A recent preprint posted to bioRxiv investigates how chickpeas have been successfully grown in lunar regolith simulants (LRS), marking the first time such a guideline has been established not only for chickpeas, but also for growing food for long-term human space missions.
I do not understand the point of these experiments. They’re nitrogen fixing with Arbuscular Mycorrhizal Fungi. Why not just do it hydroponically? It’s not like you’re going to try to fix atmospheric nitrogen on the moon to create soil.
But isn’t the point to make the regolith into something other than murder dust?
For complex plants, you essentially never will.
The point of these experiments is to find out what will happen.
Which btw is the point of all experiments.
Hydroponics requires biologically available nitrogen too and it has to come from somewhere. The point of these experiments is to explore a wide variety of scenarios. Hydroponics as a growing method has some drawbacks too. Any robust food production scheme in space will likely include a mix of hydro- and geo-ponics (fancy name for soil growing).
Also consider the non-food benefits of living plants and soil. Any long term habitat on the moon or Mars will need living plants for the psychological and air quality benefits. There is a massive body of research that shows the benefits of having trees around. There is even research that shows just smelling healthy soil can be antidepressant.
Let’s say we enclose a large lava tube, one seriously considered approach for long term habitats. Having some greenery would go a long way to staving off Space Madness.
Makes sense that if you can plant plants in a plantable media, over time you may develop that media into something akin to soil, which means you have a more stable grounding for future generations of plants.
(I honestly tried for some alliteration or punnage, this was the best I could do, forgive me 😄).
Yes, I’d think that would be the goal. Long term habitation will need plants of many kinds. Just start listing all the ways people benefit from plants and you’ll see the list just goes on and on. At the huge price per kilogram of launched mass, making soil out of local materials and developing closed-loop systems just makes economic sense. Soil is a living thing after all, it doesn’t wear out or go away. (Older than dirt!) Learning how to make healthy functioning soil from native regolith is an important part of the whole in-situ resource utilization push from the major space agencies.
Exactly.
We already do a lot of research on earth to maintain and improve soils, such basic things as turning under a winter crop which is used as a fixative, making that soil healthier.
Seems like it could work with regolith (as in these tests) - turn each plant generation back into the regolith, composting it, eventually it becomes soil with everything being retained.
It’ll be really interesting to see the plant growth and soil improvements over the generations of composting (which I assume is part of this testing).
“Older than dirt” lol, yep!
https://en.wikipedia.org/wiki/Azolla_event
So I think Azolla (a floating fern that fixes nitrogen) is the way to go to jumpstart an extraterrestrial soil. It’s insanely productive and makes amazing compost. The wikipedia link is just a cool thing I like to share.
MADNESS IN SPAAAACCCEEE
It’s like regular madness, but in spaaaaaaaaaaace, therefore very expensive.
Well you have to make sure the madness is hardened against cosmic rays.
I am not familiar with what is required for hydropony, but I would guess it requires more equipment. Plus growing them on Lunar soil means eventually you get some elements from the Lunar soil itself and do not need to have full recycling otherwise, which means you don’t have to have a fully closed cycle for this.
There is still the issue of the closed cycle for air though (which is where Mars is easier than the Moon for medium term colonies).
Seahorses on the moon
I’m not an expert, but as a lay person I agree with you.
However, I’m guessing people running these experiments are just looking at all the options. Hydroponics is pretty much a solved solution, no? I suppose it makes sense to run these experiments to prove what we already know. I suppose there is a hyper slim chance that lunar soil was somehow beneficial for the plant and made growing easier.
I think the nitrogen issue is probably secondary to the water issue. Hydroponics use way less water. Water is heavy and expensive to ship to the moon. Anything to reduce weight will probably be the priority.
I don’t see how shipping more soil and more water would be better than hydroponics, but sometimes we write papers for problems we don’t have yet, but might have in the future. Some moon colony might be struggling for physical space and need to use soil to grow supplies in an emergency? Might be nice to know they can reserve some moon land and follow these guides to produce food in the soil.
My wife got her PhD in Physics and one of her favorite anecdotes is the critical piece of technology that made her project possible was derived from a mathematical paper written 200 years ago. The dude didn’t have the technology or science to know where his math would be useful, but he published it anyways. Eventually, someone needed it and found it useful.
¯\_(ツ)_/¯
I don’t think we’ll be shipping water to the moon.
Fortunately it has plenty.
Moreover, it’s easier to ship energy sources (e.g. nuclear, which today are small heat generators) and use that energy to get to the water that’s there.
I wouldn’t ve surprised if there have been numerous studies of how to get full-scale nuclear generation going on the moon, by launching a reactor in modules. I anyone has a link, I’m curious to see what approaches have been considered regarding launching a core, safely.
The one thing the moon does have, thankfully, is water. That means oxygen, water, and hydrogen are provided once you’re there as long as you have power. Essentially, the whole point of colonizing the moon can be seen as a source of water outside of the gravity well for engine reaction mass, radiation shielding, and oxygen. Nitrogen and carbon, unfortunately, you gotta ship, though you can get both by recycling it from pee and the air respectively. That’s why I mention hydroponics, because getting bioavabile nitrogen from pee is a chemical process.
Granted, I am a nurse. Botany and hydroponics are not my wheelhouse. These regolith experiments people keep doing just seem to be going the wrong way.
Agreed. I work in plant science and I always think these experiments are lowkey stupid and deliver obvious results lol.