Satellites bring to mind images of shiny, angular objects orbiting Earth at tremendous speed through the boundless emptiness of space. Yet the orbits are no longer empty. Besides traffic, they are teeming with debris from spacecraft breaking up because of age, explosions, or collisions.
Orbital debris has doubled over the past decade. As of 2026, about 1.2 million objects measuring 1–10 cm are in orbit. Traveling at speeds of 7–8 km per second—10 times that of a bullet and 4–5 times that of the fastest planes—these objects can disable or destroy spacecraft. Without debris management, this growing danger to expensive space projects remains unchecked.
Two companies—ClearSpace and Astroscale—have approached the U.K. Space Agency to demonstrate active debris removal (ADR). ClearSpace has conducted two ADR missions for the agency. Last year, Astroscale received a U.S. patent for its 2021 filing for a cleanup system. Both companies are competing for a contract to remove two defunct British satellites from orbit.
But such nascent efforts are meager. They will not reach meaningful scale unless a binding international legal framework with clear protocols, impartial, well-coordinated monitoring, and enforceable liabilities is established. The current regime is wholly inadequate.
To understand how more than a million man-made fragments came to orbit Earth, consider the number of satellites, the stresses they endure, and the high probability of collisions. Space warfare, a possibility, may add to the problem; but even discounting that, we are creating more debris than we can handle.
Of the four major gravitational orbits, the two most populated are the Low Earth Orbit (LEO), 60–2,000 km above Earth, where satellites complete an orbit in 90–120 minutes; and the Geosynchronous or Geostationary Orbit (GEO), roughly 35,800 km above the Equator, where satellites appear to remain fixed above a point on Earth. In the other two—the Medium Earth Orbit (MEO) and the High Earth Orbit (HEO)—debris is not an urgent problem, but it will become one without checks.
The numbers
The number of spacecraft in LEO has grown exponentially in recent decades. In 2000, there were about 700 satellites in LEO. Today, there are 15,500. SpaceX alone operates more than 10,900. China has over 1,400, and the U.K., Russia, and others have another 1,400. There are 560 satellites in GEO, and about 250 in MEO and HEO combined.
The crowding of LEO is the result of growing government and private interest in space, policy changes, and cheaper satellite technology. In the 1960s, private companies could own satellites, but only the government could launch them. From 1984 onward, private companies could launch their own satellites. With the arrival of SpaceX in 2002, private enterprise entered space tech on a large scale; by the 2020s, BlueOrigin and Virgin Galactic were taking private citizens into space.
The stress
Even before satellites reach orbit, rocket propulsion subjects them to extreme forces, often loosening parts. Hypervelocity—27,500 kmph in LEO and 11,000 kmph in GEO—causes friction with residual molecules in space, creating extreme, localized heat. Rapid shifts in temperature—extreme heat when facing the sun and extreme cold in the shadows—can cause fragmentation. In GEO, radiation and electrostatic buildup add further problems.
The chances of pieces breaking off and adding to space junk are very high. Despite careful spacecraft design, space debris is inevitable.
The collision risk
The U.S. Space Surveillance Network (SSN) uses telescopes, radars, and space-based sensors to detect, catalog, and track artificial objects in orbit. Currently, it monitors about 47,000 objects. Given these numbers, the risk of collisions is obviously very high.
The 18th Space Defense Squadron, which tracks space objects and manages traffic, currently sends 600,000 conjunction data messages (CDMs) daily. These warnings alert satellite operators that a close approach with a space object is likely. In 2020, it sent an average of 200,000 CDMs daily. In 2025, SpaceX's Starlink constellation alone undertook 300,000 collision-avoidance maneuvers, averaging 40 evasions per satellite per year.
The risk of collision is no lower in GEO—despite fewer satellites—because it is populated by thousands of defunct satellites, rocket bodies, and debris. Military communications and early-warning satellites located there are particularly at risk.
In 2022, a Chinese spacecraft towed a dead satellite into the super-synchronous orbit, which is considered a graveyard for spacecraft. Because atmospheric drag is zero, objects remain permanently in this zone. Although China called its operation a debris-removal mission, concerns remain that China could use this capability to cause other countries' satellites to collide.
Satellites employ several collision avoidance strategies, some coordinated from the ground. They also use AI to avoid debris or adjust their surface to reduce drag caused by molecular friction. Laser-based deflection, thrusters, and tungsten clouds help them alter speed and drag to avoid collisions.
But the real problem is that there are too many objects to avoid. Because these objects move at extreme speeds, the relative speed of impacts can be 10–15 km per second. A tiny speck could destroy a satellite.
The Kessler syndrome
Collisions often trigger the Kessler syndrome, named for Donald Kessler, a NASA scientist. It is a vicious cycle in which one impact creates thousands of debris fragments, each further increasing the risk of collisions and more debris. The Kessler threshold, at which collisions produce debris faster than natural processes (such as solar activity and drag) can remove them, has already been crossed in heavily used bands.
Perhaps the most significant such collision was China's deliberate destruction of its weather satellite Fengyun-1C ASAT in 2007, which created 3,531 cataloged fragments. In 2009, the Iridium 33, a U.S. commercial satellite, collided with the Cosmos 2251, a defunct Russian military satellite, creating more than 2,000 large pieces. Both events produced thousands of equally dangerous smaller fragments.
Other major debris-generating events include the 1996 collision involving the Cerise satellite, in which a French microsatellite was struck by debris from an Ariane rocket; the 2021 collision of Yunhai-102 with debris from an old rocket; and the 2021 Kosmos 1408 ASAT test, in which Russia smashed a defunct satellite, creating more than 1,700 fragments that threatened the International Space Station (ISS).
Tracking and monitoring
In addition to the 18th Space Defense Squadron, which tracks objects in space using 30 radar and optical sensor sites worldwide, the EU Space Surveillance and Tracking and the ESA Space Debris Office in Germany also maintain records of debris and issue warnings. Other countries have their own systems.
Commercial operators have also entered the field: LeoLabs provides a phased-array radar network with tracking and warning capabilities; Anduril Industries, which recently acquired a global network of 400 optical telescopes, was contracted to upgrade the SSN.
The weakness
Unfortunately, none of the several U.N. treaties on space debris are binding. Even if they were, they wouldn't do much because they lack a unified approach. The Outer Space Treaty of 1967 established liability for damage, and the Liability Convention of 1972 created a compensation mechanism. But none of these, including obligations for active debris removal, are enforceable.
There is only so much capacity in space for objects. A cleanup is critical and overdue. Unless international law is strengthened—unlikely, given that nations can't agree on laws for the ocean bed and the poles—no one will be able to use space because we have filled it with junk.
Image generated by ChatGPT.
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