Collecting millimeter-level particles automatically and efficiently by electrostatic sampler

The exploration of asteroids is important for explaining cosmogenic origins. Sampling on asteroids has attracted extensive attention from researchers but remains full of challenges. Here, a novel electrostatic sampler (ES) for extracting samples in asteroid environments is proposed. The ES consists of a sampling head and a DC high-voltage generator. Furthermore, its working principle, structure design, and key-parameter design were devised to ensure a high sampling ability. The sampling experiments were conducted using simulant lunar regolith, quartz sand, glass sand, iodized salt, non-iodized salt, iron powder, and expanded polystyrene particles in Earth environment. The results demonstrated that particles with high charge-to-mass ratios and high conductivities can be sampled at high efficiencies. For example, simulant lunar regolith with sizes ranging from 140 mesh to 150 mesh and conductivity of 4.99e−6 S/m can be sampled at a rate of 26.54 g in 30 s using an applied voltage of 12 kV. On the other hand, particles with low charge-to-mass ratios and low conductivities cannot be sampled or can only be sampled at extremely low efficiencies. The experiment results proved that the ES is a high-efficiency, low-energy method for sampling particles. This method opens a new avenue for future asteroid sample-return missions.