Ballistic Range Experiment of Spherical Body in Particle-laden Environment

Abstract

Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in particle-laden environment was experimentally simulated by using the ballistic range. In case of high-speed motion, cracking of particles occurs as well as the damage on the projectile surface. To establish the experimental simulation technology and to obtain the fundamental characteristics of such complicated phenomena, a projectile was launched by the ballistic range at the velocity up to 500 m/s and the collective behavior of particles around the body was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 100 – 400 μm diameter were scattered in the test chamber uniformly. The projectile was launched into a particle sheet in the tangential direction. The high-speed camera captured both the projectile and particle motion. From the movie, the interaction between the projectile and particle sheet was clarified. The damage on the surface of the projectile recovered after the shot was also observed.