New research suggests that increased solar activity is shortening the lifespan of SpaceX’s Starlink satellites and may cause them to return to Earth at a faster rate. Perhaps intuitively, this could increase the risk of satellite debris falling to Earth.
This preprint of the study, which has yet to be peer-reviewed, adds to the growing body of evidence that solar storms are damaging Elon Musk’s Starlink satellites. Over the past few years, the frequency and intensity of these storms has increased as the Sun approaches solar maximum, the peak of its 11-year cycle. At the same time, the number of satellites orbiting the Earth has skyrocketed, thanks in large part to the emergence of private mega constellations such as Starlink.
A team of researchers led by Danny Oliveira of NASA’s Goddard Space Flight Center tracked the reentry of Starlink satellites between 2020 and 2024. This period coincided with the ascending phase of the current solar cycle, when solar activity is increasing ahead of the solar maximum that occurred in October 2024.
Over these five years, 523 Starlink satellites have returned to Earth’s atmosphere. Oliveira and his colleagues analyzed the orbits of these satellites using a statistical method that reveals patterns in the rate at which they de-orbited and re-entered the atmosphere during periods of high solar activity.
The researchers found that geomagnetic activity – disturbances in the upper atmosphere caused by solar eruptions – causes Starlinks to enter the Earth’s atmosphere earlier than expected. These satellites are designed to stay in orbit for about five years. But during strong geomagnetic storms, their lifespan can be reduced by 10-12 days, Oliveira told Gizmodo.
He and his colleagues believe this is because geomagnetic activity heats up the atmosphere and causes it to expand. This increases the drag on satellites, shortening their lifespan and causing them to lose altitude faster as they interact with the upper atmosphere. Furthermore, atmospheric drag can increase the likelihood of satellite collisions, as the orbital models used to develop collision avoidance measures do not fully account for the impact of geomagnetic activity. The results of the study are now available on the arXiv preprint server.
A difference of 10-12 days may seem insignificant, but it could make it nearly impossible for SpaceX to ensure that Starlink satellites return to Earth through a controlled reentry, Oliveira explained. Moreover, his analysis shows that the increased drag forces the satellites to enter the atmosphere at a higher rate, which he believes could increase the likelihood of debris falling to the ground.
This may seem counterintuitive, as increasing the speed of an object during re-entry tends to increase the likelihood of complete disintegration. But Oliveira suggests that stars falling at higher speeds may have a better chance of surviving reentry due to less interaction with the atmosphere. Further research should confirm this hypothesis, as the study did not directly assess the risks associated with debris.
Starships are designed to burn up completely upon reentry, but this does not always happen. In 2024, a 5.5-pound (2.5 kilogram) piece of Starlink debris crashed onto a farm in Saskatchewan, New Scientist reports. In February of this year, SpaceX said that fragments of Starlink debris could fall back to Earth, but claimed that this posed “no risk to people on the ground, at sea, or in the air.”
According to Harvard University astronomer Jonathan McDowell, who tracks the constellation, there are more than 7,500 Starlinks in orbit. Eventually, SpaceX hopes to increase this fleet fivefold, with a goal of launching 42,000 Starlinks in total, Space.com reports. This is in addition to the thousands of other satellites currently orbiting the Earth.
