Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. We performed a granular flow experiment under stable artificial gravity conditions generated by a centrifuge on the International Space Station. We also performed a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verified that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the granular flow results revealed that the mass flow rate quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.