Space Food – How Will We Feed Humanity’s Next Wave of Pioneers?

A New Type Of Space Exploration

After several decades of stagnation following the Moon landing, a new space race is heating up. The trigger was SpaceX's extraordinary success in creating a reusable rocket, cutting the launch cost to orbit by an order of magnitude. With the latest launch vehicle, Starship, getting tested, the costs should decrease even more.

Source: Visual Capitalist

SpaceX may be the most impressive space company, but many are on its heels – including various Chinese rocket companies, both private and state-funded.

Simultaneously, NASA and its partners plan to return to the Moon and establish a permanent base there; China and Russia also have similar ambitions. In the next decade, SpaceX intends to see the first men walk on Mars.

So, it is almost a given that we will see many more astronauts in the upcoming decades than since the golden age of space exploration. Contrary to the 1960s, they will be living in space in distant habitats, not just traveling for a few days to the Moon or staying in low Earth orbit in space stations.

This means more people, further away, and in the case of Mars, months of travel away.  All this results in a need to supply them with extra expensive consumables. This skews the economics of supplying the astronauts toward producing what they need on-site. 3D printing will likely play a big role in providing spare parts. And food will need to be at least partially grown on-site.

Besides costs, growing fresh food on site will also help keep the astronauts healthy by providing high-quality C vitamins and antioxidant-rich foods useful for reducing the danger of radiation from cosmic rays and sun storms.

Space Food Prototypes

This is not a new concept, and NASA and other space agencies have been investigating the ideas for several decades. Still, the lack of space on the ISS means that for now, only the pilot project and prototype have been tested, and there are no current plans to produce a serious amount of food in space.

Tested Concept #1: Aeroponics Plant Cultivation

By growing plants without soil or water, aeroponics is a method that seems uniquely fit for weightless conditions like space stations, where liquids and dust are serious issues that can cause shortcuts and fires. You can read more about how aeroponics works and how it is already used on Earth in our article “Aeroponics – Everything You Need to Know”.

Aeroponics is especially efficient at growing fresh products in a record time and with limited space, making it ideal for the cramped conditions of a spaceship to Mars or an orbiting space station.

It can also grow very energy-dense root crops, like potatoes, which are easy to eat without too complex cooking, contrary to cereals.

A prototype has already been tested in the ISS under the eXposed Root On-Orbit Test System (XROOTS) tech demo program.

Source: NASA

Similar systems could grow fresh products for astronauts on long travels, like the 6-18 months to Mars (depending on the propulsion system). These could include the previously tested Veggie (Vegetable Production System), Veggie PONDS, and Plant Habitat-04 (PH-04), which has successfully grown a variety of plants, including three types of lettuce, Chinese cabbage, mizuna mustard, red Russian kale, zinnia flowers, wheat, and peppers.

Tested Concept #2: Microorganisms In Canisters

The Biological Research in Canisters (BRIC) was a program to study the effects of space on organisms small enough to grow in petri dishes, such as yeast and microbes. But such a growing method would steal energy-rich substrates from Earth to be turned into anything edible.

An updated version, BRIC-LED, is the latest version, which uses added light-emitting diodes (LEDs) to support biology, such as plants, mosses, algae, and cyanobacteria that need light to make their food. Solar panels or nuclear reactors could power such LED lamps (similar to the ones used in aeroponics) and allow for on-site food cultivation.

Tested Concept #3: Inflatable Space Greenhouses

NASA has also developed the concept of inflatable hydroponics greenhouses, with an 18-foot-long, 7-foot-wide, 3-inch-diameter prototype tested by the University of Arizona's Controlled Environment Agriculture Center.

Source: Inside Hook

The inflatable greenhouse function follows the principle of hydroponics, something you can learn in our dedicated article “Hydroponics – Everything You Need to Know”.

For the colony's initial steps, foldable or inflatable greenhouses would probably be a good option to save on mass and space in the transport ships.

Future Space Food Systems

There is a need to distinguish the question of growing food in space depending on the environment, with the 3 main possible situations being space stations/spaceships, Moon Bases, and Mars bases.

This creates unique constraints that will shape the possibility for food systems in each environment differently.

Orbit & Deep Space

Because of the space, but also weight constraints (a heavier ship would waste fuel), spaceships and space stations are unlikely to grow all their food. More likely, the crew will resupply when in the orbit of Earth. They could, however, be growing a limited amount of fresh food like leafy greens or microalgae.

Microalgae would be especially interesting if it turns out that the best way to shield a ship's crew traveling to Mars is a thick layer of water (some estimates judge that it would require a 1-meter-deep layer of water to protect the crew against cosmic rays and temporary sun storms).

So we could see every spaceship and space station orbiting Mars equipped with a radiation shelter room using a lot of water. It would then make sense to use the water to grow food as well.

Such systems are already well understood and used for lab experiments, and projects like BRIC-LED show how to adapt them to space & weightlessness.

Source: MDPI

As a bonus, the limited available air also requires extensive recycling, which oxygen-producing plants or algae could help contribute.

Moon Bases

Thanks to the possibility of bringing prefab modules or material for 3D printing from nearby Earth, space is much less of a concern. The Moon is also expected to have some water available on site, so cultivation would not require bringing tons of heavy liquids on top of fertilizers to start the cultivation in orbit.

This makes the idea of a fully autonomous Moon base, at least as long as the population is in the hundreds or thousands, viable.

This would also prove to be a great testing ground for all food production methods later required on Mars. If, somehow, an entire crop fails, getting emergency food resupply from Earth 3-days away would not be an issue.

However, the moon is unique in some respects. Night can last very long, making the idea of domed greenhouses relying on natural light impossible. For the same reason, nuclear reactors will likely need to supply power instead of solar panels.

It also has absolutely no atmosphere, reducing the possibility of getting free CO2 and balancing out surplus oxygen. So, every Moon food system will have to be a perfectly closed loop.

However, the Moon has gravity (1/6th of Earth), making hydroponics or even aquaponics a viable option to provide crops and even meat to astronauts in a less labor-intensive way than aeroponics. You can read how aquaponics can mix aquaculture and hydroponics in the same system in our article “Aquaponics—Everything You Need to Know.”

Moon Agriculture scenarios

Fresh products will likely be cultivated locally to provide a vitamin and moral boost to the astronauts.

It is not clear yet what the bulk of calories (proteins and carbs) will be. Ultimately, economics will decide whether only a part or all of the food of the Moon's residents will be produced on-site.

• If it is cheaper to bring it from Earth in bulk than building massive cultivation facilities, only fresh products will be cultivated on the Moon.
• Alternatively, if it turns out to be prohibitively expensive, semi-automated aeroponics potatoes, beans, and grains farms might be the way to reduce the operation costs of the Moon bases.

Mars Bases

Mars is tremendously far from Earth. Producing food locally will be both an economic necessity and a security risk solution.

This was brilliantly illustrated in Andy Weir's book The Martian, later adapted into a movie with Matt Damon, where a stranded astronaut resorts to improvised potato farming to survive. And the greatest danger he faces is not radiation, lack of air, or cold, but starvation.

Source: Modern Farmer

The goal of Martian bases is also different than that of the Moon. The ultimate goal is full-fledged colonization. So if a population of a few tens of hundreds of astronauts could be sustained at great cost from Earth, tens of thousands or millions never could.

This means that Mars will need to be fully autonomous in food production.

The same types of cultivation as on the Moon are possible: large-scale hydroponics or aquaponics. But because Mars has an atmosphere and a day lasting almost exactly 24 hours, it is also possible to build surface greenhouses and collect the CO2 plants need from the thin atmosphere while mining ice for water.

It is also very likely that Mars has, like Earth, local deposits of phosphorus, nitrogen, and potassium that can be mined and are required for intensive farming.

These greenhouses need to be warmed, fertilized, and airtight, but they will provide a much more efficient, resilient, and less energy-demanding farming method.

Making Mars Fertile

It might also benefit Martian agriculture to cultivate directly in the soil, requiring less machinery than hydroponics. This would free equipment, labor, and resources for other uses.

One issue to solve is that the Martian soil (regolith) is rich in hydrogen peroxide (H2O2). This highly oxidative chemical can kill plants and bacteria, especially at the concentrations found on Mars.

Luckily, peroxide can also be used to produce oxygen. This has been demonstrated thanks to the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) tested on the Perseverance rover. So we can easily imagine future missions “mining” regolith to create oxygen for the astronauts, as well as to be used for rocket fuels.

And then using this processed, peroxide-free regolith turns it into fertile soil for the greenhouses.

Another option could be to create artificial ponds, maybe over small craters, where algae, freshwater shells, and fishes could grow “wild” with minimal maintenance, by just keeping the greenhouse domes warm and airtight.

Other Space Food Technologies

So far, we have mostly discussed growing food through aeroponics, hydroponics, and aquaponics, as well as sealed greenhouses. But other options might also be explored. One of these is synthetic food.

In 2021, Chinese scientists developed the first method for the artificial, cell-free synthesis of starch (C6H10O5) from CO2. Considering starch is the main caloric component of grains like rice, corn, and wheat, this is worth paying attention to. And for that matter, Mars's atmosphere is 95% CO2.

Source: Science.org

The system used a zirconium-based catalyst and achieved an ~8.5-fold higher synthesis rate than starch synthesis in maize.

So, maybe we could imagine an integrated and automatized module that synthesizes starch continuously, literally from thin air. This could provide the bulk of calories required for animal feed or human staples, with traditional farming focusing only on high-quality and vitamin-rich foods instead.

In any case, we can imagine such systems operating autonomously before any astronaut even lands on Mars, to create on-site and ahead of a landing a massive stash of calories to avoid a scenario like in The Martian.

Other options exist as well, notably other types of synthetic food, including proteins (see below Solar Foods's Solein), or lab-grown meat, or meat substitutes like a fungi-based meat tested in the ISS in 2022, produced by the company Nature’s Fynd.

Space Food Companies

1. Aleph Farms

Aleph Farm achieved the growth of the first cultivated meat (steak) experiment in microgravity aboard the ISS during the Rakia Mission. As any form of husbandry may be impossible in the initial stages of space colonization, meat will probably only be produced through this type of method.

Having already tested the process in microgravity, Aleph Farms is ahead of most other lab-grown meat companies in the space food market. Israel approved its meat products for commercialization in 2024.

The company is also working on producing slaughter-free collagen, a key ingredient in many food, cosmetics, and medical products.

2. Solar Foods

This company is looking to “produce food out of thin air”. It raised €8 Million at the end of 2023 to pursue this goal.

The concept is to use electricity to break water into oxygen and hydrogen and use the hydrogen, as well as atmospheric CO2 and mineral nutrients, to feed microorganisms that will produce a dry powder made of 70% protein.

Commercialized under the brand Solein, this protein source containing all 9 essential amino acids can be incorporated into other ingredients to make a very dense nutrition source.

Source: Solar Foods

The company is explicitly targeting the space exploration market. Still, it also envisions that in the long term, it could revolutionize food production on Earth as well, as it offers a protein source that converts energy into protein very efficiently.

“We feed the microbe like you would feed a plant, but instead of watering and fertilizing it, we use mere air and electricity. With our current process, this is 20x more efficient than photosynthesis (and 200 times more than meat).”

Solar Foods received the first novel food regulatory approval for Solein from the Singapore Food Agency (SFA) in September 2022.

Adapting for Space Food

Throughout history, food cultivation and nutrition have been forced to adapt to their environment. This was true for the farmers cultivating rice on terraces in Asia to the Inuit people relying almost exclusively on a meat-based diet.

Space will be no different, although it will have the unique feature of having absolutely no natural fertility or wild ecosystem. This means that any space-based food production will entirely depend on machines or ecosystems designed from scratch by humans.

Highly compact and efficient systems like synthetic food or aeroponics will likely dominate in the most hostile environment, like in spaceships or on the air-less Moon.

On planets like Mars, something closer to regular farming might be possible. Natural sunlight would work together with LED lights and ultra-efficient farming systems inside airtight, heated greenhouses.

Like often with space technologies, this concept could also have a massive impact on Earth. Our everyday lives already use technology that was initially developed for space, like water filters, microchips, cordless tools, scratch-resistant lenses, or smoke detectors.

It is possible that in a few decades, synthetic starch and protein, automatized aeroponics farms, and ultra-efficient greenhouses to deploy in desert regions and the Arctic will be added to this list.