Dust Detection Using a Laser Altimeter on Board Hayabusa2

Abstract

The moon and asteroids are known to be covered with dust grains. Since dust grains are thought to travel over the surface of these bodies, they are potentially hazardous for spacecraft, and especially for sample-return missions. However, dust grains detached from the surface are not easy to detect. We have provided the light detection and ranging (LIDAR) system on board Hayabusa2 with a new operational mode, the “dust count mode,” in which LIDAR evaluates whether or not each return pulse from 50 continuous observational ranges exceeds a threshold value. Once Hayabusa2 arrives at its target body of Ryugu, we will make observations with various threshold values in order to detect dust distribution.