Capillary-driven Root Module Design for Microgravity

A capillary-driven root module design for growing plants in microgravity is presented. Matrix-based root modules have been developed for conditions of microgravity which require active pumping or an elaborate control system to operate. The capillary-driven system is passive and relies on root uptake to develop the necessary gradient within the media to operate the liquid control valve. A collapsible reservoir supplies water to a porous membrane which maintains the system continuity. Porous membranes facilitate matric potential control and should be matched to the media and operating system limits. Membrane pore size is a key element of the capacity of the system suction. The media particle size should match the system operating limits to maintain adequate air-filled porosity and fluid conductivity.