The unsaturated hydraulic properties of porous media may be altered by a reduction in gravitational force (e.g., microgravity). Long duration space flight experiments are needed for quantifying root-module-scale porous-medium hydraulic properties for plant growth studies and other applications. The Astroculture-1 space-shuttle flight experiment was used to control water addition and removal in plant growth media, thereby providing measurements of porous medium hydraulic properties. Our objectives were to (1) apply models describing unsaturated water flow and distribution in porous media to simulate and inversely fit hydraulic parameters to the Astroculture-1 data, and (2) identify possible differences in 0g compared to 1g using these and other data from parabolic flight experiments. By individually adjusting the porous tube pressures, the water content in the medium was adjusted and monitored by recording the volume of water recovered. Measurements in 0g on the shuttle were complimented by measurements on the ground at 1g. HYDRUS-2D was used to inversely fit water retention and flow data collected both on Earth and in microgravity. Microgravity conditions were simulated in the program using the horizontal flow option which neglects the gravity term in the Richards equation. Building upon earth based theory and laws of unsaturated transport, effects observed in microgravity were qualitatively and quantitatively described. Macroscopic transport properties in microgravity appeared to be modified based on fitting parameter differences compared to 1g simulations. A partial explanation for this phenomenon was recently observed in parabolic flight experiments revealing modified water retention properties under short-term microgravity. Further studies under sustained reduced gravity are needed to more definitely characterize hydraulic properties in microgavity.