The Future of Space Travel Could Come Down to This Potato

Luis Felipe Villani Purquerio greets me on the steps of a sun-soaked building, a burst of cantaloupe orange in the radiantly green countryside of southeast Brazil. Purquerio is an agronomist—a plant and soil scientist—at the Instituto Agronômico de Campinas (IAC), one of the oldest agricultural research centers in the world, about two hours away from São Paulo.

Inside, he walks me through the history of the place: Founded in 1887 by Brazil’s last emperor, the institution develops more productive and resilient plant varieties for the country’s farmers. The lobby is decorated with antique illustrations of rambling farmland and open skies, and an assortment of fruits and vegetables—a picturesque rendering of the planet’s bounty.

The delicate images are a world away from the institution’s newest research effort. In the lab rooms beyond, beneath the glow of blue and white bulbs, Purquerio and his students are experimenting with a very different kind of agriculture: How to cultivate crops in outer space, so that future astronauts—future farmers—can grow their own food.

Astronauts already eat quite well, thanks to years of food-science research. But future generations of explorers will require sustainable food sources to supplement their usual freeze-dried, heat-stabilized, and shelf-stable provisions. And the best practices of cosmic farming will need to be devised long before they set off.

Scientists around the world are dreaming up ways to support plant life beyond Earth, and Brazil, with its rich history in agricultural research, is particularly well suited for the work. In 2022, researchers launched a country-wide effort called the Space Farming Brazil Network, the latest addition to this growing field of space agriculture. Purquerio belongs to this new collaboration of agronomists, space scientists, and aerospace engineers from institutions around the country, aimed at preparing crops for a range of otherworldly habitats: a crater rim on the moon, a spaceship gliding through deep space, the sandy, windswept plains of Mars.  “We are studying heat stress, light stress, nutrition stress—because when we go to space, plants will be stressed,” says Purquerio, who runs the indoor-farming laboratory at IAC.

Purquerio and his collaborators hope that their research on extraterrestrial agriculture can also help crop production back on Earth, where Brazil’s farming regions are being tormented by the effects of climate change. A warming planet is its own kind of inhospitable, says Ricardo Lourenço Ogando, an astrophysicist at Centro de Tecnologia da Informação Renato Archer, where researchers are also participating in the project. “We are closer to turning Earth into Mars rather than the other way around," Ogando says.

(These scientists are trying to grow ‘space plants’ in the coldest place on Earth.)

Sowing the Seeds of Space Farming

Astronauts have already farmed in orbit, cultivating greens, rice, radishes, chile peppers, and other crops aboard the International Space Station—mostly for research purposes rather than for regular consumption, with the exception of the occasional salad topping. Future space explorers will need more filling and nutritious options, especially for long-duration journeys, says Alessandra Pereira Fávero, a researcher at Embrapa, Brazil’s agricultural agency, which leads the network along with the Brazilian Space Agency.

The team is focusing on sweet potatoes and chickpeas, a decision made after months of deliberation, which involved ruling out crops that required pollination by bees, for obvious reasons, Fávero says. Neither plant is particularly fussy to grow, she says. They picked chickpeas because they’re good sources of protein, and they went with the purple variant of sweet potato because it’s rich in anthocyanins, a powerful kind of antioxidant. “This is very healthy for people and for the plant,” Fávero says—research has shown that anthocyanin in seeds safeguards them against space radiation. (Brazil also maintains large germplasm banks of both crops, repositories of genetic material that researchers can use to develop new varieties.)

Fávero  hopes that future explorers won’t just pluck sweet-potato leaves and snack on them raw, but actually engage in some real interplanetary cooking, or at least whip up some space hummus.

(What will future astronauts eat in space?)

The future of space snacks will likely involve breeding more robust versions of sweet potatoes and chickpeas with properties best suited for cosmic environments: shorter growth cycles, higher yields, greater nutritional content.

Purquerio and his team plan to cultivate seedlings of sweet potatoes and chickpea indoors without natural dirt and traditional watering. Instead, the plants will grow in a substrate made of coconut fiber instead of soil, and receive nutrient solutions to the root system via artificial irrigation—the same kind of system that astronaut-farmers are bound to utilize. By tweaking artificial light and nutrients, researchers can find out how much stress the crops can withstand without losing their robustness.

Purquerio imagines a bonsai-style system of perpetually flowering sweet potato plants, with leaves always ready to be snipped off. “Leaves are very rich in different kinds of nutrients,” he says.

There’s a preview of space farming in Purquerio’s lab, where shelves are stacked ceiling-high with pots of stout, leafy tomato plants—a potential model for sweet potatoes and chickpeas grown off Earth. The crop is a hybrid that doesn’t reach its typical height but produces larger fruits than usual. “The shorter the plants, the more layers I can have in the lab,” Purquerio says. Small but productive plants would fit nicely in the tight quarters of a space greenhouse, too.

On long-duration space missions, “every resource counts,” says Matheus Kainan, a Ph.D. student on Purquerio’s team who comes from a line of farmers. Space crops will need to make due with fewer reserves than usual. Achieving those adaptations for space purposes “can actually translate afterwards to our needs” on Earth, Kainan says.

A Galactic Granary Could Help Earthly Growers, Too

The study of space crops could help generate strategies for resilience in their Earth-bound counterparts. Purquerio and the other researchers hope that any inventions by the space-farming project will “come directly to the growers” long before any astronauts set off for strange, precarious worlds.

In the 1960s, as Brazil set up its national space program—constructing its first launch site, developing suborbital rockets—it also began a farming expansion that eventually transformed the country from a struggling food importer to an agricultural powerhouse. Today, Brazil has one of the largest space programs in South America, and the country is one of the world’s top producers of major staple crops. But rising global temperatures—as well as deforestation and unsustainable farming practices within the country, which contribute to climate change—threaten growers.

In recent decades, the country has experienced more frequent and severe weather events and more dangerously hot days in the year. Dry seasons have stretched longer, creating water shortages for growing operations and fanning record numbers of wildfires. Extreme heat damages crops, shrinks yields, and encourages the proliferation of disease-causing pests—and it’s grueling and hazardous for farm staff who work outdoors. When the rainy season does arrive, the skies pour with brutal intensity, leading to damaging flooding.

To build a galactic granary that could benefit both earthly and extraterrestrial growers, Augusto Tulmann Neto, a plant-breeding expert at the Center for Nuclear Energy in Agriculture (CENA) at the University of São Paulo’s campus in Piracicaba, is studying how to genetically tweak seeds for survival. On the greenhouse grounds, an hour west of Campinas, Tulmann shows me a tray of young chickpea plants with peach-fuzz leaves in damp soil. They’re different heights, neatly arranged from tallest to shortest, as if an invisible shrinking wand has swept across them, and in a way it has: the seeds of the plants were zapped with gamma rays before being planted, each set exposed to increasingly higher dosages. The process randomly alters their DNA within seconds, introducing random mutations. In the case of these irradiated chickpeas, Tulmann Neto says, “something happened with the hormones that promote growth.”

Such irradiation technology has been in use for decades to induce certain characteristics in crops, such as increased hardiness to droughts and disease, and it could help prepare plants for the celestial wilderness too, Tulmann Neto says. While scientists can’t predict the mutations that may appear in the first round, they can screen future generations grown from the same plants for the traits they want. For chickpeas, that may include flowering earlier than usual, a feature that allows plants in extremely dry conditions to complete their life cycles before heat stress wreaks too much havoc. Crops modified to thrive with the limited water supply on a moon base, Tulmann Neto says, may be even better equipped to endure parched conditions on this planet.

How to Space-Proof Plant Experiments

Last year, the Space Farming Brazil Network dispatched their first crop subjects— sweet-potato plants and chickpea seeds—to the edge of space on a Blue Origin rocket. They were variants from Embrapa’s collection, already enhanced to be more productive and nutritious. (Researchers are still waiting for these samples to arrive in Brazil for study, Fávero says.)

As the project grows, the team’s space-bound setups will undergo trials at the National Institute for Space Research (INPE) in São José dos Campos, which assembles and tests satellites before launch. The laboratory houses several machines that simulate the space environment, giving hardware a preview of the unfathomable cold that awaits them; the largest of these thermal-vacuum chambers is the size of a barn. Here, unassuming doors lead to other cavernous rooms, where the technical infrastructure produces almost magical effects. In the anechoic chamber, the walls are covered with thousands of spiky pieces of foam that expertly absorb sound waves, leaving behind a pure, echoless silence.

Engineers here will help the plant scientists space-proof their experiments, says Adenilson Roberto da Silva, a senior technologist who directs INPE’s space systems division. When a researcher recently brought in LED light equipment, which would mimic sunlight for his space-grown plants, Silva took one look at it and said, “it will break. You must replace this component with another.”

The institute helped assemble the network’s newest suborbital experiment, scheduled to blast off from one of Brazil’s launchpads in September. A small craft will carry microbes that feed nitrogen to soybean plants, a biological process that on Earth has reduced the usage of chemical fertilizers, which contribute to greenhouse-gas emissions. Scientists will study how the tiny organisms fare in reduced gravity; any farmers using Mars's nitrogen-poor soil would surely want to bring them along.

Bridging the Gap Between Earth and the Cosmos

Brazil’s program is in its early days, but one member of the project, Serguei Balachov, a researcher at Centro de Tecnologia da Informação Renato Archer, shared a 1960s-era Soviet song that captures a vision for humankind’s space farming efforts. As is often the case with translations, sounds lovelier in the original Russian, but it goes like this: "To live and to believe is wonderful / In front of you are paths unheard of / Cosmonauts and dreamers insist / That apple trees will bloom on Mars.”

Martian apples—or the potatoes grown by fictional botanist Mark Watney in The Martian—are still the stuff of dreams. But one immediate outcome of Brazil’s program is that it has brought together an eclectic mix of aerospace engineers and plant scientists, and like Fávero, some of the agricultural experts have suddenly become enthusiastic space fans. Paulo Hercílio Viegas Rodrigues, of the Luiz de Queiroz College of Agriculture, has perhaps the best conversion story: Rodrigues once spent just over a year in Florida on sabbatical, during which he visited Disney World 52 times, never thinking to check out the nearby Kennedy Space Center. “I’m a professor of flowers,” he says in his office in Piracicaba, which is now covered in space memorabilia. The decor includes a once-forgotten letter from NASA, commemorating the fifth anniversary of the Apollo 11 landing, which he received as a child in 1974, after his mother had written the agency. More plant scientists may need to dabble in rocket science in order to make farming on the red planet a reality.

Back in Campinas, Purquerio and Kainan take me on a drive around the grounds, where dainty white blossoms adorn the branches of the coffee trees, and bulbous pink flowers dangle from the vines of cannonball trees. The thought of space travel feels so far away here, in a rolling, viridescent realm of fauna, hoisted from the soil by hundreds of millions of years of evolutionary memory of one particular planet, holding the story of Earth in roots, stems, and leaves.

Future space missions, packed with seeds and sprouts meant for a cosmic harvest and a good meal, can shorten that distance. As humans embark on grander, more perilous journeys, they’ll bring pieces of this planet with them to nourish bodies and minds that didn’t evolve to function anywhere else—because, cosmically speaking, there’s no place like home.