Hydroponic Plant Cultivation on a Lunar Base Using Nutrient Sources from Human Waste

Resource utilization will be essential when humans establish a permanent Lunar base. Human waste is among the resources where nutrient element and water can be reused. Regenerative systems are needed to recycle and reuse resources providing astronaut with component of the air that they breath, water to drink and food to eat. Using plants cultivated in water-based substrates (hydroponics) is regarded as key element of the regenerative systems. In the LunarPlant project fundamental knowledge, methods and technologies will be developed within hydroponic plant cultivation to enable reuse of nutrients from human waste. As part of this work nutrient solution based on human waste will be mineralized and characterized. Plant responses and tolerance to the nutrient solution will be analyzed. Plant root support of regolith and 3D-oriented cellulose foams will be characterized and tested. An important aspect will be analyzing the nutritional value and food safety of the plants. Lettuce will be the main model plant, but other crops will also be studied (red-beet, kale, spinach and cabbage). The LunarPlant project bring together an interdisciplinary and international team of scientists: • CIRiS has the project management and is responsible for plant hydroponic cultivation and analyzing the plant responses. • IBP SB RAS will develop the human waste mineralization regime and provide the nutrient solution for plant cultivation. • NTNU is responsible for food safety evaluation and analyzing the nutritional value of the plants. • SINTEF is responsible for the work on the root support substrate and the project dissemination. • VTT will design and manufacture the 3D cellulose-based foam to be used as root support. The science team, including PhD and Postdoc, will develop knowledge, materials and technology leading to a significant step forward within closed life support systems for human space exploration and resource utilization of nutrient elements on Earth.

Closed regenerative life support systems are developed to support astronauts that will stay long term in space, providing them with food, oxygen, and pure water. Limitation of resources that can be transported and waste management calls for a recycling and reuse strategy, and careful planning of cargo when they travel. In this project Norwegian researchers with over a decade of experience with plant experiments on the International Space Station (ISS) and ground research with ESA. Novel plant production technological concepts will be developed in a joint comprehensive R&D project incorporating several development phases. Phase I is a scientific research stage to evaluate performance of lunar regolith simulant and cellulose substrate for their potential to be used as root support infrastructure in hydroponics as well as gaining fundamental knowledge on plant salt stress and tolerance. Phase II is a scientific research stage to establish balanced nutrient mediums capable of supporting their growth and best productivity. Research activities will reveal mechanisms and strategies relevant to achieving highest production yields and nutritional values of the plants. Knowledge, results, and generated technical data will be transferred and disseminated between project partners to be used to guide experimental development in later development stages. Phase III will cover hydroponic cultivation experiments with lettuce and halophytic plants. Quality testing on the plants with regard to food safety and nutritional values will be performed. Phase IV of the project will provide a technology evaluation with regard to its potential use for plant cultivation on a lunar base and terrestrial applications.