How quickly could satellites start crashing into each other if they suddenly lost their ability to dodge collisions? A recent study reveals a shocking answer: within just three days. This could set off a dangerous series of crashes that might render space around Earth unusable.
The research, currently in preprint at arXiv, has yet to undergo peer review. Still, it raises important questions about how we use space. The authors introduce the concept of the “Crash Clock.” This clock estimates how soon a collision might happen by modeling all known space objects and calculating collision rates in various orbital zones without any avoidance moves.
In the crowded low Earth orbit (LEO) region, where many satellite constellations like SpaceX’s Starlink operate, a collision could occur in as little as 2.8 days. To compare, researchers also looked at data from 2018, when the first collision would have taken about 128 days. Samantha Lawler, an astronomy professor at the University of Regina, highlighted the drastic changes since then.
This isn’t just theoretical. Solar storms, like coronal mass ejections (CMEs), can disrupt satellite trajectories. A notable example occurred during the 2003 Halloween storm, which caused satellite operators to lose track of their crafts for days. Back then, only a few hundred satellites were active, and no collisions happened. But if a storm as powerful as the Carrington Event of 1859 hit today, the results could be disastrous.
Sarah Thiele, an astrophysics researcher at Princeton, explained how a solar storm significantly increases atmospheric drag on satellites, making it hard to predict their paths. She mentioned that uncertainties can stretch several kilometers, complicating collision predictions.
Status quo concerns arise as the number of operational satellites continues to balloon. We currently have around 13,000 satellites and over 43,500 pieces of large debris tracked by the European Space Agency. These objects zip around Earth at dizzying speeds, making the risk of collision alarmingly high. Starlink alone performed 145,000 avoidance maneuvers in just six months before July 2025.
Industry analysts anticipate that tens of thousands more satellites could be launched by 2035, exacerbating the issue. Lawler and Thiele refrained from speculating how much shorter the Crash Clock could get with this potential increase.
To mitigate risks, satellite operators can de-orbit old satellites and be strategic about where they launch new ones. Lawler noted that controlling satellite density is crucial for managing future risks. Thiele emphasized the fragility of our current space environment, which requires error-free operations to prevent catastrophe.
Experts warn that a large solar storm is inevitable. With over 300 global space launches in 2025 alone, the question remains: will satellite operators be prepared? The space race is only getting more competitive, increasing the chances for potential collisions.
For more insights on the current state of space debris and potential solutions, you can check out this European Space Agency report.
