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Veronica Ann Zabala-Aliberto is involved in a closed-system farming experiment on Earth, which could be valuable for future space exploration and colonization. This experiment takes place at the Mars Desert Research Station in Utah. View more astronaut photos.
George Frey/Getty ImagesImportant Insights
- Space farming examines how plants grow in microgravity, focusing on how roots and stems align under reduced gravity, a key factor for farming on the Moon or Mars.
- In space, managing energy efficiently is essential, which is why scientists use light-emitting diodes (LEDs) to replicate natural sunlight for plants, taking into account energy use, heat production, and longevity.
- Experiments with various rooting materials help optimize water and air flow in low gravity. Space farming equipment must be compact and integrated with life support systems to regulate carbon dioxide and oxygen exchange effectively.
Have you ever thought about where we'll build homes and expand communities as Earth's habitable land becomes more limited? Maybe space could become the next suburban area. But before we begin sending children on intergalactic school buses, we first need to find new methods for accomplishing everyday tasks in space, like growing food. Global organizations are dedicating resources to developing ways to sustain human life beyond Earth. Some of the objectives of space programs include returning to and eventually settling on the Moon, along with upcoming manned missions to Mars.
The International Space Station (ISS) serves as a collaborative platform to address the vital challenges of sending humans into space for extended periods. Overcoming these challenges is essential before embarking on long-duration flights or establishing permanent habitats in space.
Astronaut Photography Collection
Space farming requires a deeper understanding if humans are to thrive in space without constant reliance on Earth. Space farming involves cultivating plants in outer space. While this may seem simple at first, the unique characteristics of space and our ability to survive and travel in this environment add significant complexity to the task.
Fortunately, the ISS is home to a team of astronauts (no gardening experience needed) from all corners of the globe, each specializing in various scientific and engineering disciplines. These astronauts conduct experiments to expand our knowledge of growing plants in space and contribute to many other fields of science. Back on Earth, researchers and scientists analyze the results, devise new theories, and develop possible solutions for further testing.
Before diving into the advancements made by experts in space farming, let's take a moment to explore the challenges they face.
The idea of a space station had been floating around since the Reagan era. In 1993, the U.S. and Russia agreed to merge their respective space station plans and invited other nations to join the project. The first components of the ISS were assembled in orbit in 1998, and the station has steadily expanded ever since. Astronauts took up residence in 2000, and two years later, they installed Lada, a greenhouse mounted on the station's wall, used for experiments and providing fresh produce. The European Modular Cultivation System, a second research facility aboard the ISS, is dedicated to plant studies and various experiments.
The Obstacles of Space Farming
Plants aboard the ISS are cultivated in specialized growth chambers. Astronauts conduct experiments on both the plants and these chambers, working to improve the techniques and processes of space farming.
Photo credit: NASATo grasp the challenges of space farming, let's explore some of the key factors influencing plant growth in outer space.
Reduced Gravity
Current space farming studies focus on various aspects of farming in microgravity (an environment with minimal or no gravity). These experiments could have relevance for farming on the moon or Mars, which have much lower gravity than Earth. Plants rely on gravity to guide their growth, particularly in terms of root and stem orientation. Scientists are studying whether plants can grow properly with reduced gravity, and determining what specific gravity levels are necessary for growth.
Artificial Illumination
On Earth, plants naturally grow towards abundant sunlight, but in space, researchers need to trick plants into following this instinct. The choice of lighting in the growth chambers is crucial for several reasons. Space resources are limited, so energy efficiency is vital. It's essential to avoid wasting energy on bulbs that don't optimize their output. Different light sources also generate different amounts of heat, and spacecraft must minimize extra heat. For this reason, light-emitting diodes (LEDs) are favored due to their energy efficiency and low heat emission. Additionally, astronauts don't have space for spare light bulbs, so durable lighting sources are a must.
Different Rooting Substrates
The absence of gravity can impact the effectiveness of rooting materials. Some soils and materials are better than others at distributing water and air, which are both essential for plant health. In space, coarse soils may cause water to disperse unpredictably, while fine soils may hinder airflow [source: Franzen]. Researchers are testing a range of materials, including clay particles, hydroponics, and peat moss, to find the best solution for space farming.
Contaminants
Plants rely on the spacecraft's air, humidity, and microgravity—conditions unlike those on Earth. Researchers are investigating whether contaminants or harmful organisms from space could affect these plants, making them unsafe for human consumption. Changes to their genetic makeup could cause additional concerns. There's also the risk that if astronauts bring these space-grown plants back to Earth and mix them with Earth-grown crops, we might inadvertently create a space-borne version of kudzu. Kudzu (Pueraria montana) is an invasive plant species introduced to the U.S. from Japan in the late 1800s.
Limited Space for Growth
The cramped interiors of spacecraft contrast sharply with the vast, open farmlands on Earth. Researchers must create a highly efficient, compact system to grow crops in such confined spaces. These growing systems must be automated (or at least capable of automation) and regulate factors like watering, humidity, lighting, air flow, and nutrient delivery. Additionally, these systems need to integrate with the life support system to ensure proper exchange of carbon dioxide and oxygen.
So when will astronauts have access to space's first salad bar? It could take some time, as researchers continue to study and overcome the challenges of space farming. Continue to the next page to explore their research and discover why insects may become the space food of the future.
Space Farming Research
The International Space Station floating above Miami.
StockTrek/Digital Vision/Getty ImagesResearch in space farming generally targets plants that produce abundant edible parts and can thrive in confined spaces. Scientists have started growing various plants in space, including thale cress, lentils, wheat, salad greens, field mustard, and soybeans.
Through these plants, researchers are figuring out how future space farming operations will work. Like on Earth, plants require essentials such as water, carbon dioxide, and nutrients. Although plants can survive with little gravity, having some gravity is optimal to avoid growth issues. To address this, artificial gravity created by a mechanical centrifuge is being tested. Experiments control the intensity and duration of artificial gravity to understand its influence on root growth direction. Fortunately, both the moon and Mars have some gravitational pull, which will assist in supporting plant life on these planets.
So far, the results of space farming research have been varied. In some experiments, plants and seeds returned from the ISS showed similar characteristics to the control group grown on Earth. In other cases, the plants were somewhat larger or taller. In several instances, researchers noted considerable differences between plants grown in microgravity and those grown under Earth's gravity.
For example, research on NASA's Biomass Production System (BPS) revealed that while the two sets of plants grew similarly, the immature seeds grown aboard the ISS developed at different rates compared to the control group. The seeds grown on Earth had uniform development rates, while the space-grown seedlings showed varying levels of protein and soluble carbohydrates. This might alter the flavor of food grown in space, according to researchers.
However, it’s essential to consider that these varied results might stem from differences in control factors such as temperature, light, and humidity across experiments, the diversity of growth equipment, and the inherent challenge of cultivating plants in space.
Having explored the challenges of space farming, let’s now examine why this research is pivotal to the future of space exploration.
Whether or not they possess wings, certain insects could become part of space farming experiments, possibly even flying to space. While many plant parts are unsuitable for human consumption, they can serve as food for insects. These insects are capable of converting inedible plant material into valuable resources, such as fertilizer.
Insects also offer a reliable source of nutrition for humans or animals in space. A grasshopper, although perhaps a bit crunchy, could provide astronauts a welcome alternative to dehydrated meals. Moreover, some insects could play additional roles for long-term space missions. For instance, silkworms can produce silk that can be woven into ropes and clothing.
The Impact of Space Farming
Astronauts C. Michael Foale (left) and Alexander Kaleri, part of the Expedition 8 crew aboard the ISS, stand alongside the Lada greenhouse.
Photo courtesy NASAWhile much of the research carried out by NASA and other space agencies plays a crucial role in advancing space programs, the potential benefits of space farming extend to many practical applications on Earth.
The primary goal of space farming research is to support long-term space exploration by providing astronauts with a sustainable food source. Picture going on a year-long trip and needing to bring every meal with you -- your car would be overflowing with groceries.
In addition to feeding astronauts, plants can assist the life support systems by purifying water and converting carbon dioxide into oxygen. If scaled up, plant-based systems could drastically influence the design of spacecraft and future space colonies.
On Earth, the advancements in space farming will deepen our understanding of agriculture. Scientists are eager to apply lessons from growing food in the harsh environment of space to solve similar challenges here. Their goal is to enhance food production in areas with limited arable land, improve crop quality and yield, and develop more efficient agricultural systems and greenhouses.
Space farming has resulted in a range of surprising and beneficial innovations here on Earth. One such innovation is the Bio-KES device, which uses ultraviolet light to convert ethylene into carbon dioxide and water. Ethylene is a gas that triggers the ripening and eventual spoiling of plants. Devices like Bio-KES, which are employed in food storage and display units, could extend the shelf life of fruits, vegetables, flowers, and other perishables. Ultraviolet light's applications go beyond food preservation; it can also eradicate harmful pathogens like anthrax, accelerate wound healing, and enhance certain cancer treatments.
Another potential breakthrough emerging from space farming involves the study of plant cell walls. Scientists are working to understand how to control and regulate the sturdiness of a plant's structure. This could lead to improvements in plants' ability to withstand harsh weather. Moreover, trees with less rigid cell walls could grow more rapidly and be processed more easily and affordably into paper. Genetically modified trees like these could play a significant role in combating deforestation by providing a fast-growing, sustainable resource for paper production.
Finally, plants appear to have a positive impact on mental well-being. Just as gardening or a stroll through the park can uplift spirits here on Earth, the same effect is observed for astronauts aboard the ISS. Plants and a thriving environment offer sensory stimulation and promote relaxation. After the Columbia disaster, astronauts turned to plants as a form of therapy to help cope with the loss of their colleagues [source: Quinn]. Researchers are now studying the psychological effects of plants by observing the amount of time astronauts spend cultivating plant life and engaging in gardening activities.
