Backyard Aquaponics
A place to discuss aquaponics

I had a really interesting discussion at lunch time about whether you could run Aquaponics in the void of space. I had a rant on my blog (http://www.athoughtadrift.com/gemmell) about some of the challenges. Rather than detail them, can anyone think of a real show stopper? I think a bit of creative engineering could overcome most problems.

It's certainly blue sky dreaming (or maybe black sky dreaming?), good fun.

Yeah, sure all you need is Oxygen, water, gravity, CO2, power supply(solar), fish food and all those other things that bacteria like.
Just like we have here on earth in the void of space!!


Cheers ianK

What about capiliary action? Plants need this to be able to get water from the ground to the leaves. Being in a vacuum would prevent capilliary action from working.


I dont know if this is actually true, but I tried to sound like I knew what I was talking about

There has to be a scale at which it works - after all, we're in space too!
I thought right away of the building method Larry Niven wrote about:
Find a roughly oblong mostly-metallic asteroid and bore a hole thru it along the axis. Put ice in there and weld the ends shut.
Now just start it spinning, while a big mirror concentrates sunlight on it.
It melts from the outside in, and when the heat gets to the inside, steam blows it out to a nice even capsule shape... hollow, spinning, and some water is already inside.
For an aquaponics farm version of this, you'll need some windows to admit light and terraces for the gravity-assisted water flow.

Hmmm. And now back in the real world. This is something I covered about 20 years ago with the eminent UK Science Fiction fan and Bio-chemist Dr Jack Cohen. Luckily enough he is a friend of the family and I've known him since I was about 10. (wow thats over 30 years! Man, I must be getting old.)

Gemmell, you cover a lot of points in your blog but I'm going to stick to a few important ones.

Vacuum:
Being in a vacuum would prevent anything from working. Water would become ablative. Long story short. Nothing can grow in the vacuum of space.

Gravity. Yes fish do need it. It's part of their biological nature to be able to determine attack threats. These are normally from avian predators and other aquatic predators (Pike!). Their colouring matches this biological need. Ever wondered why fish are darker on the top than the bottom? It to help camouflage them. Putting them in a zero-G environment would severely stress them give less growth rate and probable shorter life span. So they would definitely need a gravity environment.
In one of the discussions about space habitats we agreed that the probable best concept is an O'Neill Cylinder. One possible thought was if the glass panels needed to allow sunlight to enter could be used as water beds where the fish could swim. But this was again ruled out because of the above argument. Fish wouldn't like the sunlight coming from "below" them.


Light and heat can be had from the sun. No clouds to block the view so it could be regulated a lot better than here on Earth. Filter out the radiation, UV and other nasty particles and we have a plentiful supply. And as for terraces? No. In a spinning cylinder you have the benefit of allowing water to actually go uphill (in a manner of speaking). The water would tend to want to stay still, but with the high velocity of a O'Neill Cylinder the rotational cycle would be high enough that water would be able to "flow" slightly uphill. We could use that as a form of "pumping" the water around the system. To such an extent that we wouldn't need a traditional pump (except for air).

All in all, it really is a possible concept. Of course the problem is, whos going to put the damn thing out there in the first place?

This discussion reminds me of the time I held up an entire sience lesson in high school by asking the question... "So miss.... Can you freeze fire?" in the end the teacher just agreed with me that you could so that she could get on with the lesson she was supposed to be teaching. Wasted a good 30 mins of class time though!

Thanks for the great reply - mind if I copy paste it as a comment on my blog? It's informative.

Obviously you wouldn't do it in a vaccume - the entire thing would be pressurised.

I wonder how little gravity fish actually need. If it's just so they get a sense of up and down, maybe they don't need 9.8 m/s^2 - agreed they'll get stressed, but if they were born into lower grav, they might not get stressed by it. Or if you slowly reduce it (like a pH or temperature change). I love sci fi. Power and pumping really aren't a problem - solar cells work well, and pumps are effective enough.

Maybe we should ditch fish and go with a "lesser" form of protein. Something a little further down the heirarchy. Yabbies, prawns, shell fish...?

What if it was on the moon or mars? Is that considered still in space? From our perspective I would have to say yes.

Go ahead. If I look closely enough, I might be able to dig out some of the transcripts from the old EasterCons where this sort of stuff took place. I'll always remember the "design an alien" panel I took part it. We created this huge Fungi like creature which eventually achieved sentience kind of like a neural network.



Not so much as you'd imagine. They could probably go to about 4th to 8th of Earth gravity. Ideal for the Moon I'd say.



The power part is easy. On the moon or orbitals, solar panels and battery vaults would work. On Mars perhaps wind power.



Considering the problems people have experienced here in the forums with Crayfish and Yabbies, I might venture to say that the easier option would be the fish. Also for transporting, it might be possible to send them along as eggs. Not frozen, but certainly have their life functions slowed down. We already have the technology for that part. Eggs to fry to fingerlings to breeding maturity, I think it's all rather doable.

I wonder if they took anything like that on the Mars Mission?