Autonomous plant watering aboard spacecraft poses persistent challenges for fluid systems designers. However, recent advances in low-g capillary fluidics research are re-invigorating the path forward, making possible the practicable design, fabrication, testing, and demonstration of advanced watering systems for spacecraft plant growth facilities, research platforms, and habitats. Such solutions exploit surface tension, wetting, and system geometry to passively control fluids for reliable separation, collection, and transport. Because such aqueous streams for plant habitats can be highly contaminated with particulates, biofilms, and gases, passive no-moving-parts solutions are attractive due to their simplicity, resilience to fouling, and increased reliability. In this Phase I research effort we propose to develop a scalable autonomous semi-passive omni-gravity hydroponic plant watering system for space applications. The system exploits recent advances in capillary fluidic phenomena demonstrated aboard the ISS to passively and autonomously deliver aerated nutrient-rich water at appropriate plant uptake rates during the various stages of plant growth and development—from germination to maturity. The system is designed for all gravity levels; namely, terrestrial, Lunar, Martian, and microgravity, the latter with NASA’s Deep Space Gateway missions in mind. A low-cost fast-to-flight technology demonstration aboard ISS is proposed as part of our broader Phase II effort.
The system is designed for all gravity levels and may be utilized in current plant facilities aboard ISS or in future missions including Deep Space Gateway, Lunar, or Mars.
We expect the resulting products to appeal to commercial space operators and certain terrestrial markets. Potential products include hydroponic channels, passive stable aerators, passive bubble phase separators, passive flow level controllers, and novel non-occluding conduits, fittings, and valves.