Figuring out how to feed astronauts during long missions to the Moon and Mars has proved to be a key challenge for NASA and other space entities. The current solution – prepackaged, preserved food – requires regular deliveries from a cargo spacecraft and "degrades in quality and nutrition," as NASA puts it. This can prove to be both expensive and complex.
In an attempt to find a better solution, researchers have begun testing space agriculture, or the idea of growing plants in space. This is not only for the purpose of feeding astronauts, but also for supporting their psychological well-being and boosting morale on long, isolated missions.
Challenges of Growing Plants in Space
Although there are obvious challenges to growing plants in space, such as limited availability of water, habitat for growth, and nutrients, there are some more hidden obstacles, too.
Lost without Gravity
Growing plants in space involves a unique environment with unique challenges, primarily due to the effects of microgravity. In a zero-gravity environment, plants struggle to orient themselves properly, as their natural response to gravity doesn't function the same way. Essentially, the plant doesn't have the same instinct for the roots to grow downwards and the stems to grow upwards, which can affect development and nutrient absorption.
However, many plants are able to adapt and use other biological cues, like light, to orient their growth. NASA actually found that "microgravity alters leaf development, plant cells, and the chloroplasts used in photosynthesis, but did not harm the plants overall. In fact, wheat plants grew 10% taller compared to those on Earth. "
Radiation & Rogue Genes
Another factor that presents itself in space is epigenetic change and radiation. NASA found that plants exposed to spaceflight undergo changes in their DNA, which affects how the genes turn on and off. They are now researching to see if these changes can be transferred or passed on to the next generation.
This kind of research is important for us Earthlings as well, because it could help "support the development of strategies for adapting crops and other economically important plants for growth in marginal and reclaimed habitats on Earth." If new innovations are used for farming in space, these systems could be brought back to Earth to help us farm more efficiently, potentially using less water, land, and resources. It could also make farming more viable in harsh climates, helping with food security as the climate shifts.
Farming without Soil or Sun
NASA has designed several strategies for supporting plant growth in space. The two main issues are limited resources like water and space and lack of sunlight, all of which are essential for plant growth. In response to this, creative solutions to farm without soil or sunlight have been developed.
Hydroponics & Aeroponics
Hydroponics and aeroponics are two soil-free farming methods that have potential to be implemented in space. Hydroponics involves growing plants in nutrient-rich water instead of soil, allowing roots to absorb minerals this way. Aeroponics is similar, but instead of water, plants are grown in a mist of nutrients, allowing the roots to be exposed to open air. Both methods are water-efficient and require less space, which is important in outer space.
LED Lighting
Plants grown on a spaceship need some sort of replacement for the sun, which can be replicated using LED lights. LEDs are unique because they can be customized to emit specific wavelengths of light depending on the plant and conditions. In this way, the LEDs can exactly replicate the effects of the sun, while also being extremely energy efficient.
NASA's Veggie
In 2014, NASA developed a Vegetable Production System, named Veggie, aboard the International Space Station. This plant growth unit is specially designed to cultivate fresh produce in microgravity with the goal of studying plant growth in space environments and providing astronauts with a nutritious food source.
NASA explains that "seeds are grown in small fabric 'pillows' that crew members look after and water by hand, much like caring for a window garden on Earth." Since the beginning of the trials, Veggie has successfully cultivated an array of different plants, including many vegetables like red romaine lettuce, zinnia flowers, and Chinese cabbage.
Beyond nutritional benefit, growing vegetables also contributes to important systems such as oxygen purification, carbon-dioxide removal, and water purification. The presence of plants has also been shown to improve the emotional well-being of astronauts and to offer psychological comfort.
Continuing the Conversation
Interested in hearing more about space? This year at VivaTech, we'll be hearing from speakers like Vanessa Wyche, Acting Administrator of NASA, and other experts on space. Get your pass today and don't miss it!
