Say you want to build a base at a place where conventional food deliveries from Earth would be very expensive. What will be the most energy-efficient food production process that could feed humans, both at the beginning of the mission and in the long term (years)? Will people grow calory-rich plant(s) first and try to transition to a more complicated ecosystem later as that may have better energy efficiency due to more sophisticated biological cycles (plants, insects, waste recycling, etc.)? Will the more complex ecosystems better use the nutrients and also provide a more diverse range of foods to humans? Or, will it be easier to "brute force" the food production with enough power (solar, etc.) as I don't expect that creating a stable ecosystem will be simple?

There is a very interesting question on the possible power requirements for food production where answers deal with corn but I actually would not expect corn to have a high "input energy"/"produced calories" ratio since the higher plants may be less efficient (at least in oxygen production).

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    $\begingroup$ Nobody knows. Sustainable closed loop human life support away from the Earth is Technology Readiness Level (TRL) 2, maybe 3. It has not been done. $\endgroup$ Jan 20, 2021 at 14:48
  • $\begingroup$ Ok. I assume some experiments have been done on Earth, right? Like the Biosphere 2? What is the current state-of-the art on these? $\endgroup$
    – Kozuch
    Jan 20, 2021 at 14:51
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    $\begingroup$ Biosphere 2 was an abject failure. It was a lesson in how not to do it. For example, they learned that using uncured concrete was a bad idea. $\endgroup$ Jan 20, 2021 at 14:52
  • $\begingroup$ Wikipedia says Biosphere 2 was a success (the only 2 closed-system limited-timespan projects). We should do something smaller and more up-to-date. $\endgroup$
    – Kozuch
    Jan 20, 2021 at 17:16
  • $\begingroup$ Are you interested in the plants that convert the most light energy into calories or the most energy efficient way of feeding humans? $\endgroup$
    – Slarty
    Dec 22, 2023 at 8:21

3 Answers 3


To answer this question, we first need to consider what is needed to sustain people in space. If we assume that we can't limit our crew to keto eaters, then (according to a presentation by Bryce Meyer given in the Space Settlement session of the International Space Development Conference in 2023) some examples of ideal foods for space travel will include:

  • Bell peppers
  • Rice
  • Vegan, min processing (e.g. roasting peanuts, etc.)
  • Vegan, heavy processing but no peanuts (e.g. includes fermentation)
  • Vegan, processed foods and peanuts
  • Seafood proteins (kosher, non-kosher, etc.)
  • Insect proteins
  • Birds (kosher, non-kosher, etc.)
  • Rabbits

These plants and animals reproduce quickly, which is good for efficiency. On the other hand, almonds, cashews, pecans, and larger livestock do not reproduce as quickly, and are therefore examples of foods that would be inefficient - at least in the short term.

Plants in space provide not only food, but also oxygen generation, carbon dioxide removal, and support mental health. Duckweed, for example, can even be used for purifying water. When determining efficiency, it's advisable to consider all of the ways plants are beneficial when selecting the right mix of flora for a base. Multi-purpose plants may be more efficient overall than plants that are very good at doing just one thing.

The resiliency of your ecosystem is also important. For example, algae are size-efficient due to doubling time and photobioreactor size; however, the tank may be more susceptible to failure than a robust plant-based crop. (Note: This scenario was used as a plot device in the 2021 Movie Stowaway.)

On Mars, it may be more efficient to grow plants in lava tubes under artificial lighting than to use greenhouses, even after the cost and efficiencies of solar panels and LEDs are factored in. But, in space, crop selections may be influenced by the plant's susceptibility to oxidative stress induced by space radiation (Oxidative stress is defined as excess production of reactive oxygen species (ROS) relative to antioxidant defense.)

There are lots of factors that go into engineering a biosphere and there is lots of active research in this exciting field. Many researchers have theories on what the best solutions might be, and several experiments are underway at universities, such as the University of Arizona, to try to verify these theories. There are even some startups, such as InterstellarLab, that are attempting to commercialize solutions to these kinds of problems.

(Note: The author is not affiliated with UofA or InterstellarLab.)

  • $\begingroup$ Interesting information, although the question seems to be specifically asking only about the energy required to create the light needed to produce different types of foods. The OP included a link to a question about the total light energy needed for food production. I don't think they are including other energy factors such as the energy needed to harvest, create fertilizer, etc., or overall efficiency, which would be a broader question. Plants and animals that quickly multiply might require less light energy per calorie produced, but I think they are looking for some quantification on that. $\endgroup$ Dec 21, 2023 at 16:30
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    $\begingroup$ He linked to another question about energy requirements, but it's not a repeat. This question was not "only about the energy required to create the light needed to produce different types of foods", it is a more open-ended question about what the "Most energy efficient food production" process is. For example, more traditional versus more synthetic. $\endgroup$
    – phil1008
    Dec 22, 2023 at 5:40
  • $\begingroup$ phil1008 - If only reading the title, "food production" is a broad term. But in the question summary the question is clarified, "What will be the most energy efficient food that could feed humans …. in the beginning of the mission?". They question if calorie rich foods will be grown first prior to developing a complex ecosystem, or else accept that a complex ecosystem is too difficult and instead prioritize providing enough "power (solar etc.)". They link to a question "Power to grow food per person", and then speculate about corn's "input energy/produced calories ratio" $\endgroup$ Dec 22, 2023 at 15:22
  • $\begingroup$ I see what you're saying. His next sentence is "Will people grow calory-rich plant(s) first and try to transition to a more complicated ecosystem later..." So, this points in the direction of "food production" as the main topic. "Which food(s)" might be considered a sub-topic but not the primary subject of this question. $\endgroup$
    – phil1008
    Dec 28, 2023 at 1:22
  • $\begingroup$ phil1008 - they only mentioned complicated ecosystem in the context of "later", and they indicated the possibility that it could be much later since it could wind up being extremely difficult. Everything else they said was about types of food and the energy required to produce different types of food. And in the one link they provided they only seemed to be interested in what it said about the energy requirements per calorie for corn, but then indicated that they think corn is not necessarily a representative example, inferring that they are looking for the energy needs of other types of food. $\endgroup$ Dec 28, 2023 at 12:46

Human nutrition is a very complex subject And the dynamics of food production on Mars will take decades to be developed and optimized. So it is not possible to do anything other than provide a few pointers. Being calorie rich is just a small part of ensuring human health. Many minerals and vitamins are needed as well as proteins that include all required amino acids and fat including the essential fatty acids.

Food production won’t be the primary issue at least initially. First will be the politics around thousands of good well paid technical jobs, votes and monetary costs here on Earth. After that assuming there is the political will the next two things would be power (nuclear and solar) and a reliable ground proven water source capable of providing thousands of tonnes of water / year for an extended period.

After all of that yes food production from local resources would become a priority and there would probably be a range of technology demonstration units followed by small scale vegetable and perhaps grain production. But initial production would be unlikely to meet all of the crews needs. So the initial set up can’t be fully closed (excess wastes).

Over time (probably decades) more systems and modules would be introduced to help reduce the reliance on imports. Perhaps live fish might be included and insects as well as fermented products and more.

Ultimately the types of plants used would depend on experiments on Mars and what works best. In the more distant future there might be attempts to introduce a full ecosystem and integrate food production with air purification and water recycling, but I predict it will take a very long time to optimize.

Final thoughts the speed of development in food production on Mars would depend on how successful it was, on what emphasis was placed on reducing costs and what emphasis was placed on growing the size of the base v making the existing base more self sufficient. Food of some sort (chocolate etc) will probably continue to be sent from Earth almost indefinitely.

  • $\begingroup$ "Food production won’t be the primary issue at least initially. First will be the politics around thousands of good well paid technical jobs, votes and monetary costs here on Earth." The question is asking what foods are energy efficient in terms of the amount of light they require, keying off a previous question about the overall power needed to produce light for food. Do you have an answer to that question? Also most people would not include "salad" in a list of food types. Was this answer written by a human? $\endgroup$ Dec 21, 2023 at 12:20
  • $\begingroup$ Quick check - yes human - will change the wording. I think some clarification might be needed on the question... $\endgroup$
    – Slarty
    Dec 22, 2023 at 8:11

Highly efficient food production can be unsafe and subject to blight and crop failiure, mixed crops complement each other for maximized resource use and protect each other and provide more food security. Hydroponics is pretty efficient for some crops but it not a source of very good food. If you want to efficiently produce bad food then you can just use chemistry to produce protein, carbs, sugars, even lab meat.

Fish and vegetation are a good known closed biomes to cultivate food, so you can use the fish and water to produce nitrogen and to filter the toxins through microbial maps inside aquaculture, also growing plants in the water.

The bigger a biological system, the more resilient it is to changes in temperature and microbial blooms and other changes.

The best way to keep everything contained on another planet is to dig big tunnels in impermeable rock and guarantee it is impermeable, use it as a large filtration lake for whatever agriculture you would want to do.

As technology advances very sophisticated microbiology and macro ecology strategies can be devised, food production remains the biggest barrier to extended terraforming.

As the rover has proven, it's easier to send an army of robots to do all kinds of things on far away planets because they survive for years in ambient conditions.

For robots are necessary to do nearly everything that a human could do on another planet, efficiently, including digging giant tunnels that humans could live in later, and fabricating buildings.

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    $\begingroup$ This does not really answer the question. Suggest removing the rover and tunnel related bits and look for a source on the fish+plant design, ideally one that gives numbers for needed power inputs, since that is specifically what the question is asking for. $\endgroup$ Dec 21, 2023 at 9:05
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    $\begingroup$ "Volvo food production remains the biggest barrier 2 days that think terraforming is a viable human activity." What does this sentence mean? $\endgroup$ Dec 21, 2023 at 12:09
  • $\begingroup$ ... @gremlinwrangler This question is opinion based because healthy food is a combo of at least 50 major chemicals, 50 minor ones and many trace minerals, the healthy human diet consists of at least 250 major and minor compounds, vitamins, antioxidants, sugars, starches, fibres, and many other types of chemical. I am answering from the perspective of organic food production using biological foods, ecosystems of mixed plants complement each other for resource use and protect each other. volvo- It means that voice recognition is not on 100% and I missde that. There were not volvos. $\endgroup$ Dec 21, 2023 at 15:05
  • $\begingroup$ bandybabboon - the question is not opinion based because it is asking about the energy required to provide the light needed for producing different types of food, which is quantifiable. They did not ask what foods are nutritious, etc. they only mentioned that as they mused about the possible conflict of weighing energy efficiency and nutrition in deciding what to produce, especially when just starting out. This would factor into decisions about what foods to import vs produce on site. $\endgroup$ Dec 21, 2023 at 15:48
  • $\begingroup$ bandybabboon - if I remove the word volvo from the sentence I still don't understand it. $\endgroup$ Dec 21, 2023 at 15:53

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