The variable electromagnetic environment in geospace plays a crucial role in influencing the occurrence probability of satellite anomalies. FORMOSAT-3 (FS3) is a Low-Earth-Orbit (LEO) mission, which consists of six identical microsatellites that orbit in the altitude of 700–800 km and with an inclination of 72°. The dependences of the FS3 satellite anomalies on space weather conditions have not been investigated in the past. With an exception of a small number of extremely high geomagnetic events, we find that the occurrence rate of the FS3 anomalies is negatively correlated with the level of geomagnetic activity. Moreover, the relationship between numbers of anomalies and sunspots is also anti-correlated. A superposed epoch analysis demonstrates that the intensity of galactic cosmic rays (GCR) is relatively high at the times of the anomalies. All these results infer that the FS3 anomalies predominantly occurred under the conditions associated with low solar activity. The possible main cause for the FS3 anomalies is high-energy trapped protons or GCR. In summary, this paper presents a statistical result that a satellite can be prone to suffer an anomaly under low solar or geomagnetic activity.

地球空间中可变的电磁环境在影响卫星异常发生概率方面起着至关重要的作用。FORMOSAT-3（FS3）是一项低地球轨道（LEO）任务，由6个相同的微卫星组成，它们在700-800 km的高度内运行，倾角为72°。过去尚未研究FS3卫星异常对空间天气状况的依赖性。除了少数极高的地磁事件外，我们发现FS3异常的发生率与地磁活动水平呈负相关。此外，异常数量和黑子之间的关系也是反相关的。叠加的历时分析表明，在异常时刻，银河系宇宙射线（GCR）的强度相对较高。所有这些结果表明，FS3异常主要发生在与太阳活动低有关的条件下。FS3异常的可能主要原因是高能陷阱质子或GCR。总而言之，本文提出了一个统计结果，即在太阳或地磁活动低的情况下，卫星容易遭受异常影响。