NASA has led the charge in space exploration for more than six decades, and through the new Artemis program, they will build on their work in low-Earth orbit.
NASA’s Artemis lunar exploration program includes sending a suite of new science instruments and technology demonstrations to study the Moon, landing the first woman and next man on the lunar surface by 2024, and establishing a sustained presence by 2028. The agency will leverage its Artemis experience and technologies to prepare for the next giant leap – sending astronauts to Mars.
NASA and its international and commercial partners have demonstrated skill in solving the challenge of feeding crews in low-Earth orbit. Astronauts have lived and worked continuously in space for more than 20 years (Nov 2 2000) , eating mostly packaged foods along with some fresh foods delivered on regular resupply missions.
In preparation for Artemis missions to the Moon and beyond, researchers are developing ways to sustain explorers for missions to destinations beyond low-Earth orbit including Mars, missions that may last for months or even years and have limited opportunities for resupply missions.
Scientists are new using LED lighting technology to supply the plants with vital nutrition, this includes both manual and automated growth environments. Even though growing plants in space is still hard, these experiments show that it is possible to grow edible essential plants under controlled conditions.
Astronaut Serena Auñón-Chancellor harvests red Russian kale and dragoon lettuce from Veggie on Nov. 28, 2018, just in time for Thanksgiving. The crew got to enjoy a mid-afternoon snack with balsamic vinegar, and Auñón-Chancellor reported the lettuce was "delicious!"
Plants in Space
Plants will be useful and attractive as humans explore space. Our pioneering astronauts have shown us that fresh flowers and gardens on the International Space Station (ISS) create a wonderful ambiance and allow us to take a piece of Earth with us to reduce homesickness.
They’re helpful for our psychological well-being on Earth as well as in space, and long-term missions will require them to keep astronauts healthy.
Back in the days of ocean travel vitamin C deficiency regularly caused sailors' scurvy and other health issues. Astronauts in deep space will need more than multivitamins to battle malnutrition. Fresh vegetables will be needed for both the mental and physical success of our explorers.
Currently, resupply missions supply astronauts with a choice of freeze-dried and packed meals. However, prepackaged vitamins degrade over time, and months or years without resupply will pose a significant health risk to the astronauts.
NASA is looking into ways to provide astronauts with nutrition that is long-lasting and easily absorbed - these include freshly grown fruits and vegetables in a contained environment without sunlight or gravity. Such conditions pose unique challenges to the success of life. To tackle the problem, NASA and partners have begun experiments that carefully measure the conditions required to consistently grow fresh plants.
NASA astronaut Peggy Whitson is seen during harvesting and
cleaning of VEG-03 in the space station’s Node 2. VEG-03 used
the Veggie plant growth facility to cultivate a type of cabbage to
be harvested in orbit, with samples returned to Earth for testing.
The Vegetable Production System
The Vegetable Production System, known as Veggie, is a space garden residing on the International Space Station (ISS).
Veggie helps NASA investigate plant development in microgravity while feeding astronauts fresh food and improving their well-being. The veggie garden accommodates six plants and is the size of a carry-on.
Each plant grows in a clay-based "pillow" with nutrients. The pillows balance water, nutrients, and air around the roots. Because space fluids produce bubbles, the roots would drown or be consumed by air.
Without gravity, plants utilize light to orient and guide growth. A bank of LEDs (Light Emitting Diode) above the plants generates a plant-friendly spectrum. The Veggie chamber glows magenta pink because plants reflect green light and utilize red and blue wavelengths.
The management of light in the enclosure is crucial to success. NASA scientists will test the best combinations of light wavelengths, duration, and intensity for effective plant growth in space.
Veggie has grown three lettuces, Chinese cabbage, mizuna mustard, red Russian kale, and zinnia flowers. Recently, astronaut Scott Kelly captured a zinnia flower floating in the cupola against the backdrop of Earth.
The astronauts ate some plants and sent the rest to Earth for analysis. The crew has enjoyed safe, tasty food without infection. Kennedy Space Center wants to grow more tomatoes and peppers while berries, beans, and other antioxidant-rich foods could protect astronauts from space radiation.
NASA astronaut and Expedition 65 Flight Engineer Mark Vande Hei prepares for the routine debris removal procedure for chile peppers growing in the Advanced Plant Habitat as part of the Plant Habit-04 experiment being conducted aboard the International Space Station. The chile pepper seeds started growing on July 12, 2021, and represent one of the longest and most challenging plant experiments attempted aboard the orbiting laboratory. They will be harvested twice, once in late October and again in late November. Astronauts will sanitize the peppers, eat part of their harvest, and return the rest to Earth for analysis. What we learn will inform future crop growth and food supplementation activities for deep space exploration.
Advanced Plant Habitat
Veggie and the Advanced Plant Habitat (APH) are station growth chambers for plant research. LED lights and a porous clay substrate with controlled-release fertilizer supply water, nutrients, and oxygen to plant roots control the nutrition and position of the vegetables.
Unlike Veggie, APH is contained and automated with cameras and more than 180 sensors in constant interactive touch with a staff at Kennedy Space Center, so it doesn't need much daily care from the crew.
Water recovery, distribution, atmosphere, moisture, and temperature are all automated. It includes more LED lights than Veggie, including red, green, blue, white, far red, and infrared for nighttime imaging. The LED light technology is critical to successful growth.
The crew takes plant samples, freezes or chemically repairs them, and sends them back to Earth to study how space influenced their growth and development.
Arabidopsis thaliana and dwarf wheat were used for APH's first space station test in Spring 2018. The space station's time-lapse video became viral globally.
The first APH project, the Arabidopsis Gravitational Response Omics (Arabidopsis-GRO) consortium, is led by Dr. Norman Lewis. He and his coworkers study plant gene, protein, and metabolite variations in space.
They want to know how microgravity affects plant lignin. Plant ligins work like human bones. They provide plants with structure and gravity resistance. Humans lose bone and muscle in space due to fewer physical demands. But how will Lignins survive?
Lewis and his team also want to know if genetically altered plants with less lignin can survive and function in space. This may improve human nutrient uptake and composting of space-grown plants. Lewis and his team believe this fundamental science data will guide deep space exploration and colonization.
Lewis knows space science has advanced and that the possibilities ahead were once fiction!
Seen in the image above is Biological Research In Canisters (BRIC) hardware being used in 2017 as part of a previous experiment, BRIC-22, on the International Space Station. Similar hardware will be used for the BRIC-24 experiment, slated to arrive at the orbiting laboratory on SpaceX's 22nd cargo resupply mission.
Biological Research in Canisters
The Biological Research in Canisters (BRIC) laboratory studies how space affects yeast and bacteria in petri dishes. The latest iteration, BRIC-LED, includes light-emitting diodes (LEDs) to help plants, mosses, algae, and cyanobacteria create food.
What differentiates this hardware from the previous BRIC-PDFU series is the customizable discrete lighting that illuminates the individual 60 mm petri dishes. Four different wavelengths of LED’s are available for each petri dish (blue, red, far-red and white) and are configured as specified by the investigator.
Temperature will be controlled to ± 3°C of the surrounding air temperature, with no more than a 1.5°C differential between canisters, using forced air cooling. Additionally, the BRIC-LED will provide temperature and LED status, canister pressure and accelerometer data to scientists.
Dr. Simon Gilroy of the University of Wisconsin-Madison studies Arabidopsis gene expression in space. “There are literally thousands of experiments done on Earth [on Arabidopsis],” Gilroy explains. “Cold shock. Touched them. Not watered them. Too much water. Shouted at them,” he says with a chuckle. “Those databases are all available to us. So we look and see if there are any patterns anyone has found and what on the ground mimics what happens in space.”
Changes in gravity-related genes are expected. Gilroy has noticed two immune system tendencies in plants.
Oxidation appears to stress plants. Cellular chemistry produces a reactive oxygen-based molecule. Uncontrolled "reactive oxygen species" can damage mitochondria or DNA repair machinery. Healthy plant cells can handle it but in space, plants produce more.
Other immune system genes turn on and off in space. Scientists think this may reduce the plant's infection resistance.
Veggie's zinnias were overwatered and lacked airflow and some plants died from fungus. However, astronaut Scott Kelly tenderly removed the fungus, revived the plants, and made them flower. Space may have weakened the zinnia, but research is ongoing.
Scientists hope to use BRIC-LED gene expression studies to fool Veggie plants into believing they're threatened instead of purposely making them sick. They monitor plant protein sensors that constantly search for microorganisms.
Flagella, which helps bacteria swim, shares 22 amino acids called "flag-22." Plant defense mechanisms activate when flag-22 is detected. Scientists can spray harmless flag-22 solutions on plants and the plant thinks it is being attacked.
After 10 days, scientists dripped flag-22 on small plants in the BRIC-LED experiment. After an hour, scientists apply a chemical fixative to stop all biological activity. The plants are deep-frozen after this fixative preserves their responsive condition. The plants are returned to Earth, crushed up for RNA extraction, and studied for alterations to the original DNA.
To Infinity and Beyond!
This research will help NASA grow plants in space for long-term missions, including the upcoming Artemis mission. The use of LED lights are critical for the success of the experiment and for our species' ability to achieve long term space travel. While the research is just beginning, it has shown promising results, potentially allowing us to travel further from home than ever before!
