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Growing Crops on Mars: Hydroponics Beyond Earth · Hydroponics Daily

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Hello there and welcome back to
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Hydroponics Daily, your go-to podcast for everything soilless cultivation.
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Normally I come to you with a really practical episode about how to grow plants hydroponically.
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Today is completely 100% impractical and that's because we're talking about
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how to grow crops on Mars.
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And if you've ever watched The Martian and if you thought how did Matt Damon
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ever manage to grow potatoes,
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we'll talk about the science behind that, the theories and what the current
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thinking is on how crops might be growing on Mars. If you've got any ideas, please comment.
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this on YouTube and you've never seen or listened to any of my podcasts,
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I've got over 200 episodes on a different hydroponic subject every single day of 2025.
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And they go from the complete beginners all the way through to expert level
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so today we're talking about potential of
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growing crops on mars i'm not going to cover how you would
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get astronauts from earth to
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mars and feed them there i'm going to assume that's already been done we're
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going to talk the practicalities of mars specifically not other planets not
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space bases not moon bases and there's lots to one pack it's going to be a real
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deep dive into that today okay so the first thing the most important thing for life,
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the reason Los Angeles is where Los Angeles is and Benidorm in Spain is where
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Benidorm is, it's not because they're great locations, it's because the most
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valuable resource in the world on earth is there and that's fresh water,
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clean water you can use for crops and for growing plants.
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And so that will be the first.
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Factor when looking for a location to cultivate
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plants on Mars and there are
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some downsides because where the water is might not be the
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best place to grow plants so if we
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think about the best locations Mars has been
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found at the poles however you've got a trade-off
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there with the latitude so a Mars year is extremely
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long look at my notes 687 days
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and I asked chat GPT how
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many days a year at the poles could is
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there enough light to maintain photosynthesis to
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allow photosynthesis to occur and that's 300 to 340 days
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and so half the year there's not enough light
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of photosynthesis so we're not likely be
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growing with windowed based hydroponic systems
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there so but first of all you're going
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to need the water can you mine it can
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you purify it can you recycle it you you might
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look for mid-latitude regions with shallow subsurface
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locations there's one called utopia planeticia
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so that might be a good location and it's been detected by radar and neutron
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mapping but it has has water so it offers ice at diggable depths so the martian
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colonizers could get out there and dig so it's not just the poles the problem
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with the poles is as i I said that you've got those brutal winters.
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Imagine an Antarctic base and then times it by 10.
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And you've got more stable light there the seasons
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are more extreme on mars as well so the
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light levels differ by up to 40 percent based on
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on season there is potentially you
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could potentially have two bases you could have one on the north
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pole one at the south pole and you could just flip between
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the two and always be in summer a bit like what rich people
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do here in the uk and over here in safe africa
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for the winter or australia what a
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fantastic life when it comes to the light and
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all the intricacies that come with light it's not just having light
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that's important it's the amount of light so mars on
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average gets about 43 of the light from
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the sun that we get here on earth and
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the day length the length of time is roughly similar
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so a sol a martian sol which is equivalent of a day
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is 24 hours and 39 minutes so
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plants will be fine with with with that and
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the growth levels would be lower that amount of light levels obviously the
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mid winter time would be the
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plants would be dormant so there's a
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big issue around how would we grow plants on mars and you probably wouldn't
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use sunlight to grow directly for photosynthesis if you look at a lot of the
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science fiction literature and films things like this they've often got windows
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in the colonies and things like this,
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but windows are fairly impractical.
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You think about the weight required for a reinforced window to survive the harsh
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Martian windstorms and dust storms.
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They'd get covered in dust as well. They'd have to be transported.
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You can't 3D print a window. It's made of silica. You can't yet, I don't think. And.
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Also, if you compare that to just using LED or whatever the next generation
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of lighting is, whatever is around when they colonize Mars,
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then you could just use a solar panel or probably more likely a nuclear reactor
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to actually power the lighting system. So that would be far more practical.
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So it's more likely they're grown indoors using artificial lighting.
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Also, So the other factor to consider is that Mars has two moons,
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so any of those biodynamic hippie astronauts and colonizers wouldn't need to
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decide which moon to prune and sow and germinate on. That's a bit of a joke, obviously.
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Biodynamics is a load of nonsense. If you ask me, there's that option.
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And then there's the other option, could you use artificial photosynthesis or electro agriculture?
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We talked about that briefly on another subject. It's where
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you convert CO2 and electricity into something called acetate
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and you grow organisms with that
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acetate sort of gm genetically modified plants that
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can feed off this acetate can be grown in the dark
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or in just like light levels in a in a colony
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you don't need grow lights it's very
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much at an early stage this technology of using
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acetate as a carbon source as a food source for plants but
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it's something that i think one of the musk brothers has looked
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at or even elon might even be looking at so it's
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it's an area of interest both in human consumption
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here on earth and on on mars so
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yeah something to consider i would imagine most researchers
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are looking at led lighting though currently and as well as plant growth is
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look at the growth of yeast algae and fungi as well as to grow to grow food
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a bonus idea could you grow under ice ice can filter out damaged uv without while passing.
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Photosynthetically active radiation through potentially creating
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a light well in some settings it's still speculative not sure if this could
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be happening on mars but it's intriguing for polar regions perhaps you could
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build a or you could spray a an igloo and grow inside a hermetically sealed
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igloo so that's something to consider.
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You know life gives you lemons make lemonade if life gives
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you extremely cold planet then make an igloo
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to grow your crops in so obviously the
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title of this podcast is hydroponics daily and we
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focus on hydroponics and you might think well do they
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have to grow hydroponically on mars well there's no
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soil on mars and that's because
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it might contain dust but soil by definition
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is something that plants grow in so on mars
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on the moon there is no soil there is
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something called regolith and we could
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potentially use that as a grow media for hydroponics
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now some sorts of hydroponic systems
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you wouldn't require any grow media anyway
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so you could do without the regolith so deep water culture where
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the roots are suspended in a rated nutrient
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solution simple stable but water
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heavy and could drive up the humidity in sealed
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habitats requires a lot of water so if you're if
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the mars colonizers are going to
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struggle to get water out and and clean it
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up and melt it then potentially
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dwc is is out of the question aeroponics
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is another option where roots hang in the air and then
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they're misted with nutrient solution using a mist or
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a fogger very water efficient compared to
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dwc fast growth but demands reliable
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nozzles filtration and redundancy and.
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In a mars system everything has
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to be fully reliable and bulletproof
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because you don't want a sad ending to
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your mars colony film do you so likely
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picks for me would be nft nutrient film
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technique or probably ebb and flood where you could fabricate channels and trays
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using 3d printers and that would keep biofilms in check and you could make fairly
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simple systems and you could use the regolith as a growing medium for that.
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Also, when you think about hydroponic systems, obviously, this is going to be
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fully controlled for EC, pH,
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relative humidity, leaf temperature, VPD, light levels.
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Nutrient dosing, and AI-controlled systems, freeing up the colonizers to do
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other fancy things with their time, building out the habitation places and doing
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experiments with their scientists and things like this.
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So crew time would be precious and automation would be important and
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you think about 3d printing printing manifolds trays
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spray rails brackets spares feedstocks
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compare that to sort of transporting bulky
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finished hardware for years from
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earth to mars trying to play sort of like 3d tetris
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trying to pack it all in into a rocket that would
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be virtually impossible so it's probably going
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to be 3d printed all that and then the big question
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when it comes to mars colonization is
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can the regolith become a growing media so
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what does the regolith offer did the sort of dust the rock on mars
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well it's it's basaltic like basalt rock
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which means it's rich in magnesium calcium potassium
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iron and silicon and there
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is also a location on mars
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that's been found where nitrates a key
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macronutrient have been found the gale crater
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was found by nasa by one of the rovers curiosity rover and so there's potential
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for using that now that might not be the the gale crater might not be the best
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place for habitation so you might not be water there so you might need to go
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and quarry that and bring it back things like that that might be one of the missions on mars.
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So those are five key elements there, plus nitrogen, but you're going to also
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have to add other nutrients that the regolith is short on, so phosphorus,
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sulfur, and all the macronutrients, like apart from, what did I say,
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iron, so boron, zinc, copper, molybdenum, manganese, etc.
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Chlorine, sodium, they wouldn't be an issue because humans will piss those out.
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And in a recyclatory water system, there'll be loads of those anyway.
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But it's also very poor thought
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to be porous so um that's a good thing for the
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regolith now what are the downsides of the regolith well there's one massive
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downside and that contains perchlorites and
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other oxidants these are compounds that are extreme
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oxidizing agents and they will
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kill roots plant roots and they'll kill humans and
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so they will need to be removed they can be removed just
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by if there was lots of water available and they found an easy way to
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remove it to extract water on mars they could
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just leach that just pour water through the
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regolith before they use it for as a ground media they could
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heat it to 200 to 400 degrees celsius so if you've got a nuclear reactor on
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site for lighting and heating and things like this then that potentially that
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could that could heat the regolith for that or if there's a hydrogen source
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you could chemically reduce the oxidizing agents by adding hydrogen gas.
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Or you could use perchlorite-reducing microbes in a bioreactor.
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And that's the basis of the plots of the Martian.
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Although it's not made super clear in it, Matt Damon
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is harvesting his feces and
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culturing it with the regolith to make the
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bacteria break down the perchlorite so that it's suitable for growth
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of the plants and also for cycling nutrients as well so it's
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mentioned in the book pluricolorites but it's not mentioned in the film
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because it's you know go over most people's cinema
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goers heads but that would be one of the key things
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that would need to be looked at other disadvantages of
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regolith is it's got high ph so between eight
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and nine it's got some aluminium in there which are
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not great for plants there's no organic carbon and there's dust in
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there that could clog the roots so they are minor
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of disadvantages and you know if you use a fertilizer like liquid
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gold as i've said we've manufactured that or gold leaf as it's known in the
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us then there's no issues there because that will drag the sweet spot way down
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to between 5.5 and 6.5 the other advantage of using a fertilizer like i said
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like gold leaf the unique one part fertilizer is that.
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You don't need to worry about A and B fertilisers and you don't need to be transporting
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pH up and pH down all the way from Earth.
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So I would definitely recommend NASA when you colonise, get on the gold leaf
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as it's called in the US or liquid gold.
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If the UK space agency gets to Mars first, highly unlikely, but there you go.
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The other issue around the dust, I mentioned the dust there that could block
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roots and block filters and things like this,
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probably a bigger issue for HVAC systems and if the dust got in there's a lot
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of dust on mars and if you're breaking up regolith to make grow media then that
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could be an issue so you would need to wash and re-dust it this is an issue
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around magnetic magnetic issues around the grow media but i'm not too sure about that.
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So we've talked about the regolith the nutrients so you want a reliable one
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part fertilizer it's got to be reliable it's got to be bulletproof and we've
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tested our products on you know thousands but not thousands hundreds of crops
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so we know that it works so or you could go we talked about,
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aeroponic nft to remove the need for a substrate atmospheric management on the
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farm so co2 what's going to be a co2 strategy the crew will be exhaling co2
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and water and you could take that and then and use that to feed the.
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The grow room be scrubbed or could be
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put into algal bioreactors as well or you
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could there's a high co2 level on mars and so you could
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be using co2 from the mars itself the oxygen
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levels are very very low on mars so that's something
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we need to look at and oxygen is
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required for germination so even
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if you manage to get the plants to grow outside by some
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crazy gm feet you probably you you
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definitely need to bring them inside into a human habitation for
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germination because seeds won't germinate without good
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levels of oxygen what about humidity and condensation
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well the humidity would be extremely low outside and
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could be very high inside so heat recovery
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dehumidifiers to reclaim transpired water from
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both the humans and the plants you want a near closed
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loop system there and then thermals one
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of the other did i mention this when it came about the windows basically terrible
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insulation windows and poor physical strength so
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you want heavy insulated to prevent the on the
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habitat skin the waste heat from the lights and
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gears could help heat the the habitation
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your roots would need to be kept warm as well
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so the can just put them straight into regolith
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that's in in the ground because it would be freezing cold
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and your roots would get damaged just like when you situate a.
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Grow room in say like a greenhouse and
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you heat the air in the greenhouse but if it's really cold outside the concrete
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floor can can really damage the roots if you put them
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straight on it so you might get a similar situation what
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are you actually going to grow on mars well you want
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to grow fast forgiving staple crops
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that provide lots of nutrients and lots of calories that's going to be your
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first need if you think about maslow's hierarchy of needs being getting the
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calories in is the first thing then getting the vitamins in would be the second
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need so you're going to be looking at things like potatoes potatoes you just,
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put a seed potato in the regolith and eventually it'll grow and produce more
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potatoes there's no need to think about flowering and fruiting and pollination
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and it'll produce lots of calories,
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fairly quickly whereas for nutrition and vitamins then you look in microgreens
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culinary herbs and things like
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this that will produce lots of leafy greens give you folic acid and then.
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In your hierarchy is you go up to more like
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psychological requirements you know
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you could feed yourself on potatoes and lettuce but would you stay sane if you
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did that so the other option for helping the colonizers stay sane and and having
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an enjoyable time is letting them choose what crops they grow and then letting
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them having some flavor as well so things like strawberries chives, mints,
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chilies and tomatoes, things that they would recognize from home and give flavor
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to the plants rather than just being boring and bland.
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And then obviously if you gave them a choice out of 10 then they feel like they've had a choice.
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Psychologically having a choice on something is very important.
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Obviously pollination,
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there's no insects on Mars so you could use things like
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the colonizer's electric toothbrush or handheld vibration
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for pollinating certain crops like tomatoes and peppers
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or just grow crops that don't require pollination so lack of pollination is
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a bad thing good thing is that there's no pests or disease on mars but you need
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to make sure it stays that way so that all of all the propagation material the
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seeds or the seed potatoes would need to be produced in a very very sterile
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conditions for a number of life cycles before they go to mars,
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you want menu diversity as well so colonizers have a choice of a menu as well
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as just a different choice of plants and,
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you might grow ornamentals, shade-tolerant ferns or flowering plants in the
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areas with lower light levels just to give a psychological effect.
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You know, some people say you don't need ornamental plants, but,
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you know, like Chairman Mao tried to get rid of all gardens in China during
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the Cultural Revolution.
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But then you find that plants have an important psychological effect, ornamental plants.
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You know, there's lots of people in the UK who say, you know, we
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should dig up council gardens and plant just food plants for people to eat like
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something's like some sort of utopia where people would just eat apples and
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the apples wouldn't just fall on the ground and get eaten by rats ornamental
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plants play a very important part just like art and music you wouldn't say well
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well the martian colonizer is not going to listen to music because it uses valuable.
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Electricity it's part of being human and then you'd
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have to have crops that could be stored easily and robustly
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through the martian winter and potatoes is obviously great
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for that because they can be stored in the dark and
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in a wide variety of conditions or legumes and microalgae potentially you could
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have bioreactors and things like this so there's potential for that now could
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you grow outside on mars that's a big question there are a lot of challenges
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to growing outside on Mars. I made a list.
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Where's my list? I can't find it.
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Lots of environmental killers. So there's almost no atmospheric pressure,
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so that could affect the plants.
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Extreme cold, so you could potentially genetically modify a plant to tolerate some of these factors.
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So extreme cold, desiccation, the complete lack of humidity,
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the oxidising agents in the regolith, we talked about the perchlorites.
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Extremely high UV light because there's no real atmosphere there.
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Dust abrasion from the windstorms the lack
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of water well you would be adding water otherwise the plants just wouldn't grow
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even a super plant would need to have a lots of different
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factors stacked on top of it
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you know a winter dormancy as well that's another one and so
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you would you very very
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unlikely you could grow outdoors on mars however as
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well as sort of gm crops there's also the potential for terraforming
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mars you might have heard of nuke the poles where
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this idea that you would send a load of rockets or
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missiles containing nuclear warheads and release
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them and set them off at the poles that could release co2 to
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warm mars and melt some ice caps the snag
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there is there isn't enough accessible co2 on mars meaning for to meaningfully
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thicken the atmosphere with today's tech even if you tried so but the idea would
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be that you just put hundreds of nuclear weapons and get rid of them put them
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on mars somewhere safe and by exploding them and then eventually things like algae,
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microalgae could potentially grow and then you could colonize thereafter.
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So that's something to consider. How would you power the farm?
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So we talked about nuclear fission and solar arrays, batteries, flywheel.
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You know, there's a lot of storms there. You could have like.
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You could have a wind farm, things like this.
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At the moment, LEDs, we said, are winning because of the precise spectra,
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high efficiency, dimmable, and photoperiodic control.
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But there might be a new technology by the time it comes to colonize Mars.
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Just jumping back into environmental controls one thing
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that i think i missed is that you wouldn't
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need to have really high oxygen
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levels in the growing environment because plants don't
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need lots of oxygen when they're photosynthesizing so
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potentially you could have two different habitats you could have the
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habitat for the plants and the habitat for the humans so this could mean
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that the marshal colonizers have to wear space suits
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or protective suits when they're harvesting and tending the
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plants because why create or put all that
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energy into creating oxygen rich environment for
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the plants if it's not needed it's only needed for the farmers so they
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could wear spacesuits whilst they're harvesting it and they
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could go into a different pod for living and
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sleeping and entertainment and then have a separate pod
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for farming in where it was 1000 ppm co2
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but low levels of oxygen and then only need
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use the oxygen rich environment for the plants when they need to germinate some
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seeds and things like that so there's potential there for some saving on habitat
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environmental highly energy intensive and resource intensive systems there you
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don't need an oxygen rich environment.
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So how would you put that all together? Well, the site, probably not at the
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poles if you want a single site.
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Mid-latitude, where there's shallow ice. So that site called Utopia or the Arcadia
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zone could be a potential.
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However, you're still going to have a very long winter. So I'd probably have
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two polar systems rather than just one.
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Structure, you could have it buried or a permed pressure hull.
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No windows, as we said. It's probably not going to be likely. radiation shielding
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and the regolith will help with that
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water wells and service corridors
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to separate the plants from the humans because
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they want different things maybe an aeroponic system
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or an nft system with cleaned regolith combined
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with a fertilizer you could potentially use bioreactors to
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grow algae and fungi and yeasts and
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other things as well as plants and obviously
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the outputs so the inputs are the mined
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ice power from the reactor fertilizer like
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cold leaf it's one part fertilizer trace supplements
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potentially co2 from the crew or all
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from outside and then the outputs
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leafy greens potatoes you know leafy greens
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you could get daily potatoes you know
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potentially weekly after a while and then
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other things like herbs and spices and things
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to flavor them afterwards and then obviously
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some way of removing that perchlorate the
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key factor is going to be robustness you don't want
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to have a story for a science fiction disaster movie playing out before you
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you want to have robustness and probably fail safes embedded into the system
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because this is what there's no crew coming to rescue you there's no.
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Reinforcements coming for years thanks very much for tuning
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into hydroponics daily today i've been your host
25:04
dr brussell sharp and as i say this is a podcast
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Thank you very much for listening. Until tomorrow, goodbye.