8 ms·

New Calculation Finds we are close to the Kessler Syndrome [video]

119 points by cratermoon 2y ago

visviva 2y ago
The paper in question is here: https://link.springer.com/article/10.1007/s40295-024-00458-3 https://link.springer.com/article/10.1007/s40295-024-00458-3 It adds to a pretty large body of literature around this subject, the gist of which is "risk is going up, but we don't really have a good way of estimating what that means in terms of actual collision rates".
- deleted 2y ago
  [deleted]
m3kw9 2y ago
I would think newer sats will have collision avoidance capabilities and older ones will just crash. Maybe even clean up sats will be developed to collection them
- bell-cot 2y ago
  With currently deployed tech, most of the smaller orbital debris is not (usefully) track-able. At orbital velocities, you gotta know it's coming to be able to avoid it. And a orbital velocities, the untrack-able stuff can still kill a satellite.
- michaelmrose 2y ago
  Leo starts at 7.8 kilometers per second and speed plus secondary and subsequent collisions with very small debris makes it impractical. Also carrying fuel to react frequently would dramatically change the entire mission. If your non refuelable sat is good for 6 months it probably no longer makes sense to launch it.
- bagels 2y ago
  Satellites fail (lost control, or spontaneously explode). Very small debris is everywhere and under 5-10 cm largely untracked, but some are working to fix this gap. There is no incentive large enough for cleanup (it's expensive, nobody can/wants to pay, and there are a lot of objects)
benchmarkist 2y ago
As long as it is militarily and commercially viable then the number of satellites will continue increasing, regardless of what academics have to say about collision rates. As per usual this is a coordination problem and in case people have not noticed nations are becoming less coordinated and more insular.
- akira2501 2y ago
  > in case people have not noticed nations are becoming less coordinated and more insular. And what is your yardstick for measuring this? As far as I can tell this is the opposite of true. It's a popular national news meme but I don't believe it's been measured in any reliable way.
  - bragr 2y ago
    I don't know about whether it is more or less common, but there has been international drama over conjunctions over the last several years https://spacewatch.global/2021/12/spacewatchgl-share-chinese-space-station-and-starlink-conjunctions-a-closer-look/ https://spacewatch.global/2021/12/spacewatchgl-share-chinese...
  - benchmarkist 2y ago
    [flagged]
    - akira2501 2y ago
      > so you can greatly simplify your sentence You didn't need to use "greatly" here because the suggestion you're offering without being asked is not particularly great or meaningful. > I think that would greatly aid in your online communications. I communicate online just fine, thank you, I'm also happy to be an individual and to allow that individuality to be expressed through my communications. Thanks again for the unwelcome and unnecessary advice. Please don't use your time to police other peoples writing. It's rude.
      - 2y ago
mapt 2y ago
The current trajectory is that SpaceX proved the commercial and military viability of an LEO megaconstellation, repeatedly lowering their target altitudes and raising their satellite count because of debris and cell size concerns... And now the rest of the world is trying to catch up in a sort of arms race, and not taking any care about debris concerns. The most tempting orbits are the ones in upper LEO that permit them to launch fewer satellites. SpaceX are going to end up well under 500km (orbital lifespan: a decade) before things are finished, and they switched to very low orbit staging with SEP spiral out to reach final orbit a ways back. China's newest constellation Thousand Sails is at an altitude of 800km (orbital lifespan: thousands of years), with a thousand satellites in the works over the next year or so and 14,000 planned, and they're launching them using chemical upper stages designed to explode into a thousand pieces at the target altitude. This is sufficient for Kessler Syndrome all on its own, without counting interactions with anything else up there. A catastropic debris cascade at 800km percolates down to lower altitudes over time and impacts. We need viable treaties limiting development beyond 400 or 500km and we need them ten years ago. I don't know how to sell the urgency of this predicament. You can have as many satellites as you want, a million uncoordinated bodies, at 400km because direct collision potential scales with (satellite count / orbital lifespan) ^2 . At 1000km, satellites decay so slowly we are already too crowded; we have already overused the space. We are speed-running the end of the space age and we are doing it to save a small number of dollars and to avoid a small amount of diplomacy. This is not something we get a do-over on. There is no practical way to collect ton-scale debris at present, no way to track kilogram-scale debris, no practical way to shield pressure vessels against gram-scale debris, and even milligram-scale debris can hit with the force of a bullet. After collisions start occurring at a rapid clip, the mass of potential impactors quickly forms a long tailed lognormal distribution that denies us space for centuries.
- autoexecbat 2y ago
  > upper stages designed to explode into a thousand pieces at the target altitude By this do you mean at the 800km altitude?
  - mapt 2y ago
Oarch 2y ago
There might be a cool storyline where we have to use enormous ground based lasers to clean up and start again. Could even look a bit like the iconic Gibraltar WW2 search lights photographs.
- jcgrillo 2y ago
  What would zapping a satellite with a laser achieve? I suppose if you get it hot enough to melt everything, without anything flying off, then it would turn into a spherical drop of molten scrap... but then what?
  - ZYbCRq22HbJ2y7 2y ago
    I assume the poster means to change its trajectory.
    - sfink 2y ago
      By adding energy (and momentum)? That seems unlikely to work. I guess you could try to shoot at things headed towards you over the horizon, to slow things down? I was assuming it was to vaporize things to make the re-condensed remnants small and dispersed enough to be less of a problem. Though that seems like a tough problem if you have to stay trained on an orbiting bolt for any length of time, as the atmosphere wobbles your laser around.
      - titzer 2y ago
        Well the targeting angle could be low to the horizon, aiming into oncoming debris, reducing its orbital velocity, so that it deorbits faster. The vertical component of the vector would be minimized. A low angle reduces laser efficiency due to more atmospheric interference, but oblique enough it would work. Nearly all man-made satellites (and space junk) orbit in the direction of Earth's rotation because of launch boost, which makes this easier.
  - aeternum 2y ago
    You ablate part of it on the prograde side to create a small retrograde thrust which will deorbit it. I think the right move is to merge this approach with goo blobs. We launch a large goo blobs or nets into a few strategic geostationary orbits and now you only have to ablate objects so they hit the goo then deorbit the goo once it is full (or just leave it there) as they would be large known orbits.
0xbadc0de5 2y ago
My understanding was always that LEO is much less of a Kessler risk due to atmospheric friction - ie: in the absence of active control and regular correction, LEO objects will gradually de-orbit themselves. It's the the higher geostationary orbits that pose the problem.
- aidenn0 2y ago
  Depends on where in LEO. Explorer I had a perigree of about 350km and lasted for 12 years, though the orbit was highly elliptical. 900km and above is stable for thousands of years and well within the (circular orbit) LEO ceiling of 2000km.
resters 2y ago
Positioning a large, armored satellite in low or mid-Earth orbit significantly enhances its strategic value for both offensive and defensive anti-satellite operations. Such a platform could serve as a pivotal asset in maintaining orbital dominance, offering rapid response capabilities to neutralize threats and protect critical infrastructure. In other words, welcome various "death stars" to keep order against malicious Kessler style attacks, etc.
- to11mtm 2y ago
  That helps nothing on the civilian side. Blowing up a sat will do nothing but raise long term risk. Some sort of platform that can launch 'space drones' to deorbit a dead satellite before it crashes or if something else would happened to cause a collision, that could be useful, but, probably expensive.
- lxgr 2y ago
  What do you assume happens to a "neutralized threat" in terms of space junk?
  - resters 2y ago
    Perhaps it is recycled aboard the large armored satellite or propelled into the Earth's atmosphere so it can burn up.
- bagels 2y ago
  "armored" I don't get the impression that you've looked at the physics of orbits. Everything up there carries tremendous kinetic energy. It would be pretty hard to build something strong enough to take on intentional collisions, let alone large debris. Fun reading: https://www.esa.int/Space_Safety/Space_Debris/Hypervelocity_impacts_and_protecting_spacecraft https://www.esa.int/Space_Safety/Space_Debris/Hypervelocity_... Here's a picture to illustrate: https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2013/04/hypervelocity_impact/12635239-1-eng-GB/Hypervelocity_Impact_pillars.png https://www.esa.int/var/esa/storage/images/esa_multimedia/im...
  - 2y ago
donaldihunter 2y ago
I love Sabine Hossenfelder's videos but the audio effects on the transitions are killing me.
- throwaway314155 2y ago
  They're a little too similar to my phone's built in sounds I suppose. Nothing I can't get over though. What about them is "killing you"?
- a2800276 2y ago
  I wish she would put on a different shirt every once in a while.
JumpCrisscross 2y ago
Paper: https://link.springer.com/article/10.1007/s40295-024-00458-3 https://link.springer.com/article/10.1007/s40295-024-00458-3 Anyone have an open link?
exabrial 2y ago
VLEO/LEO is the safest place to put satellites is it not? They'll eventually deorbit themselves if you do nothing, no? The worst place for space junk is high orbits it would seem like. Earth was wildly visited by an Apollo rocket stage a few years back! That is pretty wild.
jmward01 2y ago
The parallels to global warming appear to be close enough that this could be a good area to study what actually changes behavior on a global scale for a global environmental problem. I suspect this is easier to 'fix' mainly because there are fewer entities involved so not a total parallel, but it still might be informative to see when in the crisis arc action actually starts happening and what messaging impacted that timing.
amai 2y ago
We need a Mega-Maid like in Spaceballs to clean up the mess: https://spaceballs.fandom.com/wiki/Mega_Maid https://spaceballs.fandom.com/wiki/Mega_Maid
- numpad0 2y ago
  lasers. autonomous fan-beam laser sats to vaporize prograde surfaces of debris to lower altitudes.
deleted 2y ago
[deleted]
deleted 2y ago
[deleted]
GoblinSlayer 2y ago
Maybe it's a feature. If you want to build a large spaceship on the orbit you have a problem how to launch all the needed material, but with a lot of garbage already up there, you can just recycle it on spot, everything is already launched.

119 points by cratermoon 2y ago

The paper in question is here: https://link.springer.com/article/10.1007/s40295-024-00458-3 https://link.springer.com/article/10.1007/s40295-024-00458-3 It adds to a pretty large body of literature around this subject, the gist of which is "risk is going up, but we don't really have a good way of estimating what that means in terms of actual collision rates".

deleted 2y ago
[deleted]

m3kw9 2y ago

I would think newer sats will have collision avoidance capabilities and older ones will just crash. Maybe even clean up sats will be developed to collection them

bell-cot 2y ago
With currently deployed tech, most of the smaller orbital debris is not (usefully) track-able. At orbital velocities, you gotta know it's coming to be able to avoid it. And a orbital velocities, the untrack-able stuff can still kill a satellite.
michaelmrose 2y ago
Leo starts at 7.8 kilometers per second and speed plus secondary and subsequent collisions with very small debris makes it impractical. Also carrying fuel to react frequently would dramatically change the entire mission. If your non refuelable sat is good for 6 months it probably no longer makes sense to launch it.
bagels 2y ago
Satellites fail (lost control, or spontaneously explode). Very small debris is everywhere and under 5-10 cm largely untracked, but some are working to fix this gap. There is no incentive large enough for cleanup (it's expensive, nobody can/wants to pay, and there are a lot of objects)

benchmarkist 2y ago

As long as it is militarily and commercially viable then the number of satellites will continue increasing, regardless of what academics have to say about collision rates. As per usual this is a coordination problem and in case people have not noticed nations are becoming less coordinated and more insular.

akira2501 2y ago
> in case people have not noticed nations are becoming less coordinated and more insular. And what is your yardstick for measuring this? As far as I can tell this is the opposite of true. It's a popular national news meme but I don't believe it's been measured in any reliable way.
- bragr 2y ago
  I don't know about whether it is more or less common, but there has been international drama over conjunctions over the last several years https://spacewatch.global/2021/12/spacewatchgl-share-chinese-space-station-and-starlink-conjunctions-a-closer-look/ https://spacewatch.global/2021/12/spacewatchgl-share-chinese...
- benchmarkist 2y ago
  [flagged]
  - akira2501 2y ago
    > so you can greatly simplify your sentence You didn't need to use "greatly" here because the suggestion you're offering without being asked is not particularly great or meaningful. > I think that would greatly aid in your online communications. I communicate online just fine, thank you, I'm also happy to be an individual and to allow that individuality to be expressed through my communications. Thanks again for the unwelcome and unnecessary advice. Please don't use your time to police other peoples writing. It's rude.
    - 2y ago

mapt 2y ago

The current trajectory is that SpaceX proved the commercial and military viability of an LEO megaconstellation, repeatedly lowering their target altitudes and raising their satellite count because of debris and cell size concerns... And now the rest of the world is trying to catch up in a sort of arms race, and not taking any care about debris concerns. The most tempting orbits are the ones in upper LEO that permit them to launch fewer satellites. SpaceX are going to end up well under 500km (orbital lifespan: a decade) before things are finished, and they switched to very low orbit staging with SEP spiral out to reach final orbit a ways back. China's newest constellation Thousand Sails is at an altitude of 800km (orbital lifespan: thousands of years), with a thousand satellites in the works over the next year or so and 14,000 planned, and they're launching them using chemical upper stages designed to explode into a thousand pieces at the target altitude. This is sufficient for Kessler Syndrome all on its own, without counting interactions with anything else up there. A catastropic debris cascade at 800km percolates down to lower altitudes over time and impacts. We need viable treaties limiting development beyond 400 or 500km and we need them ten years ago. I don't know how to sell the urgency of this predicament. You can have as many satellites as you want, a million uncoordinated bodies, at 400km because direct collision potential scales with (satellite count / orbital lifespan) ^2 . At 1000km, satellites decay so slowly we are already too crowded; we have already overused the space. We are speed-running the end of the space age and we are doing it to save a small number of dollars and to avoid a small amount of diplomacy. This is not something we get a do-over on. There is no practical way to collect ton-scale debris at present, no way to track kilogram-scale debris, no practical way to shield pressure vessels against gram-scale debris, and even milligram-scale debris can hit with the force of a bullet. After collisions start occurring at a rapid clip, the mass of potential impactors quickly forms a long tailed lognormal distribution that denies us space for centuries.

autoexecbat 2y ago
> upper stages designed to explode into a thousand pieces at the target altitude By this do you mean at the 800km altitude?
- mapt 2y ago

Oarch 2y ago

There might be a cool storyline where we have to use enormous ground based lasers to clean up and start again. Could even look a bit like the iconic Gibraltar WW2 search lights photographs.

jcgrillo 2y ago
What would zapping a satellite with a laser achieve? I suppose if you get it hot enough to melt everything, without anything flying off, then it would turn into a spherical drop of molten scrap... but then what?
- ZYbCRq22HbJ2y7 2y ago
  I assume the poster means to change its trajectory.
  - sfink 2y ago
    By adding energy (and momentum)? That seems unlikely to work. I guess you could try to shoot at things headed towards you over the horizon, to slow things down? I was assuming it was to vaporize things to make the re-condensed remnants small and dispersed enough to be less of a problem. Though that seems like a tough problem if you have to stay trained on an orbiting bolt for any length of time, as the atmosphere wobbles your laser around.
    - titzer 2y ago
      Well the targeting angle could be low to the horizon, aiming into oncoming debris, reducing its orbital velocity, so that it deorbits faster. The vertical component of the vector would be minimized. A low angle reduces laser efficiency due to more atmospheric interference, but oblique enough it would work. Nearly all man-made satellites (and space junk) orbit in the direction of Earth's rotation because of launch boost, which makes this easier.
- aeternum 2y ago
  You ablate part of it on the prograde side to create a small retrograde thrust which will deorbit it. I think the right move is to merge this approach with goo blobs. We launch a large goo blobs or nets into a few strategic geostationary orbits and now you only have to ablate objects so they hit the goo then deorbit the goo once it is full (or just leave it there) as they would be large known orbits.

0xbadc0de5 2y ago

My understanding was always that LEO is much less of a Kessler risk due to atmospheric friction - ie: in the absence of active control and regular correction, LEO objects will gradually de-orbit themselves. It's the the higher geostationary orbits that pose the problem.

aidenn0 2y ago
Depends on where in LEO. Explorer I had a perigree of about 350km and lasted for 12 years, though the orbit was highly elliptical. 900km and above is stable for thousands of years and well within the (circular orbit) LEO ceiling of 2000km.

resters 2y ago

Positioning a large, armored satellite in low or mid-Earth orbit significantly enhances its strategic value for both offensive and defensive anti-satellite operations. Such a platform could serve as a pivotal asset in maintaining orbital dominance, offering rapid response capabilities to neutralize threats and protect critical infrastructure. In other words, welcome various "death stars" to keep order against malicious Kessler style attacks, etc.

to11mtm 2y ago
That helps nothing on the civilian side. Blowing up a sat will do nothing but raise long term risk. Some sort of platform that can launch 'space drones' to deorbit a dead satellite before it crashes or if something else would happened to cause a collision, that could be useful, but, probably expensive.
lxgr 2y ago
What do you assume happens to a "neutralized threat" in terms of space junk?
- resters 2y ago
  Perhaps it is recycled aboard the large armored satellite or propelled into the Earth's atmosphere so it can burn up.
bagels 2y ago
"armored" I don't get the impression that you've looked at the physics of orbits. Everything up there carries tremendous kinetic energy. It would be pretty hard to build something strong enough to take on intentional collisions, let alone large debris. Fun reading: https://www.esa.int/Space_Safety/Space_Debris/Hypervelocity_impacts_and_protecting_spacecraft https://www.esa.int/Space_Safety/Space_Debris/Hypervelocity_... Here's a picture to illustrate: https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2013/04/hypervelocity_impact/12635239-1-eng-GB/Hypervelocity_Impact_pillars.png https://www.esa.int/var/esa/storage/images/esa_multimedia/im...
- 2y ago

donaldihunter 2y ago

I love Sabine Hossenfelder's videos but the audio effects on the transitions are killing me.

throwaway314155 2y ago
They're a little too similar to my phone's built in sounds I suppose. Nothing I can't get over though. What about them is "killing you"?
a2800276 2y ago
I wish she would put on a different shirt every once in a while.

JumpCrisscross 2y ago

Paper: https://link.springer.com/article/10.1007/s40295-024-00458-3 https://link.springer.com/article/10.1007/s40295-024-00458-3 Anyone have an open link?

exabrial 2y ago

VLEO/LEO is the safest place to put satellites is it not? They'll eventually deorbit themselves if you do nothing, no? The worst place for space junk is high orbits it would seem like. Earth was wildly visited by an Apollo rocket stage a few years back! That is pretty wild.

jmward01 2y ago

The parallels to global warming appear to be close enough that this could be a good area to study what actually changes behavior on a global scale for a global environmental problem. I suspect this is easier to 'fix' mainly because there are fewer entities involved so not a total parallel, but it still might be informative to see when in the crisis arc action actually starts happening and what messaging impacted that timing.

amai 2y ago

We need a Mega-Maid like in Spaceballs to clean up the mess: https://spaceballs.fandom.com/wiki/Mega_Maid https://spaceballs.fandom.com/wiki/Mega_Maid

numpad0 2y ago
lasers. autonomous fan-beam laser sats to vaporize prograde surfaces of debris to lower altitudes.

deleted 2y ago

[deleted]

deleted 2y ago

[deleted]

GoblinSlayer 2y ago

Maybe it's a feature. If you want to build a large spaceship on the orbit you have a problem how to launch all the needed material, but with a lot of garbage already up there, you can just recycle it on spot, everything is already launched.