In 1978, NASA researcher Donald Kessler and his colleagues published a paper titled “Collision frequency of artificial satellites: The creation of a debris belt.”
The paper laid down a grim warning: a single collision between satellites that would escalate into a series of followup accidents, “each of which would increase the probability of further collisions, leading to the growth of a belt of debris around the Earth.”
“Under certain conditions, the belt could begin to form within this century and could be a significant problem during the next century,” the prescient paper warned.
Such a catastrophic series of cascading events, has since been dubbed “Kessler syndrome.” The term highlights the considerable risks of littering our planet’s orbit with many thousands of human-made objects, including multiple megaconstellations of satellites, as well as all the junk that gets left behind after they’re launched and decommissioned.
Not only does it put astronauts at risk, but Kessler syndrome could also greatly complicate future space exploration efforts by turning the planet’s orbit into a whirling vortex of death.
Now, an international team of researchers from Princeton University, the University of British Columbia, and the University of Regina, has attempted to quantify this risk by coming up with a new metric, called the “Collision Realization and Significant Harm (CRASH) Clock.”
“There is substantial potential for current or planned actions in orbit to cause serious degradation of the orbital environment or lead to catastrophic outcomes, highlighting the urgent need to find better ways to quantify stress on the orbital environment,” they wrote in a yet-to-be-peer-reviewed paper, first spotted by Gizmodo. “Here we propose a new metric, the CRASH Clock, that measures such stress in terms of the time it takes for a catastrophic collision to occur if there are no collision avoidance maneuvers or there is a severe loss in situational awareness.”
In the case of an extremely powerful solar storm shutting down satellite communications, or a different kind of “widespread disruptive event,” the researchers warn that it could take a mere 2.8 days for a collision to take place.
Put differently, if satellites were to suddenly lose their ability to track and avoid other objects in orbit, it would take less than three days for a potentially catastrophic crash to occur.
Such an event may sound implausible, but the researchers pointed out that countless satellites had to adjust their orbits following a strong solar storm in May 2024. The ensuing chaotic movements made “collision avoidance maneuvers extremely uncertain.”
... continue reading