Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 14, 2019
At present, Space debris have a lot of problems in the space industry. They are the crush to spacecrafts and making the restriction of orbit in space. ISO 112227 was enacted in 2012 as a measure against microscopic secondary Space debris called Ejecta among space debris. However, this protocol did not take into account oblique impacts of projectiles, and a draft revision is made for the purpose of implementing oblique impact experiments. In this research, as a verification of the revision proposal, a 1 mm diameter projectile simulating micro debris is collided with a two-stage light gas gun at a speed of 5 km.s-1 using a target of A2024-T3, usually used as a spacecraft material. The impact angles are 0 (vertical impact), 45, 60 and 75 degrees. About the evaluation method, it is based on the generation amount of Ejecta and its distribution throughout impact marks. Since the target is a ductile body, the amount of Ejecta generated is small, and so it is difficult to calculate accurate ejecta mass at 60 and 75 degrees. Since the angle also increases the distribution of impact marks, scavenging of Ejecta is insufficient. In order to solve this problem, the way of collecting Ejecta is reviewed in oblique impact experiments.
