“It appears a colonization of the moon could become a reality,” state Cornell University researchers R. W. Langhans and D. R. Dreesen hopefully in 1988 – and it would only be a “true colony [if] food could be produced” (Langhans and Dreesen, 1988).
The quest for interplanetary travel and colonization is one that, in the modern day, remains far-fetched and distant. While governments and research organizations have landed robots on Mars and mapped much of the Moon, the dream of a permanent, or at least self-sustaining, Moon base is still far off in the distance. One of the largest barriers to that dream is the challenge of growing food in space.
Image Credit: NASA/ISS
“The opportunities are exciting and almost unlimited in scope” (Langhans and Dreesen, 1988)
Plant growth in space is challenging for a number of reasons due not only to the harsh conditions of space, but also the harsh design and engineering conditions of the spacecraft. Plants in space need to be able to survive radiation, microgravity, and low-light conditions, while also being physically compact, non-disruptive to the spacecraft’s oxygen and carbon-dioxide levels, and unable to produce excess waste, toxins, and dangerous microbes (Musgrave, 2008; Langhans and Dreesen, 1988; Reed and Vanden Bosch, 2023). Beyond those requirements, these compact space-grown plants must provide all the essential nutrients required for a human diet in the absence of animal products and larger plant products like large fruits (Langhans and Dreesen, 1988).
While difficult, growing plants in space is extremely rewarding. NASA has determined that only eight species of plants – wheat, rice, white potato, sweet potato, soy bean, peanut, lettuce, and sugar beet – contain all the essential elements, carbohydrates, oils, and amino acids for a balanced human diet (Langhans and Dreesen, 1988). Vitamins, while not fully covered by these eight species of plants, can be supplemented for shorter missions, although they break down when prepackaged for longer ones (Langhans and Dreesen, 1988; and NASA, 2023). In addition, plants have been shown to be positively correlated with psychological well-being on Earth and in space (NASA, 2023). Plants then, are not only beneficial for the astronauts physical health, but their mental health too.
Currently, NASA employs two growth habitats: the Vegetable Production System (nicknamed Veggie) and the Advanced Plant Habitat (APH) (NASA, 2023). Both Veggie and the APH use enclosed microbiomes with simulated radiance from LED lights and carefully controlled gas content, temperature, and moisture levels (NASA, 2023). While not all eight of the ideal plants identified in 1988 have been successfully grown, the advancements of Veggie, APH and other new technologies shine a light on a hopeful future of plant-filled space exploration.
Credits
Langhans, R. W., & Dreesen, D. R. (1988). Challenges to plant growing in space. HortScience, 23(2), 286-293.
Musgrave, M. E. (2008). Growing plants in space. CABI Reviews. https://doi.org/10.1079/pavsnnr20072065
NASA. (2023, December 8). Growing plants in space. NASA. https://www.nasa.gov/exploration-research-and-technology/growing-plants-in-space/
Reed, D. W., & Vanden Bosch, C. A. (2023). Engineering perspectives of growing plants in space. Journal of the Indian Institute of Science, 103(3), 797–805. https://doi.org/10.1007/s41745-023-00369-6
