Solar Storms Are Causing Elon Musk's Starlink Satellites To Fall From The Sky

The Sun's growing activity is affecting Earth's satellites, particularly those in the Starlink constellation launched by SpaceX. As the Sun approaches the peak of its 11-year cycle, increased geomagnetic storms are causing more satellites to fall out of orbit and re-enter the atmosphere. Denny Oliveira, a space physicist at NASA's Goddard Space Flight Centre, led a study on 523 Starlink satellites that fell back to Earth between 2020 and 2024. The study revealed that geomagnetic storms caused by the Sun's eruptions increased atmospheric drag, causing satellites to re-enter faster than expected.

"We clearly show that the intense solar activity of the current solar cycle has already had significant impacts on Starlink reentries. This is a very exciting time in satellite orbital drag research, since the number of satellites in low-Earth orbit and solar activity are the highest ever observed in human history," the NASA team wrote in the paper.

As per Science Alert, the solar cycle, an 11-year period of fluctuating solar activity, involves a magnetic reversal of the Sun's poles, marked by sunspots, solar flares, and coronal mass ejections. Activity peaks at solar maximum, when the poles flip, and declines to a minimum before rising again. We're currently at the peak of the 25th cycle, which has been stronger than predicted, though not the strongest recorded.

This heightened activity impacts Earth significantly. Solar particles, carried by coronal mass ejections and solar wind, create vibrant auroras by interacting with the atmosphere. Less visibly, increased solar activity heats the upper atmosphere, causing it to expand. This expansion increases drag on spacecraft in low-Earth orbit, requiring trajectory adjustments to maintain their orbits.

All low-orbit satellites are affected, but SpaceX's Starlink constellation, with 8,873 satellites launched and 7,669 still operational, provides a unique case study for analysing solar maximum on satellite operations. As a result, satellites need to make adjustments to maintain their trajectory, and the increased drag can even cause some to fall out of orbit.

"Here, we use … Starlink orbital data to perform a superposed epoch analysis of orbital altitudes and velocities to identify impacts caused by storms with different intensities. The Starlink reentries coincide with the rising phase of solar cycle 25, a period with increasing solar activity," the researchers wrote. 

Starlink satellites

Notably, SpaceX's Starlink satellites aim to provide global high-speed internet access, especially to remote areas with limited or no connectivity. Each Starlink satellite has a limited lifespan, which is typically less than five years. After this period, the satellites re-enter the atmosphere and burn up before reaching the ground.

However, the growing number of satellites in Earth's orbit poses challenges beyond their benefits. One major concern is the obstruction they cause to astronomical observations, as these satellites can reflect sunlight and interfere with stargazing and scientific research. Further, the increased launches of human-made satellites are contributing to the accumulation of space junk in Earth's orbit.