Assessing Water Dynamics at Lunar Gravity

Because future plant cultivation on the Moon will require lunar-gravity specific water management, we examined the behavior of water, a glycerol and saline solution under lunar gravity conditions during a flight experiment on Blue Origin’s New Shephard 29 mission. This mission simulated lunar gravity as centrifugal force by rotating the capsule during the weightlessness phase. The menisci of the fluids were imaged, compared with ground controls, and modeled using the Young–Laplace equation. Compared with theoretical values, the estimates for surface tension and capillary length for both controls and flight data were lower than literature values but generated values for glycerol that were higher than for water. These data indicate how the effect of surface features overrides fluid behavior and the difficulty of obtaining experimental data under space flight conditions. The results suggest future studies that include water movement and wetting studies in the presence of lunar regolith as crucial factors to prepare for lunar plant cultivation.