January 27, 2022

This is How NASA Manages to Develop Chile Peppers in Area


A number of weeks in the past, astronauts on the Worldwide Area Station (ISS) loved a really particular feast of tacos, together with recent Hatch peppers grown in orbit. Greater than only a little bit of enjoyable for the crew, these have been the primary flowering crops grown, harvested, and consumed in area, and so they symbolize a leap ahead within the complexity of crops grown in microgravity.

To study the way you develop tasty, recent greens in area we spoke to LaShelle Spencer, the challenge science crew lead for the chile pepper experiment, who oversaw the challenge from deciding on and making ready the seeds to packing them up for launch to remotely monitoring the crops as they grew within the ISS and overseeing the primary harvest.

A comfy plant setting in area

The intention of the challenge was easy: To show it’s attainable to develop a posh flowering crop like chile peppers in area. Whereas it’s comparatively straightforward to develop leafy greens like kale on the ISS, and up to date initiatives have succeeded in rising greens like radishes as well as wheat, growing chiles is more complex than these previous projects — both because the plants require careful pollination and because it takes so much longer for them to grow (around four months) compared to quicker crops like lettuce and radishes.

The crops were grown in a special container on the ISS called the Advanced Planet Habitat, a fully-automated system that researchers on the ground can control remotely. Photos are taken of the plants within the habitat each day, and researchers can control many aspects of the environment like adjusting the red, green, and blue LED lights or the temperature inside the grow tank.

Expedition 66 astronauts sample chile peppers grown on the International Space Station.
NASA

The APH is a closed environment. Compared to when you grow in a window box, Spencer said, “You have mother nature. You have sun and the full spectrum [of light].” In APH, there’s only a limited spectrum of light available and the plants miss out on ultraviolet light — which causes peppers to grow tiny tumors on the underside of their leaves. This isn’t a problem for the type of Hatch pepper plant chosen, but it can be a problem for other varieties.

Another issue is fertilization. “We use time-release fertilizers,” Spencer explained. “We had to make sure we had the right mix of nutrients to carry us through a 120-day experiment. It’s a mix of calcium, magnesium nitrate, things like that. And when they’re gone, they’re gone. There’s no way to add any more nutrients to the system.”

Adjusting conditions on the fly

While Spencer’s team had a similar device to the APH in their lab for testing, and they used it to simulate what conditions the plants required, it was still challenging to predict exactly what conditions the chiles would need to grow in space. “We had to adjust on the fly,” she said, which they could do from the ground by tweaking factors like light levels in the habitat or the scrubbing levels of certain chemicals from the environment.

“In microgravity, the plants had a bushier morphology. The flowers opened straight up, and some of the fruits opened straight up as well.”

For example, the water requirements of the plants were different on Earth than they were on the space station, which they spotted by looking at photographs of the plants as they grew. “The water requirement is probably 10-15% higher than what we were doing on the ground,” Spencer explained, which was due to the way water rested and moved around the APH in microgravity.

Gravity-less plants grow strangely

Expedition 66 astronauts sample chile peppers grown on the International Space Station.
NASA

Even with all this tweaking, there were still differences in the way the plants grew in microgravity. In Earth’s gravity conditions, the type of chile used grows straight upward, with the flowers and fruit hanging down. “In microgravity, the plants had a bushier morphology and grew parallel to the science carrier [the tray in which the seeds are planted]. The flowers opened straight up, and some of the fruits opened straight up as well,” Spencer explained.

This difference in the shape of the plant isn’t just a curiosity either, as it may have affected how the plants are pollinated. Spencer’s team found that their chile crop was slower to pollinate in orbit than on the ground, and she thinks this might be because, when the flowers point upward, the air gusts that they use for pollination could have blown the pollen away from the flower, as opposed to shaking a downward-facing flower and letting the pollen mix within the flower.

“Because the microgravity environment affects [the crew’s] taste buds, they’ve always expressed a desire for spicier foods.”

“Microgravity definitely had a huge effect on plant morphology,” she said, but microgravity doesn’t affect all plants in the same way. “We’ve been growing leafy greens in VEGGIE for a while, and when we get the water right, they do very well. There’s nothing to say they’re any different than what we grow on the ground. Now that we’ve moved onto fruiting crops, there’s definitely a difference.”

One of the biggest differences was that the plants in space came out around 50% smaller than those on the ground. But the chiles they produced were still sizable, reaching up to around four or five inches in length.

Tasty space tacos

So why grow chiles? Well for starters, they’re high in vitamin C, and the plants are rugged enough to grow well even in difficult conditions. In addition to the nutritional aspect, the signature spiciness of the chiles is highly desirable among the astronauts, Spencer said: “The crew, because the microgravity environment affects their taste buds, they’ve always expressed a desire for spicier foods. They like hot sauce!”

For all the complexity in growing peppers, the first harvest was a great success. “It was awesome!” Spencer said. She and her team looked at photos of the pepper crop and sent instructions to astronaut Mark Vande Hei to pick seven of them for harvesting. They were mostly green, with one red pepper. Having carefully picked the peppers, the astronauts then diced them up and enjoyed them in tacos, which astronaut Megan McArther described as “Friday Feasting!”

Friday Feasting! After the harvest, we bought to style pink and inexperienced chile. Then we crammed out surveys (bought to have the information! 😁). Lastly, I made my greatest area tacos but: fajita beef, rehydrated tomatoes & artichokes, and HATCH CHILE! https://t.co/pzvS5A6z5u pic.twitter.com/fJ8yLZuhZS

— Megan McArthur (@Astro_Megan) October 29, 2021

A psychological increase

This factors to one of many large benefits of rising recent meals in area: Not solely is it good for astronauts’ bodily well being to eat recent veggies, but it surely’s additionally nice for his or her psychological wellbeing. Psychology experiments on the bottom have proven that nurturing crops may give emotions of satisfaction and satisfaction and will help enhance temper and cut back stress. It’s possible that the identical is true of astronauts, particularly contemplating they’re in an enclosed setting with little entry to nature.

Whereas Spencer’s crew continues to be ready for information about how the astronauts felt about taking care of the chiles (they fill out a questionnaire about their experiences as a part of the experiment), she did say that she thought the astronauts have been having a constructive expertise when she noticed them interacting with the crops. “I see pleasure on their faces once I watch them on the cameras,” she mentioned. “I can inform that they love the way in which they scent.”

The astronauts also can spend time with the crops in between the instances after they have been performing operations like harvesting. “They have been in a position to take the duvet off and look by the window on their off time,” Spencer mentioned. And that turned out to be helpful for the experiment as properly, as one of many crew members noticed a plant that was creating a typical subject referred to as blossom finish rot throughout their off time, which was then faraway from the crop.

What’s subsequent for crops in area?

With the primary harvest full, the experiment isn’t performed but. Extra of the chiles will proceed rising, and the following harvest is tentatively scheduled for November 26. Finally, some chiles might be introduced again to Earth, the place their genetic make-up might be in comparison with comparable chiles grown on Earth, and Spencer and her crew will carry out a dietary evaluation.

Spencer additionally says there are lots of extra questions she desires to research about how microgravity impacts pollination and fruiting, as we’re removed from having a whole understanding of how an absence of gravity impacts these advanced crops. For now, although, we’re one step nearer to offering astronauts with scrumptious, wholesome meals, and studying lots about crops within the course of.

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