Two summers ago I was working for the USDA doing a soil survey at Glacier National Park. While in the field, I told the soil scientists I was working for about our aquaponics project at the University of Montana Dining Services, SPACE 200. The next summer, they told their new field assistant Carmel Johnston about our project. Johnston asked the USDA soils crew to connect us because she had hoped to bring an aquaponics system with her on her next project. Johnston was selected to be commander of Hi-SEAS, a yearlong Mars simulation funded by NASA through the University of Hawaii. The Hi-SEAS mission is to study the physiological and psychological effects of isolation on a small group of space settlers. Being a soil scientist and gardener, Johnston had hopes of bringing an aquaponics system into the simulation for her and her crew to grow fresh vegetable during their year of isolation. She had a hunch that having plants on board would confer a positive effect on crew morale as well as her own. When she asked if we would be interested in building an aquaponics system for the Hi-SEAS mission, we were absolutely thrilled to help her out.
X-30 system ready to assemble
Within a week we met up with Johnston to discuss experimental design and the constraints that she would be facing in the Hi-SEAS dome. We decided to build 4 small 30 gallon systems (the x-30s); 2 would use fish effluent and 2 would use human urine as a nutrient source. Unfortunately, there were problems getting fish for the systems due to Hawaii’s strict regulations regarding live fish transport. In the end, the crew was only able to use human urine as a nutrient source, which actually had decent results.
Besides not being able to use the fish we had planned for in our experimental design, there were energy issues to contend with as well. We knew going in that power would be limited, so we selected very low energy usage LED lights. Johnston coped with this limitation by selecting low light requiring plants to grow in the systems. However, the power available to the LED lights was through solar DC power, and therefore was too inconsistent to meet the needs of the plants. Johnson dealt with this by keeping 2 of the systems near a window to receive to available sunlight from outside.
Chard and kale under LED grow lights
Ultimately, Johnston and her crew were able to successfully grow peas and chard, although at low production levels. Although the systems were not as productive as they would have been if there were fewer limitations, the crew reported that working together on the project had value in terms of psychological benefits. The psychological effects of the astronaut diet were addressed in depth when the Hi-SEAS crew was interviewed for a recent podcast on Hidden Brain. They reported that much of their time is spent thinking about food because their options are so limited. Previous research has shown that astronauts often become bored of their limited food choices and then stop eating as much as they need for optimal health. The theory here is that humans are foraging omnivores and we are evolved to desire a certain level of variety that helps to ensure that we consume the diverse set of nutrients we require. For the crew of Hi-SEAS, having the novelty of fresh vegetables, even if only on special occasions, really helped them feel excited about meals during their year of living on preserved astronaut food.
Snap peas growing from one of our experimental systems
Healthy looking kale
Galactic Farms was very excited to have been able to participate in the Hi-SEAS project. It was a lucky happenstance that we connected with Carmel Johnston through our USDA friends. Our luck continued when one of Johnston’s crew members, astrobiologist Cyprien Verseux, sent us a very interesting review article he and his colleagues wrote on the potential for using cyanobacteria as a way of extracting nutrients from undeveloped rock dust (regolith) found on Mars. This seemed like a pretty interesting thing to look into and inspired us to start a cyanobacteria culture at Galactic Farms. Furthermore, the Verseux paper was the foundation for our submission to the Mars City Design competition, where we were able to place first in the agricultural section of the contest. For more details on this project, click the link:
コメント