Ground validation of dust multi-properties analyzer onboard Tianwen-2

Tianwen-2, the China upcoming planetary exploration mission, will conduct close-range investigations of the active asteroid 311P/PANSTARRS and execute a sample-return operation from the Earth quasi-satellite 2016 HO 3 , with the aim of advancing our understanding of small-body dynamics and early Solar System evolution. The Dust Multi-properties Analyzer (DMA) onboard Tianwen-2 will investigate the physical properties of particles ejected by 311P. To achieve these scientific goals, a thorough ground validation was performed to evaluate the DMA’s detection capability and measurement accuracy. By virtue of the known characteristics of 311P, 226 mineral particles of four compositional types were selected to serve as analogs of 311P’s dust. Feasible verification methods and third-party validation tools were employed to conduct an experiment on these micron-scale dust particles. The physical quantities of the particles measured by the DMA, such as particle size, velocity, mass and morphology, were verified in the experiment, and the possible deviations in the results were analyzed. This study provides valuable ground-based data support for future in-orbit dust detection, data retrieval and application during the Tianwen-2 mission.