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More Starlink satellites are falling, and it's because of the sun: Here's how
Double trouble!
and his billion-dollar space company
have both been facing a difficult time recently. While the former is a victim of his own actions, his company is being attacked by the king of the solar system – the sun.
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According to a recent study by a NASA research center, cited by media reports, the Sun's intensifying activity is affecting Earth's satellites, particularly those in SpaceX's Starlink constellation.
As the Sun approaches the peak of its 11-year cycle, there is a surge in geomagnetic storms which is causing more and more Starlink satellites to deorbit and fall from the sky.
On Monday, an expert warned that while the Starlink satellites typically burn-up during atmospheric re-entry, their de-orbiting phase presents significant risks, as their unpredictable trajectories can create collision hazards for other spacecraft present in Low Earth Orbit (LEO).
After their launch in 2019, SpaceX satellites began their atmospheric re-entry in 2020 when two satellites fell from the sky. However, in the progressive years, more and more such satellites have fallen.
In 2021, 78 satellites fell, in 2022, 99 satellites fell; and in 2023, 88 fell. The figure surged even higher in 2024 when 316 Starlink satellites fell out of the sky, as per a report by a team led by space physicist Denny Oliviera of the NASA Goddard Space Flight Center, reported Science Alert.
It was when the researchers analysed the 523 Starlink satellites that entered the Earth's atmosphere again between 2020 and 2024, that they figured out the clear correlation with solar behaviour. This was the period when the Sun escalated towards the peak of its activity cycle.
"We clearly show that the intense solar activity of the current solar cycle has already had significant impacts on Starlink reentries," wrote the researchers.
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"This is a very exciting time in satellite orbital drag research, as the number of satellites in low-Earth orbit and the level of solar activity are at historic highs."
What is the 11 year cycle?
Image credits: Getty Images
The solar cycle is an 11-year cycle of fluctuations in the Sun's activity, and currently it is at the peak of this cycle. This means a rise in solar activity and thus solar ejections, which has left the upper atmosphere heating up significantly. The added heat energy causes the atmosphere to expand, increasing the drag on spacecraft in low Earth orbit and making it difficult for them to maintain their trajectories.
"This phenomenon is normal and is caused by atmospheric anomalies due to heightened solar activity. When solar activity intensifies, the upper boundary rises, increasing collisions between low-orbit satellites and atmospheric molecules, which accelerates orbital decay. The satellites gradually lose speed and eventually deorbit," Wang Ya'nan, chief editor of Beijing-based Aerospace Knowledge magazine, told the Global Times on Monday.
Typically, high-value satellites have autonomous orbit adjustment capabilities that allow them to handle the impact of the solar activities. However, the Starlink satellites that have been designed as low-cost, high-density, mass-produced satellites have a weaker orbit control.
According to Wang, Starlink satellites burn up quickly and thus are unlikely to become long-term space debris or hit Earth's surface. They just pose an ability to affect other low-orbit space launches.
