prism window to the outside using mirrors, or skylight type units to pipe some outside light in.  Fill the air space with helium or such and it minimizes the cosmic rays.  Don't know if cosmic rays can be bent or not with mirrors.  There needs to be some UV lighting, as we produce vitamin D with sunlight.   

Cosmic rays, (most high energy radiation) don't "bend" much at all which is why you avoid straight lines as much as possible. Argon gas (if you can get it) is a much better insulating gas than helium and easier to contain as well. UV can be reflected with the right reflector or we can use UV lighting since we've got everything from UV headlights to flashlights these days :)

Randy
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/01/2015 06:03 PM
Ranulf, could you please point me to papers on studies with people and plants in closed environment beyond Biosphere II? The Biosphere II paper Impaler shared mentioned a Soviet experiment where they would however bring food in rather than grow locally. Coming from one of the densest populated cities in the world, I need at times to be with many people and I need at times to go to the coast and watch the sea and its islands.

I would be very willing to show up and explain people things I know :) . The easier way though would be to give these people to read a book on Greenhouses and Hydroponics, there are several good ones out there.

Also, CO2 concentration in the atmosphere right now is at 400 ppm or 0.04%, not 3%. Plants are in simplified terms water pumps, we will need a dehumidifier in the plant growth facility in any case. Humidity control is choosing what pest you want to be attacked by: High humidity means fungus, lower can mean bacteria, aphids (and thus viruses), nematodes etc. Unlike people where bacteria and viruses are the main causes of disease, for plants it is fungi, which is why we keep humidity possible. Also there are several pests that thrive in greenhouses and rarely outside one. If for nutrition and growing conditions of plants on Mars we have good ballpark figures, for the plant pathology we are completely in the dark. Considering that the greenhouse I was in Portugal ended crops early due to excessive diseases, it is a lacuna that needs filling and will not be filled until we get to Mars.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/01/2015 06:38 PM
Pests will certainly be an issue and we should expect to ACCIDENTALLY bring along some Earth pests with us no matter how stringently we attempt to screen them out.

The smaller and more microscopic the pest the more likely it is to slip though, fungus seems completely inevitable, the human body will be a carrier and I suspect even the dried seeds that are brought will harbor them.  The fact that many plants have symbiotic relations with fungi is also an issue, an attempt to remove ALL fungi may be counter productive.  The existence of separate growing compartments would seem to be of only minor help in containing pathogenic fungi, bacteria or viruses as air will transmit all of these and any person/gardener moving between growing areas will be a vector.

Higher and larger pests like nematodes and out right insects are conceivably easier to prevent from ever getting to Mars, and to contain an 'outbreak' to one isolated growing area and if necessary purge it and wipe out the pest.

Based on what AG has said about humidity and pest problems it sound like we would want a low humidity growing areas that suppress fungus and they would be well isolated with some kind of double-door or air-curtain which would keep insects from escaping.  Periodically (perhaps as infrequently as once every few years) the growing area would be completely purged of plants (perhaps even dropping oxygen levels or using an extreme temperature) to try to wipe out any pathogens before re-planting, preferably in a different type of crop.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 05/01/2015 06:42 PM
Martian pest control thread (http://forum.nasaspaceflight.com/index.php?topic=30453.0)
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/01/2015 07:14 PM
What do folks think of the use of fiber-optics to carry light into the living or growing space?  As solid materials it would never present a pathway for GCR, it would be simpler to install then large hollow 'periscope' like tubes.  And within the human habitat it would be very easy to distribute the light evenly by snaking the fiber-optic cable across the ceiling without even using a fixture.

For the growing area I'm not sure if fiber-optics can effectively carry enough light to reach the high intensity necessary to get good yield.  As most of our fiber-optic technology is used to maximize data transmission rather then maximize total energy transmitted.  If it proves possible then the light collecting area outside could be VERY large, something like a linear-Fresnel lens based solar power-plant with fiber-optic cables take the place of the steam-pipes.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/01/2015 07:27 PM
I don't think CO2 is going to be a problem to produce with humans, and maybe small animals.  Earths CO2 is only about 3% of our atmosphere.  I think if anything there will be too much CO2 and we will need more plants/algae to absorb the excess CO2. 
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 05/01/2015 07:31 PM
What do folks think of the use of fiber-optics to carry light into the living or growing space?  As solid materials it would never present a pathway for GCR, it would be simpler to install then large hollow 'periscope' like tubes.  And within the human habitat it would be very easy to distribute the light evenly by snaking the fiber-optic cable across the ceiling without even using a fixture.

For the growing area I'm not sure if fiber-optics can effectively carry enough light to reach the high intensity necessary to get good yield.  As most of our fiber-optic technology is used to maximize data transmission rather then maximize total energy transmitted.  If it proves possible then the light collecting area outside could be VERY large, something like a linear-Fresnel lens based solar power-plant with fiber-optic cables take the place of the steam-pipes.

Fiber optic lighting might work. Large quantities of fiber would be needed to carry enough light. That would be a lot of mass to bring from Earth, making it expensive. LEDs run off of solar power probably would be more efficient.

It is worth looking at. Especially if low quality fiber optics made locally would be good enough for lighting.

http://www.thefoa.org/tech/lighting/lighting.html (http://www.thefoa.org/tech/lighting/lighting.html)
Title: Re: Scaling Agriculture on Mars
Post by: nadreck on 05/01/2015 08:25 PM
I don't think CO2 is going to be a problem to produce with humans, and maybe small animals.  Earths CO2 is only about 3% of our atmosphere.  I think if anything there will be too much CO2 and we will need more plants/algae to absorb the excess CO2.

NO NO NO 0.03% (300ppmv http://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere (http://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere))  :-[  EDIT 0.03% not 0.3% my bad math and as well it was pointed out to me that it was closer to 0.04% by Paul451 as well, thanks Paul!

Each specific instalation/base/community will need both redundant environmental management and a complex system providing different environments to different segments (optimize what is grown in a specific segment with mix and pressure changes) since growth rates will impact both atmospheric gas and chemicals disolved and suspended in the various water systems, production of the food and other resources from aqua/agri/animal cultivation will be driven by needs + margin requirements while chemicals removed and stored/dumped or chemicals added need to be separated/introduced in the system. This will be complex but is in principle just engineering to make it flexible/scalable/repairable.  The first few years at the first few bases will have the most rudimentary systems, scaling to, hopefully in the long run for connected communities of hundreds or more with lots of agri/aqua space but also one or more small park environments.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/01/2015 08:52 PM
I don't think CO2 is going to be a problem to produce with humans, and maybe small animals.  Earths CO2 is only about 3% of our atmosphere.  I think if anything there will be too much CO2 and we will need more plants/algae to absorb the excess CO2.

This is erroneous (and frankly embarrassing so), see AG's correction earlier.  According to https://www.hydrofarm.com/resources/articles/co2_enrichment.php  plants will have maximum growth between 1000 and 1500 PPM, and experience CO2 toxicity at 2000 PPM, which is a lower level then human begin to suffer even mild dizziness which is around 5000.  So it is actually our plants which set the upper bound on CO2, the ISS initially operated at 5000 PPM but engineers have been trying to bring this down to around 3000, which is still too high for plants. 

Most indoor environments occupied by people already reach or exceed the CO2 levels necessary to maximize plant growth.  A greenhouse has to add CO2 because it's got no animals inside, but it looks that just taking the air as is out of the human habitat will likely have all the CO2 needed.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 05/01/2015 09:14 PM
NO NO NO 0.3% (300ppmv)

0.03%.

300ppm = 0.3ppk = 0.03ppc

(And it's above 380ppm, so rounding to 0.04% as AegeanBlue said.)
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 05/01/2015 10:33 PM
What do folks think of the use of fiber-optics to carry light into the living or growing space?
Just my concern from earlier, that you cannot concentrate it when lighting is diffuse such as during a dust storm. On earth I think it is usually augmented with other lighting. This other lighting can be carried along the same fibre optic cables.

I think that even on the surface, fibre optic (and LED) lighting has some advantages over direct lighting if space is limited, in that you can light stacked trays of vegetables evenly.

I have a kneejerk reaction against solar cells and LEDs, but in the short term the cost would be pretty inconsequential compared to the cost of getting there, and in the long term they will probably get so cheap we will use solar cells for roading and LED monitors for wallpaper. Im trying to get over it.

--

There does seem to be a question mark over whether the surface radiation danger is linear. You would still have to run for shelter during solar storms I assume. Would solar storms hurt the plants?
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/01/2015 10:44 PM
Solar storms should be reasonably well blocked by the thin Martian atmosphere, it takes very little mass to block that kind of radiation.  We really only really need to be concerned about Cosmic Rays.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/01/2015 11:23 PM
CO2 toxicity depends on the specific species. Lower plants such as algae do better than higher plants with high CO2 concentration, which is why there are several attempts to use algae to sequester flue gases coming out of power plants. The seed industry has had a huge success keeping its multiplication material clean, so the seeds or little plants coming out of the envelope will be free of diseases. Possible sources for pests are the unsterilized parts of the habitat that arrive from earth and the Martian biosphere, which I am under the impression based on what the rovers are showing is that it does exist and due to the constant exchange of material between Earth and Mars is probably related in some way. On earth the main source for contaminants tends to be human and animal travelers, things like uncleaned shoes and ship ballast water. Over the last few decades there have been many experiments that humans and animals require a microbiota to survive. On Mars we might just discover that this is true of plants.
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 05/02/2015 04:18 AM
A grow facility, or greenhouse, is part of the overall life support system, even if atmosphere there is kept at different conditions from human habitation.

Considering allegations of dangerous levels of O2 production:
Presuming the plants in you grow facility can deplete 400ppm in 2 hours, and CO2 is replaced as it is consumed, that gives 50 hours to produce 1% more O2 partial pressure.  Hardly a big issue.  Human O2 consumption will hardly keep up with production from plants sufficient to feed them.  Which is why you agricultural systems use composting or equivalent to convert excess O2 and waste biomass.

Regarding humidity:
Dehumidification amounts to blowing air past a heat exchanger at the proper dew point for the desired absolute humidity.  Given heat input from lighting and otherwise good insulation some kind of cooling is needed anyway.

Crops with high yield with little space or labor requirement will of course be favored, all else being equal.  But enough volume within total life support to buffer a few days worth of O2/CO2 conversion is also desired for system simplicity and robustness.  If the system can operate without gas separators, high pressure pumps, etc, that leaves less to break down.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/04/2015 02:06 PM
Seems as if in a completely closed system, that the atmosphere could be constantly monitored.  Oxygen will be made for lox rocket fuel, and made by plants.  If it is too low a percentage, some lox could be allowed to boil off and enger the atmosphere.  If CO2 Levels are too low, some could be pumped and filtered in from outside, while removing excess O2.  This equipment will be operational in order to make lox fuel as well as methane.  A little could be tapped as the inside atmosphere is being monitored, say hourly.  At some point the right balance of plants to humans and animals will be met with very little adjustments. 

Another note, argon is about 3% of Mars atmosphere, so it can be filtered out for use as propellant for SEP propulsion and launched with a returning rocket to refuel SEP tugs bringing cargo to Mars, so they can make return trip to earth.  I see them carrying most of the non perishable cargo and equipment robotically on a continuous basis.  Maybe even being used in human cyclers from L2 to high Mars orbit and back to L2 thus smaller rockets could bring cargo an argon from earth to refuel and send off these cyclers. 
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 05/04/2015 05:19 PM
Ranulf, could you please point me to papers on studies with people and plants in closed environment beyond Biosphere II? The Biosphere II paper Impaler shared mentioned a Soviet experiment where they would however bring food in rather than grow locally. Coming from one of the densest populated cities in the world, I need at times to be with many people and I need at times to go to the coast and watch the sea and its islands.

Biosphere-II is about the worst example of how to set up a closed environment, which will probably go down as its biggest "success" in proving how NOT to set things up.

ESA, NASA, most government space agencies in fact along with numerous worldwide universities and private efforts have been experimenting, documenting, and discussing various "Closed-Loop Life Support" and support systems since the 1960s. Efforts tend to get a lot less "press" because they are smaller scale and more focused than something like Biosphere-II. For good reason. An internet search on the terms "CLLSS", (Closed Life Support System) "ECLSS", (Environmental Control and Life Support System) "Biological Hybrid Life Support", "Advanced Life Support Systems", will point out a number of studies, reports and descriptions of experiments done.

RanulfC,
Re: Separate ECLSS.

Impaler covered this. The needs of high-productivity food production and the needs of humans are going to be different. You need a buffer between them. I suspect that future HSF-ECLSS will increasingly have a biological-processing component, but such systems will be optimised (as in the NASA experiments) for human comfort. They will not provide sufficient protein and calories, and if designed to provide sufficient protein and calories, will not be balanced with human needs.

Having a single all-in-one box sounds like you're simplifying the problem, when in reality you've multiplied the difficulty exponentially.

"Two things" is often much much simpler than "one thing".

They are different but have been shown to be not THAT much different as to require a fully separate system. I'm not attempting to over simplify the problems, nor am I suggesting growing food crops in the corridors of the habitats :) You can run high intensity agriculture with life support and humans but you have to carefully and constantly monitor the interface and having multiple "modules" and not something monolithic is a HUGE factor in making the process' easier and simpler.

Impaler: Fiber optics are possible but I'm not sure if they would be cheaper/easier for a primary source than light tubes. Much has been written about using them as distributors for light in homes (and habitats) from a central light source be it artificial or natural. From what I've read most times for natural light they require a concentrator even on Earth which means they would probably need more complex systems on Mars.

Building a tube of mars-crete and vacuum deposit mirrors just seems simpler and easier to me.

Also note the thin Martian atmosphere blocks out none of the cosmic and very little of the solar radiation as its TOO thin and the lack of magnetic field means a vulnerability to things like CMEs.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 05/04/2015 06:11 PM
If CO2 Levels are too low, some could be pumped and filtered in from outside, while removing excess O2.

However, separating O2 from N2 is a complex energy hungry process. (Well, it's a simple process, but the equipment is complex.)

And you'll need extremely good carbon monoxide filtering. CO levels in the Martian atmosphere are well above toxic levels if concentrated to 1atm (about 22 times toxic levels), and that ignores any continuous build up from bringing in outside air.

The point is that this is not about putting up a greenhouse and just doing X,Y,Z... "Just bleed off the excess O2 for rocket fuel, just bleed off the argon for ion-drives, just add some CO2 from the atmosphere, just use the Nitrogen from the atmosphere..." Instead of making things easier, each of those steps is adding more and more equipment, unique and fragile, and more labour to maintain. And all of it needs to be designed to work on Mars with potentially 2 years between parts deliveries. And all of it needs to be delivered to the surface somehow (meaning it must be extremely light, and therefore even less reliable.)

This moves it further and further away from the sort of thing the first base or even the first settlement will be capable of doing.

[BTW, your oxygen maker for rocket fuel might not be compatible with separating N2/O2 from the greenhouse air. You will probably filter out CO2 from the atmosphere (fairly easy), so that you can feed pure CO2 into the O2-maker. The O2-maker therefore won't be capable of separating N2 from the O2.]

RandulfC/Impaler,
Re: Fibre-optic light channels.
I have to agree with Randy, a fresnel collector and some mirrors to pump light down a tube (with a simple dog-leg to block particle-radiation) seems vastly easier and lighter than using glass fibres, even if you could manufacture optically pure glass on Mars.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 05/04/2015 06:45 PM
Anything concentrating sunlight will stop working under dust storm conditions. Enough light is still there but scattered. So a directly lighted greenouse will work. Flat solar panels will work. Not sun tracking solar panels and not sun tracking light concentrators.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/04/2015 07:13 PM
If we are going to be a spacefaring people, we must figure out how to make a closed system work.  I know we can do the basics, water, oxygen, CO2, argon just from the Mar's atmosphere alone.  There may also be some trace nitrogen.  I do not know what the soil can give, but surely oxygen, iron, and maybe silicone.  I also know there is basalt in the surface rocks.  Nitrates may be in Mar's volcanic rocks. 

Some equipment can work automatically to make things, some might require excavation and extraction.  Plants will be needed to scrub the CO2 out of the air and provide oxygen.  Some animals will be needed for food, and to supplement the plants with fertilizers.  All waste, human or animal, will have to be recycled along with plant waste. 

All of this recycling equipment will need power and lots of it.  That is why I have recommended small nuclear power plants to supplement solar.  A lot of heat will be needed to smelt metals and basalt for useful products.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/04/2015 07:53 PM
Ranulf, I did look up Google scholar (graduate student's best friend) and the most relevant document I found was the attached paper. It is about the ESA MELISSA concept and they use a series of bioreactors to clean CO2 and human waste to food and oxygen, but it is more life support than full scale food growth concept. Also searches for ECLSS and Mars closed loop life support mostly lead to papers on waste recycling rather than the creation of an artificial ecology, which is what we are trying to do here in the end. There is also an article by Japanese researchers published by springer (Masamichi Yamashita, Hirofumi Hashimoto, Hidenori Wada, On-Site Resources Availability for Space Agriculture on Mars. Mars 2009, pp 517-542), which from a cursory look I gave talked a lot about potential food choices but insisted in a soil based agriculture system and did not address the CO2 problem (though it addressed sodium management). Biosphere II was a bad experiment, I agree. Have there been though experiments and studies on C mass balance in a Mars colonization scheme, as related to food, agriculture and breathing? I was not able to find that.

I am of the opinion that we need to optimize the greenhouse for plant maximum growth. We should keep CO2 concentration closer to 1000 ppm rather than 400 ppm, and gain weeks in the plant growing cycle. The practice for carbon fertilization is that usually around sunrise the greenhouse atmosphere is flooded with CO2 to 1000 ppm, they let the plants photosynthesize and in the afternoon workers open the doors and move in to do activities such as harvest. The idea is not that the atmosphere is toxic (it isn't), is that they do not want to lose the CO2 that they pumped in the morning and wait until it is photosynthesized to ambient levels. Now CO is not toxic to plants, rather they do eventually consume it after oxidizing it to CO2. There are several links on the web on what species make good houseplants cleaning indoor air from CO and other pollutants. I do not know about agricultural plants, this is not usually an issue on the field or in greenhouses.

Now decomposition of plant material can also be a source of food, and not just in a small closed loop MELISSA style. Composting was mentioned earlier as a source of CO2 for plants. Ionmars' talk about composting in his wonderful website "the Mars Pioneer" is so far the only discussion I have read at length. He proposes growing carbon rich plants to help composting, but that is not necessary. In reality for composting you need to control C/N ratio, humidity, temperature and material size. There are two related processes for decomposition, manure digestion and composting. For manure digestion the idea is to leave the animal manure at near room temperature with sufficient humidity until the exothermic reaction is over and its use is no longer a threat plants. Basic principle is that you do not fertilize with human manure, for sanitary reasons, it carries too many human disease vectors. The end result is a N rich (by organic standards) material than can be used as fertilizer, although the N/K ratio is screwed compared to what plants need, leading to the Chesapeake Bay water quality problem (I can explain more if you wish). For composting you can use human manure, you need to mix it with a carbon rich material so as to create a C/N 3:1 ratio and make sure that the composting pile has the sort of particle size that allows air to enter everywhere and not just the surface layer. The composting reaction is strongly exothermic and if not controlled can lead to a fire. Tomato stalk (partially dried) and more so hay coming cereals grown in the greenhouse can be used as the carbon rich material, earth manuals mention wood chips and the like because for your typical suburbanite it is easier to find wood chips that dried tomato stalk or hay. However there are better uses for hay, namely growing Pleurotus mushrooms.

During the field trip as an undergrad to Crete and Ierapetra specifically after the greenhouse we went to a Pleurotus mushroom growing facility. It was shaped like a greenhouse but it was covered instead with dark brown plastic that did not allow any light to enter, the light we had was the one entering from the open door. We were told that it was critical that the facility was in darkness, otherwise plants might sprout and we did not want that. Thus unlike the greenhouse which should be placed in the light, preferably (IMO) outside, the Pleurotus facility should be placed underground in the darkness. Inside the Ierapetra facility there were cubic bales of hay, circa 50 * 50 * 50 cm covered by plastic tarps, except for three rippings by a knife on each side except the one on the floor. The process was quite simple, at the start of the season the farmer bought the hay, covered it in tarps, ripped it and in the rips placed Pleurotus inoculum. The fungus over the year consumed the hay and produced the stem and body (the edible parts) which he would cut off when it reached commercial size. The idea was also not to allow the fungus to reach the spore stage, otherwise the body would wither and no longer be commerciable. Ierapetra climate is such that he did not need temperature control, but obviously that is not valid in Mars. Also after the fungus had consumed the hay, what was left inside the tarps can be sold as organic fertilizer, it is not waste.

Now if we use the stems, roots and hay from the greenhouse for Pleurotus rather than composting the human manure, the issue become what we do with it. I liked aquaponics, feed it to the fishes, as they've been doing in China for millenia or as they do at the estuary of the James river. The question though is, what is the minimum people/feces production for a viable aquaponics farm, in terms of volume, BOD5 or other relevant metrics? How many people would it require on Mars before we can have an aquaponics facility.

Another question is what do we do with the compost? It will be slow in coming and not voluminous. We can try to use it to create soil on Mars, but it will take time and soil has its issues (exhaustion, soil borne diseases etc). My idea is that we can put it in ceramic pots and use it to grow trees in the pots. A Mars arboretum will be constructed eventually, fruit trees are a very dense source of food, although they require more care than field crops (e.g. pruning). Since it does take years to create a tree, we might as well have a head start, and offer some apples or oranges or olive oil to the colonists, even the little production that can come from small trees.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/04/2015 08:26 PM
From what I read aquaponics can be adapted small scale for a family fairly easily, 12'x12' greenhouse 4'x6' fish tank.  This may be enough for vegetables and fish for a family, but is it enough CO2 absorption and O2 production to sustain the family.  Now if the aquaponics extend beyond just vegetable production to wheat, rice, oats, barley, or corn production, maybe there will be enough CO2 to O2 conversion.  There will not be forests, but maybe indoor house type plants for aesthetics and oxygen production along with the food plants if there is room initially. 

What we learn on Mars, could also be applied to very large diameter space cities rotating to produce artificial gravity. 
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/04/2015 09:01 PM
That's the third time you have tried to give us that same aquaponics set up, stop, we heard you the first time and no one believes this set up your describing could possibly yield all the food needed to feed 4 people.  8 x 2000 cal = 33 million J, over 12 hours that is a rate of 800 watts, or ~80 watts per m^2, full Earth sunlight is ~1000 watt/m^2 so you would need to have a conversion of 8% to make that work, real plants have a fraction of a percent conversion rate of sunlight into food energy.

If your wondering how many plants are needed to supply Oxygen vs how many are needed to provide food, the rough ratio is that you need 10x more to be feed then you need to breath.  That's why Mars One has excessive Oxygen and most biological life-support system don't try to feed people.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/04/2015 10:05 PM
Tilipia grow from egg to 2 lb fish in about 3 months, eating algae and plants later.  I will try to find a link.  I grow enough veggies in a 12' x 12' space for my wife and I already.  Now, I live in the south, so I can grow veggies year round.  In winter I can grow collards, turnips, carrots, beats, rutabegas.  Summer I can grow 3-4 tomato plants, green beans (so many I give them away or freeze them, cucumbers, pole butterbeans and peas.  Or I can grow some corn or okra.  Anyways it doesn't take much space for vegetables intensive gardening year round.  Tilipia can be grown in a large tank, but they cannot live below 40 degrees F.  Therein is my problem, unless I put time in a greenhouse to heat in winter.  Various herbs and spices can be grown indoors in little flower boxes or pots. 

The only thing requiring a lot more space is grains. 

Now you will have different vegetables at different times of the year, but I fed my large family of 9 with a backyard garden of about 50'x100' with enough vegetables for year round.

I didn't even try very hard and worked a full time job.  Now, my wife worked hard during the harvest season to can and freeze things. 

My son is majoring in aquaponics, and he tells me with the right set up, a lot of tilapia can be grown in a small space.  20-30 years ago, you didn't hear about tilapia.  Now they are being grown commercially here in tanks or ponds.  You find it frozen mostly at supermarkets.  Not very expensive.  Catfish are also being grown commercially, but they take longer to grow to maturity.  Either way, more protein can be grown in a small space with tilapia than any land animal.  Side benefit is their waste is used in experimental closed systems to feed the plants, thus water returning from the plant feedings is cleaned to return to the tank.  I will try to "Google" this tonight.  Auburn University near my home is doing a lot of this research. 
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/05/2015 12:20 AM
Here are some sources of aquaponics:

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

http://www.friendlyaquaponics.com/

Do a google search, and read some results.  Results are phenomenal.  This is probably the future of agriculture, especially with countries with very large populations like China, India, etc.  A lot of food can be grown in small spaces with the right equipment and set up. 
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/05/2015 03:37 AM
spacenut:  How many times do we have to point out to you that vegetables constitute a tiny portion of the typical Americans diet because they are so low in caloric density.

Are you seriously trying to tell us you have no grocery bills?  That you don't also buy meat, bread, dairy, oils, sugars and other high density foodstuffs.  Have you tried to do even the most basic caloric math on how much your garden is yielding and how much your eating?

My own family garden is roughly the same size (all be it on very poor soil that is still being improved) and we spend $400 - $500 a month on groceries between 2 people.  Eventually the garden will cover all our vegetable needs but that's a fraction of total calories and until you realize the huge gulf between vegetables and actually feeding a family your not adding anything of value to the discussion.

Also, 9?!?
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/05/2015 12:45 PM
I am type II diabetic, I eat very little if any white carbohydrates.  Yes, I buy food.  Far less than you for two. However, I do hunt also.  One or two deer a year provides my hamburger.  My grandfather once raised chickens and I lived with my grandparents in the summers.  10-20 chickens provided them with all the eggs they could use and they gave eggs to my parents and other family members.  They had fried chicken a lot, as well as chicken soups and baked chickens.  They also fished a lot.  That is off topic.  However, I have some Mormon friends, and they store a lot of dehydrated and freeze dried foods.  They said you can't live off that forever, it gets old.  Any one foodstuff will get old real fast.  Variety is good as well.  All these so called low calorie vegetables have a lot of vitamins.  They too are needed.  If Mars is going to be self sufficient, the more high vitamin vegetables as well as high calorie are needed.  Protein will also be needed.  There is no such thing as a purely vegetarian.  They must eat eggs or fish, or take vitamin supplements.  Aquaponics is the best way to get a lot of food in a small area.  Oh, beans and peas can produce a lot of plant protein as well as carbohydrates in a small area.  I am allergic to soy and peanuts, but these do not take a lot of area to produce for a few people.  Soy can be made into synthetic meat. 

There are about 6 billion people in the world.  When you consider the amount of space used per person for agriculture it really isn't much since most agriculture is one season.  If you grow year round in the same space, that can multiply by 2 or 3.  Then if you use lighting at night it can double that.  Plants grown in greenhouses that have night lighting cut growing time almost in half. 

Same with chicken farms.  Layers lay an egg in the morning.  Then they turn on lights at about midnight, for a couple of hours and the chickens lay another egg.  Most of our eggs come from chickens that lay two eggs a day.  If they stop doing this, they are sent to slaughter.  Also, most American chickens only live in one cubic foot of space almost their entire life. 

The biggest problem with scaling Agriculture on Mars is grains.  Wheat, I know takes about an acre per family for a years supply of bread.  Don't know about corn or rice.  Then there is oats and sugarcane.  Rice and sugarcane will need more water.  If Mars is going to be self sufficient in food production, there will need to be a lot of room required for agriculture.  Unless there is some mineral, diamonds, gold, platinum, or other valuable items that can be traded back to earth for food.  However, I foresee small scale aquaponics to begin with, expanding later into small animal and agriculture until we invent replicators.  At some point even trees for paper products, cotton for clothing since there is probably no oil or coal on Mars for synthetic clothing.  Synthetic hydrocarbons could be made, but it will be energy intensive. 
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/05/2015 01:58 PM
Something else I have thought of.  Most vegetables, if you look on the seed packets, have a maturity of 90 days or so.  If that food was grown indoors, greenhouse, underground greenhouse with 24 hour lighting, that would be cut almost in half.  Then continue planting once harvested, and instead of one crop per season on land, you can end up with almost 8 in the same space.  So again I say, a lot of food can be grown in a small space, not just algae.  Algae can be fed to fish, fish provide humans with food and fertilizer for crops.  Humans will need bulk crops for our digestive system.  That is where vegetables come in.  Pills and supplements will not always work.  Plants cannot provide all the nutrients and protein that animals can, so at the very least, fish, chicken, and maybe rabbits or other small animals will eventually have to be incorporated into the food chain.  I get by with very little if any bread, rice, or potatoes since I am type II diabetic.  Meat and green vegetables are all you need to live if necessary.  Then again variety of foods will be a comfort to colonists so far from earth. 

Even small fruit trees can be grown indoors such as pear, apple, fig, lemon, tea, plum, and peach since they do not grow that large.  Maybe 10-12' at most.  I could see fruit trees being grown in large open common areas that connecting habitats are attached to, like the middle of a mall or large hotel complex.   

Like I said, food production will begin small and gradually expand as construction permits. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 05/05/2015 02:24 PM
Algae will be the most important staple IMO. They can provide feed for fish and chicken. They can provide cooking oil. They can provide starch that can replace grains for many (not all) purposes. Starch can be processed to sugar. So algae can provide a lot of the calories needed by humans without changing their eating habits. More if people do change their eating habits.

I would expect that calories from eggs, the chicken fed with algae, will come cheaper than calories from vegetables or staple crops.
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 05/05/2015 03:01 PM
Algae will be the most important staple IMO. They can provide feed for fish and chicken. They can provide cooking oil. They can provide starch that can replace grains for many (not all) purposes. Starch can be processed to sugar. So algae can provide a lot of the calories needed by humans without changing their eating habits. More if people do change their eating habits.

I would expect that calories from eggs, the chicken fed with algae, will come cheaper than calories from vegetables or staple crops.

I agree, but there will be some vegetables grown for variety. The waste from fish and chickens will make good fertilizer for growing vegetables and spices. Lettuce, tomatoes, peppers, etc. will be good for moral by giving Martian cooks more options and flavors.

One big problem with chickens are the feathers. It's a big waste product issue. Some researchers have made paper and plastic out of chicken feathers, but I guess on Earth that is not economically viable. However, on Mars they might be useful processes.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 05/05/2015 03:31 PM
I agree, but there will be some vegetables grown for variety. The waste from fish and chickens will make good fertilizer for growing vegetables and spices. Lettuce, tomatoes, peppers, etc. will be good for moral by giving Martian cooks more options and flavors.

Absolutely, including onions, garlic and all kinds of herbs.

Edit: I never intended to imply otherwise.

One big problem with chickens are the feathers. It's a big waste product issue. Some researchers have made paper and plastic out of chicken feathers, but I guess on Earth that is not economically viable. However, on Mars they might be useful processes.

Feathers are protein. Their nitrogen content adds to the quality of compost. Just shredder it to small pieces.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/05/2015 05:51 PM
Exxon did a study on algae.  Algae would be grown in greenhouse tubes.  Greenhouses that would cover about the size of Rhode Island could provide enough algae oil to eliminate traditional oil sources.  However, it costs about $4 a gallon for algae fuel, and that is without taxes.  So, as traditional oil is depleted, algae will eventually replace it.  It is a win-win.  The amount of CO2 algae removes from the atmosphere would be burned back into the atmosphere as transportation fuel.  Anyway, on Mars it would be the primary basic foodstuff.  Like someone said, made into pellets for fish and chickens, oils for cooking or for even making plastics. 
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 05/05/2015 09:25 PM
So, as traditional oil is depleted, algae will eventually replace it.  It is a win-win.

Totally offtopic but FYI.

Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/06/2015 12:32 AM
I know it is off topic, but I worked for a natural gas company as an engineer for 39 years.  We have a 92 year supply of natural gas if we didn't drill another well as of now.  This is because of fracking.  Now, as the third world grows and buys vehicles, their oil consumption will rise.  Also the need for plastics.  However, doom and gloomers aside about running out of fuel, we will not, probably ever at least in a few hundred years.  Not to say we need to go to algae production if anything, to make for a carbon neutral infrastructure.  Anything learned in algae production can be applied to Mars infrastructure.  I think algae should be grown for animal feed now, just to replace corn with less space.  If they mandated 10% algae oil vs ethanol, I think the land would have better use.  Using corn for ethanol instead of animal feed has driven up the cost of meat, especially corn fed beef.  Even algae pellets might be as good or better than corn for feeder cattle. 

I think NASA should get out of the launching business (SLS) an use the money for R&D for living in space or on Mars or even the moon.  Just contract out launch services for whatever they need in space.  Also, anything they contract out should be modular and able to launch on at least two different launch services to keep things competitive.  Mars things included.   
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/07/2015 12:49 AM
The main reason that vegetables are a small part of the American diet is not so much because they are low in calories (which they are) but because Americans eat a huge amount of meat. The first Mars colonists will eat a diet that is closer to what is being consumed in the Third World, it will take a long time to produce actual meat on Mars. In any case, as I mentioned before fruits and vegetables are low in calories because of selection, we have selected the highest yield varieties that produce the lowest calories. If we want calories from vegetables we can do that by selecting the appropriate varieties. A purely plant based diet is unhealthy for humans, in that you cannot get Vitamin B12, at a bare minimum you need mushrooms. What the diet on Mars will look like depends on the caloric needs of the Mars colonists and our ability to grow. Artificial illumination 24 hrs/day will not shorten the growth cycle, after all best fit variable for the phenological cycle is Growing Degree Days. Furthermore there is the issue of photoperiodism, in order for some species to enter the reproduction stage they need nights, otherwise all that you will have is vegetative growth. Supplementary illumination can be useful, but the best ways to improve yield in a limited space would be hydroponics and carbon fertilization.

Until approximately a century ago animals were fed exclusively with food that was unsuitable or left over from human consumption, such as hay. Mars animals, when they arrive, will be fed similarly. West Berlin after the airbridge would keep a supply of canned food including meat enough to feed the population for a year in case of another blockade. They would take out the meat cans and sell them to the population when they where close to their 10 year expiration rate. If it is long term preservation that we want, we can do it. In any case though it is best if we grow our food locally, no matter what it is and at first it will come out of a greenhouse because transportation from Earth will always be limited in weight and volume. Spare parts though will also be under the same limitation, which is why we must balance efficiency and yield with robustness and resilience. I am against the full artificial illumination solution due to robustness and resilience factors, two sources of radiation are better than one, especially in the very corrosive environment of the greenhouse. I have no romantic notions though of self sufficiency, as an agronomist I am fully aware of the long tail that my food consumption has. Numbers such as that 1 acre can bring the bread of a family for a year have behind them assumptions of how much bread is eaten by such family, what is the yield of wheat, what variety we use, how we fertilize, the growing method etc. We need to first set quantitatively the needs and the method before we can quantify food. Thankfully the world's space agencies have done that, though until we get closer to colonization they will only remain numbers to be debated
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 05/07/2015 04:26 AM
West Berlin after the airbridge would keep a supply of canned food including meat enough to feed the population for a year in case of another blockade. They would take out the meat cans and sell them to the population when they where close to their 10 year expiration rate.

OT I know. I loved those. I bought a lot of them. They were cheap when I needed cheap and I liked the taste. Of course very different to fresh meat. High caloric density food though and well storable. I think they will be part of the food brought in early from earth. Complemented with local vegetables from the beginning.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 05/07/2015 04:42 AM
Even in the 3rd world the primary source of calories is GRAIN, which should be obvious as these are the cheapest calories in any country or market.  3rd world diets are meat and protein poor, but this dose not make them vegetable rich, the calorie deficit is generally filled with more cheap grain not vegetables, this is why people are generally so malnourished and unhealthy in the 3rd world their diet is even worse then western diet.
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 05/07/2015 09:51 PM
Mushrooms were mentioned to provide essential proteins.  Sounds like a good use for waste biomass left over from growing other crops.  Small animals that eat parts of plants humans don't also make sense for the agricultural system.  Milking animals tend to be larger and eat more in relation to food produced, so wouldn't be in the mix early on.  But something like a yeast producing a dairy substitute would be nice to go with the occasional pizza night.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/08/2015 07:26 PM
Even in the 3rd world the primary source of calories is GRAIN, which should be obvious as these are the cheapest calories in any country or market.  3rd world diets are meat and protein poor, but this dose not make them vegetable rich, the calorie deficit is generally filled with more cheap grain not vegetables, this is why people are generally so malnourished and unhealthy in the 3rd world their diet is even worse then western diet.

Not quite true, in several developing countries tubers are the main source of food rather than grain. Potatoes are considered both vegetables and major crops. Taro and sweet potatoes are integral parts of many tropical and temperate diets. In Sub-Saharan Africa tubers are the main source of calories, rather than grain. This does not lead directly to malnutrition, the reasons are multifaceted. There is a study that 14th century Englishmen ate as many calories as today's English (not so sure about Scots or Welsh and Irish) but although their skeletons show fit people, more English are overweight. The reasons have to do with the origin of calories (in the Middle Ages it was beer rather than meat) and physical activity (farmer versus office worker). Is alcohol desirable as part of the Martian diet? What would be the source, beer, wine, distilled drinks? Wine is an integral part of Mediterranean diets after all, for those whose faith allows them.

guckyfan: I have eaten those meat cans myself, I had an uncle who lived in West Berlin and I would visit him with my family. What surprised me was the blandness of the can, no branding nothing. I have no doubt we can conserve food for long, if we can conserve nutritious food is another issue ...
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 05/08/2015 11:35 PM
I don't see alcohol as a desirable part of the Martian diet.  But short of prohibition with wide support it is hard to avoid.

Related to that, I expect little tolerance of intoxication in locations where it can lead to a more general threat to the colony.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/09/2015 04:02 AM
The consumption of alcohol has been part of most human societies. The reasons for this practice did not have to do so much with intended intoxication as much as water safety: There is a quote by the Prussian king Friedrich the Great that this newfangled coffee thing is dangerous and that the German people should keep on drinking beer which has nurtured them for generations. There has always been a ritualistic element in alcohol consumption, whether we are talking about Holy Communion or the dance floor of the night club. Perhaps I am biased because I am South European that idea of drinking is not to get drunk, drunkenness has always been looked down. Alcohol is the traditional disinfectant of water, whether we are talking about the strongly diluted wine that the Homeric heroes would drink every night or the beer that Frederick the Great mentioned, because before water treatment plants plain water brought dysentery. That being said I think that Mars colonists should not purposely attempt to ferment alcohol, except perhaps for rocket fuel.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 05/18/2015 12:17 AM
As automation and robotics are increasingly incorporated into agricultural production here on Earth, could some of these technologies be useful for Mars?

https://www.youtube.com/watch?v=tU7Jq2Ilp0Y
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/18/2015 12:38 AM
I am type II diabetic.  I can eat all the meat I want along with mostly green vegetables, salads, and fruits.  I can get by without bread, rice, or even potatoes.  By doing this I can get by without any medicine.  Now, meat is the biggest problem in a small space, except for fish in tanks.  However, fish along with chickens, and maybe some small animals are doable, by feeding them algae pellets which can also be grown in a small space. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/18/2015 05:30 AM
As automation and robotics are increasingly incorporated into agricultural production here on Earth, could some of these technologies be useful for Mars?

https://www.youtube.com/watch?v=tU7Jq2Ilp0Y

The right answer is both yes and no. Since this is a forum of rocket scientists think of the automations at the Mercury/Gemini/Apollo capsule and the automations at Orion/Dragon V2/CST-100: modern capsules can do things the old ones could not, but not everything that people can do. First of all the environment inside a greenhouse is highly corrosive far more than the field where many automations are pioneered. Also robots as still good for some things but not for others. We can make a great algorithm, machine vision etc and be able to make a robot harvest heads of lettuce coming out of the substrate properly. However trying to find in a cucumber or tomato plant where the fruits actually are, if they are ripe for harvest, if there is a disease taking place etc. etc is far more difficult. Easy automations like controlling the pH of the nutrient solution or measuring the weight of the water in the substrate, directly and indirectly, so as to time irrigation will probably be adopted. On Earth we are seeing capital replace labor, which is leading to automations. On Mars there is another issue: limited Mars. Do we want to bring a single purpose 50 kg robot rather than give a few hours of extra responsibilities to the agricultural specialist? How robust is the robot and can we manufacture spare parts? Could these 50 kg be used to bring something better? We will most definitely have agricultural production before we have industrial production, though I am sure we will be able to build parts.

On another note, the current version of All About Space (the one with the Hubble cover) has a two page article on Mars agriculture. 1 and 3/4 of the page is a drawing of a preliminary Mars surface colony with a greenhouse. The last 1/4 page is mostly an interview with a University of Florida professor of Space Agriculture, where he talks how he is trying to make plants grow at 1/10th earth surface pressure so as to make the greenhouse lighter and easier to transport from earth. Personally, I am under the impression that people could not survive at 1/10 surface pressure even in a 100% O2 atmosphere and would require a pressure suit, which is self defeating.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/18/2015 12:01 PM
I don't foresee plants or a greenhouse being transported from earth.  I see seeds, which will be planted on Mars after the greenhouses are built to grow the plants.  Corrosion is from the fertilizers used in a greenhouse.  That is easily solved using a lot of plastic components, as well as aluminum and stainless where metals are needed, and they can be plastic coated.  Most vegetables humans eat are small.  Only the grains are larger.  Then there are vine crops such as grapes.  Small fruit trees and bushes shouldn't be hard either.  Nut trees are large and they will probably have to be transported from earth for several years.  Agriculture will have to be attended to on a daily basis, but not impossible.  There should be no insect problem.  Fish and small animals will have to be butchered by hand and the waste dehydrated and processed for fertilizer or fish or small animal or chicken feed. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 05/18/2015 12:25 PM
10% earth sea level pressure should be well survivable with pure oxygen and some accimatization. That would be similar to partial oxygen pressure at 5,5km altitude. 15 to 20% would be easier to handle though.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/18/2015 01:48 PM
On transporting a greenhouse from earth the tradeoff is this: Do we transport the infrastructure to construct the greenhouse, even though the use will be limited outside the greenhouse (how many windows do we need?) or do we transport one greenhouse, large enough to feed all the colonists at maximum growth? This is what needs to be decided. Corrosion in a greenhouse is an issue of high temperature and humidity, not just fertilizers but yes, it is solvable. It simply requires a ruggedness we do not need on Earth, where if all else fails you can simply buy and install a spare part.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/18/2015 02:10 PM
Mars is cold and dry, so a greenhouse is not really going to be as big a problem as on earth.  And like someone said, most of the plants will be grown underground with piped in sun and artificial lighting.  Humidity can be managed with dehumidifiers.  Also the water produced by dehumidifiers is sterile so it can become the potable water source.  Dirty fish water is pumped over the plants to feed them, and after filtering through the soil, the clean water goes back to the fish tanks.  The heat generated by greenhouses on earth is from trapped sunlight, which might not be the case on Mars. where heat will be needed due to the cold environment.  Also LED lighting is cooler than incandescent lighting and uses less electricity.  Any excess heat can be used to heat the living and working areas or radiated outside. Through water tanks above the living areas. 

I think the best way to do a Mars environment on earth as a test bed is probably Greenland since it is nearby. 

I also don't think Mars is going to be that hard.  Everything can be engineered.  Also, food production should be twice what they need, just for redundancy.  Excess can be frozen, dehydrated, or canned in case there is an equipment problem or some disease makes it's way to Mars.  I also think there should be multiple greenhouses growing different foods in case one is lost due to a meteorite or rocket crash.  Each living and greenhouse area connected by pressure chambers like on a ship so areas can be sealed off if there is an emergency. 
Title: Re: Scaling Agriculture on Mars
Post by: Optimist on 05/18/2015 05:23 PM
Just read this, should be good for Mars.

From the article:

"A small piece of muscle you can produce 10,000 kilos of meat."

http://nextbigfuture.com/2015/05/lab-grown-meat-thirty-thousand-times.html

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/18/2015 07:11 PM
Food and agricultural products in general are not produced continually assembly line style, biology works in growth spurts. Even algae (which I think would be the best first crop) will produce in cycles. As a result just to keep the people there you need to produce twice what you need in order to cover shortfalls and spoilage. For lab grown meat, it requires a very rich nutrient solution just to survive, currently it is a very inefficient method to produce food. It would be better to feed the colonists the broth used to grow the meat rather than the meat itself. As for LED lights, I do not want to repeat myself but so far, there is little experience with use of LEDs in greenhouses on Earth. We are still several decades from the first greenhouse on Mars, we can be patient and just draw the broader picture
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/18/2015 07:49 PM
On another note: most first colony concepts I have seen, both for Mars and for the Moon, assume that first colony would be made of stuff mostly sent from Earth and left on the surface. It will take quite some time before the underground structures get build. I am under the impression that while the first colonization mission will include a bulldozer/earth moving equipment, it will take time before under or above ground structures are built. I see the first greenhouse being a light structure brought from earth on the surface. The question is of course (and we have spent 10 pages arguing about it) on what follows next, more of the same with supplementary illumination added or turn the whole settlement into Mole town, completely independent of the environment with everything artificial lighting. Considering how surprisingly compacted proved the ground on the Phoenix landing site, let's wait and see where and how we are supposed to build anything.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 05/18/2015 09:40 PM
Some plants can be grown in regular lighting, house plants for instance.  Even some herbs and spices are grown indoors in little pots.  LED will probably be the lighting of choice due to low electrical use.  Some plants might require a UV light.  Like someone said sunlight can be piped in via prisms or skylight.  It could possibly be intensified with reflectors and mirrors on the surface to improve indoor growing.  Say two reflectors aiming to the same location could make it more earthlike in intensity. 

Also, living units can be put on the ground and earth pushed up on the sides/and or over the top.  It doesn't have to be underground completely.  Just enough for protection.  Earth, plastic, and water can filter a lot of radiation without having to be multi meters thick.  If you are going to berm around a landing pad, living areas can be on the back side of the berms, or in the berms themselves. 

Another thing I though about is mining ice.  If a glacier or ice is several kilometers away from the landing living are, recharging stations can be along the way to the ice using electric trucks. 
Title: Re: Scaling Agriculture on Mars
Post by: Optimist on 05/19/2015 08:06 AM
Quote
For lab grown meat, it requires a very rich nutrient solution just to survive, currently it is a very inefficient method to produce food. It would be better to feed the colonists the broth used to grow the meat rather than the meat itself.

@AegeanBlue

Posted about lab grown meat, cause the topic is "scaling" Agriculture on Mars .
I have no doubt about your great knowledge about agriculture, and I think u are right, that at the start of the colony it would be better to just drink the broth used to grow the meat, rather than the meat itself.
However as the colony grows, I am sure most would appreciate a meal, that tastes and looks like a meal, and you have to chew down, rather than drink it.

Btw, great thread everybody.





Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 05/19/2015 09:17 PM
If you read Jared Diamond's Gun Germs and Steel, you will see that advances in human civilization is associated with more efficient ways to grow food and exploit natural resources in general. The typical way to exploit plant resources that were not directly edible by people was through domesticated animals. The first food animals we will have will eat resources not directly edible by people, such as metabolism products (think tillapia in aquaponics) or leftover stalks from the plants. Is it worth it to create a nutrient broth for artificial meat or to grow the animal and slaughter it? What is the infrastructure that required for the one or the other option and what is its other utility? Being an agronomist I am more in favor of growing the entire animal, because that was what I was taught in class. What I am comfortable with is not necessarily what is the best solution in our case. In any case our answer will be depended on the technological advances as we get closer to mounting the colonization mission.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 05/20/2015 04:57 PM
If you read Jared Diamond's Gun Germs and Steel, you will see that advances in human civilization is associated with more efficient ways to grow food and exploit natural resources in general. The typical way to exploit plant resources that were not directly edible by people was through domesticated animals. The first food animals we will have will eat resources not directly edible by people, such as metabolism products (think tillapia in aquaponics) or leftover stalks from the plants. Is it worth it to create a nutrient broth for artificial meat or to grow the animal and slaughter it? What is the infrastructure that required for the one or the other option and what is its other utility? Being an agronomist I am more in favor of growing the entire animal, because that was what I was taught in class. What I am comfortable with is not necessarily what is the best solution in our case. In any case our answer will be depended on the technological advances as we get closer to mounting the colonization mission.

Growing the whole animal is energy and space intensive, even if we assume high intensity, close spaced conditions (which aren't all that healthy for humans or animals really) and the waste and issue with slaughtering and processing are to be avoided if at all possible :) (Born and raised in cattle country here and am FAR too well aware of what entails in getting a "good" steak :) )

Randy
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 06/08/2015 04:17 AM
This popped up today on spacetoday.net

http://www.thestar.com/news/insight/2015/06/06/can-red-thumbs-grow-food-on-mars.html

It is a general audience article more than anything scientific but it did raise an issue I had not thought of: metal toxicity in the soil. Another issue I did think of but have not mentioned before is that if we go with farming in actual Mars soil rather than hydroponics or pot, we would need to heat the first 50 cm at least of the soil, in addition to the greenhouse, otherwise we have no place to grow roots and irrigation water will be frozen.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 06/08/2015 06:58 AM
This popped up today on spacetoday.net

http://www.thestar.com/news/insight/2015/06/06/can-red-thumbs-grow-food-on-mars.html

It is a general audience article more than anything scientific but it did raise an issue I had not thought of: metal toxicity in the soil. Another issue I did think of but have not mentioned before is that if we go with farming in actual Mars soil rather than hydroponics or pot, we would need to heat the first 50 cm at least of the soil, in addition to the greenhouse, otherwise we have no place to grow roots and irrigation water will be frozen.

I once had a large fishtank in my home. So reading a lot about that I came to hear about chelates. They are complex organic compounds neutralizing metal ions, in fish tanks specifically copper ions which is highly toxic to many organisms.

http://scifun.chem.wisc.edu/chemweek/chelates/chelates.html

So biology will take care of metal ions as long as they are not too high concentration.

If a greenhouse is something with the greenhouse effect and keeps the incoming energy from the sun inside cooling can easily become a larger problem than heating. The soil below will heat up, not immediately but over time.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 06/08/2015 08:20 AM
if we go with farming in actual Mars soil rather than hydroponics or pot

As has been mentioned before, you won't be planting directly into the Martian "soil". Air-pressure will lift the greenhouse off of its foundations unless it is fixed to 1 tonne of anchor mass per square metre of roof area. (So a simple 10m wide linear greenhouse would need five tonnes of anchor mass each side per metre of greenhouse length.)

Five tonnes of rock is around 2-3 cubic metres. So you need to set piers several metres down into bedrock in order to hold the structure down. To keep the air from leaking through the regolith, you need to seal the sides down to a similar depth. Essentially the "Martian soil" that you are planting into is effectively artificial fill for the top 2-3 metres. It'll be as warm as you want to make it.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 06/08/2015 08:34 AM
As has been mentioned before, you won't be planting directly into the Martian "soil". Air-pressure will lift the greenhouse off of its foundations unless it is fixed to 1 tonne of anchor mass per square metre of roof area. (So a simple 10m wide linear greenhouse would need five tonnes of anchor mass each side per metre of greenhouse length.)

Five tonnes of rock is around 2-3 cubic metres. So you need to set piers several metres down into bedrock in order to hold the structure down. To keep the air from leaking through the regolith, you need to seal the sides down to a similar depth. Essentially the "Martian soil" that you are planting into is effectively artificial fill for the top 2-3 metres. It'll be as warm as you want to make it.

That is why I believe pressure vessels which self contain those forces are better than anything anchored in the ground. And why much smaller diameters but more of them are very likely more efficient.

Also one of the main reasons why growing algae is so efficient. They would grow in transparent hoses or pipes that can be very thin skinned and easily contain a pressure of 10 psi.
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 06/20/2015 09:08 PM
Some plants can be grown in regular lighting, house plants for instance.  Even some herbs and spices are grown indoors in little pots.

Whatever the method chosen on grounds of efficiency etc for the bulk of food production, some food will be grown in crew quarters and work spaces for morale purposes.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 06/22/2015 04:35 PM
It is known since the 18th century that sleeping in the same room with plants can be dangerous. I see plants though in the lighted corridors of the habitat.

Now, on heavy metals, plants are selective absorbers and thus very likely will reduce the metal content on the edible part, or at least we can select varieties that do so. The issue is that we are in a very closed system, the metals sequestered in the hay may simply appear in the food chain when we use the hay to grow mushrooms. They can get concentrated in the compost, making it unsuitable for plant growth, leading to higher input of carbon dioxide rather than reuse. Non edible plants in the corridors can be a solution, but we will have psychological rather than food benefits.
Title: Re: Scaling Agriculture on Mars
Post by: kch on 06/22/2015 04:49 PM
It is known since the 18th century that sleeping in the same room with plants can be dangerous.

Some more than others ...

https://en.wikipedia.org/wiki/Little_Shop_of_Horrors_(film) (https://en.wikipedia.org/wiki/Little_Shop_of_Horrors_(film))

;)
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 06/25/2015 04:32 AM
It is known since the 18th century that sleeping in the same room with plants can be dangerous. I see plants though in the lighted corridors of the habitat.

That's a myth. Consider two scenarios: 1) You sleep in a dark room with a plant in it; 2) You invite a fellow colonist to your room and after some crew bonding and healthy exercise you both sleep in the room. Question: Which scenario will absorb more oxygen and emit more carbon dioxide? (You'll obviously get more methane emitted with the latter!)

Although by 'crew quarters' I was thinking of all the places the crew inhabit when not working, even with bedrooms the atmospheric effect of the odd plant will be small. Far less than the differences produced by the different masses of individual crew members.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 06/25/2015 04:43 AM
Under normal circumstances I would refer to the writings of the Encyclopedists and others from the Age of Enlightenment referring to the danger of sleeping with plants because they respire at night, but my college textbooks are an ocean away from my house. The issue depends on the size and activity of the plant that you share the room with, if we are talking about a small cactus, no problem. If we are talking about a greenhouse, don't do that. I only see seeds of agricultural plants flown to Mars, so while I do see basil or parsley grown in pots, I doubt we would see pretty flowers
Title: Re: Scaling Agriculture on Mars
Post by: kch on 06/25/2015 07:12 AM
It is known since the 18th century that sleeping in the same room with plants can be dangerous.

Some more than others ...

https://en.wikipedia.org/wiki/Little_Shop_of_Horrors_(film) (https://en.wikipedia.org/wiki/Little_Shop_of_Horrors_(film))

;)

... on the other hand, there is a possible benefit from a well-fed plant -- improved vision.  It's a widely-known principle -- "feed me, see more" ... ;D
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 07/11/2015 06:50 AM
Found this article. Insects are going mainstream on earth. They can do it on Mars.

http://www.ft.com/intl/cms/s/0/b72f9ebe-0f5c-11e5-b968-00144feabdc0.html?ftcamp=traffic/partner/US/CNNMoney/widget/auddev#axzz3fGmP4Vlw

With algae and plant waste as feedstock it should be affordable produce.
Title: Re: Scaling Agriculture on Mars
Post by: R7 on 07/11/2015 08:58 AM
Found this article. Insects are going mainstream on earth. They can do it on Mars.

http://www.ft.com/intl/cms/s/0/b72f9ebe-0f5c-11e5-b968-00144feabdc0.html?ftcamp=traffic/partner/US/CNNMoney/widget/auddev#axzz3fGmP4Vlw

With algae and plant waste as feedstock it should be affordable produce.

Quote
But 1lb of food-grade cricket flour, made from about 5,000 crickets, retails at about $30-$40, which clearly limits its appeal.

Hunger. $30 burning in the pocket. A pound of ground crickets or beef tenderloin? Decisions, decisions...

How can the bug food be that expensive?? Bugs should have better feed conversion ratio than bigger animals.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 07/11/2015 09:45 AM
Hunger. $30 burning in the pocket. A pound of ground crickets or beef tenderloin? Decisions, decisions...

How can the bug food be that expensive?? Bugs should have better feed conversion ratio than bigger animals.

Seems the article is behind a paywall now. It was not when I first read it and not when I posted the link.

The reason is in that artcle too. So far it was done on a very small scale. The example was that people pay easily some  money for 10 crickets to feed their lizard. So very small businesses could make good money on it. Prices will go down when it is done on a much larger scale for human consumption.

Also people are willing to pay a premium for products like quorn which could easily be a cheap protein source for the poor -  if the poor would eat it.
Title: Re: Scaling Agriculture on Mars
Post by: Ludus on 08/11/2015 06:47 AM
http://aerofarms.com/why/technology/ (http://aerofarms.com/why/technology/)

I'd think Agriculture would be based around standardized systems something like this. The independence of a settlement would be based on how much of the system could be produced locally and how much had to be imported. I doubt it will be worth trying to farm in soil using natural sunlight. By the time anybody is actually on Mars, this sort of system may be working on a pretty large scale on earth. These systems are a lot more productive per unit of air volume, water, labor, nutrients, all of which will be in short supply. They would work fine underground in lava tubes. They don't involve guessing games or experiments with Martian soil or light conditions, they could be expected to pretty much work out of the box since they control all the environmental conditions (except for Gravity which could be tested with tethered modules in space).
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 08/11/2015 07:15 AM
That may or may not be a suitable system for Mars.

However:
Quote
a totally controlled growing environment without sun or soil and minimizing harmful transportation miles.

sounds ridiculous. Saving cheap low cost, low energy transport and using electric lighting. ::)
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 08/12/2015 12:53 AM
That may or may not be a suitable system for Mars.

However:
Quote
a totally controlled growing environment without sun or soil and minimizing harmful transportation miles.

sounds ridiculous. Saving cheap low cost, low energy transport and using electric lighting. ::)

Your must be talking about transport on Earth (as that statement is absurd with regard to Mars).  But transport on Earth is not remotely low energy, it's based on burning petroleum and lettuce is low density so transport costs are certainly significant part of it's cost, it is for any agricultural commodity transported significant distances.

Their is a very viable business model here (particularly as California the source of most of the nations lettuce goes up in flames), the cost of electricity to grow a plant indoors is not remotely as high as you seem to think it is, I grow Tomato seedlings for the garden each year for nearly a month and they have an electricity cost per plant of around 50 cents.

For Mars the proposed system looks wonderfully low in mass and high in density, the use of aeroponics over hydroponics would greatly reduce the volume of water needed in the growing loop and thus reduce the amount of water needed to be collected on Mars.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 08/12/2015 01:10 AM
aeroponics along with aquaponics for fish and plants would both be good ideas.  Grains will have to be later as larger greenhouses would be needed.  However about one acre of wheat can provide all the bread for a family of 4 for a year.  Now that is one harvest season a year.  If you grow in a greenhouse controlled environment you might get 2-3 times as much per year, thus providing for 8-12 people from one acre.  Then you have corn and rice as the other two staples.  Rice will require more water, but that might be where aquaponics can come in.  In America 90% of corn at one time was for animal feed, until ethanol was mandated in gasoline.  This could or should be replaced with algae pellets. 

Algae can be grown for animal feed and one can get a lot more per acre of space, in plastic tubes in a greenhouse, than from a pond.  It could probably be processed with artificial flavorings for human consumption. 

Then you have another problem, especially with grains, storage after harvest.  Grains can be dehydrated and stored, but fresh food would either have to be canned or frozen. 
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 08/12/2015 01:35 AM
That may or may not be a suitable system for Mars.

However:
Quote
a totally controlled growing environment without sun or soil and minimizing harmful transportation miles.

sounds ridiculous. Saving cheap low cost, low energy transport and using electric lighting. ::)

Growing underground! Forgotten World War Two bomb shelter 100ft below tube tunnels becomes world's first subterranean farm. (http://www.dailymail.co.uk/news/article-3143564/Growing-underground-Forgotten-World-War-Two-bomb-shelter-100ft-tube-tunnels-world-s-subterranean-farm.html)
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 08/13/2015 08:59 PM
Growing underground! Forgotten World War Two bomb shelter 100ft below tube tunnels becomes world's first subterranean farm. (http://www.dailymail.co.uk/news/article-3143564/Growing-underground-Forgotten-World-War-Two-bomb-shelter-100ft-tube-tunnels-world-s-subterranean-farm.html)
Would that not require solar voltaic panels several times the area of the crops being grown?
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 08/14/2015 01:46 AM
Yes, but it would be film at much lower mass then creating a transparent greenhouse to collect light.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 08/14/2015 04:06 AM
Sunlight can also be brought in via periscopes.  LED lighting is also very low wattage. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 08/14/2015 05:37 AM
Sunlight can also be brought in via periscopes. 

I think not. That method requires concentration of light to get much light through a small opening. Concentrating light during duststorms does not work.

Non tracking non concentrating solar does work because more light is scattered than actually filtered out. Solar panels work with scattered light, concentrators do not.
Title: Re: Scaling Agriculture on Mars
Post by: Ludus on 08/15/2015 06:38 AM
Growing underground! Forgotten World War Two bomb shelter 100ft below tube tunnels becomes world's first subterranean farm. (http://www.dailymail.co.uk/news/article-3143564/Growing-underground-Forgotten-World-War-Two-bomb-shelter-100ft-tube-tunnels-world-s-subterranean-farm.html)
Would that not require solar voltaic panels several times the area of the crops being grown?

Or a reactor. PV like Sunlight and dirt farming might work out but there would be a lot of potential hazards with fragile surface deployments. In earth deserts it's a major job to clean dust/sand off the panels.

With LED farming under completely controlled conditions it's possible to get high multiples of yield per cubic foot of farm structure.

A colony core in a lava tube underground could be pretty secure with just a reactor for power and a consistent source of water. This kind of agriculture would make food a mostly predictable solved issue.
That sort of colony could afford to experiment with PV panels and sunlit agriculture with less risk of a critical failure.
Title: Re: Scaling Agriculture on Mars
Post by: Ludus on 08/15/2015 06:56 AM
Oops. I see that I'm off the OP topic in talking about initial core settlements.

I guess my response to scaling would be that it's most likely the same sort of manufacturing issue that scaling other parts of the settlement would be. Despite being possible, I don't think surface agriculture under simple inflated plastic enclosures is going to be secure enough under Martian conditions to be worth the work it would take.

There really is a scaling advantage to very controlled agriculture systems like this. You just have to solve the problems of replicating them and you can scale indefinitely. With more traditional agriculture that's less controlled you can't because variations in conditions intervene. Crops that work in one place fail in another. Harvests that are fine one season fail the next. The variability is the enemy of scaling. Mars has seasons and weather and variable soil/surface chemistry. Excluding all that variation is worth something.

Title: Re: Scaling Agriculture on Mars
Post by: Hog on 08/15/2015 11:27 AM
I just heard a stat that agricultural capacity will need to DOUBLE by 2050 from its current output in order to support the inhabitants of Earth.

Hopefully some of this agricultural research related to Mars or space travel in general, will have benefits for the rest of us here on Earth.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 08/15/2015 01:08 PM
Hopefully some of this agricultural research related to Mars or space travel in general, will have benefits for the rest of us here on Earth.

That may well be the case. I cannot imagine wheat or rice or corn production for staple food on Mars. Instead I think of algae to produce starch. Wheatflour, rye flour, rice flour, corn flour are just starch with a small amount of the right kinds of protein added. Grow bacteria or funghi GM-modified or just derived by breeding for the right proteins and you can produce bread, bake products, noodles. A wide variety of staple foods. Vastly more productive on Mars but probably also more productive on earth when done on a wide agricultural industrial scale instead of a scale for expensive novelty foods. It can be done in areas not suitable for conventional agriculture and with much less water.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 08/17/2015 04:19 AM
Aeroponics is technically a form of hydroponics, it is hydroponic cultivation wihtout a substrate. Its main advantage is that it allows ample space for root growth, otherwise it is more complex and prone to failure than using a substrate. Generally the environment of a greenhouse is higly corrosive, and the more equipement we put the more prone we are to creating points of failure. Hydroponics though (in all their forms) become a necessity because they are easier to isolate from the Mars environment and because transporting the entire fiendishly complex soil ecosystem is very hard, it is better to rely on machines that to hope that unknown microorganism X that was not transported was not so critical.

To create an underground tunnel you can either use a Tunnel Boring Machine or you dig and cover. As I have repeatedly stated in the previous pages I am not a friend of underground agriculture, I prefer sunlight which rises and falls without human intervention necessary and can be supplemented with artificial illumination and heating if necessary. Others have noted the pschological advanteges of being "out" rather than always living as molemen. Let's keep underground what is best done underground (e.g. pleurotus mushrooms) and keep on the surface what is done best on the surface. I believe that the first major farms on Mars will look like Ierapetra or Campo de Almeria on the surface with some underground facilities for mushrooms.

Increasing global food production is unrelated to growing food on Mars. Most 3rd world farmers can increase their yield by actually adding fertilizer. However very often their country lacks the infrastructure (roads, refrigerated trucks) to bring this extra food to the urban markets. As a result they have a perverse incentive not to increase agricultural yield of their crops. Increasing global average food yield is more a development problem than an agronomic problem
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 09/18/2015 04:57 PM
http://www.eater.com/2015/9/17/9338665/space-food-nasa-astronauts-mars

This is a more general article but I think it fits here better than at other threads
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 09/30/2015 05:40 AM
This article was published inspired by the water on Mars discovery:

http://motherboard.vice.com/read/nasa-now-we-can-build-greenhouses-on-the-red-planet
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/05/2015 04:02 AM
With the release of The Martian, several more articles on farming on Mars have been published in the popular press. I wouldn't be surprised if several more get also published this month. Now, articles which deal with real issues like soil composition or setting up hydroponics, I do not expect in the popular press.

http://www.tulsaworld.com/business/technology/tu-professors-looking-to-create-edible-algae-for-space-travel/article_c74eab25-9efd-5bc1-995d-fdb26c54bc46.html

http://techcrunch.com/2015/10/04/nasa-astronauts-can-already-farm-on-mars/
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/05/2015 04:43 AM
I had posted this already on the MCT and ECLSS thread but it fits better here.

There is the melissa advanced life support project of ESA. It includes anaerobic processes to break down waste, aerobic processes to make nutrients available for plants again and bacteria/algae and higher plants for food production.

http://ecls.esa.int/ecls/?p=melissa

(http://ecls.esa.int/ecls/images/newmelissaloop560.jpg)
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/05/2015 06:30 AM
I had posted this already on the MCT and ECLSS thread but it fits better here.

There is the melissa advanced life support project of ESA. It includes anaerobic processes to break down waste, aerobic processes to make nutrients available for plants again and bacteria/algae and higher plants for food production.

http://ecls.esa.int/ecls/?p=melissa

(http://ecls.esa.int/ecls/images/newmelissaloop560.jpg)

I think I have posted a paper about preliminary results from MELISSA and as I said MELISSA is more about turning waste products into something useful than for growing food. I will read the weblink you posted though to see if that has changed.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/05/2015 07:30 AM
I think I have posted a paper about preliminary results from MELISSA and as I said MELISSA is more about turning waste products into something useful than for growing food. I will read the weblink you posted though to see if that has changed.

Then I have probably read it and forgot.

I see it as a design for a fully closed life support system with food plants and humans in the loop. Naturally they would concentrate on the aspects that are not so well known in conventional agriculture. That's compartment I to III.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/07/2015 04:14 AM
Would it be possible to come up with some kind of liquid medium that could be useful for hydroponics while also being stable in the open Martian environment? Perhaps some liquid medium with a very low vapor pressure so that it would keep liquid form without evaporating - and yet the same liquid medium would also be suitable for aquaculture.

That way you could have large pools of it in the open Martian environment, and the plants would grow inside those pools.

We already know that some heavy brine solutions can exist in the open Martian environment. Would it be possible to grow plants in the right kind of heavy brine?


Or wait - what about plants that grow under the soil, like potatoes and other root plants?
Could it be possible to engineer a potato that grows significantly deep enough under the soil, so as to be more protected from exposure to the Martian surface environment?

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/07/2015 04:56 PM
Would it be possible to come up with some kind of liquid medium that could be useful for hydroponics while also being stable in the open Martian environment? Perhaps some liquid medium with a very low vapor pressure so that it would keep liquid form without evaporating - and yet the same liquid medium would also be suitable for aquaculture.

That way you could have large pools of it in the open Martian environment, and the plants would grow inside those pools.

We already know that some heavy brine solutions can exist in the open Martian environment. Would it be possible to grow plants in the right kind of heavy brine?

Plants have salinity limits on what water they can survive. The Permanent Wilting Point is defined as -15 bars, meaning that if water in the soil medium is unavailable at that pressure plants die. Now, if we have saline water, you need to remove the vapor pressure equivalent of salinity, so if the salinity is equivalent to 3 bars the plant will die if no water is available at -12 bars. Now PWP is defined conventionally at -15 bars for most plants, olive trees survive up to ~-18 bars and date palms, the most resilient plant know to -22. If we had plants that could survive at Mars brines which are more saline that ocean water on Earth, then Earth's oceans would be covered with forests...

Quote
Or wait - what about plants that grow under the soil, like potatoes and other root plants?
Could it be possible to engineer a potato that grows significantly deep enough under the soil, so as to be more protected from exposure to the Martian surface environment?


Photosynthetic plants need radiation to photosynthesize. Tubers will put their collecting tissue below ground, as opposed to fruit trees that have it above ground, but they still need an aboveground part exposed to the elements to collect radiation and complete the whole photosynthetic cycle. Several heterotrophic organisms do grow far below ground, but you can't expect and autotrophic organism where there is no radiation.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 10/07/2015 08:23 PM
(https://s-media-cache-ak0.pinimg.com/736x/43/cc/97/43cc972e2326d009cae636593d99174e.jpg) (https://s-media-cache-ak0.pinimg.com/736x/43/cc/97/43cc972e2326d009cae636593d99174e.jpg)
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/08/2015 06:40 AM
Plants have salinity limits on what water they can survive. The Permanent Wilting Point is defined as -15 bars, meaning that if water in the soil medium is unavailable at that pressure plants die. Now, if we have saline water, you need to remove the vapor pressure equivalent of salinity, so if the salinity is equivalent to 3 bars the plant will die if no water is available at -12 bars. Now PWP is defined conventionally at -15 bars for most plants, olive trees survive up to ~-18 bars and date palms, the most resilient plant know to -22. If we had plants that could survive at Mars brines which are more saline that ocean water on Earth, then Earth's oceans would be covered with forests...

Hmm, salinity isn't the only colligative means of depressing vapor pressure and elevating boiling point.
Maybe a combination of different solutes could sufficiently depress the vapor pressure and elevate the boiling point to make for a viable liquid medium for a suitably adapted plant/algae/whatever?

Quote
Photosynthetic plants need radiation to photosynthesize. Tubers will put their collecting tissue below ground, as opposed to fruit trees that have it above ground, but they still need an aboveground part exposed to the elements to collect radiation and complete the whole photosynthetic cycle. Several heterotrophic organisms do grow far below ground, but you can't expect and autotrophic organism where there is no radiation.

Hmm, it sounds like there needs to be a cross between a potato and a cactus. The cactus is able to withstand severe conditions aboveground, and that's where the radiation is.

Or does somebody else have any other ideas about what basic plants / features should be hybridized together to achieve a more Mars-tolerant species?
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/08/2015 06:58 AM
Hmm, it sounds like there needs to be a cross between a potato and a cactus. The cactus is able to withstand severe conditions aboveground, and that's where the radiation is.

Or does somebody else have any other ideas about what basic plants / features should be hybridized together to achieve a more Mars-tolerant species?

 :)

Actually I had thought about this in my more crazy moments. A completely genetically engineered cactus like plant - minus the spikes - that provides its own internal pressure through a thick skin. It would probably not be able to take in any nutrients from the outside so it would need to be dripfed by a pipe with all nutrients including CO2. It would also need a greenhouse cover to improve temperature but not pressurized.
Title: Re: Scaling Agriculture on Mars
Post by: A_M_Swallow on 10/08/2015 09:16 AM

Plants have salinity limits on what water they can survive. The Permanent Wilting Point is defined as -15 bars, meaning that if water in the soil medium is unavailable at that pressure plants die. Now, if we have saline water, you need to remove the vapor pressure equivalent of salinity, so if the salinity is equivalent to 3 bars the plant will die if no water is available at -12 bars. Now PWP is defined conventionally at -15 bars for most plants, olive trees survive up to ~-18 bars and date palms, the most resilient plant know to -22. If we had plants that could survive at Mars brines which are more saline that ocean water on Earth, then Earth's oceans would be covered with forests...

Kelp and seaweed grow in salt water. These are used as food plants.
https://en.wikipedia.org/wiki/Aquaculture_of_giant_kelp (https://en.wikipedia.org/wiki/Aquaculture_of_giant_kelp)

Sea plants are built for high pressure where as Mars has a low pressure atmosphere. Mountain plants are adapted for low pressure and temperature.
Title: Re: Scaling Agriculture on Mars
Post by: Impaler on 10/08/2015 09:42 AM
It seems some Canadian won a portion of the Innocentive challenge (along with 2 others) for proposing Chlorella algae as a food source.  As that is a very old idea and not remotely patent-able I assume he must have described an efficient device to grow it in and process it.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/08/2015 04:07 PM
Hmm, it sounds like there needs to be a cross between a potato and a cactus. The cactus is able to withstand severe conditions aboveground, and that's where the radiation is.

Or does somebody else have any other ideas about what basic plants / features should be hybridized together to achieve a more Mars-tolerant species?

 :)

Actually I had thought about this in my more crazy moments. A completely genetically engineered cactus like plant - minus the spikes - that provides its own internal pressure through a thick skin. It would probably not be able to take in any nutrients from the outside so it would need to be dripfed by a pipe with all nutrients including CO2. It would also need a greenhouse cover to improve temperature but not pressurized.

Well, what are the over-arching goals here? To me, the goal should be to come up with a "crop" plant that is as self-sustaining as possible in the natural Martian environment, requiring the least amount of support effort/infrastructure for it to flourish, while generating the greatest amount of nutritious biomass.

So if effort and infrastructure are measured in $, and nutritious biomass is measured in calories, then your metric is calories/$
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/08/2015 05:32 PM
Well, what are the over-arching goals here? To me, the goal should be to come up with a "crop" plant that is as self-sustaining as possible in the natural Martian environment, requiring the least amount of support effort/infrastructure for it to flourish, while generating the greatest amount of nutritious biomass.

So if effort and infrastructure are measured in $, and nutritious biomass is measured in calories, then your metric is calories/$

Yes and anything that could potentially grow on the surface will IMO not reach that goal. The temperatures are almost always too frigid to facilitate useful growth, they are barely enough for survival, not for meaningful production of biomass. That's why I believe whatever solution there will be the that greenhouse. It is cheap because it can consist of a very thin plastic foil, similar to what is done in Spain, but even much thinner foil because it does not have to stand up to severe weather. I am thinking 0,08mm.

My guess is the most productive will be algae circulating in transparent pipes or plastic hoses under a greenhouse roof. Those pipes don't need to be very thick. Just enough to contain a minimum of pressure like 150mbar or 3psi. Algae might be optimized for different nutrients by genetic manipulation or simple breeding. Probably oil and starch. Maybe one algae that produces both can be most efficient.
Title: Re: Scaling Agriculture on Mars
Post by: ThereIWas3 on 10/08/2015 06:46 PM
How about some fish that eat the algae?
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/08/2015 07:29 PM
Tilapia eat algae.  They produce fertilizer for traditional crops through aquaponics.  Algae can be dried and compressed into pellets to feed chickens.  Algae can be processed into various oils for oil based products and foods. 
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 10/08/2015 08:31 PM
Well, what are the over-arching goals here? To me, the goal should be to come up with a "crop" plant that is as self-sustaining as possible in the natural Martian environment, requiring the least amount of support effort/infrastructure for it to flourish, while generating the greatest amount of nutritious biomass.

However, the effort to engineer something incredibly exotic that can survive outside seems to waste the potential for engineered plants to be part of the internal ECLSS. And I would think, if we're broaching the idea of that level of bio-engineering, an engineered "all-in-one ECLSS plant" living inside your habitat would be an easier goal than "surviving below-freezing in an irradiated near-vacuum and growing fast enough to feed the settlers".

(Even just engineering a food plant that can tolerate high CO2 levels. So that you can simply pressurise atmospheric CO2 in a greenhouse. Lets you expand food production faster than trying to build systems that can stay within the finicky narrow CO2/O2/H2O/pressure limits required by natural plants.)
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 10/09/2015 05:53 PM
Plants have salinity limits on what water they can survive. The Permanent Wilting Point is defined as -15 bars, meaning that if water in the soil medium is unavailable at that pressure plants die. Now, if we have saline water, you need to remove the vapor pressure equivalent of salinity, so if the salinity is equivalent to 3 bars the plant will die if no water is available at -12 bars. Now PWP is defined conventionally at -15 bars for most plants, olive trees survive up to ~-18 bars and date palms, the most resilient plant know to -22. If we had plants that could survive at Mars brines which are more saline that ocean water on Earth, then Earth's oceans would be covered with forests...

1 bar = standard Earth atmosphere pressure.  Are you talking about how high plants can carry water by osmotic pressure?
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 10/09/2015 10:50 PM
1 bar = standard Earth atmosphere pressure.  Are you talking about how high plants can carry water by osmotic pressure?

https://en.wikipedia.org/wiki/Water_content (https://en.wikipedia.org/wiki/Water_content)

Looks like soil wetness is measured mechanically as how much water you get at different suction levels (negative hydraulic pressure), and given as a unitless fraction between 0 and 1. The harder you have to suck to get water, the drier the soil.

Water content at zero suction simply measures the amount of water draining from the soil. Low suction is used when measuring how much moisture the soil will normally retain without draining. High suction (several atmospheres) to measure water available to plants. And (theoretical) infinite negative pressure to measure absolute water content (which I assume is actually measured by heating, not "infinite negative pressure".)

It looks like salinity is then given as an equivalent of positive pressure. I think that means that if your plant needs at least 0.1 soil wetness at -12 bar to survive, but the soil is saline at an equivalent of +3 bar, your plant actually needs that particular soil to have at least 0.1 water content at -9 bar. In other words, salinity is the equivalent of drier soil, presumably due to its osmotic effect on cell walls.
Title: Re: Scaling Agriculture on Mars
Post by: MP99 on 10/10/2015 04:14 PM


Organics will build up fast enough from roots left in the soil from early harvests. Eliminating the toxic components is not that hard to do.

In fact such organics may cause a problem in hydroponic substrates. On earth massive amounts of water are needed to clean them. Cleaning may be more difficult on Mars.

Apologies for quoting an old post, just catching up on this thread.

I understand that supercritical CO2 is becoming a common solvent. Baring issues with compressing to the necessary pressures, could this be used for this cleaning activity?

Cheers, Martin
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/12/2015 04:56 AM
I've been a bit busy volunteering the last few days, but here is my catch up.

The technological level of genetic engineering and biological knowledge is such that creating completely artificial higher organisms belongs to the realm of science fiction. There have been papers in Nature or Science on creating artificial bacteria. Plants are a completely different ballgame. Plant cells are the most complex cells known, more complex that human cells since they contain more organs such as chloroplasts. We have a relatively good knowledge of how things work inside a cell, though they still do not cease to surprise us with new behavior. We have limited knowledge on how cells assemble functionally into an organ. To be clear: we know for example how a leaf photosynthesizes and how it moves water and photosynthates and how it is formed from the meristomatic tissue and how it fills up with waste products before it falls off. We are mostly speculating though on how each of these signals is propagated in the cell so that it knows how to do its part without interfering with the next cell or how to overdo its part when the cell next to it is lagging.

DNA is the blueprint of life. Just as archaeologists can discover the blueprints of a palace by digging but have to make educated guesses on room uses or political power structures in said palace, biologists often make educated guesses on what is actually happening. Sometimes these guesses are completely wrong, think how Lysenko brought massive famine to the Soviet Union believing in Lamarckism rather than Darwinism and trying to teach varieties how to have appropriate traits, instead of breeding appropriate traits into cultivars. Only a small percentage of DNA codes for proteins, the rest is called junk DNA though biologists have realized the last few year that it is anything but junk, it also has functions in the cell and beyond. Even for coding DNA we can read what amino acids are coded, but this does not mean that we know what the function of the protein they assemble into is. Monsanto has patented a gene that confers resistance to glyphosate (a.k.a. Roundup) by metobilising that pesticide. When they create glyphosate resistant soybeans (a.k.a. Roundup Ready) they first write that gene into the bacterium Agrobacterium Tumefaciencs . That bacterium infests soybean plants and produces cankers on the plants where it writes its DNA on the soybeans DNA at random points. Cells from these cankers are removed from the plant, are exposed to glyphosate and then those that do not die from it are selected. Then those cells are allowed to grow into plants and the most vibrant of them are bred with high yield soybeans. Then the plants that have the glyphosate resistant gene are selected and they are further bred into the varieties that are marketed. As I said, agrobacterium inserts its genes at random, often disrupting cellular functions (after all it is a pest). Breeders simply select the plants that do not appear to suffer harm from the infection, in reality we do not know what are the actual effects of insert the gene in the plant, guidelines for releasing new plant varieties, even transgenic varieties, are nowhere near as stringent as guidelines for new medicines, which is why especially in Europe transgenic crops are highly controversial: how do we know that like Mad Cow Disease or Alar or DDT it won't come back in twenty years to bite us back? To get back to the topic, if we want to create potatoes that above the ground have cactus like skin to survive Martian pressure transgenically, we would need to discover what is the metabolic path that leads to cactus' traits which can be a whole set of genes rather than a single gene, write it in the potato plant and see if it actually has any other side effects, such as giving the potato tubers the thick skin of cactus barks and rendering them inedible. In my freshman year as an undergrad almost 20 years ago our professor in the introduction to agronomy class told us that universities and seed companies are trying to produce the potato-tomato plant, which above ground produces tomatoes and below ground produces potato tubers (potatoes and tomatoes are very closely related). While there have been several experimental trials and varieties, such a hybrid has yet to reach commercialization.

Now though, transgenics is far from the only method available in the agronomist's and farmer's arsenal. There are several older and far less controversial methods available to modify plants. It is rather trivial to make a potato-tomato plant using the ancient method of grafting, which originated in China 4000+ years ago and is the method we used to domesticate fruit trees. Hybridization, that is making a new plant species by breeding closely related plants is also possible, corn is actually an artificial hybrid of teosintes created some 6000 years ago in the Valley of Mexico by early farmers that is not found in the wild. More recently colchicine has been use to create triticale, a plant that combines 90% of the hardiness of rye with 90% of the yield of wheat. This was never controversial because soft wheat (for example) was created some 24000 years ago by the natural merger of 3 related grass species and is actually hexaploid (it has 6 sets of genes, three from each parent). If we want to create a Frankenplant with the ability to survive in the Martian environment (ignoring for the moment planetary protection) we would need to find several closely related plants which have the traits and most likely know several genes that confer desirable traits and then somehow breed them conventionally and transgenically to create said. I am not saying it is impossible but it is a moonshot. It is far easier to create an artificial environment and grow typical plants, we have millennia of glasshouse knowledge and decades of hydroponics knowledge. Also, very importantly, plants are not known to grow in temperatures below freezing, lichens and such sturdy plants are good at going into dormancy and getting out of it when the situation is favorable, they do not grow during cold.

Water content is usually measured as volume of water in soil. Soils saturated in water are not 100% water, simply they have all their pore space filled with it. Plants such moisture out of the ground through their roots, their sucking power is measured in bars since plants use osmosis to pull water for the soil medium, when the plant cannot pull out enough water it wilts. Now there is variety of ways to measure salinity, my favorite since it is used in irrigation is electrical conductivity. Soils though also have their own salinity and irrigation is not only the management of water but also the management of salinity. When rainfall is below 500 mm per year irrigation turns soils saline and you need to drain the soils to avoid this (and better yet saturate at some point the soil to wash the salts down). Mesopotamia did not have a drainage network, which is why despite the good quality water of the Tigris and the Euphrates soils became saturated in salts, agricultural productivity fell (and we have the clay tablets to prove it) and in the end civilization collapsed at several points. Egypt though had drainage so their soils did not face this problem. Drip irrigation was invented where soils were too saline and water was also too saline and they needed to keep the soil wet enough to pull water but not completely saturated and have the roots die due to lack of oxygen (roots respire).

If you have any plant questions and need explaining, ask me, I will answer to the best of my abilities

Title: Re: Scaling Agriculture on Mars
Post by: sanman on 10/14/2015 02:40 PM
Yes and anything that could potentially grow on the surface will IMO not reach that goal. The temperatures are almost always too frigid to facilitate useful growth, they are barely enough for survival, not for meaningful production of biomass. That's why I believe whatever solution there will be the that greenhouse. It is cheap because it can consist of a very thin plastic foil, similar to what is done in Spain, but even much thinner foil because it does not have to stand up to severe weather. I am thinking 0,08mm.

My guess is the most productive will be algae circulating in transparent pipes or plastic hoses under a greenhouse roof. Those pipes don't need to be very thick. Just enough to contain a minimum of pressure like 150mbar or 3psi. Algae might be optimized for different nutrients by genetic manipulation or simple breeding. Probably oil and starch. Maybe one algae that produces both can be most efficient.

However, the effort to engineer something incredibly exotic that can survive outside seems to waste the potential for engineered plants to be part of the internal ECLSS. And I would think, if we're broaching the idea of that level of bio-engineering, an engineered "all-in-one ECLSS plant" living inside your habitat would be an easier goal than "surviving below-freezing in an irradiated near-vacuum and growing fast enough to feed the settlers".

(Even just engineering a food plant that can tolerate high CO2 levels. So that you can simply pressurise atmospheric CO2 in a greenhouse. Lets you expand food production faster than trying to build systems that can stay within the finicky narrow CO2/O2/H2O/pressure limits required by natural plants.)

Mars has a huge amount of land area. If some plant could be engineered to grow on the surface, then that creates the potential for a huge amount of plants being grown. Even if a small fraction of that plant mass is useful biomass, collectively it would still add up to a lot.

But suppose we could improve the situation by selecting some area of Mars which has more favorable surface conditions? Hellas Basin, maybe? It's said that the triple-point of water could exist there. Or what about the Martian equator? Temperatures get quite warm during the day.

So if you could select the right locale, then maybe that outdoor environment isn't quite as harsh as everywhere else on the planet. Then you can get that savings on infrastructure (eg. greenhouses, etc)

Which locale on Mars would be the most ideal for Martian agriculture? You want to use every bit of advantage you can get.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/14/2015 04:55 PM
There is one problem with plants outside. The oxygen produced would be lost. With plants in a greenhouse you can have a closed circle for all materials involved. Not so with plants outside. That may be OK for plant matter that is used as a raw material for furniture and construction. Not for food where the oxygen is needed to close the circle.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/14/2015 06:51 PM

Mars has a huge amount of land area. If some plant could be engineered to grow on the surface, then that creates the potential for a huge amount of plants being grown. Even if a small fraction of that plant mass is useful biomass, collectively it would still add up to a lot.


Earth and Mars have been exchanging biological material for billions of years. If some Earth species could have thrived on Mars and considering the mutagenic capacities of the Martian surface (e.g. UV bombardment), I think it would have evolved something that could grow on Mars. There is no higher species, plant or animal, able to survive the current natural Martian Environment. All the discussion is about microorganisms. If we could establish large scale photosynthetic organisms on Mars, the end result would be a Martian Great Oxygenation Event and global cooling.

Quote
Which locale on Mars would be the most ideal for Martian agriculture? You want to use every bit of advantage you can get.

Speaking for greenhouses here, it would be somewhere warm around the equator, near sources of nitrogen. The largest expenditure in a greenhouse is heating during the night
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/14/2015 07:05 PM
Lights should provide some heat.  Since they will be producing methane for rocket fuel, some could be burned for heat at night in natural gas heaters.  This would also put some water vapor into the greenhouse atmosphere when burning at night.  Another passive solar way would be to heat water during the day and have it release it's heat at night.  Water will have to be stored somewhere.  I've seen pictures of a home that does this in Arizona.  They used sliding glass doors with black 55 gallon drums of water behind the.  Then they had solid insulated garage doors that closed over the sliding glass doors at night.  Drums got hot during the day, then released their heat all night.  The reversed the process in summer.  They opened the sliding glass doors at night (the had sliding screens behind them to keep out insects and such).  This cooled the drums, then they closed the garage doors in the day.  The cooled water then cooled the house during the day.  Simple no energy solution.   Garage doors were on timers.  The home was fairly long as each room had this set up. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/14/2015 07:48 PM
The martian atmosphere is thin. It does not transport heat like earth atmosphere does. A thin infrared blocking plastic foil will make a perfect greenhouse. The soil will provide the buffer. Warmed by sunlight during the day it will emit infrared during the night that will not escape.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/14/2015 09:54 PM
High humidity in the greenhouse is an invitation for fungal diseases. On Earth greenhouses actually dump their atmosphere at night when the cooling brings relative humidity to 100% and replace it with the cold air outside which they heat, in order to avoid high humidity. An internal IR reflective surface is great, so long it does not reflect IR radiation coming from outside, this is why blankets are often used instead.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/15/2015 01:55 AM
A post on something I owe from earlier MELISSA. I saw the website which has not been updated from 2006 and it confirmed what I read from the paper I have shared earlier in this thread: MELISSA is not a farming system, it is a life support system. Yes, food is produced, and 10 kg of freshly food that you don't have to bring from Earth gives margin for other things but it is not a prototype of how a future farm will look like. On the other hand it is a very interested experiment in closed systems and I think it would be better for the hab or the transit spaceship than the mechanical ECLSS system used. Let's not forget though, the ISS ECLSS has been working, with limited parts resupply for year. While MELISSA has been used at Concordia, it has never flown to space. My thinking (but I am not an engineer) is let's have both ECLSS systems, MELISSA for the food and the conventional system as backup. Then again, this means extra weight ...
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/16/2015 02:27 PM
MELISSA is not a farming system, it is a life support system. Yes, food is produced, and 10 kg of freshly food that you don't have to bring from Earth gives margin for other things but it is not a prototype of how a future farm will look like.

On Mars or any permanent settlement off earth life support system and farming system will be one and the same. MELISSA to me looks like the nucleus of such a system. With emphasis on the recycling/life support part just because that is what needs development most. The farming aspect is more known territory so they did not emphasize that part.

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/20/2015 09:46 PM
There are a couple of articles related to agriculture on Mars, inspired by the Martian movie:

http://www.thestar.com/news/world/2015/10/05/guelph-scientist-learning-to-grow-crops-on-mars.html

Canadian scientists apparently use pressure chambers to see what are the minimum requirements to grow crops on Mars

http://spaceref.com/learning-how-to-farm-on-mars.html

Washington State and Idaho state have created a mini course to gauge ideas on how to grow food on Mars which they give to the lab rats ahem students
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/20/2015 09:58 PM
If food can be grown in greenhouses on Mars, they can be grown in O'Neal space cities also, and on giant spaceships that can travel around the solar system, or eventually to other star systems.  Mars can and will be a testing ground for agriculture that can actually help earth in the long run.  At some point, all our fresh vegetables could be grown year round on earth in greenhouses instead of just once a season in the open.  If you can get two to three crops a year in greenhouses, farmers on earth can double production on half the land.  Greenhouses can keep out insect pests with double doors and do away with insecticides.  Extra land available from not farming could grow cattle, pigs, or chickens. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/21/2015 12:29 AM
Fresh crops ARE grown year round in greenhouses and have been grown for several decades, summer being the main issue due to heat but there are cooling panels for that purpose. You can have three crops a year, or you can have a plant like tomatoes or cucumbers that set new fruit year round rather than once as wheat does. The issues facing greenhouses are economic rather than agronomic, it is much cheaper to grow if you don't have to heat the air. On any space station the issue becomes element management: you can create N fertilizer out of the Martian air, though I have not see any colonization plan yet which had an ammonia production facility as part of the colony. P and K can come from rocks, if we can get to appropriate ones. Where would you get fertilizer on a space station without resupply? How do you manage the nutrient cycle, releasing the elements out of the waste products to use them again? Indeed, Mars is a simpler proposition that any space station
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/21/2015 03:49 AM
We can get phosphor from waste water treatment plants. Even if we have all raw materials as deposits I expect a Mars colony to use a near perfect cycle that needs significant input only for growth.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/21/2015 04:54 AM
Phosphorus in waste water treatment plants mostly comes from laundry detergents. I seriously doubt that the quantities used in the colony can support agriculture. After a point we would need to chose how closed a loop we want. Carbon assimilation by plants will be higher than what we consume in food. We need to release most of the elements in the plant matter but we would also want to sequester the heavy metals which seem to be common in the Martian soil and will show up in the plant even if we use the soil only as a substrate for hydroponics. The starter greenhouse will very likely have most of the fertilizer for the first crop shipped from earth, but we will need to set up a production facility for the next crops. Here is my thinking for the first farm kit:

One high strength clear PVC cover greenhouse, designed as a pressure vessel
Earth origin substrate (e.g. rockwool, coco-peat) that will be compared with Mars soil as substrate. Can be packing insulation
Heating units, blankets, high-efficiency high-power supplementary illumination lights
Pumps and irrigation plastic hoses and drippers
Benches
Seeds
ECLSS output sending CO2 to the greenhouse air (plants have no problem with CO)
O2 concentrator removing photosynthetic oxygen to ECLSS
Enough fertilizer for the first crop
Chemical synthesis reactors to make fertilizer for the future
Fungus innoculum (preferably pleurotus) for decomposition of plant fibrous materials into food (on a separate unilluminated room)

I see an algae line as the very first crops but more palatable food will follow
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/21/2015 06:24 AM
Phosphor in detergents is prohibited in the EU. I am also quite sure that at least in Germany they have not been used a long time before they were prohibited. Phosphate recovery is almost cost competetive at present prices.

I believe a Mars colony will work to have a very much closed circuit ecology.
Title: Re: Scaling Agriculture on Mars
Post by: Kenm on 10/21/2015 06:43 AM
It looks like Azolla (duckweed fern) is a good plant for fixing Nitrogen and generating oxygen with some space related work already done.
http://theazollafoundation.org/features/space-and-planetary-colonization/
It's also good for integrated rice/azolla/fish/duck crops.

I thought that the amount of fertilizer needed to feed a person for a year was only on the order of tens of Kg so we should be able to bring a supply for several years.

Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/21/2015 07:59 AM
I thought that the amount of fertilizer needed to feed a person for a year was only on the order of tens of Kg so we should be able to bring a supply for several years.

Most of that would be nitrates. Given fuel ISRU produces hydrogen and nitrogen gas it is very easy to produce ammonia further reducing transported mass. But true it is easy to transport in the beginning. More so because for an initial small group most calories would be imported. Growing food will begin with vegetables and herbs.

Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 10/21/2015 03:08 PM
We can get phosphor from waste water treatment plants. Even if we have all raw materials as deposits I expect a Mars colony to use a near perfect cycle that needs significant input only for growth.
I expect that sewage will be sterilized, and possibly treated to remove problem chemicals like heavy metals, then used as fertilizer.  Same for biomass left over from food production.  Extracting individual nutrient compounds shouldn't be needed.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/21/2015 03:16 PM
Algae can be grown first, then made into pellets or just as is to feed Tilapia and chickens. Tilipia eat algae and produce fertilizer.  Chickens produce fertilizer, eggs, and meat.  The fertilizer both produce can be used to fertilize higher scale eatable garden plants.  All within a closed system.  Grains initially will have to be brought from earth until larger greenhouses can be built to sustain them. 

Sheltered living areas along the sides of long greenhouse flexible plastic tubes can be used to retreat to in case of puncture of the plastic.  A repair team can access this with an electric lift and patch kit.  Sections of this thick plastic greenhouse can be replaced periodically.  These sheltered areas can have water storage above them to help with cosmic radiation along with some regolith along the outsides.  Solar panels can be along the top of the water storage and along the sides of this system initially.

Plastic greenhouse material would have to be a manufacturing priority for replacements and expansion of living and growing areas. I have see a double wall inflatable plastic greenhouse material used on local commercial greenhouses.  This could be filled with water, which is clear, to allow sunlight to come through to the plants while at the same time providing cosmic radiation protection and gravity fed pressure water systems.  Internal heat from nighttime greenhouse lighting would keep the water from freezing.  flooring and internal walls of the greenhouse could be painted black to absorb sunlight heat during the day to be released at night.  Greenhouses could be long an narrow to make it easier for clear plastic patches and or replacements to be installed.  Replacements would have to be done at Mars atmosphere in suits or robotically and food would have to be rolled out of a greenhouse under repairs. 

Sewage from humans, tilapia, and small animals can all be used for fertilizers and methane production.  Methane being a byproduct that can be used in rocket fuel or for supplemental heating.  I do think heating will not be a problem even on cold Mars.  With regolith and water around the living/growing areas thick enough, body heat, heat from lighting, cooking, machinery, computers, and appliances, there should be enough to sustain the colony without much supplemental heat.  In my home, which is insulated and has double pane windows, we do not need to turn on the forced air heat until it drops below 35-40 degrees, depending on wind.  Several feet thick of regolith and water along the sides and tops of living areas as well has heat absorbing black paint on the insides of the greenhouses, there should be very little if any need for supplemental heat.  Burning methane as supplement would put water vapor into the greenhouse areas as well as some CO2 which really would not be needed, but it won't hurt the plants.  O2 produced by the plants can be scrubbed out of the greenhouse air and piped into the living areas working areas along the sides.

All of this can be built starting small scale and added on, extended on the ends and expanded as more colonists and supplies arrive. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/22/2015 02:26 AM
We do not want moisture in greenhouse air, optimum range is below 80% relative humidity. Also, I do not see animals of any form early, the same calories from animals cost 3 times as much food than when they come from plants. Animals will be introduced when there are enough plant byproducts to survive on a diet composed mostly of them, not on food grown specifically as animal feed. O2 habitat control is going to be a major issue with a greenhouse present, the first lethal stumbling block on MarsOne is exactly excessive oxygen leading to danger. I do see oxygen eventually getting vented after all the tanks are full to capacity. I am open to all suggestions for adding CO2 to the greenhouse air, I propose the Martian air mostly due to convenience, it might not be the best option. On another note naked flames are best avoided in greenhouses, in heaters the flame is kept inside a box rather than being directly exposed to the greenhouse air
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/22/2015 05:36 AM
If all plant matter is composted and kept in the cycle there would be no excess oxygen.

I think at least fish, probably shrimps too could be produced quite early. For the reason that algae are the cheapest calories by far to produce on Mars. Besides feeding fish methods need to be developed how to process algae into palatable food for humans.
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 10/22/2015 05:04 PM
Animals are useful for converting plant matter not directly edible to humans into food.  Of course you'll need to select species not requiring too much human edible food for that to be efficient.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/22/2015 05:22 PM
If any of you have ever subsisted on dry or dehydrated foods, soy protein, etc.  It gets old real fast.  I''m also alergic to soy and soy products, peanuts, milk and milk products.  Same with MRE's with the military.  They get old real fast.  I'm not against an algae based foods, but tilipia do eat algae and grow from eggs to full adults in 2-3 months.  If you've ever eaten powdered eggs, they too get old fast.  So, algae can be dried and pressed into pellets for chicken and larger fish feed.  Chickens make real eggs and also can grow from chick to eatable size in about 3 months. Both the fish and chicken waste is some of the best vegetable fertilizer there is.  My grandfather raised chickens, so did my parents in law.  My son is an aquaculture major.  Enough fish can be grown by aquaculture in a 4' x 6' x 8' tank to feed a family of 4 one meal of fish a week.  The average laying hen in America lives in a 1 cubic foot pen, lays 2 eggs a day.  When she quits laying 2 a day, she is sent to the meat market.  These same small space methods can provide real food for people that can satisfy the palate.  Eventually miniature cattle, goats, and sheep can be introduced, for milk, food, and wool.  Even a small Jersy milk cow can produce 2 gallons of milk a day.  A goat about a gallon a day.  Pelletized algae could feed them all.  I've read of families that can grow their entire food supply in less than half acre, using extensive aquaculture, small animals, and greenhouses.  In an enclosed environment like a Martian greenhouse, why not Mars.  24 hour days and the advantage of Mars is lighting can continue the growing process for algae and plants at night.  Lights at midnight wake up chickens and they lay an egg like on earth.  Then at sunrise, they lay another one. 

Agriculture would have to start immediately after rocket fuel production.  That way massive amounts of food would not have to be transported to Mars on every MCT.  It would also have to be continuously expanded with more and more greenhouses being built.  Some can then specialize in what they produce. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 10/22/2015 05:54 PM
If any of you have ever subsisted on dry or dehydrated foods, soy protein, etc.  It gets old real fast.  I''m also alergic to soy and soy products, peanuts, milk and milk products.  Same with MRE's with the military.  They get old real fast. 

Multi allergic people will probably not be among the first settlers. But the need to accomodate them will arise soon enough with children born on Mars. So food alternatives will need to be provided.

Dry food would IMO not be what you suggest, except during transit. On Mars with gravity real cooking can be done. I see dry food as flour, sugar, noodles, vegetable oil, rice, lentils, beans, powdered milk, powdered eggs, dried apples and apricots. There sure can be more dry goods. Maybe minced meat can be freeze dried and restored to an acceptable texture?

Yes, food production will probably start with the very first landing. But fast growing vegetables like tomatoes, bellpeppers, cucumbers, herbs, onions, garlic. Tilapia from algae I mentioned already. Chicken can follow soon, also fed from algae, extracted and pressed to pellets, but not immediately. Protein for feedstock can be provided by algae grown in vats from methane and ammonia or another source of nitrogen. There is already a permit to use that for animal feed in the EU.

With those ingredients you can bake fresh bread, cakes and cook reasonable meals, especially if you have at least some frozen meat. It won't be too much mass per person/day. Not at all comparable with military MRE or what they get at the ISS.
Title: Re: Scaling Agriculture on Mars
Post by: nadreck on 10/22/2015 06:33 PM
Rather than trying to exactly "close the loop" on the total air/water/food generation system the objectives should be to reduce imports from Earth as much as possible as the highest priority and recycling waste as a more secondary objective. That there may end up with a continuous surplus (waste) of oxygen, water, nitrates etc. is not particularly important that there is such a surplus. It is probably in the best interests of growing settlements on Mars and for the general "off Earth" economy to produce surplus air, water, food, propellant that is stockpiled and potentially sold to other groups doing other things beyond Earth.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/22/2015 06:51 PM
I once was not allergic to the things I mentioned.  In the last few years I have become that way.  I am allergic to hydroponic tomatoes, but my home grown, vine ripened, I seem to do just fine.  I think a lot of our food has been modified in the last few years.  Never had this problem before.  It causing excess acid, bloating and such.  Got allergy tested, and that is what they said. I've eaten anything and everything all my life.  Now, that being said, the doctor said the food allergies can come and go.  He said if you eat a lot of the same foods, especially daily, your body can get tired of them, thus the variety will be needed. 

They do have freeze dried meats.  The Mormons store them.  Almost anything freeze dried.  Too much and they can dehydrate you if you don't drink enough water with them, even after hydrating and cooking.  That is why they suggest fresh garden vegetables to supplement what they store.   
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/22/2015 08:21 PM
Here is another article, this time time actually mentioning hydroponics for agriculture on Mars:

http://arizonasonoranewsservice.com/u-scientists-make-gardens-mars/

Between carbon assimilation and decomposition there is going to be a time lag. Also we want some organic matter to help sequester potentially toxic substances such as heavy metals, if we do not throw away part of the organic material we might get bioaccumulation of toxic material. In any case there will always be live plant matter photosynthesizing, after all we harvest only a small part of the whole plant. Honestly, so far we have no experience with farming outside the earth (though Antarctica analogues come close), most experiments have been biological rather than agronomic. The best we can do is speculate.
Title: Re: Scaling Agriculture on Mars
Post by: llanitedave on 10/23/2015 12:48 AM
Composting waste organic matter also relies on a complex bacterial ecosystem.  It will take just as much effort to keep those bacteria healthy as it will to grow the crops themselves.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/23/2015 01:32 AM
I am not thinking of composting, I am thinking of using the plant stems for pleurotus mushrooms. After drying the material you put them in a bag or more likely bale, add pleurotus inoculum and put the bale in a dark room. In a week you start getting edible pleurotus mushrooms, very tasty when fried on a pan with olive oil, and at the end you will have inside the bale a mixture that can be directly used as compost. But yes, direct composting is complex.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 10/26/2015 02:44 PM
Another article, this time the interviewee is closer to my thinking:

http://www.cnet.com/au/news/leaf-on-mars-could-we-grow-a-garden-on-the-red-planet/
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 10/26/2015 07:37 PM
I also do not think there will be much excess oxygen.  Most will be made into rocket fuel, with enough for breathing.  Any moisture in greenhouse air can be dehumidified for potable water or for replenishing water in fish tanks and algae tanks.  Eventually sewage from humans and small animals can go into methane digesters for producing methane for rocket fuel and/or heating.  Waste from the digesters is fertilizer for the plants.  I also do not think composting is that hard, especially with some machinery to keep it stirred or tumbled.  I've grown vegetable gardens for years, and it is not that hard.  Chickens and rabbits make great fertilizers, as well as fish.  To me actually better than chemical fertilizers. 

I do agree they would have to start with algae.  Algae will be the basis for oils, synthetic foods, but also food for fish and chickens.  Once you build up a supply of fertilizer from the animal wastes, then a multitude of vegetables can be grown. Vegetables will start with the fastest growing varieties first, then as expansions are done, longer growing varieties, then eventually grains.  Actually a space of about 100'x100' can grow enough wheat for a family of 4 for a year.  The straw can be used as animal feed or for composting.

I do know one thing, rice is heavy but dense in nutriants, but does require a lot of water.  Wheat and corn require less water. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 11/19/2015 06:26 AM
What you are talking about is more farm practices than actual crop requirement. Rice requires 900 mm of water because the agricultural practice is field flooding. The actual plant itself requires less, the important coefficient here is called Kc and it is the ratio of plant transpiration to reference evapotransiration for that particular atmospheric condition. Wheat can be grown with 400 mm water, but its yield will increase with more humidity up to a point. There is a difference of optimum water use for maximum production and minimum water use to have some kind of production.

Now I have been thinking, each meal is a few hundred grams. Let's assume that our colonists consume 1kg of food per day, and that we have 4 colonists as the MarsOne concept. We will need to produce and store 1,5 tons of food per year. Assuming we want to keep a buffer, since after crop production timing and consumption will differ and that we keep a buffer of 1 year, we would need to store in controlled environment 1,5 tons of food. Now also there are several ratios out there on how much water is necessary for each kg of food which depend on the type of food (more for meat, less for plants) but even the most efficient condition is 8 kg of water per kg of food. One year production for the 4 colonists will require 12 tons of water, and although we will constantly recycle the water, wouldn't it be wise to also keep on years supply of water on hand just in case? I am not sure how much a pressure vessel greenhouse would weight, but it could be dwarfed by the consumable requirements for agriculture

Everyone feel free to correct my numbers wherever I am wrong.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 11/19/2015 07:18 AM

Everyone feel free to correct my numbers wherever I am wrong.

Who here would know better than you?

But some numbers I got from the recent NASA workshop for selecting a landing site. They set a requirement for ~100t available loacal ISRU water assuming 3 times 500 day stays of 4 astronauts at that location. Some of that water would go into food production. For each of the ~40 proposed landing sites the availability of water was given in multiple km³ with the largest amount given for one single landing site was 20000km³. so available water is not an issue. Equipment to mine it though could be a limiting factor.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 12/27/2015 03:47 PM
There is a new article on the Telegraph, most likely inspired by this year's Royal Institution lecture for children on how to survive Mars. It deals both with surface and station grown plants, and talks in length about MELISSA

http://www.telegraph.co.uk/gardening/how-to-grow/how-to-grow-space-age-veg/
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/30/2015 03:32 PM
Are there any developments in synthetic food? There's plenty of work done on taking food, and converting it into biofuels. How about the reverse?

On Mars, we have water and CO2, so can synthesise Alkanes and alkenes. Presumably it should be possible to synthesis alcohols, which humans can use as a source of calories.

Is it possible to directly synthesise something for calories for humans?

Next question, is it possible to synthesise something for algae, which can be grown either for food for humans, or food for fish and perhaps chickens? Growing algae is more efficient than normal crops so really ought to figure in the production of food.

Basically, the aim is to replace carbohydrates which should make up the bulk of calories, with synthetic or algae created food. The "farm" can then concentrate on tomatoes and salads (ultra high yield, because they're mostly water), and chicken and fish feeding off the algae.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/30/2015 04:51 PM
Are there any developments in synthetic food? There's plenty of work done on taking food, and converting it into biofuels. How about the reverse?

...............
Basically, the aim is to replace carbohydrates which should make up the bulk of calories, with synthetic or algae created food. The "farm" can then concentrate on tomatoes and salads (ultra high yield, because they're mostly water), and chicken and fish feeding off the algae.

Actually there is one development, that is very interesting. Producing mostly protein from methane, a nitrogen source like ammonia, and some trace elements that feed bacteria. The product is already approved for animal feed in the EU. For direct human consumption there are still some obstacles but it could be done. Methane will be produced in large quantities on Mars. Ammonia can also easily be produced from the nitrogen in the martian atmosphere. Easily that is with abundant power production.

Microalgae do produce carbohydrates very efficiently. They also produce high quality oil. Algae as basis for food production is my favorite theme here. :)

So all basic requirements for feeding humans would be available. The trick is to convert them to palatable food. Maybe you can feed a group of scientist Astronauts with green goo. But if you want people to go and colonize Mars, having a family and children it will require a reasonable tasty food supply. Even if it takes some getting used to as it is not sourced from wheat, corn and rice.

Edit: I suggest you read this thread. It is not too long and lots of things have been discussed here.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/30/2015 07:26 PM
Do you have any information on methane > protein? (Most of the literature is on the reverse process).

Quote
The trick is to convert them to palatable food.

As you state above, Chicken and fish are pretty good at that. I recall 1.5 units of algae give 1 unit of Tilipia, which in theory means Tilipia gets a higher yield per m2 than potatoes.

Quote
I suggest you read this thread. It is not too long and lots of things have been discussed here.

I contributed near the start, basically disagreeing with the premise of growing what we refer to as "crops" on Mars using hydroponics. I now see you've added a lot about algae - thanks for that.

I'm still not clear on whether the conclusion is that we can avoid the hassle and expense of growing potatoes and corn - i.e "crops", and make do with algae products (including fish/chicken), methane products, alcohols (Phobos-shine :)) and salads/tomatoes.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 12/30/2015 08:01 PM
The general idea is that usually we do not directly convert abiotic substances to food. The main issue is purity, biological organisms are selective metabolizers and will generally clean the substance they produce. On the flip side lies bioaccumulation, but generally living or recently deceased organisms make better choices for nutritious food. The Mars agronomic system will diverse and resilient to avoid single points of failure. Expect algae and cereals, tubers and fruits. I have been reading on long duration flights and one of the things noted is that people is small spaces, whether prisoners or astronauts on a spaceship (and perhaps colonists?) obsess over food. Having a semi-artificial paste as food several times a day for days on end (let alone years) will only lead to mutiny. A variety of crops makes sense for both agronomic reasons (fewer disease and pest risks), nutrition reasons and psychological reasons. The flip side though is that it will require more labor than monoculture.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/30/2015 09:31 PM
Do you have any information on methane > protein? (Most of the literature is on the reverse process).

My bad. I just realized I forgot adding that it is bacteria that feed on the raw materials and do the conversion. Edited the post accordingly.

Quote
The trick is to convert them to palatable food.

As you state above, Chicken and fish are pretty good at that. I recall 1.5 units of algae give 1 unit of Tilipia, which in theory means Tilipia gets a higher yield per m2 than potatoes.

Yes, that's one way. I am thinking of something else though. This is just an idea right now but I believe it will become possible. Much of the base of our food are different types of flour. Wheat flour, rye flour, rice flour. I hope that reasonable substitutes can be produced from algae starch and suitable types of proteins produced in bio reactors from bacteria or funghi to give the starch the desired properties. After all all types of flour are starch plus a small amount of protein. From that noodles, bread, other bake products can be made. Lots of products for vegetarians copy meat products using plant protein. Make similar products from bacterial or fungal protein.

That leaves the greenhouses for vegetables, onions, garlic, herbs.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/30/2015 10:50 PM
The general idea is that usually we do not directly convert abiotic substances to food. The main issue is purity,

Or is it that we are short of energy, but have lots of food? That is why all the effort is on biofuels - converting "food" into fuel into energy, not the other way round.

Quote
I have been reading on long duration flights and one of the things noted is that people is small spaces, whether prisoners or astronauts on a spaceship (and perhaps colonists?) obsess over food. Having a semi-artificial paste as food several times a day for days on end (let alone years) will only lead to mutiny.
Probably not an issue on Mars. More like a lack of willing colonists.

Quote
A variety of crops makes sense for both agronomic reasons (fewer disease and pest risks), nutrition reasons and psychological reasons. The flip side though is that it will require more labor than monoculture.

The point though is that methane or algae are a base food. Algae can be converted into Tilipia and Chicken (and eggs). Some types can be eaten directly. I don't know if it can be turned into something that tastes like Spinach, or Wheat (as guckyfan suggests above).
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 12/31/2015 03:14 AM

Or is it that we are short of energy, but have lots of food? That is why all the effort is on biofuels - converting "food" into fuel into energy, not the other way round.


The main policy reason behind biofuels is to protect farmer's prices from going to low. With the notable exception of Brazil (which however is a food exporter) most biofuel programs come in the EU and US which are rich, food exporters and are more worried about keeping their farmers happy and not so much starving third worlders. In any case shortage of food in the Third World is an issue of social justice rather than lack of production. As policy wonks have repeatedly said in Agronomy Society of America conferences and other similar venues poor farmers could easily raise their yield with fertilizers and improved seed. Problem is that even if they do, often the logistic network bringing food to the cities cannot support transporting more food to urban consumers. If you divide the quantity of food available in most cities with the population nobody should be starving. Those starving do not have the means to earn income to buy food.

Quote

The point though is that methane or algae are a base food. Algae can be converted into Tilipia and Chicken (and eggs). Some types can be eaten directly. I don't know if it can be turned into something that tastes like Spinach, or Wheat (as guckyfan suggests above).

Biological systems are not 100% efficient. Algae can be converted into animal mass by feeding, but you would get more calories per farm area with plant crops than with animals. Also with animals you get related issues such as manure management. Even if you grow algae just for animal consumption you will most likely also need to have a soil or soil less based crop in the next enclosure just to manage manure, biosolids etc. It is far more efficient to recycle nutrient than to throw them away and create new ones. In Mars nitrogen, which is so crucial to agriculture, is a minority atmospheric component and just as the colony will manage Oxygen or Carbon they will also need to manage Nitrogen is a loop more closed than anything on Earth. I am all in favor of algae, especially spirulina but as part of a diverse portfolio of crops
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/31/2015 05:59 AM
Biological systems are not 100% efficient. Algae can be converted into animal mass by feeding, but you would get more calories per farm area with plant crops than with animals. Also with animals you get related issues such as manure management. Even if you grow algae just for animal consumption you will most likely also need to have a soil or soil less based crop in the next enclosure just to manage manure, biosolids etc. It is far more efficient to recycle nutrient than to throw them away and create new ones. In Mars nitrogen, which is so crucial to agriculture, is a minority atmospheric component and just as the colony will manage Oxygen or Carbon they will also need to manage Nitrogen is a loop more closed than anything on Earth. I am all in favor of algae, especially spirulina but as part of a diverse portfolio of crops

I disagree to one point.

Algae production can be done with water running through pipes. This is so much more efficient on Mars than other crops that quite possibly even going through tilapia and chicken yields more efficient calories than our earth staple plants. The manure management with animals I see using bioreactors, very compact and efficient. The nutrients go directly back into algae and/or conventional plant productions.

People will not want to eat green goo, no matter how efficient. It may do in times of crisis but not under regular conditions. I keep coming back to people who want to go there and raise their children. But I agree partly the algae and methane algae products will be base material for food technology producing analogs to many earth products. I mentioned special products for vegetarians.

I agree that it needs to be a very efficient closed cycle system for the nutrients. Unlike earth where the living environment does it for us we need to manage. I cannot envision millions of tons of organic waste compiled on a dump out of sight of the colony. Though as a byproduct of methane fuel production there will be a huge amount of nitrogen that can be converted to ammonia or nitrates that process will need higher energy input compared to cycling.

I agree to the diverse portfolio of plants. That will be vegetables, fruit (banana, strawberry). I just cannot see large scale staple food production in wheat or rice fields.


Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/31/2015 09:24 AM


Biological systems are not 100% efficient. Algae can be converted into animal mass by feeding, but you would get more calories per farm area with plant crops than with animals.
According to: https://en.wikipedia.org/wiki/Photosynthetic_efficiency, Algae are at least an order of magnitude more efficient than crops at converting sunlight into glucose.

If Tilipia and chickens can then convert that into animal protein at 50% efficiency, then Tilipia and Chicken are at least 5 times more efficient than crops.

Add to the fact that algae can be grown in bio-reactors, and fish in large tanks, and the whole process is a lot easier - especially if you don't have access to fields and soils etc.

Quote
Also with animals you get related issues such as manure management. Even if you grow algae just for animal consumption you will most likely also need to have a soil or soil less based crop in the next enclosure just to manage manure, biosolids etc. It is far more efficient to recycle nutrient than to throw them away and create new ones.
I think all human and animal waste should be sterilised and fed to the algae.

Quote
In Mars nitrogen, which is so crucial to agriculture, is a minority atmospheric component and just as the colony will manage Oxygen or Carbon they will also need to manage Nitrogen is a loop more closed than anything on Earth.
Agree about the nitrogen - and it's often raised as an issue for building very large colonies. However, Mars' atmosphere is 2.7% Nitrogen, and I think there will be a lot of atmospheric scooping to get CO2 for rocket fuel.
(Also a lot of Argon - for breathing, is Argon as good as Nitrogen?)

Quote
I am all in favor of algae, especially spirulina but as part of a diverse portfolio of crops
If we need a diverse portfolio of crops, then that's what we'll have to do. But if we can find a way to use algae to provide the bulk of the calories, and dispense with the "calorie crops", Mars will be a lot, lot easier.

Put it this way, if the cost is: Algae: $10/kg, Fish: $30/kg, Potatoes, Bread and Rice: $200/kg,
1. There's a big incentive to find a way to convert algae to something that looks like bread.
2. We'll eat more fish and less potato.


Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/31/2015 09:41 AM
I also see that algae are quite radiation tolerant, so could be grown using natural sunlight, by running them through (double walled) glass tubes on the Martian surface, or even in orbit. Perhaps even with solar concentrators.

That is going to be a lot cheaper than any form of greenhouse and could be more efficient than using LEDs.


My bad. I just realized I forgot adding that it is bacteria that feed on the raw materials and do the conversion. Edited the post accordingly.
Is there any point to this if algae do a better job? Or is it producing something different that the algae can't, or is it more efficient?

Quote
Yes, that's one way. I am thinking of something else though. This is just an idea right now but I believe it will become possible. Much of the base of our food are different types of flour. Wheat flour, rye flour, rice flour. I hope that reasonable substitutes can be produced from algae starch and suitable types of proteins produced in bio reactors from bacteria or funghi to give the starch the desired properties. After all all types of flour are starch plus a small amount of protein. From that noodles, bread, other bake products can be made. Lots of products for vegetarians copy meat products using plant protein. Make similar products from bacterial or fungal protein.

That leaves the greenhouses for vegetables, onions, garlic, herbs.

There's a lot of work going on, but mostly for health supplements. We still need the outside bit of the Tilipia sandwich.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/31/2015 12:26 PM
I think all human and animal waste should be sterilised and fed to the algae.

It takes a little more than sterilizing. All organic compounds need to be broken down to anorganic compounds to be usable as plant nutrients. On earth it happens mostly in the soil or by funghi breaking them down. In fish tanks like the ones I had at home for a long time it is done in filters. That work would be done in bioreactors under controlled conditions. It yields CO2 and methane besides anorganic nutrients.

However, Mars' atmosphere is 2.7% Nitrogen, and I think there will be a lot of atmospheric scooping to get CO2 for rocket fuel.
(Also a lot of Argon - for breathing, is Argon as good as Nitrogen?)

I did some searching on that matter and have not found anything conclusive however it looks like a mix of nitrogen and argon would be suitable for breathing.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/31/2015 12:33 PM

My bad. I just realized I forgot adding that it is bacteria that feed on the raw materials and do the conversion. Edited the post accordingly.
Is there any point to this if algae do a better job? Or is it producing something different that the algae can't, or is it more efficient?

I don't have an answer regarading efficiency. I am just pointing out a proven method. However the process yields mostly protein. So probably different than algae in that regard. Algae produce more carbohydrates and oil. All three nutrients are needed so they may be complementary.
If you want to raise chicken, shrimps and fish more palatable than Tilapia, like trout then adding protein to the feed might improve yield. If you want to raise rabbits pure algae pellets may be the best food.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/31/2015 12:57 PM
If algae produce mostly carbohydrate, then it should be possible to get something that resembles bread, pasta, rice or potato out of it.

I'm happy with Tilipia and Chicken for the protein. And maybe some tomatoes and lettuce for the vitamins.

As for sterilising the waste - it's a bit more than what Mark Watney had to do! So:

Waste collection -> Anaerobic digesters -> Algae -> Fish and Chicken -> Eggs
                                                                              -> Algae "flour" -> Bread
                                                                              -> Directly edible algae
                                                 Methane -> Bacteria -> Protein -> ?
                                                                                  -> plant nutrient -> Tomatoes
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 12/31/2015 01:49 PM
On the feed conversion ratio wikipedia has a pretty interesting article:

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

Now when you read that poultry has a feed conversion ratio of 1.38 to 1 (claimed by a New Zealand poultry producer) be aware that they have optimized the feed mixture. I looked up the internet and found a manual in Greek which had a standard meal for chickens on page 169 table B5. While this is not the book we did in class as an undergrad I can certify you that it has a pretty similar content:

http://blogs.sch.gr/andratha/files/2014/09/diatrofi_agrotikon_zoon-aa.pdf

Since I doubt there are any other Greek speakers reading this thread I am going to give you a translation of the gist. On the vertical axis are six major nutrition categories that feed must provide: Metabolic energy, Total Nitrogen, Lysine (an amino acid), Ca, P and Na. On the horizontal axis are the animal age in weeks, for the first three columns it is for egg producing animals, the next three are meat producing. This particular manual does not have nutritional breakdown for algae since it is not used commercially in Greece to feed chickens but I can tell you that I doubt that it can meet the varying requirements of the animals all the time on its own. You will need to put several other fodder sources just to meet the nutritional requirements of the animals. Furthermore commercial farmers do not actually keep their own reproductive flocks: there are specialized companies (very often strongly allied or downright owned by the chicken brands you buy at the super market) which keep reproductive flocks and sell to the farmers high yield (either in meat or eggs) chicken hybrids hatchlings which they sell to the farmers who feed them until they reach the proper stage for slaughter or when their egg production drops. Keeping these flocks is a major investment in intellectual property and in care for the animals. Unlike plants which can self reproduce without a drop in yield, animals require significant genetic diversity or yield (in both meat and eggs) starts dropping too rapidly from incest. On top of that lies the issues of what to do with poultry litter etc, keeping the animal at a much narrower temperature range than people etc.

I will be honest, my experience with aquaculture is far more limited, but I would not be surprised if there are also similar issues of nutritional balance of the feed mixture and genetic diversity. Also a high yield chicken hybrid is ready to eat 6-8 weeks after hatching. The gilt head beam (typical aquaculture fish in Greece) requires 14 months until it is ready for the market.

Let's ignore for the moment the issues with transporting the animals to Mars, if we can get people we can get animals. The high feed conversion ratio we get in commercial farms on earth is unrealistic on Mars, due to both to our inability to immediately (i.e. within a few years) produce an optimum feed mixture and our inability to keep a large genetically diverse reproductive stock. My educated guess would be that we can get a sustained feed conversion ratio of 3 or 4 to 1 until we can create the sort of infrastructure that exists on Earth, by which time though we will have cities on Mars. While people can be far more picky than animals in their feed even with a far primary higher energy conversion ratio for animals than with human food the feed to meat conversion ratio brings the whole food ratio lower than growing crops.

We will not need to breakdown organic nutrient to inorganic forms to used them as fertilizer. Far from it, plants assimilate organic nutrients better than inorganic sources. The main issue lies with the element ratios in manure compare to what plants need. In the Chesapeake Bay watershed the principal way to economically grow crops is with the free manure of the Concentrated Animal Feeding Operations. Farmers than use inorganic nutrient cannot compete with Midwestern farmers. Problem is that using the manure at the proper N ratio overfertilizes P, which leads to excessive P runoff and the Chesapeake Bay turning to muck. Obviously we wont be having this issue on Mars anytime soon, but we will still need to manage the nutrients in the output.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 12/31/2015 04:48 PM
We don't need to get the fish to Mars. We can take the eggs, which I would guess can be chilled to not hatch. (http://www.backyardchickens.com/t/690585/how-do-you-store-fertile-eggs-prior-to-using-an-incubator it seems chicken eggs can only be delayed by 10 days - enough for launch and Earth departure).

For fish at least, that could solve the problem of genetic diversity.

For warm blooded chickens, keeping them at optimum temperature will reduce the feed ratio.

I think for Tilipia, the optimum feed stock is algae. For chicken, we might lose out a bit.

Quote
We will not need to breakdown organic nutrient to inorganic forms to used them as fertilizer. Far from it, plants assimilate organic nutrients better than inorganic sources.

We really want to limit plants to where necessary, as they are inefficient. So only a proportion of the waste goes to plants - most goes to the algae.

Also, do the plants assimilate organics or do soil organisms help here? i.e in hydroponics, does this still hold.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 12/31/2015 05:41 PM
Furthermore commercial farmers do not actually keep their own reproductive flocks: there are specialized companies (very often strongly allied or downright owned by the chicken brands you buy at the super market) which keep reproductive flocks and sell to the farmers high yield (either in meat or eggs) chicken hybrids hatchlings which they sell to the farmers who feed them until they reach the proper stage for slaughter or when their egg production drops. Keeping these flocks is a major investment in intellectual property and in care for the animals. Unlike plants which can self reproduce without a drop in yield, animals require significant genetic diversity or yield (in both meat and eggs) starts dropping too rapidly from incest.

Actually I was aware of that practice, I saw an - to me -  astounding documentary on it. I was not aware of the scale of the advantage that practice gives though.

It shows once again what I have argued in other threads on other topics. People are not aware how complex our technical society is and how difficult it is to transplant it to another planet.

I do believe though that it will be possible to provide optimal nutrition with a number of algae types and protein produced in bioreactors from a number of specialized bacteria and funghi. I believe that our abilities in that field will increase dramatically in the next few decades. It may be actually easier on Mars where the flow of nutrients will be under total control unlike on earth.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 12/31/2015 05:42 PM
I am not an expert in transporting animals or fish but my feeling is that we would likely need to transport entire leaving animals rather than just sperm and eggs. I am under the impression that while transporting living fish eggs is pretty common, we simply do not know how the interplanetary environment will affect their vitality until they reach Mars. In several of the articles I have linked to over the last few months experts expressed their reservations if transporting viable plant seeds was possible under current conditions or if they would become sterile under the radiation. Also I am under the impression that the available space on the transport ship to Mars will be more limited than on the future Mars colony.

I am sure that we can reduce the feed ratio but optimizing the environment. For chickens that would mean keeping the same temperature all day which depends where in the growth cycle they lie, having constant aeration and removing the odor for the human's comfort etc. Much as plants are inefficient compared to algae in growth rate, an animal feed based system is less efficient overall than a plant based system. This does not mean that I am against placing animals on Mars, far from it, they can covert several inedible food sources to human edible food. Basing it though primarily on animals introduces too much risk. What happens if a disease breaks out and kills 75% of the animals? You will not eat the diseased dead animals for it might transmit the disease to humans and you are left with only 25% of the animals to maturity, which by the end might have consumed 4 times the feed per animal unit.

I am all in favor of turning algae into flour assuming that does not require specialized complex equipment that you would need to bring from Earth. You will need though a more traditional greenhouse style growth chamber for non algae plant species. The first colonists, when the number is below 10, might get away with a closed room with artificial lighting. In the long term though I am under the impression (and yes I am biased by my professional experience) that a clear structure is necessary.

In terms of physiology plants actually assimilate the nutrients directly in organic form. The soil biota will convert the NH3 and NO3 into more complex organic forms that the plants then assimilate. The hydroponic substrate environment is not devoid of microbes. Generally we do not use organic fertilizer (as in manure) on the liquid nutrient mixture, but this is because it is more expensive than inorganic fertilizer, not because plants will not assimilate it.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 12/31/2015 05:48 PM

It shows once again what I have argued in other threads on other topics. People are not aware how complex our technical society is and how difficult it is to transplant it to another planet.

I do believe though that it will be possible to provide optimal nutrition with a number of algae types and protein produced in bioreactors from a number of specialized bacteria and funghi. I believe that our abilities in that field will increase dramatically in the next few decades. It may be actually easier on Mars where the flow of nutrients will be under total control unlike on earth.

The Martian system will be high tech but the low possibility of external technical inputs means that it will look more like the sort of self contained agriculture that is typical of poor countries or isolated monasteries. For those that are not practitioners of agriculture one way or another the complexity of what high yield modern agriculture entails is indeed shocking. On your typical Greek field the seed is imported, machinery is imported, fertilizer is made locally but from imported petroleum, the farm worker is often an immigrant and in the end the only thing Greek is the water, the sun and the farmer who acts more as a manager than a manual laborer.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 01/01/2016 03:13 AM
According to: https://en.wikipedia.org/wiki/Photosynthetic_efficiency, Algae are at least an order of magnitude more efficient than crops at converting sunlight into glucose.
If Tilipia and chickens can then convert that into animal protein at 50% efficiency, then Tilipia and Chicken are at least 5 times more efficient than crops.

Another advantage of this system is that the growth rates are continuous. (Ie, no seasonal burst from planting to harvest.) That means your CO2 scrubbing and O2 production will be constant. As is your harvest.

Aside:
What is the highest CO2 levels that any plant or algae can grow at?

From a quick search, it doesn't look like plants can handle very high CO2 levels before acidification causes issues. That means you need the bulk of the atmosphere to be a buffer gas. Hence if the O2 is excess to needs, you need to vent it to prevent fires. Separating O2 from the buffer gas (probably N2) is energy costly.

OTOH, it seems to me that adding pure CO2 from the Martian atmosphere to a water-based system (algae), then collecting and venting O2 produced, is relatively simple. The water is the "buffer gas", you just add as much CO2 as the algae need, let the excess O2 bubble out and vent as necessary. (As long as you're not adding more CO2 than the algae need, you aren't acidifying the water.)

Since you can use the raw atmosphere, that lets you expand production as fast as you can ISRU manufacture your grow-pipes.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/01/2016 09:48 AM
If you have a closed cycle ecology there is no excess oxygen. All plant matter will be processed, even if not used for humans or animals. Excess oxygen will happen only if not all organic matter is in the cycle. Only if you dump plant matter you need to dump oxygen as well.
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 01/01/2016 07:28 PM
I think insects need to be considered as a source of animal protein. They are much more efficient than fish or birds; need far less space and husbandry, and populations can recover quickly in case of accident. And insects such as meal worms can be made into flour.

Cultural acceptability may be an issue; but that can be dealt with in the early days by not choosing the squeamish!
Title: Re: Scaling Agriculture on Mars
Post by: A_M_Swallow on 01/01/2016 08:37 PM
Agree about the nitrogen - and it's often raised as an issue for building very large colonies. However, Mars' atmosphere is 2.7% Nitrogen, and I think there will be a lot of atmospheric scooping to get CO2 for rocket fuel.
(Also a lot of Argon - for breathing, is Argon as good as Nitrogen?)

Some of the human body's process use nitrogen but we tend to get that from food rather than by breathing it. The algae may need it.

Argon can be used as propellant by Solar Electric spacecraft.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/02/2016 12:36 AM
Another advantage of this system is that the growth rates are continuous. (Ie, no seasonal burst from planting to harvest.) That means your CO2 scrubbing and O2 production will be constant. As is your harvest.

The CO2 buffer in a habitat able to feed its occupants is such that you will need to pump CO2 constantly, irrespective of the crop grown. The seasonal bursts are not as large as the daily bursts which depend on the radiation flows. In any case I am suggesting we grow horticultural plants that constantly set and produce fruit such as tomatoes and cucumbers, not once through and die plants like most field crops. Read the entire thread, it has been discussed already

Quote
Aside:
What is the highest CO2 levels that any plant or algae can grow at?

From a quick search, it doesn't look like plants can handle very high CO2 levels before acidification causes issues. That means you need the bulk of the atmosphere to be a buffer gas. Hence if the O2 is excess to needs, you need to vent it to prevent fires. Separating O2 from the buffer gas (probably N2) is energy costly.

OTOH, it seems to me that adding pure CO2 from the Martian atmosphere to a water-based system (algae), then collecting and venting O2 produced, is relatively simple. The water is the "buffer gas", you just add as much CO2 as the algae need, let the excess O2 bubble out and vent as necessary. (As long as you're not adding more CO2 than the algae need, you aren't acidifying the water.)

Since you can use the raw atmosphere, that lets you expand production as fast as you can ISRU manufacture your grow-pipes.

Again read the entire thread. We have already discussed this: Some algae species can survive as high as 80% CO2 though optimum growth rate is far lower. I proposed several pages ago that in the first phase we put in mostly Martian air and let the algae grow until the CO2 concentration drops to levels that higher plants can support. Then we keep the algae but we also have higher plants for their fruits.

If you have a closed cycle ecology there is no excess oxygen. All plant matter will be processed, even if not used for humans or animals. Excess oxygen will happen only if not all organic matter is in the cycle. Only if you dump plant matter you need to dump oxygen as well.

The system will never be fully closed and even if it is it will be on a cycle where the plant material will have more carbon than what is in the atmospheric CO2. Unless we start burning the plant remnants as soon as we harvest the crop (and we don't want that, the plant stems make good animal feed and prime material for mushrooms) CO2 will need to pumped in from the Martian air at times. Even if we do burn everything we will still have the organic ash which is carbon.

I think insects need to be considered as a source of animal protein. They are much more efficient than fish or birds; need far less space and husbandry, and populations can recover quickly in case of accident. And insects such as meal worms can be made into flour.

Cultural acceptability may be an issue; but that can be dealt with in the early days by not choosing the squeamish!

I am inclined to agree, though for cultural reasons I would prefer snails to insects

Agree about the nitrogen - and it's often raised as an issue for building very large colonies. However, Mars' atmosphere is 2.7% Nitrogen, and I think there will be a lot of atmospheric scooping to get CO2 for rocket fuel.
(Also a lot of Argon - for breathing, is Argon as good as Nitrogen?)

Some of the human body's process use nitrogen but we tend to get that from food rather than by breathing it. The algae may need it.

Argon can be used as propellant by Solar Electric spacecraft.

Nitrogen = proteins. The human body will eventually get rid to 80% of the nitrogen it gets from eating, we are not that good digesters. Algae definitely need the nitrogen, I am not sure though how good they are at fixing atmospheric nitrogen. Higher plants are not able to fix atmospheric nitrogen, soybeans and other beans simply are symbiotic with fungus that does the fixing and thus do not require N fertilizer, though they still need P and K fertilizer.

I am totally in favor of a system that feeds some of the food to animals, whether chickens, fish, snails or even insects, especially the kind that is unpalatable to humans. I am against a system that REQUIRES most nutrition to come from animals which we feed plant or algae based food. Depending on their growth phase their nutritional requirements differ, animals are bad metabolists and this introduces all sort of risks. One that I have not mentioned before is the need for veterinary support: Even if we do not feed the animals subtherapeutic doses of drugs as is typical in high efficiency high end animal production (and IMO it is best that we do not) animal farms on earth have the support of veterinarians and an entire industry that caters to animal health. Let's say that our animals get sick. Where will the drugs to cure them come from? Will we bring an entire organic synthesis infrastructure to Mars for the drugs? Where will its prime materials come from? On Earth very often it comes from biological sources, such as plants, aspirin is not synthesized out of thin air. What if the animals require therapeutic vaccination? Where will the vaccine come from? Even under optimum conditions anything from Earth will take six months, the animal might be dead by then. Do we carry from the beginning vaccines for every possible disease that the animal can get? They have expiration dates and we will need to send new ones on every resupply mission the colony gets. Granted some of these problems are also inherent with human health issues, let us not increase risk of failure by having a mandatory step to convert to animal protein.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/02/2016 02:47 AM
Chickens can be taken to Mars as eggs, thus not taking along the diseases.  Fish also.  If humans are clean and are screened before leaving, the eggs can be taken also and hatched on Mars.  This should eliminate most disease.  It may be accidently brought in later as the colony expands, but so can vets and drugs.  Man needs palatable protein. 

Too much plant protein over time might make some people allergic to the plants.  I was once not allergic to anything, but now I am allergic to soy, wheat, tomatoes, peanuts, and cows milk.  Go figure.  I did during my life love soy products, breads, tomato products, peanuts and peanut butter, and I had a glass of milk every morning for breakfast and ate textured soy protein flavored as chicken or hamburger.  Now I've had to change it all.  I have to drink almond milk, eat almond butter, avoid tomatoes and soy products, and very little bread.  I've never gotten allergic to any animal protein, thank goodness. 

The more variety of food, the healthier the people will be.  Martian agriculture will take up a lot of time and space to feed thousands.  Tilapia can be processed to taste like crab or other seafood.  Chickens can be process any number of ways, even made into fake hamburger.  Algae may be able to be processed into fake meat, but I haven't heard of it being done like soybeans.  I can grow enough green beans (string beans) in a space of about 6'x12' in my garden to feed my wife and I for a year about once a week.  There are a lot of garden vegetables that can be grown in a small space that are highly productive.  Rabbits are actually better meat producers than chicken, but chickens give eggs.  Over time it might be a trade off.   
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/02/2016 05:28 AM
I am against a system that REQUIRES most nutrition to come from animals which we feed plant or algae based food. Depending on their growth phase their nutritional requirements differ, animals are bad metabolists and this introduces all sort of risks.

I don't think REQUIRES is the right word. It was pointed out that using animals may yield cheaper calories than growing higher plants thanks to the conversion efficiency of algae and protein from methane. You are very right about the different requirements in animal feed. I believe those requirements can be met using a mix of algae and methane protein.

No doubt that direct use of algae will yield still higher efficiency for cooking oil and carbohydrates. But they require complex food technology to transform them into palatable food, not just a means to survive. A colony needs to offer a variety of palatable foods to attract settlers.

One that I have not mentioned before is the need for veterinary support: Even if we do not feed the animals subtherapeutic doses of drugs as is typical in high efficiency high end animal production (and IMO it is best that we do not) animal farms on earth have the support of veterinarians and an entire industry that caters to animal health.

Very true. However isolated flocks and reduced risk of infections should make such medication unnecessary without affecting yields too much.

For those unaware of how poultry is produced I give a short recap because it is really relevant.

Aegean Blue please correct if I got something wrong.

What I saw was related to egg production. The numbers I use are from memory but are in the ballpark. There are just 3 to 5 breeders worldwide that provide 80% of all breeding stock for egg production. It works like this: The breeder ships young chicks to producers worldwide. One shipped chick can produce 200-300 eggs that are hatched. Those chicks are then used for egg production. Which means ~50,000 eggs from one shipped chick. With that this line is abandoned and fresh chicks from the breeder are purchased to avoid drop of efficiency.

Depending on local preferences the chicks can be optimized for only eggs. The chicks would be used for animal feed only. In other countries the chicks are still sold for cooking and therefore are bigger. For that a different breed is provided. Chicken raised for for meat, not eggs, would be another breed again.

If eggs can be sent to Mars the method could be used there too.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/02/2016 10:02 AM
I think insects need to be considered as a source of animal protein. They are much more efficient than fish or birds; need far less space and husbandry, and populations can recover quickly in case of accident. And insects such as meal worms can be made into flour.

Cultural acceptability may be an issue; but that can be dealt with in the early days by not choosing the squeamish!
I see quite a few stories on this, but reckon that Tilipia is just as efficient as insects. The key is in not wasting energy to maintain a warm body.

However, Tilipia eat algae. I assume not all insects do.

Reading this thread, it reinforces my conclusion that algae will be the primary "base" food for the colony.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/02/2016 10:12 AM
I see quite a few stories on this, but reckon that Tilipia is just as efficient as insects. The key is in not wasting energy to maintain a warm body.

However, Tilipia eat algae. I assume not all insects do.

Plant eating insects will probably eat algae pellets or flakes. That needs filtering them out and drying. Tilapia will do the filtering themselves.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/03/2016 02:06 AM
The weird part about animals is that if we grow them in a completely hygienic environment, no diseases no nothing, they actually grow worse than if we grow them in an environment that has some germs. I am not just talking about ruminants which cannot survive without the microbes in their first two stomachs, I am also talking about single stomach animals. The epidemic in allergies in the developed world is at least partially due to the very hygienic environment it has become: when the immune system does not have an enemy to fight it overreacts to allergens. The Martian colony is going to be very clean environment, there will be issues with PM2.5 and PM10 from the dust but otherwise we should not anything attacking us or animals, for all the good or bad this means.

In terms of chickens indeed there are very few breeding companies that produce two types of hybrids: Meat producing and Egg producing. For meat producing they sell to the 2nd order producer roosters and hens at breeding ratios (more females than males) of somewhat different genome which produce the egg. The final producers orders say 100 chickens for the next flock. The second order producer gives him 100 chickens irrespective of sex (out of ~110 eggs incubated, not all hatch) and then the 100 hatchlings are fed until the survivors (not all survive) make it to commercial weight.

If we are talking about egg laying hybrids the second order producer will incubate something like 220 eggs and give the final producer only the females. The 100 live males will make it to the children's live chicken market if they are lucky, otherwise they will be killed on the spot because it is not economic to fatten them. The 100 females will start producing @ 1 egg per day (roosters are necessary only to fertilize the egg, not to produce it) for the next several months. I do not remember if it is 9 or 15 months (its been too long since that class) but at that point the hens start changing their feathers which does not affect their ability to produce eggs but makes them require more feed per egg than their younger self. So instead of ruing the feed ratio and the economics of the farm they are sent to the slaughterhouse and are replaced with a new flock.

I think that we need to recognize that there will be at least three very different farm model stages depending on the colony status, what I would roughly call the 4 person colony stage, the 40 person stage and the 400 person stage. At the 4 person stage (4 because that is how many the Orion fits and how many are in the MarsOne stage 1) the colonists will mostly eat Earth packed food with the addition of small stuff like MELISSA and Veggie while they set up the colony. There will be a closed growth room with artificial light etc but it will not provide the bulk of the calories. At the 40 person stage there will be light tubes with algae and a greenhouse receiving sunlight and supplementary illumination along with supporting structures such as a lightless mushroom room which will provide food mostly from plant sources, in addition perhaps to sporadic animal meat both local and of earth origin. At the 400 person stage there will be animal breeding and growing facilities though I doubt that they will provide the bulk of the calories, it is more spatially and energetically efficient to bring them from plants
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/03/2016 09:08 AM
The weird part about animals is that if we grow them in a completely hygienic environment, no diseases no nothing, they actually grow worse than if we grow them in an environment that has some germs. I am not just talking about ruminants which cannot survive without the microbes in their first two stomachs, I am also talking about single stomach animals. The epidemic in allergies in the developed world is at least partially due to the very hygienic environment it has become: when the immune system does not have an enemy to fight it overreacts to allergens. The Martian colony is going to be very clean environment, there will be issues with PM2.5 and PM10 from the dust but otherwise we should not anything attacking us or animals, for all the good or bad this means.

 :( With my personal history of allergies I am unfortunately fully aware of this. Though I was raised in a semi agricultural environment and should not have acquired that problem.

I was not thinking of raising animals sterile. But it should be much easier on Mars than on earth to eliminate those germs that cause use of medication on earth. The same should apply to both humans and animals. Don't go for a sterile environment, keep the immune system busy. We are learning what to do presently.

Sidenote: I have heard they increase the yield of eggs to more than one a day by artificially introducing shorter days.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/03/2016 05:53 PM
It takes 20 hours to form one egg. From the moment the yolk is formed it takes 20 hours down the birth canal to form the egg white and the shell. To the best of my knowledge chicken farms do not have a day night cycle, it is always day under artificial. If there was a way to dramatically shorten the 20 hours, we could have more than 1 egg per day
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/03/2016 06:13 PM
I for one, even if I was 25 and perfectly healthy, would not go to Mars without a variety of food and especially protein.  Living on Mars is a long time unless rotated out like the military.  They will need chickens, they will need eggs, they will need fish, at least that much.  Small breeds of goats or cattle will eventually be taken.  Like I said, over time, some people can become allergic to certain plant proteins and must begin to avoid them.  One could die without a variety of nutrition.  Various beans and nuts would help.  Some however come from trees.  We have an epidemic of type II diabetes in America due to dependence on too many carbs and not enough protein and fat for balance.  In India, they do eat eggs and fish. 

I do agree algae can be a base food stock.  Mainly to feed fish and pelletize to feed chickens, and maybe to make cooking oils.  A huge variety of vegetables can be grown in very little space, especially year round inside Martian greenhouses.  Tilipia, chickens, and rabbits also take very little space.  Even small breeds of swine take very little space and can eat all the plant waste, as well as waste from processing fish, chickens and rabbits.  Animal wastes provides the fertilizer for algae, as well as the plants.  I would say farming on Mars will take up about 10 times the space that living quarters will take up, not including manufacturing which will have to be done to process the Martian metals and make rocket fuel.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/04/2016 01:17 AM
I am not against having animal proteins in Mars, far from it. I am skeptical on what point should this new level of complexity be introduced into the farming system. Yes, agriculture on Mars has the potential to take far more space than any other activity, even if using multilevel high intensity hydroponics. Adding animals to the mix, beyond the whole range of issues uniquely associated with animals such as hygiene, genetic diversity and veterinary support means more growth area for the food for the animals. In the first phases it is better to ship corned beef from Earth once every couple of years. The proper mix between different food sources ought to be decided by nutritionists, agronomists and engineers together. In this thread we are simply throwing ideas for 30+ years down the line, no need to get heated up over something that some of us will not even be alive when it happens.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 01/04/2016 02:32 AM
About developing allergies:

You don't need to shape your plan around it (beyond obviously avoiding foods that commonly cause allergies) because food will probably come from earth for a good long while and gradually taper off until they become more like medical suppliments for certain individuals. It is just like medical insurance. Rare expensive conditions can be covered within some statistical limit and no one needs to go out the airlock ;)

I always find reading this thread a little depressing. There are lots of good suggestions but when does the talk end? There is almost no hurdle to actually doing as there is for say spin gravity or BEO radiation mitigation. IMO There is such vast research on nutrition and agriculture that the main problem is seeing the holes in it. What this subject needs is a tiny $100m/y budget to condense all that research down to a few intensive farming trials that at any moment are our best candidate to actually put on mars. I mean, the requirements are so basic you could possibly end up making a fair bit back selling your produce! If the HSF budget was actually about space settlement and not about justifying launch architectures we would have a few decades confidence in something specific by now.

I realise there are various things people can point to that mention relevance to space. I mean that by now we should have three candidates say A, B and C, and whenever someone throws out a new leftfield idea, they are really talking about whether it can be shoehorned into one of the above. Often it sounds like people are proposing first shipping a hundred colonists to mars and then experimenting with only feeding them cicada wings or something.  :P

Actually I wonder if a commercial company could do this and fund itself just by the novelty value of selling durable healthy food with a Mars logo. IMO that is vastly better than the Mars One business plan right there!

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/04/2016 03:44 AM
I agree that it is depressing a bit but also escapist to think about agriculture to Mars. For one thing I propose we ship an entire greenhouse along with the first mission to Mars. I even tried to calculate the greenhouse's weight earlier, though I was pointed to me that we need to make it into a pressure vessel. High end food from Mars to Earth like the EU Protected Geographical Status? Why not, but you need actual farmers to farm them. No robot built yet is fully able to do agriculture, otherwise they would have replaced unskilled farm labor years ago, starting in California.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 01/04/2016 05:15 AM
High end food from Mars to Earth like the EU Protected Geographical Status? Why not, but you need actual farmers to farm them.
Oh, to clarify by mars label I didn't actually mean food from mars, but for mars or from a trial greenhouse for mars.

For some fraction of the experiment you might have to keep the humans you fed it to in the mix also of course but I can think of all sorts of side cases where produce could be sold.*

What would make this more than just any old greenhouse with a mars logo slapped on it is if it was satisfying requirements to actually be included in a SpaceX architecture, or similar. You need some clear distinction between outright con, abstract research and work on something usable.

Probably simpler to just imagine NASA paying a tiny fraction of its budget for this. Though as Han Solo put it, we can imagine quite a lot.

*(edit) here is a good example: I don't think you absolutely NEED to think of these greenhouses as enclosed environments with humans though largely they would be. Another worthy criteria is as an engine to turn mars regolith and atmosphere into potatoes etc. Doing so likely would involve a cycle that lasts multiple years but notice there is not actual human biology in the equation, so it would be legitimate to input some "mars soil simulant" and sell any produce you care to remove.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/04/2016 06:44 AM
Look at this NASA video. A greenhouse is part of the present concept for a Mars base.

http://www.youtube.com/watch?v=94bIW7e1Otg

It's at 5:40 if you don't want to watch through it all.

I am sure it is in the plans for the first flight of SpaceX too. These would not be to provide full nutrition but much needed supplements of fresh produce. After all the present Mars plans of NASA in the 2930ies call for a 500 day stay on Mars.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 01/04/2016 07:56 AM
I think almost every plan for a base I have ever seen includes something like a greenhouse. I bet if we dig through whitepapers for VSE they mentioned superb closed cycle life support and growing greens at some point.

The problem is the same as with happened with VSE. I mean, the entire base was dropped and then the lander suspended indefinitely, so that just takes the whole example to an absurd level, but I can guarantee that unless NASA was given a glut of money that allowed them to actually achieve moon or mars missions.. and was then given a glut of money on top of that and told to take their time, then the greenhouse would be the first thing that would be dropped.

I mean, there might be some experiments that end up in their diet, but it would just be garnish on top of the most reliable LS they could find and preserved food for calories.

Goal number one would be safety for the crew.
Goal number two would be doing things that really can't be done on earth, such as science.

I would actually agree with their logic.. of course the first thing you do when you finally get to mars will not be to do what you might as well have done on on earth.. but I am saying we should do it right now on earth, get it to a really high degree of technological readiness. I am not talking garnish but a life support system as close to eternal as we can manage. We should have been doing this since apollo, during the hiatus with the shuttle, kept working cheaply away at this during the fiasco that was constellation, and while arguing what SLS is for. Even if such a project was given the years of preparation necessary to go on the first mission to Mar we would still of course send enough preserved food to last till the next mission though.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/04/2016 01:14 PM
Well, for one thing we do not have a sample of Martian regolith. The Martian landers have been having ever better analytical tools so we have some idea how to make a decent analog, but simply put we do not have a sample that we can do all sorts of analysis with. Then again would we really want to do hydraulic conductivity tests with actual Martian samples? Do we want to sacrifice even 100 g of Martian sample to measure water flow rates?

In terms of technological maturity hydroponics are at TRL 9. I doubt that the difference in gravity would have a serious effects on hydraulic properties. I did propose earlier that we use rockwool or cocopeat before Martian regolith because exactly we have excellent knowledge of both materials. The unknowns with a Mars Greenhouse have more to do with how the plants survive and produce under Martian surface radiation, and while there have been a few experiments on Earth, we cannot really know how the actual mix of radiation sources on Mars effect plants until we try it. For animals indeed there are bigger unknowns, fish are suspended in the water but how would gravity affect tissue growth of land animals?

I would agree that a Mars logo on food would make a great curio for the NASP gift shop. We could put Mars carrot sticks next to the astronaut ice cream, which somehow sells despite being by all accounts pretty horrible.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 01/04/2016 01:40 PM
Lack of good specifications on martian regolith is also a huge flaw.. if current activities were assumed to be motivated by the goal of space settlement.

If my goal were to master space settlement priorities would be
(A) mastering self sufficiency in a smaller package than the entire earth. A fair chunk of that is about growing food.
(B) precursor missions that feed back necessary information into A

The fact we havent done A or B is just because this has never really been a goal.

This is just me griping though. A suggestion specific to this thread is that instead of discussing techniques (which seem to me successively more arcane) you guys could discuss criteria for success. Ie what actually has to be demonstrated before anything discussed here is included in an actual mission.

IMO it goes beyond theory. Pick any suggestion off this thread. I think it would have to be selected and funded and demonstrated on earth - I mean the actual payload in full detail, and in a multiyear project - before it earned its place on a HSF mars mission. There are a million suggestions. What may matter more is how to thin them down to a working demonstrated solution someone would trust to include in a multibillion dollar goal.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/05/2016 07:49 PM
I don't know where you get 20 hours for a chicken to produce and egg.  Most chicken farms I know of locally get the hens to lay 2 eggs per day.  They lay one during the day and they turn on lights at say midnight for a couple of hours to confuse the chickens and they lay another one.  Once they quit laying two eggs per day, they send them to the processors.  A good layer will do this for about 2-3 years. 

Also if one develops an allergy from algae, on Mars they are screwed unless other foods are available. 

In China chickens are raised over catfish ponds.  Chickens only process 50% of their food intake.  Catfish eat the chicken waste.  At Auburn University, they take chicken waste, dehydrate it, and mix in molasses and feed it to cows.  So, more efficient means of animal utilization are being developed.  Chicken manure also makes some of the best plant fertilizer available.  My grandfather raised chickens and gardens with no chemical fertilizers.  Rabbits are good food sources also.

Speaking of insects. Bees will one day have to be taken to Mars to pollinate plants taken, especially fruit and nut trees.  Something like 70% our food plants need bee pollination.  Also, if you try to have algae only for food, how much power is it going to take to dry it, and process it into palatable food?  It might be more energy efficient to raise tilapia in a 5' x 8' tank for a family of 4 for fish once a week.  That is not much space.  I have said a lot of variety of food can be grown in a small space, including animals and fish, with the exception of grain crops. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/05/2016 08:30 PM
If my goal were to master space settlement priorities would be
(A) mastering self sufficiency in a smaller package than the entire earth. A fair chunk of that is about growing food.
(B) precursor missions that feed back necessary information into A

The fact we havent done A or B is just because this has never really been a goal.

I guess you underestimate what is already being done. A lot of general agricultural research is appliccable on Mars. There has been research on how much, or better, how little atmosphere is needed to give plants healthy growth. It's quite low and they were optimistic they can go even a lot lower with adapted plants. The limit was not actual partial pressure needed but wrong response by plants. They went into a drought modus even when saturated with humidity. There was optimism the problem can be overcome and plants grow as long as water is liquid under the temperatures needed for bioactivity.

Once there is an attempt to design a martian greenhouse that design will need testing. Probably there will be a number of designs. Some, like me, assume mostly ambient lighting, maybe enhanced by mirrors. Some assume all artificial lighting, like in that NASA video I linked. I am sure there is plenty of data on how much light is needed for plant growth.

I think the highest demand for light will be with plants for staple food that produce a lot of calories. But I don't see those plants used much on Mars. Bulk calories will come from algae. Algae growth researach is also ongoing. The university where my daughter studied (unrelated) had research on algae in pipes and with artificial light, but that's for reproducable results. I have seen it, very interesting. NASA is working on algae based biologic ECLSS.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 01/06/2016 05:26 AM
I guess you underestimate what is already being done. A lot of general agricultural research is appliccable on Mars. There has been research on how much, or better, how little atmosphere is needed to give plants healthy growth.
I don't think I have.. I have certainly heard of that research before. But as I said there is a huge body of agricultural research and Im not claiming to have a grasp on even a fraction. As I said before I suspect it is the holes we have trouble seeing amongst all that research. There is also a lot of research that may or may not be relevant to our actual first greenhouse on Mars. Growing in different pressures is a good example. Sounds useful. May or may not be used. Human issues may or may not make stepping between different pressures worth the bother. If it is not used initially it may well find a use later. No doubt it will pay for itself at some point.

It is possible I am actually overestimating the work that has been done, because what I am claiming is that we should have been working on candidates long before this point. These are the easy low cost things you should do before committing to a specific diameter for your rocket for example.

If you never start on candidates, you will always be ten years away from using it to solve important problems for your mission. You can still send greenhouses early, but you wouldn't really trust them. They would be 'research projects' that may add garnish next to your necessary calories but are mainly just mass and make-work that could have been done cheaper on earth or even in LEO. So they can't actually be used to allow you to build a smaller launcher for example. It is too late for the SLS specifications anyway, though given the time between Apollo and now it should not have been.

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/06/2016 01:07 PM
The 20 hrs figure actually comes from class, over a decade ago now. I would go back and look at my book, but unfortunately my book and notes are located on the other side of the Atlantic. Chicken manure has a salinity problem, it is not as good as cow manure. Now I am pretty sure that at Auburn they have several experiments running to help treat chicken manure, at Virginia Tech most experiments were over creating biochar with manure rather than feed. To be honest at the ASA meeting I tended to go to the Remote Sensing session rather than the organic material reutilisation sessions so I do not claim expertise beyond what my classmates were presenting at the department seminar.

I agree that quite a large part of the earth experience is applicable to the Mars experience. Much as growing food is critical for space colonization, practical experience in any space platform is mostly limited to biology experiments conducted mostly in Soviet/Russian space stations. Agriculture in space requires too much room for something beyond a general experimental apparatus such as ISS Veggie. Even a pilot module is too big so far.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/06/2016 07:48 PM
Speaking of Mars studies, I remember reading a paper in Acta Horticulturae in my undergrad days about work on making a space hydroponics system at JSC. Acta Hort. issues are actually conference proceedings after editing. I do not remember NASA presentations at the ASA/CSSA/SSSA conferences I attended dealing with agriculture in space though granted that conference is so massive I could have easily missed them. If people presented at the ASA in the last 5 years at least there would be online video of their presentations. So far several documents were shared of previous research on this thread, does anyone know of video/audio of conference presentations on the topic of space agriculture in general?
Title: Re: Scaling Agriculture on Mars
Post by: Distorted Humor on 01/06/2016 08:12 PM
Okay, be nice, first post here with a lot of smart people.

It would make sense that agriculture would use a varied techniques to make sure the colony/mission was not dependent on one method. 

For example just me podering

Crew arrives, and has a large amount of shipped food to eat while the food systems come online.

have a algae system to process sunlight (By direct sunlight or PV -> light) and Carbon dioxide. Process the algae into sugars and biomass.   The Biomass would then be used for fish or to be mixed with the human waste produced by the pre-packaged foods to start small greenhouses.

The sugars would be used to grow mycoprotein that is then goes though the heat treatments and processing to provide one source of Mars food.   

The human waste mixed with martian soil will be begin to start greenhouses (I will let the engineers figure out the best way to get sunlight to the plants, be it direct or though some sort of lighting system) at first the crops grown would be for moral boosting flavor and simple high calorie plants that do not require pollination (Potatoes come to mind) as there is increasing biomass from the mars mission it can be used to make more greenhouses, thus increasing the ability for the Mars base to be self sufficient.

On a moon base I am not sure there would be enough carbon dioxide produced to provide for both greenhouses and a algae system, but on mars that solves itself due to it being readily available by air pump. 

Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/07/2016 03:10 PM
First of all, read the entire thread. I would like to comment that unless you are in a Mark Watney type situation as a principle you do not use human waste without treatment. Even Watney needed the waste for the Nitrogen, not the organics. It would be better to start agriculture with an artificial substrate such as rockwool and cocopeat before composting the plant stems with human waste to create compost. We have discussed this in detail here, read the previous pages
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 01/09/2016 04:24 PM
It would make sense that agriculture would use a varied techniques to make sure the colony/mission was not dependent on one method. 
...
Crew arrives, and has a large amount of shipped food to eat while the food systems come online.

I agree with both those statements.

Crew safety demands that the first crews have sufficient food reserves with them to last until either the next vehicle arrival or they depart from Mars (including the journey back to Earth). This will be true until food production on Mars has been proven and robust.

That said, even the first mission will have some food production envisaged. Any food produced will reduce usage of that brought from Earth, which means the next cargo ship/crew won't have to bring as much and can substitute other cargo instead.

The early missions will have experimental food production covering a number of different proposals. We might think we know what will work on Mars, but nothing beats actually attempting to grow food on Mars to find out if we're right or not! Once we know what does and does not work, we can send larger units of production. It might be worth making a list of all the different early experiments that could be tried.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 01/10/2016 03:13 AM
AegeanBlue,
I have read the entire thread, and a few other older threads on the same or overlapping topics. That doesn't mean I've memorised them.

Crew safety demands that the first crews have sufficient food reserves with them to last until either the next vehicle arrival or they depart from Mars (including the journey back to Earth). This will be true until food production on Mars has been proven and robust.
(Emphasis mine.)

No. It will be true. Period.

You can never count on the current crop adding to your reserves. You must always have enough reserves to survive until your Earth-return window, plus the trip time back to Earth. You can never let your reserves drop below that, until you make the decision to abandon the site.

And if you don't want the default response to be to abandon your base, you also need enough reserves to get through at least one full failed growing season. Preferably one and a half. (One full lost season plus one poor season.)

I think people forget this. It's why we invented silos. Every isolated community must be able to survive flood or pestilence destroying their entire current crop, or a two or three year drought. While systems on Mars will have fewer natural disasters, they'll have mechanical issues that are equivalently severe. Seal failures, contamination, etc.

BTW, this rule applies to colonies as well. You must be able to survive a complete loss of your current crops, including the time it takes to fix the problem and grow a new crop through to harvest. And ideally, be able to survive a few bad seasons before you have to go onto starvation rations, and/or abandon the colony.

For Mars, you should also assume the disaster requires parts or a whole new module from Earth. So you'll need enough food reserves to survive however long it takes to send a replacement system (time to launch window, plus trip time, plus whatever margin is needed to prep the replacement for transport), plus the time to set it up on Mars and grow the next crops through to harvest, plus an allowance for that first crop to be a 50% failure (teething problems with the new kit.) And, of course, in case you still need to evacuate, you can never let your reserve get lower than the time to the next Earth-return window plus the trip time back to Earth.

Playing around with the numbers, I'd be surprised if you can get away with less than 3-4 years continuous reserve.

And of course it would be better to be able to survive two such failures. Say an irrepairably breached grow-module, plus the loss of the incoming supply mission carrying the new module. So around 5-6 years continuous reserve. (For the first mission, that reserve is on top of the time to reach Mars and establish the first crop.)

(This is actually worse than primitive communities in Earth's history. Even a stone-age village only needs about 18 months supply, depending on how conservative they are and how reliable their climate.)

For a single mission, that completely eliminates the mass-benefit from growing your own food, even if the food production technology is proven and trusted. It's the same for multiple mission if they are going to separate sites, one site each, a la Apollo.

If you have a permanently manned base, then future missions would eventually benefit from greenhouse/grow-modules, as you noted. But even then, the benefit is only from suitably stored supplies, not from current crops. You can only count proven supplies, not anticipated harvests. You must have a continuous storage system, no matter how much you trust the production system.

Ironically, one-mission-per-site ends up with a mass advantage over a base+greenhouse architecture, since they only needs enough reserves to get home, which they'll have anyway. It could take 6-10 missions before the base-architecture gains a mass advantage from growing food.

(Obviously, there is a psychological benefit from freshness/variety, even for a single mission. And the mass required to grow low-calorie salad crops is much less than a system to produce a full diet year after year. The bad news is that your salad hydro-module will be the first thing cut when funding or mass-budgets gets tight.)
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/10/2016 04:02 PM
I live in the deep south.  Don't know about the soil conditions elsewhere, but chicken manure is the best fertilizer here.  No seeds to sprout weeds.  Cow manure is full of seeds and if the manure isn't sterile, it can create havoc in a vegetable garden.  I can, in a 20' x 60' space grow ALL of my vegetables for my wife and I, and still give some away.  This isn't in a greenhouse either and is a very wide variety of vegetables.  So in a controlled Martian greenhouse or houses most all vegetables can be grown.  Some with a lot of protein like beans and peanuts.  I can see algae being used to feed fish and make pellets from dried and processed algae to feed chickens and rabbits.  To begin with beans, peanuts (unless allergic), chickens (eggs) and rabbits would produce a wide enough variety of protein along with the vegetables.  Now grains such as rice, wheat, and corn will take more greenhouse space, but can be dried and shipped from earth initially.  However it may be cheaper to build the greenhouse space to grow these also instead of shipping.  To me, building materials, and industrial manufacturing equipment would be more beneficial to ship from earth, and just make a lot of greenhouse space for food production. 
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 01/11/2016 12:31 AM
...I believe, I was the first on this forum to point that out.  :)...
I think I beat you to that, though I'm not sure. :) And it's ammonia, not nitrates, that you need for the single cell bacterial protein (in addition to the methane). http://calystanutrition.com/
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/11/2016 06:03 PM
Historically societies have kept about a year's reserve of food in the form of grain and other such food with a long life. If the crop failed a year or if there was a foreign invasion they could absorb one year, but not a second because of shelf life issues. Unfortunately food decomposes over time, there simply aren't that many foods that can last 3-4 years and those that can are often not very nutritious. Also there is the question of weight: according to Dr Google (who points to an NPR article that derives its data from USDA) each American eats 1 short ton of food per year. So for a 4 person colony and for 26 months between launch opportunities you would need ~ 8 metric tons of food if the colonists eat like Americans. The current designs talk about landing a 20-40 ton lander on Mars for the first trip. True, Americans are known to overeat and have a reputation of wastefulness but still, even with 500 kg per person a 40 person colony would require a cargo lander of 42 tons every 26 months just with food, let alone the spare parts and other supplies. Also we humans do not assimilate 100% of what we eat, the waste stream is going to be significant.

From what I see on the internet MarsOne has budgeted 800 kgs of food for the 4 people to eat in the Transfer Vehicle during the 210 days of transfer. According to Dr Google (pointing to a Space.com article) ISS astronauts get 1.7 kg/food per days which calculates to 620 kg/year. Also in Mars gravity astronauts would spend more calories than in microgravity. If anyone here has better food weight numbers please share them.

As for manure, there shouldn't be any seeds after it has been digested. You are not supposed to use it right out of the animals, you are supposed to expose it to the elements and mix it every week until digestion ends and after the mixing temperature no longer goes up. Undigested manure Nitrogen is unavailable and also parasites have not been killed before digestion. At least that is what we were told in class in Greece
Title: Re: Scaling Agriculture on Mars
Post by: Arb on 01/11/2016 07:04 PM
This thread is about scaling agriculture but if we're going to talk about rations delivered from earth then reliable sources :) reckon you can easily get down to 1Kg per person per day using 1950s technology, so possibly even less in 2016.

Quote
News groups: sci.space.science
From: [email protected] (Henry Spencer)
Subject: Re: Space Garden
Organisation: SP Systems, Toronto, Canada
Date: Mon, 14 Feb 2005 19:59:13 GMT

In article <[email protected]>,
Marc 182  <[email protected]> wrote:
>> The hurdle you run into right up front is that fairly trivially you can, using technology known since the 1950s, get all the supplies you need into about a kilo a day per person...
>
> What's life like living on a kilo a day? Baby food out of a tube?

Baby food and/or tube food is almost all water, the last thing you want for efficient packaging.

You'd eat freeze-dried or dehydrated food -- quite like what you'd eat on a backpacking trip, perhaps packaged a bit differently -- rehydrated with recycled water.  Uninspired, but reasonably varied and pleasant, menus.  Occasionally, as a break from routine, a bit of frozen whole food or a vegetable or two grown on board.  (It *is* worth growing a few plants, partly as a diversion and partly to add some variety, although they wouldn't be a major component of the diet.)



Been waiting a decade for a chance to use that  8)
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 01/11/2016 09:14 PM
Soylent is less than 500 grams per day. I drink it sometimes. A fat-biased version would require even less mass, say 300-400grams per person per day, including packaging.

You can do much better if you produce the macronutrients via something in a vat like algae or single celled protein. Complete nutrition doesn't have to require much mass.
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 01/12/2016 02:11 AM
I live in the deep south.  Don't know about the soil conditions elsewhere, but chicken manure is the best fertilizer here.  No seeds to sprout weeds.  Cow manure is full of seeds and if the manure isn't sterile, it can create havoc in a vegetable garden.  I can, in a 20' x 60' space grow ALL of my vegetables for my wife and I, and still give some away.  This isn't in a greenhouse either and is a very wide variety of vegetables.  So in a controlled Martian greenhouse or houses most all vegetables can be grown.  Some with a lot of protein like beans and peanuts.  I can see algae being used to feed fish and make pellets from dried and processed algae to feed chickens and rabbits.  To begin with beans, peanuts (unless allergic), chickens (eggs) and rabbits would produce a wide enough variety of protein along with the vegetables.  Now grains such as rice, wheat, and corn will take more greenhouse space, but can be dried and shipped from earth initially.  However it may be cheaper to build the greenhouse space to grow these also instead of shipping.  To me, building materials, and industrial manufacturing equipment would be more beneficial to ship from earth, and just make a lot of greenhouse space for food production. 

Having a variety of food sources is not only good for morale it reduces the change that a single disaster will wipe out your entire food supply.
Chickens BTW are pretty efficient at turning insect protein into something more palatable so them and the right insects can really help with recycling.
As for keeping a reserve for long term storage the best solution I think is to simply use cans as they can be easily manufactured with martian materials and are very robust.
For food shipped from Earth just use MREs and dehydrated food.
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 01/12/2016 03:42 AM
Chickens BTW are pretty efficient at turning insect protein into something more palatable so them and the right insects can really help with recycling.

Chickens are relatively efficient, so far as vertebrates go, at turning insect protein into some other package of protein, but nowhere near as efficient as eating the insects directly! As for palatability; that's mainly a psychological problem in Western societies - 80% of countries eat some insects in their diet (and 1,000 species of insects are eaten regularly). Even for Westerners, once you get over the hurdle of that first bite most people find them tasty enough (it helps if they don't have wings, legs and eyes at the point of consumption!).

My favourite suggestion at the moment is mealworms. They're easy to grow - lots of hobbyists do so at home to feed their reptile pets - and can be fed algae. I've tried them myself and they're rather nice in a chili! (Or stews, flans etc.) And you can turn them into flour to make biscuits and bread out of. And, after all, what's the real difference between a mealworm and a prawn?

And anyone who can't bring themselves to eat them? Well, they don't get to go!
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 01/12/2016 03:50 AM
Soylent is less than 500 grams per day. I drink it sometimes. A fat-biased version would require even less mass, say 300-400grams per person per day, including packaging.

You can do much better if you produce the macronutrients via something in a vat like algae or single celled protein. Complete nutrition doesn't have to require much mass.

Soylent is fine, but you wouldn't want it to be your only food. It's a little high on fat and protein, and only has half of the fiber needed. A low fiber diet is common, but not healthy long term. Probably okay for the trip to Mars. Use some other dehydrated food, maybe fruit and vegetables, to get the correct nutritional balance.

You also need some variety for morale, but the bulk of the food could be Soylent with different flavors added.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/12/2016 05:17 AM
You also need some variety for morale, but the bulk of the food could be Soylent with different flavors added.

I assume we are talking Mars mostly, not transfer. On Mars cooking meals would be easy with gravity. Dry goods like beans, lentils, dried vegetables and fruit, rice, noodles, flour for bread and pastries, sugar, cooking oil, egg powder, milk powder have very high caloric content and will allow to prepare a wide variety of meals. I can smell the fresh bread.
Title: Re: Scaling Agriculture on Mars
Post by: nadreck on 01/12/2016 05:45 PM
Having followed this thread for a long time there are a couple of issues I have some of the more rigid outlooks on things.  For a variety of reasons there needs to initially be supplies of food brought from Earth, rather than optimizing that food for nutrient/mass it should be optimized for utility in the nominal progression of ISRU development while still supporting the backup food supply needs for the maximum credible contingencies. As well rather than making complete self-sufficiency a medium term goal what is needed is a healthy excess in goods that can be grown locally, processed and packaged efficiently with 99.9% locally sourced material with the ability to send them off Mars as trade goods (the most obvious trade is sending MCTs back to LEO with supplies that could be 95% or more of the daily required mass for a reasonable and balanced diet for the next passengers coming to Mars).

While one long term goal of settling Mars is for it to be more than self sufficient (ie back up Earth that without Earth could go on to settle other worlds and grow and develop human society). The steps to get there should be the steps that are the most effective through the medium term of supplying more than needed of what can be easily supplied so that there is always margin in those items and finding the most utility in imported goods.

I would foresee initial food imports to be complete balanced meals for all the people there planned out to the point where the first crops are grown. Supplies for after that point would be planned around supplementing what was grown initially and brought in volume and variety to serve as emergency rations that are not as traditionally balanced but as emergency rations. As long as things go nominally the imported are optimally varied with local produce and supply all long term nutrient needs as supplements to what is grown locally, but in the event of a serious disaster it provides a significant back up. In the medium term local production will gradually over a 10 to 20 year period would be planned to evolve to supply in the high 90's percentage of mass of consumables with imports gradually dwindling from initially 100% of caloric mass to low single digit percentages. At that point in time Mars could be economically self-sufficient for food because it could be exporting the excesses it generated of food stuffs meeting the vast majority of dietary needs by mass and effectively trading that for some items that might be taking another 50 to 100 years to have locally sourced on Mars (for example tree products etc.).

The key is to not be wasting Earth manufactured emergency supplies, but in fact planning them out and integrating them into a balanced diet as the variety of local products built up.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/12/2016 07:08 PM
The reason I asked about what food weight would probably be per person is that we can also have an idea for the trade-off between sending food and growing it there. I don't know about pressure vessel weight, but with one ton we can have on earth a greenhouse to feed a 4 person colony plus the fertilizer it will need for the food. At the end of the growing period we will have the food and sufficient residue for growing food through decomposition, such as mushrooms. I am all in favor of redundancy, food from earth + algae from clear tubes + greenhouse(s) with algae plus higher crops + decomposition + insects or fish or chickens AFTER we have a sufficient feed stream for them. I am not a friend of Soylent philosophically since it is not that much different from the feed mixes we create for the animals but yes, it is a solution. I like where this discussion is going.
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 01/13/2016 12:05 AM

Chickens are relatively efficient, so far as vertebrates go, at turning insect protein into some other package of protein, but nowhere near as efficient as eating the insects directly! As for palatability; that's mainly a psychological problem in Western societies - 80% of countries eat some insects in their diet (and 1,000 species of insects are eaten regularly). Even for Westerners, once you get over the hurdle of that first bite most people find them tasty enough (it helps if they don't have wings, legs and eyes at the point of consumption!).

My favourite suggestion at the moment is mealworms. They're easy to grow - lots of hobbyists do so at home to feed their reptile pets - and can be fed algae. I've tried them myself and they're rather nice in a chili! (Or stews, flans etc.) And you can turn them into flour to make biscuits and bread out of. And, after all, what's the real difference between a mealworm and a prawn?

And anyone who can't bring themselves to eat them? Well, they don't get to go!

Actually common poultry birds do pretty well as far as conversion goes.
https://en.wikipedia.org/wiki/Feed_conversion_ratio
The best seems to be tilapia.
The one that's really inefficient are cows.

Cattle will not happen until mega structures are built.

So no need to force anyone to eat something they don't want to unless you want to skimp on your food system or are trying to fit in inside one or two small modules.

Of course I'm thinking about communities of a few hundred or more vs a small group as the subject is about scaling.

Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/13/2016 01:04 AM
Yes, the issue is "scaling agriculture".  I too see a progression. 

1) Get algae growing
2) Get processing equipment going for algae to make pellets for food/and or for feeding fish/animals.
3) Get hydroponic gardens going.
4) Get tilapia growing to eat the algae.  Fish waste goes to the hydroponic gardens for fertilizer.
5) Get chickens going, eating algae pellets with some variety foods from the hydroponic gardens.
6) Get algae eating mealworms going for food and to supplement the chickens.
7) Catfish can be introduced at this time.
8) Introduce rabbits.
9) With larger structures, grains can be introduced as well as small cattle breeds, and goats or sheep.

Food might have to be one of the top priorities after power and rocket fuel production for sustainability.  Then they could proceed to mining/manufacturing.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/13/2016 01:51 AM

Actually common poultry birds do pretty well as far as conversion goes.
https://en.wikipedia.org/wiki/Feed_conversion_ratio


As I said two pages ago, this assumes modern poultry techniques: Improved hybrids coming from a broad genetic base coming out of a series of crossings that contain quite a bit of intellectual property. You need whole breeding flocks and optimized feed to get those ratios, subtherapeutic use of antibiotics, good veterinary control. More realistic feed ratio for chickens on Mars is 3 or 4 to 1 and you will have trouble even keeping that in the long term due to incest unless you constantly import unrelated chickens (or more likely eggs) from earth. I am not sure about fish and insects but you will have similar issues too.

Yes, the issue is "scaling agriculture".  I too see a progression. 

1) Get algae growing
2) Get processing equipment going for algae to make pellets for food/and or for feeding fish/animals.
3) Get hydroponic gardens going.
4) Get tilapia growing to eat the algae.  Fish waste goes to the hydroponic gardens for fertilizer.
5) Get chickens going, eating algae pellets with some variety foods from the hydroponic gardens.
6) Get algae eating mealworms going for food and to supplement the chickens.
7) Catfish can be introduced at this time.
8) Introduce rabbits.
9) With larger structures, grains can be introduced as well as small cattle breeds, and goats or sheep.

Food might have to be one of the top priorities after power and rocket fuel production for sustainability.  Then they could proceed to mining/manufacturing.

Honestly, too many animals. The Martian diet will not look like an American meat rich diet but more like a Mediterranean or African or Chinese diet based on plants with supplementary animal protein. Rule of thumb: for each conversion step (animal eating plant or animal) expect a loss of energy by a factor of 3. So 9000 plant calories will turn into 3000 herbivore animal calories and 1000 carnivore animal protein (e.g. salmon). The more animals you add the more energy the base plants (and algae are plants in this context) need to photosynthesize. Now animals that eat the inedible (to us humans) residue are beneficial, but even if you optimize production for it, you can't avoid the increased demand on Net Primary Production.
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 01/13/2016 03:13 AM
Yes, the issue is "scaling agriculture".  I too see a progression. 

1) Get algae growing
2) Get processing equipment going for algae to make pellets for food/and or for feeding fish/animals.
3) Get hydroponic gardens going.
4) Get tilapia growing to eat the algae.  Fish waste goes to the hydroponic gardens for fertilizer.
5) Get chickens going, eating algae pellets with some variety foods from the hydroponic gardens.
6) Get algae eating mealworms going for food and to supplement the chickens.
7) Catfish can be introduced at this time.
8) Introduce rabbits.
9) With larger structures, grains can be introduced as well as small cattle breeds, and goats or sheep.

Food might have to be one of the top priorities after power and rocket fuel production for sustainability.  Then they could proceed to mining/manufacturing.

Also employ maggots for trash recycling then use them as chicken and fish feed.
http://www.bbc.com/future/story/20140603-are-maggots-the-future-of-food
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/13/2016 07:05 AM
As I said two pages ago, this assumes modern poultry techniques: Improved hybrids coming from a broad genetic base coming out of a series of crossings that contain quite a bit of intellectual property. You need whole breeding flocks and optimized feed to get those ratios, subtherapeutic use of antibiotics, good veterinary control.

I appreciate your input very much. But I believe that genetic input from earth would require only a quite small amount of transport capacity. I do hope that antibiotics can be avoided. Good veterinarian control, certainly. Mars will need first class educated people. Plus again support from earth.

Honestly, too many animals. The Martian diet will not look like an American meat rich diet but more like a Mediterranean or African or Chinese diet based on plants with supplementary animal protein. Rule of thumb: for each conversion step (animal eating plant or animal) expect a loss of energy by a factor of 3. So 9000 plant calories will turn into 3000 herbivore animal calories and 1000 carnivore animal protein (e.g. salmon). The more animals you add the more energy the base plants (and algae are plants in this context) need to photosynthesize. Now animals that eat the inedible (to us humans) residue are beneficial, but even if you optimize production for it, you can't avoid the increased demand on Net Primary Production.

I agree that the meat part of the diet will be smaller, something I welcome. But I argue that we are not talking about a scientific base where researchers will spend a limited time of their life for working on Mars. We are (at least I am) talking about colonizing Mars. Conditions will be needed where people want to have a family and raise children which calls for a varied and palatable food supply.

True about the conversion rate in general. But it is not necessary for shrimps, trout or salmon. They would be fed directly from algae and vat produced protein, skipping one conversion. Again the optimum ratio of nutrients for best breeding results can be maintained with these sources. Also with the high growth rate and highly efficient production of algae even with a conversion factor 3 or 4 it will be still more efficient over all than calories from higher plants.

Long term I expect that cloning will help to maintain the genetic quality.

Your valued input however provides insight on what it will need to be 100% autonomous. There will have to be a pool of genetic diversity. Only a sufficiently large community will be able to maintain one. Especially as such source needs to be duplicated for failsafe.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/13/2016 04:03 PM
What follows is a thought experiment:

Each Martian colonist will eat 2 kgs of food per day. Let's assume that 1.5 kgs are from plant sources, and 1kg is from a higher plant. Assuming for simplicity's sake we use all aboveground biomass and throw away the belowground biomass, and using a harvest index of 0.5 we also have 1 kg of biomass that is inedible to people but potentially available for feed. Now if we use all this biomass as feed (and not say for composting human waste or other such necessary uses) with a feed conversion ratio of 3 to 1 we could have 0.333 kgs of animal. Now, it is highly unlikely that this biomass is a balanced animal meal but let's ignore it for the moment. Now Dr Google is not that great in finding the conversion ratio of animal weight to food but here is a tolerable link:

http://www.thebisonranch.com/How%20Much%20Meat%20Can%20I%20Expect.pdf

With a dressing percentage of 70% (from Dr Google for chicken) and a carcass cutting yield of of 70% (this includes all the fat) we have 160 grams of edible chicken, which will not be available at the same time as the plant food. To repeat myself this assumes that the plant biomass is completely edible and nutritious for the animal and that we do not use for other purposes, such as composting the part of the chicken we do not eat like feathers. Also we assume that we do not have any live animal losses. In reality these will not happen, we need to feed human quality feed to the animals, chickens cannot just grow on hay. So I would say that in practice we will be lucky to get 100 gr of Mars grown higher animal protein from the byproducts of 1 kg of higher plant food. Now we need to fill the other 900 grams of food. Let's say we do that with algae. I do not know what we will need for that or what we also get out of the growing process.

My takeaway from this thought experiment is that we should not try to have more than 10-15% of food weight in the diet as animal derived food. We can use this kind of back of the hand calculations to allocate space for growing food of different types in the colony and I am sure that we can get better ratios with other animal or plant production systems but before proposing how to scale agriculture, let's try to get some idea of the mass and energy balances
Title: Re: Scaling Agriculture on Mars
Post by: gin455res on 01/13/2016 09:34 PM
I just found this abstract* which suggests it is possible to fractionate poop, and one of the fractions is mainly bacteria.
 
If this were sterilized, might it be okay to eat this (or maybe feed it to chickens/ insects/ fish)?

I currently eat over a 1-4 hour window every evening (usually 1 hour), essentially one meal a day. 

If once my food has reached my large intestine (after say 8 hours, or definitely by the next morning) [, if I was a hard-core 'colonist' :) ] , and if I drank dilute urine that went down to my colon without interfering with (, or being blocked by, ) any digesting food, would the nitrogen in the urine promote/fertilize?, or hinder? more bacterial growth (and perhaps increase?, or decrease? this potentially bonus source of fecal protein)

(tangent: How many calories of heat is generated by the colonic flora, compared to  human mitochondria, btw?)

I know this sounds icky but trust me this is not attempt to troll or seek attention. This question is curiosity driven.


*http://www.ncbi.nlm.nih.gov/pubmed/7359576
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 01/14/2016 12:50 AM

Chickens are relatively efficient, so far as vertebrates go, at turning insect protein into some other package of protein, but nowhere near as efficient as eating the insects directly! As for palatability; that's mainly a psychological problem in Western societies - 80% of countries eat some insects in their diet (and 1,000 species of insects are eaten regularly). Even for Westerners, once you get over the hurdle of that first bite most people find them tasty enough (it helps if they don't have wings, legs and eyes at the point of consumption!).

My favourite suggestion at the moment is mealworms. They're easy to grow - lots of hobbyists do so at home to feed their reptile pets - and can be fed algae. I've tried them myself and they're rather nice in a chili! (Or stews, flans etc.) And you can turn them into flour to make biscuits and bread out of. And, after all, what's the real difference between a mealworm and a prawn?

And anyone who can't bring themselves to eat them? Well, they don't get to go!

Actually common poultry birds do pretty well as far as conversion goes.
https://en.wikipedia.org/wiki/Feed_conversion_ratio

You were talking about chickens turning insect protein into more palatable forms; I pointed out that it was more efficient, and perfectly palatable, to eat the insects directly.

Quote
So no need to force anyone to eat something they don't want to unless you want to skimp on your food system or are trying to fit in inside one or two small modules.

Any early colony is going to be tightly restricted on resource availability to enable food production; so it's best to be as efficient as possible. So, rather than force people to eat something they don't want to it'll be best not to take any such people in the first place.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 01/14/2016 01:18 AM
When trying to raise money for an impossible venture, you take whatever money you can get. In this case, you take whoever wants to go. "Murdered his own family" might be enough to get your application rejected. "Won't eat worms" isn't.

Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 01/14/2016 11:18 AM
we need to feed human quality feed to the animals, chickens cannot just grow on hay.

Apparently fly maggots can feed on mixed plant/animal waste, even human waste. They are ridiculously high in protein, with a high conversion rate and obviously no competition for human food. Like earthworms, the castings are good for plants. While humans can directly eat the maggots, using them as chicken and fish feed adds diet variation for the humans and enrichment for the animals. That lets you raise animals with minimal competition for human feed.

As a bonus, apparently there's very little disease xfer to the larva if you use human waste as feed. That may be incredibly important in such a closed loop. Adding the maggots as a bridge between cycles reduces the risk of disease amplification.

(Mealworms seem limited to vegetable matter, which is useful, but limited. There's probably a variety of insects that would be suitable (along with earthworms), overlapping (for redundancy) and complementing each other.)
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/14/2016 12:46 PM
First of all, an interesting article on space agriculture (more related to ISS) popped up today:

http://www.dw.com/en/norways-zero-gravity-seedlings/a-18886860

Second: The rule of thumb is that we do not feed human waste to humans without transformation. The output of the toilet needs to go through various chemical and biological transformations in the treatment plant before it can be used as plant fertilizer. If there is even the hint that the human gut bacteria have survived we throw away the material. If you had taken agricultural zoology class you would have heard about all sorts of parasites (tapeworms etc.) which we must make sure they do not find a higher host, let alone a human host again.

Now I am not aware of any experiment to use flies as human food, or animal food for that matter. It is certainly not part of modern agriculture because among other reasons they simply are not available at a reasonable cost as a food source. Not to mention that using them as a feed source invites a new mad cow disease scenario. In caged poultry farms we use conveyors and the like to remove their waste out of the growth chambers so that the flies and other parasites do not grow. I just don't see going the other way on Mars for any reason.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 01/15/2016 02:44 AM
Good thing the Haber process is really straightforward so we just have to combine hydrogen and nitrogen (2 things we already will need to produce in bulk anyway) in a single step process for ammonia fertilizer instead of relying on human poop. Talking like 1 kWh per person per day to not have to worry about sterilizing human poop. Sounds like a net-win for me.
Title: Re: Scaling Agriculture on Mars
Post by: KelvinZero on 01/15/2016 02:53 AM
I guess most people have seen this, it may well already be posted on this thread already, perhaps someone on the thread works there! and it probably has slightly different goals.. I see a lot of leafy vegetables that are the easiest goal but supply few calories for example:

https://www.youtube.com/watch?v=8V54UaUXqXg

..but I do like the fact it is talking about prototypes.

(1) Is this the closest project currently underway to prototyping deployable solutions?
(2) What are the holes in our current technological readiness? ..in the sense of what haven't we done and have to do before we can deploy a "bioregenerative life support system" that could keep a colony alive indefinitely? (spare parts assumed obviously, just no absolutely vital calories or suppliments from earth)
Title: Re: Scaling Agriculture on Mars
Post by: A_M_Swallow on 01/15/2016 04:52 AM
I guess most people have seen this, it may well already be posted on this thread already, perhaps someone on the thread works there! and it probably has slightly different goals.. I see a lot of leafy vegetables that are the easiest goal but supply few calories for example:

(...)

..but I do like the fact it is talking about prototypes.

(1) Is this the closest project currently underway to prototyping deployable solutions?
(2) What are the holes in our current technological readiness? ..in the sense of what haven't we done and have to do before we can deploy a "bioregenerative life support system" that could keep a colony alive indefinitely? (spare parts assumed obviously, just no absolutely vital calories or suppliments from earth)

The base will need sufficient oxygen, water and food to survive until the plants have matured.

I suspect that the plants will need replacing every few years, although they may provide their own seeds and cuttings.

" ... Only half the oxygen." so two greenhouses per person.

More calories - soya beans or peanuts could be added to the mix of plants. Something like rhubarb to provide the minerals.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 01/15/2016 05:34 AM
Now I am not aware of any experiment to use flies as human food, or animal food for that matter.

Maggots, not the flies themselves.

http://www.bbc.com/future/story/20140603-are-maggots-the-future-of-food (http://www.bbc.com/future/story/20140603-are-maggots-the-future-of-food)

http://www.worldcrunch.com/food-travel/china-0-s-maggot-factories-hoping-to-feed-the-world/c6s9713/ (http://www.worldcrunch.com/food-travel/china-0-s-maggot-factories-hoping-to-feed-the-world/c6s9713/)

http://www.abc.net.au/catalyst/stories/3775080.htm (http://www.abc.net.au/catalyst/stories/3775080.htm)

Currently they are used commercially only as dried high-protein powder for intensive animal farming. But for smaller scales like a Mars base or early colony, they'd be fed whole (even live) to the chickens/fish. From what I've read, at least for chickens, it reduces stress on the animals as it invokes a very natural behaviour (which they presumably have a dopamine-reward already "programmed" in.)

If there is even the hint that the human gut bacteria have survived we throw away the material. If you had taken agricultural zoology class you would have heard about all sorts of parasites (tapeworms etc.) which we must make sure they do not find a higher host, let alone a human host again.

In a closed ecology like a Mars colony, there's no choice. You simply won't have enough resources to throw away human waste. That's why including a step like maggots is useful, it adds an extra layer between each cycle of human consumption.

Ie,
human waste -> insects -> chickens/fish -> humans.
animal waste -> insects -> insect castings -> plants -> humans/fish
human/animal waste -> algae -> insects -> chickens/fish -> humans
plant waste -> fungi/insects/earthworms -> humans/fish/chickens...
castings -> plants -> etc

(Throw in a pressure-boiling and/or dessication step, just for belt'n'braces)
Title: Re: Scaling Agriculture on Mars
Post by: fvandrog on 01/15/2016 01:24 PM
Would the amount of fibers in leaves and stems depend on gravity?

In other words, do plants grow fibers purely based on genetics or is it (in my opinion more likely) partially based on structural feedback?
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 01/15/2016 01:42 PM
I guess most people have seen this, it may well already be posted on this thread already, perhaps someone on the thread works there! and it probably has slightly different goals.. I see a lot of leafy vegetables that are the easiest goal but supply few calories for example:

(...)

..but I do like the fact it is talking about prototypes.

(1) Is this the closest project currently underway to prototyping deployable solutions?
(2) What are the holes in our current technological readiness? ..in the sense of what haven't we done and have to do before we can deploy a "bioregenerative life support system" that could keep a colony alive indefinitely? (spare parts assumed obviously, just no absolutely vital calories or suppliments from earth)

The base will need sufficient oxygen, water and food to survive until the plants have matured.

I suspect that the plants will need replacing every few years, although they may provide their own seeds and cuttings.

" ... Only half the oxygen." so two greenhouses per person.

More calories - soya beans or peanuts could be added to the mix of plants. Something like rhubarb to provide the minerals.

The current Sabatier system on ISS is 50% efficient at producing oxygen from CO2. The greenhouse handles the rest. Electrolysis can produce oxygen from water. The engineers will have that handled.

That gets us back to what kind of crops to grow in the greenhouse.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/15/2016 01:54 PM
Again, my grandfather raised chickens.  Algae pellets, along with plant waste can be eaten by chickens.  Chickens will eat human food waste, as well as the parts of plants not eaten by humans.  Same with swine or catfish.  If under intense gardening techniques my backyard can supply chickens, fish, eggs, vegetables, and even corn and wheat is small quantities, then surely Mars with a 24 hour day for daylight piped in and LED lighting in small greenhouses can produce enough food without totally relying on algae.  Chicken, fish, and even small animal waste, along with human waste, and uneaten portions of plants can be composted for plant food and algae food. 

You try eating only high efficiency plant based food for a long time, it will get old real fast.  MRE's get old real fast.  Dehydrated foods get old real fast.  Highly educated people from the westernized world want and need a varied diet period.  It will have to eventually be provided.  One cannot live on algae, beans and rice forever.  Also sterilized food going to Mars in the form of seeds, eggs, or frozen embryos will not need antibiotics for a while.  Earth will have to supply a lot of food, especially grain foods until larger greenhouses can be built.  If and when antibiotics are needed on Mars, they will probably be needed for humans first and animals use the same antibiotics, just different amounts.  So antibiotics will have to eventually be brought or made on Mars. 

I think we have all agreed, algae will be produced first, followed by algae eating fish like tilapia.  Then all sorts of small vegetables, then chickens, rabbits or other small animals.  As agriculture is scaled up, grains will be grown, then silage from grains can be fed to small cattle breeds, sheep, goats, and eventually larger animals which can be grown.  Larger animals will probably not be brought until 50-100 years after Mars colonizes.  Frozen and canned meats may be brought from earth until larger areas are built to raise them. 

Even when the New World was colonized by Europeans, they brought varieties of beans and seeds as well as chickens, pigs, cattle and sheep.  They weren't brought initially, but later.  Of course the New World in return gave us potatoes, tomatoes, corn, okra, and many other plant based foods, which greatly improved the worlds food supply, quality, and diversity.  This in turn helped the entire world to longer lives and better health. 

So a wide variety of foods can help with better health and comfort.  Also, with a large diverse food supply, if one thing is damaged, or a disease pops up in one, there are others to take up slack until corrections are made.  Once excess food is produced on Mars, it can be canned, frozen, or dehydrated for future use or problems.  It would have to be stored, so storage units will also have to be built to contain this food.   
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/15/2016 02:14 PM
I was not aware of the UA project. When I saw the video I went to the website. There is a paper in Acta Hort that I tried to read today, alas it is behind a paywall and I am no longer with any university. I could not understand from the video and the website the growth medium, very important detail. The cover material looks to be clear plastic, but again the material is not mentioned. I cannot judge the technological readiness of the whole vessel, how it would survive deployment or obviously how long it would survive on the Moon or Mars. UA is not an institution known for its competency in hydroponics though I do remember articles on horticulture, the best institutions in this country though tend to be in California (UC Davis and UC Riverside). Another point of note is that funding comes from the Arizona Space Consortium which implies that it is a very low national priority (if it came from NIFA it would be better)

That being said though I really like the piping sunlight with fiber optics part, even if we go underground we can pipe the light in and use supplementary illumination when necessary. I liked that it can shrink for transportation and then expand for production without the need for an EVA and tools to engage in conventional construction. The attempt to make the structure self contained was great, though it can limit in the long term the ability to expand and/or change production method.

I am not surprised that they have trouble getting both the oxygen and half the food necessary, growing food requires far more CO2 than that we breathe out, as I said a Martian greenhouse is going to be a carbon sink that will require constant CO2 pumping if we want to produce sufficient food. In general agriculture is a fiendishly complex system and creating a completely self sustaining system is somewhere in the drawing board rather than the demonstration phase.

Now speaking on self sustaining systems, human waste is too valuable a resource to throw away. We need the Carbon, Nitrogen, Phosphorus and Potassium. We want them though in a format that they are not dangerous. There are several operational methods already that will turn a material full of dangerous pathogens into a nutrient source for plants. Their primary intention is exactly to reduce parasites. I am not sure about how flies and maggots would fit and if they are able indeed to produce a safe edible material.

A backyard intensive farm on earth has advantages that a Martian production facility does not have: an entire ecosystem in the soil. Providing the basic functions of an ecosystem requires quite a bit expenditure and we are not there yet.
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 01/15/2016 02:26 PM
Solid human waste can be exposed to vacuum, dried or even incinerated in a solar oven. Options that would be energy intensive on Earth would be relatively simple on Mars by taking advantage of the hostile environment. No chemicals required. Then it would be safe to use as fertilizer.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/15/2016 03:58 PM
Solid human waste can be exposed to vacuum, dried or even incinerated in a solar oven. Options that would be energy intensive on Earth would be relatively simple on Mars by taking advantage of the hostile environment. No chemicals required. Then it would be safe to use as fertilizer.

Safe? Perhaps. Plant available? Debatable. There is a whole class of emerging contaminants in the environment (e.g.flame retardants on our blankets and mattresses) which enter the biosphere because they are not decomposed in the treatments, since they do not stay enough. There are several streams where 1 in 10 frogs are androgynous from these contaminants. We wouldn't want that kind of thing on our colonists, would we? Composting is IMO a much better solution, at the end we have a nutrient rich organic material to mix with Martian soil Watney style but far more hygienic.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/16/2016 08:04 PM
A truly awesome article popped up today at spacetoday.net from the official website of the US Army, on a research project to make real food for Mars:

http://www.army.mil/article/160761/Army_helps_to_meet_nutritional_needs_of_Mars_astronauts/

Quote
The mission to Mars provides many challenges in vitamin stabilization.

"You can make food that is stable, but vitamins are biological materials that degrade over time," Barrett said. "Especially if there is cosmic radiation; then they are even more susceptible to degradation. Cosmic radiation can damage vitamins and create more of a need for antioxidant vitamins for the astronauts. This could result in malnutrition."

The vitamins need to remain effective and intact during the astronauts' time on Mars, and they also need to remain stable during travel to and from Mars.

"NASA is also interested in stockpiling food there for subsequent missions, which is why they want a five-year shelf life," Barrett said.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/17/2016 12:05 PM
What follows is a thought experiment:

Each Martian colonist will eat 2 kgs of food per day. Let's assume that 1.5 kgs are from plant sources, and 1kg is from a higher plant. Assuming for simplicity's sake we use all aboveground biomass and throw away the belowground biomass, and using a harvest index of 0.5 we also have 1 kg of biomass that is inedible to people but potentially available for feed. Now if we use all this biomass as feed (and not say for composting human waste or other such necessary uses) with a feed conversion ratio of 3 to 1 we could have 0.333 kgs of animal. Now, it is highly unlikely that this biomass is a balanced animal meal but let's ignore it for the moment. Now Dr Google is not that great in finding the conversion ratio of animal weight to food but here is a tolerable link:

Algae?

How about each colonist eats:
- 0.5kg of fish or chicken. These are produced from 1kg of algae.
- 1kg of algae, synthesised into flour (bread) and other staple foods / or some other forms of carbohrdrate synthesis.
- 0.5kg of tomatoes and lettuces grown under artificial light
- A synthetic flavours unit producing trace amounts of flavours to make the above taste good.

Total: 2kg of algae and 0.5kg of salad.

The challenge really is to make something with the nutritional and taste properties of rice, pasta or potato from algae.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/18/2016 12:17 AM
Algae?

How about each colonist eats:
- 0.5kg of fish or chicken. These are produced from 1kg of algae.
- 1kg of algae, synthesised into flour (bread) and other staple foods / or some other forms of carbohrdrate synthesis.
- 0.5kg of tomatoes and lettuces grown under artificial light
- A synthetic flavours unit producing trace amounts of flavours to make the above taste good.

Total: 2kg of algae and 0.5kg of salad.

The challenge really is to make something with the nutritional and taste properties of rice, pasta or potato from algae.

1 kg of algae will at best lead to 0.25 kg of fish or chickens. Considering that we do not eat feathers or guts or scales 0.15 to 0.2 is more realistic, 0.10 more conservative considering also that algae on its own is NOT a nutritionally balanced meal either for chickens or fish. That is on top of the issues with veterinary control, genetic diversity etc that come with having animals or the time it takes to grow the animal and when it becomes available to eat. Supermarkets create the illusion that meat is available all of the year, in truth not so much.

How do you do carbohydrate synthesis? What is the machinery required? What are its spare parts? What are the feedstocks? Byproducts and their potential utility? What is the size of the logistic tail coming from earth? Honestly I am not familiar

Tomatoes and lettuce sure, but they are not high calorie food. At the very least you will need oil for your salad, which you will need to grow locally. Tubers and grains will also help.

Where are synthetic flavors coming from? If earth, how many will survive the trip and not get decomposed by cosmic radiation? If local, what is their feedstock? Artificial vanilla (which is 90% of all vanilla consumed) today mostly comes from a petroleum feedstock. Several natural flavors come from the shells of insects, do we want to grow insects just for their coloring?

Do not misunderstand me, I am not here to shoot you down. I am just trying to show the unknowns so that they can be filled
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 01/18/2016 12:33 AM
I'm a meat-eater, but I'm 99% certain that you're way better off with a vegan diet if you are in an energy-constrained state like a Mars colony.

It's fun to think of chicken and fish, but feeding single-celled protein some methane and ammonia is a VERY efficient way to produce protein (with some small amount of carbs and fats), and algae is very effective at fats. Probably are ways to efficiently produce carbs, too. But feeding this to chicken and fish is throwing away like at least half of the food energy and is going to double, triple, or even quadruple the energy needed to produce food.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/18/2016 07:46 AM
Algae are a very efficient producer of both oil and carbo hydrates. Grains I just cannot see in the mix, space and time inefficient. I would bet, calories from chicken or fish fed algae and bacteria protein takes less ressources to produce than grains even considering the conversion losses.

But I agree that 500g meat or anywhere near that is not economical. I can and do produce delicious meals with 50g of meat per dish.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/18/2016 08:18 AM
Given that Tilipia are "designed" to eat algae, and 1.5:1 is feasible, we could probably assume 2:1.

Main thing is algae will be cheap. They circulate through tubes next to the photovoltaic panels. So if we need 2kg of algae for 1kg of fish, or 3kg for 1kg of chicken, that still makes chicken cheaper than potatoes. OK, protein powder - made from methane, will be cheaper still.

Good to know Vanilla is made from petroleum stock. That will be easy, as will salt. Pepper is rather harder - though can be imported as the volume is low.

So meat is easy. But still the essential question is how do we turn Algae into the bulk carbohydrate equivalent to pasta or rice or potato, which make up the bulk most people's diet?
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/18/2016 09:31 AM
So meat is easy. But still the essential question is how do we turn Algae into the bulk carbohydrate equivalent to pasta or rice or potato, which make up the bulk most people's diet?

That's something worth putting research money into. It can be done and will be done, providing the biggest share of all calories produced together with the high quality oil also grown by algae.

We see vegetarian and vegan meat imitation products getting better. But not yet much work on grains replacement. I think there is some work on using algae as an additive to other products, but have no source. Still a long way to go.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/18/2016 10:03 AM
Grains on Earth are very cheap, and already healthy. So there's no incentive for anyone to research an algae-based grain substitute. Once off Earth though, it will be essential.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/18/2016 03:07 PM
Grains on Earth are very cheap, and already healthy. So there's no incentive for anyone to research an algae-based grain substitute. Once off Earth though, it will be essential.

I believe some thought is given to algae as a future staple food for the growing population. However purely scientific basic research, nothing on real application besides adding some algae to products for increasing nutritional value.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/18/2016 06:08 PM
Grains on Earth are very cheap, and already healthy. So there's no incentive for anyone to research an algae-based grain substitute. Once off Earth though, it will be essential.

I believe some thought is given to algae as a future staple food for the growing population. However purely scientific basic research, nothing on real application besides adding some algae to products for increasing nutritional value.
You (I think) mentioned algae being used to make flour. Is that the right kind of flour to make bread?

I found this: Milk from algae. http://www.workoutplan.com/milk-made-from-algae-the-new-dairy-alternative/

Eggs from chicken (from algae), and flour from algae. That's the pancakes sorted out :)
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/18/2016 06:24 PM
You (I think) mentioned algae being used to make flour. Is that the right kind of flour to make bread?

Yes it was me. It is only a concept idea of mine though. Algae produce starch. Starch is the main component of flour. Some proteins with special properties make it flour. That's gluten plus no doubt some others that give it the needed property and flavour. So if you can produce the right kinds of protein and mix them with starch you should get a product that can be used as flour.

Edit: Interesting article on algae milk. Did you notice they mentioned algae flour as well?
Quote
Solazyme released Algal flour in October, and Algae milk is made from this new Algal flour.

Nothing on the properties of this flour though.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 01/18/2016 08:51 PM
Algae are a very efficient producer of both oil and carbo hydrates. Grains I just cannot see in the mix, space and time inefficient. I would bet, calories from chicken or fish fed algae and bacteria protein takes less ressources to produce than grains even considering the conversion losses.

But I agree that 500g meat or anywhere near that is not economical. I can and do produce delicious meals with 50g of meat per dish.
I'm not sure if you're confused by this or not, but it's an important point that we should make clear right here:

Chicken and fish do not produce protein. That fixed nitrogen comes from somewhere, so it's in their diet in the form of protein (because fish and chicken aren't capable of processing ammonia or nitrates).

You don't somehow get more protein by sending that protein through a chicken or a fish. Chicken and fish don't consume oil and carbohydrates and produce protein. That's not how it works. So it's better to instead eat the vegetable or bacterial or fungal protein directly.

You can make bread or meatless patties using these non-meat protein sources. Processing technology is also improving to the point that the texture and taste can resemble meat quite closely (though surely people will find their own way of preparing this food without necessarily just trying to copy meat).
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/18/2016 09:11 PM
@Robotbeat
I am not sure what you are arguing.

I argue that algae and protein from bacteria are more efficient than producing staple foods with higher plants like grains and oil seeds. I argue producing a wide variety of products from algae and bacteria will be the base of food production. I think so far we are in agreement.

I only add the argument that calories from fish or chicken will still be more efficient than growing staple foods from higher plants. I don't deny that it is less efficient than using algae and bacteria protein directly as food for humans. I just argue that we probably can afford a small amount of animal food using algae as they are very efficient and that people will want it.

So the food base will be algae, bacterial protein and vegetables, herbs, spices, that add not so much calories but variety, people will want to have.

Plus of course there will be programmers and we know that programmers need coffee. So we need a source of coffee too. ;D
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/18/2016 09:49 PM
Human waste alone is and can be fertilizer for plants.  It was used in Asia in rice patties for centuries.  The studies of sewage toxins is the problem of cleaning solutions and various chemicals people flush into the sewage system.  Composting toilets can be used on Mars for manufacturing fertilizer, along with animal waste for fertilizer.  Once composted, (methane is a byproduct), it is safe and sterile for fertilizers.  Mixed with Martian soil, who knows.  NASA did discover, through one of the landers, that potatoes could grow very well on Mars. 

Oh, chicken and fish will be far more palatable than anything made from algae or bacteria.  Both can be fried, baked, stewed, or grilled.  That, at least, is 8 different tastes just from two sources.  Throw in rabbit, and it goes to 12.  Throw in turkey, quail, and maybe pot bellied pigs.  Now we are getting some choices. 

In the natural cycle of things, animals produce the manure and urine for fertilizers, which the plants love. Even algae must eat something to produce their oils and proteins.  CO2, water, but does algae need something else?
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 01/19/2016 05:06 AM
In the natural cycle of things, animals produce the manure and urine for fertilizers, which the plants love. Even algae must eat something to produce their oils and proteins.  CO2, water, but does algae need something else?

Even algae will need a source of nitrogen, as well as trace elements naturally found in Earth's soil.

Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/19/2016 12:16 PM
@Robotbeat
I am not sure what you are arguing.

I argue that algae and protein from bacteria are more efficient than producing staple foods with higher plants like grains and oil seeds. I argue producing a wide variety of products from algae and bacteria will be the base of food production. I think so far we are in agreement.

I only add the argument that calories from fish or chicken will still be more efficient than growing staple foods from higher plants. I don't deny that it is less efficient than using algae and bacteria protein directly as food for humans. I just argue that we probably can afford a small amount of animal food using algae as they are very efficient and that people will want it.

So the food base will be algae, bacterial protein and vegetables, herbs, spices, that add not so much calories but variety, people will want to have.

Plus of course there will be programmers and we know that programmers need coffee. So we need a source of coffee too. ;D
If algae cost one Mars Dollar per kg, with efficiency losses and the water tanks / chicken coops, Tilipia will cost $3/kg and chicken $4/kg (bones and head included).

We can get out protein from Algae steaks if we want, or pay a bit more for fish or chicken.

Meanwhile, potatoes/rice/wheat cost $10/kg. So can we take our $1/kg algae, and convert them into something similar? Perhaps costing below $2/kg.

And tomatoes cost $5/kg. Which is a lot for 90% water, but we don't need too much of it. (We can probably extract vitamin C from the algae).

Peppar and curry sauce, and anything brought from Earth might cost $500/kg. And sewage will cost $0.2/kg, as useful feedstock.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/19/2016 03:18 PM
I've eaten and tasted textured soy protein.  It is ok, but it just isn't the real thing.  Algae might be the beginning, but other foods will have to eventually be brought, and a variety of vegetables, even with Martian soil, human and fish waste fertilizers, can be raised in a very small amount of space.  I've also eaten freeze dried foods.  Again, it is ok, but can't beat fresh. 

Those of you who do not grow a vegetable or herb garden don't realize how little space you need.  This is especially true if crops are grown inside, in a controlled environment, year round.  I had a 12' x 12' patch.  In it, I grew enough green beans to last my wife and I a year plus give some away.  In the same patch I grew enough tomatoes to last almost 2 years with canning.  Also in that patch, I grew some seasonal collards and some seasonal cucumbers, all in less than 5 months.  I could have intensely worked this year round if I didn't have other projects to do and had over winter, carrots, beets, rutabegas, onions, turnips, collards, and radishes.   At the very least a 12' x 12' patch in a small Martian greenhouse can provide a whole whale of a lot of vegetables and variety for a family. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/19/2016 06:33 PM
Whoever thinks that having animals is easy, has never had to design an animal production facility or a facility treating their excrement. I've been searching the internet to see indeed how good is tillapia fed on a diet of algae in a tank system and the answer is not so good. From http://www.waiwiki.org/index.php?title=Algae_for_Tilapia

Quote
Under most unnatural feeding conditions tilapia are unable to sufficiently ingest high volumes of algae. They may need constant grazing to fulfill their nutrient requirements.[444] Tilapia (Sarotherodon niloticus) grow better on fishmeal (fish meal may contain 74% protein and 8% lipids.[445]) than on a 25% protein green algae meal (Cladophora glomerata). Weight gain decreased as the level of algal protein increased as replacement of fish meal. Protein digestibility was highest on a 5:1 ratio (fishmeal : green algae meal).[446] Protein synthesis (with normal sulfur and carbon content) by green algae during the night may match protein synthesis during the day (in Dunaliella tertiolecta).[447] Protein derived from algae does not promote adequate growth in Rainbow trout.[448] Fish fed 5% ulva meal (Green algae; Ulva rigida) showed increased growth, feed conversion ratio and protein efficiency ratio.[449] Ulva meal may replace soy bean meal to the extent of 20% without negatively affecting growth of male larval tilapia. Feed conversion ratio increased with increasing ulva meal content.[450] Green algae meal (Hydrodictyon reticulatum) may replace meal to the extent of 25% without negatively affecting growth of Oreochromis niloticus and Tilapia zillii fingerlings.[451] Spirulina maxima meal protein can replace up to 40% of the fish meal protein in Oreochromis mossambicus fry diets without negatively affecting growth.[452]


From http://www2.ca.uky.edu/wkrec/TilapiaTankCulture.pdf

Quote
Tank-cultured tilapia can have very efficient feed conversion ratios (FCR). The time period for FCR can be
days, weeks, the length of the tank  production cycle, or a year. FCRs  in the range of 1.4:1 to 1.8:1 are
common with tilapia and are some  of the best in animal agriculture.  While FCR is one of the most important benchmarks for measuring the efficiency of an operation, FCR alone does not give a true measure of production. An artificially low FCR can be created by underfeeding, so it is important to consider the growth rate also.

But as Bawdy et al note at https://ag.arizona.edu/azaqua/ista/ISTA8/FinalPapers/11%20Nutrition/8.%20TARTIEL.doc.

At a 75% algae meal, FCR was at 3.24 for Chlorella and 2.74 at Scenedesmus algae.

The high FCRs in the literature and at the JSC experiments are with soymeal and the like, not algae. You will need a very balanced meal approach to growing tillapia, including vitamin and micronutrient supplements for the fish in fish available form.

I am not in favor of a vegan diet (a vegetarian diet is useless, if you have the animal you might as well eat it). However Mars grown animals except perhaps insects shouldn't show up before significant infrastructure is created. Meat ought to come from Earth.

Grains are an integral part of all high quality animal feeds. Chickens cannot grow without grains, cows have bad FCR when relying on a low grain diet. Grains also survive a long time without need for refrigeration or other special storage conditions. I am pretty sure that they will show up quite early in a Mars agricultural system. And yes, algae require nitrogen fertilization.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 01/21/2016 02:16 PM

Quote
Tank-cultured tilapia can have very efficient feed conversion ratios (FCR). The time period for FCR can be
days, weeks, the length of the tank  production cycle, or a year. FCRs  in the range of 1.4:1 to 1.8:1 are
common with tilapia and are some  of the best in animal agriculture.  While FCR is one of the most important benchmarks for measuring the efficiency of an operation, FCR alone does not give a true measure of production. An artificially low FCR can be created by underfeeding, so it is important to consider the growth rate also.

But as Bawdy et al note at https://ag.arizona.edu/azaqua/ista/ISTA8/FinalPapers/11%20Nutrition/8.%20TARTIEL.doc.

At a 75% algae meal, FCR was at 3.24 for Chlorella and 2.74 at Scenedesmus algae.

The high FCRs in the literature and at the JSC experiments are with soymeal and the like, not algae. You will need a very balanced meal approach to growing tillapia, including vitamin and micronutrient supplements for the fish in fish available form.

I am not in favor of a vegan diet (a vegetarian diet is useless, if you have the animal you might as well eat it). However Mars grown animals except perhaps insects shouldn't show up before significant infrastructure is created. Meat ought to come from Earth.

Grains are an integral part of all high quality animal feeds. Chickens cannot grow without grains, cows have bad FCR when relying on a low grain diet. Grains also survive a long time without need for refrigeration or other special storage conditions. I am pretty sure that they will show up quite early in a Mars agricultural system. And yes, algae require nitrogen fertilization.

Those FCR figures are worse than I thought.

However, it's early days for algae and perhaps we need to breed algae better suited to fish and chicken diets.

It seems clear that there won't be a generic algae green gooh that we use, but there might need to be several parallel algae streams.

There is little incentive to focus on different algae breeds, other than for bio fuels. As said above, staple foods are abundant and cheap to produce, given that agricultural land is almost free.

If in the USA, a luxury house costs $2,000/m2. Imagine now that farmland also costs $2,000/m2. We would probably be doing a lot more research into algae and direct synthesis of proteins from methane.

Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/21/2016 02:41 PM
I have been big into gardening and some history of homesteading.  In the 1800's 40 acres and a mule east of the Mississippi, one could have a homestead and supply enough food for their family and have some to sell or trade.  10 acres for pasture, 10 acre woodlot for firewood and construction, 10 acres of either cash crops or animals to sell or trade.  The pasture would contain a milk cow and one or two draft animals.  Excess grass from this pasture was harvested for hay to feed the animals in winter.  That leaves 10 acres for home, barn, blacksmith shop, chicken house, vegetable garden, fruit trees and such. 

Fast forward, today a modern "homesteader" can actually get by on 1-2 acres.  This would include intensive gardening with a greenhouse.  Fish raised in a small pond or tank for tilapia.  Small animals such as chickens, rabbits, and goats.  Grains such as wheat and corn can be raised, and with a good water supply rice. 

Now, on Mars with total food being grown in greenhouses with year round climate control, probably less than one acre can provide all the food with some animals for a family.  Maybe even a quarter or half acres.  We aren't talking about a whole lot of space for complete food production including palatable foods. 

It has been tried a few years ago, don't remember the program, but it did have some drawbacks.  Some emergency food was sent in to the participants.  Also ants got through the system somehow.  It was supposed to mimic a Mars colony.

I think this should be tried again with a solar power supply system for extra power to use heat to speed up the composting, lighting for plants at night and such to increase food production.  This old system was supposed to have enough plants to provide the oxygen for he participants to breathe.  With the extra solar power production, this could be supplemented by cracking the CO2 as would actually be done on Mars.  Extra water could be taken from the air like it might be done on Mars, or brought in via mining ice. 

I also think food production should be double what people might actually need.  Excess should be stored as on earth, by dehydration, canning, and freezing.  This should also be done because even supply ships from earth might not get there but every synod.  Earth could bring specialty foods that could not immediately be produced on Mars.  This is done now with ISS.  Mars would have longer wait times though. 

One side effect to attempting to simulate Martian conditions on earth with food production, is it would help people on earth apply what is learned to increase production on earth. 
Title: Re: Scaling Agriculture on Mars
Post by: fvandrog on 01/28/2016 05:44 AM
It has been tried a few years ago, don't remember the program, but it did have some drawbacks.  Some emergency food was sent in to the participants.  Also ants got through the system somehow.  It was supposed to mimic a Mars colony.

That was Biosphere 2 (see wikipedia article (https://en.wikipedia.org/wiki/Biosphere_2)).

To quote from it:

Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts, though heavily publicized, ran into problems including low amounts of food and oxygen, die-offs of many animal and plant species, squabbling among the resident scientists and management issues.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 01/28/2016 03:34 PM
It has been tried a few years ago, don't remember the program, but it did have some drawbacks.  Some emergency food was sent in to the participants.  Also ants got through the system somehow.  It was supposed to mimic a Mars colony.

That was Biosphere 2 (see wikipedia article (https://en.wikipedia.org/wiki/Biosphere_2)).

To quote from it:

Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts, though heavily publicized, ran into problems including low amounts of food and oxygen, die-offs of many animal and plant species, squabbling among the resident scientists and management issues.

No Biosphere 2 was never supposed to "mimic" a Mars colony, the only actual correlation was the full duration test was supposed to last two years which was noted to correspond with a round trip to Mars. Biosphere2 was simply supposed to be a test of a multi-environment, closed loop system which had numerous problems and issues before, during and after it's runs that meant it never reached its potential*.

And more specifically it's exactly the WRONG way to go about building the type of system spacenut is describing :)

There have been several successful runs of plant/animal/human very-close-to-closed loop systems but funding is hard to come by.

Spacenut; As you noted when you mentioned digging into the history of homesteading and intensive gardening, people have put a lot of effort into getting systems tweaked to provide sufficient output with minimum input of energy and labor. For the most part the methods arrived at have knock-on effects when you try and "close" the system without careful attention to detail. As an example intensive composting system have issues in a closed system due to putting out large amounts of CO2 and heat which are not always linear. Similarly co-production systems (Aquaponics for example) tend to skew the humidity levels nearby, again in a non-linear fashion.

Point is what needs to be done is similar to your suggestion but with careful attention to making the system as "modular" as possible which is often counter-intuitive for someone approaching the idea from a home-steading/intensive gardening perspective mostly because you have less "buffer" between systems in an enclosed space.

Incremental increase in both size and time/length of experiments is the most likely method to follow, but again funding is most often an issue. (Isolation for accuracy isn't exactly cheap and you need it to reduce the variables for accurate data collection. Trust me, I was with a group that discussed NUMERIOUS possible methods of achieving such isolation without resorting to mega-buck, mega-structures as our funding was non-existent :) )

I very much think approaching from the direction of homesteading/intensive gardening is a good idea as trying to construct a "balanced" artificial system is difficult. Your priority is pretty much survival and support of the human element with enough allowed "depth" to cover breakdowns and maintenance outages.

Care to describe what you see as a basic "module" for what you're thinking?

*= Biosphere 2 was frankly over ambitious and despite money spent, badly designed as well. The structure actually reduced the light levels enough to cause many of the issues and the multiple bio-regions in close proximity actually hindered overall viability. Couple that with the known (but ignored) problem of concrete oxygen absorption and the ants (they were found during construction but everyone expected them to die off, except of course the local specialists who knew they were a damn hardy species :) ) ego clashes, and well...

Thing was there where suggestions early on for a more limited and less grand follow on to Biosphere 1/2 but those didn't garner enough interest and/or support while the more complex concept did. Pretty much everyone agrees (now) that the less impressive concepts probably would have yielded better and more data :)

Randy
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 01/28/2016 03:51 PM
Well on Mars if there is plenty of excess power from solar panels.  Some of the issues can be dealt with.  Mars is cold, so excess heat can be used to heat the greenhouses.  Excess CO2 can simply be vented into the atmosphere.  Methane produced from composting can be used for rocket fuel.  After composting, the waste is simply fertilizer for the plants.  Fish can be grown where any excess water vapor is needed for plants requiring more atmospheric water vapor.  Or excess water vapor can be cracked for hydrogen and oxygen.  Power and equipment will be needed for this. 

Unlike the biosphere projects, extra power and equipment to fill in gaps and or speed up natural processes will be needed.  Power will be needed for lighting and growing plants at night, thus increasing productivity unlike homesteaders on earth. 

I do think we need to do something like biosphere with plenty of power and the right equipment and test it in Alaska or somewhere with similar temperatures to Mars .  I would like for NASA to head his up.  Use soil from areas of earth with similar soil conditons.  See what we need to mix into "Martian" soil for plant growth. 

I think getting to and from Mars is relatively easy with today's technology.  Living there and growing food, is the key to long term survival and colonization.  This needs to be tweeked on Earth, or even the moon.  Also like everyone has talked about, algae will be first, followed by plants, fish, and small animals.  I think it will take longer for grains and larger animals to be brought up.  Larger animals might even require artificial gravity in a large spinning spacecraft to survive a trip to Mars. 
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 01/28/2016 05:43 PM
Well on Mars if there is plenty of excess power from solar panels.  Some of the issues can be dealt with.  Mars is cold, so excess heat can be used to heat the greenhouses.  Excess CO2 can simply be vented into the atmosphere.  Methane produced from composting can be used for rocket fuel.  After composting, the waste is simply fertilizer for the plants.  Fish can be grown where any excess water vapor is needed for plants requiring more atmospheric water vapor.  Or excess water vapor can be cracked for hydrogen and oxygen.  Power and equipment will be needed for this.

Kind of why I wanted to get deeper into this, thanks :) Actually you can't "just vent" the excess CO2, or use the "methane as rocket fuel" unless your system is isolated along with it's flow path. Which means getting the excess heat out requires another connecting system which is what most folks are trying to avoid :) (Over complexity and the need for non-natural interconnects between systems)

I've seen it argued, (oh have I seen it argued :) ) that composting might not be the best way in such a closed system. I've seen both anaerobic and aerobic systems suggested to deal with wastes and produce nutrients for the rest of the system. I'm on the fence about how much mechanical/automation interconnects there would be for an overall system. While having co-mingled segments can be beneficial there is a sound argument for not doing so since increased maintenance and operations requirements often negate the benefits in a closed system.

Quote
Unlike the biosphere projects, extra power and equipment to fill in gaps and or speed up natural processes will be needed.  Power will be needed for lighting and growing plants at night, thus increasing productivity unlike homesteaders on earth.

Yes, but... :) Actually the Biosphere projects DID have artificial interconnects in a lot of places and specifically one of Biosphere 2s issues was the maintenance and functionality of those interconnects under extended use. I personally favor smaller, modular systems over a larger one but that normally increases your interconnects somewhat. Design details are important here but it's also where most discussions bog down due to varied personal assumptions :)

Quote
I do think we need to do something like biosphere with plenty of power and the right equipment and test it in Alaska or somewhere with similar temperatures to Mars .  I would like for NASA to head his up.  Use soil from areas of earth with similar soil conditons.  See what we need to mix into "Martian" soil for plant growth.

Antarctica and near the north pole are already considered "analogs" for Mars but really you CAN do this anywhere which is a point often missed. If you assume everything "outside" your module is hostile so you can't let it in and therefore control all inputs precisely your overall data is that much more accurate. However that's also why these types of experiments are so costly :) On the other hand allowing more "natural" inputs (such as sunlight) can bite you in the keester as Biosphere 2 found out and can be more expensive than doing everything artificially is you make the wrong design and/or construction choices.

The more inputs you directly control the more efficient the overall system throughput is, but the more expensive (both cost and energy wise) the effort is. It also makes the system more vulnerable to input system failures of course which is NOT normally a consideration when pushing for efficiency and/or accurate data since any long term failure is reset event for the experiment anyway.
Hence the idea of short runs that gradually build up in length as the bugs are worked out of the system and NOT focusing on gathering hyper-accurate data.

In other words you avoid treating the whole process as an "experiment" but instead work towards incrementally building up an actual working system.

Soil: We're making that from scratch. Regolith both Martian and Lunar so far as we know isn't going to be good for much other than supporting the plants as a medium until and unless we build it into "real" soil. The good news is we are well aware of the most efficient methods of doing that, the "bad" news is I don't see a large need or desire for doing so as it won't be the main focus of the primary system. We'll make and use soil from regolith of course but the main system will most likely be hydro or aeroponics to maximize throughput and allow maximum automation.

Again the main design question or such a project is how do you cheaply isolate the system repeatedly to do your runs? (No joke the group I was with figured that giant heat-sealed plastic bags and an handy box-cutter knife for when things crash for the umpteenth time to slash an opening :) )

Quote
I think getting to and from Mars is relatively easy with today's technology.  Living there and growing food, is the key to long term survival and colonization.  This needs to be tweeked on Earth, or even the moon.  Also like everyone has talked about, algae will be first, followed by plants, fish, and small animals.  I think it will take longer for grains and larger animals to be brought up.  Larger animals might even require artificial gravity in a large spinning spacecraft to survive a trip to Mars. 

Overall I can't say I disagree but getting the basic system designed and running and then doing the tweaking seems to be lacking :) As I said it seems initial costs are a problem as well as getting a decent design together and getting it running. While it would lack the polish and "credibility" of something like Biosphere 2 I'm not seeing where any empty warehouse or vacant lot anywhere in the world couldn't be used to get the basics up and running but everyone seems fixated on finding something as close to a Mars analog on Earth to start with when it's not clear it's needed...

Randy
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 01/28/2016 06:21 PM
It is nice to follow the conversation here, here are a few of my pointers:

There will not be an excess of CO2 at least in the medium term, rather there will most likely be a lack of CO2. We consume a small part of what plants photosynthesize, plants need carbon to build the rest of their tissue.

The approach to Martian agriculture will be closer to high intensity urban agriculture rather than homesteading in the Wild West. I am fully aware how several US reports invoke the mythology of the West to help sell all of space colonization, in practice though we would most likely be talking about a communal rather than an individual effort, more kibbutz and less homestead. Homesteaders had an advantage Martians don't have: a soil ecosystem.

I am not very friendly to soil based agriculture at least at the start, if anything The Martian points to is how we will need to even build the soil. I do see composting as a method to recycle the nutrients (as in N,P,K) and also as a way to also grow food such as pleurotus mushrooms. We will mix the final output of mushroom growth with (preferrably) treated waste from the humans and all of that with native martian soil. This soil will go to greenhouse II or III to create agricultural soil, eventually but not at first, we have far better intensity (as in smaller biological cycle) and higher yield with hydroponics.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 01/28/2016 06:52 PM
Some Antarctic fungi sent to ISS for an 18-month study have shown their ability to survive in Mars-like conditions:

http://www.rdmag.com/news/2016/01/antarctic-fungi-survives-martian-and-space-conditions

http://www.foxnews.com/science/2016/01/28/antarctic-fungi-may-hint-at-potential-for-life-on-mars.html

That sounds like good news - especially if they could be genetically modified to enhance their properties for increased survival, or for our needs, etc.


Quote
After the year-and-a-half-long voyage, and the beginning of the experiment on Earth, the two species of lichens ‘exposed to Mars’ showed double the metabolic activity of those that had been subjected to space conditions.
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 01/30/2016 04:37 AM
There will not be an excess of CO2 at least in the medium term, rather there will most likely be a lack of CO2.

I somehow suspect there won't be a lack of CO2 on Mars! :)
Title: Re: Scaling Agriculture on Mars
Post by: MickQ on 01/31/2016 12:58 AM
Years ago I saw a design for a Mars greenhouse designed specifically to put Oxygen onto the atmosphere.
It was full of trees ( cannot remember the species ).  It had an opening at ground level on one end and another at the top on the other end.  Atmosphere entered at the bottom, was converted by the trees to O2 which naturally rose up and left via the top opening.  No moving parts.

Is this design workable/ useful with regards to producing Oxygen for consumption ?
Title: Re: Scaling Agriculture on Mars
Post by: Geron on 01/31/2016 01:44 AM
Plant protein would be more efficient than raising animals for meat, also less cruel.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 01/31/2016 09:03 AM
Plant protein would be more efficient than raising animals for meat,

More efficient, but not fulfilling all human needs efficiently.

Quote
also less cruel.

Let's not go there. Veganism is an extremist cult and I abhor extremism.

Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 02/01/2016 02:01 PM
Some Antarctic fungi sent to ISS for an 18-month study have shown their ability to survive in Mars-like conditions ...
Some might consider it environmental terrorism, but an interesting experiment would involve depositing an assortment of lichens on Mars to see what they develop into.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/01/2016 02:22 PM
All I was referring to is to have NASA conduct food production experiments on earth like the biosphere projects over 2 years or more.  However, have unlimited power to see how much will actually be needed.  Placed in a cold part of the earth, because Mars is cold.  Excess heat from composting can be captured and used to heat the living units by using heat exchangers and forced air furnace equipment.  O2 will be a by-product of plant growth.  Methane and CO2 from composting.  CO2 can be cracked for the extra oxygen needed for humans, methane is light and will rise and can be captured, filtered and liquefied for whatever needs. 

I assume water on Mars might have to be mined, or made form CO2 and methane.  Water can be easily stored in any type of tankage or bladders.  Water can be stored in elevated tanks with composters underneath to keep it from freezing.  There are any number of solutions.  They all should be tried to see which is most effective or efficient under MARS conditions, unlike the biosphere projects which attempted to have a complete ecosystem contained.  Mars will not for years be a complete ecosystem.  A lot of power will be needed to compensate for a natural long timeframe occurring ecosystem.  Power will be needed for fuel production, oxygen production, water mining and recycling production, lighting for greenhouses to increase speed of plant and algae growth, waste management and composting, etc. 

I think NASA should coordinate and bid out the various proposals, build them and see what works. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/02/2016 01:10 PM
In terms of oxygen production, a Martian greenhouse that produces sufficient food to feed the population will produce more oxygen than what the colonists would consume by breathing. This is the 1st issue on the MIT MarsOne analysis, the colonists would die in a couple of months due to excessive oxygen.

There have been efforts to build a high autonomy food growing operation for Antarctica. MELISSA is actually operating in Concordia. The lunar greenhouse from the University of Arizona (at least as far as I remember from its website) is being tried at McMurdo. Now, NASA funding a self enclosed environment with food growth, something like HI-SEAS on a pressure vessel or Mars 500 with a greenhouse and a vessel? I am in favor but how would it fit within NASA's current priorities? We definitely need an experiment where even if we don't use a pressure vessel we try to see how realistic it is and how much space is needed to grow food for a small colony, but with no human mission to Mars within at least 15 years I simply do not see it happening soon. Perhaps we can convince one of the Mars advocacy simulation organization to attach this to their next Mars sim experiments. I would even be willing to help set up the experiment
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/02/2016 01:54 PM
Anything excess can be used or recycled.  Excess oxygen can be liquefied for rocket fuel.  Excess CO2, can be filtered and cracked to produce methane, or released back into the Martian atmosphere.  Excess methane can be trapped at the top of the composters and liquefied for rocket fuel.  Nothing is insurmountable with enough electrical power to operate all this equipment.  That is why I mentioned plenty of excess power for use in handling these situations. 

Power is going to be needed initially for ISRU equipment to make rocket fuel for return to earth.  It will also be needed for heating the living units, operating exploration equipment, ice mining equipment, and when greenhouses do get going, heating and lighting.  Once composting begins it can be accessed for heating, supplementing the ISRU equipment with excess methane.  I don't think there will be enough plants initially for years to produce enough oxygen for the humans to breath.  This will take trees, and large trees.  Greenhouse food production, I don't see producing enough, thus continuing to crack CO2 for oxygen.  Any excess methane could also be used for heating, cooking, or water heating.  The by-products being water vapor and CO2.  This humidity might help the humans as there is natural humidity in the air, even in the desserts on earth.  Excess CO2 can be handled as mentioned.  Also, some plants need the humidity. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/02/2016 03:11 PM
Mature trees are NOT very efficient photosynthesizers, far from it. A field with plants in their vegetative or reproductive stage has higher Net Primary Productivity than a forest. If you look a few pages back at the UA Lunar Greenhouse video or go to the website the greenhouse that produces half the food a traveler needs will also produce ALL the oxygen for breathing needs. How much food will be locally produced as opposed to being carried from earth is an issue of logistics: the average American consumes 1 short ton of food per year. Considering the 26 month launch window, that food degrades in radiation even when processed and landing weight limitations the answer becomes a balance of what can we bring (meat) as opposed to growing locally.

There is a rather interesting article today, an interview with a Utah State University professor:
http://www.utahbusiness.com/reaching-stars-utah-scientists-contributing-space-research-eye-colonization/
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 02/02/2016 04:28 PM
Years ago I saw a design for a Mars greenhouse designed specifically to put Oxygen onto the atmosphere.
It was full of trees ( cannot remember the species ).  It had an opening at ground level on one end and another at the top on the other end.  Atmosphere entered at the bottom, was converted by the trees to O2 which naturally rose up and left via the top opening.  No moving parts.

Is this design workable/ useful with regards to producing Oxygen for consumption ?

Ok to be clear was this INSIDE a Mars base/colony or outside? The former is possible, but you wouldn't use trees but something like a "living machine/wall" to keep the interior air clear/clean. The latter is not possible as any plants would freeze and the heating cost of such an "open" structure would be far to high.

The Lunar Reclamation Society (aka Moon Miners Manifesto) did a lot of work/articles on such living walls as modular and interior living machines to both regenerate air and provide visual relief in the interior of a base/colony.

AegeanBlue: It's called "urban homesteading" these days and it often incorporates high-intensity soil-less or mixed (aquaponics) growing systems much to the chagrin of "true" eco-farmers and homesteaders. Nice article by the way as it points up why aeroponics is the preferred growth method in microgravity :)

spacenut: NASA actually has numerous on-going contracted and in-house experiments going on all the time regarding bio-based regenerative as well as mechanical and chemical life support systems. In general high-intensity gardening will produce MORE food than can be consumed as well as more oxygen. You end up storing both for "lean" times or cyclic needs. And as a note but trees do not produce all that much oxygen on a world wide scale. Most of it's produced by algae and plankton which is probably what will be the primary source for space operations with growing food a secondary source.

You can in fact produce a fully automated growing system that will fit into a "standard" 40-foot ISO Container (https://en.wikipedia.org/wiki/Intermodal_container) but it's still not clear that full automation is desired as "people" in general are found to relax and feel "better" when exposed to growing plants. Hence the idea of the "living wall" interior modules mentioned above.

There's still "discussion" (because experimenters and garden enthusiasts NEVER engage in anything as crass as "arguments" and always discuss their opinions with logical calm and fact based assessment... :) ) on the merits of various recycling modes as anaerobic, aerobic, and composting all have their supporters but in the end what you get out the "other-end" is as usable from most suggested methods. Most work I've seen suggests that composting won't be as effective as one of the other two and that mostly because it doesn't deal well with the inclusion of "other" waste streams that the others do in fact handle.

In any case what you want as an output is pacified waste and nutrients capable of building soil with and/or feeding into your growing system in the most efficient manner. Hence the case for aquaponics combined systems but those don't handle human or other wastes so you are in any case going to need another system.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 02/02/2016 04:50 PM
There have been efforts to build a high autonomy food growing operation for Antarctica. MELISSA is actually operating in Concordia. The lunar greenhouse from the University of Arizona (at least as far as I remember from its website) is being tried at McMurdo. Now, NASA funding a self enclosed environment with food growth, something like HI-SEAS on a pressure vessel or Mars 500 with a greenhouse and a vessel? I am in favor but how would it fit within NASA's current priorities? We definitely need an experiment where even if we don't use a pressure vessel we try to see how realistic it is and how much space is needed to grow food for a small colony, but with no human mission to Mars within at least 15 years I simply do not see it happening soon. Perhaps we can convince one of the Mars advocacy simulation organization to attach this to their next Mars sim experiments. I would even be willing to help set up the experiment

You don't need a "pressure vessel" or such you just need to ensure that it simulates an "isolated" system which as I pointed out you can achieve with a positive pressure gradient inside and a sealed plastic "shell" around the unit.
(spacenut: Mars is cold but the interior of the base/colony will not be so you don't have to "simulate" the temperature because the growing unit will never see that temperature. It's a distraction and cost escalation you don't need for a successful experiment :) )

But all should be aware that this is probably something NASA can't "do" themselves, partly because it won't cost an arm and a leg :) On the converse side none of the Mars advocacy groups seem interested enough to put any money towards such low cost suggestions either because they don't "adequately simulate the Martian environment" (neither do either of the Mars Society labs but they tend to ignore this little issue) or do not "expand the knowledge base in a significant manner" (those are direct quotes btw from the MS on the rejection of the "simple" closed-loop-life-support experiments proposed to them) which could be argued  I think :)

No one involved with the Bio-sphere series is interested because the cost and effort does not "adequately support the proposed science involved" meaning that it won't bring in grants and investment in large enough amounts to consider nor can you get grants for such simplistic experiments unless you're a grade or middle school which would have serious liability issues with any such enclosed system experiments, but conversely is the accepted level of the "science and effort suggested" by the proposal. (In other words they don't expect "serious" science unless it costs serious money :) )

All indications are that this would have to be self-financed, which is the reason it has been proposed on a 'shoe-string' budget BUT because of that factor it looks like no would take any results seriously...

Randy
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/02/2016 10:49 PM
Most Americans are accustomed to eating meat at almost every meal.  Beef, pork, chicken, eggs, turkey, fish, shellfish, and sometimes lamb and rabbit.  America also has about 20 million hunters who bring home deer, elk, moose, and various small game such as rabbits, quail, dove, and squirrels.  Now, most of the original colonists will be North Americans, Europeans, or East Asians.  All eat some form of meat or fish.  Initially powdered eggs, dehydrated chicken or beef chunks can be brought.  They are light and full of protein.  Unless algae can be processed like textured soy protein or something, most people will start to crave real meat.  At some point it will have to be introduced or brought from earth.  I think it will be introduced because shipping from earth will not make as much economic sense.  Manufactured goods, tools, and equipment will be needed to expand Martian colonies.  The article you brought up was for zero g mostly, but that will only be temporary travel from earth.  Mars will have gravity, so normal plant growth can be done. 
Title: Re: Scaling Agriculture on Mars
Post by: redliox on 02/03/2016 06:15 AM
I'm frankly surprised this is a popular Mars thread, but I will admit for colonization farming does have ramifications.
Title: Re: Scaling Agriculture on Mars
Post by: MickQ on 02/03/2016 07:47 AM
To answer Randy,s question, the greenhouse I referred to was a stand alone unit, not part of a habitat.  This was 20 or more years ago so I can't recall details but the idea was for many to be spread around with the purpose of injecting O2 into the atmosphere, slowly but surely.  A non technical version of Sax Russell's little windmills.
I don't recall anything about heating though
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 02/03/2016 08:09 AM
I'm frankly surprised this is a popular Mars thread, but I will admit for colonization farming does have ramifications.

We are talking mainly about colonization. But plants, mostly herbs and vegetables are a necessary part of any long term space activity. I understand ISS crew is very happy when cargo arrives and there are a few tomatoes and bell peppers. People need that. MREs can fulfill the nutritional needs but that's not all. So even when the largest part of caloric needs are brought in from earth, plants are part of NASAs Mars plans for a reason.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/03/2016 12:25 PM
I've read one of the moral boosters for long term ISS missions is real fresh food brought from earth.  That is why for long term Mars colonization, real food will have to be grown, and real meat will have to be raised.   Also, even in India, they eat eggs and fish.  Growing plants or animals in greenhouses or habitats isn't going to be a killer.  Small animals do not take up much space like chickens, rabbits, quail.  The advantage of chickens is eggs.  Tilapia in tanks.  Algae can not only provide some synthetic food for humans, but can be dehydrated into pellets to feed chickens and rabbits.  Tilapia already eat algae in the water.  Real food to go with real vegetables like spinach, turnips, green beans, potatoes, cucumbers, onions, garlic, various herbs and spices, peas, and any number of vegetables.  All of these vegetables can be grown in small spaces.  They can be grown from human and animal compost mixed with Martian soil.  There can be a greenhouse for algae, one for fish, one for each of the various vegetables, one for chickens.  One for composting.  Some colonists will have to become farmers.  Some ice miners, some mineral and ore miners, some power grid maintenance.  Many will have to have multiple skills. 

As the colony is set up, it may take half the living units set up as greenhouses to provide all the variety of food needed to keep people comfortable.  Some initially will still have to be imported from earth, until the colony grows to be self sufficient.  In 1960 America was completely self sufficient in food production except tropical foods like bananas, cocoa, coffee, and such.  Some of these can be grown in greenhouses.  One of the largest exports of Iceland is bananas to Europe.  They have so many volcanic hot springs that they grow banana trees in greenhouses for banana exports. 

Scaling of agriculture on Mars yes will begin with algae, but will and must grow way beyond that for a thriving colony. 
Title: Re: Scaling Agriculture on Mars
Post by: J-V on 02/03/2016 12:35 PM
One of the largest exports of Iceland is bananas to Europe.  They have so many volcanic hot springs that they grow banana trees in greenhouses for banana exports. 

Seems to be a myth: https://en.wikipedia.org/wiki/Banana_production_in_Iceland
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/03/2016 01:02 PM
People are creatures of habit and when they move they try to reproduce the diet they are used to. However there are always practical limits. The meat heavy US diet, which is also common in other parts of the New World, is due to the low density of human settlements in the US compared to the massive cropland. There are huge ranches out west the size of entire countries with grazing animals (mostly cows) subsisting off the land. Simply put this is not Mars. High density animal production in CAFOs in a densely populated environment is very possible, see for example Europe. However it leads to a huge range of environmental and logistics issues. Also super markets have desensitized us from the annual cycles of animal growth, simply put all meats all the time is impossible without a huge undertaking. Is meat possible in a non terraformed Mars? Yes, even desirable at times. However moving from 10% of annual diet to 25% can easily mean quadrupling the plant growth area (and by that I include algae) just to provide feed for the animals, with human population stable. Is that desirable? I think not, but I am not the decider.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 02/03/2016 01:38 PM
Is meat possible in a non terraformed Mars? Yes, even desirable at times. However moving from 10% of annual diet to 25% can easily mean quadrupling the plant growth area (and by that I include algae) just to provide feed for the animals, with human population stable. Is that desirable? I think not, but I am not the decider.

I believe that meat consumption may be higher than it should be for many reasons. I believe though, that algae production on Mars is so much more efficient than growing higher plants that producing meat with algae and methane bacteria protein may well be competetive with production of food calories from higher plants. Food directly from algae is obviously more efficient and will IMO produce most of the consumed calories but it will not be all the only food besides vegetables.

The efficiency of algae comes from two sources. One is the efficiency of algae as such. The second and IMO more important is that they don't need complex setups like greenhouses. They grow in pipes that can be produced at a fraction of the cost of greenhouses.

Lots of trades in this though so in the end only real engineering can give us the numbers and influence the decision.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/03/2016 02:20 PM
Who is going to colonize Mars?  Meat eaters from the western world.  Have you guys tried to eat only algae based food?  Have you tried to eat a very restricted diet you are calling for?  Try it for 6 months, a year or two.  Ask some astronauts who have been at the space station?  They loved having pizza delivered on one of the supply ships, and fresh fruits and vegetables.  I have agreed with you concerning algae as a base food, especially for feeding tilapia and maybe chickens, or even some type of synthetic food for humans.  Ask some guys in the military about MRE's.  My son was in Afghanistan, and he HATES MRE's, especially when you have to eat them for LONG periods of time. 

This a topic of "Scaling Agriculture on Mars".  It will start with algae, then food plants, then tilapia, maybe catfish, chickens, and so on as the facilities can be built.  I think if SERIOUS colonization of Mars is done, animals will be brought there, especially small animals for food.  China is very densely populated and they eat meat an average of 2-3 times a week, mostly chicken, pork, and fish like catfish.  Europe is also very densely populated when you look at the size of the area (about the size of the US) excluding Russia, with twice the population.  They eat a lot of meat.  They eat chickens, pork, rabbits, lamb and beef sometimes.  The only country I know of that doesn't eat a lot of meat is India and they eat eggs and fish. 

I know today people are far removed from farm life.  I am 62 and my grandparents raised chickens for meat and eggs.  I have killed, plucked, and cleaned chickens.  I am also a hunter and have processed my own deer.  I also fish, and clean my own fish.  It is not hard.  Smelly and dirty sometimes, but all the waste can be processed with the human and animal wastes for compost.  Animal waste from cleaning can also be dehydrated and process to feed some small animals like pot bellied pigs and even chickens.  Chickens and pigs are omnivores so they can eat even there own waste products.  I don't see cows coming for a while unless it is some of the miniature breeds.  Chicken excrement is only half digested.  It can be dried and fed to catfish and they have even fed it to cows after drying and coating it with molasses. 

There are a lot of things that can be done.  Mars isn't like limited spacecraft in transit.  It is a wide open planet.  Greenhouses can be built everywhere or anywhere, but will probably be built near a good water supply.  A lot of these ideas need to be tried and tested in artic regions or high cold desert regions like in northern Chile at a high altitude.  Pressurized habitats, high, dry and cold, like Mars.  Inside sealed units or even underground with lighting.  All of this needs to be tested, food grown, no outside interference.  Food will have to be grown on Mars, no doubt about it.  However, a wide variety of food, and palatable food is a must.   

People on Mars will be inside most of the time and with limited food sources they can or will get "cabin fever".  People in the Pacific northwest have a higher suicide rate than the rest of America for a reason.  It rains a lot there.  They need more sunlight and outside activity.  This could happen on Mars if "comfort food" is not provided, and at least some view of the outside isn't provided.  Also large open habitat areas might be needed to provide a release of being "boxed in".  Human also need to be exposed to some UV rays for vitamin d production and a feeling of well being.  This might be done in the some greenhouses as some plants love UV rays.  Also, know that the term "greenhouses" on Mars doesn't always mean glass enclosures with sunlight.  It can be a sealed metal habitat container with proper lighting.  I still think outside views would be nice, even if it is with the use of large periscope windows. 

I am not trying to be argumentative but realistic.  My wife once lived in Oregon, and she said most of the year was cloudy and there was almost always a misty rain, very dreary.  She loves the sunshine were we live now.  Most people on earth live in temperate areas, not extremely cold, or hot and wet rainforests, deserts, or mountains.  Most of the Martian colonists will probably also come from temperate areas, so they will want to be comfortable and see some sunshine and outdoors, even if it is a desert on Mars.  Comfort food is one way to help people feel better and happy.     
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/03/2016 03:57 PM
Suicide rates tend to be correlated with hours on sunshine per year, which is why in Scandinavian countries they are pretty high. Also they tend to be correlated with social and economic stress, which was why they were quite high on former communist countries during the transition. Food can help, but social interaction is even more important, which is why even the dreariest places in Southern Europe tend to have a lower rate than the sunniest places in Northern Europe: South Europe is more collective in outlook than North Europe with all the social interactions and solidarity it entails.

Studying at Virginia Tech for 4 years I was struck by how many vegetarians we had. I am not talking about Indians or others who are vegetarians for religious reasons, I am talking about full blooded Americans who refused to eat meat for ethical (very typical among Fisheries and Wildlife Department students) or environmental reasons (especially Environmental Science students). The local watering holes always had vegetarian and vegan options on their menu.

I know it is super frustrating to be vegan for a time, I fast during the Great Lent, all 7 weeks looking forward to the skewered lamb at the end. However let's be honest, the first people to settle Mars will be more like monks than lay people, committed to a cause enough to be willing to sacrifice their comfort. Meat will come, I am in total agreement, my disagreement is on how fast. But let's cross that bridge when we get there.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/03/2016 06:18 PM
I've always though colonists would be a lot of married couples since more women are getting education these days.  I also know that most vegans tend to be women.  Men need more calories and have more muscle mass than women and need more protein thus tend to be meat eaters.  I also think the amount of outdoor activity and sunlight tends to help mood.  That may also be why the southern Europeans have a lower suicide rate.  It will take some strong willed people to colonize Mars. 
Title: Re: Scaling Agriculture on Mars
Post by: redliox on 02/03/2016 07:06 PM
Who is going to colonize Mars?  Meat eaters from the western world.  Have you guys tried to eat only algae based food?  Have you tried to eat a very restricted diet you are calling for?  Try it for 6 months, a year or two.  Ask some astronauts who have been at the space station?  They loved having pizza delivered on one of the supply ships, and fresh fruits and vegetables.  I have agreed with you concerning algae as a base food, especially for feeding tilapia and maybe chickens, or even some type of synthetic food for humans.  Ask some guys in the military about MRE's.  My son was in Afghanistan, and he HATES MRE's, especially when you have to eat them for LONG periods of time. 

This a topic of "Scaling Agriculture on Mars".  It will start with algae, then food plants, then tilapia, maybe catfish, chickens, and so on as the facilities can be built.  I think if SERIOUS colonization of Mars is done, animals will be brought there, especially small animals for food.  China is very densely populated and they eat meat an average of 2-3 times a week, mostly chicken, pork, and fish like catfish.  Europe is also very densely populated when you look at the size of the area (about the size of the US) excluding Russia, with twice the population.  They eat a lot of meat.  They eat chickens, pork, rabbits, lamb and beef sometimes.  The only country I know of that doesn't eat a lot of meat is India and they eat eggs and fish. 

Lord knows I'm trying to eat tofu on a regular basis so I understand the importance of "comfort food"...or in this case genuine meat specifically.

I don't think it will be easy raising animals on Mars, and by that I mean consider this: NASA already has a large amount of guidelines and concerns sending humans on short term missions.  Monkeys were briefly sent into space, but beyond them the most complex life otherwise sent into orbit wasn't even a rabbit but guppy fish.  Can you imagine how complicated things will get if the EPA or, say, the Humane Society steps in when animals get sent up to be eventually eaten?  Could you imagine if e.coli or salmonella mutates from radiation on a space farm?

While that expresses the complications of animal farming in space, I'll express my other opinions on it.  It wouldn't be a bad idea to bring some meat animals to Mars, especially since it'll be more Earthlike versus Luna (where the stuff could just be sent from Earth for simplicity anyway), but just like humans they're going to be confined to 'tin cans' for a long time.  Point being: it's going to be a limited selection.  Like heck we'll be seeing sheep or cows roaming under impossibly large domes.

After farming plants, aquaculture is the next obvious possibility, but I keep hearing mixed results from fish farms - basically a farmed fish is less healthy than a wild one, even taking account into mercury poison ect ect; there may be issues with the farmed fish being less tasty than frozen "Earth raised" fish.  Still fish are easier to contain than cows, and we may be able to harvest critters ranging from prawns to salmon while establishing a mini-ecosystem within a habitat to boost morale.

A chicken and a rabbit are probably the biggest animals to expect realistically.  Both can be caged, reared, and tamed easily.  A complication may be how to transport them humanely to Mars; picture an angry chicken loose in a floating environment with eye-pecking and chicken **** flying through the air.  On Mars one more complication: chickens could actually fly in the lower gravity there, so they definitely need to stay penned (in 3 dimensions).  I don't know if chicken eggs or rabbit embryos could remain viable for months, although perfecting such a method would be a precursor to cryogenic sleep for humans.

Martian farming is a good idea, but I say expect it to remain small scale for a few decades.  Lots of greens, some fish, and a little chicken would be the future diet.  For a settlement ~15 years after the first landing I'd expect the following: a slightly large glass-lined greenhouse (possibly built as a archetype for native-made resource utilization) supplemented by an underground one (either a cave or a buried module), an 'aquarium' module for viewing, harvesting, and water/nutrient recycling, and a pen for a family of bouncy rabbits plus one hen named "Angry Bertha."
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 02/03/2016 07:57 PM
In terms of oxygen production, a Martian greenhouse that produces sufficient food to feed the population will produce more oxygen than what the colonists would consume by breathing. This is the 1st issue on the MIT MarsOne analysis, the colonists would die in a couple of months due to excessive oxygen.
Anything excess can be used or recycled.  Excess oxygen can be liquefied for rocket fuel.

Separating excess oxygen from a nitrox atmosphere is cumbersome and energy hungry. You'd be better off with a biological system like fungi or yeast. Consumes excess oxygen, adds edible biomatter.

Other gases, water/CO2/Methane/etc can be much more easily separated.

(Although I doubt it would ever be worth separating trace methane from breathing air to add to the fuel production (or for cooking). The extraction and concentration equipment will be deeply different from the primary fuel production equipment, and useless for any other task. Extra specialised equipment adds cargo-mass but also man-hours for maintenance. Methane from composting would likely just be channelled into a CHP generator.)

(spacenut: Mars is cold but the interior of the base/colony will not be so you don't have to "simulate" the temperature because the growing unit will never see that temperature. It's a distraction and cost escalation you don't need for a successful experiment )

Actually, if you are simulating a classic greenhouse (ie, one using natural sunlight rather than an underground grow-room using synthetic light), you will want to also simulate the thermal effects. Both the net temperature flows at different times of day/night, summer/winter, and variable winds, but also the thermal gradient across the greenhouse itself. (How close to the greenhouse walls can the plants be grown?)

However, you probably don't have to simulate both at the same time. And much of the thermal stuff can be modelled on a computer. (Although I can't see that anyone has, which is odd.)

Greenhouses can be built everywhere or anywhere

The kind of closed loop greenhouses necessary on Mars will be high-maintenance. You will not be building more than you need.

I'm frankly surprised this is a popular Mars thread, but I will admit for colonization farming does have ramifications.

We only post when we're hungry.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/03/2016 08:33 PM
Yep.  I read a few years ago in a Popular Science or Popular Mechanics magazine an article on some self sufficient homesteads they were trying in England.  They used a methane digester for human waste.  Human waste alone produced enough methane to run a gas stove in the home.  They used solar water heating and hot water heating for the home.  Solar panels and small wind turbans were used for the electricity for lights, refrigerator and a few other appliances.  I think it was a 12v system used in RV's.  The homesteads were on the western coastal area which had a constant wind supply for producing electricity.  Now, each homestead was about 2 acres (American or English) not hectares.  Families grew chickens, a goat or Jersey cow for milk, gardens, and fruit trees.  This allowed for self sufficiency and still allowed one family member to work a 40 hour week job.  I don't remember how it worked or what families volunteered for the project.  The homes were only about 1,000 sq ft, which is very small by American standards or an average 1,800 sq. ft., but about average for English standards. 

The point I am making is a small area can produce a lot of food.  Above mentioned was totally dependent on the weather.  Inside a greenhouse, seasons do not matter, at least 4 crops of food can be grown a year. Most gardens have around a 90 day growth from seeds to harvest. 

I am thinking Bigelow 2100 units modified with one side flat for use on Mars could grow a tremendous amount of food.  Even 330 modules make with one flat side could make a village of greenhouses for any number of various food production.  In a 6' x 12' space I grow enough green beans for my wife and I for a year.   

Oh, chickens can fly on earth and roost in trees if you have free range chickens like my grandfather.  Certain meat producing chickens cannot fly.  If my grandfather wanted to fence them in a yard, especially when they have chicks, you must routinely clip their wings.  Also, sometimes the trim their beaks to avoid pecking.  And yes they would be kept in cages on Mars with nests near the outside to obtain the eggs without going into the cage.  Chicken manure is also 50% undigested and can be used over catfish tanks to feed the catfish as is done in China.  Auburn University took chicken manure, dehydrated it, made pellets and coated it with molasses to feed cows.  So anything is possible. 
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 02/03/2016 09:08 PM
(spacenut: Mars is cold but the interior of the base/colony will not be so you don't have to "simulate" the temperature because the growing unit will never see that temperature. It's a distraction and cost escalation you don't need for a successful experiment )

Actually, if you are simulating a classic greenhouse (ie, one using natural sunlight rather than an underground grow-room using synthetic light), you will want to also simulate the thermal effects. Both the net temperature flows at different times of day/night, summer/winter, and variable winds, but also the thermal gradient across the greenhouse itself. (How close to the greenhouse walls can the plants be grown?)

However, you probably don't have to simulate both at the same time. And much of the thermal stuff can be modelled on a computer. (Although I can't see that anyone has, which is odd.)

Well for one thing any "unground" grow room does NOT require artificial light and about the only group that's done any actual work on "natural" but in-direct lighting is the MMM/LR group as everyone else seems fixated on "normal" greenhouses of some type despite the obvious issues :)

Seriously, an enclosed area with "light-tubes" or in-direct optics reduces your construction and maintenance issue by an order of magnitude, (no worries about your thermal gradient or effects as the whole "module" is insulated and temperature controlled) but for some reason everyone assumes that artificial lighting will be required. Supplemental lighting will be welcome but it's not required as long as you can port the light in.

The main reason you haven't seen any good information on simulated or experimental "greenhouses" is because most research is aimed at controlling as many of the variables as possible which precludes (usually) an actual "greenhouse" (and all the thermal and other variables THAT implies) or "natural light" as those are easily controlled variables. Hence most 'serious' work goes on in temperature controlled and artificially lit laboratories.

As you note, if you're going to "test" the whole greenhouse assumption you now have to control all the external variables and "simulate" conditions on Mars or where-ever at the difficulty and expense that implies. Otherwise your data is based on a typical "Earth" greenhouse with implied assumptions on how it's insulated and environmentally controlled while still letting in sufficient natural light etc.

Places that use earth-sheltered or partially buried "greenhouses" don't need supplemental lighting because they are "buried" if they have light access and produce just as much (if not more) than a "traditional" greenhouse but the traditional is easier (and usually cheaper) to build. On Earth at any rate.

Quote
Greenhouses can be built everywhere or anywhere

The kind of closed loop greenhouses necessary on Mars will be high-maintenance. You will not be building more than you need.

Well the key word is "need" probably :) As I noted the main life support probably won't be what is grown for food or comfort but "down-and-dirty" high intensity algae set ups while "other" plants are grown around the habitat for indoor air pollution and moral purposes with food production being their own units.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 02/04/2016 08:16 PM
Seriously, an enclosed area with "light-tubes" or in-direct optics reduces your construction and maintenance issue by an order of magnitude, [...] Supplemental lighting will be welcome but it's not required as long as you can port the light in.

This has been discussed before. Light-tubes bring relatively low level illumination into dark buildings, to replace/supplement artificial lighting at normal human work levels. Such as a 60W bulb or two in a kitchen. They do not replace a 600W grow-light (or two) in the same area.

To increase the light "density", you need an external collector/concentrator for each light-pipe, and solar-collectors do badly with indirect lighting; much worse than modern solar. On top of that, you'll need a full-blown sun-tracking system.

Not seeing how you are "reduc[ing] your construction and maintenance issue by an order of magnitude".

And all that is just to replace a thin-film solar array and some tuned LED grow-lights? A solar array which produces power that can be used for anything, and hence backs up your other solar power systems, not just a single-purpose lighting system.

[As a bonus, artificial lighting greatly increases the yield for intensive hydro/aeroponics crops by exceeding natural light patterns. For eg, 18hr/day lighting during the growth phase, then 12hr/day during fruiting/seeding. Until you have ISRU-hab construction, you are going to be extremely volume limited (and even when you have ISRU-hab construction, you are still going to be volume-economical.)]

Light pipes for the general hab areas makes sense, but not for the grow-modules.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/04/2016 08:36 PM
I also think fish, tilapia, will be the first meat raised in tanks on Mars.  Eggs can be taken in transit, or the fish themselves.  They eat algae, thus converting algae directly to meat.  My son was taking aquaculture in college, and he said they are combining hydroponics with aquaculture using tilapia.  The tilapia waste is used a fertilizer for hydroponic vegetables, thus cleaning the water before returning to the tanks. 

Another thing I saw was the Chinese were raising chickens in cages over catfish tanks.  The catfish at the chicken waste, but the water still had to be cleaned and was used to fertilize gardens downstream while fresh water was coming in.  This could also be pumped back to a hydroponic garden. 

I don't think it would take a lot of work to keep up a system like this.  Fish will be taken when large enough to eat.  Chickens can be tagged and when they stop laying or decrease laying, they can be eaten.  Vegetables can be continuously harvested and replanted as used. 

Now, fish will need a place to breed, like a shallow area in a tank with proper structure.  Chickens can be culled from chicks in a couple of months, keeping one rooster per 10-12 hens for reproduction.  Large strong hens can be allowed to nest for new young.  OR, fish and chickens can be artificially inseminated.  May be harder for fish. 

After hydroponics, and a supply of compost is made, it could be mixed with Martian soil for plants that do not do so well with hydroponics. 
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 02/04/2016 09:46 PM
Seriously, an enclosed area with "light-tubes" or in-direct optics reduces your construction and maintenance issue by an order of magnitude, [...] Supplemental lighting will be welcome but it's not required as long as you can port the light in.

This has been discussed before. Light-tubes bring relatively low level illumination into dark buildings, to replace/supplement artificial lighting at normal human work levels. Such as a 60W bulb or two in a kitchen. They do not replace a 600W grow-light (or two) in the same area.

To increase the light "density", you need an external collector/concentrator for each light-pipe, and solar-collectors do badly with indirect lighting; much worse than modern solar. On top of that, you'll need a full-blown sun-tracking system.

Not seeing how you are "reduc[ing] your construction and maintenance issue by an order of magnitude".

And all that is just to replace a thin-film solar array and some tuned LED grow-lights? A solar array which produces power that can be used for anything, and hence backs up your other solar power systems, not just a single-purpose lighting system.

[As a bonus, artificial lighting greatly increases the yield for intensive hydro/aeroponics crops by exceeding natural light patterns. For eg, 18hr/day lighting during the growth phase, then 12hr/day during fruiting/seeding. Until you have ISRU-hab construction, you are going to be extremely volume limited (and even when you have ISRU-hab construction, you are still going to be volume-economical.)]

Light pipes for the general hab areas makes sense, but not for the grow-modules.

Specifically, I keep bringing it up for those who insist on "natural" lighting since that's generally a "factor" in proposing a "greenhouse" in the first place :) Secondary (as you note) light pipes in the hab areas will be a helpful factor along with the afore mentioned "periscope" windows because ANOTHER generally accepted "factor" is giving the people inside an view outside to keep them from going cabin-crazy. Areas that are NOT primary life support or food growing areas can have light tubes (pipes) focused on indoor growing areas (they will have some if for nothing else but to break up the "industrial" feel of the hab) to enhance the "outdoors" feeling of the area.

In other words I'm generalizing to avoid another "greenhouse" versus "grow module" argument but YOU blew that out of the water ;)
(At this point I really don't see that happening BUT I wanted to make it clear that even a fully enclosed module does not "require" dedicated lighting though for all the reasons you stated they would be more efficient)

I also think fish, tilapia, will be the first meat raised in tanks on Mars.  Eggs can be taken in transit, or the fish themselves.  They eat algae, thus converting algae directly to meat.  My son was taking aquaculture in college, and he said they are combining hydroponics with aquaculture using tilapia.  The tilapia waste is used a fertilizer for hydroponic vegetables, thus cleaning the water before returning to the tanks. 

Another thing I saw was the Chinese were raising chickens in cages over catfish tanks.  The catfish at the chicken waste, but the water still had to be cleaned and was used to fertilize gardens downstream while fresh water was coming in.  This could also be pumped back to a hydroponic garden. 

I don't think it would take a lot of work to keep up a system like this.  Fish will be taken when large enough to eat.  Chickens can be tagged and when they stop laying or decrease laying, they can be eaten.  Vegetables can be continuously harvested and replanted as used. 

Now, fish will need a place to breed, like a shallow area in a tank with proper structure.  Chickens can be culled from chicks in a couple of months, keeping one rooster per 10-12 hens for reproduction.  Large strong hens can be allowed to nest for new young.  OR, fish and chickens can be artificially inseminated.  May be harder for fish. 

After hydroponics, and a supply of compost is made, it could be mixed with Martian soil for plants that do not do so well with hydroponics. 

Which is why I keep bringing up aquaponics :) I've read on some aquaponics forums that it's possible to run the fish/chicken waste water through a set of "hardy" plants then through normal grow beds.

As for meat, well I'm hoping for "carneculture" vats to grow meat simply because I'm squeamish in general and hated working with the chickens, rabbits and pigs on my relatives farms :) I remember the L5-ers were pushing Guiney Pigs and Rabbits for meat production but the amount of processing for the amount of meat was always a bit iffy IMO.

I probably asked this before but why the concentration on composting over other methods? I can see some advantages for soil building but not really enough to not use a more efficient waste processing method.

Randy
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/04/2016 10:09 PM
At some point, grain crops will need to be grown like wheat, corn, and rice.  This is where martian soil might have to come into play mixed with excess compost not used to feed fish or vegetables.  Now, I've read that a 60' x 60' field can actually grow enough wheat (on earth) for a family of 4 for enough bread for a year.  That is not that much space, on earth anyways.  This is where down the road, larger greenhouses will have to be built.  Also, all animal processing waste can be reused.  Some to be dehydrated and fed to fish, chickens, or pigs.  Bones can be made into bone meal for plant fertilizer.  A lot of things will have to eventually be done for a healthy and satisfying life for humans on Mars.  Algae and processed plants will not get it for long periods of time, people will want a more varied diet.   I do eat eggs every morning for breakfast.  Sometimes over easy, sometimes poached, sometimes boiled, sometimes scrambled, but never the same for long periods.  Sometimes with bacon, sometimes sausage, sometimes with grits, biscuits, or toast.  Therefore it doesn't get boring.  Hamburger can be used not only for burgers, but for hamburger steaks, meatloaf, tacos, burritos, on pizza, in chili, in vegetable soup, in baked beans.  Thus, never boring.  I also don't eat green beans every day, nor peas, nor cabbage, nor other vegetables.  Unless algae can be made into a large variety of artificial foods and palatable, it will get boring real fast.  Other foods will be needed. 
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 02/05/2016 07:17 AM
At some point, grain crops will need to be grown like wheat, corn, and rice.  This is where martian soil might have to come into play mixed with excess compost not used to feed fish or vegetables.  Now, I've read that a 60' x 60' field can actually grow enough wheat (on earth) for a family of 4 for enough bread for a year.  That is not that much space, on earth anyways. 

The efficiency of algae is vastly superior on Mars as it needs so much less infrastructure. I think once growing sufficient amounts of grains becomes possible, martians will be so much used to algae products they won't want grains any more except for exotic specialty food maybe.

Unless algae can be made into a large variety of artificial foods and palatable, it will get boring real fast.  Other foods will be needed.

That's what IMO will happen. Food industry will provide a large variety of very palatable products. Vegetarian meat imitations are getting better fast, though many still rely on ingrediants like egg protein.

http://www.workoutplan.com/milk-made-from-algae-the-new-dairy-alternative/

Here a link from few pages upthread on algae products. Milk, egg, flour substitutes. That's only a start. It can become only better with time. I see a new profession on Mars. Food designers that create new tastes. Some as imitation of existing products, some new designed tastes. Maybe they can export the recipies to earth.

That would be sausages and pies. What's still lacking is texture. Some meat products will still be desired for texture unless vat grown meat can provide that.

Edit: Fixed typo
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/05/2016 02:22 PM
A PET greenhouse in Athens in March can easily get 40 C inside during the day if we don't keep windows and doors are not open. Since this is too hot for the plants, we usually do keep them open. PET is pretty transparent to IR radiation, it's that the closed space effect that is pretty strong. I am not sure of what is the radiation intensity of Athens in March, my guess would be ~800 W/m2 compared to the Martian 619 W/m2. Be aware also that the near vacuum of Mars' atmosphere means that heat losses from a surface greenhouse will be quite low. Of course the surface temperature of Mars except in the middle of summer is far lower than that of Athens in March. Then again I am under the impression that we can send to Mars far superior cover material than PET. I do not know how to design a pressure vessel and what it would mean in terms of transmittance. I know that the ISS cupola took quite a bit of effort to create because exactly of its extended use of windows in a pressure vessel. Heat gradients is something we actually look forward to in greenhouses because it allows natural circulation of air inside a greenhouse and reduces the need for forced air circulation. Another thing to note about greenhouses is that they are highly corrosive environments, if we go towards a completely artificial system be aware that lights, metal surfaces, walls, everything in general will corrode far faster than the rest of the habitats due to the hot and humid conditions.

When reading the grow one crop and use artificial additives comments I wonder: what is the whole production chain that goes to create these sweeteners? Do we have any petroleum or trees on Mars to create artificial vanilla for example? Will we have the machinery and precursor materials that are needed to create the substances? Creating artificial additives is like producing medicines but on a larger scale. We will need a whole logistic chain just to keep the machinery functioning. The same goes to several other things suggested here. Mix manure after treatment with molasses? OK, where will molasses come from? On earth it is a byproduct of sugar refining. Will we grow sugar cane or sugar beets just so we can get molasses? Do we want to build a whole refinery on Mars just for the byproduct?

Animals? Sure but mostly fed with byproducts of plant production. With the possible exception of insects (alas in agronomy we mostly learn how to kill insects rather than how to grow them and eat them) it is simple very inefficient. Even with a 3 to 1 conversion ratio, which is much better for animals fed with algae than what has been achieved on earth we should note that only around 50% of fish or animal carcasses is actually edible. This already means that we need to grow 6 times the calories in feed just to get the same nutritional value in meat. Animal production and husbandry creates on its own an entirely different set of problems we do not have with plants.

A four person family fed in the UK from 2 acres? I can believe that. But will we have half an acre or 2000 square meters per person of growth room on Mars? I doubt it. The MIT study on MarsOne was that it took some 250 m2 per person to provide sufficient calories in the growth chamber. I just don't see setting 8 to 10 times the minimum space required per person for the colonists, except during expansion phases. Again take into account the whole range of ecosystem services provided by the environment on earth and the logistic chain that makes the self sufficiency possible. When Mao tried to bring self sufficiency to the farming communities during the Great Leap Forward the end result was famine. Sure, Mars colonists will be far more technically savvy than the average Chinese peasant of the 1960's, but there are major limits to self sufficiency in a technologically advanced society.

This thread is popular because everyone knows about food and has some idea how to do it.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 02/05/2016 02:40 PM
At some point, grain crops will need to be grown like wheat, corn, and rice.  This is where martian soil might have to come into play mixed with excess compost not used to feed fish or vegetables.  Now, I've read that a 60' x 60' field can actually grow enough wheat (on earth) for a family of 4 for enough bread for a year.  That is not that much space, on earth anyways. 

The efficiency of algae is vastly superior on Mars as it needs so much less infrastructure. I think once growing sufficient amounts of grains becomes possible, martians will be so much used to algae products they won't want grains any more except for exotic specialty food maybe.

Also I seem to recall a recent (last couple of years IIRC) NASA experiment where a person was sealed up in a chamber with various plant grown using high-intensity hydroponics using mostly recycled waste. (One person apparently doesn't provide ENOUGH waste it seemed :) ) In a ridiculously small space he was able to provide enough food production to support himself with a widely varied diet. One thing was he had a set of dwarf wheat that he was able to rotate through for bread every day so I doubt the amount of cited space is actually required.

Quote
Unless algae can be made into a large variety of artificial foods and palatable, it will get boring real fast.  Other foods will be needed.

That's what IMO will happen. Food industry will provide a large variety of very palatable products. Vegetarian meat imitations are getting better fast, though many still rely on ingrediants like egg protein.

http://www.workoutplan.com/milk-made-from-algae-the-new-dairy-alternative/

Here a link from few pages upthread on algae products. Milk, egg, flour substitutes. That's only a start. It can become only better with time. I see a new profession on Mars. Food designers that create new tastes. Some as imitation of existing products, some new designed tastes. Maybe they can export the recipies to earth.

That would be sausages and pies. What's still lacking is texture. Some meat products will still be desired for texture unless vat grown meat can provide that.

Edit: Fixed typo

Between tofu and raman I'm pretty sure there has been a LOT of advancement in "flavoring" technology :) And I'm pretty sure algae will be the main component of the standard life support system but in general it won't be that much more difficult to grow "crops" of food plants and things life fish or small animals (mostly fish since I lean towards aquaponics and am squeamish :) ) so while less of a "requirement" I still see it being and integral part of the colony system.

Algae's main problem for consumption is the amount of processing it takes to make it "palatable" for eating. It can be done, and has been but it's usually used more as an additive or building block and you usually need other materials for filler and fiber. Thing is we're talking about a LOT of algae from a life support system so you'll need to do SOMETHING with it on a regular basis and simply feeding it to the fish (or animals if applicable) will only go so far so I can easily see it being a "staple" of the colony diet where ever it can be crammed in :)

And yes I can see "Food Design" being a near-future career, not only on Mars but here on Earth as well :)

Randy
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 02/05/2016 02:56 PM
@AegeanBlue

You raise a lot of valid points. It is going to be complex. That is why I am in constant dispute with people who believe 100 people, a 3D-printer  and a 100m² greenhouse are all it needs to have a self sustaining colony.

Yes, I am slightly overstating. :) Some argue a miracle machine providing all needs and one person is all it takes.
Title: Re: Scaling Agriculture on Mars
Post by: RanulfC on 02/05/2016 04:17 PM
@AegeanBlue

You raise a lot of valid points. It is going to be complex. That is why I am in constant dispute with people who believe 100 people, a 3D-printer  and a 100m² greenhouse are all it needs to have a self sustaining colony.

Yes, I am slightly overstating. :) Some argue a miracle machine providing all needs and one person is all it takes.

Overstating? More like under buster, why it's a requirement that there be several XBOXs and a dedicated Steam download channel to Earth otherwise every one would get bored! Yeesh, such inaccuracies :)

Randy
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 01:30 AM
Plant protein would be more efficient than raising animals for meat,

More efficient, but not fulfilling all human needs efficiently.
...
Pretty much flat wrong here. Animals produce zero protein. They only convert plant protein and lose efficiency.

Now human /wants/, sure. I buy that. Tasty bacon is tasty. But let's not kid ourselves that animal food is more efficient at providing human needs when you're already having to grow crops to feed to the animals. If the animals instead were grazing on Martian fields of lichen or something, then yeah, animals might be more efficient (since humans can't eat lichen), but that's not what we're talking about.

Plants are more efficient. Algae and other single-celled food sources are more efficient still, and I would expect them to provide the vast majority of calories for our Martians until Mars becomes very, very rich and/or terraformed.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 02/12/2016 01:47 AM
Woosh.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:18 AM
FWIW, Soylent 2.0 (the kind that comes in bottles) now has 20% of its calories from genetically engineered algae that grows in bioreactors (the algae oil has VERY low saturated fats, can even have zero saturated fats). The founder wants to eventually produce ALL ingredients from a single, engineered microalgae in photobioreactors using air (CO2, N2), water, and light (plus small amount of minerals), bioreactors perhaps small enough for everyone to have one in their home.

The founder calculated that the city of LA (4 million) could be fed by a 100,000 square foot warehouse.

So we have protein produced in vats (mycoprotein that feeds on simple sugars and single-celled bacterial protein that feeds off of natural gas) and oils produced in vats (microalgae, a little from that single-celled methane-eating bacteria). Sugars could also be produced by cyanobacteria (is done industrially on a pilot scale plant from a company called Proterro... in photobioreactors like Soylent plans to use), and more complex carbohydrates could be formed in a similar manner. So all the pieces are basically there for producing the main macronutrients in vats using either methane (which is going to be synthesized on Mars anyway) or light as the ultimate source of energy. Soylent just wants to do this all in a single organism and in a health-optimized way (i.e. few simple sugars, etc).

Microalgae is probably a good candidate for this.

...but I'm actually a fan of methane or hydrogen-eating bacteria, since I think the round-trip efficiency can be higher. You're looking at 3-7% energy efficiency of light to food energy for microalgae and cyanobacteria (though you could raise that by using only certain wavelengths) and an electricity-to-light efficiency of 30-50% (though you COULD just pump the cells through insulated tubes on the Martian surface to collect Martian sunlight directly) for a round-trip of at best ~3%, versus like 17% energy efficiency of methane to food energy for methanotrophs, and methane could be produced up to 70% efficient (if you recover heat from Sabatier Reaction and use high efficiency hydrogen electrolysis) for a total of 12% electricity to food energy, about 4x as efficient if you're starting with electricity production.


Since a 2000kcal daily diet works out to ~100Watts, that means that food energy can be produced for as low as ~800Watts per person, perhaps even lower with some cleverness. Or about 3-4kW for the electricity->LEDlight->microalgae route (though this way would be easier to in-situ produce on Mars, since the tubes could be manufactured totally in-situ easier than solar cells or nuclear power plants would be). Of course, as a byproduct you get PLENTY of oxygen.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:21 AM
Woosh.
Needs vs. wants.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 02/12/2016 02:25 AM
I think that if you expect to attract enough people to colonize Mars, you're going to have to be able to offer them more than living on algae milkshakes. Because the novelty of red alien landscape is not going to be able to overcome the algae taste for more than a few months. Sooner or later, people will want real food like what they're used to having back on Earth. Otherwise, there's going to be a high dropout rate.

People will want meat, they'll want bread, they'll want cheese, etc.

It seems like automation in agricultural cultivation is already starting to take off here on Earth, so perhaps some of that technology would be adaptable to Mars. You could grow crops in pressurized envelopes, and even livestock. It may not be as efficient as growing algae, but human beings live for more than just efficiency - we're not insects.

http://www.foxnews.com/tech/2016/02/02/farm-run-by-robots-will-churn-out-30000-heads-lettuce-day.html

The farther away from home, the more the feelings and comforts of home become precious.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 02/12/2016 02:27 AM
Woosh.
Needs vs. wants.

That irrelevant distinction you got taught in grade school? Seriously?

Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:38 AM
I think that if you expect to attract enough people to colonize Mars, you're going to have to be able to offer them more than living on algae milkshakes. Because the novelty of red alien landscape is not going to be able to overcome the algae taste for more than a few months. Sooner or later, people will want real food like what they're used to having back on Earth. Otherwise, there's going to be a high dropout rate.

People will want meat, they'll want bread, they'll want cheese, etc.

It seems like automation in agricultural cultivation is already starting to take off here on Earth, so perhaps some of that technology would be adaptable to Mars. You could grow crops in pressurized envelopes, and even livestock. It may not be as efficient as growing algae, but human beings live for more than just efficiency - we're not insects.

http://www.foxnews.com/tech/2016/02/02/farm-run-by-robots-will-churn-out-30000-heads-lettuce-day.html

The farther away from home, the more the feelings and comforts of home become precious.
Let's get one thing out of the way:

A) People who go to Mars aren't looking for luxury. Okay? Okay.

B) The most important thing is human survival as well as keeping people healthy and not hungry. People who do not have enough calories or have improper nutrition will not be having a good time, no matter if it's 100% organic free-range Mars cattle or not. If the colony cannot support its inhabitants properly, all other things are moot.

That doesn't mean we don't also eat for entertainment, but other things can substitute for entertainment/comfort. Nothing can substitute for proper nutrition and calories, because by not having enough of that, you'll be miserable pretty much no matter what. So that must be solved and solved fully and completely.

I imagine a sort of two-layered food production system on Mars:
1) food for fuel
2) food for pleasure.

Modern food processing basically can take almost industrial products like sugar, flour, oils, starches, proteins, etc, add flavors and spices and salt, and convert 1 into 2. Bread is this. tortillas, chips, cakes, meatloaf, hamburger, cheese, etc. A lot of stuff is heavily processed, and there are ways to produce it more efficiently (and we can DEFINITELY do better than "American cheese" and the typical fast-food and convenience store food that so many rely on). Lettuce and other greens are fairly easy to produce, and so we'll likely produce it even with the first missions, but it's a mistake to count on this for caloric intake. Lettuce has essentially zero calories. Even tomatoes which have non-negligible calories are tough to subsist on, though they provide a lot of flavor and are easy to grow in a greenhouse.

But we're not going to have rows of corn, wheat, soybeans, etc. These things can just as well and more efficiently be produced in vats then later processed into flour and softdrinks like we have on Earth.

The vast majority of actual agriculture by acreage is producing staples, and staples can be produced efficiently and nutritionally in vats.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:40 AM
Woosh.
Needs vs. wants.

That irrelevant distinction you got taught in grade school? Seriously?
Not irrelevant. If you don't satisfy needs like hunger, no amount of other things can substitute. If you satisfy the needs like hunger, then other things can substitute for obsessing over the perfect bottle of wine, etc. So you address basic needs FIRST.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:47 AM
People don't start riots because they haven't got enough sirloin. They start riots because they don't have enough food. If you pound that problem into the ground completely and efficiently, then you can ALSO have your sirloin.

During the Biosphere 2 experiment, this problem was NOT effectively solved. They relied on crops they grew themselves, and they failed because of that.

Growing crops and livestock should never be critical to the survival or health of the colonists. To keep social and psychological problems to a minimum, sufficient calories must be maintained in a more efficient and bountiful manner. Pressurized volume and especially pressurized lighted /area/ will be at a premium. A colony would be devoting a majority of its structure (and thus building capacity) to growing crops if it grew staples in fields instead of vats, and this would make the colony much more likely to fail, be too expensive to ever start in the first place, or be a fairly grueling affair where you're back to being unsure of your next meal.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 02/12/2016 02:50 AM
No-one's disagreeing with you. The comment that you were replying to - that you still simply fail to understand - was telling the vegan to go home.

Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:53 AM
I think that if you expect to attract enough people to colonize Mars, you're going to have to be able to offer them more than living on algae milkshakes. Because the novelty of red alien landscape is not going to be able to overcome the algae taste ...
...several problems with that statement. First, the algae can be engineered to taste however you want. In fact, algae oil has a /very/ clean test compared to other oils, not at all like "algae."

Additionally: You can grow cultured meat. You can even grow milk and eggs in a similar way, and there are several food startups doing just that.

And finally: we keep talking about pampering our Martians, not expecting them to change at all or to develop their own unique tastes given their unique environment and unique constraints. This has never been the case for any human settlement of ANY new place.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 02:54 AM
No-one's disagreeing with you. The comment that you were replying to - that you still simply fail to understand - was telling the vegan to go home.
I understood the message, and the message is both incorrect and thoughtless.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 02/12/2016 02:57 AM
And finally: we keep talking about pampering our Martians, not expecting them to change at all or to develop their own unique tastes given their unique environment and unique constraints. This has never been the case for any human settlement of ANY new place.

That's because they're not Martians yet. SpaceX's customers are going to be, predominately, Americans and it rather well off Americans at that. If you want to sell a $500k/seat product you have to lay on the caviare.
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 02/12/2016 02:58 AM
I think that if you expect to attract enough people to colonize Mars, you're going to have to be able to offer them more than living on algae milkshakes. Because the novelty of red alien landscape is not going to be able to overcome the algae taste ...
...several problems with that statement. First, the algae can be engineered to taste however you want. In fact, algae oil has a /very/ clean test compared to other oils, not at all like "algae."

Additionally: You can grow cultured meat. You can even grow milk and eggs in a similar way, and there are several food startups doing just that.

And finally: we keep talking about pampering our Martians, not expecting them to change at all or to develop their own unique tastes given their unique environment and unique constraints. This has never been the case for any human settlement of ANY new place.

I'll argue that in all cases where people have moved to settle new lands they've done so in the belief that they would be improving their lives and their childrens prospects, it doesn't sound like that's what even you are expecting on Mars.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 02/12/2016 03:02 AM
I'll argue that in all cases where people have moved to settle new lands they've done so in the belief that they would be improving their lives and their childrens prospects, it doesn't sound like that's what even you are expecting on Mars.

Sure, but it's completely subjective. Israel comes to mind. People flocked there for a chance to control their own destiny, and enact their common interest. I think the Elonites will be much the same.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 03:04 AM
And finally: we keep talking about pampering our Martians, not expecting them to change at all or to develop their own unique tastes given their unique environment and unique constraints. This has never been the case for any human settlement of ANY new place.

That's because they're not Martians yet. SpaceX's customers are going to be, predominately, Americans and it rather well off Americans at that. If you want to sell a $500k/seat product you have to lay on the caviare.
You don't seem to understand that this would vastly increase the necessary volume per person for the colony and would make self-sufficiency much less likely.
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 02/12/2016 03:07 AM
I'll argue that in all cases where people have moved to settle new lands they've done so in the belief that they would be improving their lives and their childrens prospects, it doesn't sound like that's what even you are expecting on Mars.

Sure, but it's completely subjective. Israel comes to mind. People flocked there for a chance to control their own destiny, and enact their common interest. I think the Elonites will be much the same.

Apart from "want to go live on Mars" what are the common interests and what current threat, is faced by the "Elonites"?
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 03:13 AM
If you get half your calories from meat, that's like 20,000-40,000 square feet of agriculture to support that. Potatoes are 15-30 times as efficient, space-wise, so ~1500 square feet. Producing food in vats would be much more efficient than that, requiring negligible space per person (less than one square foot... yes, it's that productive), AND could be cultured to taste as good as the meat.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 03:14 AM
I'll argue that in all cases where people have moved to settle new lands they've done so in the belief that they would be improving their lives and their childrens prospects, it doesn't sound like that's what even you are expecting on Mars.

Sure, but it's completely subjective. Israel comes to mind. People flocked there for a chance to control their own destiny, and enact their common interest. I think the Elonites will be much the same.

Apart from "want to go live on Mars" what are the common interests and what current threat, is faced by the "Elonites"?
Common interest is the fate of humanity and the threat is that of the species being wiped out if we forever forestall that next step. Has this not been repeated enough?
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 02/12/2016 03:16 AM
what are the common interests and what current threat, is faced by the "Elonites"?

Why, of course, the dream is to be surrounded by right-thinking people who look up to the sky instead of down at the dirt. Surely you know. As for threats, they're everywhere. Anyone who doesn't understand and share the dream is a threat. The competition, the politicians, the bankers, even those people who prefer to watch football to rockets launching.

You don't seem to understand that this would vastly increase the necessary volume per person for the colony and would make self-sufficiency much less likely.

Sure, but you have to pay for it too. Self-sufficiency is a long term goal. It's something the forcing function produces.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 03:21 AM
What does it matter to the enjoyment of the food if it's cultured or raised in a pasture? Only the story that's told about it.
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 02/12/2016 03:23 AM
I'll argue that in all cases where people have moved to settle new lands they've done so in the belief that they would be improving their lives and their childrens prospects, it doesn't sound like that's what even you are expecting on Mars.

Sure, but it's completely subjective. Israel comes to mind. People flocked there for a chance to control their own destiny, and enact their common interest. I think the Elonites will be much the same.

Apart from "want to go live on Mars" what are the common interests and what current threat, is faced by the "Elonites"?
Common interest is the fate of humanity and the threat is that of the species being wiped out if we forever forestall that next step. Has this not been repeated enough?

Maybe it's just me, but that doesn't sound like the imminent threat to ones own family, or an imminent opportunity,  that would drive people to the risks and hardship that Mars appears to promise, especially to the relatively wealthy people who could afford the $500k a seat.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 03:42 AM
$500k/seat wouldn't be for the wealthy, caviar-eaters. That's the entry level price (we hope it's even lower). The caviar-eaters would pay at least twice as much as they'd be consuming twice the resources (full menu on the way there, larger space, caviar, etc). The entry level price is for middle, maybe slightly upper middle class folk (we assume some economic growth), people who sell their house, car, cash out their savings and head to Mars to live.

If you can offer a $500k ticket WITH all the amenities of the caviar-eaters, then you logically can offer a $250k ticket for those who either can't afford or don't want those other amenities.

Why is this a hard concept to understand?

Personally, I'd rather eat vegan and have room for my family than eat steak and go alone. I can't be the only one.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 03:46 AM
I'll argue that in all cases where people have moved to settle new lands they've done so in the belief that they would be improving their lives and their childrens prospects, it doesn't sound like that's what even you are expecting on Mars.

Sure, but it's completely subjective. Israel comes to mind. People flocked there for a chance to control their own destiny, and enact their common interest. I think the Elonites will be much the same.

Apart from "want to go live on Mars" what are the common interests and what current threat, is faced by the "Elonites"?
Common interest is the fate of humanity and the threat is that of the species being wiped out if we forever forestall that next step. Has this not been repeated enough?

Maybe it's just me, but that doesn't sound like the imminent threat to ones own family, or an imminent opportunity,  that would drive people to the risks and hardship that Mars appears to promise, especially to the relatively wealthy people who could afford the $500k a seat.
Jews who went to Israel post-WW2 also didn't have an imminent threat, though due to recent events they did have very good reason to believe a long-term existential threat existed.

Personally, I think the biggest threat is that our decisions will be guided solely by those who think only in terms of imminent threats and never in terms of a real positive vision for humanity. :P
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/12/2016 03:51 AM
It is not so easy to find information on Soylent and its specific manufacture but according to Wikipedia and its website version 2.0 contains products derived from soybeans and sugar beets as major components. In the future their intention is to replace them with more algae derived products that will be created somehow. The quick question is, what is the whole production process down to its component elements? Even when we are talking about algae, Carbon comes for the atmosphere and Hydrogen and Oxygen from the water, but where do the rest of the elements come from? In any case I am under the impression that maintaining growth is going to be more complex than just putting everything in a vat and keeping the lights on, my memories from microbiology class was that keeping the right species going was complex. We should not be basing an entire system on one particular startup which still needs to prove quite a bit of things. They do claim to be producing an entire complete meal solution, but do we really know what the long term effects of this diet is?

I think that the motivation of future colonists and who these colonists will be is a subject for another thread. Let me just say though that often in history colonization was a forced and not voluntary. We have no certainty who and how future colonists will get to Mars, just ideas.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 04:25 AM
Life is nearly entirely carbon, hydrogen, oxygen, and nitrogen. Nitrogen would come from the air and could be fixed either by addition of hydrogen (the very simple Haber process upon which all modern agriculture rests) or by the organism itself.

Everything else is on the order of 1% by mass (i.e. 2-5 grams, though most of the elements are only VERY sparingly needed, i.e. Milligrams), and is various salts like potassium, sodium, etc. phosphorus, sulfur, chlorine (as part of sodium chloride), and even less iron and copper, etc. all these elements can be found in the soil of Mars as various salts and could be extracted without too much trouble. In the very early days, you can easily send all these to Mars. 2 decades on Mars would require just 20-30kg of minerals per person (and FAR far less after you take care of the big ones like potassium, sodium chloride, phosphorous, and sulfur). And you can also recover these minerals by incinerating excrement and collecting the fine ash.
Title: Re: Scaling Agriculture on Mars
Post by: sanman on 02/12/2016 05:51 AM
I agree with you on the 2-tiered food production for the interim. In the early period, a colony with meager resources would be most on guard against starvation and be focused on providing the basics. But if a Mars colony ever gets a substantial economy going, I'd imagine that some people on Mars might be willing to devote themselves and their efforts towards agriculture and food - just as people have historically done on Earth - since after all, it's a fundamental human need.

If growing meat in vats is more efficient on Mars, then it would likely be more efficient on Earth too, so it's possible that the technology would be developed and refined for markets here on Earth first, and then later ported to Mars.

Necessity is the Mother of Invention. Entrepreneurial Mars pioneers might find there's a lucrative market for providing appetizing foods to others there, and apply their skills in that direction. As long as people are well-compensated for their efforts, they may find it worth their while to branch out into such specializations as agriculture and food. As time goes on, not everyone on Mars may be see their future in geology or soil analysis.

In the long run, a well-run colony will rise beyond merely guarding against starvation. A well-functioning Mars colony will likely try to generate a surplus of food and maintain a large food reserve in frozen storage. Maybe the algae stuff will be kept in frozen storage as a backup in case anything goes wrong. Here on Earth, China has a "strategic pork reserve", not because pork (low-protein meat) is fundamental to staving off starvation, but because the population have a fondness for this particular meat, so that a shortage of it could cause social unrest:

http://www.cnbc.com/id/100795405

With enough automation and planning, it may eventually be possible for a colony to strongly outperform basic food production requirements. Robotics may make it possible to achieve agricultural output that allows colonists a lot of freedom of choice, and not just an unpleasantly bare-bones healthful diet. This won't be in the early period, but in the longer run.

Even far-flung American military bases are known to have popular restaurant chain outlets within them.
Maybe there will be a McDonald's on Mars. Maybe there will even be Archer-Daniels-Midland on Mars. Maybe the private sector will put their heads together and apply their technical expertise to maintaining a token symbolic presence for their brand on Mars. The more a colony grows, the more opportunity there will be for specialization, including in food production.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/12/2016 02:22 PM
Major elements of plants are C, H, O, N, P and K, iron is intermediate and another 20 elements or so are micronutrients. The whole homesteading on Mars narrative on Mars ignores that nitrogen fixing bacteria do the transformation from elemental N2 to plant available forms in Earth soils and, simply put, Mars soils lack this ability to our knowledge. High yield agriculture in all forms depletes soil nutrients on a relatively rapid basis. Another thing about plant nutrition is that most element deficiencies are not due to lack of the element per se as much as that different elements are absorbable at different pH. With soils controlling for pH is hard because the soil itself has high pH that is difficult to modify towards 7 (though making it worse is relatively easy). With hydroponics it is comparatively easier to modify pH in the nutrient solution though other problems are known to pop up: In areas with horrible water quality such as Cyprus salts are known to precipitate as sediments not only making the element unavailable to the plant but also clogging the emitters and requiring their replacement. The main reason has hydroponics have not completely replaced soil based agriculture in greenhouses (other than monetary capital demands) is the lack of specialists to provide this kind of information to the farmers. I am not very familiar with how algae on a vat would work. I did see a few links on the internet and honestly it is a complicated setup that requires significant care:

http://www.oilgae.com/algae/cult/pbr/pbr.html
http://algae.illinois.edu/projects/biomasscultivation.html

Meat in a vat is not more efficient but rather less efficient than growing the meat on the animal and slaughtering the animal. We can build a CAFO on Mars, though as always there are several unknowns in process: How would the animals react to a year lasting twice as much as on earth?

When setting up a production system in an area as barren as Mars the question is: what are the material requirements, both initially and in the long range, to maintain this system? We do not have a hardware store to pick up stuff that breaks down. We do not have an industrial base to create large quantities of complex precursors. Resupply will most likely come every 26 months rather than continuously. Simple is better than complex even if complex is more efficient. Hydroponics is a system with over 50 years of commercial experience and known strengths and weaknesses. Food from a vat is futuristic, it has reached the pilot production phase but it still contains too many unknowns that need to be answered.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 04:47 PM
Wait, who is ignoring nitrogen fixation? For agriculture on Earth, we rely on the Haber process: hydrogen and nitrogen gas reacted to produce methane. This can certainly be done on a Mars base as both hydrogen and nitrogen gas will need to be produced anyway.

And a superorganism based on bacteria or microalgae could also fix nitrogen.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/12/2016 05:28 PM
A super rocket with an infinite improbability drive could also open the universe to exploration. There have several attempts to create superorganisms that are able to do 3-4 wonderful things at once. Even in the cases that the scientists did insert the genes and the resulting organism survived it proved not very viable. Tweaking an organism to produce a complicated organic molecule is one thing, tweaking it to produce an entire metabolic chain that does not negatively interfere with its existing internal machinery is another. Even if we do manage to produce the superorganism that is autotrophous, grows easily and produces a balance meal for humans under Martian conditions it would take quite some time to get through the safety and legislative approvals necessary for human consumption. Olestra was discovered in 1968, gained approval for human consumption as "fat free fat" in 1996. While it is still around and is available in foods you can buy at the supermarket it become rather unpopular after a few years because of its side effects. Assuming the superorganism is created in 10 years, by the time of the Mars colony it might be gaining approval to be consumed by humans on Earth.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/12/2016 07:57 PM
Cyanobacteria already fix nitrogen, produce sugars, lipids, and protein. It's already quite close to a complete food (for the macronutrients), if these are done in the right proportion. It's not at all an absurd goal, though in the end it might make sense to produce these separately using different strains.

I mean, we are talking about "scaling" architecture, i.e. A large population on Mars, a goal itself much more ambitious!
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 02/13/2016 03:51 AM
If the agriculture requires certain microbes, such as for fixing nitrogen, colonists can carry those with them and introduce them into the system.

On the issue of soil pH, I imagine microbes might be engineered to produce necessary acid.
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 02/14/2016 07:51 AM
Major elements of plants are C, H, O, N, P and K, iron is intermediate and another 20 elements or so are micronutrients. The whole homesteading on Mars narrative on Mars ignores that nitrogen fixing bacteria do the transformation from elemental N2 to plant available forms in Earth soils

I suspect that nitrogen fixing will be based on some variant of the Haber process and the use of artificial fertilisers.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/16/2016 05:54 PM
We do not need to engineer microbes to change the soil pH, they are already present in the soil. For that matter the diversity of life on soil is staggering. We can transport soil in bags to inoculate the Martian regolith inside the greenhouses. Being however in an enclosed space creates all sorts of problems to the soil. Microorgamisms unfavorable to the growth of cultivated plants can arise and dominate such closed soils in ways that it is not possible in natural open air based soil systems. We can sterilize inside the greenhouses the soil through steam sterilization, and then discover that problematic rather than beneficial organisms are the ones that recolonize the soils. It is this series of interrelated problems that led to the commercial adaptation of hydroponics beginning in the Netherlands in the 1960's. Now hydroponics is a well characterized growing system with 50+ years of commercial exploitation, multiple production systems, millions of hectares and many known strengths and weaknesses. Ignoring for the moment the plausibility of creating a super-algae, able to produce a meal that is balanced nutrition for humans, what is the level of knowledge we have for this production system? What are the issues with production of this particular algae to be engineered? What are its main pests? How viable and hardy is it, especially considering that the Martian Environment is more likely than not to be far more hostile than most earth environments? This is simply too much risk in my opinion, basing the crop system exclusively on food from a vat due to reasons of efficiency simply creates a single point of critical failure.

I agree that N will be mostly provided through the Haber process (or at most nitrogen rich rocks) rather than nitrogen fixing bacteria. It is this kind though of persistent technical complexity that makes analogies to the Conquest of West (not a pleasant experience for the conquered) irrelevant. My thinking is chemical fertilizer production first, then algae plus hydroponic plants, then algae, hydroponics and soil based agriculture after soil compost becomes available. We will need at the minimum some sort of compost to detoxify the Martian soil, even after washing it and removing perchlorates.
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/17/2016 12:26 AM
Why would you use just one "vat"? Photobioreactors are easy to have multiples of, and I'm sure that any decent colony would have many different such systems producing different foodstuffs. And the great efficiency of such production would allow enormous contingency reserves to be amassed.

We'll always want to grow stuff on Mars. But we'll likely never rely on tilling the soil to produce most of our calories on Mars. On Earth, the outdoors is huge, with LOTS of sunlight, often plenty of water and good soil already with breathable air (for both the workers and the plants). This isn't true for Mars where EVERY scrap of tilled area and air will need a whole bunch of expensive engineering and materials to build and maintain.

We will still have green spaces, fresh fruits and vegetables, but just like on Earth, our staples and the majority of our calories will be things the vast majority of people won't see produced in their day to day lives.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 02/17/2016 07:35 AM
@AegeanBlue

Your input as a specialist on agriculture is greatly appreaciated, I am sure not only by me. Lots of things I never knew.

However I get the impression you do not sufficiently appreciate that agriculture on Mars will not be done by amateurs. It will be highly trained people, though maybe mostly in other fields, with all the knowledgebase available on earth to their support. They will be able to provide plants and animals with optimized nutrients and environmental parameters and have the highest yields possible.

Probably trials will be needed to find an optimum for martian light levels. I expect mostly ambient light, maybe with added lighting for periods in growth where it brings the biggest advantage.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/23/2016 02:55 PM
I have to admit that I suffer from the agronomist's pride: Five years we are taught on campus, both inside and outside classes, that if anyone who is not an agronomist or a farmer talks about agriculture they have no idea what they are talking about. If anything commander Kelly has proven that astronauts can most certainly follow expert advise when growing zinnias, even if they are not agronomists.

NASA PR has a very interesting article, which I found at Parabolic Arc:

http://www.nasa.gov/feature/nasa-plant-researchers-explore-question-of-deep-space-food-crops
Title: Re: Scaling Agriculture on Mars
Post by: b0objunior on 02/23/2016 04:17 PM
I have to admit that I suffer from the agronomist's pride: Five years we are taught on campus, both inside and outside classes, that if anyone who is not an agronomist or a farmer talks about agriculture they have no idea what they are talking about. If anything commander Kelly has proven that astronauts can most certainly follow expert advise when growing zinnias, even if they are not agronomists.

NASA PR has a very interesting article, which I found at Parabolic Arc:

http://www.nasa.gov/feature/nasa-plant-researchers-explore-question-of-deep-space-food-crops
Kelly was following expert's advice, but the plants were not doing very good, so he decided that he should by himself take care of the watering on a day to day basis. So when he followed the experts completly the plants were doing worst then when he did not.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/23/2016 06:26 PM
My understanding was that the zinnia plants caught a mold infection. He asked the experts, they told him reduce humidity, he had the fans open for more time reducing humidity in Veggie and the fungus receded. As a result they bloomed again.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/23/2016 10:41 PM
My grandfather had a "farm want-a-be".  He raised chickens, some peanuts (about an acre), vegetable garden, had all kinds of fruit and nut trees.  I learned gardening from him.  One can grow a lot, and I mean a lot of food (vegetables) in a small space, rotating crops, growing year round (deep south), and using cold frames or a small greenhouse in winter.  My late FIL had two small (about an acre each) fish ponds that he raised bream and catfish in.  He had more fish than the whole family could eat, and so he supplied the local county jail with fish occasionally.  Both my grandfather and my late FIL only had an 8th grade education, but they knew how to grow and raise food. 

My son is in aquaculture and has learned a lot about raising tilapia.  I know how my grandfather raised chickens as I spent every summer with him during grade school. 

Again all that being said, a lot of real food, not made from algae, soybeans, or such can be grown in small controlled spaces. 

Now, for Martian colonists, here is a potential problem if we stick with only one or two main crops (algae or soybeans).  I, and maybe many others have become in my older age, allergic to foods that I once ate all my life.  I have become allergic to soy and soy products, milk and milk products, peanuts, tomatoes, and wheat (not gluten).  I have no reason why, but I have.  This may happen to Martian colonists unless extensive family screening is done prior to going to Mars.  So, having an extensive variety of foods might become necessary over time, to avoid problems. 
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 02/25/2016 12:07 PM
I saw Dara O'Briain's program "Tomorrow's Food" yesterday:
http://www.bbc.co.uk/programmes/b06r3jh5

He reported from the Quorn factory. Apparently, Quorn is a fungus which is fermented in large vats with sugar as the primary feedstock.

Personally, I prefer real meat, but all accounts Quorn is a good substitute and could form the main source of protein - on Mars as well. The question then is where to get the sugar from?

Can sugars be built artificially from basic hydrocarbons?

Alternatively, http://www.cnbc.com/2015/05/21/could-algae-save-the-world.html
"What makes these algae very special is they're extraordinarily fast at using photosynthesis to convert carbon dioxide, salt water and sunshine into sugars," Woods said. "It does that about 50 times faster than the terrestrial normal plants we use to make ethanol."

 
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/25/2016 12:49 PM
I agree algae would be the basic beginning building block, for food and fuel, and maybe even plastics.  Like I said earlier, tilapia eat algae, so that is a direct protein conversion, with waste from processing going into fertilizers for regular soil or hydroponic plants.  Not only the fish excrements, but from cleaning the fish for food, the intestines can be dehydrated, powdered and used for fertilizer also.  After algae, tilapia, and high yielding garden vegetables, then follow with chickens and maybe catfish, then rabbits, or guinea pigs.  Chickens would produce eggs as well as meat.  Grains like wheat, corn, and rice would come later as well as maybe larger animals. 
Title: Re: Scaling Agriculture on Mars
Post by: RonM on 02/25/2016 03:32 PM
I doubt larger livestock would ever be used on Mars. It's debatable that larger livestock are practical on Earth with the amount of resources required to produce the useable calories.

Mars colonists will have to get use to fish, rabbits, and guinea pigs. Maybe chickens because they are small and produce eggs. Steak and bacon can be imported from Earth for special occasions.

I don't see grain production either, considering the amount of area that would take. Stick with algae production.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/25/2016 04:59 PM
They could make chicken bacon, like they make turkey bacon, unless turkeys are brought.  Ground chicken or rabbit could be flavored, colored, and textured to look like hamburger.  There is a small rodent from Central or South America that has the flavor of pork, but produces twice or more of the meat for the same amount of food that pigs produce.  I can't think of it's name, but it might be an optional meat producer.  Shrimp can be raised in aquariums also.  Might not be as productive as tilapia, but also an option. 

I think a variety of foods produced in various greenhouses on Mars would make for a challenging and rewarding career as a Martian farmer.  I would say probably at least half the habitat space on Mars would have to be dedicated to food production to avoid consumables being imported from earth. 

Later clothing will have to be produced, cotton? flax? synthetic fibers from algae produced petroleums?  So agriculture might need to be scaled up for clothing production after foods.  Either Martian grown or synthetics from Martian resources. 

There will need to be a lot of underground building going on to produce space for living, manufacturing, and agriculture.  This may have to be an ongoing process from day one for a growing colony.  The quicker things are manufactured and grown on Mars the faster the Martian economy can grow. 
Title: Re: Scaling Agriculture on Mars
Post by: Arb on 02/25/2016 08:02 PM
I doubt larger livestock would ever be used on Mars. It's debatable that larger livestock are practical on Earth with the amount of resources required to produce the useable calories.

Mars colonists will have to get use to fish, rabbits, and guinea pigs. Maybe chickens because they are small and produce eggs. Steak and bacon can be imported from Earth for special occasions.

I don't see grain production either, considering the amount of area that would take. Stick with algae production.

You are almost certainly mistaken because ... capitalism.

If there are colonists willing to pay for real meat (and there will be) then there will be people willing to rear it. And as rearing meat requires grass and grain that'll happen too.  Eventually.

Ditto bread.

As for chickens, have you any idea how many food products require eggs? My guess is that there will be poultry from very early days.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/26/2016 01:07 AM
About 1/2 acre or less of wheat can supply a family of 4 for a year.  Doesn't take much space for wheat actually.  In a greenhouse on Mars 2 or more crops could be grown in a year, since there will be no seasons in a greenhouse.  I don't see larger animals until large scale production of grains is accomplished.  Large herbivores can eat wheat straw, corn stalks, and such.  It isn't absolutely necessary to "fatten them up for slaughter". 
Title: Re: Scaling Agriculture on Mars
Post by: alexterrell on 02/26/2016 09:07 AM
About 1/2 acre or less of wheat can supply a family of 4 for a year.  Doesn't take much space for wheat actually.  In a greenhouse on Mars 2 or more crops could be grown in a year, since there will be no seasons in a greenhouse.  I don't see larger animals until large scale production of grains is accomplished.  Large herbivores can eat wheat straw, corn stalks, and such.  It isn't absolutely necessary to "fatten them up for slaughter". 

The Dara O'Briain program also reported from an indoor city farm in the states (New York I think), where they were growing excellent lettuce under artificial light. Yields are much higher than a farm - just as well.

Whether it's practical to grow grains - I'm not sure. The conversations above still haven't shown how algae can fully grains. As they can produce carbohydrates, it should be possible. But as grains are so cheap on Earth, there isn't much research into it.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/26/2016 01:48 PM
Monoculture has a major problem far more immediate than the emergence of allergies: Plant protection. Yes, 10 vats of algae are better than one, but if a pest or disease emerges in one vat there is a very strong probability it will emerge in the other 9. Let us not forget how closed will be the entire Martian biosphere. Polyculture is a necessary solution, algae and higher plants.

So far all the papers I have run into say that algae makes a rather inefficient feed source. Animals require twice as much algae to assimilate the same body weight than a more typical meal of cottonmeal, soybeans, corn or wheat. I doubt that algae for feed is that efficient as a solution when you consider the whole growth chain.

I am pretty sure that we will have animals, including cows, on Mars eventually. When thinking of a bovine farm do not picture the sort of open air grazing animals of the US West or the Argentinian Pampas, think of the multistory apartment complex style dwellings of high intensity European facilities. Mars animal farms will be factory farms, and take into consideration the whole range of things a factory farm requires and causes.

I doubt that that we will have 1/2 acre or 2000 m2 for a family of four on Mars. Wheat has higher yield in hydroponics, but still we would likely need higher yield horticultural crops. What we will definitely have is more than 1 crop per year, either Earth or Mars. Space will be at a premium on a Mars colony, so we will need to optimize the temporal factor, we cannot leave the greenhouse fallow for half the year. As soon as one crop is over, there will most likely follow a feast and then they'll move on to the next crop. Not to mention that it is likely that at the plant nursery the next crop will have already germinated and grown before the previous crop is over, so as to facilitate rapid turnover.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/26/2016 02:08 PM
So once one complete agricultural "city" on Mars is built, another city should be built further away and repeat the process.  That way if there is a disease affecting one city's crop, it wouldn't or shouldn't affect the other's.  I do agree, algae first, then high yield crops in aquaponics set up for tilapia and high yield crops with the recycled water supplying the hydroponic crops.  I didn't know wheat could grow hydroponicly. 
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/26/2016 02:15 PM
Also, things learned by growing food like this in confined spaces like on Mars could drastically increase yields and food production on earth.  Seem's like more research and effort by NASA in this area could get more money from congress to try these ideas out in say the high desert areas of southeastern Oregon, southwest Idaho, northern Nevada and northern Utah.  This is a high desert area, cold in winter, plenty of sunlight, very little water. 
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 02/26/2016 06:23 PM
Animals require twice as much algae to assimilate the same body weight than a more typical meal of cottonmeal, soybeans, corn or wheat.

So you either spend half your biomass on non-seed parts of the plant, or double the biomass to get the same mass of animal protein.

So the issue becomes: What's easier on Mars? Growing plants or growing algae.

Most people think it's plants, because you can "just put up a greenhouse". But as previously discussed, you probably can't. The complications on Mars make it easier to just use a hydroponic grow-room under artificial light.

A few say algae, because you can "just array pipes/tubes on the ground". But like the greenhouse, it will invariable be harder than that.

So what will be easier and use less energy?
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 02/26/2016 06:28 PM
I had the thought that the tubes used to grow the algae out on the Martian surface could theoretically also serve as the radiators for the base/city. Double duty. Use the waste heat from the base/city to warm the algae water, while still gaining the energy-saving benefits of using Martian sunlight for growth.

However, while there are likely lots of systems that could perform double duty in such a way, I am deeply suspicious of our ability to create self-regulating interdependent systems.

It's like using plants (or algae) to both grow food and recycle oxygen from CO2. The odds that you can perfectly balance the dietary needs with the oxygen needs of the base/city seems unlikely. Particularly when plants are generally more "fussy" than people about the quality of air.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 02/26/2016 07:55 PM
All these proposals and questions, should be addressed either in the Artics, or in the cold desert regions of earth.  Not only with agriculture, but with ISRU equipment to extract water from the air, especially in desert regions, make oxygen for humans, and even to make CH4.  Energy needs should be monitored for each and everything made or produced. 

Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/27/2016 08:02 PM
I doubt larger livestock would ever be used on Mars. It's debatable that larger livestock are practical on Earth with the amount of resources required to produce the useable calories.

Mars colonists will have to get use to fish, rabbits, and guinea pigs. Maybe chickens because they are small and produce eggs. Steak and bacon can be imported from Earth for special occasions.

I don't see grain production either, considering the amount of area that would take. Stick with algae production.

You are almost certainly mistaken because ... capitalism.

If there are colonists willing to pay for real meat (and there will be) then there will be people willing to rear it. And as rearing meat requires grass and grain that'll happen too.  Eventually.

Ditto bread.

As for chickens, have you any idea how many food products require eggs? My guess is that there will be poultry from very early days.
You can make eggs from algae. Yup. It's a thing:
http://vegnews.com/articles/page.do?pageId=7069&catId=8

Red meat especially will cost a ridiculous amount of money on Mars. Like, to maintain a grass-fed steer would cost about as much as maintaining half a dozen people in terms of space in terms of life support, habitable volume (an acre of pressurized, lit green space per steer), power, etc. Probably like $1000 per pound or something like that. A little better than shipping it frozen all the way from Earth, but not much.

Far more likely would be feeding algae to cattle. Still really, really expensive, maybe $100 per pound of meat. Maybe for Christmas or something.

People hugely underestimate exactly how expensive meat will be on Mars.
Title: Re: Scaling Agriculture on Mars
Post by: CuddlyRocket on 02/27/2016 09:12 PM
People hugely underestimate exactly how expensive meat will be on Mars.

That will make it desirable!
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 02/28/2016 12:04 AM
People hugely underestimate exactly how expensive meat will be on Mars.

That will make it desirable!
...and also irrelevant to "scaling agriculture."
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/28/2016 03:50 AM
When we are talking about animals, animals will eat the ENTIRETY of a plant. It is not like people where we will only eat part of the plant and throw away the rest: We harvest and dry the stem and feed it to the animals, we take the cottonseed after the fiber and the oil have been removed and feed the rest to the animals etc. When we are talking about animal feed we use the entirety of the plant (at least above ground), though we will need to change the ratio of how the plant is delivered in order to have a balanced feed. I am pretty sure that said vegan egg may be tasty, there is one problem though: what is the machinery and raw materials required to make that egg? Also eggs are so prevalent today because they are cheaply produced in factory farms, rather than necessary for life. Eggs do have the best protein available, but their use has more to do with their availability. I do see red meat on Mars, eventually, not early.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 02/28/2016 06:24 PM
When we are talking about animals, animals will eat the ENTIRETY of a plant. It is not like people where we will only eat part of the plant and throw away the rest:

Except your original comment compared rates of animal growth from algae feed with rates of growth from seed-meal feed, so that's what I responded to. If you want to use whole-of-plant feed, then you need to use that as the comparison. You can't pick one for one comparison, then pick another for a different part of the comparison.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 02/29/2016 03:34 AM
When we are talking about animals, animals will eat the ENTIRETY of a plant. It is not like people where we will only eat part of the plant and throw away the rest:

Except your original comment compared rates of animal growth from algae feed with rates of growth from seed-meal feed, so that's what I responded to. If you want to use whole-of-plant feed, then you need to use that as the comparison. You can't pick one for one comparison, then pick another for a different part of the comparison.

If you know of a paper where someone has compared growth rate of algae with a specific meal composed of an entire plant as tilapia feed, please share it on this thread. I am not associated with a research institution engaging on this kind of research. I did find the paper below which says that artificial feed in a tank leads to better feed conversion ratio than algae:

http://seagrant.uconn.edu/whatwedo/aquaculture/pdf/ncrac114_tilapia.pdf

The paper talks about keeping a proper pellet size, protein content and particle size (i.e. how much the feed is milled). In a nutshell the paper, which is a guide published by USDA, claims that artificial peletized feed from plants is better than their natural diet of algae. Knowing what I know about animal nutrition, I am not surprised. Bovines fed an artificial diet have higher efficiency than grazing animals
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 02/29/2016 06:29 AM
The paper talks about keeping a proper pellet size, protein content and particle size (i.e. how much the feed is milled). In a nutshell the paper, which is a guide published by USDA, claims that artificial peletized feed from plants is better than their natural diet of algae. Knowing what I know about animal nutrition, I am not surprised. Bovines fed an artificial diet have higher efficiency than grazing animals

Thanks. New information for me but I can't say I am much surprised. It means like for other uses the algae would be filtered out, depending on analysis maybe augmented with protein from bacteria and then pressed to pellets. A process similar to what would be done to feed chicken, rabbits or even larger animals. Though I think larger animals will be a long time coming, if ever.

Maybe early in development the inefficiency would just be accepted and Tilapia grow slower than possible. More efficient industrial production would come later.

Edit: fixed quote
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 03/01/2016 11:18 PM
When we are talking about animals, animals will eat the ENTIRETY of a plant. It is not like people where we will only eat part of the plant and throw away the rest: We harvest and dry the stem and feed it to the animals, we take the cottonseed after the fiber and the oil have been removed and feed the rest to the animals etc. When we are talking about animal feed we use the entirety of the plant (at least above ground), though we will need to change the ratio of how the plant is delivered in order to have a balanced feed. I am pretty sure that said vegan egg may be tasty, there is one problem though: what is the machinery and raw materials required to make that egg? Also eggs are so prevalent today because they are cheaply produced in factory farms, rather than necessary for life. Eggs do have the best protein available, but their use has more to do with their availability. I do see red meat on Mars, eventually, not early.

One useful animal may be a goat of all things as it can act as a recycler and produces a lot of useful things and doesn't need to space cows do.
Of course we can say there will never be cows as someone will probably figure out how to make it work.

Another option raise insects and then feed them to chickens along with algae pellets.
Yes there is loss in conversion but it's an acceptable one for what you get in return.

You don't want to be operating at max efficiency and carrying capacity of the habitat normally normally as if something goes wrong and you loose half your crop production there is no option of moving to a more efficient survival food source when you are already there.

Plus depending on just a few sources of food for most of your nutrition such as just algae and soybeans would be courting disaster.

Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 03/02/2016 01:13 AM
If you can grow lichen outside on Mars, then animals that can eat lichen all of a sudden sound like a good idea. But if you have to grow everything inside, then I'm sorry but the vegans are right.
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 03/02/2016 01:38 AM
Let's talk about growing stuff outside. What's possible, what can we imagine and what would make it more feasible?

Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 03/02/2016 01:41 AM
Let's talk about growing stuff outside. What's possible, what can we imagine and what would make it more feasible?
Nothing better to motivate thinking than the idea we might have to eat vegan! :D

(Not that I disagree... Cheese is a staple for me, and bacon is fantastic.)
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 03/02/2016 05:56 AM
Let's talk about growing stuff outside. What's possible, what can we imagine and what would make it more feasible?
Nothing better to motivate thinking than the idea we might have to eat vegan! :D

 ;D

I have this one crazy idea. Design a GM plant that grows its own pressure vessel, probably derived from a cactus. It would be drip fed through pipes. Probably even with CO2 as it would be hard to get CO2 in while keeping water from escaping. It would need a raised ambient temperature. That would be easy I imagine. Build a plastic cover that has a UV resistant coating on the outside and a infrared reflecting coating on the inside. A very efficient greenhouse with a plastic sheet just a few micrometer thick.

It sure would need major advances in understanding of genetics and genetic engineering. It may not be competetive with growing algae in pipes as that is about as efficient as it gets. Especially when algae are genetically modified to produce carbohydrates, fat and protein as needed which may be a lot easier than the outside plant.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 03/02/2016 01:19 PM
When we are talking about efficiency in an agricultural setting, it is very different than from an engineering setting. Efficiency means if we will need 100 or 400 m2 to grow enough calories in balanced nutritional form for one person. We do not face the kind of issues found is say electrical engineering where if you try to increase efficiency in an installation's electrical system the result could be creating instability or worse. To add another link in the food chain is to reduce efficiency, hence there is no reason to have a herbivore eat crickets. In any case goats are herbivores, just not very discriminating ones. Pigs are omnivores. If we could make goats ear crickets, it would still be reducing efficiency by 2 or whatever is the feed conversion ratio of crickets.

I've been trying to keep this discussion in the realm of science rather than science fiction. It might just be possible to create a Martian lichen/cactus type organism. Will it be grazeable by domesticated animals? Certainly they could not survive Martian conditions, so we would need to harvest and bring it inside. Would it even be edible, and if so what handing would it require?
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 03/03/2016 04:53 AM
If you can grow lichen outside on Mars

It'd grow slow as hell. It'd make mountain-top lichen look like a speed-demon.

I have this one crazy idea. Design a GM plant [...]

You're invoking "magic". Once you invoke that level of SF technology, you can wave your hand and make it do anything you want.

Real GM is incredibly limited. We cannot design plants that can do things that are beyond the capability of the contributing species, only move those capabilities between species (if we're lucky.)

Even just "design a plant that can tolerate a nearly pure CO2 atmosphere" is beyond us. (That would allow you to simply pressurise a greenhouse with raw Martian atmosphere.)
Title: Re: Scaling Agriculture on Mars
Post by: QuantumG on 03/03/2016 05:16 AM
I was more interested in questions like: if you were to spray the dirt on Mars with water would it freeze or sublime into a gas? Would that be instant? Does the time of day matter? Would the dirt absorb the water like a sponge or would a layer of ice form preventing further uptake? Could you fill a ditch with ice? Would the ice sublime into gas over time? If you covered it with a plastic sheet and sealed at the edges would liquid water form? Could you maintain an appropriate temperature and pressure under the sheet to grow something? Would this scale?

Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 03/03/2016 06:08 AM
I have this one crazy idea. Design a GM plant [...]

You're invoking "magic". Once you invoke that level of SF technology, you can wave your hand and make it do anything you want.

I agree, that is why I used "crazy". This said, GM is only at the beginning and there is no way of knowing what we can do in 50 or 100 years. That hypothetical plant is still a stretch.
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 03/03/2016 06:39 AM
I was more interested in questions like: if you were to spray the dirt on Mars with water would it freeze or sublime into a gas? Would that be instant? Does the time of day matter? Would the dirt absorb the water like a sponge or would a layer of ice form preventing further uptake? Could you fill a ditch with ice? Would the ice sublime into gas over time? If you covered it with a plastic sheet and sealed at the edges would liquid water form? Could you maintain an appropriate temperature and pressure under the sheet to grow something? Would this scale?

In that NASA workshop on landing sites it was said it needs at least a 1m regolith cover to stop sublimation. Any water sprayed on the surface will sublime though not extremely rapidly unless it is a very concentrated brine which plants don't like. You could make some hardy lichens grow under such conditions, it was tested. I doubt it would be worth it though.

Very low lying areas already have a pressure that sometimes allows liquid water, not brine. So greenhouses with extremely low pressure, just enough to keep water liquid would be possible. Building for that limited pressure would not require as much material spent as fully pressurized greenhouses.

A plastic sheet cover with UV protection outside and infrared reflection inside. Such a sheet is certainly doable. It should make a great greenhouse and with sufficient regolith mass to buffer over night temperatures can be stabilized. It is only an idea and needs verification. Wide swings of conditions and possibly overheating during warm periods in summer may be a problem.

I have read of some NASA research on plants under low pressure. At some point the plants behave strange. Something at low pressure indicates drought to them, even when steeped in water which limits pressure reduction. They were optimistic though that with research that problem could be overcome as it is "only" a mislead reaction by the plants not a basic limit. So yes, I believe it may be possible with a lot of research to have large greenhouses with a pressure as low as maybe 50 mbar may at some time in the future. But not under existing surface conditions. I prefer to think about greenhouses at 200 mbar/3 PSI. That pressure facilitates plant growth under the right atmospheric mixture and would allow people to work with only oxygen masks. These conditions would probably require relearning agriculture to achieve good yields though.

As a side thought. Any machinery that stays outside will experience wide day/night swings in temperature. Unpressurized sheds with such a cover will avoid the worst of it and make heavy equipment work better I believe.

Edit: corrected typo
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 03/03/2016 07:05 AM
I agree, that is why I used "crazy". This said, GM is only at the beginning and there is no way of knowing what we can do in 50 or 100 years.

Which is why it's pointless to discuss outside of a SF context.

I mean, if you've designed a plant that can survive in a near vacuum, why not go all the way and seed space. Asteroids, comets, icy moons; spores flung through space to seed new bodies. Even out to the Oort cloud, Dyson's comet trees.

Come to think of it, why not Niven's stage-trees? Engineer trees to grow a solid-rocket-motor core.

Or more practically, design your magic Mars cactus to grow with a pressurised, oxygenated hollow inside. Even better, colony plants. On Mars a pressurised volume can support a huge mass, or alternatively reach a huge size.

Oh, wait, same with the space plants, hollow pressurised volume, filled with a secondary ecosystem. Ecosystems, plural. Layers deep, each layer specialised in its niche, overall self-repairing and self-reproducing.

QuantumG,
Surely most of your questions can be answered just with a phase diagram for water? At Mars atmospheric pressure the water will boil until it loses enough heat to freeze. Then it'll continue to slowly sublime if the temp is above the sublimation point. If you trap it in a tube, obviously you can pressurise it (and indeed as it boils off it'll pressurise itself) until it freezes without subliming. But if you try to merely cover it with a sheet, the pressure will lift it away unless you anchor the sides with tons on ballast per square metre.

I doubt you can trap enough heat to keep water liquid, except for brief periods on summer days. The surface area available for cooling is too great, given the convective effect of even Mars' thin atmosphere (a vacuum would be easier.) It's one of the reasons I'm deeply skeptical of the value of a Martian greenhouse. By the time you add all the things you need to make it viable, you might as well switch to a fully enclosed artificial grow-room.
Title: Re: Scaling Agriculture on Mars
Post by: Patchouli on 03/03/2016 05:16 PM
If you can grow lichen outside on Mars, then animals that can eat lichen all of a sudden sound like a good idea. But if you have to grow everything inside, then I'm sorry but the vegans are right.

Not necessarily true as you can raise fish inside tanks.
https://www.youtube.com/watch?v=6XHd9kMZzPQ

You probably could raise a lot of tilapia,shrimp and craw fish inside a converted MCT tank.
https://www.youtube.com/watch?v=lhPfKK6smLA
So you better learn to like sea food.

Though once you have a few  thousand people or so you can seriously considering building large structures on Mars which will open up more opportunities.
This is why I feel early colonists need to be the types of people who work on arctic bases and oil drilling sites.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 03/05/2016 05:28 PM
So, captain, we need transparent aluminum to contain the pressure. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 03/11/2016 02:34 AM
In a greenhouse on earth the losses from the skin of the greenhouse due to convention are insignificant compared to the losses due to IR radiation from the plants inside the greenhouse. PET is actually transparent to IR, only glass and PVC reflect back IR at the skin. Thermal blankets around greenhouses are actually IR reflecting material to help keep energy in. On Mars losses due to convection at the skin will probably be even more insignificant.

The world famous agricultural university of Wagenigen made an experiment growing crops on simulated Mars soil:

http://www.spacedaily.com/reports/First_tomatoes_peas_harvested_from_mock_Martian_farm_999.html
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 03/11/2016 04:30 AM
PET is actually transparent to IR, only glass and PVC reflect back IR at the skin.

Yes, that is why I suggest to coat a plastic sheet with some IR reflecting surface. That surface could be glass. I have mentioned before that plastic beer bottles have a very thin coating of glass, so the technology is available and cheap. In the case of the beer bottles the reason is to make the PET bottle unpermeable to oxygen which spoils the taste of beer while soft drinks are less affected. For a greenhouse it is the greenhouse effect. That's why I believe keeping greenhouses warm is not too hard.
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 03/11/2016 11:11 AM
[blocking IR] That's why I believe keeping greenhouses warm is not too hard.

It's not radiation that's the killer for a Mars greenhouse, it's the conduction and convection. The atmosphere of Mars can draw heat away from the surface of the greenhouse; and convection means that the thermal sink is constantly renewed, even on windless days.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 03/11/2016 02:27 PM
PET is not a good covering material for greenhouses in general. Even the best quality hard PET has a 10 year life cycle due to yellowing caused by UV radiation and I am talking about Earth with its ozone layer. You can imagine how long it will live on Mars. The trick on Earth greenhouses is to allow dew to condense on the interior surface of the PET film, water being of course reflective to IR. Problem is that high humidity is great for fungal diseases, we don't want that. The main reason PET is the most popular material is cost, most farmers try to minimize capital expenditure by using a wooden frame with PET cover, even though this means that it 10-15 years you will need to get rid of the entire structure since PET will be yellow and the (manufactured) wood will have been eaten by its enemies. I see clear PVC as the cover material on Mars, rather than PET

A greenhouse on Earth has 4 times the heating requirements of a house of the same size. Yes, the cold skin will be a permanent heat sink, but it is rarely on Earth the main cause of thermal loss
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 03/15/2016 01:47 AM
Another news article on Mars crops, this time on potatoes:

http://www.theguardian.com/global-development/2016/mar/14/spuds-in-space-growing-potatoes-on-mars-climate-change-the-martian-ridley-scott
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 03/15/2016 08:18 AM
PET is not a good covering material for greenhouses in general. Even the best quality hard PET has a 10 year life cycle due to yellowing caused by UV radiation and I am talking about Earth with its ozone layer. You can imagine how long it will live on Mars. The trick on Earth greenhouses is to allow dew to condense on the interior surface of the PET film, water being of course reflective to IR. Problem is that high humidity is great for fungal diseases, we don't want that. The main reason PET is the most popular material is cost, most farmers try to minimize capital expenditure by using a wooden frame with PET cover, even though this means that it 10-15 years you will need to get rid of the entire structure since PET will be yellow and the (manufactured) wood will have been eaten by its enemies. I see clear PVC as the cover material on Mars, rather than PET

A greenhouse on Earth has 4 times the heating requirements of a house of the same size. Yes, the cold skin will be a permanent heat sink, but it is rarely on Earth the main cause of thermal loss

Agree with almost everything written here.  Transparent plastics on Mars need to be made from highly UV resistant polymers with good chemical stability in a reducing environment.  UV damage isn't just about yellowing, either - the glazing becomes brittle.  And you don't want brittle glazing on a pressure vessel!  The only thing I'd change is that fluoropolymers like PTFE are the most likely candidates    And you generally have additives and coatings for a variety of purposes.  PVC is more durable than PET in greenhouse environments but it's still nothing like PTFE.  PVC thin-film glazings generally last 2-3 years instead of ~1 year like PE and PET, while I've never seen it as rigid panels; rigid panels are usually either acrylic or, more commonly, polycarbonate, layered into corrugated sandwiches.  The only reason fluoropolymers are seldom used on Earth in greenhouses is the cost; there's no question that they'd provide the greatest UV and chemical resistance. 

The only real question is scratching - I honestly have no clue how physical abrasion from Mars dust would take its toll over time.  Individual dust grains on Mars are tiny buy can have quite significant velocity.  On Earth scratching is generally only an issue from macroscopic objects.

All of that said, the solar constant on Mars is so low to begin with (never mind before dust gets involved) that you're going to need supplemental light either way.  Plants consume *vast* amounts of energy to grow, far more than most people envision (I grow food crops under artificial light myself) - and the waste heat can be significant. 

Maybe one could use a relatively small amount of glazing combined with reflectors to bring light in without panel / conversion / LED losses...
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 03/15/2016 12:23 PM
Maybe one could use a relatively small amount of glazing combined with reflectors to bring light in without panel / conversion / LED losses...

Concentrating reflectors don't deal well with indirect light, so they'll need to track the sun. That requires more mass than just throwing rolls of thin-film solar out. (Reflectors will also be worthless during dust storms.)

Don't get me wrong, plants consume *vast* amounts of energy to grow, far more than most people envision (I grow food crops under artificial light myself) - and the waste heat can be significant.

Waste heat is significant for incandescents/halogens, but LEDs are much less wasteful at the point of emission (the LED itself.)
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 03/15/2016 12:48 PM
Quote
Concentrating reflectors don't deal well with indirect light, so they'll need to track the sun. That requires more mass than just throwing rolls thin-film solar out.

Quite true (although I'm sure any mission planner would balk at a plan that involves just "throwing rolls thin-film solar out"   ;)  I think you'd find them buried very rapidly if they're not elevated and at an angle). 

Major dust storms are problematic in general.  You don't bring the sort of battery masses that can store the kind of power levels  needed to grow plants for weeks on end, that would be just far too much mass.  Mars really isn't an ideal environment for plants... but you deal with what you've got.  Either way, if you can consistently generate vast amounts of power, you can grow plants under lights.  It's as simple as that... so long as one doesn't underestimate the huge level of power consumption that it takes.  Or underestimate the technical challenges.  Such as how plants really don't like airtight spaces... for example they give off gases like ethylene that are more toxic to them than CO is to us (yep, I've lost plants to ethylene before).  Or how there are so many unexpected details that can kill your plants, like the effects of leaving a door open or closed to your grow room (yep, that got me too).  Or how hard it is to measure exact levels of minor nutrients, and how so many deficiencies look the same (same).  Or how many treatments to diseases also have the potential to kill your plants instead (way too often).  And on and on.  And each plant species has its own quirks and needs.  Growing in enclosed spaces on limited nutrient media is tricky.  But the difficulties  can be overcome with sufficient preparation, and there's a lot of work going into it.

Quote
Waste heat is significant for incandescents/halogens, but LEDs are much less wasteful at the point of emission (the LED itself.)

I grow under both LEDs and fluorescent, mainly LED.  Trust me, while the LEDs kick out a lot less heat per unit light, they still kick out a lot of heat at the light intensity levels that caloric crops need to grow.  I have to vent the heat out of there.

The biggest, heaviest part of an LED grow setup by far is the heat sink.  On an industrial scale on Mars you'd probably want liquid cooling.
Title: Re: Scaling Agriculture on Mars
Post by: JasonAW3 on 03/15/2016 02:03 PM
Quote
Waste heat is significant for incandescents/halogens, but LEDs are much less wasteful at the point of emission (the LED itself.)

I grow under both LEDs and fluorescent, mainly LED.  Trust me, while the LEDs kick out a lot less heat per unit light, they still kick out a lot of heat at the light intensity levels that caloric crops need to grow.  I have to vent the heat out of there.

The biggest, heaviest part of an LED grow setup by far is the heat sink.  On an industrial scale on Mars you'd probably want liquid cooling.

     I'm not really sure that this is as much of a problem as you may suppose.

     In fact, the waste heat could prove a useful supplementary heating source for the main habitat systems for any crew or colonists attached to the agricultural growing systems.

     This could be accomplished through the use of heat pump distribution systems as well as air re-circulation systems.

     While the growing area would be kept at a higher than average CO2 level than the rest of the habitable sections of the colony/base, a nanoporous air filter membrane, designed to pass O2 and prevent CO2 from passing out of the growing area, could like wise, add redundancy to the primary Life Support Systems, reducing the wear and tear on that system as well.
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 03/15/2016 06:23 PM
Oh no, I absolutely wasn't meaning to imply that the waste heat is a bad thing.  I was pointing out that your lights are themselves heaters - even LEDs   :)  I basically heat part of my house with the output from my lights.

Being realistic, for early missions, we probably won't see any greenhouse at all.  We'll probably see some pre-prepared "Mars plant growth experiment" with a silly acronym that basically amounts to a small pre-prepared hydroponics/light box that you just plug in and it germinates a handful of plants that provide irrelevant caloric input, but which NASA makes a big deal out of in press releases.

Later missions would still only produce a small fraction of calories, but at least take it more seriously - either large stacks of hydroponic-fed light trays in a big modular assembly, or an inflatable, low-pressure greenhouse (the latter gives you more space at less mass penalty, but it means that work in there needs to be conducted in a pressure suit, which would be pretty awkward)

Seriously actually feeding people on Mars with local plants, I think that's a pretty long way off...  just from consideration of how much mass you have to send in order to do so.

I think another way to put it is: note how people on ISS aren't growing their own food.  ;)  Yeah, their being in LEO makes it easier to deliver food, but it also makes it easier to deliver a greenhouse!  ;)
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 03/15/2016 11:30 PM
Microalgae can easily, efficiently, and compactly provide the majority of calories. Lettuce and other hydroponic plants can spruce things up.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/06/2016 03:21 AM
This article showed up on facebook

http://astrogeo.oxfordjournals.org/content/57/2/2.18.full.pdf?keytype=ref&ijkey=NWL0rzGK5CzJJOM
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/06/2016 01:41 PM
Ethylene is not toxic to plants, it is a maturity hormone. It is a chemical signal to move on to the next phase of their life cycle, hence the ethylene ovens that are used to mature oranges picked early (still green) and the ethylene piped in the holds of reefer ships carrying bananas so that they arrive to the final customers soft and not with the consistency of wood. If we get year long planetary dust storms, as has happened in the past, we will have a problem. Yes, sending a greenhouse on Mars requires significant weight, but so is sending anything. ISRU based on local materials is still quite off; I find IonMars' concept of building using local stones and an earth based resin intriguing but I also remember comments that this is likely not function and that the walls may leak excessively. Metal based and inflatable habitats require more infrastructure before they become ISRU. I see no reason why out of a 5 building habitat one of these buildings is not the plant growth chamber, irrespective of its form.

There is no human culture which bases its nutrition exclusively or primarily on algae. As far as I know the most mature project to identify the plants necessary for space settlement is ESA's MELiSSA. While spirulina is an important part of the identified kit, they do not have as their primary nutrition source. Before we judge efficiency let's have the experiments necessary. Electrical cars are very green, until you realize that the power charging them came out of a coal fired power plant. We need experiment with three or four greenhouses on Earth, one exclusively with algae, one with hydroponic plants, one with soil based on Mars stimulant, like the Wageningen experiment published last month and a control. Let's run them all side by side and see what actual efficiency in terms of energy, fertilizer, radiation, calories etc actually looks like. Then with real data we can discuss what is best. Main road block here: funding. Considering how expensive space science can be this sort of experiment can be quite cheap, but it has never been a priority of funding agencies, either of space or of agronomy.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/06/2016 02:17 PM
A lot of food here on earth is grown in hydroponic greenhouses.  Tomatoes for one.  A lot of prepper/survivalists people use aquaponics, growing tilapia in tanks and using the waste water off the bottom of the tanks to supply water and nutriants to plants in a greenhouse.  Some claim to grow enough food for their families in their back yards.  Of course atmosphere isn't a problem here.  I don't think it would take a lot of money or effort to experiment with growing food in Martian conditions.  Either Antarctica or a high cold desert region in the US since Mars colony will probably be near the equator and get 12 hours daylight and 12 hours night approximately similar to earth.  Antarctica will have longer summer days and longer nights in winter.  We do however need to experiment on earth.  Who knows, new ways to feed more people with less space can benefit humanity, not just to feed a Martian colony. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/06/2016 06:05 PM
This comes from another thread, but apparently there is a limit of 50 g/day of Single Cell Protein for fast growing farm animals https://en.wikipedia.org/wiki/Single-cell_protein

If we have a chicken that grows to 5 kgs in 50 days and has an FCR of 1, then it will need 50 grs of SCP, such as algae, per day. Since it is unlikely to have an FCR of less than 2, this means 100 grs of SCP, which is toxic. People also are known to get gout at over 100 g/day of SCP.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/06/2016 07:00 PM
Yes, a varied diet is best.  Algae, tilapia, all kinds of vegetables, then maybe chicken.  Grains could be a problem early on, but a lot could be shipped from earth.  However, I did read about 1/2 acre of wheat can feed a family of 4 for a year in bread.  It would be labor intensive in small units, whereas on earth thousands of acres are planted in the US and harvested mechanically. 
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/06/2016 07:03 PM
500 m2 per person? Sounds right but you cannot just live on bread, and not only in the way Jesus said it. Wheat on its own is not capable of providing a balanced diet.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/07/2016 04:19 PM
Yep, I know you can't just eat wheat alone, or bread alone.  Rice is actually more nourishing, again it takes space and labor.  Vegetables are fairly easy and take up little space.  Grains may grow easy enough, but take up more space and will be more labor intensive.  From what I understand, they grow leaf lettuce on the space station now, for fresh salads. 

Based on the length of this thread, NASA or some space agency needs to do a lot more space related food growth to determine all the variables that have to be addressed.  Algae? hydroponics or soil based or both? tilapia? frogs for frog legs?  Insects? What vegetables and how many or how much room required?  Will Mars need 4 times the space per person for food production, 10 time, or only two times?  How much living space also?,  How much is needed for power production?  Methane production?, oxygen production, argon production, lox production, water production, water treatment methods?  Lots and lots of questions, lots of research needed for Mars to become independent of earth as early as possible. 
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 04/07/2016 04:40 PM
Microalgae in tanks. Just saying.

If you want, you can even feed it to tilapia.
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 04/09/2016 06:12 PM
Ethylene is not toxic to plants, it is a maturity hormone.

Trust me, ethylene absolutely is toxic to plants (as well as being a maturity hormone); I've lost tomato plants to ethylene toxicity before after sealing up a greenhouse too tightly.

http://content.ces.ncsu.edu/ethylene-sources-symptoms-and-prevention-for-greenhouse-crops

Note that the toxicity levels begin at the fraction-of-a-ppm (aka ppb) levels.  *Extremely* low levels.  To plants, ethylene is the "death hormone".  It signals for things to break down.  Normally it's not a problem, even in a greenhouse, because air leaks cycle fresh air in and dirty air out.  But when a greenhouse gets sealed up too tightly, ethylene accumulates.  Ethylene can also be a problem from outgassing of plastics, combustion products, decay of dead plant matter, etc.  I had to implement a countercurrent heat exchanger to fix the problem, to get the air cycling again without losing heat.

Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/09/2016 10:22 PM
I remember a NASAstudy on plant growth under low pressure. That study included comparison on how plants do with or without removal of ethylene. Ethylene did reduce plant growth. I don't know if this qualifies as toxic but it poses a disadvantage.

I am presently not at home and cannot refer to that study.
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 04/11/2016 03:17 AM
Could catalytic oxidation work to prevent ethylene buildup in a greenhouse?  More broadly, could any number of unwelcome vapors be broken down by such a method?
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 04/11/2016 03:54 AM
Could catalytic oxidation work to prevent ethylene buildup in a greenhouse?  More broadly, could any number of unwelcome vapors be broken down by such a method?
Ethylene makes a fantastic rocket propellant, better than methane, and can be made into plastics easily. Maybe we harvest it? :D
Title: Re: Scaling Agriculture on Mars
Post by: The Amazing Catstronaut on 04/11/2016 08:11 AM
Ethylene makes a fantastic rocket propellant, better than methane, and can be made into plastics easily. Maybe we harvest it? :D

That's an exceptionally good idea - plastics manufacturing on mars would be perfect if you want to ISRU entire habitable volume. Manufacture concrete out of regolith and then seal up/coat/decorate with plastic - hey presto, you have a living space.
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 04/11/2016 10:04 AM
Could catalytic oxidation work to prevent ethylene buildup in a greenhouse?  More broadly, could any number of unwelcome vapors be broken down by such a method?
Ethylene makes a fantastic rocket propellant, better than methane, and can be made into plastics easily. Maybe we harvest it? :D

Given that it's in parts-per-billion quantities, no  ;)

That said, yes, like everything else you can either filter or catalytically decompose it; it's a question of how effective you make your filtration system and how frequently you cycle all of the air through it.  It just means more mass and power consumption.  A potential issue for catalytic decomposition: I'm not sure how effectively it would work at reduced pressures, and most of the work today is on reduced pressure greenhouses.  It might be worth looking into.

Air filtration is a big, important issue to get right for Mars in general (aka, for people as well as plants).  Beyond outgassing and other contaminants.  The more we learn about Martian dust, the nastier of a substance it turns out to be and the lower our tolerance for even small amounts getting into the habitat.  You don't want to be breathing perchlorates, arsenic and hexavalent chromium mixed with silica grains ideally sized for silicosis.  You don't even want to touch the stuff; Martian dust is believed to be corrosive enough to organics that it would burn skin like handling lye.  Mars is a reducing environment, not an oxidizing one.  The surface chemistry is very different from Earth.

(Every so often you hear about some "researchers grew plants in amended Martian soil" story.  Always check the details - it's almost always JSC MARS-1, which is ground Hawaiian rock.  It roughly matches the elemental composition and particle size, but is not reducing.  You probably could turn Martian regolith to something like JSC MARS-1 by a high temperature roast in the presence of oxygen, but that's experimentation for the future)
Title: Re: Scaling Agriculture on Mars
Post by: Robotbeat on 04/12/2016 01:59 AM
I agree it wouldn't be worth extracting (that's why the smiley). But my other statements stand. :) Propylene is slightly better, and often ethylene and propylene are co-produced from syngas (which is likely a far better way of producing plastics).
Title: Re: Scaling Agriculture on Mars
Post by: Hanelyp on 04/12/2016 04:48 AM
Air filtration is a big, important issue to get right for Mars in general (aka, for people as well as plants).  Beyond outgassing and other contaminants.  The more we learn about Martian dust, the nastier of a substance it turns out to be and the lower our tolerance for even small amounts getting into the habitat.  You don't want to be breathing perchlorates, arsenic and hexavalent chromium mixed with silica grains ideally sized for silicosis.  You don't even want to touch the stuff; Martian dust is believed to be corrosive enough to organics that it would burn skin like handling lye.  Mars is a reducing environment, not an oxidizing one.  The surface chemistry is very different from Earth.
What happens to those nasties once you introduce a warm human friendly atmosphere with O2 and water?  A good dust cleaning system in airlocks still seems a good idea.
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 04/12/2016 11:38 AM
Quote
What happens to those nasties once you introduce a warm human friendly atmosphere with O2 and water?

If you're thinking that they disappear immediately, the answer is no.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/12/2016 05:37 PM
In biology there is a definition of toxic, and ethylene in plants does not meet it: sure, it causes it's eventual death which is why fruit (that produces a lot of ethylene) is kept as separate from other biological materials (e.g. potato tubers) as possible. Fruit refrigerators require special fans that replace the air with new air instead of just keeping it and cooling. However ethylene is not considered toxic like say cyanide which gunks up the metabolic pathway, in both plants and animals. Indeed for plant ethylene we are talking about the ppm range, but the usual way we get rid of ethylene's effect is better aeration (basically, dilution). How would that would work on Mars, I have no idea, but ethylene is not a typical problem in greenhouses, no matter how closed they are. It is nothing compared to say moisture. Ethylene is a problem in refrigerators and other storage facilities.

My understanding is that Martian dust is in the PM2.5 and PM10 range. The usual solution on earth is to limit cars/industrial activities that produce these materials and to hope for rain to wash it off the air. No idea how to do it on Mars.

I agree that there is little to discuss anymore on the subject and it would be great to move to experiments. Alas I am not on a funding committee or anything. I will keep posting to this thread new new articles posted on the subject, unless we really want this thread to die
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 04/12/2016 08:01 PM
Quote
In biology there is a definition of toxic, and ethylene in plants does not meet it: sure, it causes it's eventual death which is why fruit (that produces a lot of ethylene) is kept as separate from other biological materials (e.g. potato tubers) as possible. Fruit refrigerators require special fans that replace the air with new air instead of just keeping it and cooling. However ethylene is not considered toxic like say cyanide which gunks up the metabolic pathway, in both plants and animals. Indeed for plant ethylene we are talking about the ppm range, but the usual way we get rid of ethylene's effect is better aeration (basically, dilution).

:(  So many things wrong with this.

1. That's not what toxic means.

https://en.wikipedia.org/wiki/Toxicity
https://en.wikipedia.org/wiki/Toxin
http://www.atsdr.cdc.gov/
http://www.atsdr.cdc.gov/toxicsubstances.html
http://www.medicinenet.com/script/main/art.asp?articlekey=34093

Toxic means that it can harm life.  That's it.  It's not more specific than that.  It doesn't have to be deadly - although ethylene is.

2. Parts per billion, not parts per million.  Visible damage begins at as low as 10 parts per billion - that is  incredibly toxic.  For example, carbon monoxide toxicity begins at about 35 ppm (3500 times higher) for long-term exposure (OSHA allows up to 50ppm over an 8-hour work shift).  The OSHA PEL for hydrogen cyanide is 10ppm over an 8-hour work shift.  Yes, ethylene is three orders of magnitude more toxic to plants than hydrogen cyanide is to humans.

3. Ethylene doesn't just cause "eventual death" - ppb levels will only kill through accumulated long-term damage, but  but ppm levels kill them pretty quickly ("quick" from a botanical perspective... everything happens slowly with plants).  One technique to identify manufactured gas leaks is to look for dead plants:

http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=1460&Type=2

Under 24 hours causes severe epinasty in tomatoes - here's visual evidence after 24 hours treatment:

http://endowment.org/wp-content/uploads/2014/07/tomatoepinasty1.jpg

It can kill tomato plants within days if levels are high enough.

The reason ethylene causes ripening is because it causes cell death.  In most situations, it is the death hormone in plants - it triggers apoptosis:

http://link.springer.com/chapter/10.1007%2F978-94-011-4453-7_38#page-1

It's also the hormone that causes leaves to die and shed, causes flowers to fall off, causes stems to stop growing, etc.  It's the counter to auxin, the growth stimulation hormone.

(The exception is in the soil, where it things are reversed - it increases root formation, causes seed germination, etc)

Quote
How would that would work on Mars, I have no idea, but ethylene is not a typical problem in greenhouses, no matter how closed they are

You're arguing with someone who grows a veritable jungle of rare plants and has built greenhouses.  Yes, ethylene absolutely can and does cause problems in greenhouses on Earth when air circulation is closed off too tightly and/or artificial or dense natural sources are present.

Quote
It is nothing compared to say moisture

This has to be a joke.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/13/2016 12:54 AM
I also have had greenhouse experience, growing tomatoes in Portugal and somehow ethylene in this context never came up, just as it never came up as a undergrad in the appropriate classes. So, I looked up Dr. Google; could it be that I have such a large lacuna in my education? No, not quite. The issue indeed exists, for cut flowers and potted plants:

http://www.hort.cornell.edu/mattson/leatherwood/
http://www.oardc.ohio-state.edu/joneslab/images/ethylene_extension.pdf

As you can see these are extension literature, "grey" but extremely important. The most complete list I found was in this one:

http://content.ces.ncsu.edu/ethylene-sources-symptoms-and-prevention-for-greenhouse-crops

It contains mostly ornamentals but also five horticultural plants (with reported concentration of some effect): cucumber (0.1 ppm), eggplant (0.8 ppm), lettuce (0.05 ppm), pepper (0.5 ppm), sweet pea (not reported) and tomato (0.05 ppm). On the other hand ornamentals were pages upon pages. What is consistent is that the comments are that damage is cause not by the innate production of the plant but rather from an external source at the greenhouse, such as cigarette smoke and badly working heater.

In the greenhouse I was working in Portugal there was no heater. In the Oeste region the temperature rarely drops below freezing. The problem was that with closed windows at night humidity was permanently high leading to one disease after another. It got so bad they ended their (experimental) runs at the end of June, instead of going all the way to fall and take advantage of higher producer prices. Ethylene was never an issue. Nor was it even brought up when I was an undergrad in Greece, ethylene was only discussed in terms of refrigerators.

You are working with tropical plant greenhouses, that was a hint to me: The tropics generally are hot and humid, unlike the hot and dry Mediterranean. Tropical plants are better adapted to high humidity, though my understanding is that they still suffer from fungi. Also I do not remember you mentioning any horticultural plants. Simply put there is not universal greenhouse experience, I remember reading how greenhouses in Martinique and tropical regions in general serve as umbrellas rather than blankets. Your experience with exotic plant greenhouses is not necessarily universal.
Title: Re: Scaling Agriculture on Mars
Post by: Rei on 04/13/2016 03:02 AM
I also have had greenhouse experience, growing tomatoes in Portugal

Warm-weather greenhouses and cold-weather greenhouses are entirely different beasts.  Cold-weather greenhouses deal with sealing up as much of the greenhouse as possible, and also are more likely to be externally contaminated with ethylene (such as by a leak in a heater system).

Quote
The issue indeed exists, for cut flowers and potted plants:

Why are you acting as if I haven't already given references?

Quote
As you can see these are extension literature, "grey" but extremely important. The most complete list I found was in this one:

http://content.ces.ncsu.edu/ethylene-sources-symptoms-and-prevention-for-greenhouse-crops

It contains mostly ornamentals but also five horticultural plants (with reported concentration of some effect): cucumber (0.1 ppm), eggplant (0.8 ppm), lettuce (0.05 ppm), pepper (0.5 ppm), sweet pea (not reported) and tomato (0.05 ppm). On the other hand ornamentals were pages upon pages.

Cucumber, pepper, and tomato being some of the most important greenhouse crops grown on Earth.

The reason for the "pages upon pages" of ornamentals is twofold.

One, with ornamentals, appearance is everything.  With a food crop, if it takes on damage and reduced yield, it's a negative.  But with an ornamental, if it takes on damage, it's worthless.

Two is entirely unrelated to growing the crops - it's that ethylene causes flowers to age after being cut, so reducing ethylene damage is important in increasing their shelf life.

Quote
What is consistent is that the comments are that damage is cause not by the innate production of the plant but rather from an external source at the greenhouse, such as cigarette smoke and badly working heater.

The most common source of ethylene damage in greenhouses is defective heaters.  But it absolutely does happen in the absence of gas heaters when greenhouses are sealed too tightly, as plants themselves outgas ethylene.  Decaying plant matter is a particularly significant source.

Or, if you don't trust the experience of someone who has lost plants from ethylene buildup after an overly aggressive sealing effort:

http://ohiofloriculture.osu.edu/sites/ohioflori/files/d6/files/file/energy-conversion.pdf

Quote
An improperly functioning greenhouse
heating unit is the most common source of ethylene contamination.

Others sources of ethylene include:

Exhaust from combustion engines
Cigarette smoke
Leaky gas lines or contaminated fuel
Ripening fruits
Senescing flowers
Dying and decaying plant material
Wounded plant tissues

Note that all of the last four are plant sources.  In my case, I wasn't particularly diligent about hauling dead plant matter out to the compost heap.

It's simply a fact that plants outgas ethylene, and if there is little ventilation, it builds up to hazardous levels.  On Mars there is zero natural ventilation - only what you provide.

Quote
In the greenhouse I was working in Portugal there was no heater. In the Oeste region the temperature rarely drops below freezing.

Yes, and you're talking with someone who used to grow plants in Iowa and now grows in Reykjavík.  You're used to warm weather, ample leakage growing. 

Quote
It got so bad they ended their (experimental) runs at the end of June

Funny that you couldn't manage to do what pretty much every other greenhouse grower on the planet manages.  Humidity is more often a benefit in the greenhouse environment, as it suppresses some pest populations like spider mites.  What diseases were you having problems with?

And really, your windows were closed at night in June?  Does it really get that cold at night in June in Portugal?

Quote
Nor was it even brought up when I was an undergrad in Greece, ethylene was only discussed in terms of refrigerators.

I'll refrain from commenting on the quality of your education there.  :Þ

Quote
You are working with tropical plant greenhouses, that was a hint to me: The tropics generally are hot and humid, unlike the hot and dry Mediterranean. Tropical plants are better adapted to high humidity, though my understanding is that they still suffer from fungi.

The only fungal disease I've ever had problem with is rot in poorly situated bananas.  My biggest problem long term has always been spider mites - with periodic random problems in-between when I changed conditions (the aforementioned ethylene problem, excessive heat, excessive cold, phytotoxicity, etc... each one only bites you once, but it hurts when it does).  Some plants, I have to spray the leaves weekly or more if I don't wan't them mite infested (cocona, for example).  Whenever I get lazy, things are fine for several weeks, then all of the sudden I notice that the plants are dying and covered in webbing  :Þ  I could get longer-term protection, but I don't want to use anything more toxic like organophosphates (I use neem + sucrashield).
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/13/2016 04:22 AM
I've been looking my archives, and while I was not able to find a list of the diseases they had during that campaign, I did find a list of the substances used:

Table 48. Plant protection products used in the greenhouse

Product Active substance Containers Unit cost Total cost
Rufast Avance acrinatrina          1           11.44 € 11.44 €
Ortiva              azoxistrobina     1           47.98 € 47.98 €
Turex           Bacillus thurigensis 8            4.43 € 35.44 €
Ret-Bt          Bacillus thurigensis 2          17.45 € 34.90 €
Applaud       buprofezina            4            3.65 € 14.60 €
Thiovit          enxofre (wetable)  4            0.61 € 2.44 €
Aliete               fosetil-aluminum 1            6.91 € 6.91 €
Rovral              iprodiona            4            8.11 € 32.44 €
Plenum 25 WP pimetrozina        3            7.84 € 23.52 €
Scala                pirimetanil          1            8.94 € 8.94 €

The name of the active substance is in Portuguese. I was an Erasmus student and arrived on July 5th 2003. That year was exceptionally hot and dry, hence the multiple huge fires. However even in August, which was a record breaking August, I never felt the sort of heat I feel in Athens, it was rather comfortable and I was living at that point in Lisbon at Entrecampos, not in the countryside without the heat island effect. Even when the night temperature dropped at 20 C you still needed a jacket for the humidity which was bone chilling. In Lisbon there are entire neighborhood where they don't have central heating, even in brand new houses. I was not surprised that there was no heating in greenhouses, the surprising part was that we were talking about a high end hydroponic greenhouse. It was not however a commercial greenhouse, it was a demonstration greenhouse run by the local second level coop in cooperation with Instituto Superior d'Agronomia and with European funding. The idea was to see if the particular varieties grown could indeed grow under local conditions (think photoperiodism) and to demonstrate automations to farmers, including automated mechanized window opening and closing. Compared to the greenhouse we were taken at Ierapetra or Falassarna (both of these places are in Crete) and in Cyprus they were less advanced technologically. As Erasmus student I also took a few course at ISA and I was surprised that the agronomist degree was relatively easier and less intensive than in Greece. They only needed around 80-90 courses in 5 years to get their degree, as opposed to the 110 courses in 5 years that we needed at the Agricultural University of Athens

The humidity issue did come up not only in classes but also in discussions with farmers during field trips. It was an issue in the summer due to cooling panels, that wonderful invention that reduces noontime temperature from 40 C to 26 C by taking advantage that relative humidity is only 25%: you run water through a high porosity special material on one wall and pull air using fans you pull in outside air through that panel, leading to 26 C air at 100 % RH. No heat stroke for the plants but they get vulnerable to molds and rots. This is why you usually grow the plants in the off season on a Mediterranean greenhouse, when all you need is heating and no cooling and producer prices are higher.

We are indeed at the point where we need some sort of actual experiment if ethylene will be an issue on Mars. Let's not forget the first rule of plant protection: we intervene only if the intervention makes economic sense, if the income from production saved is more than the cost of the intervention. If we still get our tomatoes in the quantities we need but deformed, that is not an issue on Mars. We are looking for edible tomatoes, not good looking tomatoes. In any case greenhouses crops last most often 7-9 months in Greece. When the summer heat starts most farmers just cut off irrigation, harvest the last crop, cut off the plants and often solarize the ground and then move on to growing a far more lucrative crop: North European tourists.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/13/2016 12:54 PM
Another new article about a CU student growing strawberries for Mars:

http://www.denverpost.com/business/ci_29756500/growing-strawberries-space-isnt-far-from-reality-says

From the article:
Quote
Plus, she added: "Turns out plants are really hard to grow. They don't just take care of themselves. A lot of people think you just add water and nutrients. If only it were that simple. Engineers are very good at killing plants."
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/15/2016 02:18 PM
Great thread.  Mind if I cross-thread a bit, to pull your thoughts over to our side?  We're looking at a specific challenge.

So, if you had:

- a Mars greenhouse structure, radiation-protected, admitting 60% incident light and having all required supplemental electric light, heat and water,

- enclosing 2,000,000 m3 of pressurized space, enabling

- 70 acres of growth

and you had:

- 20 years to prepare, so that cutting-edge tech could be plausibly perfected,

how might you load an MCT (i.e., 100 tons +/-) to stage the initial "biome"?



Goal: self-sufficiency for 350, any surplus being high-value bonus.



This "biome MCT" would be one of the eight MCTs required to complete the core colonial facilities proposed in our Lake Matthew scheme.  I'd be delighted if the clever contributors to this thread would take a shot or two at this aspect of the challenge.



Relevant posts:

Self-sufficiency and Local Provisioning (http://forum.nasaspaceflight.com/index.php?topic=40019.msg1516848#msg1516848)

8 MCTs (http://forum.nasaspaceflight.com/index.php?topic=40019.msg1518549#msg1518549)



Thanks.

(http://thumbs.dreamstime.com/t/colorful-vegetables-colander-isolated-over-white-34209518.jpg)
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/15/2016 02:44 PM
Ok, so we have to find a cold dry, maybe high altitude area to test a sealed greenhouse for Martian conditions.  North Chile desert maybe, at high altitude.  Thin air, little to no water, cold like Mars.  It must be done somewhere if we are going to colonize Mars. 

First, every eatable plant known should be grown to test everything and test productivity. 
Second, algae should be grown and processed into food pellets, and or grown with tilapia. 

Once plants are figured out, the introduce chickens, and maybe small animals.  They can eat parts of plants that humans do not eat, or waste from tilapia not reused in fertilizer could be processed to feed the chickens protein supplements as chickens can eat bugs, worms and such. 

Equipment for air circulation can have attachments to separate out gases, or other contaminents. 

Like I said, it must be done somewhere to simulate Martian conditions.  Artic areas might be another if a colony is built near a Martian glacier.  Anyone got any suggestions as to where this should be tried?
Title: Re: Scaling Agriculture on Mars
Post by: Paul451 on 04/15/2016 03:26 PM
Ok, so we have to find a cold dry, maybe high altitude area to test a sealed greenhouse for Martian conditions.

There is nowhere on Earth that even crudely approximates Mars. Not even close. Not even "but it's good enough for a first run", nor "but it'll give us a basic idea". Nothing you learned from a greenhouse build on the Atacama plateau would tell you anything about building a greenhouse on Mars.

You are making the classic mistake that Mars is "like a cold, dry, high altitude desert, but a bit more".

Mars is a near vacuum. You cannot build a "greenhouse" on the ground because it cannot sustain the pressure (it will push up from the ground as soon as you pressurise it. You need ten tonnes of ballast for every square metre of surface area.) That means you're building an entirely enclosed pressure vessel, very heavy, no soil.

You cannot pressurise the external atmosphere without extreme equipment. Mars is a good quality vacuum, trying to concentrate the Martian atmosphere is the difference between pumping out a good vacuum, and pumping out an extremely hard vacuum. Your starting point with Mars is the point where most industrial processes stop trying, because the cost escalates quickly and you need specialist lab equipment that only works on a small scale.

The top of Mt Everest is an English summer garden by comparison.

It must be done somewhere if we are going to colonize Mars.

The only place to simulate a Martian "greenhouse" is in a completely artificial environment. And you can house that completely artificial environment anyway.

It'll be a hell of a project though. Good quality vacuum chamber, big enough to build a large structure inside, with enough distance between the test structure and the vacuum chamber walls to avoid complication from thermal radiation and circulation entrapment (of the remaining trace gas). Because you must cool the chamber continually to model the thermal conduction and radiation of the test structure and the convection of the trace gases.

And you have to do it safely enough that you aren't risking killing either your engineers or your test-crew.

(Thankfully, Mars is only a good vacuum. So the vacuum chamber itself only requires regular industrial vacuum systems. The thermal stuff will require customised systems though.)

Interestingly, it's vastly easier to test a deeply buried, artificially lit grow-room. You just need an airtight chamber and limited imports of resources; a limited power supply; and an outside wall temperature kept at the average annual temperature for the presumed site of a base on Mars. (At a certain depth, the ground temperature matches the average annual surface temperature above that spot. It's kind of neat.) Other than that, you can site it anywhere.

But if you a testing a "greenhouse" (something that uses natural light), you must test the thermal and near-vacuum effects. Otherwise, it's meaningless.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/15/2016 04:03 PM
The most comprehensive current program to build a space colonization kit is ESA's MELiSSA. The MELiSSA project has gone as far as identifying 8 or so crops necessary to build a self sufficient and nutritionally balanced meal regiment. Now when MIT shot down the MarsOne concept they also used several other models of colony growth crop selections but MELiSSA has actually tried to use crops that can be grown as part of ECLSS.

350 people is a huge population. At this level the issue is not so much the short term technical matters of having functional food growth facilities. We are also taking about having large scale resource utilization and cycling. Rather than a greenhouse in Acatama or Antartica, try studying similar sized remote and not so communities: Where they get fertilizer, what high level inputs are necessary (e.g. pesticides), human resources etc. There is good reason why food is shipped to hostile and remote location like polar Canada and Antarctica instead of creating a system to grow locally. Studies ought to be in more temperate regions such as Europe

70 acres is a little over 28 hectares, which at 350 people means a little over 800 m2 per person. Hydroponics is able to grow sufficient food at this area per person. However when we are talking about a 350 person colony we would most likely also need a animal growth facility, which will process some of the byproducts of the plants. If we assume that at the peak of labor it will require 1 40/hr person per 500 m2, we will need during peak harvest 560 people! Of course, the 40 hr week is legal convention, but it is certain than during parts of the year we will require the entire colony harvesting. Hydroponics is high labor!

More ideas will follow later, but I found this interesting economic analysis from Texas A&M, which is where labor requirements were inspired

http://aggie-horticulture.tamu.edu/greenhouse/hydroponics/economics.html
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/15/2016 07:32 PM
The dirty secret about agriculture is that in reality it has never been self sustaining. Even in its more traditional form agriculture requires input, albeit from the environment rather than people. If we want a colony of 370 people, we need to find a location with the mineral resources required. CO2 comes from the atmosphere, H20 from the soil, we can created N fertilizer artificially from the atmosphere but P and K we need to find the proper rocks. 28 hectares is a gigantic area, we will need tons on P and K rocks, irrespective of the crop grown. According to Dr Google the largest greenhouse in the world is the Eden project in England, according to wikipedia the two biomes cover a bit over two hectares. 28 hectares is the area under cover you will find in entire counties, for example at Lassithi perfecture there were 843 ha of greenhouses in 1995/6. When we are talking about a facility that big this requires separate plant nurseries, seed production under protected conditions (from different diseases) and all sorts of infrastructure. This kind of area will also produce prodigious amounts of plant remains, it is better if we utilize them as feed. We will be producing a large quantity of compost anyway, so it is best if we differentiate and not have just hydroponics. There will be too much compost not to use as a soil amendment, plus we can better recycle the nutrients. Still we will need hydroponics for their intensity. It is very hard for me to calculate the labor demands, but it is certain that intensive horticulture is labor intensive.

If we go directly from nothing to growing that big an area under cover, you are courting disaster. As earlier discussion point out, the Icelandic greenhouse experience is quite different from the Mediterranean experience. We will need to get experience from 1,000 m2 greenhouses before we get to the 28 ha. We do not have experience with growing food for production purposes at an environment as closed as the one on Mars. Let's start small before we get big
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/15/2016 09:35 PM
Quote from: AegeanBlue
...P and K we need to find the proper rocks. 28 hectares is a gigantic area, we will need tons on P and K rocks

Thanks for this thought, and many thoughts.

In this scheme, energy production and storage are scaled to provide up to 10 MW, day or night, much of that power devoted to energy-intensive processing of regolith, brine and atmospheric gas, in early days.  ECLSS reprocessing of waste is also supported.  And so for simplicity, I'd like to assume that sufficient P, K, Fe, Mg, Ca and N are being extracted and cycled locally to enrich the 70 acres, if that's not too far-fetched for an exercise.

Quote from: AegeanBlue
We will need to get experience from 1,000 m2 greenhouses before we get to the 28 ha. We do not have experience with growing food for production purposes at an environment as closed as the one on Mars. Let's start small before we get big

Absolutely.  Every small-scale greenhouse experiment seems to turn up a new wrinkle in the lettuce leaf.  This "Biome MCT" challenge is intended only as a creative exercise, and best guess.  No warranty implied.
Title: Re: Scaling Agriculture on Mars
Post by: spacenut on 04/15/2016 10:12 PM
What about plant rotation.  You wouldn't harvest all at one time.  Plant a little each day, harvest a little each day, to spread out the work load over time.  You can do this in a controlled environment.  On earth we have seasons outside, but in a sealed greenhouse controlled environment, rotation is the only way, so it won't take 500 people to harvest for 350 people. 

I've told the story of a farm family who has a 1,000' greenhouse (about 300 meters).  The have pallets of plants on a giant slow moving conveyor belt.  They put on a pallet of planted seeds on one end each morning, and take off full grown vegetables at the other end.  The greenhouse has lighting for night growing.  This greenhouse and associated equipment take up about 10 acres.  They harvest the same amount of vegetables that the once did on about 240 acres once a year.  They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc. 
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/16/2016 03:17 AM
What about plant rotation.  You wouldn't harvest all at one time.  Plant a little each day, harvest a little each day, to spread out the work load over time.  You can do this in a controlled environment.  On earth we have seasons outside, but in a sealed greenhouse controlled environment, rotation is the only way, so it won't take 500 people to harvest for 350 people. 

I've told the story of a farm family who has a 1,000' greenhouse (about 300 meters).  The have pallets of plants on a giant slow moving conveyor belt.  They put on a pallet of planted seeds on one end each morning, and take off full grown vegetables at the other end.  The greenhouse has lighting for night growing.  This greenhouse and associated equipment take up about 10 acres.  They harvest the same amount of vegetables that the once did on about 240 acres once a year.  They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc.

That's a tremendous efficiency, and the story seems quite relevant.  Thank you.  Is there a video or paper on the methods?

Btw, I posted a video of an experimental greenhouse in Japan, where "plant rotation" is really "plant rotation".  Post:  Self-Sufficiency and Local Provisioning (http://forum.nasaspaceflight.com/index.php?topic=40019.msg1516848#msg1516848).  Is there much similarity with your story, or do the methods seem very different?

Our proposed greenhouse would have the general form seen in this image of hab dome geometry.  It differs in that annular garden plots would be located on the terraced floor below, and "hanging garden" plots (perhaps rectilinear) would be added above.  It's not too hard to imagine spiral rotator automation on some annular plots, and linear conveyor automation on some rectilinear plots.  If necessary and feasible.

(http://www.lakematthew.com/wp-content/uploads/2016/03/hab_rough_geometry_1400_450-768x247.png)

habitat rough geometry, as enabled by Lake Matthew micro-environment, 300m scale

Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 04/16/2016 08:16 AM
I wouldn't get too carried away mechanizing the plant beds, just more materials to take to Mars and more things to go wrong.

70 acres for 350 people is very generous, but perhaps you're working on less than optimal growing conditions, that is, it may be better to use larger areas rather than expect to easily have, for example, the perfect blend of nutrients. Where do you plan to get the nutrients from, not imported from Earth I assume? Certainly getting the N, P, K, S etc out of the Martian atmosphere and soil, with its toxic characteristic, wouldn't be easy.
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/16/2016 06:01 PM
Quote from: Alf Fass
Where do you plan to get the nutrients from, not imported from Earth I assume? Certainly getting the N, P, K, S etc out of the Martian atmosphere and soil, with its toxic characteristic, wouldn't be easy.

ECLSS recovery would supplement, but looking at the regolith: 

Regolith would be toxic to some extent, and when soaked it would make a potentially toxic brine.  The Water Treatment, Brine and Electrolysis MCT would need to recover fertilizing salts from the brine, which acts as the "waste stream" input for a "zero liquid discharge" (ZLD) system.  ZLD systems clean waste streams from oil fields, landfills, mines, etc., producing a series of fertilizing salts as output.  Regolith brine is unpleasant, but it would be just another waste stream for treatment, from the ZLD perspective. 



ZLD brochure (https://www.gewater.com/kcpguest/documents/Capabilities%20Brochures_Cust/Americas/English/GEA17904_Zero_Liquid_Discharge_Brochure.pdf)

ZLD animation (https://www.youtube.com/watch?v=EH1kSg7x0d0)



Quote from: Burke
We manufacture them, by the way.

Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/17/2016 05:39 AM
They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc.

Per previous posts, let's assume that both fertilizer and cleaned sand are provisioned locally, in adequate quantity.

Questions:

- What would you need to ship in the Biome MCT, to complete an optimal cubic foot of topsoil?  (.028 m3)

- And can you estimate the cargo mass required for that cubic foot?

- Stretch goal: Can you sketch a process to complete that cubic foot of topsoil in situ, using even less cargo mass?

(http://images.costco-static.ca/image/media/150-316300-894__1.jpg)

Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 04/17/2016 10:36 AM
They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc.

Per previous posts, let's assume that both fertilizer and cleaned sand are provisioned locally, in adequate quantity.

Questions:

- What would you need to ship in the Biome MCT, to complete an optimal cubic foot of topsoil?  (.028 m3)

- And can you estimate the cargo mass required for that cubic foot?

- Stretch goal: Can you sketch a process to complete that cubic foot of topsoil in situ, using even less cargo mass?

(http://images.costco-static.ca/image/media/150-316300-894__1.jpg)



Initially I was puzzled by your question, having been involved with agriculture I'd always assumed that the requirements for plant growth were appropriate amounts of: light, nutrients, water and heat, I'll even throw in gravity, initial plant life, an atmosphere and space since, you know, Mars ain't Earth.

But after further investigation I now realize you're talking about something entirely different to those mundane physical necessities for plant growth, you're asking about Essence Of Life, which is basically what plants have instead of souls.

Through extensive research I can advice that you'll need 42 LUE's (Life, the Universe and Everything) of Essence Of Life, which, inconveniently, can't actually be measured in the physical terms known to Man.
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/17/2016 02:17 PM
They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc.

Per previous posts, let's assume that both fertilizer and cleaned sand are provisioned locally, in adequate quantity.

Questions:

- What would you need to ship in the Biome MCT, to complete an optimal cubic foot of topsoil?  (.028 m3)

- And can you estimate the cargo mass required for that cubic foot?

- Stretch goal: Can you sketch a process to complete that cubic foot of topsoil in situ, using even less cargo mass?

(http://images.costco-static.ca/image/media/150-316300-894__1.jpg)



Initially I was puzzled by your question, having been involved with agriculture I'd always assumed that the requirements for plant growth were appropriate amounts of: light, nutrients, water and heat, I'll even throw in gravity, initial plant life, an atmosphere and space since, you know, Mars ain't Earth.

But after further investigation I now realize you're talking about something entirely different to those mundane physical necessities for plant growth, you're asking about Essence Of Life, which is basically what plants have instead of souls.

Through extensive research I can advice that you'll need 42 LUE's (Life, the Universe and Everything) of Essence Of Life, which, inconveniently, can't actually be measured in the physical terms known to Man.

Thank you, Alf. Always taking it to the next level.



Guckyfan, you're a +1'er, I see.  And big on algae (http://forum.nasaspaceflight.com/index.php?topic=35877.msg1273888#msg1273888), upthread.  If I might ask, how might algae be used to best effect, in the staging of the Lake Matthew greenhouse (http://forum.nasaspaceflight.com/index.php?topic=40019.msg1516848#msg1516848) biome?
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/17/2016 10:20 PM
Guckyfan[/b], you're a +1'er, I see. 
I like just emphasizing what posts I agree with. :)


And big on algae (http://forum.nasaspaceflight.com/index.php?topic=35877.msg1273888#msg1273888), upthread.  If I might ask, how might algae be used to best effect, in the staging of the Lake Matthew greenhouse (http://forum.nasaspaceflight.com/index.php?topic=40019.msg1516848#msg1516848) biome?

Producing algae is very different and would not fit into this greenhouse as I understand it. They can be grown in a very basic and cheap structure. That's their main advantage over using greenhouses. I saw a setup where algae were grown in pipes at the Uni where my daughter studied. Pipes mean you don't need any pressurized structures around them. Pipes can be produced and deployed cheaply on a large surface taking in a lot of natural sun light. Any pressurized large structures are expensive.
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/18/2016 12:20 AM
Guckyfan[/b], you're a +1'er, I see. 
I like just emphasizing what posts I agree with. :)

And I see what you agree with.   



Constructing an optimal cubic foot of topsoil, with the givens, and using the minimum practical cargo mass -- it's obviously a challenge.  What must be added to the sand and fertilizing salts, and how? 

- Silt-sized particles?  How much, and sourced from where?

- Micronutrients?  How much, and which ones are actually critical to crops of interest?

- Which organisms would be most beneficial?  Fungi, nematodes, other?  Could a specific set of beneficial and hardy organisms be tailored to primitive soil?  And how quickly could their mass be doubled?

- Is a composting cycle needed at the start, and if so, how much compost is really needed, and what might be the best way to kickstart the cycle?

- What is the hardiest useful cover crop?

And so forth.  This thread has touched on many aspects of the topic, "scaling agriculture on Mars".  Optimization of soil is an important aspect.  It could make the difference between misery and luxury, as others have noted in one way or another.

So here's a concrete problem:  making the optimal cubic foot of topsoil, with minimum cargo mass. 

How to solve the problem, or try to solve it, leveraging the exploratory discussion that's gone before, and participants' hard-won experience?
Title: Re: Scaling Agriculture on Mars
Post by: Vultur on 04/18/2016 02:07 AM
So, if you had:

- a Mars greenhouse structure, radiation-protected, admitting 60% incident light and having all required supplemental electric light, heat and water,

- enclosing 2,000,000 m3 of pressurized space, enabling

- 70 acres of growth

and you had:

- 20 years to prepare, so that cutting-edge tech could be plausibly perfected,

how might you load an MCT (i.e., 100 tons +/-) to stage the initial "biome"?

Well, seeds (and seed potatoes etc. -- potatoes are extremely efficient in terms of calories per acre. So they should be one of the staple crops.) don't weigh very much. Most of the mass is going to be going into soil.

And 70 acres of soil is going to be a LOT of mass, so you're going to need to convert Martian dirt into usable soil. So if water ISRU is already provided for, most of the mass is probably going to need to be soil amendments. Bacteria and nematodes to inoculate the soil, a starter amount of organic material to get the whole thing going, pH amendments etc.

This would need some looking into. I've seen a lot of claims about Mars perchlorate dust being ultra-toxic, but this seems questionable, since there are naturally perchlorate-bearing soils on Earth and perchlorate-rich Chilean nitrates were used as fertilizer for ages.

Per previous posts, let's assume that both fertilizer and cleaned sand are provisioned locally, in adequate quantity.

Questions:

- What would you need to ship in the Biome MCT, to complete an optimal cubic foot of topsoil?  (.028 m3)

Well, one would need to find out whether the perchlorates in Martian soil are genuinely a problem in this context, and if so, how to deal with that.

Beyond that, when you say fertilizer is assumed, are you thinking of just N/P/K? If so, you'd need micronutrients.

There's also soil biota -  microbes, symbiotic mycorrhizal fungi, beneficial nematodes etc. If you're going to grow legumes, their symbiotic nitrogen-fixing bacteria should be provided.

Also, depending on what pH and soil texture you get from the Martian raw materials, these may need to be amended.

Quote
- And can you estimate the cargo mass required for that cubic foot?

- Stretch goal: Can you sketch a process to complete that cubic foot of topsoil in situ, using even less cargo mass?

Well, micronutrients are needed in relatively small quantities and soil organisms will multiply. 

But it will be very dependent on what amendments are needed in terms of toxicity (if any), pH, soil texture etc. You may want to take soil texture into account when choosing crops.

Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/18/2016 02:53 AM
Quote from: Vultur
...one would need to find out whether the perchlorates in Martian soil are genuinely a problem in this context, and if so, how to deal with that.

They'd be removed by ZLD (http://forum.nasaspaceflight.com/index.php?topic=35877.msg1519701#msg1519701) within the Water Treatment, Brine and Electrolysis MCT.  Probably an electrodialysis stack would be inserted into the ZLD chain for this purpose.

Quote from: Vultur
...when you say fertilizer is assumed, are you thinking of just N/P/K? If so, you'd need micronutrients.

There's also soil biota -  microbes, symbiotic mycorrhizal fungi, beneficial nematodes etc. If you're going to grow legumes, their symbiotic nitrogen-fixing bacteria should be provided.

Yes, was wondering which micronutrients are really needed in this context.  Likewise, organisms.  (Legumes + N-fixing bacteria, good example.)  Please see previous (http://forum.nasaspaceflight.com/index.php?topic=35877.msg1520168#msg1520168).

Quote from: Vultur
Also, depending on what pH and soil texture you get from the Martian raw materials, these may need to be amended.

pH is certainly a great unknown.  Can pH of the primitive soil be balanced with local product?  E.g., with a cover crop? 

Organic matter can balance pH, and obviously a cover crop is a quick source of organic matter.  Rye can grow in pH ranging from 4.5 to 8.0, supposedly.  If so, a first cover crop of rye could provide the organic matter needed to balance pH.

A pallet of rye seed, whereby the MCT armada of neutralizing agents (such as limestone and elemental sulfur) may be left back on Earth.

?
Title: Re: Scaling Agriculture on Mars
Post by: guckyfan on 04/18/2016 03:21 AM
pH is certainly a great unknown.

To us maybe. NASA has tons of data from at least Curiosity, likely Spirit and Opportunity too.
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/18/2016 03:43 AM
pH is certainly a great unknown.

To us maybe. NASA has tons of data from at least Curiosity, likely Spirit and Opportunity too.

This is primitive soil pH, as a ZLD product.  Not the raw regolith itself.
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 04/18/2016 03:50 AM
Plants don't need any organic matter in soil, you'll need it only if you're growing fungi.

Micro-nutrients are called micro-nutrients because there's not much of them, a few grams or kilograms per hectare will do you.

Bacteria are required for good soil health, mainly to breakdown organic matter and make nutrients available in a form plants can use, that is in a water soluble form. The handy thing about bacteria is that in terms of multiplying they leave rabbits for dead.

See that water soluble bit? the brine on Mars is going to have all the nutrients you'll need, it'll just be a matter of separating them and getting the concentrations right.

PH, most plants prefer a PH around 6 - 6.5 mainly because at that PH you get less metals toxicity and the best balance in nutrient solubility , on Earth we use lime to reduce the acidity of soils, a couple of tonnes a hectare will increase the PH of most soils by 0.2 or more, given that you've already got an industry in place to extract those soluble nutrients I'd expect there'd be some process available to increase the levels of base ions, things as basic (pun!) as slag from iron smelting has been used to increase PH.
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 04/18/2016 04:01 AM
Quote
However, in August, 2008, the Phoenix Lander conducted simple chemistry experiments, mixing water from Earth with Martian soil in an attempt to test its pH, and discovered traces of the salt perchlorate, while also confirming many scientists' theories that the Martian surface was considerably basic, measuring at 8.3.

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

Reducing the PH will be even easier, it'll happen naturally with the removal of perchlorates and the addition of the soluble nutrients.
Title: Re: Scaling Agriculture on Mars
Post by: Vultur on 04/18/2016 04:59 PM
Plants don't need any organic matter in soil, you'll need it only if you're growing fungi.

Is it absolutely needed? No, you can grow plants without any soil at all (hydroponics/aeroponics). But it can certainly help - in terms of amending the soil texture, IIRC, as well as nutrients (which can certainly be provided in other ways).

Also, many plants (including many crops) benefit from mycorrhizal symbiosis with fungi in the soil biota.
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 04/18/2016 07:03 PM
It wouldn't be worth carting soil organic matter to Mars when it's not needed, as long as nutrients are provided with water soluble artificial fertilizers mycorrhiza aren't required.

If I were growing plants on Mars I'd go straight to hydroponics and skip the hassles of using soil.
Title: Re: Scaling Agriculture on Mars
Post by: AegeanBlue on 04/18/2016 07:24 PM
To continue from my previous contribution, there are several optimization selections in a greenhouse in terms of labor and efficiency. Harvesting algae is just a matter of draining the water, you then simply move the biomass for processing. When we are talking about tomatoes, in addition to the hand harvested tomatoes that come out of a greenhouse, there are also the industrial tomatoes which usually go toward canning. To pick greenhouse tomatoes you need a worker who once or twice a week goes through every plant and visually inspects them and selects the fruit that is at the proper level of ripeness and put them in his cart. For industrial tomatoes what you need is an automated harvester, a machine the size of a tractor. When the farmer judges that the majority of the fruit is in proper ripeness the just drives the harvester through the tomato lines and collects all. Between the two options you get on optimization problem: Do you want to minimize labor at the cost of having half the yield or do you want to minimize the size of the agricultural habitat at the cost of increased labor?

Having exactly one agricultural greenhouse of that size is in my opinion a major mistake. It is not so much an issue of safety (you get a disaster, you lose everything) but also an issue of forcing all plants to have the same climate. A classical example from arborology class is the apple and orange tree problem. In Greece we grow both, in higher altitude and latitude regions apples and in lower latitude and altitude regions oranges. There are parts of Greece (e.g. Corinthia) where both trees are grown in nearby plots. Colder years are optimal for apple trees and not so great for orange trees, warmer years we have the opposite. Much as it will cost you more cover material, it is better to have more than one habitat, each optimized for a range of species rather than one size fits all. This also extends to lighting. I am aware of greenhouses where they plant the rows at different times so that they can harvest at different times. I don't think that we will need something that drastic.

In terms of pH it depends on the species with the typical range between 6 and 8. There is a fallacy that soil is necessary for agriculture, it is not if you use hydroponics. With hydroponics keeping the pH is just an issue of maintaining the solution pH, there will be interactions with the substrate at first, which is why it is better in case where we do not know the reactivity of the substrate to irrigate at the start without the plants present, but eventually the substrate will adopt the pH of the medium. For hydroponics what matters most is mechanical composition, i.e. silt sand and clay. There is no optimum mechanical composition for all plants, each one has its own requirements. Rice for example requires a high silt soil that drains poorly. Most other cereals though prefer well draining soils. This is also true for actual soils.

Soil organic matter is the source of micronutrients. The only micronutrient that you will need is large quantities is Iron, I doubt you will have a shortage of that in the red planet. Organic forms of the micronutrients are more plant available, but for the most part issues with micronutrient deficiencies have more to do with competitions due to pH than actual deficiencies in the soil. Keeping the pH within bounds, a serious problem when talking about field soils, should keep any deficiency from arising. My understanding is that Martian soils are acidic. This is usually solved by adding lime or other sources of Ca. In Greece a popular source of Ca is marble dust, which after all is a byproduct of the construction industry. However even in wet Western Greece keeping the pH within bounds is an issue of using the right fertilizer. Greece is simply not that wet to require the sort of industrial use of lime necessary in the US East Coast or Brazil. I am a friend of microirrigation wish is a very efficient use of water as opposed to flood irrigation. Industrial liming is not necessary when talking about microirrigation, and not just for hydroponics.

Even if we do go the soil way (as opposed to hydroponics) we do not need to carry any organic material separately to Mars. We can create soil compost out of the waste treatment system. We just co-compost the biosolids of the waste treatment system (a.k.a. activated sludge) with proper material such as wood or plant stems. We just mix the ensuing compost with Mars' red soil we will see the creation of soil. We do not need deep soils for agriculture, in the Mediterranean out of necessity we farm with cms of soil, that is all that is left after several millenia of farming, hence the relative popularity of hydroponics. There is a strong possibility that we will need to carry some soil species from Earth because the human colonists will not carry it in their digestive tract for us, e.g. some nematodes. In that case one bag of biological material ought to be enough. We cannot know in advance though what is necessary and carry it in our kit. I would rather carry a kit of hydroponic substrate (e.g. rockwool) than spores of soil. In any case there is a strong possibility that once we reach Mars we can use the insulation of the spacecraft as hydroponic substrate.

With that much land per colonist we can move from growing just food to growing other stuff. Agriculture can provide food, fiber, biofuels and bioplastics. Fiber on earth usually means wood fiber but in our case it would mean something like cotton and flax. Cotton provides an edible oil (#2 in the world in production among edible oils after soybean oil) and the seed after the gin and oil extraction is edible by animals. But do we want to have a clothing industry on Mars or would we rather bring all our clothing from Earth? Biofuels are pretty unnecessary on Mars, I see no reason why to have biodiesel or bioethanol engines on Mars, as opposed to electric engines. Let's not forget that on Mars we will need to bring the oxygen along with the fuel. Bioplastics are pretty important, considering how ubiquitous plastic is in space technology. We will need though to also bring an entire infrastructure to Mars.

I will keep on intervening whenever my works allows me time
Title: Re: Scaling Agriculture on Mars
Post by: Alf Fass on 04/18/2016 09:12 PM
AegeanBlue mentions the advantage of multiple green houses, I agree.

The layout I'd go for is  several tunnel houses leading off a central processing spine, to get 4 ha of hydroponics greenhouse floor (which is all you'd need to provide food for 350 people) one approach would be with (as an example) 6 meter wide tunnel houses, the total length would be 40,000 m^2 / 6 = 6,700 m, if each house was 250 meters long thats 26 houses. If the spine ran east west with the tunnel houses coming off it north and south, spaced 30 meters apart the complex would cover an area of 20 ha (400 m x 500 m).

Despite Wstewart's skepticism, because of the heat and radiation insulation it provides I'll stick with covering the tunnel houses with regolith and using reflectors and light tubes to get natural illumination into them rather than using a transparent film, which would have to be robust (and therefore heavy) to let in light and retain the internal pressure but provide poor insulation.

The hydroponic green houses would provide a surplus of organic matter unsuitable for human consumption, this could be used to feed herbivores so there could soon be meat and eggs in the diet, a feedstock for organic chemicals, and compost to build soil for beds for plants less suited to hydroponics.
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/19/2016 03:20 AM
In terms of pH it depends on the species with the typical range between 6 and 8. There is a fallacy that soil is necessary for agriculture, it is not if you use hydroponics. With hydroponics keeping the pH is just an issue of maintaining the solution pH, there will be interactions with the substrate at first, which is why it is better in case where we do not know the reactivity of the substrate to irrigate at the start without the plants present, but eventually the substrate will adopt the pH of the medium.

re: pH

Hydroponics can be fine, yes, especially if soil is hard to come by.  However in this scheme we would begin with ZLD cleaned sand and fertilizing salts, just as byproducts of regolith/brine processing.  These byproducts might serve toward creation of an optimal soil, if cargo mass isn't prohibitive.  That's why I was leaning toward soil production, instead of hydroponics.

pH balancing might be harder in this new soil than in a hydroponic solution.  How to balance pH in the soil, without hauling many tons of neutralizing agent by MCT?  Working the thoughts forward:

- Does it make sense to use a fast-growing cover crop such a rye, to make a neutralizing organic matter?  Rye's hardiness in soil that's nutrient-poor, cold and far-from-neutral would seem to make it a good candidate for first crop under uncertain conditions.

- Should ZLD fertilizer salts be post-processed into different fertilizers, to increase their ability to alter pH?  I hesitate to raise that option, just because the addition of post-processing to the ZLD system would likely divert much of the MCT's power, mass and volume away from its core production (treated water and electrolysis gases).

- Can urea ammonium nitrate fine-tune the soil pH?  It could be sourced readily from ECLSS, precluding modification of the ZLD system.  Urea lowers pH while ammonium nitrate raises pH.  Therefore adjustment of the urea / ammonium nitrate ratio would seem a relatively easy way to fine-tune soil pH.  (Effectiveness?)

So at the moment I wonder if a cover crop + urea ammonium nitrate might perform the necessary pH balancing act.  I'm following up on that line of thought because if some such scheme were practical, it would reduce the Biome MCT cargo mass required for pH management - from tens or hundreds of tons, to some mere hundreds of kg.

For hydroponics what matters most is mechanical composition, i.e. silt sand and clay. There is no optimum mechanical composition for all plants, each one has its own requirements. Rice for example requires a high silt soil that drains poorly. Most other cereals though prefer well draining soils. This is also true for actual soils.

re: soil texture

Hmm.  It might be fortuitous that cereals prefer well draining soils.  I'm not sure how silt-sized and clay-sized silicate particles would be sourced in bulk, at a sandy bedrock site. 
Title: Re: Scaling Agriculture on Mars
Post by: LMT on 04/19/2016 03:25 AM
Having exactly one agricultural greenhouse of that size is in my opinion a major mistake...  Colder years are optimal for apple trees and not so great for orange trees...

The proposed adjoining habitat is of the same size, also 2,000,000 m3.  Naturally it would be coole