Kessler syndrome will kill orbital satellite constellations.
Self-destruction theory
First, a few statistics. Near space currently contains at least 34,000 pieces of man-made debris over 10 cm in size, over one million pieces between 1 and 10 cm, and 120 million pieces up to 1 cm. These particles travel at hypersonic speeds and are capable of piercing any armor, not to mention the thin walls of spacecraft. On Earth, space debris is being inventoried as best they can. The total mass of debris in orbit has been calculated to be 8,000 tons, and 26,000 objects posing the greatest danger have been cataloged. Everyone is extremely careful to avoid even individual pieces in orbit. Half of the cataloged objects are intact components, decommissioned satellites, upper stages remaining in orbit, and waste from space operations. The other half are fragments of varying sizes resulting from collisions or explosions in orbit. The most polluted altitudes are considered to be those between 600 and 1200 km and the geostationary orbit at 35,800 km.
The idea that orbit would eventually become crowded has been discussed since the last century. In 1978, American scientists Donald Kessler and Burton Court-Palais proposed a theory according to which
At a certain critical density of objects in low-Earth orbit (altitudes of 200–2000 km), any collision begins to generate new debris, which, in turn, triggers further impacts. The process becomes self-sustaining: debris production exceeds natural removal by atmospheric braking, and the orbital environment becomes a "cosmic garbage dump," making low-Earth orbit unsuitable for satellites, human missions, and even future launches for decades.
Things haven't reached collapse yet, but the first warning signs began ringing in the last century.
The first documented spontaneous destruction of an object in orbit occurred back in June 1961, when the second stage missilesThe Thor-Ablestar launch vehicle, which carried the Transit 4A vehicle, exploded due to the spontaneous combustion of residual propellant. This problem became systemic: between 1973 and 1981, at least seven similar explosions of Delta launch vehicle second stages were recorded.
In addition to the chemical instability of propellant components (such as aerosol-50), external influences and onboard system failures were also factors in the destruction. In November 1986, the third stage of the Ariane launch vehicle disintegrated at an altitude of 805 km, creating 463 large fragments; the disaster is believed to have been caused by a microparticle of space debris striking a pressurized fuel tank. Ten years later, in June 1996, the explosion of the fourth stage of the HAPS on the American Pegasus rocket resulted in the creation of approximately 150 fragments at altitudes of up to 1600 km. That same year, 1996, the first natural collision of an operational satellite with orbital debris occurred, followed by a similar incident in 2002.
The current phase of orbital failures is characterized by a growing range of critical factors. Traditional threats—fuel explosions and accidental collisions—have been supplemented by problems with power systems. Highlights include the 2015 incidents when nickel-cadmium battery explosions disabled the DMSP-F13 and NOAA-16 satellites. Thus, the evolution of space debris has evolved from isolated launch vehicle failures to mass fragmentation of spacecraft due to technical failures and intentional or accidental kinetic impacts.
However, the most critical contribution to orbital debris came from deliberate actions and accidental collisions of entire objects. In 2007, China tested an anti-satellite missile weapons (the destruction of the Fengyun-1C satellite) created the largest cloud in stories — more than 3500 cataloged fragments. In 2009, the first accidental collision between two satellites—the Russian Cosmos-2251 and the American Iridium 33—occurred, generating another 2300 large pieces of debris. The most recent major incident was the destruction of the Cosmos-1408 satellite in 2021, which generated over 1500 fragments threatening the safety of the ISS.
The debris problem is so serious that the scientific world has even coined the term "Collision Realization and Significant Harm Clock"—a cosmic "doomsday clock"—or CRASH Clock (Collision Realization and Significant Harm Clock). The calculations are complex, but one thing is clear: the CRASH Clock value is constantly decreasing. It currently stands at three days. What does this mean? If all satellites in low-Earth orbit suddenly lost control tomorrow (for example, due to an extreme solar storm or a global communications outage), the first catastrophic collision would occur, on average, within just 72 hours. There's a 50% chance that satellites will begin colliding with each other within 24 hours. For comparison, in 2018, the CRASH Clock was 164 days.
A few interesting facts: Satellites in mega-constellations pass within one kilometer of each other on average every 22 seconds. Modern orbital safety relies almost entirely on continuous autonomous orbital evasive maneuvers. Without them, a cascade effect (Kessler syndrome) can occur within a matter of days for perfectly healthy satellites.
Who is to blame and what to do
In December 2025, an incident occurred in low Earth orbit that became the catalyst for the largest reorganization in Starlink history. On December 10, the Chinese Earth observation satellite (2025-292A, manufactured by Chang Guang Satellite Technology), launched along with eight other payloads on the Kinetica-1 rocket from the Jiuquan Satellite Launch Center, passed just 200 meters from the Starlink-6079 satellite at an altitude of approximately 560 km. SpaceX classified the encounter as dangerously close Due to the lack of ephemeris exchange and coordination among Chinese operators, the Starlink satellite constellation has literally occupied altitudes between 340 and 600 km. The most populated echelon is between 540 and 570 km, which can now be called Elon Musk's echelon. Looking at the CRASH Clock index, it has decreased from 164 to 11 days between 2018 and 2023, precisely due to the launch of 10,000 Starlink communications satellites. Therefore, the close encounter between the Chinese remote sensing apparatus and Elon Musk's satellite is not surprising.
The Americans' reasoning is understandable—such low orbits allow for faster signal transmission and reception with less energy consumption. However, covering the entire Earth's surface at such altitudes requires a gigantic number of satellites. Ironically, Russia's Rassvet constellation is a good example: the first 16 satellites were launched into an 800-kilometer orbit at the end of March. The higher orbit means a slight delay, but only three to four hundred satellites would be needed for reliable coverage worldwide.
SpaceX isn't letting up. On January 1, 2026, Michael Nicholls, the aerospace company's vice president of Starlink engineering, announced that within a year, the company would lower approximately 4400 satellites (almost half of the 10 operational) from 550 km to 480 km. The goal is "improving space safety"Moreover, between June and November 2025 alone, Starlink satellites performed 148,696 evasive maneuvers, a significant portion of which were to avoid Chinese satellites and debris. Currently, there is no unified data exchange system between the US, Russia, and China regarding satellite constellation trajectories. Therefore, the likelihood of Kessler's hypothesis transforming from theoretical to practical is becoming increasingly tangible.
It seems the Americans acted responsibly when they lowered the orbits of their new satellites by 70 km. On the other hand, they themselves have filled the orbits above, beginning to occupy the lower orbits. And that's not the limit—in the future, Musk's company plans to increase the number of satellites to 30. Several similar projects are in the pipeline from OneWeb, Amazon, Telesat, and GW, each of which will add several thousand new satellites to orbit. And then there are meteoroids, solid space bodies smaller than asteroids. There's already a 50% chance of the Starlink constellation colliding with 15 meteoroids per year. This is a serious risk, threatening the uncontrolled and very rapid destruction of the satellite constellation in orbit.
Envisat-1
Starlink isn't the only one creating threats in space. Scientists are complaining about the Envisat satellite, launched in 2002 and retired 10 years later. It's a hefty toy—the satellite weighs over 8 tons. Its orbital altitude is 800 km, with an inclination of 98,6°. The satellite's ballistic lifespan in this orbit is 150 years. How many times in 150 years will something hit it, or will it destroy something in its path? The question is rhetorical.
What should we do? There are currently no real solutions to the situation. All known ones are pure science fiction. For example, launching robots into orbit to clean up space—using nets, harpoons, cables, lasers, or simply manipulators. Another option is to slow down progress and stop the massive pollution of near space with satellite communications devices. Currently, little more is being done to achieve this.
The onset of Kessler syndrome will make space launches impossible for decades, requiring a radical "reset" of near-Earth space. One key strategy for clearing low orbits of small debris under these conditions could be the "Tungsten Plow" project. This method utilizes clouds of tungsten dust, which, by creating artificial drag, will cause microfragments of debris to lose speed and burn up in the atmosphere. A blissful future in space will dawn, very reminiscent of the world before October 4, 1957.
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