As humanity looks towards space exploration and colonization, there are many challenges that must be overcome. One of the most important of these challenges is providing a sustainable source of healthy nutrition for the people who will be living and working in space for extended periods of time. Fortunately, scientists and researchers are already at work developing new technologies and techniques to make this a reality.
The Evolution of Space Nutrition
The main goal of space nutrition is to provide reasonable support for optimal physiological and psychological well-being in space while accommodating diverse tastes, variety, and acceptability. Space nutrition must meet daily human needs for essential nutrients such as protein, fat, sugar, inorganic elements, trace elements, fat-soluble vitamins, and various water-soluble vitamins.
The evolution of space nutrition started from an initial focus on calorie-dense, nutritious, and palatable food without provisions for specific food storage on the spacecraft for short-duration missions. What followed was a shift towards packaged foods such as cans, food bars, and retort pouches as missions became longer from the mid-1960s to the early 1970s. The development of food refrigeration and heating equipment on manned spacecraft facilitated the adoption of thermal stabilization bags, canned fruit, irradiated meat, and freeze-dried food in subsequent stages of space flight. Currently, astronauts aboard the ISS are able to eat fresh vegetables, fruits, and heated soup for most meals.
The most common space food categories, include canned food, dehydrated food, medium moisture food, natural food, refrigerated food, fresh food, irradiated food, and functional food. Despite its short shelf life, fresh food has been and will still be necessary for improving space food acceptability. The ISS provides astronauts with fresh food, mainly fruits and vegetables for direct consumption or vegetable salads. However, the following limitations call for more innovation in space nutrition: the dominance of processed over fresh food, no quality advantage for resource-intensive refrigerated and frozen food, limited transportation and storage space, long-term space nutrition requirements for food storage and cooking methods, and diet menu fatigue.
Overall, the development of sustainable food production systems that provide fresh, nutrient-rich food with distinctive, original flavors is crucial to increasing astronaut appetite and improving their physical and psychological well-being during long-term space missions.
The Challenges of Long-term Space Nutrition
The field of long-term space nutrition is a critical area of research for the future of manned space missions, particularly those involving extended stays in outer space.
The adoption of specific dietary measure can contribute to prevent adverse environmental factors and nutritional deficiencies, selecting the right types of foods and supplements, and engaging in specific sustainable food production and eating practices. However, to support self-sufficiency during long-term space exploration, future space nutrition systems will need to be supported by fresh food production, nutrient recycling of food scraps, and the establishment of closed-loop biospheres or landscape-based space habitats able to support life in space in the long term.
Humans have been involved in manned spaceflight for the past five decades. Recently, the International Space Station (ISS) has become the primary destination for short-term missions. However, major space agencies are planning for a long-term human presence in space, including missions to the Moon and Mars. Extensive research is being carried out by various researchers to support long-term human presence in space, including the Hawaii Space Exploration Analog and Simulation (HI-SEAS) III expedition, which involved an 8-month isolation mission to simulate conditions on Mars.
For short-duration missions, astronauts rely on nutritional supplies carried from Earth and sustained by specialized delivery missions. However, the techniques used for processing these food products limit their nutritional value and can lead to menu fatigue and consequent high risk of astronauts’ undernutrition. Processed space foods cannot provide the full range of diverse nutrients necessary to help astronauts effectively combat various physiological challenges associated with the extreme environment in space SUCH AS?. Therefore, fresh food materials are necessary to compensate for the deficiencies in the existing space nutrition system, which largely relies on processed food. In fact, the lack of fresh fruits and vegetables and fiber-rich meals has been associated with digestive problems even with the use of supplements to increase nutrient diversity.
Advanced lighting, irrigation, and greenhouse systems have been developed to optimize plant growth in outer space and make fresh space foods possible. Self-sufficient closed-loop ecosystems of resource production and regeneration will be necessary to provide renewable resources that minimize energy consumption and maximize the use of higher plants and other autotrophs for deep space exploration resupply programs. Moreover, the success of commercial space activities and space tourism depends on optimizing long-term space nutrition for the likely multi-cultural space tourists and inhabitants of the future.
The challenges of providing adequate nutrition for astronauts during long space flights are represented by the extreme conditions such as microgravity, radiation, confined space, motion sickness, and circadian rhythm changes. The lack of gravity and circadian rhythm are well-known and widely studied aspects of spaceflight, but there is a need for a more comprehensive nutritional study on other ancillary conditions, such as food taste alteration and the adaptations of human digestive, olfactory, and perception systems to long-term space habitation.
Astronauts need to consume more food to offset the decrease in their energy intake due to microgravity, small spaces, insufficient exercise, and shortened circadian rhythm changes. However, the poor palatability of processed and packaged space food causes the astronauts to eat less, leading to a negative energy balance that results in weight loss. Chronic energy deficiency can exacerbate some harmful physiological adaptations to the space environment, resulting in cardiovascular dysfunction, bone density, muscle mass and strength loss, impaired exercise ability, and immunodeficiency. These physiological changes may jeopardize the health and performance of the crew, as well as the overall success of the mission.
Microgravity can impact on human physiology by causing fluid redistribution, reduced plasma volume, rapid loss of muscle mass and strength, cardiovascular deconditioning, impaired aerobic exercise capacity, bone-loss, immune and metabolic alterations, as well as effects on the central nervous system. Long-term exposure to space radiation can cause harmful effects such as DNA damage and cell aging. Metabolic stress and associated oxidative stress and inflammation are also a concern, as they have been implicated in the process of muscle atrophy and bone loss.
Other challenges facing astronauts include changes in physical condition, such as an impaired convective heat transfer and evaporation process to cool down the body, low-grade pro-inflammatory responses to weightlessness, psychological stress-induced hyperthermia, and intestinal microecology disorder. Astronauts may also experience vision damage, fluid and electrolyte imbalance, and other adverse health effects.
To mitigate these challenges, functional foods rich in anthocyanin and omega-3 fatty acids have been used to slow down the damage caused by radiation. Nutrient-dense food can also help increase energy intake more efficiently through eating. Exercise is also important for reducing muscle and bone loss and cardiovascular cleansing, but it increases total energy expenditure, necessitating a greater energy intake to maintain energy balance. Finally, fresh, tasty food can stimulate the astronauts’ appetite and help them eat more.
Health Risks Related to Nutrition in Space
Improper nutrition can lead to a range of health risks, including deficiencies in protein, vitamins, minerals, and other essential nutrients. In addition, the space environment presents unique challenges for food production, storage, and consumption, making it difficult to provide astronauts with fresh, palatable, and nutrient-dense foods.
Research is undergoing to develop effective means of providing fresh, nutrient-dense foods in the space environment and to better understand the complex interactions between diet, microgravity, and other physiological factors.
One major concern is the impact of weightlessness on skeletal muscle function and structure, which can lead to muscle atrophy. Studies of astronauts on long flights lasting more than 100 days have shown that protein synthesis decreases, likely due to a lack of energy intake. Astronauts need to consume more protein than the average person to combat this issue. Branched chain amino acids can also be supplemented to help fight muscle atrophy.
Another concern is the impact of space radiation on human tissues, which can lead to cataracts, reduced immunity, and an increased risk of cancer and genetic damage. To combat these effects, astronauts can consume a diet rich in natural antioxidants such as procyanidins, omega-3 fatty acids, vitamin E, vitamin C, beta-carotene, selenium, and foods with antioxidant properties such as tomatoes, garlic, nuts, oats, blueberries, broccoli, salmon, and green tea. Certain foods like buckwheat, which contains high amounts of vitamin P and selenium, can also help enhance human body performance.
Nutrient loss during food processing and storage is another major concern. Storage temperature and time have a significant impact on the vitamin content of space food, and thermally stabilized foods undergo destructive heat treatment processes that result in nutrient loss and flavor deterioration. Certain vitamins, such as vitamin A, C, thiamine, and folate, are particularly prone to degradation during storage, and nutrient loss can lead to undernutrition during long-term missions. New processing techniques and storage conditions are needed to address this issue.
Proper food packaging is also crucial, as packaging materials such as aluminum foil and plastic can introduce toxic compounds into food over time. Plasticizers and bisphenols have been shown to migrate from plastic packaging into food, while aluminum foil can dissolve in acidic and alcoholic foods, causing heavy metal pollution. New packaging technologies such as modified air packaging, active packaging, intelligent packaging, and nanomaterials for packaging have been developed to extend the shelf life of packaged foods, but they have limitations and can only extend shelf life by a few days to a year.
Packaged food cannot meet the health needs of astronauts during long-term space missions due to the loss of nutrients during food processing, preparation, and storage, as well as the health risks associated with using packaging materials and food additives. At the same time, ready-to-eat space food cannot meet the astronauts’ psychological needs for a sense of familiarity from undertaking their normal eating habits and maintaining their food culture, and a sense of community from engaging in food production, preparation, and consumption as social activities.
Resupplies for long-term space mission are cost-prohibitive, and long-term space nutrition systems need to rely on self-sufficient bioregenerative systems to produce fresh foods. Incorporating nature-based environments within a landscape-scale space habitat will be a critical path to providing sufficient fresh food to space inhabitants as a form of complex medicine required for long-term psychophysiological wellbeing and countermeasures to the adverse living conditions in space.
Additionally, fresh food production helps astronauts maintain a sense of familiarity and community, which is crucial for psychological well-being. Fresh food production through the use of closed-loop systems remains necessary for providing a diverse range of nutrients while working within the limited payload threshold allowed by each space flight. There is an urgent need for sustainable production of fresh food with distinctive, original flavors to increase appetite. During long-term space missions, enabling a self-sufficient lifestyle through the use of a nature-based regenerative life support system will help astronauts better adapt to the adverse conditions of the space environment. A landscape-based approach to space habitat design helps engender a sense of place attachment from biophilia. Place attachment can potentially make astronauts more resilient in space psychologically and physiologically, ensuring the success of long-term space missions.
To address these challenges, researchers are exploring new methods of food production and preparation for long-term space missions. Small-scale aseptic food production systems using hydroponic, aeroponic, and substrate culture techniques have been developed to provide fresh fruits and vegetables for astronauts. Closed-looped small-scale food production systems, such as the “salad machine” and the Passive Orbital Nutrient Delivery System (PONDS), have also been developed to grow crops in space. However, food production and preparation in microgravity present unique challenges, such as the vulnerability of fresh fruits and vegetables to microbial contamination and the difficulty of using common cooking methods. Solutions to these challenges are needed to ensure that astronauts have access to safe and nutritious food during long-term space missions.
The use of nature-based regenerative life support systems that enable a self-sufficient lifestyle is critical for helping astronauts better adapt to the adverse conditions of the space environment. Incorporating nature-based environments within a landscape-scale space habitat can potentially make astronauts more resilient psychologically and physiologically to better ensure the success of long-term space missions.
Cultivating plants in space has been found to have positive psychological benefits for the crew. Further scientific investigation is needed to better understand the crew-plant interaction and the effect of growing one’s own food on the psychological well-being and performance of the crew. As future space missions to Mars will take more time than most astronauts have continuously spent in space, understanding the psychological benefits of cultivating plants in confined areas is required.
Overall, plant growth systems in space have come a long way since the early exploratory systems. With advancements in technology and increasing knowledge of plant behavior in the spaceflight environment, future plant growth systems will continue to improve and play an essential role in sustainable life support systems in space.
40 Years of Space Plant Growth Systems
Besides the need for sustainable solutions for nutrition in space, another crucial area of focus is crop cultivation on extraterrestrial surfaces. This includes growing crops on the moon, Mars, and other celestial bodies. To prepare for this, researchers have selected eight crop species that can meet the nutritional needs of space travelers based on the three macronutrients: rice, potato, sweet potato, soybean, lettuce, tomato, cucumbers, and strawberries. These crops were chosen for their ability to grow in low gravity and with minimal resources, such as water and oxygen. To increase crop yields per space, researchers are also utilizing genetically modified products and gene editing, as well as considering light, space, and electric energy use efficiencies.
The cultivation of plants in space has been an essential part of developing sustainable life support systems for human space exploration. Efforts to grow higher plants and study their behavior in the spaceflight environment have been ongoing since the early days of space exploration. These efforts have included free-flyer experiments, short-duration crewed missions, and long-duration missions conducted in various space stations, such as Salyut, Mir, and the International Space Station (ISS).
In particular, plant growth experiments have been an important part of each space station program since the first space station, Salyut 1, was launched by the Soviet Union. Early plant growth systems were exploratory in nature, focusing on fundamental investigations related to the effect of the spaceflight environment on plant growth and technology development associated with providing an appropriately controlled environment on orbit.
Over the past 40 years, more than 20 different plant growth systems have been utilized to grow over 40 different plant species in space. These systems have included small chambers used to study plant behavior and development under reduced gravity and closed environments, as well as larger chambers designed for basic plant science and food production.
One of the challenges of growing crops in space is the limited availability of resources. To address this, studies are being conducted to establish waste treatment technology and complete substance circulation. These studies will produce results useful on Earth as well.
Another major challenge of growing plants in space is irrigation and root zone moisture control. Unlike terrestrial or future planetary surface systems, where gravity can be used to help drain irrigation water and aid in water recovery, controlling water movement and distribution in microgravity is more challenging and can result in flooding and anoxia. Nutrient delivery systems have also been a challenge, with microgravity-based systems requiring active nutrient delivery systems to ensure reliable irrigation and nutrient provision.
Atmosphere management is another important aspect of plant growth systems, with early systems relying on ventilation with cabin air to remove excess heat produced by fluorescent lamps. Later systems incorporated independent atmosphere management systems that included temperature and humidity control and, to some degree, carbon dioxide regulation. Trace gas control in the form of an ethylene scrubber was also incorporated in some systems.
The development of the illumination system for plant growth chambers can be divided into two eras: the pre-LED era and the LED era. LED systems have become increasingly popular due to their high efficiency, small size, controllability, and variable spectrum. The effects of different light mixtures on plant growth and the production of secondary ingredients such as vitamins and antioxidants have also been studied.
As extraterrestrial plant growth systems get larger, means of automation need to be investigated to reduce the required crew time to maintain the system. While atmospheric and illumination systems are already widely automated, the watering of plants and the adjustments of the nutrient solution are still mostly performed by the crew. Plant health monitoring is another important area to improve automation. Until now, such tasks have been primarily performed by the crew, which rarely comprises a horticulturist, and communicated to plant cultivation experts on Earth for evaluation. Systems to automatically detect plant stress and other issues, such as thermal and fluorescent imaging, should be considered for future chamber designs.
Another important element for realizing extraterrestrial farming is saving space, energy, and resources. Studies are being performed assuming 1/6 of the gravity on the Earth’s surface and minimizing the use of substances collected from the lunar surface, such as water mined from polar regions of the moon, oxygen, phosphorus, and potassium. Electricity will be available from solar power generation. As little waste as possible should be discharged, and recycling should be maximized. Researchers are also utilizing plant factories with artificial light on the lunar farm, which can maintain a high degree of closure to the external environment and select potential candidate crops to be cultivated on the moon. Rice plants can be cultivated with hydroponic techniques at high efficiency.
In addition to crop cultivation, researchers are also exploring the use of other food sources in space. For example, the EDEN ISS project involves cultivating leafy greens, tomatoes, cucumbers, bell peppers, kohlrabi, and radish in a greenhouse in Antarctica. The project, which involves 8 countries and is an EU project, is testing controlled environment agriculture using artificial illumination and soiless irrigation methods such as aeroponics and enhanced atmosphere control systems. They managed to cultivate fresh food in an environment where the temperature can go below -40 degrees. The microbial investigation revealed that the microbial load of crops was 1000 times smaller than crops from the supermarket. The psychological investigation showed encouraging results after 7 months of isolation.
Advanced closed-loop life support systems, such as the one developed by the German Aerospace Center, which uses algae-powered photobioreactors to provide continuous and breathable air in space by converting astronauts’ breath and sunlight into oxygen and food, could provide up to 30% of the food that an astronaut needs.
Another important aspect of space nutrition is the recycling of materials. An average human being intakes 618 g of food per day and ejects 109 g of solid waste. They breathe 836 g of oxygen and produce 1000 g of CO2. It is difficult to carry all the necessary food to the Moon from Earth. Therefore, the equipment that conducts food production, air and water cleaning, and material recycling is essential. Plants can produce food, oxygen, and clean water while reducing CO2. Researchers are exploring the use of peanuts, carrots, sweet potato leaves, roots, and stems as potential food candidates for space cultivation. These foods contain a variety of nutrients, including protein, vitamin C, K, carotene, and calcium.
Researchers are also exploring animal food ingredients for space nutrition. Fish can be farmed in aquaponics together with sweet potatoes (e.g. tilapia fish). Loach fish (Japanese traditional fish) can also be used. Other co-cultures are mushrooms, microalgae and plants. Shiitake mushrooms and lettuce have similar respiration rates and can support each other (mushrooms consume oxygen). Co-cultivation with microalgae does not influence growth of other vegetables but they can contribute useful components for supporting human health
Microgravity poses a significant challenge to food production, and special attention must be paid to the effects of gravity, light, atmosphere, soil, and radiation on plant growth in regenerative life support systems. In-space manufacturing and the generation of artificial gravity will be important to enable the use of more ecosystem-like closed-loop life support systems without increasing the safety risks associated with a higher likelihood of microbial contamination in microgravity. Therefore, it is necessary to undertake a modular approach to increase the size of transit space habitats for long-term space missions.
Various crops have been successfully grown in microgravity, including onions, cucumbers, radishes, tomatoes, strawberries, lettuce, wheat, peanuts, soybeans, mizuna, pea, and other food crops. However, due to restricted metal availability and nutrient enrichment, Martian regolith cannot support plant growth without nutrient supplementation. Even with supplementation, none of the three available Martian Regolith Simulants (MRSs) can support plant growth. Similarly, the lunar regolith cannot support plant growth without addressing issues associated with potentially toxic elements, pH, nutrient availability, air and fluid movement parameters, and its cation exchange capacity.
To support food production on Mars and the Moon, closed-loop life-support systems will be necessary. The German Aerospace Center has developed an advanced closed-loop life support system that uses algae-powered photobioreactors to provide continuous and breathable air in space by converting astronauts’ breath and sunlight into oxygen and food. This system could provide about 30% of the food that an astronaut needs. The concept of the human habitat is based on a symbiotic relationship between humans and plants. Edible plants consume carbon dioxide and release the oxygen that humans need. In return, human waste and non-biodegradable plant matter energy provide nutrients for plant growth. These plants can also provide medicine. However, the effects of gravity, light, atmosphere, soil, and radiation on the growth capacity of plants in this regenerative life support system remain largely unknown.
Current Experimentations on Earth: Biomass Production of the EDEN ISS Space Greenhouse in Antarctica
The EDEN ISS greenhouse, located near the German Neumayer III station in Antarctica, is a state-of-the-art space-analog test facility designed to produce food during human space missions. Cultivating plants in space has been a necessary step to reduce resupply mass from Earth and thus long-term mission costs. Experiments in growing plants in a closed controlled environment on Earth have been conducted for decades by several research teams, including NASA’s Biomass Production Chamber, the Russian BIOS facilities, the Japanese Closed Ecology Experimental Facility, and the Chinese Lunar Palace 1.
Unlike other facilities that were built to conduct research on humans living in a closed loop life support system, EDEN ISS focuses on cultivating plants in controlled conditions, testing the necessary hardware and investigating microbiology, food quality, and safety aspects. The EDEN ISS Mobile Test Facility (MTF) was set up in Antarctica to achieve these goals. The MTF consists of two customized 20-foot high cube shipping containers placed on top of a raised platform located approximately 400 meters south of Neumayer III.
The MTF uses six different subsystems to cultivate plants in a controlled environment. The nutrient delivery subsystem adjusts the irrigation water’s pH and EC value, while the atmosphere management subsystem regulates the temperature, humidity, and CO2 concentration. The thermal control subsystem removes excess heat from the MTF and provides a cool fluid for condensation of the humidity produced by the plants. The illumination control subsystem consists of 42 fluid-cooled LED fixtures integrated into the FEG. The power distribution subsystem provides electrical energy to all subsystems of the MTF, and the control and data handling subsystem consists of a set of independent programmable logic controllers which receive information from a wide range of sensors.
The novel aspect of the EDEN ISS project is its approach to work with a compromise climate in which all crops are grown simultaneously. This is more realistic for near-term space greenhouses as compared to studies where each crop has its optimized climate. Despite not having the optimal climate for each crop, the food production of the MTF in the 2018 season was higher than expected. In 2018, for the first time, a comprehensive set of measurements were performed in an analog space greenhouse.
The cultivated crops are organized into five categories: lettuce, leafy greens, herbs, fruit crops, and tuber crops. During the 286-day operational phase in 2018, the EDEN ISS MTF produced 268 kg of fresh edible biomass. The SPGFC mainly produced lettuce (32% of total fresh edible biomass) and cucumber (41%) and only small amounts of herbs (6%), tomato (4%), and other crops (17%). Whereas the distribution in EDEN ISS in 2018 was 21% lettuce, 18% leafy greens, 25% cucumber, 5% herbs, 14% tomato, 10% tuber vegetables, and 7% other crops. Since cucumber has the highest production rate per unit area and time, the higher ratio of cucumber in the SPFGC harvest can explain the better overall production rate of fresh edible biomass compared to EDEN ISS to some degree.
When comparing the results from Antarctica with the experiments conducted in plant growth chambers in Europe, the yield per unit time and cultivation area of lettuce was higher in Antarctica than in the experiments in Europe. The yield of the red mustard frizzy lizzy, Swiss chard, parsley, and chives was better in the plant growth chambers in Europe than in Antarctica, but the plant density in those experiments was much higher. The yield of lettuce was better than some other experiments, but only half as good as the values achieved by the BPC.
During the 286-day operational phase in 2018, the EDEN ISS MTF produced 268 kg of fresh edible biomass, which is a good result for the first year of operation. The SPGFC mainly produced lettuce (32% of total fresh edible biomass) and cucumber (41%) and only small amounts of herbs (6%), tomato (4%), and other crops (17%). Whereas the distribution in EDEN ISS in 2018 was 21% lettuce, 18% leafy greens, 25% cucumber, 5% herbs, 14% tomato, 10% tuber vegetables, and 7% other crops. These results indicate that the EDEN ISS MTF successfully cultivated a diverse range of crops in its controlled environment.
The technologies required to cultivate plants in a controlled environment are arranged in six different subsystems, including the nutrient delivery subsystem, the atmosphere management subsystem, the thermal control subsystem, the illumination control subsystem, the power distribution subsystem, and the control and data handling subsystem. The nutrient delivery subsystem adjusts the irrigation water’s pH and EC value to provide a dedicated nutrient solution for each crop. The atmosphere management subsystem regulates the temperature, humidity, and CO2 concentration, and the air flow is filtered to ensure the safety of the crops. The thermal control subsystem removes excess heat from the MTF and provides a cool fluid for condensation of the humidity produced by the plants. The illumination control subsystem consists of 42 fluid-cooled LED fixtures that provide the required light spectrum for each crop. The power distribution subsystem provides electrical energy to all subsystems of the MTF. The control and data handling subsystem consists of a set of independently programmable logic controllers that receive information from a wide range of sensors and send system telemetry to the mission control center in Bremen, Germany.
The novel aspect of the EDEN ISS project is its approach to work with a compromise climate in which all crops are grown simultaneously, which is more realistic for near-term space greenhouses as compared to studies where each crop has its own optimized climate. Despite not having the optimal climate for each crop, the food production of the MTF in the 2018 season was higher than expected. This success can be attributed to the MTF’s unique location, the use of cutting-edge technologies, and the expertise of the researchers and operators involved in the project. The high yield of cucumber and lettuce can be explained by the absence of seasonal temperature and illumination changes which affect conventional greenhouse farming. Overall, the EDEN ISS MTF demonstrated that it is possible to cultivate a diverse range of crops in a controlled environment, which is a necessary step towards sustainable food production during future long-duration human space missions.
Long-term Nutrition in Space: Conclusions
After examining various studies and reports, it is evident that there is a growing need for sustainable and self-sufficient food production systems for long-term space missions. Resupplying food from Earth is cost-prohibitive, and packaged food cannot meet the nutritional and psychological needs of astronauts during long-term space missions. Therefore, developing closed-loop life-support systems that rely on self-sufficient bioregenerative systems to produce fresh foods is necessary.
While many crops can be successfully grown in microgravity, such as onions, cucumbers, and radishes, closed-loop life-support systems will be necessary to support food production on Mars and the Moon. These systems can be implemented in situ on the Moon or Mars or in upscaled space habitats with artificial gravity.
Furthermore, it is crucial to produce fresh food with distinctive, original flavors to increase appetite, promote place attachment from biophilia, and help astronauts better adapt to the adverse conditions of the space environment. The use of a nature-based regenerative life support system and incorporating nature-based environments within a landscape-scale space habitat can potentially make astronauts more resilient in space, psychologically and physiologically, to ensure the success of long-term space missions.
In conclusion, developing sustainable and self-sufficient food production systems for long-term space missions is critical for providing a diverse range of nutrients while working within the limited payload threshold allowed by each space flight. As technology advances, closed-loop life-support systems, artificial gravity, and in-space manufacturing will become increasingly more feasible, allowing for the development of more complex and comprehensive systems that can support astronauts’ food and nutritional needs during long-term space missions.
Tang et al. (2022). Long-Term Space Nutrition: A Scoping Review. Nutrients 14, 194.
Zabel et al. (2020). Biomass Production of the EDEN ISS Space Greenhouse in Antarctica During the 2018 Experiment Phase. Front. Plant Sci. 11:656.
Zabel et al. (2016). Review and analysis of over 40 years of space plant growth systems. Life Sciences in Space Research 10:1-16.
Eden International Space Station. Available at: www.eden-iss.net
 A Vegetable Production Unit for Long Duration Space Missions: https://www.sae.org/publications/technical-papers/content/901280/?src=2009-01-2381.
 The PONDS was developed for flight in NASA’s Vegetable Production System (Veggie) facility by Redwire, with collaboration from Tupperware Brands. It can grow a wide variety of plants in space, and requires far less monitoring and maintenance time from flight crews than other plant growth devices.
 Regolith is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons. (Source: Wikipedia)