专家：神二十返回舱玻璃裂纹为不足1毫米空间碎片撞击导致

Core Viewpoint - The increasing number of space debris poses a significant threat to the safety of operational spacecraft, satellites, and astronauts, necessitating urgent attention and measures to mitigate risks [3]. Group 1: Space Debris Threat - The quantity of space debris has surged in recent years, leading to heightened risks for in-orbit operations [3]. - A recent incident involving the Shenzhou 20 mission was halted due to a crack found on the spacecraft's window, which was preliminarily assessed to be caused by space debris [3]. Group 2: Incident Details - The crack was estimated to be caused by debris smaller than 1 millimeter, but due to its high velocity, it resulted in a significant crack measuring several millimeters [3]. - The full extent of the damage will be assessed once the Shenzhou 20 spacecraft returns for a detailed inspection [3].