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Space Agriculture

Growing Food in Zero Gravity, 400km Above Earth

Someone grew potatoes on the International Space Station and Reddit awarded 79K upvotes. Here's the science, the history, and why farming in orbit is the key to colonizing Mars.

By The Numbers

50+

Plant species grown on the ISS

0 g

Gravity in orbital farming

Sunrises per day in orbit

400km

Altitude of the highest farm

A Brief History of Space Farming

From Soviet experiments to ISS potatoes — 44 years of growing food off-planet.

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1982

First Seeds in Space

Arabidopsis plants complete a full growth cycle aboard the Soviet Salyut 7 station — the first time a plant flowers and produces seeds in orbit. Proof of concept: life can reproduce off-planet.

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1997

Wheat on Mir

Super Dwarf wheat grows from seed to seed aboard the Mir space station, completing multiple generations in orbit. Scientists confirm that grain crops can potentially sustain a space-faring civilization.

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2014

Veggie System Arrives on ISS

NASA installs Veggie — a plant growth chamber using red, blue, and green LEDs — on the International Space Station. The era of systematic space farming begins. It folds flat to the size of a carry-on suitcase.

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2015

First Space Lettuce Eaten

Astronauts Scott Kelly and Kjell Lindgren eat red romaine lettuce grown in the Veggie system. First food grown and consumed in space. Kelly's review: "That's awesome." The entire internet agreed.

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2016

Zinnia Flowers Bloom

Astronaut Scott Kelly grows the first flower in space — zinnia plants that struggled with mold and drought before finally blooming. Kelly became an improvisational space gardener, overriding ground control watering schedules to save them.

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2021

Chili Peppers in Orbit

NASA's Plant Habitat-04 experiment grows Hatch chile peppers on the ISS. Astronauts make space tacos. The peppers took 137 days from seed to harvest — the longest plant experiment on the station at the time.

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2026

Potatoes on the ISS

The moment that broke Reddit: potatoes successfully grown aboard the ISS, earning 79K upvotes on r/space. Potatoes are the first major calorie-dense staple crop grown in orbit — a critical milestone for long-duration missions.

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2030s+

Mars Greenhouses

The next frontier: pressurized inflatable greenhouses on Mars, using regolith-based soil and water extracted from subsurface ice. Every experiment on the ISS is a rehearsal for the day humans farm another planet.

The Science of Growing Plants in Space

No soil, no gravity, no rain. Here's how it works.

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LED Grow Lights

The ISS orbits Earth every 90 minutes, creating 16 sunrises and sunsets per day. Plants can't handle that chaos. NASA's Veggie system uses precisely tuned red, blue, and green LEDs to simulate a stable photoperiod. Red and blue wavelengths drive photosynthesis. Green light was added because all-purple plants looked dead and astronauts found it psychologically unsettling.

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Water in Microgravity

Water doesn't flow downward in space — it forms floating blobs. Space farming uses capillary action and wicking materials to deliver water directly to root zones. Plants grow in 'pillows' — sealed bags of clay-based growth medium with slow-release fertilizer. Controlled wicking pulls water to the roots without drowning them. Too much water and roots suffocate. Too little and they desiccate. The margin is razor thin.

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Microgravity Growth

On Earth, roots grow down (gravitropism) and stems grow up. In space, plants lose this compass. Roots grow in every direction, sometimes curling back on themselves. Plants rely on phototropism — growing toward light — as their primary orientation cue. Interestingly, some studies show plants grow faster in microgravity because they don't spend energy fighting gravity. Their cell walls are thinner and stems are more flexible.

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Controlled Atmosphere

The ISS maintains CO2 levels around 2,000-5,000 ppm — 5 to 12 times higher than Earth's atmosphere. This is actually beneficial for photosynthesis. Plants convert that CO2 into oxygen, which astronauts breathe. A functioning space greenhouse isn't just a food source — it's part of the life support system. Every lettuce leaf is also an oxygen factory.

Why Potatoes?

Mark Watney was onto something.

“They say once you grow crops somewhere, you have officially colonized it. So, technically, I colonized Mars.”

— Mark Watney, The Martian (Andy Weir, 2011)

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Calorie Density

Potatoes produce more calories per square meter than any other major crop. A single square meter of potato plants can yield 5,600 calories — nearly twice the output of rice or wheat in the same space. When your growing area is a pressurized module on Mars, every square centimeter counts.

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Nutritional Completeness

Potatoes provide carbohydrates, protein, vitamin C, potassium, vitamin B6, and fiber. You can survive on almost nothing but potatoes and a fat source for extended periods. The Irish proved this for centuries (until they also proved the risk of monoculture).

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Grows in Poor Soil

Potatoes tolerate acidic, rocky, nutrient-poor conditions that would kill most crops. This matters for Mars, where the 'soil' is iron-oxide-rich regolith with perchlorates and no organic matter. Potatoes are the most likely crop to survive in amended Martian dirt.

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Vegetative Reproduction

Potatoes don't need seeds — they grow from tuber cuttings. You harvest a potato, cut it into pieces with 'eyes,' and plant them. Each piece grows a new plant. This means your harvest IS your seed stock. On a Mars colony, that self-replicating efficiency is the difference between sustainability and resupply dependency.

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Proven in Extreme Conditions

In 2016, the International Potato Center (CIP) in Lima, Peru grew potatoes in a sealed CubeSat simulator mimicking Martian atmospheric conditions — sub-zero temperatures, high CO2, low pressure. The potatoes grew. They weren't thriving, but they grew. On Mars, 'not dead' is a win.

What Farming on Mars Would Actually Look Like

Forget rolling fields. Think sealed greenhouses and engineering miracles.

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Pressurized Greenhouses

Mars atmospheric pressure is 0.6% of Earth's. An unprotected human would lose consciousness in 15 seconds. Plants need pressure too — without it, water boils at body temperature and cell structures collapse. Mars greenhouses must be inflatable, transparent, pressurized domes maintaining at least 30-50 kPa internally. Every greenhouse is a spacecraft that doesn't fly.

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Regolith Soil Engineering

Mars 'soil' isn't soil — it's crushed rock with zero organic content and toxic perchlorate salts. Before anything can grow, regolith must be washed to remove perchlorates, amended with nitrogen-fixing bacteria, composted with organic waste from the crew, and gradually built into something resembling living soil over years. The first Mars farmers will be soil engineers first and botanists second.

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Water from Ice

Mars has enormous subsurface ice deposits, particularly near the poles and in mid-latitude glaciers. A farming colony would extract water by drilling into ice deposits, heating and filtering the meltwater, and recycling every drop through a closed-loop system. Nothing is wasted. A Mars greenhouse would recapture transpired water from the air and run it back through the roots. Water efficiency would make even the most advanced Earth drip irrigation look wasteful.

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Light Supplementation

Mars receives about 43% of Earth's sunlight due to its greater distance from the Sun. Martian dust storms can reduce surface light by 99% for weeks. Solar-powered LED arrays would supplement natural light, with nuclear power (likely a small fission reactor) as backup during storms. The combination of filtered Martian sunlight through transparent dome panels plus targeted LED supplementation gives plants the photosynthetically active radiation they need.

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Closed-Loop Life Support

A Mars farm isn't just food production — it's half of the life support system. Plants absorb CO2 and release O2. Crew absorb O2 and release CO2. Human waste provides nitrogen and phosphorus for plants. Plant waste feeds composting systems. A Mars colony greenhouse is a miniature biosphere where farming and breathing are the same system. Break the loop and everyone dies.

The Investment Case

Space farming technology is already a terrestrial industry.

Every technology developed for growing food in space has a direct commercial application on Earth. The same LED grow light systems, hydroponic nutrient delivery, and controlled environment agriculture (CEA) techniques that NASA uses on the ISS are the backbone of a terrestrial industry projected to exceed $30 billion by 2030.

The thesis is straightforward: as arable land shrinks, water becomes scarcer, and populations grow, the ability to grow food in sealed, controlled environments — indoors, underground, in deserts, or in orbit — goes from niche to necessity.

Vertical Farming

Indoor farms stacked floor-to-floor using LED lights and hydroponics. 95% less water than traditional farming. Year-round production regardless of climate. Companies like AeroFarms, Plenty, and Bowery are scaling rapidly.

$12B+ market by 2028

Agricultural LED Lighting

The same red/blue spectrum LEDs that NASA developed for Veggie are now the standard for indoor farming. Tunable spectrum, energy efficient, precisely targeted wavelengths. The technology went from space station to commercial greenhouse in under a decade.

$8B+ market by 2028

Precision Nutrient Systems

Automated hydroponic and aeroponic systems that deliver exact nutrient concentrations to plant roots. Originally designed for space constraints where soil isn't an option. Now the fastest-growing segment of commercial agriculture technology.

$5B+ market by 2028

Glen's take: The best space investments aren't the rockets — they're the life support systems. The companies building controlled environment agriculture technology have customers whether or not we get to Mars. That's the kind of asymmetric bet I like: if Mars happens, they win big. If it doesn't, they're still feeding people. Either way, the technology gets built.

Glen's Take

Growing a potato in space sounds like a novelty. It isn't. It's one of the most consequential agricultural achievements in human history.

Every calorie grown off-planet is proof that human survival doesn't have a ceiling. We aren't locked to this rock. We can feed ourselves anywhere there's light, water, and a sealed container. That changes the entire calculus of space exploration from “how much food can we bring” to “how much food can we grow.”

The first person to eat a potato on Mars will be standing on the shoulders of every astronaut who nursed a lettuce seedling under purple LEDs in a tin can 400 kilometers above Earth. And the 79,000 Redditors who upvoted it? They knew it mattered. They just might not have known why.

Frequently Asked Questions

Can plants grow without gravity?

Yes. Plants don't need gravity to grow — they need light, water, nutrients, and CO2. In microgravity, plants lose their usual sense of 'up' and 'down' (gravitropism), but they still grow toward light (phototropism). Roots grow in all directions without gravity, which is why space farming uses specially designed pillow-like containers with wicking systems to deliver water directly to the root zone.

What plants have been grown on the International Space Station?

Over 50 plant species have been grown on the ISS, including red romaine lettuce, mizuna mustard greens, Chinese cabbage, radishes, zinnia flowers, Hatch chile peppers, cotton, dwarf wheat, tomatoes, and most recently potatoes. NASA's Veggie and Advanced Plant Habitat systems have been the primary growth chambers since 2014.

Why are potatoes important for space farming?

Potatoes are uniquely suited for space agriculture because they're one of the most calorie-dense crops per unit of growing area, they provide carbohydrates, vitamin C, potassium, and fiber, they can grow in poor soil conditions (relevant for Mars regolith), and they reproduce vegetatively from tuber cuttings rather than seeds. Andy Weir wasn't just writing fiction in The Martian — potatoes really are the ideal Mars crop.

How would farming on Mars actually work?

Mars farming would require pressurized greenhouses (Mars atmospheric pressure is less than 1% of Earth's), supplemental LED lighting (Mars gets about 43% of Earth's sunlight), water extraction from subsurface ice deposits, soil created from Mars regolith mixed with organic matter and nutrients, and careful atmospheric management for CO2/O2 balance. The entire system would essentially be a sealed, climate-controlled biosphere.

Is space agriculture a good investment opportunity?

The controlled environment agriculture (CEA) market — which includes vertical farming, LED grow systems, and hydroponic/aeroponic technology — is projected to reach $30+ billion by 2030. The same technologies that grow lettuce on the ISS are already being commercialized on Earth. Companies in vertical farming, agricultural LED lighting, and precision nutrient delivery systems are the terrestrial beneficiaries of space agriculture research.

Know someone who thinks space farming is science fiction?

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