Future of astronaut nutrition: Trends that could re-define surviving in space

The NASA Artemis I launch is an important step towards making it possible for people to go farther and spend more time in space than ever before. Future Artemis missions aim to send crews to Mars and the Moon, a journey that will take up to three years in total.

A crucial question posed to scientists before these missions is asking what the astronauts will eat, to not only fulfil their daily nutritional intake, but also to satisfy them. As surviving on protein bars and vitamins for years on end certainly doesn’t sound the least bit appealing – plants, with their incredible capacity to transform light, water, and carbon dioxide into food, serve as the foundation of life on Earth and are the obvious choice to feed people in space.

The challenges of a space garden

Astronauts have consumed space radish, chilli peppers, and lettuce on the International Space Station, but cultivating a successful space garden comes with a lot of difficulties.

Space environments are CO2-rich, lack soil microbes, have altered gravity, are exposed to potentially harmful solar radiation, and need to use recycled, high-salt water. Plants require a redesign in order to flourish in space and provide the entire range of nutrients necessary for human health. Imagine going to your space garden and selecting a ripe juicy tomato and a fiery chilli to add to your tacos after months of freeze-dried or prepared space cuisine.

Adding fresh produce has been a good way to improve astronaut wellbeing, supply essential vitamins and minerals, and add flavour, especially as low-gravity environments affect our taste and smell. Future long-duration space missions must have a sustainable food source to prevent astronauts from becoming “food fatigued,” being undernourished, and losing weight.

Currently, space plants are cultivated in sealed containers with LED lights that use little energy, a porous clay “soil” that provides water, nutrients, and oxygen to the roots, and sophisticated sensors and cameras that keep an eye on the health of the plants.

Plants did not evolve to grow in a box and use energy in readiness for changes in light, temperature and disease, limiting full growth potential. So, we can modify plant genetics to generate “pick and eat” food crops with a faster rate of growth, like tomato, carrot, spinach, and strawberry, that are created to perform to their fullest in enclosed, regulated conditions.

A sustainable space plant future

Future systems for growing plants in space must be sustainable. This means recycling nutrients and water alongside other systems in a space station or outpost on the moon or mars. All plant materials must be used as food, composted, or made into useful items like plastic and fuel. Plants may obtain nutrients from human waste, including urine, but they also need to be able to tolerate the salty water. One plant might be well adapted for the job.

Participants of the Tasting Australia presented by RAA event, ‘Astro Thai’, learnt of the capability of the humble duckweed plant. Duckweed can survive in recycled water and have zero waste, with the entire plant being edible, means that even if it may not be available at your local grocery store, this very quick growing plant could be in all space gardens.

Duckweed can be continuously harvested, grows to twice its original size in two days, and is rich in protein, minerals, nutrients, and antioxidants. Only a few vital components, like vitamin B12/D, are absent, meaning it is almost a trustworthy basic supply for full human nutrition.

Scrumptious duckweed delicacies

At the Tasting Australia event, Soi 38 executive chef, Terry Intarakhamhaeng, combined his Thai heritage and knowledge of cooking to show how duckweed could be used in a multitude of delicacies. On the innovative menu were duckweed cake with a soy and vinegar sauce, Thai omelette with duckweed and sriracha mayo and Gaeng Om pork scotch and duckweed.

All three dishes were well received in the sold-out event, further cementing duckweed as a versatile, nutrition rich and appetising food option for space exploration. Recent scientific developments in gene regulation, genome editing, and nutrient analysis can be used to modify duckweed and other plants for optimum growth, low waste, and full nutrition.

By using this process, new plants can be created that have soluble fibre for better gastrointestinal and cardiovascular health, nutritious plant oils for an energy boost, and proteins that are properly balanced for human digestion and utilisation. The pursuit of space exploration has given rise to countless innovations that we now take for granted.

We anticipate that the innovations to help people survive in space will have vital sustainability perks for Earth, particularly for the provision of food and biomaterials on demand.

Experts from all over, including plant biologists, engineers, food chemists, psychologists, sensory experts, nutritionists, ethicists, and legal experts, are cooperating to achieve these two objectives.Humanity is about to reach a new milestone in its development; rather than just gazing up at the stars in awe, we will soon be journeying to places outside of our atmosphere and sowing the seeds of a new way of life both here on Earth and beyond.

Kim Johnson is a Senior lecturer, La Trobe University, Harvey Millar is a Professor and ARC Australian Laureate Fellow at The University of Western Australia and Matthew Gilliham is a Professor in Plant Molecular Physiology, University of Adelaide.