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https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome I wonder what spacex will be worth when launching satellites is i

https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome I wonder what spacex will be worth when launching satellites is impossible for a couple hundred years.

NetMageSCW 3mo ago
Stop trying to make Kessler syndrome a thing - it was never a thing, it isn’t a thing, it will never be a thing. It is just pearl clutching by those too afraid of modern life. Gravity wasn’t a documentary.
- micromacrofoot 3mo ago
  I mean it might be a thing in 100 years but we're not even close now
  - WillAdams 3mo ago
    Which means that we need to act responsibly and plan ahead now so that it is not a thing 100 years hence.
    - micromacrofoot 3mo ago
      if we knew with certainty a doomsday meteor was heading towards earth 100 years from now we still couldn't plan for it, this is not how our species works
- serf 3mo ago
  a new hot take spotted : newtonian physics isn't a thing. let's see how well the freeways work once we stop cleaning up after the accidents.
  - NetMageSCW 3mo ago
    I see you haven’t read the paper. How long do you think Kessler syndrome is projected to take? How long do you think natural clearing of debris at Starlink’s altitudes is?
  - panick21_ 3mo ago
    Freeways are not 3 dimensional and they don't have an automatic cleanup that cleans up things within a pretty short time. Also area we are talking about is fucking gigantic. Also accidents are going to be very rare as sats deorbit themselves end of live and even if they break and can't move anymore, other sats that can still move can evade them.
- hackeraccount 3mo ago
  Hey! I think I saw you on Ars. Or maybe someone there copied and pasted this?
- bell-cot 3mo ago
  Back in the day, "Kessler syndrome" was a fairly good way to articulate the fears of many scientists - whose delicate one-off "flagship" scientific research satellites had huge costs and lead times, if things started going wrong up there. And overall, today's space powers are much more careful about not making messes in orbit.
zwily 3mo ago
Kessler is much less of a problem at their altitude (480km). Debris has too much drag and would get pulled down too quick to have a sustained Kessler situation. It's possible, but very very unlikely at that altitude.
- dualvariable 3mo ago
  You could still generate a mess for 5-10 years at that altitude. Even if it self-clears you still destroy the constellation and deny access to LEO for years.
  - inemesitaffia 3mo ago
    That's not Kessler syndrome though. Is a cascade
    - dualvariable 3mo ago
      A cascade would be bad enough.
Polizeiposaune 3mo ago
It won't be centuries. starlink satellites are in low orbits and will deorbit in a few years at most if bricked; to stay in orbit, they use ion thrusters to counter drag from the very uppermost reaches of the atmosphere. https://ai-solutions.com/newsroom/why-starlink-is-lowering-satellite-altitudes/ https://ai-solutions.com/newsroom/why-starlink-is-lowering-s...
- titzer 3mo ago
  When satellites smash into each other at high velocity, they explode. Some of that debris will end up in higher orbits and linger.
  - Polizeiposaune 3mo ago
    Some of the debris from a collision may end up in an orbit with a higher apogee, perigee will necessarily still be at or below the altitude of the last collision and will be subject to some of the same low-orbit aerodynamic drag that starlink satellites experience; passes through lower altitudes will apply drag that will first drop the apogee and will then eventually cause the debris to reenter.
  - audunw 3mo ago
    How can it linger in a higher orbit. Maybe some of the debris gets a kick which increases its velocity, but you need two velocity boosts to circularise the orbit, no? So I figure at worst you get an elliptical orbit which will still decay
  - moralestapia 3mo ago
    Nope, if it goes up it will go down even faster. Orbits are about speed. Two things colliding cannot have debris coming out at a faster velocity than either of them.
mlindner 3mo ago
Kessler syndrome relies on two key provisions: 1. Orbiting objects never try to avoid each other. 2. They're in high enough orbits that atmospheric drag is not a significant factor such that debris can last decades or centuries. Starlink fails both as they constantly maneuver and they're in low orbits that are constantly cleaned by the atmosphere. And I'd add that "kessler syndrome" is actually a statistical process, not a rapid sudden cascade of satellites crashing into each other. It takes years to decades for it to actually "happen". It's not something that can be caused by military action either.

https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome I wonder what spacex will be worth when launching satellites is impossible for a couple hundred years.

NetMageSCW 3mo ago

Stop trying to make Kessler syndrome a thing - it was never a thing, it isn’t a thing, it will never be a thing. It is just pearl clutching by those too afraid of modern life. Gravity wasn’t a documentary.

micromacrofoot 3mo ago
I mean it might be a thing in 100 years but we're not even close now
- WillAdams 3mo ago
  Which means that we need to act responsibly and plan ahead now so that it is not a thing 100 years hence.
  - micromacrofoot 3mo ago
    if we knew with certainty a doomsday meteor was heading towards earth 100 years from now we still couldn't plan for it, this is not how our species works
serf 3mo ago
a new hot take spotted : newtonian physics isn't a thing. let's see how well the freeways work once we stop cleaning up after the accidents.
- NetMageSCW 3mo ago
  I see you haven’t read the paper. How long do you think Kessler syndrome is projected to take? How long do you think natural clearing of debris at Starlink’s altitudes is?
- panick21_ 3mo ago
  Freeways are not 3 dimensional and they don't have an automatic cleanup that cleans up things within a pretty short time. Also area we are talking about is fucking gigantic. Also accidents are going to be very rare as sats deorbit themselves end of live and even if they break and can't move anymore, other sats that can still move can evade them.
hackeraccount 3mo ago
Hey! I think I saw you on Ars. Or maybe someone there copied and pasted this?
bell-cot 3mo ago
Back in the day, "Kessler syndrome" was a fairly good way to articulate the fears of many scientists - whose delicate one-off "flagship" scientific research satellites had huge costs and lead times, if things started going wrong up there. And overall, today's space powers are much more careful about not making messes in orbit.

zwily 3mo ago

Kessler is much less of a problem at their altitude (480km). Debris has too much drag and would get pulled down too quick to have a sustained Kessler situation. It's possible, but very very unlikely at that altitude.

dualvariable 3mo ago
You could still generate a mess for 5-10 years at that altitude. Even if it self-clears you still destroy the constellation and deny access to LEO for years.
- inemesitaffia 3mo ago
  That's not Kessler syndrome though. Is a cascade
  - dualvariable 3mo ago
    A cascade would be bad enough.

Polizeiposaune 3mo ago

It won't be centuries. starlink satellites are in low orbits and will deorbit in a few years at most if bricked; to stay in orbit, they use ion thrusters to counter drag from the very uppermost reaches of the atmosphere. https://ai-solutions.com/newsroom/why-starlink-is-lowering-satellite-altitudes/ https://ai-solutions.com/newsroom/why-starlink-is-lowering-s...

titzer 3mo ago
When satellites smash into each other at high velocity, they explode. Some of that debris will end up in higher orbits and linger.
- Polizeiposaune 3mo ago
  Some of the debris from a collision may end up in an orbit with a higher apogee, perigee will necessarily still be at or below the altitude of the last collision and will be subject to some of the same low-orbit aerodynamic drag that starlink satellites experience; passes through lower altitudes will apply drag that will first drop the apogee and will then eventually cause the debris to reenter.
- audunw 3mo ago
  How can it linger in a higher orbit. Maybe some of the debris gets a kick which increases its velocity, but you need two velocity boosts to circularise the orbit, no? So I figure at worst you get an elliptical orbit which will still decay
- moralestapia 3mo ago
  Nope, if it goes up it will go down even faster. Orbits are about speed. Two things colliding cannot have debris coming out at a faster velocity than either of them.

mlindner 3mo ago

Kessler syndrome relies on two key provisions: 1. Orbiting objects never try to avoid each other. 2. They're in high enough orbits that atmospheric drag is not a significant factor such that debris can last decades or centuries. Starlink fails both as they constantly maneuver and they're in low orbits that are constantly cleaned by the atmosphere. And I'd add that "kessler syndrome" is actually a statistical process, not a rapid sudden cascade of satellites crashing into each other. It takes years to decades for it to actually "happen". It's not something that can be caused by military action either.