Low Earth orbit has become a crowded neighborhood. Once home to a handful of satellites and orbital research stations, it’s now filled with tens of thousands of objects—many no longer serving any purpose. From working satellites to broken pieces of metal, dead rocket stages, and microscopic paint flecks, space debris hurtles around Earth at 17,000 miles per hour.
At those speeds, even a small fragment can punch through metal like a bullet. Space agencies warn that this buildup could trigger what’s known as the Kessler syndrome—a scenario where one collision causes a cascade of others, filling orbit with so much debris that it becomes unsafe for future missions. It’s a slow-motion crisis that has been decades in the making, and one that now demands urgent action.
NASA scientist Donald Kessler first described the danger back in 1978, predicting that beyond a certain density, debris in orbit would begin colliding faster than it could decay or burn up. Each new collision would create more fragments, increasing the likelihood of further impacts. That prediction was once considered theoretical. It isn’t anymore. In 2007, China destroyed one of its own satellites during a weapons test, creating over 3,000 trackable debris pieces. Two years later, a dead Russian satellite smashed into an active communications satellite owned by Iridium, producing thousands more fragments. Since then, explosions, breakups, and accidents have steadily added to the problem. As of this year, more than 22,000 large objects are being tracked by radar and optical telescopes, but experts estimate that over a million fragments too small to track—some as tiny as a screw—still pose potentially catastrophic risks to spacecraft and astronauts alike.
The problem isn’t slowing down, and the Kessler syndrome is inching closer to reality. The boom in commercial space activity, especially from satellite constellations designed for global broadband, has intensified congestion in low Earth orbit. SpaceX’s Starlink constellation alone has launched over 6,000 satellites, with plans to expand to more than 12,000 by 2027 and possibly 42,000 in later phases. Amazon’s Project Kuiper, which launched its first two test satellites in late 2024, expects to begin full deployment of more than 3,200 satellites by 2026. OneWeb already operates more than 630 satellites in polar orbit, and China’s Guowang constellation aims to add another 13,000 satellites by the end of the decade. While these networks promise global internet coverage and new commercial opportunities, they also mean thousands of additional objects moving through already congested orbital lanes. Even though most of these satellites are designed to deorbit at the end of their lives, many fail or lose contact before that happens. Once control is lost, so is the ability to steer them out of harm’s way.
Recognizing the risk, space agencies and private companies are now shifting their focus to active debris removal—the process of retrieving, capturing, or deorbiting large, dead satellites and rocket bodies before they can break apart. The European Space Agency (ESA) has taken the lead with a landmark mission called ClearSpace-1, being built by the Swiss startup ClearSpace SA. Scheduled for launch in 2026 aboard an Arianespace Vega-C rocket, the mission will use four robotic arms to capture a defunct 100-kilogram rocket adapter left over from a 2013 launch. Once secured, the spacecraft and debris will reenter Earth’s atmosphere together and burn up safely. It will be the world’s first fully funded debris removal mission.
In the United States, NASA has entered agreements with several companies to develop commercial debris-removal technologies through its Commercial LEO Destinations and Services initiative. One of those companies, Astroscale U.S., a subsidiary of the Japan-based Astroscale Holdings, has become a pioneer in end-of-life satellite servicing.
In 2021, its ELSA-d demonstration mission successfully proved magnetic docking technology that could attach to derelict satellites and pull them down. The company is now preparing for ELSA-M, a larger mission funded by the UK Space Agency and the European Space Agency, expected to launch in 2025. ELSA-M will attempt to deorbit multiple dead satellites from a crowded 600-kilometer orbit. Astroscale’s long-term goal is to offer “debris-removal as a service” by the late 2020s, making cleanup a routine commercial operation.
Japan’s JAXA (Japan Aerospace Exploration Agency) is also investing heavily in cleanup technology. It has partnered with Astroscale on the Commercial Removal of Debris Demonstration (CRD2) project, which aims to capture and remove a large Japanese upper-stage rocket body by 2026 or 2027. JAXA previously tested electrodynamic tether technology that could use magnetic drag to slow debris and help it deorbit. In addition, Japanese firm Sky Perfect JSAT is studying the feasibility of laser-based orbital clearing, using high-powered ground lasers to nudge small debris into decaying orbits without physical contact.
In Europe, Airbus Defence and Space has been developing a system called Harpoon-1, designed to impale and reel in dead satellites using a tethered spike. Another concept, from the UK’s Surrey Space Centre, involves launching small “chaser satellites” equipped with nets that can envelop and deorbit tumbling debris. The RemoveDEBRIS mission, launched from the International Space Station in 2018, tested both the net and harpoon designs successfully. The data collected from that experiment is now informing newer commercial designs expected to fly before 2027.
In the United States, the Defense Advanced Research Projects Agency (DARPA) is working with companies such as Northrop Grumman and Momentus on orbital servicing and refueling technologies. While not designed specifically for debris removal, these systems could help extend the life of satellites and reduce the number of new launches. Northrop Grumman’s Mission Extension Vehicle (MEV) program, for example, has already docked with aging communications satellites to provide propulsion and attitude control, a process that could delay the need to replace them and reduce orbital clutter.
Several startups are exploring low-cost approaches to clean up smaller fragments. California-based OrbitGuardians and Neutron Star Systems are developing compact spacecraft equipped with electric propulsion that could sweep through orbital belts and push small debris into decaying paths. Meanwhile, the European company D-Orbit, based in Italy, operates “orbital tugs” that deliver payloads and then help deorbit spent rocket stages.
NASA and the U.S. Space Force are focusing on improving space traffic management through their Space Command and Control (Space C2) program, using advanced radar and AI-driven analytics to track potential collisions and coordinate avoidance maneuvers. These systems already track over 50,000 orbital objects, but smaller fragments remain invisible to radar, leaving operators largely in the dark about the full extent of the threat.
Even as technology advances, cost and cooperation remain the biggest barriers. Each debris removal mission can cost tens of millions of dollars, and few companies are willing to pay for a service that doesn’t yet yield profit. Some policymakers have proposed an international “orbital clean-up fund”, financed by small fees on satellite launches, or “orbital bonds”—refundable deposits that are returned only when operators prove their satellites have safely reentered the atmosphere.
The Federal Communications Commission (FCC) in the United States has already adopted a new “five-year rule,” requiring operators to remove or deorbit defunct satellites within five years of mission completion, down from the old 25-year standard. The European Union and United Kingdom are expected to adopt similar rules by 2026, while Canada and Australia have announced their own draft frameworks. But enforcement remains a challenge: the vast majority of debris in orbit today was launched before these regulations existed.
The situation has become a race against time. Some scientists believe parts of low Earth orbit may already be beyond the threshold where the debris population will continue to grow even if launches stopped today. Others argue that aggressive cleanup—removing just five to ten large pieces of debris per year—could stabilize the environment within a decade. What’s clear is that the longer cleanup is delayed, the higher the cost becomes.
One European scientist summed it up bluntly: “Space is not infinite. It’s a fragile environment, and we’re running out of safe space to use.” If humanity fails to clean up its orbital backyard, the very highways that carry our satellites, our astronauts, and our dreams of exploration could become impassable. The future of spaceflight, and much of modern life that depends on it, may hinge on how quickly the world learns to take out its trash.
