In 1983, a single speck of paint floating in space hit the window of the space shuttle. Challengerleaving a 0.25 inch (0.6 cm) indentation in the glass. This incident, although apparently minor, revealed the magnitude of the dangers posed by the space junkobjects traveling at speeds of more than 25,000 km/h (15,600 mph). Four decades later, the situation is even more alarming: millions of fragments of inactive satellites and rockets fill Earth’s orbittransforming it into a debris field that threatens not only space missions, but also essential services that depend on satellites.
On June 27, 2024, astronauts aboard the International Space Station (ISS) They had to take refuge in an emergency capsule when the remains of a destroyed Russian satellite passed dangerously close to their path. Although the team was able to resume activities within an hour, the event highlighted the growing danger of orbital congestion. Incidents like this are not isolated. Since the beginning of the space age in 1957, there have been more than 650 fragmentations, explosions and collisions that have left a trail of debris that is almost impossible to manage.
Beyond the immediate risks for space crews, the proliferation of space debris directly affects satellites that support crucial technologies such as GPS navigation, television broadcasting and the Internet, and climate monitoring systems. According to experts, the situation is reaching a critical point that could lead us to a scenario known as the “Kessler syndrome”a phenomenon in which an initial collision generates a chain reaction that renders much of the Earth’s orbit useless.
Space debris, or orbital debrisincludes any artificial object that is no longer useful but remains in orbit. This ranges from broken satellites to rocket parts, fragments resulting from collisions, and even tiny paint chips. Despite their diversity, they all have something in common: they travel at extreme speeds, becoming lethal projectiles for any object in their path.
The magnitude of the problem is overwhelming. The European Space Agency (ESA) It is estimated that there are at least 29,000 fragments larger than 10 cm, 670,000 between 1 and 10 cm, and more than 170 million smaller than 1 cm. Although small fragments cannot be precisely tracked, even a millimeter-sized object can puncture critical parts of a spacecraft or satellite, putting human lives and essential technologies at risk.
In orbit, these objects are so dispersed that most do not collide, but the exponential increase in launches in the last decade has intensified the problem. According to Professor Vishnu Reddy of the University of Arizona, “the number of objects in space that we have launched in the last four years has grown exponentially.”
The term “Kessler syndrome” was coined in 1978 by astrophysicist Donald Kessler, who imagined a scenario in which collisions of objects in orbit would produce more fragments, generating a cascade effect. If this were to occur, the resulting debris could render large areas of low-Earth orbit useless, complicating space launches and damaging critical satellites.
Although experts debate whether this syndrome is already underway, the evidence suggests that we are getting dangerously close to this scenario. An alarming example was the crash between the American satellite Iridium 33 and the Russian satellite Kosmos 2251 in 2009, which generated more than 2,300 traceable fragments according to a report by CNN. These events not only multiply existing space debris, but also make future missions difficult to manage.
The greatest risks are concentrated in the low earth orbit (LEO)where most satellites and space stations operate. Although fragments in this area tend to deorbit naturally in about 25 years, at higher altitudes objects can remain active for centuries, further complicating orbital cleanup.
Faced with this growing threat, governments and companies have begun to explore both technological and regulatory solutions. The European Space Agency (ESA) explained in a statement that it is testing technologies such as braking sails, which increase atmospheric resistance to accelerate the disintegration of disused satellites. In 2022, such a prototype called ADEO was successfully deployed, demonstrating the potential of these innovations.
However, the costs are exorbitant and it is not yet clear who will assume financial responsibility for these operations. On the other hand, in the regulatory field, the United Nations has promoted agreements such as the Pact for the Future, which seeks to promote discussions on space traffic and debris. However, the lack of compliance mechanisms limits the effectiveness of these initiatives.
Professor Nilton Renno, from the University of Michigan, highlighted in a conversation with LiveScience a disturbing analogy: “Space junk is like plastic in the oceans. “We think space is infinite, but we are causing enormous damage if we don’t act carefully.”
While space agencies work to manage this problem, the reality is that the proliferation of orbital debris continues to outperform mitigation efforts. Without concrete action, we could face a future where access to space is limited or, worse, impossible.
The challenge of space debris is not only technical, but also political and economic. Who should pay for the cleaning? What regulations need to be implemented? These questions require clear answers before Earth’s orbit becomes a graveyard of inoperable technologies, compromising the future of space exploration and our dependence on satellites on Earth.
