A Legged Device Based on Active Buffering for Probe Landing on Microgravitational Asteroid * The landing of the probe on the asteroid surface provides the technical basis for insitu exploration and sampling return and promotes to maximize the value of the probe. The microgravitation and the uncertainty in topography and geology on the asteroid surface pose challenges to the landing of the probe. To develop the asteroid landing technology, the legged landing device of asteroid probe based on active buffering mode is studied in this paper. The landing device adopts a threelegged structure to possess higher adaptability to the surface topography of asteroids and get the light and simple configuration. Besides, a buffering unit is designed based on the active mode of the damping motor which has obvious advantages in selfadaptability and autonomy. Through the comparison of various schemes, the sliderlegged landing device is determined and designed in detail. On this basis, the cosimulation of the probe landing on the asteroid surface is completed, which shows the satisfaction of this device to reliability and efficiency. Finally, a prototype of the landing device is constructed and the microgravitational simulated test platform is developed to implement the landing buffering test of asteroid probe. The test results validate the performance of the landing device.

A Sweeping and Grinding Methods Combined Hybrid Sampler for Asteroid Exploration Successful sampling on the surface of asteroids is difficult because of their weightless environment and unknown material mechanical property. This work presents an asteroid sampler based on sweeping and grinding methods to improve the success rate of sampling. The sampler uses two brushes rotating clockwise and counterclockwise to collect sample particles on the surface of asteroids. When encountering the hard rock or sample particles with large cohesion, the sampler adopts a drill bit to grind them to loose samples suitable for collecting by the brushes. The interaction between the brushes and the regolith is modeled and the sweeping mechanism is designed. A simple grinding mechanism is also designed. Numerical simulation and prototype experiments, at different parameters including blades number, rotational speed, and feeding speed of the brushes, mechanical property of the sample, and gravity, were conducted for validating the proposed methods. The 280g sampler prototype with 8 blades of brushes could collect about 19g regolith simulant in 25s in earth environment. The drill bits could work together with the brushes to improve the sampling efficiency through DEM simulation in case of large cohesion among sample particles. The sampler will be a good choice for installing into an asteroid rover in exploration.