The critical technologies that will enable remote ‘off-world’ habitation include propulsion systems – which are well advanced – and life support technology, such as the supply of adequate nutrition, which are early in their development cycle. Unlike water, oxygen and fuel, food is not available for harvest on the Moon or Mars and re-supply of resources from Earth is not a viable option, due to the current mass and volume restrictions for space travel. Even if enough food could be sent in advance, keeping essential vitamins and nutrients stable for longer periods of time, five or more years, is not yet achievable. Furthermore, the challenge of providing an adequate and varied diet without fresh produce leads to menu fatigue and resulting weight loss. Compounded by the additional requirements of the human body under the stresses that space brings, including altered gravity and increased radiation, all of this will mean a drop off in performance in individuals who need to be highly alert. Ultimately, these factors make providing a nutritious, varied food supply to sustain physical and mental wellbeing for long-term human space habitation one of the greatest obstacles for mission planners.

Space: the ideal laboratory

Two camps of opinion arise when the prospect of space settlement and its challenges are aired. One camp echo the view of monarch-in-waiting Prince William, who recently stated that ‘we should repair this planet and not find the next’, when launching his Earthshot prize for 50 solutions to the world’s greatest environmental problems by 2030. The second camp sees that an attempt to achieve the currently impossible – the moonshot of the 21st Century (humans living on Mars) – will unlock innovation previously unimagined.

It is our view that Space research will help us achieve sustainability on this planet and is not in conflict with sustainability research for Earth. Space and Mars missions will necessitate sustainable food production in a closed loop system – with near zero waste. Because of this, space proves to be the ideal laboratory for innovative technologies, providing new opportunities for achieving sustainability on Earth. The catalogue of space-assisted translation for Earth industries is long and touches upon everyday items we have come to depend upon such as LED lighting, solar cells, water purification and food preservation systems. The diet of astronauts on the International Space Station consists of pre-packaged, often dehydrated food, with occasional supplementation of fresh produce from Earth. The growth of plants in space is only at the experimental scale, and the produce have rarely been eaten. A focus on food and material production, using plants and the processing and longer-term storage of food in space could lead to a range of future innovations. There will be unique space conditions that will need to be overcome for the growth of plants and production of food off-Earth, particularly microgravity and extreme high carbon dioxide concentrations. However, the overall sustainability challenge of producing nutritious, palatable, digestible, and food shelf-stable foods with minimal energy and water input in space are similar to those faced on Earth. Resulting applications in areas will be as diverse as the rapidly growing global controlled environmental agriculture (CEA) sector – >20% per annum (1), the advanced manufacture of food and pharmaceutical products, and the production of tailored nutritional products for a wide variety of settings and consumer groups, including aged care facilities (2). Such research aligns seamlessly with the national priorities of the Advanced Manufacturing Growth Centre (AMGC) (3), the Food and Agribusiness Growth Centre (FIAL) (2), and the MedTech and Pharma Growth Centre (MTPConnect) (4) to boost commercial opportunities in these areas. Space research therefore is a significant market opportunity that will increase in importance over the upcoming years. It would be remiss to not deploy and take advantage of the enabling technology needed to achieve this here on Earth long before humans step onto the Mars surface 20 plus years from now.

Australia – an agricultural heavyweight

Australia is in a strategic position to move into space horticulture, due an ideal combination of knowledge and skills in many different areas. In particular, Australian researchers in the broad category of agriculture (including plant-based food production) are world leading, with many more universities featuring in the top 50 globally ranked universities than for any other discipline (5). Despite many challenges in production constraints, global connectivity and market access, Australia produces enough food for almost three times its population, with clear success stories in food and beverage innovation in past decades. Australian primary producers are among the world’s most innovative, leading the way in efficient water and nitrogen use, and producing stress tolerant crops. Furthermore, targets set by the Australian government and the Australian Space Agency, for a $200 billion agricultural industry and a $12 billion space economy respectively, allow for Australia to contribute a globally significant effort in this research arena (6,7). The innovation required to provide the nutrition and biomaterials to sustain long-term space habitation, and to deploy this technology here on Earth to improve sustainability, is one such area where researchers in Australia are putting their efforts. Here, Australia can claim to have the critical mass and is capable of providing global leadership.

Plants4Space

Plants are the ultimate base material for food production in Space due to their autotrophic nature. Both plants and photosynthetic microorganisms can support life requiring nothing but carbon dioxide, light, water, and a minimal set of nutrients to produce sustenance and oxygen required for humans. In return, we use the carbon fixed by plants as energy and complete the circle by respiring carbon dioxide. Higher plants have the added benefit of an intricate metabolism, and ability to compartmentalise that metabolism in different cellular compartments or tissues, that provides a platform to produce highly complex molecules adding flavours, nutrients, and even biomaterials such as plastics. Heterotrophic bacterial, yeast, cell and insect-based systems will also play a role in space, particularly in food and waste processing, but are less sustainable and less suitable for a completely closed food production system due to their requirement for plant derived carbon sources. The need for plants in space coincides with growing global demand for plant-based food on Earth, driven by consumer concerns of sustainability, health, animal welfare and the rise of flexitarian and vegan diets. Achieving a wide range of plant-based food products, however, is not without its challenges, including the problems presented by the low water solubility, taste and texture of plant proteins. The growth and development of plant-based foods therefore presents a range of scientific and engineering challenges. A unique collaboration of researchers at the Universities of Adelaide, La Trobe, Melbourne and Western Australia, with world leading institutes and space agencies around the world have formed a cluster of expertise in Plants4Space. This convergence of previously disparate disciplines will bring together the skills needed to address these challenges to achieve long-term human space habitation. The research platform brings together molecular plant sciences, advanced medicinal agriculture, plant physiology and biotechnology, innovative food and bioprocessing, sensory sciences and psychology, nutrition, systems and process engineering, and law.

The main ambitions for Plants4Space include:

• The use of new technologies to produce nutrient rich, highly efficient plants, with near zerowaste suitable for rapid growth in controlled environments
• The fortification of plant-based foods into a complete nutritional source (including nutrients sourced traditionally from animal sources) using modern gene technologies
• The production of spaceready functional materials, pharmaceuticals and foods, and the translation of these into Earth markets
• Training a new generation of plant and food researchers, and industry professionals.

These main ambitions will contribute to the delivery of new plant products with improved stability to assist with global food distribution. They will allow the production of food closer to demand and the opening of new markets. Ultimately, they will decrease the carbon footprint of production, if coupled to renewable power sources. They will also provide new insights into plant ingredient functionality and the development of innovative industrial technologies (at scale and miniaturised) to make a range of palatable, novel plant-based ingredients and products. Yoghurtlike gels, semi-solids (‘cheese’), solids (striated products resembling meat), or novel 3D-printed formats are worthy targets of investigation that would allow a variety of products that could help to fight menu fatigue. Plants4Space aims to develop new methodologies to predict the sensory and digestive properties of raw and processed plant foods, in order to reduce the need for sensory panels. This will reduce cost, waste, and time-to-market, providing significant economic benefits in product and process development. Lastly, the research cluster will develop a greater understanding of the link between food formulation and gastrointestinal behaviour, which will allow food nutrition, transit, and digestion to inform product design, benefitting consumer health including the growing aged care market. This research will provide breakthroughs in the emergent field of plant processing, sustainability and food production. These advances will firmly establish Australian competitiveness as a leader in highvalue, low-input and sustainable agricultural production and greatly support that ‘moonshot’ of the 21^st Century – long term space habitation.

Plants4Space are searching for industry professionals who would like to partner at the junction of plant production and food engineering to pave the way to new, plant-based food solutions that improve nutrition and physical health for consumers in rapidly growing vegan, vegetarian, and plant-based markets.

References

1. Global Market Insights. (2021) Vertical Farming Market Size… & Forecast, 2021–2027.
2. FIAL. (2020) Sector Competitiveness Plan.
3. AMGC. (2020) Making it happen: The Australian Government’s modern manufacturing strategy
4. MTPConnect. (2020) Sector Competitiveness Plan
5. AWRU: http://www.shanghairanking.com/
6. FIAL. (2020) Capturing the prize: The A$200 billion opportunity in 2030 for the Australian food and agribusiness sector.
7. ASA. (2019) Advancing Space: Australian Civil Space Strategy 2019–2028

For more information on this consortium and to reach out for collaboration see www.plants4space.com.