Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 17, 2020 - December 18, 2020
In the touchdown operation of Hayabusa2, scattering of surface particles by thruster plume impingement flow has observed. There are risks that flying particles effect equipment such as sensors and cameras, so it is necessary to assess the behavior of particles that scattered by thruster injection. In order to clarify the parameters that affect the phenomenon and elucidate the mechanisms, we conducted experiments that inject gas onto soil simulated celestial surface. We used a method of visualizing crater formation using an acrylic transparent plate and capturing the flying particles by irradiating a line laser. In addition, conducted experiments in a microgravity environment using 50 meters drop tower “Cosmo-Torre”. From results, in microgravity environment, the bearing capacity of the soil released, shearing occurred inside the soil, and it scattered as a layered mass. When using different soils, the scattering direction differed depending on the particle size, and the Phobos simulant maintained the bearing capacity of the soil and did not cause large erosion. The outline and results of the experiments conducted are described.
