The CRASH Clock is ticking as satellite congestion in low Earth orbit worsens
- Reference: 1765549723
- News link: https://www.theregister.co.uk/2025/12/12/crash_clock_orbit_collision/
- Source link:
The [1]CRASH (Collision Realization And Significant Harm) Clock is a proposed Key Environmental Indicator (KEI) to give an estimate of how long it would take before a catastrophic collision occurs if collision avoidance maneuvers cease or there is a loss of situation awareness.
The clock is currently 2.8 days, which doesn't sound too bad until you consider that in 2018, before the mega-constellation launches got underway (yes, Starlink, we're looking at you), the CRASH Clock was 121 days.
[2]
Professor Sam Lawler explained the origin of the acronym in a [3]post on Mastodon: "We needed a metric. I originally wanted to do something like 'Kessler Countdown' or 'Kessler Clock' but this isn't a countdown to Kessler Syndrome, it's just showing how bad things are in orbit, and how quickly they could get worse. So, our name for this metric is... Collision Realization And Significant Harm: the CRASH Clock!"
[4]
[5]
Kessler Syndrome is a theoretical scenario where collisions in orbit result in an exponentially increasing amount of debris, effectively rendering some orbital regions unusable. As Lawler noted, the CRASH Clock is more about highlighting how crowded orbit is becoming and how quickly it could get worse in the event of something like a major solar storm or a software issue knocking out collision avoidance systems.
While the CRASH Clock is concerning, if collision avoidance systems continue to perform flawlessly (and any software engineer will know all about coding perfection), there should be no immediate problem.
[6]
However, the increasing number of satellites in certain orbital regions is ramping up the pressure. In July, SpaceX submitted a [7]report to the US Federal Communications Commission (FCC) detailing how many propulsive maneuvers its Starlink satellites had to make over the course of a year. For Generation 1 satellites, the average was 37 per year. Generation 2 satellites averaged 44 maneuvers per satellite per year.
The authors of the CRASH Clock paper broke this down to one collision avoidance maneuver every 1.8 minutes across the entire constellation.
In its report to the FCC, SpaceX noted that it "now nominally uses an even more conservative maneuver threshold approximately two orders of magnitude more sensitive than the industry standard." According to the company, Starlink satellites will take evasive action when the probability of collision exceeds 3 in 10 million, while the industry standard is 1 in 10,000.
[8]
Lawler [9]posted : "One of the scariest parts of this project was learning more about Starlink's orbital operations.
"I had always assumed they had some kind of clever configuration of the satellites in the orbital shell that minimized conjunctions, and we would see the number of conjunctions grow over time in our simulations. But no! It's just random!
[10]DARPA making low-hanging satellites that use air to move
[11]Uncle Sam explores satellites that can create propellant out of thin air
[12]Starlink is burning up one or two satellites a day in Earth's atmosphere
[13]Project Kuiper becomes Amazon Leo as satellite network trickles into orbit
"There's no magic here, it's just avoiding collisions by moving a Starlink satellite every 2 minutes. This is bad."
Regardless of how one feels about the proliferation of satellites in orbit, the CRASH Clock is a sobering statistic of how quickly things could go wrong if collision avoidance systems fail. The report concludes with a call to action regarding how humans utilize low Earth orbit:
"In addition to the dangerously high collision risks calculated here, we are already experiencing disruption of astronomy, pollution in the upper atmosphere from increasingly frequent satellite ablation, and increased ground casualty risks.
"By these safety and pollution metrics, it is clear we have already placed substantial stress on LEO, and changes to our approach are required immediately." ®
Get our [14]Tech Resources
[1] https://outerspaceinstitute.ca/crashclock/
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aTxKJjnNocGx8l5NdhdMsQAAAM0&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://mastodon.social/@sundogplanets/115701377939133993
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aTxKJjnNocGx8l5NdhdMsQAAAM0&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aTxKJjnNocGx8l5NdhdMsQAAAM0&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aTxKJjnNocGx8l5NdhdMsQAAAM0&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://www.scribd.com/document/883045105/SpaceX-Gen1-Gen2-Semi-Annual-Report-7-1-25
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aTxKJjnNocGx8l5NdhdMsQAAAM0&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[9] https://mastodon.social/@sundogplanets/115701447682658918
[10] https://www.theregister.com/2025/11/19/darpas_vleo_satellite_program_advances/
[11] https://www.theregister.com/2024/02/29/satellite_air_propulsion/
[12] https://www.theregister.com/2025/10/06/starlink_vaporizes_satellites_daily/
[13] https://www.theregister.com/2025/11/14/project_kuiper_amazon_leo/
[14] https://whitepapers.theregister.com/
Yay, something else for the deniers to cling to.
Well, you know, government regulation is the only thing that can ever save us. Because of course, a company like SpaceX has no other incentive to prevent it from happening other than government ordering it to do so. They're so greedy, they don't actually care about crashes possibly destroying their entire business model. Nope, must have more regulations.
Crash!
" an estimate of how long it would take before a catastrophic collision occurs"
What counts as "Catastrophic"?
Presumably, two Starlink units taking each other out would qualify, and the world will keep turning. But then again, I guess it's the resulting mess that counts, not the actual loss of the individual hardware/service.
Re: Crash!
Depends on the equivalent to the [1]R Number for viruses.
If a single collision generates NOT enough debris to, on average, cause another satellite to come to pieces then some debris will be generated, but it would not be 'catastrophic'.
However, if a single collision generates MORE than enough debris to start a chain reaction then someone is going to have to figure out how to launch a giant dustpan and brush to clear up the resulting mess!
[1] https://en.wikipedia.org/wiki/Basic_reproduction_number
Back to basics
(Please administer salt before reading as required) It is about time the whole LEO region becomes debris. We need to get back to using our brain to communicate and navigate. Back to basics and manual labour! The added advantage is that the spy satellites will also become extinct in due time. The LEO ones will go first and the MEO and GEO will run out of fuel and cannot be replenished because traversing LEO would instantly kill your precious new satellite.
And, FWIW, all weather and climate satellites will also happily fail soon enough. No more confirmation that we are doomed. Now we really can get going without facts telling we are doing it wrong. And, the occasionally missed stormy rain? Well, we do need rain and a little wet never hurt anybody anyway. But you can't have my towel because I'm hiking a lift to α Centauri.
Starlink Collision Avoidance
Probably has aspects based on collision avoidance algorithm on Tesla vehicles
Re: Starlink Collision Avoidance
Tesla's collision avoidance algorithm looks to be something along the line of I'm a heavy vehicle with quite limited knowledge of my environment and somewhat flaky software. You might want to stay out of my way . Something of the sort -- vehicle with the least to lose in a collision has the right of way -- actually works (sort of) in Boston. But it's had to see how to translate that to the dynamics of Low Earth Orbit.
Straight face or tongue in cheek?
>> any software engineer will know all about coding perfection
Not a week goes by where we don't read about some major bug or insecurity being discovered. One would hope that the devs doing satellite work are better, but are there any meaningful guarantees that they are?
Maybe they have a dream team assembled from SolarWinds, LastPass, and Cisco.
None of the conclusions are justified but pearl
clutching is always fun for someone!