A Behemoth in a Failing Orbit
The International Space Station (ISS) is, without qualification, the largest and most complex object humanity has ever placed in space. It is a sprawling, 109-meter-long metropolis in orbit, a $150 billion testament to engineering and international cooperation. Weighing more than 420,000 kilograms (over 925,000 pounds), its mass is equivalent to more than 330 automobiles. Its acre-spanning solar arrays, covering 2,500 square meters, power a pressurized volume larger than a five-bedroom house, which has been continuously inhabited by astronauts since November 2000.
But this city in the sky is in a constant, losing battle with gravity.
The station doesn’t just float; it falls. Flying in Low Earth Orbit (LEO) at an average altitude of 400 kilometers, it still skims the imperceptibly thin, uppermost tendrils of Earth’s atmosphere. This tenuous gas creates a persistent, gentle friction – a constant atmospheric drag. This drag acts as a brake, continuously slowing the station and causing it to lose altitude. Without regular intervention, the ISS’s natural orbital lifetime is only one to two years; it would simply fall back to Earth on its own.
To counteract this decay, the station requires regular “reboosts.” These are propulsive maneuvers, fired either by its own thrusters or those of docked cargo vehicles like the Russian Progress, that push the entire 925,000-pound structure back up to a safe altitude. The ISS is not a static object; it is a dynamic system in a state of managed failure – a continuous, high-speed fall, perpetually corrected by propellant.
This perpetual maintenance cannot last forever. The primary reason for the station’s retirement is age. Assembly began in 1998. The earliest modules, which form the station’s core, are now decades old, operating far beyond their originally certified lives. The entire structure is showing signs of fatigue. It endures a brutal existence, cycling between the 200°C (392°F) bake of direct sunlight and the -200°C (-328°F) freeze of shadow every 45 minutes. This relentless thermal cycling, coupled with vibrations from docking vehicles and a constant peppering from tiny meteoroids, has weakened its structure.
In recent years, astronauts have spent increasing amounts of time hunting for persistent air leaks, and component degradation is a growing concern. A 2024 report from NASA’s Office of the Inspector General questioned the station’s ability to continue operating safely for five more years.
The international partners – the United States, Russia, Europe, Japan, and Canada – have agreed to extend operations until 2030. After that date, the risk of a catastrophic, unrecoverable failure – a major depressurization, a structural rupture, a systems-wide breakdown – becomes unacceptably high.
Decommissioning isn’t a choice; it’s a physical inevitability. The only question is whether that return to Earth is controlled or chaotic.
The public often asks a reasonable question: “Why not just push it into a higher, permanent orbit?” This “graveyard orbit” option is standard practice for satellites in high, geosynchronous orbits. But for the ISS, it’s not a viable solution. The sheer amount of propellant needed to move a 420-ton object up against Earth’s gravity, rather than down with it, is staggering. Even if it were possible, it would be an act of significant irresponsibility. Abandoning the ISS at a higher altitude would just turn it into the single largest, most dangerous piece of space debris ever created, a 925,000-pound hazard that would threaten every future mission for centuries.
For these reasons, NASA and its partners have concluded that a controlled, targeted deorbit is the “safest and only viable method” to retire this historic symbol of science and collaboration. The plan is not to shut the station down; it’s a pre-emptive, controlled surrender to an unwinnable fight against physics and material fatigue. It is a race to safely dismantle the station before it dismantles itself.
The Plan: A Controlled Plunge into the Planet’s Emptiest Corner
The primary objective during the ISS deorbit operation is a “responsible re-entry.” This means ensuring that the massive structure comes down in an unpopulated area, posing no risk to people or property. The chosen destination is a specific, lonely spot in the South Pacific Ocean.
This location is known colloquially as “Point Nemo,” or the “spacecraft cemetery.” It is the oceanic pole of inaccessibility – the point on Earth’s surface farthest from any landmass. It is a vast, empty patch of ocean, the same remote area successfully targeted for the controlled reentries of hundreds of uncrewed cargo ships and, most famously, Russia’s 130-ton Mir space station in 2001.
The deorbit maneuver itself will be a precise, multi-stage process. It’s not a simple case of “hitting the brakes.” The operation will begin after the final crew has safely departed and returned to Earth. Ground controllers will then begin to intentionally lower the station’s altitude.
For the initial part of this descent, they will use atmospheric drag as a “free” propellant, carefully managing the station’s orientation to let the thin atmosphere do the work of pulling it down. This “natural decay” phase saves an enormous amount of propellant and gets the station into position for the final, critical maneuver.
Once the station reaches the correct altitude and is aligned with the final target ground track – a path that ensures its trajectory passes directly over Point Nemo – operators will command the large, final re-entry burn. This is the “final push.” A dedicated spacecraft, docked to the ISS, will fire its engines in a powerful, sustained burn. This burn provides the precise force needed to slow the station, steepen its angle of descent, and propel it through the atmosphere into a targeted debris footprint. The goal is to contain all surviving debris within a footprint 6,000 kilometers long or less, a swath of ocean far from any island, shipping lane, or coastline.
The Tool: A New Vehicle for a New Task
This complex operation hinges on a single, powerful “tow truck.” The original deorbit plan, first conceived in the late 1990s, was to use three Russian Progress cargo spacecraft. These autonomous, disposable ships are the station’s workhorses, and their thrusters are regularly used for reboosts. The original idea was to dock three of them, fully fueled, and use them in concert for the final braking burn.
That plan has been scrapped.
In the decades since, NASA and its partners have concluded that a far more robust, reliable, and powerful solution is required. The station’s own aging propulsion systems are not up to the task, and the complexity of coordinating three separate vehicles for a single, perfect burn introduced too many points of failure.
In its place, NASA is procuring a new, dedicated spacecraft: the U.S. Deorbit Vehicle (USDV). In 2024, the agency awarded a contract, valued at approximately $1.5 billion, to SpaceX to develop and deliver this vehicle. It will be a new spacecraft, based on the company’s flight-proven Dragon capsule, but heavily modified for this one-of-a-kind mission. It will be a propulsive powerhouse, equipped with 46 Draco thrusters, designed to provide the massive, controlled thrust needed to steer a 420-ton giant to a precise point on the globe.
This procurement is not a “service,” like the commercial crew flights that taxi astronauts to the station. This is a traditional development contract. SpaceX will build and launch the USDV, but NASA will “take ownership” and “operate it” throughout the entire final mission.
This $1.5 billion price tag is a clear-eyed risk mitigation investment. It represents a fundamental pivot from the original plan of international reliance (on Russian Progress vehicles) to one of singular, national control. It is a tacit admission that for this final, safety-critical operation, NASA cannot leave the outcome to chance. The geopolitical stability of the international partnership, and the guaranteed reliability of partner hardware, can’t be assumed for a mission that will take place at the end of the decade. NASA is paying $1.5 billion for a single-use “chariot” because the cost of failure – an uncontrolled reentry – is infinitely higher.
This solution creates its own single, massive point of failure. The USDV will be a brand-new design. It will launch, dock with the ISS, and then be asked to perform its complex, high-stakes mission flawlessly. It must function perfectly on its very first flight. There are no second chances.
How Control Is Lost: The Anatomy of a Deorbit Failure
The NASA plan is robust, but it is not infallible. The ISS is arguably the most complex machine ever built, and the deorbit operation will be the most complex “disposal” ever attempted. A failure wouldn’t be a single event, but a cascade. The “worst-case scenario” begins when one of several things goes wrong, causing mission planners to lose their grip on the 420-ton station.
The Station Won’t Steer: Loss of Attitude Control
A controlled deorbit is, at its most basic level, a steering problem. The USDV must push the ISS in a precise direction at a precise time to hit a target thousands of miles away. But to do this, the station’s “attitude” – its orientation in three-dimensional space – must be absolutely stable. Firing 46 thrusters on a station that is tumbling end-over-end is useless. It’s like flooring the gas pedal in a car that’s skidding on ice: you get a lot of force, but it’s not going in the direction you want.
This is not a hypothetical risk. The International Space Station has lost attitude control multiple times.
These incidents, detailed in a NASA Office of the Inspector General report, serve as a chilling “smoking gun” for what could go wrong.
On July 21, 2021, the new Russian “Nauka” module docked to the station. Shortly after, it “inadvertently fired its thrusters” for 10 agonizing minutes. The uncommanded thrust sent the entire 420-ton station into a violent, uncontrolled tumble. The station became “inverted,” losing its connection to communications satellites. NASA declared a “spacecraft emergency.” It took ground controllers in Houston and Moscow, working frantically, a full hour to counter-rotate the station using thrusters from other docked vehicles and regain control.
Just three months later, in October 2021, it happened again. During a “scheduled thruster firing test” on a docked Russian Soyuz spacecraft, the engines “unexpectedly continued” to fire after the test window closed. Once again, the station was pushed off-axis and lost attitude control. This time, it took 30 minutes to fix.
During the final deorbit, an hour-long – or even 30-minute – loss of control would be an unmitigated catastrophe. The station’s primary steering system, its four massive Control Moment Gyroscopes (CMGs), are giant, 220-pound spinning flywheels that keep it stable. But these gyros become less effective as the station descends into the thicker atmosphere (below 220 kilometers). At that low altitude, the station must rely on propulsive thrusters for attitude control, precisely when it is most vulnerable.
A “Nauka-like” event during the final burn – a software glitch, a stuck valve, a faulty command – is the deorbit’s single greatest vulnerability. An uncommanded thruster firing from an old Russian module could easily “fight” the USDV’s steering inputs, overpowering it and sending the station tumbling off its planned trajectory, guaranteeing an uncontrolled reentry. The deorbit plan relies on a complex, aging, multi-national patchwork of hardware and software working in perfect harmony, one last time. The 2021 incidents prove that these systems can, and do, fight each other.
A Strike from Above: The MMOD Threat
The ISS operates in what is essentially a high-speed shooting gallery. It is under constant bombardment from Micrometeoroids and Orbital Debris (MMOD) – a cloud of man-made and natural particles. The station is the “most heavily protected vehicle in Earth orbit,” its vital modules wrapped in “Whipple shields.” These are multi-layered blankets of high-strength fabric and metal designed to break up an impacting object, dissipating its energy.
But this shielding has limits. It is designed to reliably stop particles up to about 1 centimeter in diameter.
The real danger comes from the “mission-killer” projectiles: debris larger than 1 centimeter but too small to be tracked by ground-based radar. The station can (and frequently does) fire its thrusters to maneuver out of the way of known, trackable objects. But it is blind to these smaller, untrackable “bullets.”
At orbital speeds of over 17,000 miles per hour, the kinetic energy is almost unimaginable. A 10-centimeter (4-inch) piece of debris, roughly the size of a softball, impacts with the destructive energy of 7 kilograms (15 pounds) of TNT.
A NASA report on the station’s end-of-life plan states that a “critical or catastrophic failure could occur with little or no warning,” necessitating an “immediate safe disposal.” A deorbit failure could be triggered by a single, unlucky MMOD strike.
Imagine a piece of debris from a defunct 1980s rocket striking the USDV after it has docked for the final maneuver. An impact on one of its propellant tanks, its flight computer, or its cluster of 46 thrusters would be an instant mission kill. The $1.5 billion “tow truck” would be disabled, leaving the station without its engine.
Worse, a sufficiently large impact could cause a “total space station breakup,” triggering the other worst-case scenario: a catastrophic fragmentation in orbit.
The deorbit plan itself, which stretches operations to 2030 and then involves a slow, multi-month decay, paradoxically maximizes this risk. Every additional day the 420-ton station remains a target, it is a gamble against a debris environment that is only getting more crowded. NASA is betting it can execute the controlled deorbit before the increasingly hazardous LEO environment executes an uncontrolled one.
Hardware, Software, and Solar Storms
Beyond attitude control and debris strikes, a host of other single-point failures could doom the operation. The USDV must work on its first flight. A failure of its avionics, a leak in its propellant lines, or a failure of its thrusters to ignite would be unrecoverable. The station’s own aging propulsion systems, needed for the initial descent maneuvers, are also a risk. The Russian segment’s thrusters are already operating years beyond their original certified lives.
Even if the hardware works, the command link is a vulnerability. The final deorbit burn must be commanded from the ground. If that link is lost at the critical moment, the station is left “deaf” and will simply continue on its path, a runaway train with no one at the switch. This loss of signal was a key marker of the Columbia disaster as it broke apart over Texas. While Columbia’s blackout was caused by physical disintegration, a simple communications antenna failure or ground station-glitch could have the same result for the ISS.
But the most terrifying failure mode is one that combines all these risks: a powerful solar storm.
A severe Coronal Mass Ejection (CME) – a massive eruption of charged particles from the Sun – is a major, unpredictable threat. The powerful solar storm of May 2024 provided a perfect dress rehearsal for the kind of chaos one can cause.
A solar storm could create a “perfect storm” of cascading failures:
- Increased Drag: The CME’s energy slams into Earth’s atmosphere, heating it and causing it to expand. This sudden, massive increase in atmospheric drag would be like the ISS hitting an “air pocket.” It would pull the station down faster and off-course, completely ruining the precise trajectory calculations needed to hit Point Nemo.
- Electronic Failure: The storm’s high-energy particles can fry sensitive electronics. During the May 2024 event, NASA’s ICESat-2 satellite’s “attitude control” systems became “questionable,” forcing the entire satellite into a protective “safe mode.” If this happened to the USDV’s flight computer or the ISS’s own systems during the final burn, it would be instantly uncontrollable.
- Communications Blackout: Solar flares create severe “ionospheric anomalies” that can black out high-frequency radio communications for hours.
One can easily imagine a scenario where a massive CME is detected, heading for Earth, just as the ISS is in its final, uncrewed descent. The charged particles arrive, frying the USDV’s primary flight computer. Simultaneously, the atmospheric drag pulls the station off-track. Ground controllers in Houston see the failure and try to send backup commands, but the ionospheric disturbance has already caused a total communications blackout.
The result: the 420-ton station is left tumbling, deaf, and completely uncontrolled, hurtling toward an unpredictable reentry, all from a single solar event.
Consequence One: The Uncontrolled Reentry
This is the first of the two worst-case scenarios. A failure has occurred – the USDV’s engines didn’t fire, attitude control was lost, or a solar flare sent the station tumbling – and now, the 925,000-pound behemoth is on its own, coming home in a chaotic, fiery plunge.
The Physics of a Tumbling Giant
An uncontrolled reentry is one in which a spacecraft’s orbit decays naturally from atmospheric drag, with no propulsive steering. Its final path is left entirely to chance, dictated by complex physics.
The key to predicting any reentry path is a value called the “ballistic coefficient” (BC). This is a simple ratio of an object’s mass to its aerodynamic drag. An object with a high BC – like a dense, heavy cannonball – will punch deep and fast into the atmosphere. An object with a low BC – like a light, broad feather – will slow down very quickly at a high altitude.
The problem is that the International Space Station is not a simple cannonball. It’s a 109-meter-long, asymmetrical, complex structure of trusses, modules, and 16 massive solar arrays. In an uncontrolled descent, it will not be a “blunt body”; it will be “tumbling” end over end.
This tumbling motion means its shape, and therefore its drag, is constantly changing. One moment, it presents its narrowest profile to the atmosphere; the next, it presents its full, broad side. This “time-varying ballistic coefficient” makes its trajectory “nearly impossible” to model accurately. Ground controllers would be able to do little more than guess. They would not know, with any meaningful precision, when or where it would ultimately land. The error window wouldn’t be in miles, but in thousands of miles.
The station would not hit the ground as a single, intact object. The reentry would be a “breakup sequence” occurring over several minutes.
- Altitude 90-95 km: The first to go would be the most fragile and high-drag components. The massive solar arrays, with their 109-meter span, would be ripped from the main truss by the mounting aerodynamic forces.
- Altitude 72-84 km: As the station plummets deeper, the main breakup begins. The intense, 7,000-degree Fahrenheit heat of atmospheric compression will melt the thin aluminum skins of the pressurized modules. With their outer shells vaporized, the station will disintegrate as the aerodynamic forces “exceed the allowable structural loads,” shattering the station into its constituent parts.
The best – and most troubling – historical parallel for this scenario is not the successful Mir deorbit, but the 1979 reentry of NASA’s first space station, Skylab.
NASA tried to control Skylab’s descent. It was a semi-controlled reentry. As the 76-ton station’s orbit decayed, engineers sent a final command to make it tumble, hoping to fine-tune its landing spot in the remote Indian Ocean. They missed. While large chunks did splash down in the ocean, a significant amount of debris also littered populated areas of Western Australia. No one was injured, but the event was a global embarrassment and a stark lesson in the unpredictability of reentry.
The International Space Station is over five and a half times more massive than Skylab. If NASA couldn’t perfectly steer a 76-ton station in 1979, the chances of an uncontrolled 420-ton station landing “safely” in an ocean are effectively zero.
A Debris Swath Across Continents
The debris from the breakup will not land in a single, neat crater. It will be scattered in a “long, thin ground footprint.” As the station breaks apart at high altitude while still traveling at thousands of miles per hour, its hundreds of fragments will continue on their trajectory, fanning out as they fall.
This creates a “carpet-bombing” effect. We have historical data on what this looks like.
- The controlled reentry of the Mir station, which was steered to be as compact as possible, still had a predicted debris footprint 3,000 to 4,000 kilometers long and 100 to 200 kilometers wide.
- The much smaller, 12-ton ATV-1 cargo vehicle, on its reentry, left a confirmed footprint 817 kilometers long and 30 kilometers wide.
The debris swath from a tumbling, uncontrolled ISS would be staggering. It would create a trail of destruction potentially thousands of kilometers long and hundreds wide, capable of stretching across multiple countries or an entire continent.
The Ground Track: A 90% Gamble
This is the most terrifying variable: where on Earth could this debris swath land?
The ISS orbits at an inclination of 51.6 degrees. This specific orbit was chosen in the 1990s as a political and engineering compromise, as it was the most efficient path reachable by both the American Space Shuttles launching from Florida and the Russian rockets launching from Kazakhstan.
The direct, unavoidable consequence of that decision is that the station’s ground track passes over 90% of the Earth’s populated area.
The only “safe” zones are the extreme northern and southern latitudes (above 51.6° North and below 51.6° South). Every other region of the planet is a potential impact zone. The station’s path passes directly over most of North America, all of Europe, most of Russia, all of Japan, China, India, Africa, and South America. Major cities like New York, London, Paris, Moscow, and Beijing are all on the potential ground track.
This creates a terrifying game of global roulette. While 70% of the Earth’s surface is water, and the risk to any one individual is statistically infinitesimal (less than one in a trillion), that statistic is dangerously misleading.
The international standard for an acceptable casualty risk for a single uncontrolled reentry is 1-in-10,000. That is the probability that one person, anywhere on Earth, will be killed. An uncontrolled reentry of the 420-ton ISS, with its debris swath stretching across continents and its ground track covering 90% of the world’s population, would violate this safety standard by orders of magnitude. The true risk is not the low-probability event of a single person being hit, but the high-probability event of a massive, high-energy fragment striking a high-density target, like a city or critical infrastructure.
What Hits the Ground
The ISS was not designed with a heat shield. During the violent reentry, most of its hardware, including the aluminum skins of its modules, will burn up or vaporize.
But not everything.
Analysis of past reentries, like Skylab and Mir, shows that 20% to 40% of a large spacecraft’s mass can survive the fiery plunge and impact the Earth.
For the 420,000 kg International Space Station, that is 84,000 to 168,000 kilograms (roughly 92 to 185 tons) of debris.
To put that in perspective, the surviving debris from the ISS would weigh more than the entire mass of the Skylab or Mir stations at their own reentries.
What survives? The most dense, robust, and heat-resistant components. These pieces act as “heat sinks.” Their high melting points and high heat-of-fusion (the energy required to melt them) mean the atmosphere doesn’t have time to destroy them before they reach the ground.
- The Integrated Truss Structure: The station’s 100-meter-long “backbone.” This is a massive, dense structure of aluminum, steel, and titanium. NASA’s own analysis explicitly states that these dense truss sections are expected to survive.
- NORS High-Pressure Tanks: The station’s oxygen and nitrogen tanks. These are “seriously beefy” components, each about 1 meter long and weighing 100 kg (220 pounds). They are designed to hold gas at 6,000 psi and are virtually indestructible during reentry.
- Control Moment Gyroscopes (CMGs): The heart of the station’s attitude control. Each of the four CMGs contains a 98-kilogram (220-pound) solid steel flywheel that spins at 6,600 rpm. These massive steel discs will survive.
- Docking Ports and Mechanisms: The heavy, robust rings and hatches that join modules, built of steel and titanium to withstand repeated, high-load dockings.
- Any Dense Metal: Pressure vessels, battery components, and any hardware made of stainless steel, titanium, or beryllium are all known survivors. Tumbling titanium spheres from old rockets are found on the ground “totally intact.”
Damage, Impact, and Toxicity
These surviving fragments won’t be “charred” embers; they will be high-velocity projectiles. While they will have slowed from their 17,000 mph orbital speed, their terminal velocity can still be hundreds of miles per hour.
The kinetic energy is the real killer. A 10-centimeter piece of debris has the impact energy of 7 kilograms of TNT. A 100-kg NORS tank or a 98-kg CMG flywheel would impact the ground with enough force to obliterate a building, penetrate a reinforced concrete bunker, or sever a bridge. A multi-ton section of the main truss would be unrecognizable from any conventional weapon.
This is the “secondary risk” that analysts fear. A single fragment striking one of the 92 nuclear power reactors in the United States, or a large hydroelectric dam, could trigger a cascading regional disaster far worse than the impact itself. These facilities are hardened, but not against 10-ton truss segments falling from orbit.
Finally, the surviving debris will be toxic. The station is full of hazardous materials.
- Ammonia: The station’s complex cooling system circulates large quantities of highly toxic ammonia.
- Hydrazine: Propellant tanks on the Russian segment and visiting vehicles contain hydrazine, a common rocket fuel. Hydrazine is “acutely toxic.” The National Fire Protection Association gives it the maximum “4” health rating, placing it in the same category as sarin or VX nerve gas. It is also hypergolic, meaning it spontaneously explodes on contact with oxygen, and can be detonated by a simple physical shock.
A surviving, intact propellant tank that lands in a populated area is a nightmare scenario: a chemical, toxic, and explosive bomb all in one.
Consequence Two: The Orbital Catastrophe
The uncontrolled reentry is a terrifying scenario, but it has a second, and perhaps even worse, twin. This is the other worst-case scenario, in which the station does not fall to Earth in a (relatively) short-lived event, but instead fragments in orbit, creating a permanent disaster that would change humanity’s relationship with space forever.
The ISS as a Debris Bomb
This scenario isn’t a slow decay. It’s a sudden, violent event. The trigger could be a catastrophic MMOD strike from an untrackable piece of debris, striking a high-pressure tank or a critical structural joint. It could be an onboard explosion – a faulty battery, an unvented propellant tank, or a chain reaction from a smaller fire.
The result is the same: the 420-ton station instantly disintegrates.
This would be, by an order of magnitude, the single worst “fragmentation event” in human history. The 2007 Chinese anti-satellite test, which destroyed a one-ton weather satellite, was considered a global catastrophe; it created over 3,000 trackable pieces of debris and hundreds of thousands of smaller, lethal fragments. The 2009 collision between an active Iridium satellite and a defunct Cosmos satellite was similarly devastating.
The fragmentation of the ISS would be hundreds of times worse. The 420-ton mass would instantly create a cloud of hundreds of thousands, if not millions, of new projectiles. Orbital mechanics simulations show that this debris cloud wouldn’t stay in one place; it would rapidly expand, enveloping the entire 400-kilometer orbital altitude in a cloud of hypervelocity shrapnel.
Igniting the Kessler Syndrome
This scenario has a name: the Kessler Syndrome. First proposed by NASA scientist Donald Kessler in 1978, it describes a “chain reaction” theory for orbital debris.
The syndrome describes a scenario in which the density of objects in LEO becomes so high that collisions, which were once rare, become inevitable. The problem is that each collision creates a cloud of new debris, which in turn dramatically increases the probability of more collisions.
This creates a cascading, runaway effect. Debris hits a satellite, creating more debris. That new debris hits other satellites, creating even more debris. Eventually, the chain reaction becomes self-sustaining and exponential. The orbital environment becomes unusable.
Many space debris experts believe the LEO environment is already at this “tipping point.” We are, perhaps, one major event away from an irreversible cascade.
The catastrophic fragmentation of the 420-ton International Space Station could be that event. Adding this much mass to the debris field, at the critical 400-kilometer altitude, would be the “nail in the coffin.” It would inject so much new debris into the system that it would almost certainly ignite the Kessler Syndrome, making the chain reaction unstoppable.
The Economic and Social Fallout
This is not a slow-motion disaster. The consequences would be immediate and apocalyptic for our modern, space-dependent civilization.
The new ISS debris cloud, traveling at 17,000 mph, would begin to “sandblast” every other object in its orbital neighborhood. This would cripple modern life. We would lose, perhaps in a matter of months or years:
- Weather Forecasting: The satellites that monitor hurricanes, typhoons, and daily weather patterns would be destroyed.
- Climate Monitoring: All Earth-science missions monitoring ice caps, deforestation, and sea-level rise would go dark.
- Global Communications: LEO-based internet and communication networks, like Starlink and OneWeb, would be the first to be shredded, as they share the same orbital space.
- GPS and Navigation: While GPS satellites are in a much higher orbit, the ability to launch replacements would be gone. The GPS, timing, and navigation services that underpin the entire global financial system, logistics, shipping, and agriculture would be threatened.
The multi-billion-dollar space economy would be over. Investment would halt. But the most significant consequence would be this: we would be trapped on Earth. It would become impossible to safely launch new satellites, new telescopes, or human missions. The debris field would be so dense that any rocket ascending through it would have a high probability of being destroyed.
This “orbital catastrophe” holds one final, tragic irony. The most immediate and certain victims of an ISS fragmentation would be the other space stations. The Chinese Tiangong station flies at a similar 400-km altitude. The planned U.S. commercial stations from Axiom, Blue Origin, and Starlab – the very platforms NASA is counting on to replace the ISS – are all designed to operate in this same orbital “neighborhood.”
An orbital breakup of the ISS would create its debris cloud at this exact altitude. The cloud would almost certainly destroy Tiangong – a geopolitical disaster in itself – and would wipe out the entire U.S. commercial space industry before it even begins. It would be a case of the “old” destroying the “new” in the most literal, destructive way possible.
The Aftermath: Legal and Geopolitical Reckoning
In the wake of an uncontrolled reentry, after the debris has fallen and the fires are out, the second, slower catastrophe begins: the legal and geopolitical reckoning. If a 10-ton piece of the ISS truss destroys a suburb of Rio de Janeiro, who is responsible? Who pays?
Who Pays for the Damage?
The law for this scenario is surprisingly clear, established decades ago during the Cold War. The 1967 Outer Space Treaty and, more specifically, the 1972 Convention on International Liability for Damage Caused by Space Objects (the “Liability Convention”) provide the legal framework.
The key phrase is “absolute liability.”
Article II of the Liability Convention states that a “launching State shall be absolutely liable to pay compensation for damage caused by its space object on the surface of the earth.”
“Absolute liability” is a simple, brutal legal standard: fault doesn’t matter. It doesn’t matter if the deorbit failure was caused by an “act of God” like a solar flare, or an unavoidable MMOD strike. The legal argument is simple: you launched it, it caused damage, you pay for it. This is different from damage in space (a satellite hitting another satellite), which is governed by a more complex “fault-based” standard. For damage on Earth, there is no “it wasn’t our fault” defense.
This is not just theory. The convention has been used once. In 1978, the nuclear-powered Soviet satellite Kosmos 954 failed, and its reactor reentered over Canada, scattering radioactive debris across the Northwest Territories. Canada filed a formal claim against the Soviet Union under the Liability Convention. The USSR, accepting the principle of absolute liability, eventually paid Canada millions in compensation.
Joint and Severally Liable
The Kosmos 954 incident was simple: one country’s object hit one other country. The ISS is a legal and political nightmare. It is not one country’s object. It is a joint program between five partners: NASA (US), Roscosmos (Russia), JAXA (Japan), the European Space Agency (ESA), and the Canadian Space Agency (CSA).
The authors of the 1972 Liability Convention, anticipating simple joint launches (e.g., two countries sharing one rocket), included Article V. This article states that when two or more states “jointly launch a space object,” they shall be “jointly and severally liable” for any damage.
This legal term – “jointly and severally” – is a geopolitical time bomb.
In this context, it means that a state that suffers damage (for example, India, if a CMG lands on the Taj Mahal) can demand 100% of the compensation from any or all of the partners. India would not have to figure out which piece of the station hit it or which partner was at fault. It could, and would, send the entire bill to the United States alone.
It would then be up to the U.S. to try and get reimbursement from its partners, as outlined in the ISS Intergovernmental Agreement.
Now, imagine the most likely failure scenario: the deorbit fails because of a Russian component failure, like the 2021 Nauka incident. The resulting debris lands in an allied nation, like Canada. Under the “joint and several” clause, Canada would be fully within its rights to sue the United States (its ally and partner) for 100% of the damages, knowing it’s more likely to get the money.
This would put the U.S. in the politically impossible position of having to pay billions in compensation for a catastrophe caused by a Russian failure, and then try to collect that money from Moscow. The 1972 Liability Convention, designed to protect victim states, is almost perfectly engineered to create a diplomatic crisis and shatter the ISS partnership in the aftermath of a disaster.
Summary
The International Space Station stands as one of humanity’s greatest achievements in science and, perhaps more importantly, in international collaboration. For decades, it has been a symbol of what nations can accomplish when they work together, a peaceful outpost in the sky.
But like all great structures, its time is coming to an end. Its operational life is finite, and it must return to Earth. The international partners, led by NASA, are not taking this challenge lightly. They have developed a robust, detailed, and expensive plan to ensure this return is “safe and responsible.”
The development of the $1.5 billion U.S. Deorbit Vehicle is a testament to how seriously this engineering challenge is being taken. It is the single most important tool to prevent the very worst-case scenarios – an uncontrolled reentry over populated land or a catastrophic breakup in orbit.
The risks are not trivial. The station is an aging, complex machine operating in an increasingly hazardous environment. A failure of hardware, a glitch in software, a strike from debris, or a blast of solar weather could all trigger a catastrophe.
But the plan is designed to manage these risks. The goal is to ensure that this historic symbol of scientific partnership concludes its mission not with a global crisis, but with a final, planned, and solitary splashdown in the most remote waters of the world.
