[HN Gopher] The Kessler Syndrome: Space junk in orbit
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The Kessler Syndrome: Space junk in orbit
Author : RageoftheRobots
Score : 57 points
Date : 2021-11-21 21:09 UTC (1 hours ago)
(HTM) web link (onezero.medium.com)
(TXT) w3m dump (onezero.medium.com)
| natch wrote:
| Isn't part of the beauty of low earth orbit the fact that it is
| less susceptible to this, as free flying debris in LEO tends to
| encounter drag and get caught by the atmosphere? Because of this
| I'm not sure recent and upcoming LEO satellite deployments really
| factor into Kessler Syndrome that much, despite how numerous they
| will be.
|
| So, it seems a bit disingenuous for the article to make a big
| deal of LEO satellites.
| pdonis wrote:
| Unfortuately, "low Earth orbit" is a broad term. The article
| gives a range from 99 miles (about 160 km) to 1200 miles (about
| 2000 km). Orbits at the low end of that range will encounter
| significant atmospheric drag and will indead tend to clean
| themselves up over time (as another poster has pointed out
| upthread). But orbits at the higher end of that range will not.
| That's the problem.
| sscept wrote:
| The article doesn't make any effort to explain the orbital
| mechanics and ultimate dynamics of a Kessler Syndrome.
|
| The assumption I think you're making is all debris remains in a
| fairly localized decaying orbit, which is not the case when a
| high energy collision occurs. The debris will fan out in two
| radial smearing patterns that loop back around at the collision
| point. Some pieces will hit more atmo for longer periods while
| others will achieve higher altitudes for a time and those can
| debris fields last longer. Should a LEO cascading collision
| event happen we would see lots of debris fields reaching higher
| orbits and a non-zero risk of those satellites being hit too.
| DantesKite wrote:
| It's a problem, but I don't think it's that intractable of a
| problem, since any company launching products into space has an
| incentive not to have them destroyed by a ring of planetary
| trash.
|
| Cool essay by the way. Learned something new.
| JKCalhoun wrote:
| I'm ignorant of the problem, but since it was compared to
| "rings of trash" (you know, like Saturn, but trashier) might it
| eventually solve itself? I expect the debris would pulverize
| itself and all sort of fall in lock-step until it was just so
| much dust we had to pass through?
|
| Perhaps that would take thousands of years....
| danparsonson wrote:
| I'll just leave this here:
| https://en.wikipedia.org/wiki/Tragedy_of_the_commons
| wongarsu wrote:
| We usually solve the tragedy of the commons situations by
| adding a regulating authority. One could argue that that's
| one of the main reasons for having governments. Of course we
| don't have a world government to appeal to here and the
| number of nations with launch capabilities is rapidly
| growing. But as private organizations lose profit from
| worsening Kessler Syndrome they will push for a solution,
| since this a everyone-looses situation, not winner-takes-all.
| I would predict we wind up with another UN organization,
| similar to the ITU.
| DantesKite wrote:
| I don't think that applies in this context, since any space
| debris will damage space ventures, cutting into profits.
| some1else wrote:
| The private sector might disregard long term risk for short
| term profit, as they did countless times with the environment.
| This was mentioned in the article.
| DantesKite wrote:
| I think they will too. There won't be any incentive in the
| short-term to do anything about it. I just don't think it's
| an intractable problem (as in, impossible to solve over the
| span of a century).
| the_flinstoned wrote:
| The author addressed that exact point explicitly near the end
| of the article; you may want to reread.
| tqi wrote:
| Isn't that addressed in the last 3 paragraphs of the article -
| that companies are incentivized to be too short sighted to
| care?
|
| Or are you saying you think companies will invent/build more
| resilient satellites in response to junk? I am not an expert
| but I wonder how feasible that would be given the weight
| constraints and extreme speeds involved.
| adt2bt wrote:
| I'd love to see an international orbit allocation similar to how
| the fcc regulates spectrum.
|
| Also with the cost of sending a satellite to space about to
| potentially plummet (starship?), wouldn't it just make sense to
| make a lot of cheap satellites that you throw up in a low enough
| orbit that a collision would only require a few years til the
| shattered pieces de orbit and burn up? We may be on the cusp of a
| revolution on satellite technology as the engineering work going
| into each individual satellite drops precipitously and the
| turnaround time becomes weeks not years. I could see a similar
| Cambrian explosion in satellite tech from cheap space access
| similar to when we went from mainframes to pcs. Thoughts?
| aardvark179 wrote:
| Geosynchronous orbits are allocated to countries by the ITU,
| and other orbits are checked via national space agencies. The
| problem isn't quite as simple as dividing up frequency usage,
| but there is an established framework for holding companies and
| nations liable if they do stupid things.
| melony wrote:
| _> there is an established framework for holding companies
| and nations liable if they do stupid things._
|
| International space law, like most other international
| regulations, is only for the small fries. Any country capable
| of inserting into geosynchronous orbit with a domestic
| manufactured launch vehicle is usually also nuclear armed,
| hold a permanent seat on the Security Council or allied with
| a holder, and is immune to most low level sanctions. No real
| space power can be truly bound by treaty if things heat up
| because they are usually the enforcers.
| wongarsu wrote:
| > wouldn't it just make sense to make a lot of cheap satellites
| that you throw up in a low enough orbit that a collision would
| only require a few years til the shattered pieces de orbit and
| burn up?
|
| That's essentially Starlink, though for other reasons. But
| lower orbits see much less of the earth. Earth has a radius of
| about 6000km, at a low-earth orbit of around 600km you are way
| too close to have a good view, so you need a lot of satellites
| to cover the globe. There are also useful special orbits like
| geostationary orbits (where the satellite is always in the same
| spot relative to earth's surface) or sun-synchronous orbit (the
| shadows always look the same because you are in the same spot
| relative to the sun) that are much higher up.
|
| However with cheaper satellites, cleaning up dead satellites or
| larger chunks of debris also becomes cheaper, we just need to
| figure out who has to pay for it. Right now we are kind of
| stuck with everyone being affected but no one feeling
| responsible.
| giantg2 wrote:
| So where's the "ecological" part? There is no ecology to wreck.
| There are concerns about the metallic dust from burning up on
| reentry, but no mention of it in this article.
| Kye wrote:
| Merriam-Webster on ecology: "a branch of science concerned with
| the interrelationship of organisms and their environments"
|
| Humans are organisms. Humans go to space, and will go there
| more with it getting cheaper. Orbital space is an environment.
| Debris collisions are an ecological concern for spacefaring
| organisms.
| sscept wrote:
| Sentinel-6, GRACE-FO, ICESat-2 are among only a few of the many
| numerous LEO observational satellites that are at risk should a
| Kessler syndrome occur... our ability to watch and build
| predictive models of what's going on with our ecology can/will
| be lost; this is a huge added problem to the ongoing global
| ecological collapses and affects our ability to mitigate
| climate change
|
| Not to mention all the communications systems we have in orbit
| that we rely on for our economy which would result in
| significant loss of logistics / economic efficiencies and
| straining growing social political issues. All of which means
| higher likelihood of damage to local and regional ecologies
| kunstmord wrote:
| Steve Wozniak's startup that has been working on mapping the
| stuff that's out there in orbit: https://www.space.com/amp/steve-
| wozniak-privateer-hundreds-s...
| blendergeek wrote:
| Non-amp version: https://www.space.com/steve-wozniak-privateer-
| hundreds-satel...
| YossarianFrPrez wrote:
| > History would suggest we'll screw this up. Space is a commons,
| and we humans have a terrible track record of despoiling commons.
|
| The question isn't "Will there eventually be some sort of
| incentive to clean up space junk?" (which would lead to some sort
| of free-market amelioration if not solution), it's "Can this be
| prevented?" Free market solutions to cleaning up commons often
| come too late and are imperfect.
|
| The one saving grace here is that other living things won't be
| harmed; so there will potentially be less ripple effects.
| pdonis wrote:
| _> Free market solutions to cleaning up commons often come too
| late and are imperfect._
|
| In this case, the commons, if Kessler's predictions are
| correct, will become unusable much more quickly than has been
| the case with other commons in the past. That creates a much
| stronger free market incentive to clean the commons up.
| modeless wrote:
| The solution for this problem is relatively simple. Satellites
| should be put in very low orbits. A satellite collision in high
| orbit is practically irreversible and will pollute space
| essentially forever. A satellite collision in low orbit is
| automatically cleaned up by the atmosphere, over a period of
| years to months to days depending on the orbit height.
|
| In the past it was not practical to put satellites in low orbit
| for several reasons. One, because the same atmospheric drag that
| cleans up debris would pull the satellites out of orbit too,
| severely limiting their useful life. Two, because a satellite in
| low orbit can only see a small part of the Earth's surface at
| once and passes over it very quickly. You can't use stationary
| satellite dishes to communicate with such satellites, and
| establishing continuous coverage over any part of the Earth's
| surface would require hundreds or thousands of satellites.
|
| Two things have happened that changed the game. One, phased array
| antennas are now cheap enough for consumer applications and they
| are able to communicate with multiple fast-moving satellites at
| once without physically pointing at them. Two, SpaceX has
| decreased launch costs to the point where it is now feasible to
| launch thousands of cheap satellites instead of dozens of
| expensive satellites, and replace them all within a few years
| instead of expecting them to last for decades. Starlink
| satellites orbit at 550km where debris lasts only a few years
| before automatically being cleaned up by the atmosphere. Future
| generations may orbit even lower where debris is cleaned up even
| quicker.
|
| The non-SpaceX proposals for large constellations mostly chose
| higher orbits. I think it's time to prohibit this. Starlink
| competitor OneWeb just had a satellite failure at 1200km and that
| dead satellite will pollute orbit for centuries if it is not
| retrieved (and there is no realistic plan to do so, nor proper
| incentives to ensure that it happens). Heaven forbid that it
| collide with something and produce a debris cloud that can never
| be fully cleaned up in our lifetimes. Meanwhile, Starlink has had
| tens of failed satellites and they are all deorbited already or
| well on their way.
|
| It just doesn't make sense to do things the "old space" way with
| a small number of expensive high orbit satellites. Low orbit
| cheap satellites are the future.
| tejtm wrote:
| I agree with all you are saying but hope one point can be made
| more clear and that is;
|
| "Heaven forbid that it collide with something and produce a
| debris cloud that can never be fully cleaned up in our
| lifetimes."
|
| At that altitude the time for natural orbital decay is not
| within our lifetimes by tens of thousands of years. If mammoths
| and saber tooth tigers littered up there it would still be a
| hazard to us today.
| gooseus wrote:
| I'd be interested in seeing a deep dive analysis comparing the
| costs in energy / environmental impact, as well as risk
| profiles from space debris of maintaining clouds of lower-earth
| orbit satellite vs constellations of higher-earth orbit
| satellites.
|
| For the lower orbits I think there are some points to be made
| about the additional flights to maintain enough satellites, as
| well as the questions of what happens to all this junk as it
| de-orbits? If we're talking about sustainable infrastructure,
| what kind of new weird material/chemical build-ups are we going
| to be dealing with after 50 years of tens/hundreds of thousands
| of private satellites partially burning up and partially
| raining down on random spots on the planet?
|
| Perhaps this is less of an issue than I'm imagining it will be,
| but I tend to think we'd be better off figuring out some kind
| of autonomous robot LEO satellite aggregation/recapture
| solution for cleaning up satellites from higher stable orbits
| that can operate farther and live longer. We should be
| allocating our launches to other projects.
|
| Even without considering the emissions of launches, there is a
| significant resource energy/cost for each one and the noise
| pollution also takes a toll on surrounding ecosystem. If we're
| going to be ramping up launches to scale the mass to orbit,
| we're also going to be scaling those negative externalities. I
| think we really need to make sure the mass we're taking up is
| worth it and not just governed by whoever happens to have the
| most money to burn.
|
| I can imagine the very near future where people are paying to
| launch crypto-mining satellites for memes, or some other such
| wasteful nonsense.
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