Scientists warn that low Earth orbit is becoming increasingly crowded, with thousands of satellites relying on constant, error-free maneuvering to avoid collisions, reports Margo Anderson of IEEE Spectrum. To illustrate this growing risk, researchers developed the “CRASH Clock,” a metric that estimates how quickly a collision would occur if satellites suddenly lost the ability to maneuver—currently calculated at just 5.5 days.

While this does not signal an imminent Kessler syndrome cascade, it highlights the increasingly narrow margin for error in orbit, especially amid rising debris, dense megaconstellations like Starlink, and disruptions from solar storms. The findings underscore the mounting operational, economic, and environmental pressures on Earth’s orbital environment. Anderson writes:

Thousands of satellites are tightly packed into low Earth orbit, and the overcrowding is only growing.

Scientists have created a simple warning system called the CRASH Clock that answers a basic question: If satellites suddenly couldn’t steer around one another, how much time would elapse before there was a crash in orbit? Their current answer: 5.5 days.

The CRASH Clock metric was introduced in a paper originally published on the Arxiv physics preprint server in December and is currently under consideration for publication. The team’s research measures how quickly a catastrophic collision could occur if satellite operators lost the ability to maneuver—whether due to a solar storm, a software failure, or some other catastrophic failure. […]

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