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← Mission control № 02 · April 24, 2026

KESSLER SYNDROME

Space junk now grows even if nobody launches

Last year one company's satellites dodged 300,000 times. The junk you never see has never once been cleaned up.

The primer

Low Earth orbit: the band 160 to 2,000 km up. Every collision there makes thousands of fragments, so each can start the next. In 2025 the agency that counts them said the chain has started.

PublishedApril 24, 2026
Reading time4 min
Sources12 cited
DeskMission control
The dekTwo tests, two altitudes. One cloud cleared. One stays past 2100.
— 01
WHAT CHANGED

It has already started

Zero new launches, and the debris total still rises.

What most people think

Space junk is a problem for later. Stop launching and the sky slowly clears itself.

What the data shows

0new launches

Even at zero new launches, the total still climbs. Thin air up there drags fragments down, but break-ups add them faster than it can.

ESA, the agency that counts what is in orbit, wrote this in its 2025 report.

Zero new launches, and the debris total still rises.

In plain terms Two panels: on the left what most people assume, on the right what the numbers show, with the one figure that settles it.Source · ESA Space Environment Report 2025

— 02
THE RECORD

Six break-ups wrote today's orbit

Even with nothing new going up, the debris count still rises. Here is where most of it came from.

Jan 11 2007
Fengyun-1C · China's test
A missile destroyed a dead weather satellite at 865 km.
Feb 10 2009
Two satellites collide
The first time two whole satellites ever hit each other.
Mar 27 2019
Mission Shakti · India's test
Fired deliberately low, at 283 km. About 125 fragments.
Nov 15 2021
Cosmos 1408 · Russia's test
The crew on the space station sheltered in their capsules.
Jun 26 2024
An old satellite breaks up
A 6-tonne dead satellite came apart on its own. 180+ pieces.
Aug 6 2024
A rocket stage fragments
It had just released a batch of new satellites.
About a tenth of 2025's near-miss risk came from this.

Six break-ups. Three were deliberate tests, one a collision, two just came apart.

In plain terms The key events in order down a rail, with coloured dots flagging the pivotal moments.Source · ESA Space Debris Office, with US Space Command and SpaceNews

— 03
THE GROUND RULES

Three words, said plainly

Six dates, one piece of physics under all of them. Three words carry the rest.

Kessler syndrome
One crash makes debris, which means the next crash gets likelier. Two scientists at NASA modelled it in 1978.
Collision avoidance
The satellite fires its thrusters and moves. Fuel burned dodging is fuel it cannot use working.
Decay
Thin air up there drags a fragment down until it burns. Go higher and there is almost no air left.

Source · Kessler and Cour-Palais 1978, with ESA

— 04
WHERE IT BROKE

Altitude decides how long the junk stays

Why did one test's cloud vanish while another's is still up there? The answer is the height it happened at.

Five break-ups by altitude. The lowest cleared in two years. The highest clears after 2100.km
Fengyun-1C · 2007 865 865 km. Nothing slows it. Still there after 2100.
Rocket stage · 2024 800
Two satellites · 2009 789
Cosmos 1408 · 2021 480
Mission Shakti · 2019 283 283 km. The air still reaches. Gone in two years.

Five break-ups by altitude. The lowest cleared in two years. The highest clears after 2100.

In plain terms Each bar is one break-up, drawn at the altitude it happened. A longer bar means higher up.Source · NASA Orbital Debris Program Office, LeoLabs and ESA

— 05
THE ANNUAL COUNT

The agency's own word for it: runaway

Space-agency prose is usually careful. Here is the 2025 report saying it plainly, and not in the future tense.

“Even without any additional launches, the number of space debris would keep growing, because fragmentation events add new debris objects faster than debris can naturally re-enter the atmosphere, and active debris removal is required to prevent the runaway chain reaction known as Kessler syndrome.”

— European Space Agency · Space Environment Report 2025

In plain words: stop every launch tomorrow and the count still goes up, because things break apart faster than the air pulls them down. What comes next is the bill.

Source · ESA Space Environment Report 2025

— 06
THE RENT

Dodging is now a full-time job

That chain has a price, and it is already being paid. Start with one company's share of it.

Starlink made more than 300,000 avoidance moves in 2025.

Starlink course changes in 2025

300,000+

A move is ordered when the odds of a hit pass 3-in-10-million.

  • at least 34 every hour, all year long 300,000 divided across the year's hours

  • three lakh course changes, one fleet, one year the same figure, said in lakh

Starlink made more than 300,000 avoidance moves in 2025.

In plain terms One number, large, and beside it the everyday things it equals, so the size can be felt rather than read.Source · FCC orbital-debris reports and Jonathan's Space Report

— 07
SIX READINGS

What sharing the orbit costs now

Three lakh dodges is one company's bill. Here is what the rest of the sky already costs.

Sharing low orbit · 1998 to 2026
10,074
Starlink satellites in orbit
As of March 20, 2026. Crossed 10,000 on March 17.
0
pieces of debris ever removed
One mission flew within 15 metres in 2024, then left.
~10 %
of all near-miss risk in 2025
A near miss is a dangerously close pass. All from one rocket-stage break-up, August 2024.
39
space-station debris dodges since 1998
The last was April 30, 2025, dodging a 2005 fragment.
7,473
objects newly tracked in 2024
Break-ups are part of it.
$150,000
largest fine for leaving a satellite
One operator, one satellite, 2023. The only case so far.

Sharing low orbit · 1998 to 2026

In plain terms The headline numbers from the story, each with its unit and a one-line note.Source · FCC, NASA, Astroscale and Jonathan's Space Report

— 08
THE SHARED BILL

You pay to dodge. Nobody pays to leave.

Nothing has ever been removed from orbit, and only one operator has ever been fined. Both sides here are true at once.

What you already pay
Everyone up there pays to dodge everyone else's junk.
Every avoidance burn costs fuel, which means less working life. The space station has moved 39 times since 1998. One broadband fleet moved more than 300,000 times in 2025 alone.
What nobody owes
Nobody is bound to stop making the junk.
In December 2022 the United Nations asked states to stop destructive anti-satellite tests. The vote was 155 for and 9 against. China and Russia were two of those 9. India abstained, neither for nor against, and the resolution binds nobody.

In plain terms Two sides of a contradiction set side by side so you can weigh the competing claims directly.Source · UN General Assembly resolution record, with Secure World Foundation

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Sources

12 cited.

Every number above traces to one of these. Primary sources first.

  1. 01 Space Environment Report 2025 esa.int European Space Agency · Space Debris Office · primary
  2. 02 Jonathan's Space Report · Starlink Statistics planet4589.org Jonathan McDowell · Harvard-Smithsonian Center for Astrophysics · primary
  3. 03 Collision Frequency of Artificial Satellites: The Creation of a Debris Belt agupubs.onlinelibrary.wiley.com Kessler & Cour-Palais · Journal of Geophysical Research 83(A6), 1978 · primary
  4. 04 Mitigation of Orbital Debris in the New Space Age (Order & Second Report, FCC 22-74) docs.fcc.gov US Federal Communications Commission · primary
  5. 05 UNGA Resolution A/RES/77/41 · Destructive Direct-Ascent ASAT Missile Tests press.un.org United Nations General Assembly · First Committee · primary
  6. 06 Chinese rocket stage breaks up into cloud of more than 700 pieces of space debris spacenews.com SpaceNews · Andrew Jones · secondary
  7. 07 Analysis of the Cosmos 1408 Breakup leolabs-space.medium.com LeoLabs · analysis
  8. 08 Press Release: Break-up of Russian-owned space object (RESURS-P1) spacecom.mil US Space Command · primary
  9. 09 Astroscale's ADRAS-J Mission Completes Operations, Begins Deorbit astroscale.com Astroscale · primary
  10. 10 Station Maneuvers to Avoid Orbital Debris (April 30, 2025) nasa.gov NASA · Space Station blog · primary
  11. 11 Direct-Ascent ASAT Tests: State Positions on the Moratorium swfound.org Secure World Foundation · analysis
  12. 12 Fengyun-1C ASAT Test (2007) — long-term debris environment orbitalradar.com Orbital Radar · derived from NASA ODPO Orbital Debris Quarterly News · secondary
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