Astro GardenTM Aeroponic Plant Growth System Design Evolution

By providing dietary nutrients as well as unburdening physiochemical life support equipment, Hybrid Life Support Systems (HLSS) can be an attractive option for longer duration space exploration such as Mars transit missions. State of the art microgravity plant nutrient delivery utilizes a physical media in which the plant roots grow (e.g., clay-based arcillite). This added media increases mass to orbit necessary for growing plants in space – limiting the appeal of large-scale plant growth systems in terms of Equivalent System Mass (ESM) when considering long duration mission architectures. Plants grown hydroponically or aeroponically represent a logistically favorable alternative for space-based plant growth systems, as nutrients are delivered without the added mass of a soil-like media. However, by removing the media material, controlling the water delivery and recovery in a microgravity environment presents a challenge. Astro Garden is being developed to provide a large-scale space-based aeroponic plant growth system, leveraging modifications of current designs meant to operate within a gravitational environment. This paper examines: the challenges surrounding aeroponics/hydroponics in microgravity, what techniques have been attempted thus far, to what varying degrees of success, and how they can be adapted to the Astro Garden design for future flight systems.