Farmers In The Sky

Frankly, I’m glad to have robots do it, as long as I get to eat the results. Though it might be relaxing to be able to spend time in the greenhouse and gardens.

[Update a few minutes later]

It’s Legos™. In space.

Meh. I was always a Tinker Toy™, Lincoln Logs™ and Erector Set™ guy myself.

30 thoughts on “Farmers In The Sky”

  1. “As long as Bruce Dern isn’t in charge.”

    I cried so hard at the end of that movie. Poor little robot with his little water can (T_T) Lost in space for all of time.

  2. Buried greenhouses on the moon with piped in sunlight – how is the heat being removed? Regolith is a very good insulator. Greenhouses in space are more about cooling than sunlight (room temperature radiators are limited to around 500W/m^2).

    My preference would be inflated tubular greenhouses in space. Say 200kg of polycarbonate film for a 10m by 2m diameter tube – enough to support a couple of people. The greenhouses also serving directly as radiators – use them for habitat cooling.

    Some plants can handle the radiation, but developing magnetic radiation shielding and greater biological radiation resistance is probably a good idea. In space greenhouses can be far more productive as they have full time access to sun and sun levels can easily be actively controlled.

    Presumably greenhouse tubes could be spun for gravity (spoke fashion) and they could be individually moved into shielded areas when direct human contact was desired. Use multiple redundant small farm tubes to help sustain micro meteorites.

  3. This reminds me of a question I wanted to ask about a recent edutainment program on Space. I don’t think it was Nova, but the organizers had a fair amount of NASA access and spokespeople walking though a variety of “So… what do we need for Mars, exactly?” type questions.

    The particularly troublesome element was on “Space Food.” I can completely understand the ‘just add water’ thinking for near space. But this entire section of the show revolved around NASA developing techniques to make 6+ year shelf-stable foods. Discussing how “We’re not quite there yet!” with freeze-dried pre-prepared chicken Kiev, or Mongolian beef stir-fry.

    Hello? Wheat and rice are mighty stable with just minimal drying. From practically pre-historical multi-year sieges no less. With freeze drying into a hermetically sealed package, I believe they pass well-into “Twinkie-land.”

    But the discussion didn’t revolve around how to (or how to train a robot to) turn easily preserved food into a reasonably varied diet. Nothing about growing fungi, hydroponics, or anything onboard in the slightest.

    They were seriously discussing ad nauseum the difficulties involved in designing, freezing, lifting, transporting and then actually eating food prepared in toto for the entire “6+ years” of the trip. With the focus being on how we (NASA) desperately needed more funding to “maintain nutritional value and taste” in food that has to sit on the shelf for six years.
    No wonder they can’t come up with a feasible weight budget.
    NASA can’t possibly fade into the NTSB-of-space fast enough to suit me anymore.

  4. how is the heat being removed?

    Probably the same way they get rid of the extreme heat required to bake oxygen out of the rocks. Temperature control and heat management are fundamental to everything. If we can’t figure that out there’s no hope for us.

    the show revolved around NASA developing techniques to make 6+ year shelf-stable foods.

    True idiocy. This is why you need people living there, to overrule the idiots.

    We may have to export live soil if they don’t start working on how to make soil from local resources. Hydroponics are somewhat limited, but pot growers have been doing most of the ‘field’ research. Ahh, space cowboys…

  5. Ahh, space cowboys…


    I made a large purchase from Pleasant Hill Grain last year. They claim that their food can be stable for 20 years if stored in cool temperatures.

    Maybe Mars colonizers need to be trained in cooking from scratch instead of heating freeze-dried meals.

  6. I’m wondering about acerage here. It would make more sense to have a huge inflatable unroll – something with some surface area. That looks like it might be able to grow enough food in a year to feed one person – for a month

  7. – I expect that a suitable mix of microbes introduced to moistened pulverized granite or similar will produce good soil if you wait long enough. May take a few years.

    – Rice and wheat keep well if dry and cool. But I’ve heard some vitamins, such as C, have long term stability problems in storage.

  8. What wait for space? If someone has a robot gardener that can pick the d*** tomato worms off the plants (ugh) I’d like to know about it right now.

  9. Ummm… I’m missing something here. This is proposed for the moon, at least in part… and works by capturing sunlight and piling it in via fibre optics, but there doesn’t seem to be any mention of a little tiny problem; day length! That won’t work overly well in the dark, IMHO.

    The lunar day just over 14 days… and so is lunar night. Did they just forget that? There’s mention of putting it at the poles for water, but not a mention of the lunar daylight issue.

    At the poles, I could see this having a chance… put it on a mountain peak and you’ll have sunlight almost year-round. However, that would work in only a few polar peaks; the moon’s orbital plane around the earth is inclined by about a degree and a half to the plane of it (and earth’s) orbit around the sun, so you’d need a fairly high peak, even at the pole.

    For for anywhere else on the moon, you’re looking at very long, cold nights indeed.

  10. Trent, did you read more than half of Arizona’s post or did you stop as soon as you had read enough to snark about?

  11. NASA funded long term space flight research programs have turned out some rather spectacular nutrient film transfer growing systems. One that I find intriguing is a aeroponic style system with a root container that maintains a heavy fog to supply the water instead of a conventional sprayer, drip, or deep water culture system. In such a system water could be closely regulated down to the drop. Also, It wouldn’t need gravity to help with water dispersion and drainage. I imagine you would see some incredible growth rates as well. Where possible natural sunlight would the best option but an LED or plasma lighting system would also be good to have on hand as an augmentation to your lighting needs. These lighting systems would be able to maintain high lumen levels without replacement over a long period of time.

    You wouldn’t be able to just plop a greenhouse down with a transparent roof in a 24 hour sunlight environment and really expect to grow anything other than trees or shrubberies. For fruiting plants darkness is just as, if not more important than the sunlight you provide. And many vegetables, like lettuce, actually grow pretty darn good in partial shade or overcast situations rather than full on blazing direct sunlight. You’d need some type of shutter/shading system, mirrors to redirect the light straight down instead of from the side (if growing at the poles) or, like in the OP article, piped in light. It’d almost be a wash in terms of complexity to just assemble a full capacity artificial lighting system. You’d be able to maintain lighting schedules with a flick of a switch.

    Also, your supplies of fertilizer would be a concern. Yet another reason to start heading out to asteroids right now to see if we can find any organic compounds floating around out there. Not only would water be a precious commodity but also your access to nitrates, phosphorous, and potassium would be vital.

  12. But I’ve heard some vitamins, such as C, have long term stability problems in storage.

    Algae are great for that, especially Spirulina. Too much single-cell protein is bad for humans, but apart from that it would almost be good enough as complete source of food. Well, that and the taste probably. It’s perfect as a food supplement (or fish feed) however.

    The reason too much SCP causes gout is that humans, unlike many other mammals, cannot break down uric acid.

    Also, your supplies of fertilizer would be a concern.

    Mostly bioregenerative would be great. Resupply of part of the inorganics wouldn’t be too bad, but most of it can be recovered fairly straightforwardly.

  13. Pete and Ken:

    When I wrote to Mark Holderman asking for further detail about NAUTILUS-X, one of the things he told me was

    Thermal management is a major technical consideration that has a couple of nifty solutions that are being pursued. One of the inflatables will have a decidedly green element associated with it….[think Silent Running w/ Bruce Dern]. It is a partial thermal shunt, not the complete solution. Radiators will still be required, along with some new Variable Conducting Heat-Pipes that the old Hughes Aircraft Corporation had utilized.

    Ahh, the subtle interplay of science fiction with space cowboys…

  14. Too much single-cell protein is bad for human

    MPM, spirulina has a large nucleus which is high in nitrogen (due to the mass of DNA in the nucleus). That is what can cause gout. While I don’t think anyone has yet fixed the problem, the current approach seems to be that one can mechanically separate the nucleus from the rest of the spirulina cell. Doesn’t sound very viable for a small Mars expedition, but that’s one possibility.

    Another is to get something more edible to eat the spirulina and deal with the excess nitrogen for you. Some fish (such as tilapia) and shrimp can do this.

  15. Yeah, that seems to be the thinking. Spirulina as a food supplement and tilapia feed. Higher plants and tilapia as food for humans. Some small amount of inorganics replenished from Earth.

  16. PS It’s not the nitrogen, it’s the purines in DNA and RNA that lead to heightened uric acid levels. If I’m not mistaken excess nitrogen leaves the body through natural paths without too many problems. Urea naturally decomposes into ammonia, which can be nitrified to nitrite and then to nitrate, which is an excellent source of nutrients for plants and algae.

  17. I think something like 35% of tilapia is yielded in fillets, I suspect the rest could be fed to salmon. Fish have very good body mass from food conversion ratios – cold blooded and floating around consumes very little energy (something like 1.5-2x, compared to say 5x for pigs – not sure if this is wet or dry mass though). Algae is up to around 7% efficient compared to 1-2% for land crops. By my figuring the yield of edible fish per area could exceed that of wheat, etc., also, no irrigation/dehumidification required.

  18. We aught to be able to provide enough supplies before the first colonists arrive on mars, then let them figure it out. I expect the fishing to be good. Send everything we can think of and try it all out. Keep whatever works. They’re really shouldn’t be any problem keeping them alive for the first decade while they figure out what works.

    Using the mars rovers as a guideline, it cost about $2b per ton to put supplies on mars and I’m sure we could do it cheaper. A ton could be a lot of diverse supplies. At 4kg per day for consumption that’s about 250 days of consumables per person per ton. $20b in supplies seems pretty cheap for half a dozen people to figure things out in exchange for an entire world. Once they do, it cost a lot less for all those that follow.

  19. a suitable mix of microbes introduced to moistened pulverized granite or similar will produce good soil if you wait long enough

    Perhaps, but live soil is a complicated mix. I think we need to send some as a starter kit. Create the closest local analogy, then mix it with the real stuff and see what happens.

  20. “Urea naturally decomposes into ammonia, which can be nitrified to nitrite and then to nitrate, which is an excellent source of nutrients for plants and algae.

    I believe ammoniacal nitrogen becomes depleted rather quickly when used as a fertilizer. Nitrate nitrogen is generally the best source of nitrogen for fertilizer. One good reason to have fishes along since their scat is loaded with it. Buuttt that is one downside of a aeroponic system is they tend to clog up when using organic based fertilizers. Pure chemical fertilizers that are free from bacteria tend to reduce the accumulation of slim and crusty salts that can clog up aeroponic/hydroponic systems. Soil provides really huge yields but grows slower and takes up more space. Not to mention the soil would be heavy.

  21. Fish have very good body mass from food conversion ratios – cold blooded and floating around consumes very little energy (something like 1.5-2x, compared to say 5x for pigs – not sure if this is wet or dry mass though).

    Insects are also excellent sources of protein.

  22. I believe ammoniacal nitrogen becomes depleted rather quickly when used as a fertilizer.

    I’m definitely not an expert, but I’ve been reading up on regenerative (not necessarily bioregenerative) life support systems. I think ammonia may be too volatile to be very useful under an open atmosphere on Earth. But even in a closed habitat in space nitrate is still preferable to ammonia as it is a better source of nutrients for algae and higher plants. The ESA Melissa projects uses bioreactors with soil bacteria to convert ammonia resulting from processing of crew (or fish) waste and inedible plant waste
    to nitrite and the resulting nitrite to nitrate. Dealing with ammonia is not a problem at all. The problem is with the earlier stages, where solid waste has to be converted to something the bacteria can handle.

    There are several brute force alternatives for these first stages: supercritical water oxidation, incineration and pyrolysis. The first two break the waste down to totally harmless and recyclable N2, CO2 and H2O. They are very straightforward technology, but also very heavy because of the high temperatures and pressures involved, which makes it more difficult to do in space. SCWO also has to deal with corrosion problems.

    Pyrolysis produces a direct stream of more complicated chemicals, including ammonia, and is more energy efficient, but also needs more processing steps to deal with these chemicals.

  23. This talk of tilapia and nitrogen fixing got me thinking about a study I read a while back about increasing rice production in the Phillipines involving rice, tilapia, ducks, and azolla. It turns out when all four are present, the food production of rice, fish, eggs and ducks were all higher than if one of the four was missing. The azolla (a nitrogen-fixing aquatic fern) spread out over the surface of the water, shading the rice’s roots and crowding out any weeds. The fish and ducks ate parasitic snails from the rice plants and also ate the azolla, and when the field was drained the azolla settled to the bottom and fertilized the soil, along with the duck and fish crap.

  24. Well in the near term I think that dry mass chemical fertilizer feed stocks will do well to serve as a cargo to hoist up into orbit on low cost, low survivability launchers. This will help decrease the cost to orbit since not only will we need launchers to boost essentials like oxygen and fuel into orbit but also cargo food stuffs. This is probably why the current space tech is focused on putting pre-processed food packages into orbit rather than the precursors to food production. The weight and cost to orbit is on par to make it most sensible to just cook the food here and then send it into space. If we drive the costs down and increase the population of people into space enough then growing food on the other side of the atmosphere will become more cost effective.

  25. Absolutely Josh,

    increase the population of people into space

    There is always the growth curve (assuming we go at all?) With the fact that the first to go can prepare for those that follow. Suppose it cost $60b to send a dozen people to mars one way ($5b each.) Using the exact same ship (model 2310V7.15) you could then send 100 people (deluxe cabin 18 m^3) then 200 (standard cabin 9 m^3) then 300 (econolodge 6 m^3) with 510 m^3 of common area in each configuration.

    Ticket price per person to mars: Dlx: $170m Std: $85m Eco: $57m plus an additional $40m regardless of cabin size (Dragons and mars lander got to eat too.)

    This assumes we leave each perfectly good refuelable ship in mars orbit because it’s cheaper to just put a new one in earth orbit. Mars will have a lot of space stations for free. Depending on how long they take for a martian SSTO to unload them, they may still have extra supplies waiting for the later arrivals.

    I’m assuming 4kg of consumables per person per day. Waste elimination I haven’t given much thought about but with 300 people on board I assume it’s a major issue (eject it, burn it, recycle, what? Power requirement?)

    Everything but the mars lander currently exists and provided the numbers I’ve given. There will be farmers.

    That’s also assuming current fuel costs to orbit using the most expensive figure I could find. Better efficiency and flight rates would bring that down.

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