Astronauts are growing chile peppers in space in spicy first

A batch of chile peppers seeds has been planted on the International Space Station as part of a new experiment that aims to expand the range of space-grown foods ahead of a possible future mission to Mars.

The 48 Hatch chile pepper seeds arrived at the orbital outpost  June 5 with  the SpaceX Dragon CRS-22 commercial resupply mission. Now, the red and green chile peppers are starting to grow as part of NASA's Plant Habitat-04 experiment, the agency said in a Tuesday (July 13) statement.

Astronauts get most of their fresh food supplies from cargo ships, but earlier versions of the Habitat experiment already produced some tasty treats. During the previous three harvests, crews have enjoyed space-grown red lettuce, Mizuna mustard and two other lettuce types, and radishes. Astronauts have also grown flowering plants, such as zinnias, to spruce up their living quarters.

Current Expedition 65 astronaut Shane Kimbrough, who got to sample space-grown outredgeous red romaine lettuce during his 2016 mission, himself initiated this version of the Habitat experiment. Unfortunately, Kimbrough will likely be back on Earth by the time the chile peppers are ready in four months, as he and other SpaceX Crew-2 astronauts are expected to splash down in October.

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NASA astronaut Shane Kimbrough inserts a device called a science carrier into the Advanced Plant Habitat (APH), which contains 48 Hatch chile pepper seeds NASA started growing on July 12, 2021 as part of the Plant Habitat-04 experiment. (Image credit: NASA)

Nevertheless, the experiment team with NASA Kennedy Space Center's exploration research and technology program paid tribute to the crew's efforts to continue developing space food as part of a larger research effort to feed astronauts on deep space missions. Once on the moon or Mars, astronauts will not be able to rely on supplies from Earth and will have to grow more food locally. That's where the Habitat research will fit in, its team stated.

"It is one of the most complex plant experiments on the station to date because of the long germination and growing times," Matt Romeyn, principal investigator for Plant Habitat-04, said in the NASA statement. "We have previously tested flowering to increase the chance for a successful harvest because astronauts will have to pollinate the peppers to grow fruit."

The experiment is hosted in the Advanced Plant Habitat, one of three plant chambers in which astronauts can grow and harvest food, flowers and other crops. Much of the maintenance work can be performed remotely by teams on the ground at Kennedy, reducing the hands-on time by busy astronauts in orbit.

Astronauts are known to get stuffy heads in microgravity, so spicy foods are often on the menu anyway to help encourage them to eat. This pepper variety, called the NuMex 'Española Improved' pepper (a hybrid Hatch pepper) naturally grows in zones such as New Mexico, NASA said. Researchers spent two years deciding among two dozen varieties before picking this one for a space ride, due to its potential for feeding astronauts on missions further away from Earth.

"We are limited to crops that don't need storage, or extensive processing," Romeyn said. All peppers also have the advantage of being dense in Vitamin C and other nutrients, providing good nutrition along with taste. Additionally, the colorful red – which will pop up late in the growing cycle – may benefit the astronauts' mental health, based on past studies suggesting bright vegetables are a boon, Romeyn added.

The crew will sample some of the 48 peppers (that number assumes all the seeds planted make it to maturity), and send the rest back to Earth for further analysis. The science team will evaluate the flavor and texture of the peppers from crew feedback, along with Scoville measurements, which evaluates the plants' "heat" or spiciness. That, the researchers said, can depend in part on the environment in which it was grown, so changing how much water, light and heat the plants get might actually affect how hot they will be.

"The combination of microgravity, light quality, temperature, and rootzone moisture will all affect flavor, so it will be interesting to find out how the fruit will grow, ripen, and taste," LaShelle Spencer, Plant Habitat-04's project science team lead, said in the same NASA statement. 

"The food astronauts eat needs to be as good as the rest of their equipment," Spencer added. "To successfully send people to Mars and bring them back to Earth, we will not only require the most nutritious foods, but the best-tasting ones as well."

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: