Study on Protection of Space Structure from Micrometeoroid Impact

为实现微流星体对空间站等空间结构的超高速撞击仿真，搭建了等离子体加速器，并进行了撞击速度为10 km/s的实验。有效的保护结构是双元件屏蔽结构。要求随着冲击速度的增大，保险杠板的厚度和主壁与保险杠之间的间隙增大。采用高、低冲击阻抗材料组成的双层保险杠板，对其减重和减小保护结构间隙进行了试验。采用0.5 mm玻璃珠作为微流星体模型。这种大小的珠子被加速到13.8千米/秒。这个值是世界纪录。对2024Al合金和铜双层保险杠板进行了试验。结果表明，在碰撞速度大于10 km/s的情况下，前铝合金后铜保险杠的防护能力非常好。由于铜的密度很高，所以不适合作为空间站的结构材料。陶瓷被认为是一种轻密度和高冲击阻抗的材料。由铝合金和氧化铝组成的新型保险杠将在下一阶段的研究中进行测试。

For the hypervelocity impact simulation of micrometeoroids on the space station and other space structures, a plasma accelerator was constructed and tested over the impact velocity of 10 km/s.The effective protection structure is the dual element shield structure. It is required to increase of thickness of the bumper plate and gap between main wall and bumper with increasing impact velocity. A double layer bumper plate consisted of high and low shock impedance materials were tested for reducing weight and gap distance of the protection structure. 0.5 mm glass beads were used as a model of micrometeoroids. This size of beads has been accelerated up to 13.8 km/s.This value is the world record. The double layered bumper plates consisted of 2024Al alloy and copper were tested. It was found thated protection ability of the bumper consisted of front aluminum alloy and rear-copper is very high in the case higher than 10 km/s impact velocity.Since copper density is high, usage of this material as space station structure is not suitable.Ceramics have been considered as light density and high shock impedance materials. The new type bumper consisted of aluminum alloy and aluminum oxide will be tested on the next phase study.