The accumulation of space debris in low Earth orbit (LEO) has reached a dangerous tipping point, according to leading scientists and space agencies. With thousands of objects—from defunct satellites and abandoned rocket stages to fragments from anti-satellite (ASAT) tests—hurtling through space at extreme speeds, experts warn that a catastrophic collision is now inevitable. The growing threat has sparked concerns about the safety of astronauts, satellites, and the increasing number of missions to space.
The Looming Disaster: Space Junk in Low Earth Orbit
Today, LeoLabs, a firm that specializes in tracking orbital objects, monitors more than 30,000 pieces of space debris larger than a softball in low Earth orbit. These objects travel at speeds of up to 28,000 kilometers per hour, making any collision potentially devastating. One of the most dangerous aspects of this debris is that even objects as small as a few millimeters could cause lethal damage to spacecraft or space stations. According to Darren McKnight, Senior Technical Fellow at LeoLabs, the current situation in space can be described as a “ticking time bomb.”
McKnight and his team have raised alarms about the severe risks posed by space junk, particularly from ASAT missile tests and ghost rockets—spent rocket stages abandoned in orbit after past space missions. These remnants are left spinning uncontrollably, waiting to collide with something in their path. In an interview, McKnight warned that “decades of abandoning rockets in orbit, and firing off anti-satellite missiles, are surrounding Earth with ‘time bombs’ that will threaten astronauts into the future.”
Close Calls and Cascading Collisions
Space debris poses a particularly high risk to human spaceflight. Although no human lives have yet been lost to collisions with space junk, the International Space Station (ISS) has already experienced several close calls. In 2021, a small piece of debris punched a 5-millimeter hole in the robotic Canadarm2 attached to the ISS. While the damage was relatively minor, the event underscored the seriousness of the threat. As Dan Ceperley, Chief Operating Officer at LeoLabs, explains: “Any size fragment above a few millimeters is likely lethal to astronauts. What we can’t see has the potential to kill us.”
The real danger comes from a phenomenon known as the Kessler Syndrome, where a single collision in space could generate more debris, leading to further collisions in a cascading effect. If two large objects, such as derelict rocket stages, collide, they could unleash a cloud of debris that would remain in orbit for centuries, posing a constant hazard to space missions.
A near-disaster occurred in June 2022, when two enormous rocket bodies—one from the Soviet era and the other American—came within 500 feet of colliding. Had they collided, the resulting debris field would have spread over hundreds of kilometers, threatening space stations, satellites, and future missions. McKnight emphasized the severity of such an event, saying, “The clash would have been cataclysmic, spewing debris over many hundreds of kilometers and creating shrapnel that would linger for centuries.”
International Cooperation and Diplomatic Hurdles
Despite the growing threat, efforts to address space debris have been slow, especially among the world’s biggest spacefaring nations—Russia, China, and the United States—which are responsible for 90% of the debris in low Earth orbit. These nations have yet to reach a consensus on how to mitigate the debris they’ve left behind, and diplomatic efforts to clean up space have faced numerous challenges.
Ian Christensen, Senior Director at the Secure World Foundation, stresses the need for international cooperation. “The biggest diplomatic challenge is convincing the three major spacefaring countries to begin remediating their own large debris objects,” said Christensen. However, he warns that, without a global commitment, the situation could spiral out of control. Some experts believe that only a major debris-generating collision might galvanize global powers into taking action.
While other countries like Japan, the United Kingdom, and Europe are working on small-scale Active Debris Removal (ADR) projects, large-scale solutions remain in their infancy. In the United States, the proposed ORBITS Act seeks to provide initial funding for ADR technologies, but it has yet to pass Congress.
A Race Against Time: The Future of Space Exploration at Risk
The dangers posed by space debris are not limited to astronauts and space stations; they also threaten the satellites that power global communication, weather monitoring, and navigation systems. With the number of satellites in orbit expected to grow exponentially in the coming years, experts fear that the situation could worsen unless proactive measures are taken.
LeoLabs is using cutting-edge radar and AI technologies to track space debris and predict high-probability collisions, but the organization acknowledges that it can only track objects larger than 10 centimeters. The true danger lies in the countless smaller fragments that go undetected. “This grim reality means that collisions are not a question of if but when,” warned Ceperley.
The risk to commercial satellites and the rising number of mega-constellations, such as SpaceX’s Starlink, adds another layer of complexity. McKnight and his colleagues at LeoLabs have identified 18 abandoned Russian rocket stages as part of the “top 50 objects” that should be prioritized for removal to prevent catastrophic events.
Can We Clean Up Space Before It’s Too Late?
Experts agree that more aggressive action is needed to clean up space debris and prevent further risks to future missions. However, there is no economic incentive for countries or companies to invest in debris removal, making it difficult to mobilize resources for large-scale cleanup efforts. With the global space economy forecast to reach over $1 trillion by 2040, some believe that Active Debris Removal (ADR) missions could eventually become viable and affordable.
Both McKnight and Christensen are advocating for immediate action at forums such as the International Astronautical Congress (IAC), where leading space scholars discuss solutions to the crisis. One proposed idea involves using robotic space tugs to capture large pieces of debris and deorbit them safely. In the long term, some visionaries, such as Jeffrey Manber of Voyager Space, envision recycling abandoned rocket stages to convert them into orbital habitats or space station modules.
As the space industry continues to expand, the race to clean up space is becoming more urgent. Without concerted global efforts, the ever-growing problem of space debris could jeopardize the future of human spaceflight and technological progress.