As we plan longer missions to space, the moon, Mars, and beyond, we’ll need a way to keep our astronauts fed when they can’t get resupply packages from Earth. That means figuring out how to grow food in space.
Prepackaged Meals Won’t Cut It for Long Missions
Presently, most of the food astronauts eat in space comes from Earth. NASA prepares and packages the food its astronauts aboard the International Space Station (ISS) consume at the Space Foods Systems Laboratory at Johnson Space Center and delivers it via resupply vehicles sent to space every 40–45 days.
This system works because of the relatively short distance between the ISS and Earth, but for further and longer missions, it just won’t cut it. When we eventually embark on our journey to Mars, we won’t have the luxury of regular resupply shipments from Earth, and we can’t simply carry all the food we’ll ever need because of weight limitations. Not to mention, the vitamins in prepackaged food tend to break down over time, and this could lead to deficiencies which could pose a risk to astronauts’ health.
It seems pretty clear that if we’re going to embark on a grand space adventure, we’ll need to learn how to grow our own food in space.
The Problem With Growing Plants in Space
On Earth, armed with some soil, seeds, water, and sunlight, even a certified black thumb like myself can get a plant to sprout—at least for a couple of days. In space, it’s a lot trickier to get anything to grow.
There’s no gravity in space, and that immediately throws a wrench into things. You can’t grow plants in a regular planter like you would on Earth. Trying would result in the soil breaking apart and getting in everything from the equipment to your eyes and mouth.
Water also behaves very differently in zero gravity than it does on Earth. It clumps together and sticks to surfaces, which is bad for plants because it makes water distribution very difficult. The water might float away from the roots causing the plant to wilt and die, or it might latch onto the roots, and essentially overwater them, causing the plant to drown.
Getting enough sunlight is also a bit tricky in space. You’d need a lot of windows on a spacecraft to support a reasonably sized garden, which is not only expensive, but risky because of space junk. Even if you did manage it, you still might not be able to get enough sunlight if you are on a mission that takes you further away from our sun. For example, once you’re out near the orbit of Mars, you only get about half the light you do in Earth orbit.
Then there’s the problem of space (pun intended). Unlike farming on Earth, where space is abundant, any produce grown on spacecraft must be done as efficiently as possible to maximize the limited real estate.
Inventive Ways NASA Is Growing Food in Space
Considering all the challenges associated with growing plants in space, NASA had to develop new technologies specifically adapted for growing food in space. There are three of note: The Vegetable Production System, the Advanced Plant Habitat, and The Biological Research in Canisters.
The Vegetable Production System
The Vegetable Production System, or Veggie as it is affectionately known, is a garden aboard the ISS designed to help NASA study the growth of plants in microgravity and provide the occasional fresh food for astronauts. Veggie is about the size of a carry-on luggage and can hold about 6 plants. There are currently two units aboard the ISS, and they will probably feature in whatever spacecraft replaces the ISS when it is eventually deorbited.
Veggie solves the problem of growing plants in space by using plant pillows to grow crops. These pillows are small packets that contain substrate, fertilizer, and germination wicks. Seeds are placed in the wick and water is periodically injected into the pillow. Water and nutrients flow up the wick to the seed, and LED banks set above the plants simulate sunlight, allowing the plants to germinate and grow. Veggie has successfully grown all sorts of plants including lettuce, cabbage, and, famously, Zinnia flowers.
The Advanced Plant Habitat
The Advanced Plant Habitat (APH) is another growth chamber aboard the ISS, but unlike Veggie, the APH is fully enclosed and automated. It automatically adjusts the temperature, oxygen content, moisture levels, light, and other parameters to what’s ideal for the plant it’s growing. It also has cameras and over 180 sensors that send real-time information about the plants’ growth to a team at the Kennedy Space Center.
The ACPH is mainly used for plant research. When the harvest is ready, the crew collect samples, then freeze or chemically fix them, before sending them back to Earth where they can be studied so that scientists can understand the impact of space on their growth.
Biological Research in Canisters
The BRIC is a facility used to study the effect of space on small organisms. The latest version, called the BRIC-LED, is expanding to grow tiny plants in space.
The hardware is still in the works, but it is hoped that the system will tell us more about how space affects plant genes and what we will need to do to make plants better equipped to survive in space.
The Next Step: Growing Plants on the Moon
So far, our gardening adventures in space have taken place aboard spacecraft using resources brought from Earth. But if we’re to be true space explorers, we’ll need to be able to use the resources available on-site to grow our food when we travel to other surfaces. Think greenhouses on the moon, Mars, and wherever else we decide to travel.
To this end, there have been experiments to see if we can grow plants on the moon, and in 2022, scientists at the University of Florida reported that they had successfully grown plants in lunar soil collected on previous Apollo missions.
The plants grown in the lunar soil were not as healthy looking as the control group, and when the scientists ground them up to look at their genes they found that they showed more signs of oxidative stress. But the discovery was still really important because it showed us how plants behave in lunar soil. Now that we know that, we can account for it when we’re preparing the soil for farming, and even alter our plants to grow better in it.
Growing plants on the moon will also give us the experience we need for farming on Mars and beyond. Already, there is promising evidence that a space garden on Mars is feasible. Researchers at Wageningen University and Research in the Netherlands succeeded in growing crops in soil that is a near physical and chemical match to actual Martian soil.
If we’re to have any hope of establishing colonies on Mars or embarking on long-term space missions, we’ll need food to support our astronauts. That means that space farming will need to improve by leaps and bounds. Growing plants in environments that have been barren for millions of years is no small task, but the research is promising, and who knows, maybe in a couple of decades astronauts in space will be completely self-sufficient for their dietary needs.
