Overview: A growing hazard from old satellites
An unusual visual spectacle over Calgary recently captured headlines and highlighted a broader concern: dead satellites turning into space junk. The debris problem has moved from a theoretical worry to a practical challenge that could affect communications, weather forecasting, and even human spaceflight. As more objects populate orbit, the risk of collisions grows, complicating a busy orbital environment that billions rely on every day.
How dead satellites become space junk
Satellites reach the end of their operational life in various ways. Some are intentionally deorbited to burn up in the atmosphere; others are left to drift, or become inoperable when fuel runs dry or batteries fail. When these systems break apart—through vented fuel, battery explosions, or small collisions—their fragments scatter into thousands of smaller pieces. Each fragment can travel along its own orbital path, posing a threat to other satellites, ground infrastructure, and crewed missions.
The danger of fragmentation
Even tiny shards, centimeters in size, can injure or disable a functioning satellite. Larger pieces, if they collide with a satellite or the International Space Station, can create a cascade of debris that multiplies the risk for decades to come. This is the essence of the Kessler syndrome: a self-perpetuating chain reaction of collisions that makes certain orbits unusable.
Why scientists are worried
Space agencies and researchers fear a future where the orbital environment becomes so cluttered that routine operations require constant avoidance maneuvers, reducing the effective lifetime of satellites and increasing launch costs. A crowded low-Earth orbit complicates weather forecasting, navigation, disaster response, and national security missions. For scientists and engineers, it also means more uncertainty in mission planning, shorter replacement cycles, and higher insurance costs for operators.
What’s being done to address the problem
There are practical steps to curb debris: design satellites with end-of-life disposal in mind (passivation, batteries drained, fuel vented, and controlled deorbit at mission end); adhere to international guidelines like the 25-year rule for deorbiting from low-Earth orbit; and pursue active debris removal research to physically clear junk from space.
Industry and governments are also improving space traffic management: tracking more objects, sharing orbital data, and coordinating collision avoidance maneuvers. The surge of mega-constellations has intensified these efforts, pushing researchers to develop robust models of debris generation and robust policy frameworks to prevent future cascades. Some missions aim to test debris-removal technologies, offering a path to cleaning up orbit in the coming decades.
A look ahead
Scientists emphasize prevention and cleanup in tandem. Reducing the creation of new junk means better design, stricter end-of-life protocols, and tighter international cooperation. In the meantime, observers of the night sky—like those who noticed the Calgary spectacle—are reminded that space is a shared, finite resource. The choices made today about how we deploy and retire satellites will shape a safer orbital environment for generations of explorers and customers who rely on space-based services.
