Capillary Movement of Liquid in Granular Beds in Microgravity

A more complete understanding of the dynamics of capillary flow through an unsaturated porous medium would be useful for a number of space and terrestrial applications. One such application involves the development of an effective water and nutrient delivery system for the growth of plants in space. An experiment was conducted on the Mir Space Station that used an experimental cuvette called “Capillary Test Bed”. An objective of this experiment was to compare fluid migration in the “Capillary Test Bed” under terrestrial laboratory simulated microgravity conditions by positioning the cuvette such that the hydrostatic force is negated and on Mir at microgravity conditions. Differences in fluid migration in the cuvette were observed. Based on these observations, improvements in the design of the cuvette are underway, and should allow for collection of more precise data in future flight experiments. The results of the Mir experiment as well as the modifications to the cuvette for improved data collection will be discussed further in subsequent sections.