AI 中文总结
研究针对极低地球轨道航天器原子氧风险评估问题，通过耦合多种模型开发几何分辨评估方法，对特定轨道和航天器部件模拟，得出不同轨道通量差异、部件风险排序及多种因素影响，表明需综合考虑多因素评估原子氧耐久性。
AI 中文摘要
原子氧（AO）是极低地球轨道（VLEO）航天器耐久性的主要问题，但轨道平均通量无法解析单个表面和内部部件的暴露情况。本研究通过耦合NRLMSISE - 00、HWM07和SYSTEMA ATOMOX开发了一种几何分辨AO评估方法。对350公里圆形太阳同步轨道在LTAN 06:00和12:00进行了一年模拟，使用基线航天器、楔形修改体和两个合成孔径雷达天线子阵列。LTAN 12:00轨道的轨道平均AO通量比LTAN 06:00高8 - 10%。对于基线几何形状，迎头表面积累了6.9 - 7.5 x 10^21原子/平方厘米，而侧面和天顶/ nadir表面仅接收迎头通量的3 - 5%。材料特定的侵蚀产率改变了部件级风险排名。楔形通过局部屏蔽产生了大约一个数量级的空间变化。外壳开口也使AO能够到达内部印刷电路板。HWM07风产生了10 - 20%的侧板不对称性，禁用风时降至1%以下。与MISSE - 8的比较再现了约4%的测量天顶与迎头比率，但低估了尾流暴露。这些结果表明，VLEO AO耐久性需要综合考虑轨道、大气风、几何形状和材料响应。
英文摘要
Atomic oxygen (AO) is a major durability concern for spacecraft in very low Earth orbit (VLEO), yet orbit-averaged fluence does not resolve exposure on individual surfaces and internal components. This study develops a geometry-resolved AO assessment by coupling NRLMSISE-00, HWM07, and SYSTEMA ATOMOX. One-year simulations were performed for a 350 km circular Sun-synchronous orbit at LTAN 06:00 and 12:00 using a baseline spacecraft, a wedge-modified body, and two synthetic aperture radar antenna sub-arrays. The LTAN 12:00 orbit produced 8-10% higher orbit-averaged AO flux than LTAN 06:00. For the baseline geometry, the ram-facing surface accumulated 6.9-7.5 x 10^21 atoms/cm^2, whereas side and zenith/nadir surfaces received only 3-5% of the ram fluence. Material-specific erosion yields changed the component-level risk ranking: the CFRP zenith panel was predicted to erode by 15.1-16.2 um/year despite receiving much lower fluence than the ram-facing multilayer insulation. The wedge generated approximately one order of magnitude spatial variation through local shielding. Housing openings also allowed AO to reach internal printed circuit boards, with maximum annual fluences of 9.5 x 10^16 and 4.0 x 10^19 atoms/cm^2 in the H- and V-polarized antenna models, respectively. HWM07 winds produced 10-20% side-panel asymmetry, which decreased below 1% when winds were disabled. Comparison with MISSE-8 reproduced the measured zenith-to-ram ratio of approximately 4% but underpredicted wake exposure, identifying a limitation of ballistic ray tracing. These results demonstrate that VLEO AO durability requires coupled consideration of orbit, atmospheric winds, geometry, and material response.
