Study of film structure minimizing destruction by hyper-velocity impact

未来的大型空间结构，如太阳能卫星（SPS），考虑到运输成本，将采用薄膜结构。对于在轨的大型结构物，空间碎片和微流星体的超高速撞击是不可避免的。本研究的目的是研究加强薄膜结构，最大限度地减少超高速冲击破坏。采用轨道炮和二级轻气炮进行了冲击实验。结果发现，薄膜上较低或较高强度线的晶格结构有效地使薄膜破坏局部化，防止破裂的传播。结合薄膜破裂的情况，研究了薄膜边缘夹具对薄膜破裂的影响。结果表明，四边固定的膜的破坏比自由边固定的膜严重。由碎片、撞击等离子体和气体组成的撞击喷射器也使用高速相机和等离子体探针阵列进行了研究。对于碰撞等离子体的传播，发现前向等离子体以与弹丸相同的速度传播，而后向等离子体以较低的速度沿膜表面沿着传播。后者的效果是出乎意料的，但对于设计薄膜太阳能电池阵列以防止冲击时的放电是非常重要的。

Large space structures in the future, such as the Solar Power Satellite (SPS), will use the thin-film structure in consideration of transportation cost. For the large structure in orbit, hyper-velocity impact of the space debris and micro-meteoroid cannot be avoided. The objective of this research is to study reinforcement of the thin-film structure that minimizes the hyper-velocity impact destruction. The rail gun and two-stage light gas gun have been used for the impact experiment. It was found that the lattice structure of lower or higher strength line on the film effectively localized the film destruction, preventing propagation of the rupture. Associated with the film rupture, the effect of the fixture at the film edge was studied. It was found that the destruction for the film fixed at all edges was more serious than that with free edges. The impact ejectors consisting of fragments, impact plasma, and gas that destroy the film itself and forward structures were also studied using a high speed camera and an array of plasma probes. For the propagation of the impact plasma, it was found that the forward plasma propagated at the same velocity as the projectile, while the backward plasma propagated along the surface of the film with a lower velocity. The latter effect was unexpected, but is very important to design the thin film solar cell array to prevent the electric discharge at the impact.