研究揭示“星链”卫星大量坠落与太阳活动加剧有关

Core Insights - The research highlights the significant impact of increased solar activity on the operational lifespan of low Earth orbit (LEO) satellites, particularly those of SpaceX's Starlink, with a notable rise in satellite falls from 2020 to 2024 [1][2] Group 1: Satellite Fall Trends - From 2020 to 2024, a total of 1,190 satellites fell from very low Earth orbit (VLEO), with 583 of these being Starlink satellites [1] - The number of falling Starlink satellites has shown an increasing trend, correlating with heightened solar activity, rising from 2 in 2020 to 316 in 2024 [1][2] Group 2: Solar Activity and Its Effects - Solar activity follows an approximately 11-year cycle, with the period from 2020 to 2024 being characterized by the rising and peak phases of the 25th cycle [2] - Increased solar activity leads to significant geomagnetic disturbances, causing the Earth's thermosphere to warm and expand, which in turn increases atmospheric density and drag on LEO satellites [2] Group 3: Implications for Satellite Design and Monitoring - The design lifespan of LEO satellites like Starlink is typically around 5 years, but increased geomagnetic activity can lead to earlier re-entry into the atmosphere, shortening the descent phase by 10 to 12 days during intense geomagnetic storms [2] - The research emphasizes the need for enhanced monitoring and predictive measures during periods of intense solar and geomagnetic activity to mitigate risks of in-orbit collisions and satellite debris impacting Earth [2]