In 1978, NASA researcher Donald Kessler issued a stark warning about space debris. His paper, “Collision frequency of artificial satellites: The creation of a debris belt,” predicted that a collision between satellites could set off a chain reaction, leading to a dangerous “debris belt” around Earth. This phenomenon is now known as “Kessler syndrome.”
Kessler syndrome poses serious risks—not just for our astronauts but for future space missions as well. With an increase in man-made objects in orbit, the threat of collisions grows. A recent study from an international team, including researchers from Princeton University, introduced a new warning system called the “Collision Realization and Significant Harm (CRASH) Clock.” This metric estimates how quickly a catastrophic collision could occur without proper avoidance measures.
The team found that if a significant solar storm disrupted satellite operations, a collision could happen in just 2.8 days. This underlines the urgency of developing better tracking and communication technologies in space. In 2018, the risk was much lower, with a CRASH Clock of around 121 days. The satellite landscape has changed dramatically, with the number of objects in low-Earth orbit nearly doubling from 13,700 in 2019 to over 24,000 projected by 2025.
SpaceX leads this charge, having launched over 10,000 Starlink satellites. Currently, about 9,000 of these are functional, accounting for over 60% of active satellites. While these satellites are designed to disintegrate upon reentry, the sheer volume raises collision risks.
Just recently, SpaceX reported a loss of contact with a Starlink satellite, heightening concerns. The satellite is expected to reenter the atmosphere safely, but this incident highlights the precarious nature of our orbit.
Other companies, including Amazon and China’s space agency, are also working on their own satellite networks, likely leading to even more congestion in orbit. Experts warn of potential damage not only from collisions but also from the pollutants released when satellites burn up in the atmosphere.
With all this in mind, there’s a growing chorus for stricter regulations and better monitoring of space activities. Keeping our orbit safe is becoming increasingly critical as we continue to explore beyond our planet.
For more on this topic, you can check out the NASA website on space debris.
