≡ Menu

Food production on Mars: Dirt farming as the most scalable solution for settlement

Colonies on other worlds are a staple of science fiction and an obsession for rocket-obsessed entrepreneurs, but how do humans go about the business of living long-term once they get to a place like Mars? Alex Tolley has been pondering the question as part of a project he has been engaged in with the Interstellar Research Group. Martian regolith is, shall we say, a challenge, and the issue of perchlorates is only one of the factors that will make food production a major part of the planning and operation of any colony. The essay below can be complemented by Alex’s look at experimental techniques we can use long before colonization to consider crop growth in non-terrestrial situations. It will appear shortly on the IRG website, all part of the organization’s work on what its contributors call MaRMIE, the Martian Regolith Microbiome Inoculation Experiment.

by Alex Tolley

Introduction: Food Production Beyond Hydroponics

Conventional wisdom suggests that food production in the Martian settlements will likely be hydroponic. Centauri Dreams has an excellent post by Ioannis Kokkinidis on hydroponic food production on Mars, where he explains in some detail the issues and how they are best dealt with, and the benefits of this form of food production [1]

Still from a NASA video on a Mars base showing the hydroponics section.

A recent NASA short video on a very stylish possible design for a Mars base (see still above) shows a small hydroponics zone in the base, although its small size and what looks like all lettuce production would not be sufficient to feed one person, and that is before the monotonous diet would drive the crew to wish they had at least some potatoes from Mark Watney’s stash that could be cooked in a greater variety of ways.

I would tend to agree with the hydroponic approach, as well as other high-tech methods, as these food production techniques are already being used on Earth and will continue to improve, allowing a richer food source without needing to raise animals. Kokkinidis raises the issue of animal meat production for various cuisines, but in reality, the difficulties of transporting the needed large numbers of stock for breeding, as well as the increased demand for primary food production, would seem to be a major issue. [It should be noted that US farming occupies perhaps 2% of the population, yet most commentators on Mars groups seem to think that growing food on Mars will be relatively easy, with preferred animals to provide meat. How many Mars base personnel would be comfortable killing and preparing animals for consumption, even mucking out the pens?]

Hydroponics today is used for high-value crops because of the high costs. Many crops cannot be easily grown in this way. For example, it would be very difficult to grow tree fruits and nuts hydroponically, even though tree wood would be a very useful construction material. On Earth, hydroponics gains the highly desirable much-increased production per unit area coupled with a very high energy cost. It also requires inputs from established industrial processes which would have to be set up from scratch on Mars. Should there need to be lighting as well, low-energy LEDs would be hard to manufacture on Mars and would, initially at least, be imported from Earth.

Hydroponics is attractive to those with an engineering mindset. The equipment is understood, inputs and outputs can be measured and monitored, and optimized, and it all seems of a piece with the likely complexity of the transport ships and Mars base technology. It may even seem less likely to get “dirt under the fingernails” compared to traditional farming, a feature that appeals to those who prefer cleaner technologies. Unfortunately, unlike on Earth, if a critical piece of equipment fails, it will not be easily replaceable from inventory. Some parts may be 3D printable, but not complex components, or electronics. Failure of the hydroponic system due to an irreplaceable part failure would be catastrophic and lead to starvation long before a replacement would arrive from Earth. If ever there was a need for rapid cargo transport to support a Martian base, this need for rapid supply delivery would be a prime driver [4].

Soil from Regolith

Could more traditional dirt farming work on Mars, despite the apparent difficulties and lack of fine control over plant growth? The discovery that the Martian regolith has toxic levels of perchlorates and would make a very poor soil for plants seems to rule out dirt farming. If the Gobi desert is more hospitable than Mars, then trying to farm the sands of Mars might seem foolhardy, even reckless.

However, after working on a project with the Interstellar Research Group (IRG), I have to some extent changed my mind. If the Martian regolith can be made fertile, it would open up a more scalable and flexible method to grow a greater variety of plant crops than seems possible with hydroponics. Scaling up hydroponics requires far more manufacturing infrastructure than scaling up farming with an amended regolith if regolith remediation does not require a lot of equipment.

So the key questions are how to turn the regolith into viable soil to make such a traditional farming method viable, and what does this farming buy in terms of crop production, variety, and yields?

The first problem is to remove the up to 1% of perchlorates in the regolith that are toxic to plants. While perchlorates do exist naturally in some terrestrial soils, such as the Atacama desert, they are at far lower concentrations. Perchlorates are used in some industrial processes and products (e.g. rocket propellant, fireworks), and spills and their cleanup are monitored by the Environmental Protection Agency (EPA) in the USA. Chlorates were used as weedkillers and are potent oxidizers, a feature that I used in my teenage rocket experimentation, but are now banned in the EU.

There are 2 primary ways to remove perchlorates. If there is a readily available water supply, the regolith can be washed and the water-soluble perchlorates can be flushed away. The salt can be removed from the perchlorate solution with a reverse osmosis unit, a mature technology in use for desalination and water purification today. In addition, agitation of the regolith sand and dust can be used to remove the sharp edges of unweathered grains. This would make the regolith far safer to work with, and reduce equipment failure due to the abrasive dust damaging seals and metal joints. Agitation requires the low technology of rotating drums filled with a slurry of regolith and water.

A second, and more elegant approach, is to bioremediate with bacteria that can metabolize the regolith in the presence of water [5,6,7,8]. While it would seem simple to just sprinkle the exposed Martian surface with an inoculant, this cannot work, if only because the temperature on the surface is too cold. The regolith will have to be put into more clement conditions to maintain the water temperature and at least minimal atmospheric pressure and composition. At present, it is unknown what minimal conditions would be needed for this approach to work, although we can be fairly certain that terrestrial conditions inside a pressurized facility would be fine. There are a number of bacterial species that can metabolize chlorates and perchlorates to derive energy from ionized salts. A container or lined pit of graded regolith could be inoculated with suitable bacteria and the removal of the salt monitored until the regolith was essentially free of the salt. This would be the first stage of regolith remediation and soil preparation.

There is an interesting approach that could make this a dual-use system that offers safety features. The bacteria can be grown in a bioreactor, and the enzymes needed to metabolize perchlorates extracted. It has been proposed that rather than fully metabolizing the salt to chloride, enzymes could be applied that will stop at the release of free oxygen (O2). This can be used as life support or oxidant for rocket fuel, or even combustion engines on ground vehicles. The enzymes could be manufactured by gene-engineered single-cell organisms in a bioreactor, or the organisms can be applied directly to the regolith to release the O2 [10]. The design of the Spacecoach by my colleague, Brian McConnell, and me used a similar principle. As the ship used water for propellant and hull shielding, in the case of an emergency, the water could be electrolyzed to provide life-supporting O2 for a considerable time to allow for rescue [9]. Extracting oxygen from the perchlorates with enzymes is a low-energy approach to providing life support in an emergency. A small, portable, emergency kit containing a plastic bag and vial of the enzyme, could be carried with a spacesuit, or larger kits for vehicles and habitat structures.

After the perchlorate is removed from the regolith, what is left is similar to broken and pulverized lava. It may still be abrasive, and need to be abraded by agitation as in the mechanical perchlorate flushing approach.

So far so good. It looks like the perchlorate problem is solved, we just need to know if it can be carried out under conditions closer to Martian surface conditions, or whether it is best to do the processing under terrestrial or Mars base conditions. If the bacterial/enzyme amendment can be done in nothing more than lined and covered pits, or plastic bags, with a heater to maintain water at an optimum temperature, that would be a plus for scalability. If the base is located in or near a lava tube, then the pressurized tube might well provide a lot of space to process the regolith at scale.

Like lunar regolith, it has been established that perchlorate-free regolith is a poor medium for plant growth. Experiments on Mars Regolith Simulant (MRS) under terrestrial conditions of temperature, atmospheric composition, and pressure, indicate that the MRS needs to be amended to be more like a terrestrial soil. This requires nutrients, and ideally, structural organic carbon. If just removing the perchlorates, adding nutrients, and perhaps water-retaining carbon was all that was needed, this might not be too dissimilar to a hydroponic system using the regolith as a substrate. But this is really only part of the story in making fertile soil.

Nitrogen in the form of readily soluble nitrates can be manufactured on Mars chemically, using the 1% of N2 in the atmosphere. It is also possible nitrogen rich minerals on Mars may be found too. Phosphorus is the next most important macronutrient. This requires extraction from the rocks, although it is possible that phosphorus-rich sediments also may be found on Mars.

To generate the organic carbon content in the regolith, the best approach is to grow a cover crop and then use that as the organic carbon source. Fungal and bacterial decomposition, as well as worms, decompose the plants to create humus to build soil. Vermiculture to breed worms is simple given plant waste to feed on, and worm waste makes a very good fertilizer for plants. Already we see that more organisms are going to have to be brought from Earth to ensure that decomposition processes are available. In reality, healthy terrestrial soils have many thousands of different species, ranging in size from bacteria to worms, and ideally, various terrestrial soils would be brought from Earth to determine which would make the best starting cultures to turn the remediated regolith into a soil suitable for growing crops.

Ioannis Kokkinidis indicated that Martian light levels are about the same as a cloudy European day. Optimum growth for many crops needs higher intensity light, as terrestrial experiments have shown that for most plants, increasing the light intensity to Earth levels is one of the most important variables for plant growth. This could be supplied by LED illumination or using reflective surfaces to direct more sunlight into the greenhouse or below-ground agricultural area.

One issue is surface radiation from UV and ionizing radiation. This has usually resulted in suggestions to locate crops below ground, using the surface regolith as a shield. This may not be necessary as a pressurized greenhouse with exposure to the negligible pressure of Mars’ atmosphere, could support considerable mass on its roof to act as a shield. At just 5 lbs/sq.in, a column of water or ice 10 meters thick could be supported. It would be fairly transparent and therefore allow the direct use of sunlight to promote growth, supplemented by another illumination method.

Soil is not a simple system, and terrestrial soils are rich ecosystems of organisms, from bacteria, fungi, and many phyla of small animals, as well as worms. These organisms help stabilize the ecosystem and improve plant productivity. Bacteria release antibiotics and fungi provide the communication and control system to ensure the bacterial balance is maintained and provide important growth coordination compounds to the plants through their roots. The animals feed on the detritus, and the worms also create aeration to ensure that O2 reaches the animals and aerobic fungi and bacteria.

Most high-yield, agricultural production destroys soil structure and its ecosystems. The application of artificial fertilizers, herbicides to kill weeds, and pesticides to kill insect predators, will reduce the soil to a lifeless, mineral, reverting it back to its condition before it became soil. The soil becomes a mechanical support structure, requiring added nutrients to support growth.

Some farmers are trying new ideas, some based on earlier farming methods, to restore the fertility of even poor soils. This requires careful planting schedules, maintenance of cover crops, and even no-tilling techniques that emulate natural systems. Polyculture is an important technique for reducing insect pests. Combined, these techniques can remediate poor soils, eliminate fertilizers and agricultural chemicals, improve farm profitability, and even result in higher net yields than current farm practices. [11]

Without access to industrial production of agricultural chemicals and nutrients, these experimental farming practices will need to be honed until they work on Mars.

Given we have regolith-based soil what sort of crops can be grown? Almost any terrestrial crop as long as the soil conditions, drainage, pH, and illumination can be maintained.

Unlike on Earth where crops are grown where the conditions are already best, on Mars, it might well be that the crops grown will be part of a succession of crops as the soil improves. For example, in arid regions, millet is a good crop to grow with limited water and nutrients as it grows very easily under poor conditions. Ground cover plants to provide carbon and that fix nitrogen might well be a rotation crop to start and maintain the soil amendment. As the soil improves, the grains can be increased to include wheat and maize, as well as barley. With sufficient water, rice could be grown. None of these crops require pollinators, just some air circulation to ensure pollination.

For proteins, legumes and soy can be grown. These will need pollinating, and it might well be worth maintaining a greenhouse that can include bees. Keeping this greenhouse isolated will prevent bees from escaping into the base. As most of our foods require insect pollination, root crops like potatoes, carrots, and turnips, can be grown, as well as leafy greens like lettuce, and cabbage. The pièce de résistance that dirt farming allows is tree crops. A wide variety of fruit and nuts can be grown. Pomegranates are particularly suited to arid conditions. The leaf litter from such deciduous trees will be further input to improve the soil.

So the soil derived from regolith should allow a wider variety of crops to be grown, and with this, the possible variety of cuisine dishes can be supported. Food is an important component of human enjoyment, and the variety will help to keep morale high, as well as provide an outlet for prospective cooks and foodies.

Are there other benefits? As any gardener knows, growing food in the dirt is less time-consuming than hydroponics as the system is more stable, self-correcting, and resilient. This should allow for more time to be spent on other tasks than constantly maintaining a hydroponic system, where a breakdown must be fixed quickly to prevent a loss.

Meat production is beyond the scope of this essay. I doubt it will be of much importance for two main reasons. Meat production is a very inefficient use of energy. It is far better to eat plants directly, rather than convert them to meat and lose most of the captured energy. The second is the difficulty of transporting the initial stocks of animals from Earth. The easiest is to bring the eggs of cold-blooded animals (poikilotherms) and hatch them on Mars. Invertebrates and perhaps fish will be the animals to bring for food. If you can manage to feed rodents like rabbits on the ship, then rabbits would be possible. But sheep, goats, and cows are really out of the question. A million-resident city might best create factory meat from the crops if the needed ingredients can be imported or locally manufactured. My guess is that most Mars settlers will be Vegetarian or Vegan, with the few flexitarians enjoying the occasional fish or shrimp-based meal.

If you have read this far, it should be obvious that dirt farming sustainably, is not simple, nor is it easy or quick. A transport ship carrying settlers to Mars will have to supply food to eat until the first food crops can be grown. That food will likely be some variant of the freeze-dried, packaged food eaten by astronauts. Hopefully, it will taste a lot better. The fastest way to grow food crops will be hydroponics. All the kit and equipment will have to be brought from Earth. With luck, this system will reduce the demand for packaged food and become fairly sustainable, although nutrients will have to be supplied, nitrogen in particular. I don’t see sacks of nitrogen fertilizer being brought down to the surface, but instead, there may be a chemical reactor to extract the nitrogen in the Martian air and either create ammonia or nitrates for the hydroponic system.

But if the intention, as Musk aims, is to make Mars a second home, starting with 1 million residents, the size of the population that is large enough to provide the skills for modern civilization, then food production is going to need to be far more extensive than a hydroponics system in every dome or lava tube. The best way is to grow the soil as discussed above. This will not be quick and may take years before the first amended regolith becomes rich loamy, fertile soil. The sterile conditions on Mars mean that there will be no free ecosystem services. Every life form will have to originate on Earth and be transported to Mars. But life replicates, and this replication is key to success in the long term. There will be a mixture of biodiverse allotments and tracts of large-scale arable farming. Without some new technology to deflect ionizing radiation, the Martian sunlight will probably need to be indirect and directed to the crops protected by mass shields. Every square meter of Martian sunlight will only be able to support ½ a square meter of crops, so there may need to be an industry manufacturing polished metal mirrors to collect the sunlight and redirect it.

Single-cells for artificial food

Although our sensibilities suggest that the Martian settlers will want real food grown from recognizable food crops, this may be a false assumption. In the movie 2001: A Space Odyssey, Kubrick ignored Clarke’s description in his novel of how food was provided and eaten, with the almost humorous showing of liquid foods with flavors served to Heywood Floyd on his trip to the Moon.

Still from the movie 2001: A Space Odyssey. The flight attendant (Penny Brahms) is bringing the flavored, liquid food trays to the passenger and crew.

Because the Moon does not have terrestrial day-night cycles, the food was single-celled and likely grown in vats, then processed to taste like the foods they were substituting for.

Michaels: Anybody hungry?
Floyd: What have we got?
Michaels: You name it.
Floyd: What’s that, chicken?
Michaels: Something like that.
Michaels: Tastes the same anyway.
Halvorsen: Got any ham?
Michaels: Ham, ham, ham..there, that’s it.
Floyd: Looks pretty good
Michaels: They are getting better at it all the time.

Still from the movie 2001: A Space Odyssey. Floyd and the Clavius Base personnel select sandwiches made from processed algae. Above is the conversation Floyd (William Sylvester) has with Halvorsen (Robert Beatty) and Michaels (Sean Sullivan) on the moon bus on his way to TMA1.

This is where food technology is currently taking us.

Single-cell protein has been available since at least the 18th century with edible yeast. Marmite or Vegemite is a savory, yeast-based, food spread that is an acquired taste. Today there is revived interest in various forms of SCP, some of which are commercially available for consumers, such as Quorn made from the micro-fungus, Fusarium venenatum. The advantage of single cells is that the replication rate is so high that the raw output of bacterial cells can be more than doubled daily. The technology, at least on Earth, could literally reduce huge tracts of agricultural land use, especially of meat animals. However, it does require all the inputs that hydroponic systems require, and further processing to turn the cells into palatable foods including simulated meats. Should such single-cell food production become the basic way to ensure adequate calories and food types for settlers, I suspect that real food will be as desirable as it was for Sol Roth and Detective Thorn in Soylent Green.

Still from the movie Soylent Green. Sol Roth (Edward G. Robinson) bites into an apple, stolen by Detective Thorn (Charlton Heston), that he hasn’t tasted in many years since terrestrial farming collapsed.

Physical and Mental Health with Soil

However, even if single-cell bioreactors, food manufacturing, and hydroponics do become the main methods of providing food, that does not mean that creating fertile soils from the regolith is a waste of effort. Surrounded by the ochres of the Martian landscape, the desire to see green and vegetation may be very important for mental health. Soils will be wanted to grow plants to create green spaces, perhaps as lavish as that in Singapore’s Changi Airport. Seeds brought from Earth are a low-mass cargo that can exploit local atoms to create lush landscaping for the interior of a settlement.

Changi Airport, Singapore. A luxurious and restful interior space of tropical plants and trees.

There is a tendency to see life on Mars not just as a blank canvas to start afresh, but also as a sterile world free of diseases and other biological problems associated with Earth. Asimov’s Elijah Bailey stories depicted “germ-free” Spacers as healthier and far longer-lived than Earthmen In their enclosed cities. We now know that our bodies contain more bacterial cells than our mammalian cells. We cannot live well without this microbiome that helps us withstand disease, digest our foods, and even influence our brain development. There is even a suggestion that children that have not been exposed to dirt become more prone to allergies later in life. Studies have shown that most animals have a microbiome with varying numbers of bacterial species. As Mars is sterile, at least as regards a rich terrestrial biosphere, it might well make sense to “terraform” it at least within the settlement cities. Creating soils that will become reservoirs for bacteria, fungi, and a host of other animal species will aid human survival and may become a useful source of biological material for the settlers’ biotechnology.

If Mars is to become a second home for humanity, it will need more people than the villages and small towns that the historical migrants to new lands create. The needed skills to make and repair things are vastly larger than they were less than two centuries ago. Technology is no longer limited to artisans like carpenters, wheelwrights, and blacksmiths, with more complex technology imported from the industrial nations. Now technologies depend on myriad specialty suppliers and capital-intensive factories. Mars will need to replicate much of this in time, which requires a large population with the needed skills. A million people might be a bare minimum, with orders more needed to be largely self-sufficient if the population is to be the backup for a possible future extinction event on Earth. Low-mass, high-value, and difficult-to-manufacture items will continue to be imported, but much else will best be manufactured locally, with a range of techniques that will include advanced additive printing. But some technologies may remain simple, like the age-old fermentation vats and stills. After all, how else will the settlers make beer and liquor for partying on Saturday nights?


Kokkinidis, I (2016) “Agriculture on Other Worlds” https://www.centauri-dreams.org/2016/03/11/agriculture-on-other-worlds/

Kokkinidis, I (2016) “Towards Producing Food in Space: ESA’s MELiSSA and NASA’s VEGGIE”

Kokkinidis, I (2017) “Agricultural Resources Beyond the Earth” https://www.centauri-dreams.org/2017/02/03/agricultural-resources-beyond-the-earth/

Higgins, A (2022) “Laser Thermal Propulsion for Rapid Transit to Mars: Part 1”

Balk, M. (2008) “(Per)chlorate Reduction by the Thermophilic Bacterium Moorella perchloratireducens sp. nov., Isolated from Underground Gas Storage” Applied and Environmental Microbiology, Jan. 2008, p. 403–409 Vol. 74, No. 2

Coates J.D., Achenbach, L.A. (2004) “Microbial Perchlorate Reduction: Rocket-Fueled Metabolism”, Nature Reviews | Microbiology Volume 2 | July 2004 | 569

Hatzinger P.B. &2005) , “Perchlorate Biodegradation
for Water Treatment Biological reactors”, 240A Environmental Science & Technology / June 1, 2005 American Chemical Society

Kasiviswanathan P, Swanner Ed, Halverson LJ, Vijayapalani P (2022) “Farming on Mars: Treatment of basaltic regolith soil and briny water simulants sustains plant growth.” PLoS ONE 17(8): e0272209.

Gilster, P “Spacecoach: Toward a Deep Space Infrastructure“, https://www.centauri-dreams.org/2016/06/28/spacecoach-toward-a-deep-space-infrastructure/

Davila A.F. et all (2013) “Perchlorate on Mars: a chemical hazard and a resource for humans” International Journal of Astrobiology 12 (4): 321–325 (2013)

Monbiot, G. (2022) Regenesis: Feeding the World Without Devouring the Planet Penguin ISBN: 9780143135968

{ 142 comments… add one }
  • charlie January 26, 2023, 15:45

    “If Mars is to become a second home for humanity, it will need more people than the villages and small towns …”
    it needs more than people to make a village – it will need a Hillary Clinton …

    • Alex Tolley January 26, 2023, 21:04

      Since HRC will most likely be pushing up daisies by the time the Martian villages and towns are to be created, does that mean that the whole enterprise is going to be futile? ;-)

      • charlie January 27, 2023, 16:35

        “…does that mean that the whole enterprise is going to be futile?”
        if it (the whole enterprise) means its going be like her, then I’d have to answer : Yes.

    • Jeff Wright January 28, 2023, 20:06

      Rust free wheat…trees to grow with no parasites. Dutch Elm…ironwoods?

      • Alex Tolley January 28, 2023, 21:59

        To keep the base plants disease free, all the plant material will have to be sterilized on Earth before shipping, just as plants shipped to California from certain locations must be. This suggests that to be safe, seeds will have to be the principal imports, backed up with sterilized cuttings.

        The biggest issue for me is that apart from wind pollination of grass crops, most crops we eat need insect pollinators. Will bees need to be included on the base, or will workers have to do the pollination with brushes? When you consider the effort, it may be that SCP is the easier solution.

        How is pollination handled in greenhouses and vertical farms when growing insect-pollinated fruit like strawberries?

        • Ioannis Kokkinidis January 30, 2023, 18:36

          Plant multiplication material is NOT sterilized before shipped because in that case along with the pathogens you also sterilize the plant, which defeats the purpose. What you do is follow generally accepted phytosanitary protocols such as shipping the plant without the ball of soil its rooting system is in or washing it out and then planting in some mineral inert material. Also do actual molecular tests on the plant to see that it does not have any infections including fungi. There are also other system methods to reduce infectants, such as growing potatoes for multiplications in high altitude or windy places to ensure aphids, which would carry viruses, do not have a chance to infect the plant. Making sure that your multiplication material is pathogen free is an entire industry which is why between practices and certification a plant intended for multiplication is way more expensive than a run of the mill plant for your pot.

          As for how pollinators are used in a greenhouse, well there are boxes of bees available for this purpose:

          You can buy them from suppliers. Be aware though, tomatoes can be multiplied parthenocarpically, but those sexually reproduced are way tastier, have seeds and are less succeptible to pathogens

          • Alex Tolley January 30, 2023, 22:50

            What would be the issues of having bees in the Mars colony? Can they survive in the greenhouse atmosphere? Can they be kept out of the living areas and reliably confined to the greenhouses? Can the queen and drones be transported on the belong journey to Mars, or will it require a colony? Like plants, it will be important that the bees are disease free when imported. At least bees can only reproduce with a queen and male drones, so it is unlikely that a new colony will appear where it isn’t wanted.

            • Ioannis Kokkinidis February 1, 2023, 17:46

              Bees have flown in space and the have been able to function decently in microgravity. Otherwise all I can say is that we will uncover what are the issues when we get to Mars

  • Montie January 26, 2023, 17:18

    Indoor vertical farming has shown that no soil is needed to grow crops. No Sun either, and here on Earth over 90% less space and water than traditional farms.

    • Alex Tolley January 26, 2023, 21:01

      Can you elaborate on your “no soil” comment. Are you saying that vertical farms are using hydroponics, or some other approach to anchor the plants and provide nutrients?

      If you want to grow grass crops like wheat, are there any examples of this being achieved in a vertical farm?

      If you want fruit and nut crops, how would you grow trees in a vertical farm? Is there any efficiency to be gained from trees given their height?

      It is my understanding that vertical farms work only for high-value crops to be delivered to local markets. The cost of building and operating vertical farms is very high, precluding most commodity crops. For a Mars colony, unless you can locally manufacture the structures and lighting, is there any advantage of going with the vertical farm approach over a more traditional greenhouse?

      • Mike Serfas January 27, 2023, 11:31

        Though they contradict all common sense, there are remarkable results posted for vertical farms. https://www.pnas.org/doi/10.1073/pnas.2002655117 According to that, wheat can grow 24 hours a day under constant light; they mention hydroponic or aeroponic root systems. Despite this, the capital and electricity costs, competing against farms that I think are now receiving about 40% subsidies, vertical farming isn’t profitable. Once the cost of pressure domes over vast fields is factored in, that changes. :)

        https://www.agrifarming.in/profitable-crops-for-vertical-farming-a-full-guide suggests a height limit of about 30 cm for vertical farm crops. But according to them NASA is the agency that pioneered aeroponics and vertical farms for space exploration in the first place, so I bet they can invent a clever way to stack up apple and almond trees if someone gives them a mission of sufficient duration.

        • Alex Tolley January 27, 2023, 13:01

          In my garden, I have both a lemon tree and a lemon “bush” (ie a very small tree that tops out at 6 feet but has its lower branches just above the ground). I suspect the best way to have fruits and nut trees is to breed/engineer varieties that are small, possibly ground-hugging. That would allow stacking if desired, and certainly easier to harvest by hand or robot. Perhaps just careful pruning is the way to go, for example creating espaliers as was done in Europe when the climate was cooler.

          I don’t foresee redwood trees growing on Mars unless it is terraformed (a very expensive, long-term project), so lumber cut from tree trunks seems very unlikely. However, engineered wood from wood shavings from woody shrubs and small trees may be present. OTOH, maybe realistic lumber, or at least veneers, might be 3-D printed from cellulose and lignin.

          • Brett Bellmore January 27, 2023, 18:41

            Bamboo laminates would be a good option for Mars, if they wanted “wood”.

            • Michael January 29, 2023, 9:27

              There is also hemp to make furniture and building materials.

              • Tampa Red January 30, 2023, 17:50

                Not to mention pharmaceuticals; for export only, of course!

                They could call it Mighty Martian Maroon.

  • Ioannis Kokkinidis January 26, 2023, 20:49

    This is a very good article and I like the references to my essay here from a few years ago. Here are though a few comments, with numbers for reference:

    1. The fundamental purpose of animals in a farming system is to convert food sources that are not palatable to humans into sources that are. It will be a while for cows, pigs and chickens, especially since poultry may even fly on Mars gravity. Have you thought though of rabbits? Small, reproduce quickly, do not take much space. As for squeamishness, well, you relatives in the villages do things that are quite squeamish to urban folks and vice versa. The typical American food model with meat in all three meals a day and even in a few snacks inbetween beyond being atypical and unhealthy is simply unsustainable on Mars because Mars does not have the large ranges that the US has where plant culture is hard to impossible. As recently as the 1950s in Greece meat was something the typical family ate on Sunday at best, assuming that it was not lent. I have always assumed that a Martian diet would look like that.

    2. Hydroponics far predates electronics. Electronics failure will simply means that you will need to put up some alarm clocks to turn on and off the fertigation lines. But yes, it does require more care that plain soil based agriculture

    3. For soil remediation there is a panacea: it is called compost. You can create it quite easily by co-composting biosolids, in other words what comes out of the water treatment plant, with hard plant material such as corn stalk. Leave in a place with good aeration for 45-60 days overturning it a few times. Alternatively what come out in the root bags after you have harvested pleurotus mushrooms, or most mushrooms for that matter, is a soil amendment on its own. No need for fancy bioreactors or reverse osmosis for soils, though osmosis may be necessary for water. After washing out regolith just mix what is out there with soil compost and you have ready to use mineral soil. At your nearest land grant college there is at least one professor which specializes in soil remediation and they have most likely already treated something far more toxic than washed Martian regolith.

    4. Cover crops are for the American/North European growing cycle of planting in the spring and harvesting in fall. As a south European it made no sense in me until I came to this country, nothing can really grow unirrigated in a Mediterranean summer. As for soil organic content, no need for that kind of treatment. In the old world there are fields that have been farmed for some 10,000 years now that are extremely low in organic matter. Plants do grow there, so long they get their nutrients

    5. A small emendation: inside a Martian greenhouse there will be the illumination of North Europe, i.e. North of the Alps. Think something like Amsterdam, not Ierapetra. End result we can plan for a greenhouse than looks like one from Amsterdam as opposed to one from Ierapetra.

    6. In the USSR and its successor states local government (think region to county level) maintains a standard farm where they practice agriculture without any chemical inputs, such as fertilizer, which is then compared with what is grown in actual farms to see how many times the standard farm they can achieve and thus evaluate the farms. Low to no input extensive agriculture also means far higher area is needed plus crop rotations and no crop grown every 3-4 years so as to help the soil recover. Also polyculture like the three sisters of the Americas. Honestly it is a balancing act, what is easier, have fertilizers or have 4-5 times the area under agriculture?

    7. What is grown on earth depends on pedoclimatic, financial and economic factors. It is not so much that soil A is good for crop 1 but not for crop 2 and soil B good for crop 2 but not 1 though there are exceptions, most importantly tobacco which grows best in bad soils and rice that needs flooded soils most other crops can’t grow. It is more like in soil A crop 1 will produce $10/1000 m^2 and crop 2 $8/1000 m^2 while on soil B crop 1 will produce $3/1000 m^2 while crop 2 $4/1000 m^2. A good soil is good for all crops and I would refer you to your state’s soil yield database such as Virginia’s VALUES or North Carolina’s RYE. In Mars where we will need to provide all inputs, it is a different calculation

    8. So far it is not known how much single cell protein is safe to eat for a human or even an animal. SCP has proven too expensive compared to field grown crops for this sort of experiment so far especially since the funding agencies e.g. USDA-NIFA are not funding this kind research. We definitely need someone to fund this kind of research

    Please do not take my comments as a take down, I really enjoyed this article.

    • Alex Tolley January 27, 2023, 13:34

      Thank you for your kind comments.

      Meat is not just to convert unused plant material. That can be done by fungi. Meat historically is a very energy-dense food, great if you are hunting or live where plants are rare, such as the Arctic.

      I don’t envisage Martian crops grown in a Mediterranean climate. The med is too dry in summer. [I also read many years ago that there was evidence that the Ancient Greeks exhausted their soils and had to move their farms, much like early American cotton farmers.] If you have a greenhouse, you can create almost any climate you like. Kew Gardens in London has a set of joined greenhouses that recreate a number of terrestrial biomes, as does, I think, the Eden Project in SW England. More to the point as you note, soil conditions will also determine suitable crops. So poor dry soils will support millet, while flooded soils are needed for rice. Neither crop would grow in the other’s soil.

      SCP (as cultured meat cells rather than bacteria) is already sold in Singapore and is expected to be sold in the US soon. My guess is if there are problems, they will be subtle and not known for years. Similarly, processed yeast cell has been available as Marmite/vegemite since before I was born. Yeast cells are still alive in home-fermented alcohols, so they are safe. IIRC, BP’s SCP from bacterial using methanol as a feedstock was not going to be allowed for human consumption because of the methanol, but not the bacteria. Given our knowledge of the microbiome, I would guess that carefully selected strains of bacterial species will prove safe, especially if the product is processed to ensure that the cells are dead or destroyed. We can always feed new varieties to animals if we are unsure of their safety, even if that defeats the purpose of their use to reduce grazing land and CO2 emissions on Earth.

      What does seem self-evident to me, is that space limitations will force Martian farming of traditional crops to be very intensive – polyculture, multiple harvesting – and likely highly integrated with waste management to recycle nutrients. But I could be surprised if it turns out that cultured cells in bioreactors and then processed to look and taste like traditional foods are possible and utilized on Mars to avoid space and labor used to grow crops. Maybe real foods are grown in pots in living quarters as a speciality treat or gift, as oranges once were in Northern Europe. [Do orangeries still exist now that they can be easily transported in bulk from where they are grown?]

      • charlie January 27, 2023, 20:28

        “I would guess that carefully selected strains of bacterial species will prove safe, especially if the product is processed to ensure that the cells are dead or destroyed. ”

        I am NOT going to (knowingly) increase my daily alotment of specially selected strains of bacterial species; whether cells are dead or destroyed.

      • Ioannis Kokkinidis January 30, 2023, 19:20

        I can accept than a Martian settlement of 10,000 people will not have animals grown for meet, but not a settlement of 1,000,000. I know that I am opening a can of worms here because people have strong opinions about food, but plant food and animal food is not the same. Beyond the low hanging fruit such as Vitamin B12 which cannot come from plant based sources there is the issue that even if their nutrients belong to the same category they are not the same. For example the protein of reference for human nutrition is albumin, which is egg protein. You can get proteins from plants too, but pea protein does not have the same nutritional value as albumin. Veganism is more of a 20th century thing and before the abundance of a variety of nutritional sources that modern trade brings practicing often meant a rather short and unhealthy existence. My philosophy has always been Παν Μετρον Αριστον, in other words Everything in Moderation which is attributed to the (tyrant) Cleobulus of Lindus, one of the Seven Sages of Ancient Greece. Yes, fungi can also break down hard material, yes they can provide some nutrition but a long term balanced diet does require animal sources.

        Plants inside a greenhouse are grown preferably in their optimum environment, at least as much as the general environment allows. Plant A will grow better at something like 15-25 C (degrees Celsius) and will survive without growth say 5 C. However economically it does not make sense to have the heater on permanently at night to keep the plant at 15 C, you will keep it at 5 C and let the temperature rise during the day. Also once it gets to 25 you start opening windows to allow it to cool off and new CO2 to enter. We will not be seeing on a Mars greenhouse 40 C in the summer and 40% humidity, sure an olive tree can survive that but it is not its optimum and is not very productive under these conditions. Also it is cheaper to heat a greenhouse from the 0 C which is the maximum Mars gets in its equator to 20 C rather than 40 C.

        My comment about feeding animals SCP has to do with that usually we first test new food on animals before the give to humans. Someone needs to fund studies where animals are fed SCP as a high proportion of their diet before advocating that people eat SCP as a high proportion of their diet. There was a study in late December 2022 that made the news where Dutch researchers analyzed all vegan sausages in the Dutch market, I no longer remember if they also fed them to animals or people. With the exception of tempeh based sausages, the metals in their content, meaning Fe and Zn if I remember correctly, were not bioavailable because they became bonded to phytase. Tempeh did not have that problem because the phytase had been reduced though the fermentation that created tempeh. I do eat the meat substitutes available in Fresno when it is Lent, we are not there in taste compared to what they are substituting and nutrition wise also we are not there.

        It is pretty well known among soil scientists that with the exception of river valleys all ancient soils have been exhausted to eroded due to millennia of agriculture. We did go up Mt Parnitha when on a field trip as an undergrad and we were shown a soil formation that can only form under a meter of soils that was exposed to the surface because of erosion after 6 millennia of agriculture. We were also shown pictures from Spain and Portugal where after three centuries of intensive agriculture the field had been reduced to an O-R horizon so they abandoned agriculture and took up silviculture because it was impossible to grow row crops any more. This, along with phytosanitary reasons (when you grow in the same greenhouse the same crop constantly pests get out of control) is why hydroponics was adopted in the 1960s in large scale staring in the Netherlands.

        • Alex Tolley January 30, 2023, 22:44

          (…)a long term balanced diet does require animal sources.

          I thought that was a myth. I know very healthy adult vegans. One definitely doesn’t was to make a developing child vegan, but once adult, that is no longer an issue. It may require some extra vitamins like B12, but AFAIK veganism is not a health problem.

          My comment about feeding animals SCP has to do with that usually we first test new food on animals before the give to humans. Someone needs to fund studies where animals are fed SCP as a high proportion of their diet before advocating that people eat SCP as a high proportion of their diet.

          In principle, I would agree with you. However, other new foods are introduced without animal testing. However, it reminds me of the attempts for Britain to find alternative food sources during WWII when German U-boats were making food imports very difficult. Marine zooplankton was harvested with an innovative net. The cooked zooplankton was fed to rats in increasing fractions of their regular chow. Apparently, once the ratio got to around 30%, the indigestible chitin exoskeletons clogged up the rats’ intestines. That was definitely a case of animal testing being needed before the food was foisted on the general public.

          • Ioannis Kokkinidis February 1, 2023, 18:02

            Last time I was in Mt Athos in the summer of 2022 I was told the story of a monk who during the German occupation, that would be WWII, developed tuberculosis and was told by the doctors to start drinking milk. He left for Ouranoupolis where he started consuming dairy- the diet of Orthodox monks is vegan to pescatorian, and did get better. I am pretty sure that you know many healthy vegans, especially today that we know what constitute a healthy diet molecularly, what are the necessary elements you need to get and there is a global supply chain to provide them for various sources. Also note we live in relatively fair weather conditions in terms of health, COVID 19 is the first pandemic in a century as opposed to the early modern period where there was a plague epidemic once a decade between the black death and the 18th century. Every new environment people live in brings about new discoveries that we did not know off. For example that human shed so many skin cell constantly was not known until it was discovered in the closed environments of submarines. Also much as evolution is not static and does not have an end point, it is certain that modern innovations often run into unexpected demands from our bodies. The sedentary office life is comfortable, but our body does need to exercise which is a why you are healthier if you go to the gym regularly. I am fully aware how the genes that allow adults to process dairy are associated with people of origins where diary animals were domesticated and just how many lactose intolerant people are out there. This is why I am willing to err on the conservative side, let’s try to eat everything people on earth eat than remove something and try to see if it is really necessary. There will be Martians that will want to eat meat and not just the easier to grow mealworms and snails just as there are many Norwegian Americans that want to eat lutefisk for cultural reasons, even though the description I have is that it is barely palatable to American palates.

  • Joe January 26, 2023, 20:55

    Future Martians will need to make sure that are getting enough protein, for example, rice and beans which eaten together give you a complete protein source.
    Lettuce and alot of other vegetables provide variety and vitamins , but are largely water and cellulose.
    A non animal protein, similar to yeast, is a naturally occurring fungus called fusarium venenatum (commercially known as Quorn)…
    And dont forget the wide range of mushrooms which dont require light to grow.

    However, consideration should probably be given to bringing chickens.
    1) they produce eggs, which provides a periodic repeatable source of high quality protein, instead of a one time butchering like pigs, cows, rabbits, etc.
    2) they’re fairly compact
    3) even in low light levels of winter some breeds continue to lay
    4) they’re great at recycling scraps
    5) theyll eat stuff you may find distasteful like meal worms, crickets, etc.
    6) their waste provides a high quality manure for crops

    It appears that there are large expanses of permafrost on mars. Liquifying that water would potentially provide a habitat for any number of seafood, including cold water tolerant fish. I cant help but be reminded of the ocean life living under the ice caps.

    Regarding light sources, I think Id feel safer with reflective surfaces concentrating the light. They’re lower tech, unlikely to fail, and probably far easier to manufacture on site than LEDs.

    • Michael January 27, 2023, 8:58

      “Regarding light sources, I think Id feel safer with reflective surfaces concentrating the light. They’re lower tech, unlikely to fail, and probably far easier to manufacture on site than LEDs.”

      The only issue would be dust storms sticking dust to the reflectors but there should be ways to clean them automatically. As for LED’s they could be used to boost needed frequencies of received light. Fungi offer a good source of proteins and can grow in cold weather.


      And can be used to make clothing.

      The material is made in a process called bio-fabrication which means it’s grown in a lab. Fungi root system, called mycelium, is being harvested for the process. The result is a leather-like material that can be used for both clothes and furniture’s.

      • Alex Tolley January 27, 2023, 12:17

        See my comment lower down regarding reflectors. I think we are in broad agreement.

        Fungi will likely be an important part of the soil production process, although mushrooms may be a specialized part of the food crop. As for using their structures for clothing manufacture, that is possible. IDK of any fungal fabrics on the market currently – it is mostly research material AFAIK. Plant fibers are far more established, and bamboo can be used for a range of manufactures from cloth to flooring. Gene-engineered organisms can be used to make synthetic silk, and I wouldn’t rule out synthetic fibers either. Weaving machines are lo-tech so any process that can make long fibers that can be spun into thread and woven could be present on Mars. Given the likely shortage of goods, I would expect the need to display individuality may be expressed in clothes, fabric colors, and designs. What I don’t expect is cotton growing, or sheep rearing for wool. Without large animals like cows, there will not be leather, although leather substitutes may be available.

        What we should be wary of is visualizing Martian settlers as in any way similar to those in North America, especially the American West. If anything, it may be more like the more dense populations of India, North Africa, Indonesia, and China, but with much of the architecture below the surface, yet still crowded, with food smells and a distinct “Martian” culture developing to meet the needs of that environment. Independent miners and farmers seem unlikely in such a harsh environment that will need lots of help from others to survive.

    • Alex Tolley January 27, 2023, 12:36

      The technology we live with and available to the settlers might be as much of a handicap as a benefit. I often think that more primitive technologies might be better for survival, simply because they can be repaired with simpler methods and therefore less reliant on manufactured imports. farmers in the 1940s US that seem to be what Heinlein envisaged as colonists, might be a better bet than modern agronomists requiring electronics and computers. No-one is farming outside on the surface, it will all be inside. It is possible farming with not happen at all, with food being produced from cell growth and processed to mimic foods we eat, or perhaps more like the biscuits in “Soylent Green”. Would we even bury the dead, rather than recycle them? My post is about options and considers other issues beyond foods as nutrients.

      Clever and inventive use of local resources will be an important skill on Mars, much as it is in any relatively isolated settlement. Unlike earth, there is no indigenous macroscopic life to exploit, just a mostly sterile, rocky surface, and whatever can be cultivated from seeds and eggs. Wood, for example, would be the rarest of materials, and therefore an extravagant luxury import, even after a generation when some trees have reached maturity to harvest.

      While I would want to visit the Moon and, given time, Mars, I wouldn’t want to live there. Mars will be a harsh place to live, and very limited and constraining, despite the apparent unexplored surface.

      • David Claughton February 3, 2023, 20:43

        “Would we even bury the dead, rather than recycle them?”

        While recycling of bodily waste and, in fact, pretty much everything else is likely to be an essential part of a functioning Mars colony, I still have doubts that loading dead bodies into a recycling plant is likely to be considered acceptable.

        Mind you, strictly speaking burial *is* a form of recycling. While cemeteries are not usually considered suitable places to grow crops, most do have trees and gardens, which presumably benefit from extra nutrients provided by the inhabitants…

        On Mars, I’d imagine cremation is likely to be considered both acceptable and efficient, with the ashes scattered on green places – a practice common enough here on Earth.

        • Alex Tolley February 4, 2023, 13:53

          Soil from cemeteries is particularly fertile. Very useful where the soils can be poor.

          I agree that Martians will not likely want their bodies tipped into a recycler. OTOH, the culture may differ. Think of the fictional Fremen recycling to extract the water from the dead in Dune.

          There are/were different burial methods on Earth, and a new one is eco-burial to prevent the use of fossil fuel-powered cremation. If carbon fixation on Mars is easy, then cremation may be the method of choice. OTOH, if soil manufacture is hard, then maybe burial in special soil-making pits might be preferred. I suspect it will all depend on culture and resources as to the method[s].

    • Robin Datta January 27, 2023, 16:48

      Reflective surfaces will need the equivalent of feather dusters and/or pressure hoses to periodically clean off accumulated dust.

  • Ben January 26, 2023, 22:33

    I think chickens would be a useful farm animal on Mars for a few reasons
    – they turn insects and scraps into eggs
    – their droppings are useful fertilizer
    – in the low gravity of Mars, they could fly, which I think they would enjoy
    Also, I would say that artificial fertilizers will be heavily used in the early days at least. It’s a well-understood technique and Mars will need a mature chemical industry anyway.

    • Michael January 27, 2023, 11:36

      They like too scratch the ground up so would help mix up the soil and birds can live in lower pressure enclosures than humans due to their higher efficiency lungs.

    • Alex Tolley January 27, 2023, 11:55

      Chickens, like other animals, will need to be managed on the months-long journey from Earth. Even starting with fertilized eggs most of the journey will require managing adult birds. As for food, I do not envisage insects as being freely available in the Martian base. Any escapees from food-producing areas will likely be eradicated as fast as possible. They certainly won’t want pests, especially cockroaches. If chickens are present, settlers may have to be vetted for allergies to chicken feathers, as there is no escape from the allergens.

      If Mars is to use fertilizers, it will need the infrastructure to support production, especially of nitrates. Yet more mass to transport, and initially bringing sacks of fertilizer on the ship seems unlikely to me. Better to avoid such fertilizer as much as possible, IMO.

      • Michael January 28, 2023, 7:04

        It takes around 21 days for the egg to chick cycle, we could send the eggs on an express rocket after all there is no big infrastructure need for their journey upkeep. They could be housed in a lava tube setup with part LED lighting with lower pressure enclosure requirements which substantially reduces the building structures.

        • Alex Tolley January 28, 2023, 13:30

          It takes around 21 days for the egg to chick cycle, we could send the eggs on an express rocket (…)

          What “express rocket are you speaking of? You seem to imply that there is one in the wings that can do the Mars run in less than 21 days. I know of no such ship, although the “Wind Rider” can be inferred to have that sort of mission time. If we can get such short delivery times to Mars, a lot of opportunities open up.

          • Michael January 28, 2023, 17:09

            The payload would be quite small and if attached to a very powerful rocket it could get to mars quite quickly, 21 days is rather fast though. But there are other birds with longer incubation periods of up 80 days such as the albatross and ostriches at around 50 days.

            • Alex Tolley January 28, 2023, 21:52

              It would be terrible if on arrival, the eggs were all broken and all that was left was a lot of dead chicks just prior to hatching. The developing chick embryos still need life support as the egg shells require gas exchange. Unless O2 is provided, and waste CO2 vented, the embryos will suffocate. I don’t raise chickens, but don’t the eggs need turning in the hatcheries? Is gravity important for embryo development?

              • Michael January 29, 2023, 11:21

                Perhaps spin stabilisation of the craft to provide a small amount of g forces. Eggs do not require a lot of air and upkeep and we could quite easily do some experiments on earth.

      • Ivan Vuletich January 28, 2023, 23:55


        Don’t count goats out. They used to be common on sailing ships. Can eat anything and adapts well to life at sea. One goat apparently sailed around the world with Captain Cook. If any animal can survive a trip to Mars a goat can.

        Slow cooked old goat curry anyone? Special dish served every First Landing Day

        • Michael January 29, 2023, 9:31

          Saved but for the smell of these lovely creatures.

          • Ivan Vuletich January 29, 2023, 17:45

            That might be part of the social or justice system.
            Drunk & disorderly? 30 days mucking out the goat pens after your regular work shift. Teenagers need to spend a year helping on the farms including the goat pens.

  • Michael Fidler January 26, 2023, 22:38

    Martian lava tubes could be a good place to grow crops with a mirror system to send concentrated sunlight down through them. The amount of water on Mars in ice beneath the surface could be used to create lakes in these 3000 to 10,000 foot diameter lava tubes on Mars. Could the soil underground be better then surface soil?

    • Alex Tolley January 27, 2023, 11:45

      I favor reflective surfaces over light modules for the manufacturing issue. However, reflective plates, whether glass or metal will be both covered in dust and need regular cleaning and abraded reducing their reflectivity. Extended dust storms reducing light levels cannot be avoided by this method. Pragmatic settlers may use both mirrors and lighting. Surface greenhouses don’t need lighting when the sky is clear when sited near the equator, as light levels are similar to those in Northern Europe. But the trade off is increased radiation exposure, not just for the crops, but any human worker in the green house.

      Lava tube living solves the radiation issue, but then lighting must be provided by reflectors through ports, and interior lighting. Without views, living underground can be oppressive. Martian settlers might complain that they have come millions of miles to live in a new home with “room to breathe” but are stuck in a dark tube. In any case, the limited number of tubes means that the growing population will either need surface structures or create subsurface living and working areas. Jablokov’s “River of Dust” novel depicts a Martian civilization that has built underground cities. I don’t recall the novel explaining how food is grown. The same food supply issue is found in McDonald’s “Luna” trilogy, where the lunar cities are underground, but there seems to be no mention of any ag areas. Food production must be entirely synthesized from unicellular organisms. Real coffee is extremely expensive and imported. Most lunarians drink mint tea.

      As for the soil issue, I have no idea. The regolith, if any of the tube floors, should be almost perchlorate free. However, the inside of the tubes may be just solid rock, and possibly very hard rock. Without exposure to impactors and day/night fracturing, ,there will not be any regolith to collect as the basis for soil production. This doesn’t stop settlers from bringing regolith into the tubes, but then it will be contaminated with perchlorates.

      • Michael Fidler January 27, 2023, 19:44

        Easy way to get around the dust problems is put the mirrors in orbit. 2 mile across lava tubes 100 miles long with 1000 feet deep lakes. Dust stormd effect everyone no matter where they are at
        except below ground.

        • Alex Tolley January 27, 2023, 21:17

          Even orbiting mirrors cannot push sunlight through the dust storms. A storm weeks long will keep the surface quite dark for during this time. As long as the storm doesn’t last months, the plants may be fine as long as they are not cooled. However, if they are integral to ECLSS O2 production, that could be an issue.

          KSR’s Mars trilogy had solettas in orbit to help with the terraforming project. Orbiting mirrors have been proposed to illuminate cities at night, but how do you position them to illuminate the daytime? [This is different from ground-based mirrors.] Is the solution to reverse the day/night cycle for the ag areas?

          • Michael Fidler January 28, 2023, 6:47

            Looks like another problem with surface based crop production;
            Influence of Martian Radiation-like Conditions on the Growth of Secale cereale and Lepidium sativum.

            The Fact and Fiction of Martian Dust Storms.
            “Once every three Mars years (about 5 ½ Earth years), on average, normal storms grow into planet-encircling dust storms, and we usually call those ‘global dust storms’ to distinguish them,”

            The dust storms will not damage ground bases mirrors according to the article, they just need to be cleaned off or covered during the storm.

            As for living in an environment on the surface a giant lava cave would be able to develop a complete close ecosystem of plants, fish, shellfish, worms etc… that we do now on earth based aquamarine systems or Aquaculture ponds. https://www.examplesof.net/2018/09/10-examples-of-artificial-man-made-ecosystem.html

            Large ground based metal mirror systems do not need the accuracy of telescope mirrors and multiple concentrators of sunlight could be routed above the ground near the roof of the cave for miles and directed down to illuminate below. Gravity on Mars is only 38 percent of earth so infrastructure projects would be much easier to build. The Martian surface has a large number if nickel/iron meteorites on its surface plus many more asteroids coming nearby from the asteroid belt. Surface based and space based production of raw materials with 3D Printing Machines producing metal products.

            Plenty of ice…

            • Alex Tolley January 28, 2023, 13:41

              Elsewhere I have suggested that ice would make both a good, but light transparent, radiation shield and a suitable mass to relieve the pressure on the surface greenhouses from blowing out.

              Elsewhere I have discussed the issue of radiation in unprotected ag areas in surface greenhouses. [OGH, PG, has suggested that this article will be posted on CD.]

              Good to hear that dust storms will not abrade surface mirrors, although I await actual experience to confirm that. Surface mirrors will be a lot easier to manufacture and reorient with the sun to maintain the light tunnel being illuminated. But again, they will not be useful during these global dust storms, and as Ioannis has indicated, Martian illumination levels around the equator are not that different from those experienced in greenhouses in Holland.

              As Robin has suggested that a feather duster could be used to clean the mirrors, I will try StableDiffusion to paint an image of a robot dusting a mirror on Mars.

      • Mike Serfas January 28, 2023, 12:59

        According to https://www.researchgate.net/publication/328319061 the hardness of Martian dust is only Mohs 4.3, so I think you shouldn’t even need special glass to avoid abrasion. So far as I know the problem with Mars rovers is simply that there is no one to wipe the panels off. I don’t understand why NASA hasn’t worked out a solution, whether it be something as simple as a windshield wiper or electrostatics, or some new technology. Given recent impressive advances in acoustic holography ( https://www.science.org/doi/10.1126/sciadv.abn7614 ) … I wonder if engineers could place an array of acoustic transmitters on solar panels or reflectors so that the main force of the entire array can be focused to raster scan the entire surface, systematically cleaning away the dust without macroscopic moving parts.

        There was a paper saying that supplementary wind power can help to cover gaps in solar availability. https://www.nature.com/articles/s41550-022-01851-4 It will also be interesting to see if some recent suggestions of ongoing geologic activity can lead to sites where geothermal (nay, areothermal!) energy is an efficient option.

  • Tampa Red January 26, 2023, 23:31

    In order to grow things on other worlds, we’ll have to live there for a long time just to learn how.

    But we’ll not ne able to live there for any length of time unless we have an established agricultural technology and lots of experience under those conditions.

    • Alex Tolley January 27, 2023, 11:25

      There is a chicken and egg issue, I agree. In practice, I think prepackaged food supplies will be the mechanism to feed the settlers until local food production is working. At this time, the favored method is hydroponics, as Ioannis deftly explained in his article and much of the Mars Underground work seems to suggest. But there is the issue of expansion, and this is where other approaches may be used and which I highlight in the OP.

      • Henry Cordova January 27, 2023, 14:03

        The point is, do we need to go through all this trouble? Sure, it may be good for survey crew morale to have the occasional fresh salad with their frozen food concentrates, but there is really no need to have a permanent base there requiring a full-fledged agricultural establishment and the enormous investment, research and support that would require. Even here on earth, with our advanced agricultural science and millennia of accumulated experience, crops still fail and farmers still go broke. Too many things can go wrong for us to bet the lives of a survey team on the success of a farm where we never had one before.

        I can see the potential need for a semi-permanent scientific base on Mars, like we have in Antarctica, but these attempts to colonize another world are a waste of time and effort. We already have a viable planet with plentiful under-utilized stretches, like the ocean basins and the polar regions and vast expanses of desert. We have the capability to settle these places now, although I doubt we could do so in away that produced more resources than it consumed. If you have to make your own air and water and chemically stabilize the soil so it isn’t poisonous, it becomes a fantasy, not a future. Even on our own remote terrestrial artificial habitats, like military bases, offshore rigs, mines in remote places, or scientific observatories, we have to bring in almost everything we need to survive by sea and air.

        We live on a perfectly hospitable planet, one which is much more productive than any environment we could hastily devise in vacuum. If we should pollute the earth so badly we were forced to leave it, we would not have sufficient earth-generated resources to build and maintain space settlements until they became self supporting. And if they should ever become necessary, for whatever reason, putting them at the bottom of a gravity well makes no sense.

        The space groupie colonization fantasy is like the sci-fi terraforming fantasy. Its not impossible, it is just unnecessary .

        • Alex Tolley January 28, 2023, 15:13

          If our population is confined to Earth, then there will be fairly finite limits to economic growth, limits that we will reach fairly quickly even would all the necessary changes to avoid a climate and biosphere catastrophe.

          What that means is that human expansion into the galaxy is effectively “off the table”.

          Mars is certainly not the best 2nd home for humans. If we could build large O’Neill space habitats, that may be a better solution, even if each habitat has a hull surface area no greater than islands, and certainly not content or world sized. Building the habitats with multiple interior levels like the fictional “Babylon 5” makes more sense, and technology can create substitutes for views of the interior, like the Venice Casino in Las Vegas. Alternatively, robots could be the spacefaring economic entities to expand the terrestrial economy, but then wouldn’t they be the best colonists in the galaxy for the same reasons as humans not colonizing Mars?

          It seems to me that traditional SETI almost assumes your position, with ETI limited to its home world, certainly not beyond its home system, and using em communication to reach other ETIs. KSR’s “Aurora” novel seems to be sympatico with the futility of living on even apparently suitable exoplanets, and that even an ecologically enclosed starship has a finite life span as the systems slowly degrade over time, implying space colonies are not the long-term solution either. All rather depressing for space cadets, especially poignant if it turns our life is rare and mind even rarer. As the conversation between Ellie Arroway and her father about ETI in “Contact” (movie version):

          Young Ellie: Dad, do you think there’s people on other planets?
          Ted Arroway: I don’t know, Sparks. But I guess I’d say if it is just us… seems like an awful waste of space.”

          • Henry Cordova January 28, 2023, 19:40

            I’m certainly not opposed to the exploration of space or the expansion of our species; on the contrary, I support it and am willing to work for it. I just don’t think it will ever provide a home for our population in the event our planet is overcrowded, hopelessly polluted or threatened. I agree space may teach us much we may need to know, but no one is going to live “out there” except a tiny minority supported by the work and resources of the vast majority of those left behind. No “huddled masses yearning to breath free”, just a bunch of pampered technocrats who can afford the price of a ticket. A highly subsidized ticket, I might add.

            That is an fundamentally elitist program, and I am opposed to it.

            • Abelard Lindsey January 30, 2023, 1:05

              The problems of both industrial pollution as well as overpopulation have been largely solved without having gone to space. The purpose of going to space is not to flee a messed up Earth. Rather it is to have a frontier where any self-interested groups can go out on their own and have autonomy from political systems they do not share.

              • Henry Cordova January 30, 2023, 14:10

                What concerns me is that space might become a place where toxic and malignant philosophies can go and fester, to nurture and perfect their social pathologies so they can force them on the rest of us.

                Our own history of colonization here on earth is rarely about noble pioneers fleeing the oppression of the Metropole; its mostly about social misfits, predators and opportunists seeking the “freedom” to inflict their tyranny on others with total impunity, either the the wildlife, the natives, or their fellow colonists. My vision of the frontier isn’t hardy homesteaders, noble sodbusters and quaint churches, its ruthless cattle barons, greedy miners and endless water wars.

                As for ” industrial pollution as well as overpopulation [being] largely solved “, well, I’ll not even bother to comment, let others make up their mind for themselves about that.. We may have the technical knowledge to address these problems, but those eager to cavalierly dismiss them
                (or cheerfully export them to other worlds) are interested in no one’s political autonomy but their own.

                Its no accident that techno-boosterism, entrepreneurial fantasies and authoritarian politics are so highly correlated.

                I do agree that off-planet communities will lead to cultural diversity in the human species, something that seems to be quickly eroding on our crowded home world. But when its phrased in those terms, it may not seem quite as appealing.

                • Alex Tolley January 30, 2023, 16:44

                  This blogger seems to reflect your thoughts.
                  Against Mars: Space Colonization and its Discontents

                  Commenters on FB’s Mars Society group seem overly optimistic about the ease of Mars colonization. I partly blame Zubrin for this.
                  Enthusiasm is good, but there seems to me little realism about the difficulties, and an almost tech bro naivety about how humans behave. While I would expect that the mortality rate will be a lot lower than that experienced by the many that made the wagon treks across the North American continent to start farms, I don’t expect human nature will change that much to prevent the many social pathologies that were common in the absence of effective law enforcement. The US has only just made lynchings a crime, so it wouldn’t surprise me if Heinleinian summary judgments were made and executed by chucking unsuited people out of the airlock, as just one example.

                  • Mike Serfas February 1, 2023, 21:03

                    Saadia is right so far as he goes. A Mars colony must be a technological achievement, and in our society technology is defined as what gives an elite who control it power over the commoners who do not.

                    Yet there is a larger context. If backward ideas might fester on Mars, they also fester on Earth. If technology destroys freedom on Mars, what can we say of each week’s news here, where science consists mostly of wearable sensors and trackable devices and enhanced AI threat analyses and every manner of surveillance?

                    If humanity does not belong on Mars, it also does not belong on Earth. The great powers play odds with nuclear war, and the people of the world ignore them, because they don’t know if that is the worst that could happen. Not when so many bright minds work on brain-machine interfaces and automated suppression of opinion.

                    Mars represents an escape – if not from Earth, then from thought, about the sad realities of humanity. A few outposts would pose little real risk of surviving to spread slavery to the stars. Perhaps they will discover something amazing. Perhaps one day the Fravashi will discover their ruins and run simulations of how the human race went wrong, such as the one we live in now.

                • charlie January 31, 2023, 19:21

                  “What concerns me is that space might become a place where toxic and malignant philosophies can go and fester, to nurture and perfect their social pathologies so they can force them on the rest of us.”
                  Thats not alays true; thats just propaganda that people drill into others for political purposes.

                  • Henry Cordova February 1, 2023, 1:29


  • Mike Serfas January 26, 2023, 23:33

    A Martian base should have some farm animals for sake of the ecosystem as well as practical uses. Parts of any farmed plant are inedible to humans, and that biomass needs to be recycled quickly into fertilizer. A very expensive mission with limited spaces for humans will not have room for cows soon, but there are other options; for example guinea pigs are widely farmed for meat in cramped environs, and could also be used in research or as pets.

    • Alex Tolley January 27, 2023, 11:21

      The problem with farm animals is getting them to Mars. A trip of months, probably in micro-g will require careful management, not to mention food and oxygen. Large animals like cows seem highly unlikely. Rabbits a better chance.

      Elsewhere a commenter stated that the Ancient Romans were able to ship large animals from Africa to Rome, so why not Mars. However, the trip time from Egypt to Rome by sea is far less than a trip to Mars, and the air is free. They also didn’t need to stay out of reach of land for feeding, except for the short hop from Tunisia to Scicilly, requiring only a couple of days to make that leg before they were in reach of places to load food. None of this is possible for the Mars trip as it stands, even with the fastest propulsion systems proposed.

      On top of this, any crop failure results in having to cull your animals to try to feed the settlers. One doesn’t want to do this with a heavier animal like a cow or even a goat brought for milk.

      So small mammals, fish, and invertebrates seem like the best bet. Going Vegan/Vegetarian might be the best option for Mars settlers.

      • Mike Serfas January 27, 2023, 17:20

        Someone posted a link to Biosphere 2 here recently (I never knew that was where Steve Bannon began practicing politics…), and from a quick review of the history it seemed that the social breakdown in the experiment began with their enforced “healthy” diet. For humans to thrive away from Earth, it seems best to plan for substantial indulgences. Not a *cow* sized indulgence, but chickens and rabbits and guinea pigs at least. Those would be especially helpful if you can genetically engineer the guinea pigs to “sunlight sneeze” or otherwise visibly alert colonists any time they are exposed to ionizing radiation or their cells detect DNA damage.

        • Alex Tolley January 27, 2023, 21:08

          As Ioannis notes, once we change our lifestyle from country living to cities, we get rather squeamish about killing animals. We buy our meat in neat packages. Being exposed to what goes on in abattoirs is so shocking that many have banned taking images and videos of their operations. While my mother told me she wrung the necks of chickens when she grew up in a village for a while, I would have a lot of trouble doing so. It might be enough to make me vegetarian. Would a Mars settlement need a butcher to handle this, rather than the settlers taking turns in the ag areas and animal slaughter being one of the tasks?

          [I knew Bannon was involved with Biosphere II, but not about his influence on the lifestyle and diet of the volunteers.]

          • Mike Serfas January 28, 2023, 12:20

            I should clarify that Bannon wasn’t involved at the very beginning, so as far as I know he isn’t to blame for the original diet plan.

            My gut feeling is that settlers can’t all be squeamish. Also, we would do well to have an international mix of settlers, and among these the genetic advantages of sub-Saharan African colonists are particularly hard to ignore. There are many short-statured people there, some at risk of persecution in their home countries, whose reduced architectural and nutritional requirements would do much to make ends meet – and, they are not alienated from agriculture. Mostly we need their diversity to help find people who don’t lose bone and muscle mass in low gravity, nor suffer motion sickness in space, nor vomit when trying to burp in low gravity, and maintain healthy blood pressure throughout the body, and such. If humans do take to space, within 20 generations we will start to think of the new adapted population as a species, let’s say Homo apotelesmatis. Throughout the history of our genus new human species have primarily originated from Africa due to the range of genetic variation available there for natural selection to select from.

            If we are looking for a colony to succeed on Mars long term, it might pay to think at least as much about how the arrangement of the settlement will fit with Twa or Mbuti culture as how it will fit with urban US culture.

  • Robin Datta January 27, 2023, 4:11

    Something along such lines was tried here:

    Biosphere 2

    The Soviets also tried similar experiments:

    Soviet Biosphere experiments

    • Alex Tolley January 27, 2023, 10:49

      Biosphere II was trying to demonstrate something very different. As far as the 7 bionauts were concerned, it proved a constant battle to keep the CO2 levels from climbing too high and they were always hungry, unable to grow enough food.
      IDK anything about BIOS-3 other than it seemed closer to an ECLSS that one might expect for a Mars colony or deep space ship.

      I would expect a Mars colony to be more engineered, using more chemical and physical life support controls. For example, O2 could be supplemented by water electrolysis and the extraction of regolith perchlorates. CO2 would be controlled by reusable scrubbers as well as photosynthetic fixation.

      O’Neill was quite brute force about controlling problems in the ag areas of his space colonies – he proposed to expose them to vacuum and extreme heat, and start afresh.

      • Duckie January 28, 2023, 0:00

        A great article and lots of great comments!

        I believe that both Biosphere 2, and Bios3 made, and are continuing to make great strides in their research. However, I have studied hydroponics, and quickly abandoned it for it’s cousin Aquaponics.

        1) Hydroponics is dependent on the industrial manufacturing infrastructure to produce the chemical nutrients, 2) water can only be used through 1-3 crop cycles before it becomes saturated with salts making it poisonous to the crops. 3)

        1) Aquaponics is dependent on the fish waste for its nutrient base, and 2) the plants suck up those nutrients cleaning the water, and 3) water cycles such that if evaporation is kept to a minimum systems can reuse the water for years at a time, requiring only occasional top-offs.

        By combining a vertical component of horizontal tubes (supporting leafy crops) with a modified media bed (flood and drain) supporting root, and fruit crops, a wider variety of foods can be produced. Add a small chicken coop between the pond and the media bed, where pond water flows under the chicken’s feet to wash the wastes into the garden, and increase the fertilizer and reduce efforts.

        A friend has been successful at growing dwarf fruit trees, and bananas — to the point of giving away banana pups to friends. You are correct that vertical farms cannot support tree crops, especially not hydroponics.

        And as for construction materials – consider bamboo (it grows really fast – though cures slowly), and mycellium can be grown into brick shapes – or stools, chairs, even dishes.

        Finally, an important note. SCP, as one commenter mentioned can cause issues in the human digestive system if consumed in quantities. That being said, Cyanobacteria such as spirulina and chlorella are voracious consumers of carbon dioxide, releasing oxygen via photosynthesis – if their culture media were fed from the fish pond/chicken coop – these SC creatures have the potential to produce oxygen at rates trees cannot match in enclosed environments.

        In a much more compact space ( I have a system inside my RV – running well for several years) a system could be initialized on board ship, and with the species identified above, and their bacterial, fungi, and insect helpers could be grown slowly to reach maturity about the time they arrive at Mars. OR could be accelerated to provide a small portion of food while on the journey.

        • Alex Tolley January 28, 2023, 13:51

          IIRC, the earth Island Institute on Canada’s Prince Edward Island was involved in such integrated systems, so that they could produce fruit and veg in greenhouses, and the hydroponic water was run into Tilapia fishponds and then cleaned over bacterial-coated bivalve shells to be recycled back into the hydroponics system. This was back in the 1970s/80s and I think I read about this in an issue of Stewart Brand’s Co-Evolution Quarterly. At one point I was thinking about building a small hydroponics system in my California backyard to grow strawberries, but in practice, it was a bust. It needed to be done properly with more than a simple kit, and daily maintenance was required. [I am not a gardener and really need low maintenance gardens. Even a little weeding is annoying.]

          Do you have any good references/website URLs that you can post to support your comments on crops and performance, as well as “how to’s” for the system you put into your RV?

          • Duckie January 29, 2023, 0:30

            The research on IIRC is interesting, but I wasn’t able to bring anything up referring to the project. Though I did do a few searches on bivalves. I am intrigued with the idea of including bivalves – particularly for reduction of fish waste solids. It sounds like the bivalves could remediate these.

            Sorry to hear about your strawberry bust. So far, I haven’t been able to get strawberries to do well myself.

            A good discussion comparing Hydroponics vs Aquaponics:


            I did not find my friend’s link, but here are two others that discuss growing bananas in Aquaponics:


            And here are a couple links about Bamboo in Hydroponics:

            As for mycelium as construction material:
            Check out this google search: mycelium bricks art tower.

            When I started EarthSeed, Inc, my specific goal was to develop a biological life support system for Starship, the Moon, and Mars. My RV is the culmination of over 15 years research. My system currently is housed in an 8′ x 14′ room with a ceiling height of 6′. The 250 gal pond and composting toilet are on one side, the garden on the other. And bridging the back wall will be the chicken coop with 2-3 laying hens.

            I have an automated feeder for the fish, feeding them 2x daily; the pump runs every hour for 15 minutes pushing water to the garden, and the lights operate from 9am – 5pm irregardless of the weather outside (I have 6kw solar, with 675ah battery storage). I check the system daily for temperature, pH, and to assure the timers are all on time.

            I am currently reworking the website, and hope to have updates up in the next few weeks.

            As for how-to’s … While the daily investment to maintain a system is small, the initialization and attention to detail required during the startup is critical. Small systems, and kits are susceptible to such small incursions by insects, and can be endangered by temperature swings, and pH imbalances between the fish and plants. Starting small, and being persistent, with attention to detail to learn the signs and signals the species will offer when trouble arrives.

            Whether Hydroponics or Aquaponics, the learning curve is steep getting started. But once your system stabilizes, it takes very little effort to keep it so.

          • Harold Shaw January 29, 2023, 9:48

            Commercial greenhouses are opened to allow pollinators access to plants. Some vegetables can be pollinated by just shaking the plant. Plants in the nightshade family (tomatoes, peppers, eggplants) can all be pollinated this way. As well, their are cultivars of insectt pollinated plants that can self pollinate. However, they won’t breed true, the trait doesn’t appear in their seeds. They can be propagated through cuttings.

  • Brett Bellmore January 27, 2023, 7:10

    We’re talking about Mars, not the Moon. Are we really going to run into unweathered particles in significant numbers?

    I’ve looked at area productivity for hydroponics, and the numbers work out reasonably for a two level habitat structure where you have hydroponics upstairs, and do everything else underneath them. I do favor LED illumination, because getting natural light into a habitat in quantities sufficient for agriculture is going to be very infrastructure intensive. But you’re right that dirt farming makes more sense for some crops, such as fruits and nuts.

    Mars not only starts out with low light levels just due to its distance from the Sun, it’s subject to dust storms that can go on for months. Relying on solar on the Martian surface is very risky. I’d rather see an SPS or two in Mars stationary orbit beaming microwaves to the colony. Or maybe nuclear power.

    • Alex Tolley January 27, 2023, 13:54

      As regards unweathered particles, unfortunately, Martian dust is very abrasive. The Mars simulants are dangerous should small airborne particles be inhaled. No doubt the abrasiveness will depend on where the regolith is sourced, but at this point, the assumption is that like lunar dust, it will wreck seals, interfere with moving parts like bearings, and is a biohazard. That is why I include a point about mitigating the abrasiveness with water agitation, the same way one polishes rocks.

  • Harold Shaw January 27, 2023, 15:29

    Access to living soil and could very well be the most practical way to support healthy human biomes. As for the link to mental health, I have been gardening and keeping bonsai trees for decades and a nose-ful of living soil never fails to make me feel better.

    That being said…

    Fruit trees have been grown in pots for centuries and many trees can be trained to live in pots. My hydroponics system delivers higher, more reliable yields than my outdoor gardens. Hydroponic systems are also extremely simple. I can’t think of any part that couldn’t be 3D printed or any electric (besides lighting) function that couldn’t be converted to mechanical.

    On Earth, vertical hydroponic systems are more expensive than soil farming because the water and light are free. This difference won’t be true on Mars. Vertical hydroponic systems also don’t offer similar opportunities for economies of scale as soil farming. Hydroponic systems tend to require hand tending and picking, double production and we need to double the number of hands. With soil farming, we could double production and invest in more efficient equipment, the cost of tending and picking doesn’t double. Even at a million people, I don’t see where opportunities for economies of scale will appear for soil that aren’t also available for hydroponics.

    • Alex Tolley January 27, 2023, 21:00

      Very interesting. By any chance, are you using hydroponics and pot-based (or otherwise root-constrained) fruit trees? Where I live now, you buy fruit trees in plastic pots, then immediately plant them in the ground. Repotting them into a ceramic pot is not something I have ever seen. I will have to look into this. The only trees in planters that I have seen are ornamental, in restaurants and malls.

      If you created a bonsai orange tree, would the fruit be similarly scaled assuming the flowers can be pollinated?

      • Alex Tolley January 27, 2023, 23:59

        A quick Google search indicates I have been missing this aspect of fruit tree cultivation. There are even special dwarf varieties that are suited to pots and containers.

        Thank you for highlighting this as it invalidates my general belief that fruits and nuts cannot be grown hydroponically. Dwarf fruit trees certainly seem a viable solution.

      • Harold Shaw January 28, 2023, 11:18

        My crab apple is in a “soil like” medium and nutrients are delivered hydroponically. It took years for me to reliably get it to fruit. In general, fruit from container trees does tend to be smaller but I don’t know if this translates to a drop in nutrients/time into calories efficiency compared to natural grown fruit trees. Grapes can also be grown in containers.

        Over the long term, grapes and fruits trees may offer a ratio of useful calories to waste superior to other plants. On Earth and depending on the technique, apple orchards offer exceptionally high, perhaps the highest, calorie to acre ratio.

  • Alex Tolley January 27, 2023, 16:54

    I am starting from the assumed premise that starts with actors like the Mars Society, Musk, etc. wanting to settle Mars. Therefore the next question becomes how do you feed the colonists in a way that does not rely on a steady flow of food imports from Earth. This is even harder than the food supply from England to the penal colony of Botany Bay, Australia which took 2 – 3 months.
    Whether they can settle on Mars is another matter, for the reasons you state, and others especially travel times to the stars.

    I am not even sure a crewed scientific base on Mars, modeled on the Antarctic bases, is necessarily the right way to go, versus advanced autonomous robots that can manage to complete goals given to them. Consider the Insight lander that took a lot of remote control just to unjam its subsurface probe. If only the robot had the smarts to respond to a simple command like: “Try to move the probe to another spot where it can penetrate to the required depth” Insight being able to try various approaches itself until it either succeeded or failed and sent a message back: “Probe cannot be unjammed from here. What to do?” A rover with such a probe might be a better approach than an immobile lander.

    IMO, for scientific research, there will be an issue of how fast robotics and AI can develop by 2030 to compete with humans on cost and performance, and the overall cost of such missions. Private ventures can spend how they like, and scientific goals are not on their agenda. If they want to create a new [social/economic/religious] society, that is their business. I doubt any planetary protection issue will be observed by such people. But we can be certain they will want to eat while they are there, and unless they are certain that resupply ships will keep coming, they will want to make their own food.

  • Geoffrey Hillend January 27, 2023, 17:31

    First, we have to prove that Mars is really sterile. There is the ethics of bringing our life there which is alien to Mars. There might only be fossil remains of microscopic life that long has died out or maybe the environment of Mars was too hostile for life to have ever started. Consequently, we bring life to Mars. It did have a much thicker in the distance past billions of years ago and the Sun was less bright.

    The atmospheric pressure is a problem since there is no vapor pressure for liquid water. A glass greenhouse or bubble like those old Chesley Bonestell paintings of the surface of Mars settlements will work. It needs to have some type of E glass which will block out the UVC ultra violet light. Once the soil is in an Earth like atmosphere, some of the percolates like Carbon Dioxide will escape. One would have to choose an area where there was some permafrost since the Martian soil is bone dry. The problem is there is no carbon or organic matter in the Martian soil. We would have to fertilize the soil by adding the carbon and water and mixing it in with the Martian regolith The Martian soil is mostly minerals like silicon dioxide or quartz and ferric oxide or iron oxide, etc.

    As I wrote several years ago although we might have a large base(s) on Mars with many different rooms, the idea of towns is not too far fetched. However, the permanent colonization of Mars is a myth and obsolete. The reason being is that a life long stay on Mars will result in bone and muscle loss due to the lower gravity of Mars. This also rules out people being born there and growing up there as not anyone will want to have their children a human science experiment creating new Martians out of people. Elon Musk is still under than illusion, and I think was good for his inspiration to get people there, but in the future the real dangers of long term living on Mars will come out when we have an interplanetary rocket that can take more than astronauts there.

    • Alex Tolley January 27, 2023, 20:51

      Once the soil is in an Earth like atmosphere, some of the percolates like Carbon Dioxide will escape.

      Perchlorates are stable salts. Perchlorate contamination of terrestrial soils by industry doesn’t result in mitigation without chemical or biological treatment.

      The reason being is that a life long stay on Mars will result in bone and muscle loss due to the lower gravity of Mars. This also rules out people being born there and growing up there as not anyone will want to have their children a human science experiment creating new Martians out of people.

      That is a danger, but we don’t know how much. It could be mitigated by using carousels for some activities, such as sleeping. KSR’s “Red Moon” has Chinese bases use this approach to prevent the lunar gravity from causing long-term problems, although giving birth on the Moon was forbidden. This is why we really need an orbiting facility that can test the effects of different gravity levels. Start with animals like mice with short life spans to see if generations are crippled by lower gravity and whether there is an effect whatever it is. This is important because we are not going to have fewer 1g exoplanets to colonize than perfectly habitable planets with greater or less surface gravity. OTOH, if low g does not cause harm other than modifying one’s physique, then unless returning to live on Earth is paramount, why not allow such changes?

      • Geoffrey Hillend January 28, 2023, 16:58

        Excuse me for the mistake. I was not paying attention. I confused percolates with Percholorates. When the glass bubble or greenhouse is made on Mars and the oxygen atmosphere is added and the pressure increased until it is close to one Earth atmosphere, some of the water and trapped gas with escape. There will be percolates if an area of permafrost is used. Also I don’t see anything wrong with invalidating the obsolete idea the there will be permanent colonies on Mars. The reason being is that there can always be temporary stays especially as the centuries pass because our propulsion technology and interstellar rockets will get faster and it will be easier to make frequent trips and the Martian population could be continually replaced. There is no way one can remove the effects of a lower gravity and the growth of the human body over time. I agree that the Moon has a much weaker gravity than Mars, that problem will be increased and affect one more at a faster rate. Gravity is one of the first principles at this time we can’t manipulate. We can’t block it also and exercise machines can only do so much to counter the effects of an less than Earth gravity environment.

  • Adam Crowl January 27, 2023, 17:50

    Hi Alex
    Nice to see Vegemite getting a mention in the context of Martian food. Red Australian bull-dust reminds me a lot of Martian regolith, but of course even an Australian desert is wetter than Mars in the last couple of eons. Yet there is some water-cycle (eg. diurnal frosts) so I do wonder just how much surficial chemistry has modified Martian regolith. Certainly more than the Moon, but by how much? A lot can happen in the two or three eons since the last open water.

    • Alex Tolley January 27, 2023, 20:38

      The samples being taken in Jezero for a later return to earth may answer that question. Data rather than speculation about the literal ground truth.

  • gbaikie January 27, 2023, 19:34

    Exploration bases are completely different than settlements on Mars.
    With exploration bases, you import food from Earth, with settlements you export
    food from Mars.
    Mars exploration bases should determine if Mars is habitable for humans.
    One thing needed for Mars to be habitable is for Mars water to be cheap enough.
    I would guess water which costs $1000 per cubic meter [or ton] should be cheap enough. Or $1 per kg.
    For exploration bases, $1000 per kg is cheap enough, it cost more than $10,000 per kg. And you can import the water from Earth.
    So with Mars exploration one should explore Mars to determine where Mars water can mined at lowest cost.
    And to make water at lowest cost, you have mine a lot water within a short period of time. I would think you need to mine a million tons per year, and be able to mine a billion tons per year within 10 years.
    So for Mars settlements one should make lakes on Mars.
    A way to think about it, is you selling real estate on Mars, and real estate near lake is a lot valuable than land no where near a lake.
    And if mining Mars water at large scale and able to sell it cheaper, you export Mars water.
    And for Mars settlements you will need to use Venus orbit, using Venus halves the 2.1 years launch window of Earth to Mars and Mars to Earth.
    So if you cheap enough Mars water, you ship Mars water to Venus, cheaper than Earth water to Venus orbit.
    And the Moon might not have enough water to be cheap enough to ship to Venus.
    Or I guess, the price of lunar water to be used as rocket fuel, needs to be about $500 per kg, so lunar water might only be as cheap as, say $200 per kg.

    Also with enough Mars water it can used as coolant for nuclear reactor. Or Nuclear reactors on Earth use water as coolant- not using water would make nuclear reactor more expensive. And waste heated water, is not waste heat on Mars- rather it’s quite useful.

    Anyways make lake on Mars [don’t need a dome for it] and water evaporates from lake and it snows around the lake. Land with snow on it, is more valuable than land without snow on it.
    But as said, you start with 1 million tons, and if there enough demand, get to billion tons per year, and within decades, doing tens or hundreds of billion tons of water per year.

    And in lake, you can swim without spacesuit. Water depth creates pressure- and on Mars, what you lack is pressure.
    If imagine living underwater on Earth is possible, living underwater on Mars is easier, due to it’s lower gravity.
    One could launch and land rockets from lake on Mars.
    But you must make a lot water, for the mars water to be cheap enough to have
    settlements on Mars. But in terms exploration of Mars- it could cost more to mine Mars water at a small scale. One would grow food and mine water, more for experimental reasons- work out problems for Mars settlements.

    • Robin Datta January 28, 2023, 7:58

      Maybe water-ice comets in the Oort cloud could be steered to Mars?

      • Alex Tolley January 28, 2023, 13:59

        Isn’t that the premise of Fred Pohl’s ““Mining the Oort”?

        I maintain that Ceres is the most economic bulk water supply in the inner system, although it is saline and will need purification. A Ceres mining facility would be the “Saudi Arabia” of the inner system, providing water for life support and rocket fuel/propellant at the lowest costs with the fastest delivery times.

        • gbaikie January 30, 2023, 21:15

          “providing water for life support and rocket fuel/propellant at the lowest costs with the fastest delivery times.”

          To Venus orbit, where trillions of people could live- assuming you can make artificial gravity work [cheaply] like natural gravity.

    • Alex Tolley January 28, 2023, 14:41

      I don’t understand this idea of exposed lakes on Mars. There is no evidence that lakes will not boil off under low pressure. As there is no surface water snow away from the poles, this suggests that you are mistaken that the water boiling off will fall back around the lake as snow.

      Even if an exposed lake was possible, I don’t understand the logic of using the water as a source of pressure for subsurface habitats. I understand the idea as a radiation shield, but there are better alternatives. Pressure vessels can be easily made to withstand terrestrial surface air pressures. It is more difficult for greenhouses, but given that Open Ocean aquarium in Monterey, California uses glass to retain pressure of at least 1 bar and more at the bottom, transparent windows made from local resources are possible for greenhouses. Other pressure-inducing systems such as using regolith, or ice for transparency, can and have been suggested, making far simpler solutions, without the worry of leaks and the additional insulation and heat sources to keep the interior warm. [And there is always “transparent aluminum” for greenhouses and penthouse wall-size windows to enjoy the view from the luxury, cliff-face condos in the Valles Marineris. ;-) ]

      • gbaikie January 28, 2023, 22:47

        “I don’t understand this idea of exposed lakes on Mars. There is no evidence that lakes will not boil off under low pressure.”
        If boil off or evaporate and they are freshwater, the surface will freeze, and weight of ice causes pressure. But lower elevations on Mars you do have more pressure, and most think water at 5 C doesn’t boil when pressure than average Mars pressure.
        If have saltwater, one have solar ponds with frozen surface and much warmer below- there are natural solar pond in Antarctia which have a frozen surface.
        “As there is no surface water snow away from the poles, this suggests that you are mistaken that the water boiling off will fall back around the lake as snow.”
        There is snow in Mars not in polar regions, the Viking probe took pictures of it- but was thought to be mostly frozen CO2. But not saying that proves anything. Also you could settlements in polar regions. With Moon and Mars there advantages to being in polar or near polar regions.
        With Moon there area which have sunlight 85% of the time per year, the Mars tilt prevents this, but one could get more sunlight in polar regions as compared elsewhere in Mars. And there is shorter distance from different time zones. Since moon is smaller, this better with Moon, but Mars being smaller than Earth and on Earth because it’s thick atmosphere, the polar regions on Earth worst place to harvest energy. Point is it’s short distance to have grid with say 3 time zone. which allow 2 hours of sunlight per day as compared to being only 1 time zone.
        But if in one time zone on Mars higher elevation [or being on edge of deep basin, such as Hellas Basin will give more than 12 hours day on average of solar energy.
        On earth a metric of solar power is the term peak solar hours, which is at best averages 6 hours on day, and on Mars on time “peak solar hours” for 12 hours due it’s thin atmosphere. So, you get 600 watts of sunlight for 12 hours.
        Or 12 times 600 is 7.2 kw hours on average day- anywhere on Mars {not counting topography advantage- though obviously there could be topography
        disadvantages- and not counting that either. Btw since Hellas is so big, merely being in basin wouldn’t neccesary, have a disadvantage or could on hill in basin, and get more than 12 hours].
        Of course a level surface at Mars pole get low angle sunlight and isn’t heated much by sunlight, but solar panels, you have at angle so get the most sunlight. The advantage of more hours per day is less need of battery storage,
        plus getting more solar power, than you get on Earth.
        But if have say a 2 km diameter lake and it was evaporating, it seems to me the area on lake and near the lake would have more water vapor in the air.
        The average amount water vapor on Mars is 210 ppm but near the lake, it seems it could be twice the global average [or more]. And at some distance from lake, say 500 km away, the lake would change the average amount water vapor. Or without lake say it was 210 ppm, and with lake it might be say 215 ppm.
        But my point was you have make a lot water. And as assumption, I think get water from drilled well. Or not assuming mining permafrost or even blocks of solid ice. If mining Mars like one mine coal- people could live in “the coal mine” and you don’t make a lake. But I think finding liquid water and pumping is the cheapest way to make water. But it seems might just drill a water well and all got was frozen ice, which need to melt, before it could be pumped.
        So, I am talking about something which may not exist- there may not be any liquid Mars water or it could be so deep, it’s not accessible.
        But if can’t get cheap water, I don’t think Mars is habitable.

        • gbaikie January 29, 2023, 16:47

          I don’t think Mars is habitable, yet.
          And Low Earth orbit is not habitable, yet, either.
          Living for 6 months in LEO and coming back to Earth crippled,
          is not habitable. And NASA has failed to test artificial gravity, which
          could possibly make LEO, habitable.
          And we don’t know the effect of living more 6 months in the Moon or
          Mars does to human body- we don’t know effect lower natural gravity is.

          Why live on Mars, instead of living on Earth oceans?
          Such argument is usually about idea that going to Mars is expensive and
          I suppose one could say that on ocean you could breath air- as long as you can keep floating on the ocean. A problem with the ocean is the waves and a lack of freshwater. You make freshwater from sea water, but need energy to do this, an easier way is to bring water from land areas.
          A problem in Africa and elsewhere, is people don’t have indoor plumbing- in terms industrial revolution standard, that is not very habitable and cost carrying water from well, is high.
          The idea that one pay more than $1000 per cubic meter, assumes you can afford it. Few people in the US could afford it. The US uses 600 billion cubic meter of water per year, at $1000 per cubic meter, that is 600 trillion dollars.
          I assume people can afford $1000 per cubic meters, because it will be worth, using less water [severe water conservation] and they living in an growth economy and labor costs are high. And you could it’s deflationary
          ecomony- things cost a lot in the beginning and become cheaper in future. And if there are taxes, they start high, and lower over time. Or no taxes, and taxes added over time.
          Or assumption is you start with water at $1000 per cubic meter, but as economy grows, it become lower in future. Or property value increases, while water lowers in price.
          You could have trillionaire spending trillions, and people going there are renting, but land with access to cheaper water, controls land value. As it does on Earth.
          Having access to electrical power is also related to land value, and with Mars having access to hot water could important. One could do solar thermal energy, but I would guess, solar power to make electrical power is better on Mars, than on Earth. But solar thermal is better on Earth than Mars- if below say 45 degree latitude on Earth. So I use nuclear power to make hot water on Mars. You might need a trillionaire or a government to make and operate nuclear power plant on Mars. And it terms solar power grid, also need a large investor or government.
          But it’s possible the Moon has trillions of tons of mineable water- and Mars doesn’t and possible Moon doesn’t have mineable water and Mars does, having either, could lead to both being habitable.
          And both could have mineable water, and neither are habitable, yet.

          • gbaikie January 30, 2023, 2:36

            –Since Mars has a surface gravity of a little more than one-third Earth’s, its crust is less dense and more porous than that of Earth. Previous research suggested that this means that more water can leak underground. “I consider it likely that there are deep pockets of water in the martian crust not yet detected,” McEwen said.

            However, “these are not shallow aquifers,” McEwen said. Karunatillake concurred, noting that these subterranean aquifers may reside miles below the surface. Volcanic outgassing of water vapor from the martian mantle may intermittently replenish these aquifers, Karunatillake said.
            Lava tubes, which are natural tunnels within solidified lava, might host subterranean aquifers, Karunatillake said. For instance, there may be lava tubes at or near the volcano Arsia Mons on the Tharsis bulge near the equator of the planet Mars. “Given how deeply lava tubes may go, they might be analogous in a distant sense to the kind of aquifers we see in Hawaii,” Karunatillake said–

            It seems one could drill as much as a mile, but not miles.
            The lava tubes could be deep enough and could be another option- but in that case you aren’t making lake, you have a lake or tunnel full of water and due to depth, you have more air pressure.
            But seems rather hard to explore for, and seems one should first be looking water less than 1000 meters under the surface.
            And seems need crew on Mars for this, and the crew on Mars can be using robotic missions- better, than from doing it from Earth.

            • Project Studio January 30, 2023, 11:38

              Yes access to water at a sustainable cost is one of the key contributors to making Mars habitable. Wondering how deep one has go – into Mars – before the atmospheric pressure makes a pressure unnecessary, or which allows running water not to rapidly boil away?

              Not deep enough:

              “Valles Marineris has been a focal point for climatic studies on Mars for some time. Measuring 4,000 km (2,500 mi) long and up to 7 km (4 mi) deep, it is the largest canyon system in the Solar System. This depth is also why atmospheric pressure at the bottom of the canyon is believed to be higher than most places on Mars – over 1200 Pa. On average, atmospheric pressure on Mars at “sea level” is 0.636 kPa, less than 0.5% of what we experience here on Earth (101.325 kPa).

              According to new evidence obtained by the orbiter element of the joint European-Russian ExoMars mission, there is plenty of water ice at the bottom of this valley…”


              “At 23°C, for example, water would boil at a pressure of about 21.1 torr, or about a fortieth of atmospheric pressure.”

              • gbaikie January 30, 2023, 18:05

                On Earth you have solar ponds in which the sunlight heat water below the surface to about 80 C.
                Likewise with Mars you could have solar pond with water at about 30 C if water is about 1 meter beyond the surface- and water surface could be ice.

  • charlie January 27, 2023, 20:19

    ” Kokkinidis raises the issue of animal meat production for various cuisines, but in reality, the difficulties of transporting the needed large numbers of stock for breeding, as well as the increased demand for primary food production, would seem to be a major issue. [It should be noted that US farming occupies perhaps 2% of the population, yet most commentators on Mars groups seem to think that growing food on Mars will be relatively easy, with preferred animals to provide meat. How many Mars base personnel would be comfortable killing and preparing animals for consumption, even mucking out the pens?]”

    dont agree. animals meat gives flavor and variety; consumes excess plant matter.
    “…Mars base personnel would be comfortable killing and preparing animals for consumption, even mucking out the pens?” – that’s Robot work …

    • Alex Tolley January 28, 2023, 14:25

      Industrialized animal husbandry and slaughter, however necessary today, is certainly getting pushback from consumers. Despite the “I will never eat meat substitutes” from die-hard meat eaters, the investment community is well aware that a fraction of consumers in the rich world would switch to substitutes if they were price comparable. I recently tried both “Beyond Meat” and “Impossible Meat” while available on deep discount and both were acceptable ground meat substitutes. There are claims that 3-D printed steaks and bacon have fared well by experts, but even if true, must prove themselves in the market at affordable prices. As in “Soylent Green”, it may be that only the wealthy will be able to eat real meat products, whether legally or not.

      Clarke had suggested that eating real meat from animals may become unacceptable in the future. Some vegetarians I have met found it revolting to be near others eating meat. Even meat eaters find watching others eat very rare “bleeding” meat unsettling. Then there are food preferences. Some people cannot stand the thought of eating fish or shellfish. Eating “crunchy” insects is not something I would do, even though I eat shrimp and prawns, sometimes with parts of their exoskeletons. Go figure…

      You will have noticed that there is already a strong market for non-animal milks (soy, almond. oat) despite their price at several times milk prices. In California, the choice is about taste and water consumption. [Almond milk is ridiculously water-consuming in this regard.]

      In summary, I believe that the rich world is showing the way to eventually eliminating animal meat [for all but special occasions (whole turkey for thanksgiving in the US, and Xmas in the UK) ?] and switching to both environmentally friendlier and morally acceptable food production. If technology can solve the price issue, I think that taste will become a minor issue, as many meats are now a pale shadow of their earlier farmed tastes. For example, pork is very mild tasting today, yet I have eaten a hand-raised hog that was far tastier. Similarly, free-range chickens do taste much better than caged chickens. Yet we accept the industrialized meat flavors as “normal” despite their lack of taste. [Chickens sometimes have to be injected with “chicken flavor”, and fish-fed chickens do, surprisingly, have a faint fish taste.] So it may be that our future Martian (and space) settlers will eschew animal husbandry and be mostly Vegan/Vegetarian.

      • Adam Crowl January 28, 2023, 18:24

        Hi Alex
        I tend to agree though I think a case can be made for using microbes rather than macrophytes.

  • Harold Shaw January 28, 2023, 11:34

    I harvest and process wild and domestic animals for food. Roosters especially are always on thin ice. I wasn’t raised as a hunter or homesteader and had to learn how to navigate not just squeamishness but taking the life of a conscious being. For me at least, living on a life filled world where predation was a trait I shared with so many other lifeforms is an essential coping mechanism. I don’t know if I could view the sterile Martian landscape and kill another conscious being unless I really had to.

    Animals are a luxury item because they are an inefficient source of calories. The efficiency of Martian food production will be directly proportionate to the number of Martians and their food security.

    Chickens are filthy animals, I wouldn’t be surprised if the life support requirements for 2-3 chickens equal that for one human.

    • Mike Serfas January 28, 2023, 20:12

      Interesting question! I think we can work out the life support from basic principles. From https://justagric.com/chicken-feeding-guide/ I see that broiler chickens eat feed that is about 3 kcal/g, which is to say about 75% of a pure carbohydrate (or protein) diet, I assume due to insoluble fiber. They say it takes 2.5 kg to 4 kg to feed a chicken to market weight … depending on the age at slaughter (6-8 weeks?). I see similar blur in other web figures that say 1/4 pound per day or 1 pound per week, depending on age. This seems a little hard for me to nail down and someone else may have better figures, but let’s say 70 to 100 g feed = 210 to 300 kcal = 53 to 75 g CH2O or equivalent per day on average. Husky, out-of-shape Earth humans eat ten times that, but small-bodied trim colonists might get by with significantly less, unless the heat goes out.

      The general reaction for burning carbohydrate is CH2O + O2 = CO2 + H2O, so (53 to 75 g)(1 mol CH2O/30 g)(24 L O2/mol) = up to 60 liters of O2 per chicken per day. (I don’t know whether a Mars colony atmosphere needs inert gas added to that, nor how much; but if it’s like on Earth, that’s 1/3 of a cubic meter of air used up per chicken per day. Like humans, who inhale 8-9 cubic meters of air per day but only consume a quarter of the oxygen in it, the chickens will actually breathe a greater volume than this, but most of that can be reused)

      Overall, I’d think 7 chickens might count as 1 crew slot in the colony. This is only perhaps 55 pounds of chickens, but they have a high metabolic rate and body temperature around 106 F. Since they are helping to heat the habitat, the waste of energy from using warm-blooded animals isn’t as egregious as it seems. Think of it as a high-tech reprise of peasants sleeping over their livestock for warmth.

    • Brett Bellmore January 29, 2023, 20:15

      The inefficiency of eating meat is actually a source of food security; When you have a poor harvest, meat eaters can always move “down the food chain”, and eat plants. Plant eaters don’t have the option of eating fertilizer and sunlight.

      The vegetarian approach to life support on Mars is actually closer to a “just in time” system, since the temptation is to cut corners and reduce margins, such as accumulating stored food, as they represent inefficiencies when things are working. I think we’ve seen in recent years how dangerous cutting margins like that can be.

      I’m confused by the suggestion colonists would be squeamish about slaughtering chickens or rabbits. Colonists are not a representative sample of humanity, and people who have no problem dressing a chicken or gutting a fish are a dime a dozen. The squeamish are simply not going to be going to Mars in the first place.

      Nor is bringing animals that great a burden. It’s not like every colonist has to bring a flock. Small animals like chickens or rabbits reproduce very rapidly, you can turn a breeding pair into a flock large enough to feed dozens in a couple years. To be sure, the first couple waves of colonists probably won’t be bringing livestock; The first wave will be relying mostly on food shipped ahead so that they can concentrate exclusively on building up habitats, and the second wave might be resigned to a few years of being vegetarians, but by the third wave you’ll likely see animal husbandry on Mars. Perhaps first as a luxury item, and, of course, eggs long before chicken dinners.

      A lot of the discussions of colonizing Mars tacitly assume a totally planned economy, and that might be a realistic approximation for the first wave. But entrepreneurship will diversify the food options VERY rapidly, even if planners have other ideas.

      • Alex Tolley January 30, 2023, 1:18

        But entrepreneurship will diversify the food options VERY rapidly, even if planners have other ideas.

        That should be encouraged. I imagine that cooks and chefs who can be very creative with foods and flavors would be welcome on a base. The ability to create different, tasty meals would be important for morale, IMO.

      • Harold Shaw January 30, 2023, 12:18

        Why would a vegetarian diet encourage not storing food? This argument flies in the face of the history of agriculture. Excess calories don’t exist unless production passes an efficiency threshold. For goodness sake, if your argument here were true the transition to an agriculture wouldn’t have resulted in modern civilization.
        The premise that the first waves will be vegetarian and that meat is a luxury undercuts your first argument that meat based diets are more secure than vegetarian. If meat based diets are more secure and better at providing calories, why wouldn’t they be used from the start, when the colony is most vulnerable?

        All that being said, I agree that meat will eventually make its way to Mars. Meat will bring variety to diets and for first world mentalities, signify that they have passed a threshold for mastery of their new environment. But that does not change the simple truth that the more energy and space dedicated to inefficient meat production like chickens, the fewer colonists can be fed and fewer calories will be available for storage.

  • Harold Shaw January 28, 2023, 11:55

    Fruit trees such as pears and apples where fruit appears at spurs can be trained to take up very little space thus achieving very high ratios of space to calories.


    Some nuts also grow from spurs.

  • Dave Moore January 28, 2023, 17:09

    I envision the first major Martian base to be built as follows:

    Under the Northern plains of Mars somewhere near the Phoenix lander site where there is a layer of regolith over subsurface ice, the base will be built by first removing the surface soil above the ice inside a metal ring. The exposed ice will sublimate away. Any soil will be removed. Another metal ring will be added–and so on until a 100 ft deep shaft has been sublimated into the ice (heat may be added to speed up the process.)

    At this depth, the over pressure of ice under Martian gravity is approximately 15 psi. A sideways shaft will be sublimated away and an airlock installed, and the area on the other side will be pressurized. I suspect it will be a bit less than a full Earth atmosphere. If the temperature is kept below freezing, the ice will be stable.

    I suspect the base will consist of access tunnels with rooms hollowed out on each side of them. Inside the rooms, on blocks, will be lightweight foam structures with aluminized interior walls with the interiors kept at room temperature.

    Power will be from a modular reactor on the surface, so your agriculture will be done by hydroponics under blue/red LED lighting (plants don’t use green). Also note, modern hydroponics is not done with baths of water. Mist is sprayed onto the plant roots.

    Extensions to this sort of base can be done easily using an ice chipper, so room for agriculture can be made easily–within limits.

    Single-celled algae can not only be grown for animal feed, by can also produce the precursors to plastics, which would allow 3D printing of replacement parts, and the production of the aforementioned foam paneling.

    This sort of base would be fairly self sufficient with in situ production of food and construction supplies and chemical fuels.

    • Alex Tolley January 28, 2023, 21:43

      The British Interplanetary Society produced a technical report on a Martian base at the Martian North Pole: Project Boreas – A Station for the Geographic North Pole. It is a collection of BIS papers outlining base design and mission. It is quite comprehensive. Their principle design is more like the surface bases in Antarctica. Whilst your design is based on using the ice to shield the base from ionizing radiation, the Boreas work suggests that a polar location benefits from the greater depth of atmosphere to shield the personnel and that a storm shelter is used for severe solar storm events. ISRU is harnessed to reduce construction mass. The rationale for a polar base is to be able to take ice cores and use them to understand the history of Martian climate, weather, and surface conditions. I think your favored location might offer a similar opportunity, although it is also close enough to the north pole to make treks there to do the ice core drilling.

      Whenever a heated structure is placed in ice, there will always be some leakage of heat into the surrounding ice. The base must be well sealed to prevent meltwater from entering, and potential structural shifts. One could add heat pumps to keep the outer hull of the habitat very cold to prevent thermal effects, and vent excess heat onto the surface. Apart from radiation issues, I would have thought the best place to start is with recent Antarctic base designs, modifying them to be able to be sealed to maintain atmospheric pressure and adding real airlocks.

      • Dave Moore January 29, 2023, 15:35

        I kept the details of my station sparse as I wanted to it to refer to the topic of the main post, agriculture.

        I envision any cooling of the room temperature modules to be done with station air, and cooling of the station itself done by compressing the Martian atmosphere then letting it expand through a counter current heat exchanger with the station air.

        To get some idea of what I envisage, just Google Norwegian Ice Hotels. These are built of ice on the surface rather than tunneled into the ice, but the principle is similar. They are built anew each year, so this implies that the cutting and carving of ice is a relatively simple job. Their interiors are kept at -4°C (room temperature to Norwegians), and unlike my proposal they don’t have warmer modules inside. You sleep on the ice on a foam mattress in a warm sleeping bag. It can be quite comfortable they cheerfully inform us.

        Thanks for your pointer to project Boreas.

    • Jer January 29, 2023, 11:43

      Building sub-surface structures requires:
      significant pre-dig investigation (including boreholes, etc., to understand the quality of the soils – very little reason to believe that the soil type, bearing (ability to support weight without moving, shifting), and its local integrity (foreign layers, pockets, boulders, etc) is homogenous for multiple storeys down (even if we are ‘shelling’ (100% walled area enclosure) as we go; and,
      supporting sub-surface structures (even vertical shafts, but especially horizontal stubs and corridors/circulation) requires very robust support, often by materials (shells) or systems (3d-, domed, cylindrical trusses/ frames) in limited supply/ great weight/ unwieldy proportions/ challenging connections/ anchorage.
      Without having investigated much (or read too many above comments), I lean more towards covered ditches and caves with multiply-redundant inflatable structures inside – possibly in clusters with inflated corridors/ passages between.
      What was the current thought above getting people around on the surface? buggies, copters, blimps…

      • Dave Moore January 29, 2023, 16:28

        Jer, the material this station would be tunneled out of is dirty ice, ice with some Martian dust mixed in.

        I would envision that the initial reconnoissance would be done with deep radar, and a robotic rover would drill cores to confirm the suitability.

        Ice has plenty of structural strength to support itself, particularly under Martian gravity. 100 ft down on Mars is equivalent of 38 ft down on Earth. The downward pressure on the ice would be about 17 p.s.i. while the interior outward pressure of the station would be, I envision, something like 12 p.s.i.

        Repairs to cracks in ice are simple. You use a 50/50 mixture of water and alcohol. The alcohol evaporates quickly chilling and freezing the water.

        I would expect there to be some surface structures: repair shops for vehicles etc. But these can be evacuated in the case of solar storms, and people working in them would retreat under-ice when not working to keep their radiation count down.

        You may even have a sloped tunnel/ramp running from the surface down to the station to allow buggies to be drive directly in and out of the station. Remember, it is very easy to excavate a 100 ft deep pit in this region of Mars (68° North). All you have to do is keep removing the surface soil and sublimation of the ice does the rest.

        I would envision the station as being a resupply point for mobile research stations. For example, if we take Elon Musk’s Starship upper stage, which he proposes to land on Mars, tip it on its side, and add 4 large wheels and a drive train, then we have a 15 ft diameter by 150 ft long space from the fuel tanks, plus whatever is in the payload compartment. This could be fitted out as a excellent mobile research station.

  • Dave Moore January 28, 2023, 17:11

    I forgot to add that this type of base could be built and tested under the ice in Antartica before being deployed on Mars.

  • Michael January 29, 2023, 9:57

    Once established we could give mars a global magnetic field via two super conducting coils one at each pole. The poles are cold enough to aid the superconductivity required and there is the chance once the field builds up it will cause a permanent magnetisation due to the large amounts of iron in the crust.

    • Alex Tolley January 29, 2023, 22:06

      That is probably a future infrastructure project. Ideally, it needs a high-temperature superconductor that will operate at the local polar temperatures. I think I have seen this idea suggested many times on the Mars Society FB group, although I have no idea how it can be done and the performance it delivers.

      • Michael January 30, 2023, 14:56

        It could be started here to enhance the field there to cover a large area.


        The most likely design is large tubes cut into the regolith with a diameter of 30 odd km’s stacked and covered, each tube would be filled with say liquid nitrogen to allow superconductivity within. Each coil added is powered up to enhance the local field until it connects up with a northern one built later. The planet itself will act as a giant magnet reducing the power and size of the coils and may become a permanent magnet without the need for the coils to be on. Truly a mega mars project.

        • Alex Tolley January 30, 2023, 16:32

          As LN2 is liquid at a much lower temperature than the Martian poles, the containers will need to have the power to maintain the N2 in a liquid state. Any idea how much mass is required for the coils and containers, and the power to maintain the N2 in a liquid state?

          As you say, a truly mega project, and probably part of a terraforming project.

          • Michael January 31, 2023, 9:04

            My estimates a few million tons for the whole lot BUT its modular and we have a starting field which protects a large area already. We only need a field of about 1 tenth of Mercury’s or 1 thousand of earths to offer good protection but its not perfect against big sun blowouts. The power to build the field would be either nuclear power or solar.

          • Michael February 1, 2023, 8:38

            There is another way by using a cryogenic liquid pumped around a large buried electrically insulated tube or tubes. Liquid helium could be ideal because of zero resistant to flow at very low temp but difficult to bring about due to cost and supply. You have the liquid in the tube pumped around at high speed and you suspend same charged particles within. The movement of the charged particles in the flowing liquid creates the external magnetic field.

            • Alex Tolley February 1, 2023, 17:10

              Would a plasma magnet held as a statite over the poles work to provide the protective magnetic field? The advantage is that the solar wind provides the magnetic field as it is induced to move. The main issue is that the orientation isn’t right, but just maybe that can be fixed with some creative engineering. The huge reduction in mass requirements would seem to make this a more elegant solution…if it is workable.

              • Michael February 4, 2023, 6:45

                Not sure about statite due the forces involved once the field powers up, also getting the power up there could be a hurdle. As for a superconducting coil Magnesium Boron, both found on Mars, may do the trick, by an estimation we need a 500 to 1 million A conductor which would not be very thick in a tube cooled to around 10 to 20 K. As stated before it can be built as a modular design and more than likely the planet will aid the field build up as it has a partial field already.


          • Michael February 5, 2023, 8:58
  • Mike Serfas January 29, 2023, 13:19

    Hmmm… could farming be done at near-surface conditions, provided it is under a membrane and you control the temperature with large mirrors and thermal ballast? Mars has thirteen times more CO2 than Earth. If we keep water vapor confined, liquid water is in equilibrium with 18 torr of water vapor at 20 C (100% relative humidity). A membrane over this would not need 15 pounds per square inch of bracing, but only 0.35 psi, and if there are night cycles with membrane temperature down to near freezing to allow “rainfall”, this might be reduced nearly 4-fold further. With Mars atmospheric pressure as high as 1155 Pa at Hellas Planitia, and Earth life content with 20 Pa, I think it should even be possible to maintain nightly liquid water rainfall and 50% relative humidity at a daytime 20 C without any pressure bracing under a membrane that passes CO2 slowly, provided the waste oxygen is immediately taken up chemically for later indoor processing.

    Current research in carbon capture membranes for emissions reduction has generated a variety of selectively permeable membranes that favor CO2 passage more than 20-fold over N2 ( https://phys.org/news/2019-07-next-gen-membranes-carbon-capture.html ). To be sure, I still don’t understand why natural plants, despite having cell membranes that pass CO2 but not water, seem unable to do this relative to dry air without resorting to timing when they open and close spiracles — but if you can make a membrane that traps H2O but not CO2, it should be most valuable to Earthly farmers also.

    The perchlorate could be dealt with by perchlorate-reducing bacteria expressing pcrA or pcrAS, which are being developed for environmental remediation on Earth.

    Plants do need oxygen for respiration, but I’d imagine a careful combination of artificial light, allowing some accumulation of oxygen partial pressure, and inserting genes such as plant hemoglobins might help to paper this over.

    • Alex Tolley January 29, 2023, 22:02

      It might be fine, except for the exposure to radiation. Ideally, the ag area should be protected from radiation and the light directed into the greenhouse with mirrors. The same applies to greenhouses on the Moon.

      Plants don’t like being in a high concentration of CO2, so best to make most of the partial pressure by extracting nitrogen from the atmosphere.

  • Mike Serfas January 30, 2023, 10:21

    To me the biggest unknown about Martian base designs is how much inert gas humans need to survive comfortably. Mars has a tiny amount of N2, and nitrates in the soil, but these are needed for every sort of protein biomass and many desired chemical products. More importantly, Earth-like N2 quintuples the pressure requirements. Does anyone know what results have NASA has for how much added N2 would actually be needed in a low-pressure atmosphere otherwise containing only oxygen, water vapor, and traces of CO2?

    • Alex Tolley January 30, 2023, 12:54

      Nasa is using 8.2 lbs/sq in pressute – 66% N2, 34% O2. Modeling a 15-min extravehicular activity prebreathe protocol using NASA’s exploration atmosphere (56.5 kPa/34% O2). This is almost the exact same pressure as on the Tibetan Plateau which we know is inhabited, even if it takes some adaptation.

      Too much O2 and the probability of fire increases. For deep sea diving and habs, He can be substituted for N2, but with the effect of raising the pitch of speech.

      While N2 is a small component of mars’ atmosphere, it can be readily extracted by simply freezing out the CO2, a much easier task than separating N2/O2. We also have oxygen concentrators for those with breathing problems. These would be good on Mars where the pores in a membrane can easily block CO2 from crossing it, compared to the N2.

      • Mike Serfas January 31, 2023, 10:12

        Very interesting link! A key search term is “exploration atmosphere”; another useful link is https://humanresearchroadmap.nasa.gov/evidence/other/ExpAtm.pdf

        Some exploration atmospheres… (EAWG = Exploration Atmosphere Working Group, psia = absolute PSI; mixes accurate to +- 0.2 psia, +- 2% O2)
        14.7 psia with 21% O2
        10.2 psia with 26.5% O2
        8.0 psia with 32% O2 (EAWG, 2005)
        8.2 psia with 34% O2 (EAWG, 2012)
        3.5 to 8.0 psia with 100% O2 (EAWG 2006, EVA only; most often 4.3 psia?)

        According to the link above, risks from hypobaric hypoxia appear to be greater than from normobaric hypoxia (i.e. O2 partial pressure isn’t quite the whole story), but it is still under investigation.

        The 100% O2 atmospheres are limited to EVAs due to fire risk. The very lowest pressure 100% oxygen atmosphere (3.5 psia) is still >10% more O2 than Earth. Questions… I haven’t seen whether people can tolerate these atmospheres for longer than an EVA. I also haven’t seen anything to tell me if a a 3.1 psia atmosphere (if it can be tolerated at all) would truly increase fire risk per se, or whether the risk is from compressed O2 encountered incidentally.

  • ljk January 30, 2023, 12:50

    Mars meteorite with organic molecules holds clues to chances of ancient life

    By Robert Lea

    Published 17 days ago

    The meteorite, which crashed down in Morocco 11 years ago, was formed hundreds of millions of years ago.


    To quote:

    A Martian meteorite that crashed in Morocco 11 years ago contains a vast diversity of organic compounds, which could help researchers discover if Mars could have hosted life and provide important clues about Earth’s geological history.

    “Mars and Earth share many aspects of their evolution, and while life arose and thrived on our home planet, the question of whether it ever existed on Mars is a very hot research topic that requires deeper knowledge of our neighboring planet’s water, organic molecules, and reactive surfaces,” Philippe Schmitt-Kopplin, of the Technical University of Munich and Helmholtz Zentrum Munich in Germany, said in a statement.

    The meteorite, named Tissint after the town in Morocco where it was found, is just one of five Martian meteorites that have been observed as they’ve fallen to Earth. The rock was formed hundreds of millions of years ago on Mars and was probably launched into space by an explosively violent event before falling to the surface of our planet.

    The researchers also found an abundance of organic magnesium compounds, which had not previously been seen in Mars samples. These compounds could shed light on the high-pressure, high-temperature geochemistry that shaped Mars’ deep interior. The abundance of this type of organic magnesium compound could also point to a connection between the carbon cycle on Mars and the evolution of its minerals.

    The team is now looking to samples returned from the Red Planet by future missions — including Mars Sample Return, a proposed joint mission of NASA and the European Space Agency — to provide geological data about Mars. This information could vastly improve our knowledge of the formation, stability and dynamics of organic compounds in ancient Martian environments.

    The team’s research was published Jan. 11 in the journal Science Advances:


  • tesh January 30, 2023, 14:24

    I wonder if this fascination with “but chicken may be able to fly on Mars, oooh” is just so much more naval gazing, much like eating vegetables – let alone meat!

    Why complicate things. Build machines and factories that produce food. All of this but you need this fruit or veg or animal is just giving into a romantic view of a frontier mentality that was anything but romantic – just move on already. Machines/factories that make food are going to far more efficient than having plants and animals and all the people and tech to maintain them. And, the notion that we cannot make/synthesize food that is both nutritious and tasty is just so much more hypocritical (and nonsensical) in light of the massive amount of tech we do not have to actually get to Mars – let alone make it “work out”, and yet, take it for granted that those tech will be delivered….

    • Alex Tolley January 30, 2023, 16:28

      The problem is mass and the many parts to make the food production factory. All this has to be lifted from Earth, delivered to Mars, and then assembled and run. This is far more onerous than letting animals and birds grow by themselves while being fed. When the colony is large, that is a different matter, but the early stages will need to be as resource-sparing, yet robust, as possible. Mistakes cannot be recovered from. We are not talking about a lab setup but a production facility. Even the simplest food production processes that supply the nutrients for a small base of perhaps 50 – 100 people must generate the calorific needs of those people by cell reproduction and then processing.

      e.g. Daily calorie intake per person = 2400 kCal.
      1 g of carb or protein = 4 kCal.
      Therefore 600 g of dry protein & carbs needed per day.
      For 100 people, that is 60 kg, or 600 – 1200 kg wet food/day (assuming 90% water content).
      Say around 1 tonne per day. Assuming algal or bacterial cells, that is a cubic meter of cells. That might mean a reactor that can double its cell count per day would need to be about 10-100x in volume. This must work perfectly and reliably. It is the ultimate “just in time” food production. This is just the bioreactor. Then there is all the equipment to supply nutrients and to process the goop into something palatable.

      Note that assuming a 2 year delivery schedule of dried food to Mars, each delivery will require a 43 MT payload of dried packaged food that is rehydrated with local water. That may be the best way to supply the colonists, especially as existing food packages for space can have production scaled up to meet the demand. A more acceptable form of the food might be frozen, or shelf-stable dry goods like raw and processed grains. The tonnage would be greater, but the conditions on a cargo ship could facilitate cold storage, and Mars is already cold enough to maintain bulk food storage in a frozen state. Perhaps this would be a profitable business for an adventurous grocery corp.

      Clearly, local production of food will be cheaper than imports from Earth. If seeds can be shipped, they can become the base for agriculture, whatever the techniques used. So much easier to grow crops and consume their production directly of with an efficiency loss via animals.

      When the colony is large and there is a chemical industry available, then synthetic food might be the best way. But until then,technologically assisted agriculture is probably going to be the mainstay of food production.

      • tesh January 31, 2023, 13:11

        Alex Tolley January 30, 2023, 16:28
        The problem is mass

        Is it any more?

        Also taking animals there means having vets, growing things they eat and a whole slew of tech (and research) to support that. Biology is complicated. Adding more biology adds more complications and, unknowns.

        Take/make a machine and it becomes a problem of components.

        • Alex Tolley January 31, 2023, 22:53

          Until you can manufacture locally or have extremely inexpensive space access and delivery, then mass will always be an issue.

          Life is far more resilient and adaptable, and of course, a key trait is reproducing. We have a long history of cultivation and husbandry, so I think that suitable crops and animals will be your relatively low-mass seed and brood stock. Of course, we need to test out the ideas on Earth first to make sure they work. If they don’t, then food delivery may be needed until some other method can be reliably started and maintained.

  • Henry Cordova January 30, 2023, 17:35

    Sorry Alex, I just couldn’t resist it…


  • Harold Shaw January 30, 2023, 17:44

    Rather than growing plants, such as hemp or bamboo, specifically for building materials, waste cellulose could be used. This would free space for more people or more varied food sources.



    • Alex Tolley January 30, 2023, 22:24

      Some years ago cellulose nanofiber was shown to be extremely strong. Yet surprisingly, despite fairly easy manufacture nothing much was heard of it. I’m pleased that the 2 links show a modified form of cellulose that can be 3-D printed to make tough artifacts. Perhaps with newly engineered wood materials, we might now be able to build structures and make artifacts from this very common biomaterial that can be repurposed and recycled. I would like to see an example of that printed lump machined and polished as a possible plastic substitute.

  • Paolo January 31, 2023, 8:29

    At the times of 2001 and Star Trek, we didn’t know of the existence of the biome we live with.

  • Michael Fidler January 31, 2023, 8:42

    Put AI robots like Musk’s on Mars, no need for meat, food just sunlight or nuclear batteries. Let them build the infrastructure and then send the humans…

    • Alex Tolley January 31, 2023, 22:47

      I’m with you on this. Watch this space.

  • Michael January 31, 2023, 10:52

    A key to our foothold on Mars will be lava tubes, they can have many uses.

    Underground habitats.
    Water Storage.
    Soil creation areas.
    Non photosynthetic food generation.
    Air storage.
    Compressed CO2 storage for electrical generation, day and night and during dust storm.

    Too name a few

  • Ljk February 1, 2023, 9:41

    Can you grow plants in Martian soil if you add human waste?


    • Alex Tolley February 1, 2023, 17:25

      Amusing as that video is, the reality is that any extraterrestrial habitat will be exemplary in nutrient recycling both nitrogen from treated fecal matter and phosphorus from urine. We may well have to start recycling phosphorus from our urine on Earth as easily accessible phosphorus sources dwindle. Whether it is done at the sewage farm or more locally is a design and equipment choice. Public, even domestic, urinals may be a good place to start.

      As the old saying goes, “Where there’s muck, there’s brass”.

  • Michael February 7, 2023, 4:36

    Interestingly the maintenance of Earths field is around a megawatt and the contained energy is around 3 exp 16 Joules. We need something much smaller maybe a 1/1000 th than this so its not such a mega project. So smallish superconductors in a cryogenically cooled large circular tube using a few megawatt generators should power up a protective field in a year or less over most if not all of the planet.


Leave a Comment