Design of an On Ground Experimental Growth Unit (OGEGU) for space applications

The capacity of producing fresh food meeting crew's nutritional requirements is an essential need for long-term planetary missions. To this end, the European Space Agency (ESA) has commissioned a feasibility study of Food Production Units (FPU) for their application in microgravity, transit and planetary environments. This paper describes the "On Ground Experimental Growth Unit" (OGEGU), which is a ground-based, closed loop FPU concept for plant cultivation, conceived as a first approach in the adaptation of food production systems to Space. The OGEGU design is based on state-of-the-art greenhouse technology. Nine OGEGU key subsystems (external structure, irrigation, lighting, plant support structure, crop handling, crop and seed preservation, climate control, water and nutrient delivery, and waste management) are discussed and implementation options are proposed considering constraints such as power, mass or volume imposed by their eventual use in Space. Potential OGEGU topologies are also outlined. OGEGU subsystems are then dimensioned to accommodate the cultivation of selected crops that deliver up to 40% of the diet requirements for a six member crew. For comparison purposes, two groups with four different crops requiring distinct cultivation conditions in terms of surface and volume are considered. Finally, the resulting OGEGU designs are evaluated and traded-off using the Equivalent System Mass methodology. Copyright © 2005 SAE Internationa