[HN Gopher] The world must cooperate to avoid colliding satellit...
       ___________________________________________________________________
        
       The world must cooperate to avoid colliding satellites and space
       debris
        
       Author : divbzero
       Score  : 244 points
       Date   : 2021-08-19 08:21 UTC (14 hours ago)
        
 (HTM) web link (www.nature.com)
 (TXT) w3m dump (www.nature.com)
        
       | nix23 wrote:
       | >hundreds of e-mail alerts arrive each day warning of potential
       | space smash-ups
       | 
       | Oh, so they could trow the Fax-machines out? Well done!
       | 
       | Is Email not a bit unreliable for for such a topic?
        
       | bawana wrote:
       | Why is everyone worried about all that junk? It's reaction mass
       | for getting out of orbit or getting back to earth. It's mostly
       | aluminum which melts easy. Just build a solar furnace in space
       | that has a big 'catcher'. Make aluminum ingots. And shoot them
       | off a spaceship which has a giant electromagnet. As you know,
       | pulsing the electromagnet creates eddy current in the aluminum.
       | This force has been used to weld metal
       | 
       | https://www.tandfonline.com/doi/abs/10.1080/0950711980945202...
       | 
       | The ingots fly back to earth and burn up in the atmosphere.
        
         | munk-a wrote:
         | I think the issue is that actually collecting all those bits
         | (if we needed to quickly clean up our orbits) would be
         | extremely expensive. You'll need to adjust delta-v hundreds of
         | times to match orbit and collect all these bits and pieces.
         | 
         | Basically - imagine dusting your place - except you're doing it
         | in a car and you need to stop precisely over each dust mote to
         | collect it. You're going to waste a whole lot of effort on
         | manuvering and what to do with the junk once you've got it is
         | actually a relatively simple problem[1].
         | 
         | 1. You probably want to consolidate all the little bits of junk
         | into one big bit of junk that, at some point in the future, you
         | can scrap for orbital construction.
        
       | flerchin wrote:
       | Kessler syndrome is a real thing, but this reads like FUD.
        
       | cletus wrote:
       | Here's what I've learned: there is zero chance of the world
       | uniting behind any cause. The solution to any of these problems
       | will be economic and out of necessity and never because of
       | altruism.
       | 
       | Want to reduce fossil fuel usage? It'll only happen when cleaner
       | alternatives are cheaper.
       | 
       | Climate change? Nothing will change here until there's an
       | economic reason for carbon sequestration.
       | 
       | This may seem depressing but there's an important lesson here:
       | any sense of urgency is almost always overblown. Things really do
       | have a way of resolving themselves.
       | 
       | Oh and as for space debris, yes it's a problem but space is also
       | really big. Like the US also put a bunch of copper up in space
       | [1] that's still there.
       | 
       | How could this resolve itself? It'll end up resolving itself when
       | launch costs are sufficiently cheap. We've made a ton of progress
       | in the last few decades. IIRC SpaceX cost of getting payloads
       | into LEO is like 20x cheaper than 20 years ago but it's still
       | north of $1000/kg.
       | 
       | But what does the situation look like when the cost gets below
       | $10/kg? That's not as unrealistic as you may think. A lot of
       | attention is given to space elevators. I think these are likely
       | infeasible (eg they rely on discovering a sufficiently strong
       | material that doesn't exist yet).
       | 
       | But orbital rings [2]? These require no magical material and
       | would be completely game-changing. If you have something like
       | that just hang things off them to pick up passing space debris.
       | 
       | [1]: https://www.wired.com/2013/08/project-west-ford/
       | 
       | [2]: https://www.youtube.com/watch?v=LMbI6sk-62E
        
         | IshKebab wrote:
         | > Here's what I've learned: there is zero chance of the world
         | uniting behind any cause.
         | 
         | What about CFCs?
         | 
         | > It'll only happen when cleaner alternatives are cheaper.
         | 
         | Seems like there's a pretty strong economic incentive for spare
         | faring countries not to ruin space.
        
         | celticninja wrote:
         | Except the pandemic shows us that we can. It's not perfect but
         | it was at least a good effort in terms of global cooperation.
         | Bar a few outliers.
        
           | cletus wrote:
           | Here's an alternative view: we may never reach herd immunity
           | with Covid-19 and it may be something we just always have to
           | deal with in large part because a significant percentage of
           | the population won't get vaccinated because of side effects
           | that, if they exist at all, are less than 1 in 1,000,000
           | likely to cause problems.
           | 
           | A large number of people have shown they're quite willing to
           | let millions of people die rather than do something that's
           | less risky than taking a bath.
        
         | Workaccount2 wrote:
         | >any sense of urgency is almost always overblown. Things really
         | do have a way of resolving themselves.
         | 
         | This is just another way of saying "Nobody does anything until
         | there are bodies on the ground"
         | 
         | The point is to at least attempt to resolve the issue before
         | there are any bodies on the ground. And often at the very least
         | those efforts mitigate the number of bodies that do end up on
         | the ground.
        
         | kar5pt wrote:
         | We already have economic reasons for all these things. Not
         | having natural disasters and rising sea levels is an economic
         | benefit. The problem is we don't have a _system_ that captures
         | those benefits in a way that incentivizes actors to work
         | towards them. The reason people don't care is because we have
         | an economic system that incentivizes them not to care. There's
         | nothing natural or unchangeable about this, we're just choosing
         | not to do anything.
        
         | AndrewKemendo wrote:
         | Fully agree with this. In previous years cooperative agreements
         | happened via small opaque groups of people across the world who
         | had a fairly strong hand in driving alignment. Of course this
         | meant that it wasn't so democratic and so people have been
         | pushing against these types of "small group" deals made in back
         | rooms by powerful people.
         | 
         | That has changed such that people do not trust these groups to
         | make these deals on their behalf because there have been bad
         | outcomes. Now there are many more players in the conversation
         | with their own perspectives which, while good for increasing
         | diversity of opinion, also make the system mostly grind to a
         | halt, which allows for groups who want to exploit their
         | perspective to have more time to gain ground.
        
         | mc32 wrote:
         | This seems a bit exaggerated. We have maritime law, telephony
         | agreements, bern convention, international aviation regulations
         | that were developed over time as the need became critical.
         | 
         | I suspect similar will happen as space matures from frontier to
         | settled.
        
           | JohnWhigham wrote:
           | All those things were seeded in different eras. The world is
           | different today. Look at something like the Internet.
           | Completely unregulated, and in the span of a decade has torn
           | societies apart and undone many cultural norms because of
           | rampant tech conglomerates doing whatever they want. And
           | there's virtually no will at all to do anything about it. The
           | best the US can do is inept boomer Congressmen yelling at
           | Zuckerberg why FaceBook doesn't work on their phones.
        
             | mc32 wrote:
             | We'll see. The internet is or was different. It was passing
             | bits around the globe. Making it into a turnpike would have
             | stymied development.
             | 
             | Fragmentation seems to be emerging with some locales
             | wanting or needing more local control of content. That will
             | likely increase with the success of the GFC and its
             | implementation in ex-USSR satellites as well as in Russia
             | itself.
        
           | cletus wrote:
           | I think maritime law and safety is a good example of my
           | point: the path to maritime law is paved in centuries of
           | blood.
           | 
           | And here's the kicker: this didn't even require global
           | collective action. This required governments to police a
           | narrow industry. That's so much easier and yet even then it
           | took centuries.
        
         | typest wrote:
         | This is overly cynical. I agree that in general cooperation is
         | very hard, and if things can be solved by a private entity,
         | that is a good strategy. But the world has united behind causes
         | before. A good example is the hole in the ozone layer. The
         | world identified CFCs as causing this problem, and united
         | behind the Montreal protocol. Now, the hole is shrinking and is
         | expected to be closed by mid century [1].
         | 
         | I emphasize this because international cooperation is important
         | to solve many problems. Let's not misrepresent the situation
         | and pretend it's impossible. It has happened before, and we
         | would do well to make sure it continues to happen.
         | 
         | [1]https://www.epa.gov/ozone-layer-protection/international-
         | tre...
        
           | barbazoo wrote:
           | I bet there wasn't a refrigerator lobby back then
           | manipulating public opinion and lining politician's pockets
           | like it is with oil, gas, etc.
        
       | BurningFrog wrote:
       | One science fiction thought is that inducing Kessler Syndrome on
       | Earth would be a perfect way for a Moon or Mars colony to
       | "declare independence".
       | 
       | If Earthlings can't get off the planet, it doesn't matter how
       | much money, people and power they have.
        
       | [deleted]
        
       | dalbasal wrote:
       | If I was writing a science fiction... space debris is a wonderful
       | way of imprisoning a planet. Just put a bunch of junk in orbit,
       | now no one can get out. Only a Han Solo type with asteroid
       | avoiding skillz and a taste for danger.
       | 
       | Maybe a built-in step in the intergalactic civilisation process
       | is launching a bunch of satellites, letting them crash, and
       | forming an orbiting wall. This gives baby civilisations a few
       | millennia to grow into their newfound power as the space debris
       | forms into rings, allowing launches again.
        
         | lttlrck wrote:
         | There's a great sequence in Wall-E when he leaves Earth and
         | breaks through the debris field. Not as you imagined but cool
         | nonetheless.
         | 
         | https://youtu.be/RmG5tUCrrsA&t=60
        
         | MauranKilom wrote:
         | Space junk, like everything else in orbit, moves at speeds
         | measured in kilometers per second. There is no asteroid weaving
         | that lets you dodge a pea-sized steel fragment approaching you
         | at 16 kilometers _per second_.
        
           | dalbasal wrote:
           | You obviously have met my friend Han.
        
           | thanatos519 wrote:
           | But I heard Han Solo made the Kessler Run in 12 picoparsecs!
        
             | MauranKilom wrote:
             | > 12 picoparsecs
             | 
             | That's... a length. About 230 miles or 370 kilometers to be
             | exact. ;)
        
         | jawilson2 wrote:
         | This is the plot of part of the Timothy Zahn Admiral Thrawn
         | Books (Last Command). He cloaks something like 30 small
         | asteroids and puts them in orbit around a rebel planet, but
         | makes it appear like he might have released 100's. No one can
         | enter or leave the planet until they are cleared, and they have
         | no idea how many there are.
        
           | uCantCauseUCant wrote:
           | There is another book fallen dragon, were the descendants of
           | a californian colony, "lock up the sky". Santa Chico is the
           | name of the planet.
           | https://en.wikipedia.org/wiki/Fallen_Dragon
        
           | PeterisP wrote:
           | Obviously people _can_ enter or leave the planet as long as
           | they 're willing to take a risk of dying equal to [space
           | covered by 100s random orbits] / [total surface of planet],
           | which is nonzero but small. If you're launching straight up,
           | thousands of such asteroids would leave you with 99% chance
           | of success - the trouble is that with modern standards we
           | generally don't consider 99% good enough - e.g. for space
           | shuttle, 2 out of 135 crashed, getting almost 99%, and that's
           | considered not ok; but if you really _need_ to (as opposed to
           | launches just for PR and science) then you can definitely get
           | out of planet 90%+ of the time.
        
       | thedudeabides5 wrote:
       | Seems inevitably we'll eventually get unsustainable levels of
       | junk up there.
       | 
       | Anyone have creative ideas for how to clean all this crap up
       | someday with "deep tech"?
        
       | emtel wrote:
       | A sanguine take from Casey Handmer of the JPL:
       | https://caseyhandmer.wordpress.com/2019/10/25/space-debris-p...
        
         | detritus wrote:
         | Fascinating, thank you! The graded tungsten particulate cloud
         | idea is particularly clever.
        
       | AndrewKemendo wrote:
       | At this point I don't have much faith that there is any
       | existential scenario that would unite the world in cooperation.
       | 
       | The fact that this isn't existential or even comprehensible to
       | lets say 80% of the world's population, tells me we as engineers
       | and designers need to plan for our technologies to be able to
       | operate despite an inevitable cascading space collision.
        
       | rob74 wrote:
       | When I read "avoid a catastrophic space collision", I thought
       | about an asteroid hitting the earth and endangering life itself.
       | Compared to that, a "catastrophic collision that knocks out one
       | or more satellites key to their safety, economic well-being or
       | both" sounds rather like an inconvenience. Of course, it could be
       | "catastrophic" too, but there is catastrophe, and then there is
       | catastrophe...
        
         | bluGill wrote:
         | We can't grow enough food to support our population without
         | GPS, so either this leads to mass starvation or we go back to
         | 98% of the population becoming subsistence farmers. I'd guess
         | the former - not enough people will be willing to work that
         | hard until it is too late - we are out of food in the middle of
         | winter and thus won't get more for a few months. (it would be
         | possible to force some people to starve in early winter thus
         | saving enough food for the rest)
        
           | kwhitefoot wrote:
           | > We can't grow enough food to support our population without
           | GPS
           | 
           | Can you justify this?
           | 
           | Edit: I mean can you provide an authoritative source or a
           | plausible argument for believing this?
        
           | davidhyde wrote:
           | Maybe you're right. As the general population uses less and
           | less of their creative brains at some point they will be
           | incapable of coming up with an alternative to gps (today
           | someone would most likely have the cognitive capability to
           | erect positioning beacons on their farm).
        
             | bluGill wrote:
             | It isn't just making an alternative, it is rolling it out
             | as well.
        
           | [deleted]
        
         | zz865 wrote:
         | And add to that "The world must cooperate..." you know it'll
         | never happen.
        
           | YinglingLight wrote:
           | There is so much military hardware up there, military
           | hardware disguised as civilian, satellites that were launched
           | successfully but publicly described as a failure/"useless
           | orbit".
           | 
           | The article is essentially asking that all countries need to
           | share the location of their nuclear subs because the Ocean is
           | getting crowded.
        
           | zabatuvajdka wrote:
           | Taking a step further, any nation could deliberately send a
           | weaponized fleet to destroy satellites and then follow up
           | with a ground strike.
        
             | Qem wrote:
             | Kessler syndrome itself could probably be weaponized as the
             | cheapest superweapon ever. Say you rule over a small
             | country, under risk of invasion by a much more powerful
             | country, that relies heavily on GPS guided missiles,
             | aircraft and ammunition. Probably it would not be very
             | expensive to pick a couple fat satellites at the right
             | orbital plane, blow them with small missiles able to reach
             | orbital altitude, and let the resulting debris scattershot
             | start a chain reaction to take down every GPS satellite in
             | existence, rendering low to medium Earth orbit useless for
             | centuries as a byproduct. Those smart ammunitions would be
             | crippled overnight, forcing the more powerful country to
             | risk old style boots-in-the-ground invasion, with much
             | degraded technical support.
        
               | lutorm wrote:
               | Antisat weapons aren't exactly simple, either, though.
               | It's only been successfully done a few times.
               | Intercepting something at orbital velocity isn't trivial
               | (unless you have the capability to actually launch
               | something into a similar orbit and effect a gradual
               | orbital rendezvous.)
        
           | JohnJamesRambo wrote:
           | If only there was some sort of United Nation organization
           | that wasn't constantly undermined and turned into theater...
        
         | the-dude wrote:
         | That doesn't sell.
        
         | ceilingcorner wrote:
         | Adjective inflation. Yet another consequence of the advertising
         | business model.
        
           | dalbasal wrote:
           | "the advertising business model" or the modern world more
           | broadly?
           | 
           | One way or another, there's a lot of short attention span
           | razzle dazzle these days. Maybe adjective inflation is just
           | positively correlated with the volume of media or even of
           | people trying to talk to each other.
           | 
           | It's hard competing with impending asteroid collision.
        
             | ceilingcorner wrote:
             | I follow many people online because I care what they have
             | to say. Because I have read their works before and find
             | their ideas insightful.
             | 
             | Not because they write clickbait headlines.
        
               | relativ575 wrote:
               | How did you know about those to follow in the first
               | place?
               | 
               | They are known because 1) they care to publish their
               | opinion, and 2) they tell others about their work.
               | 
               | 2) is also known as marketing, a.k.a. advertising. We're
               | often told it isn't enough to do good work to advance our
               | career, we have to tell others about it as well. How well
               | you present your story has big impact on how far reached
               | and well received your work can be.
               | 
               | Bottom line is, you are influenced by
               | marketing/advertising, whether you want to admit it or
               | not. You following someone is for sure not solely because
               | of the quality of their work.
        
           | dontreact wrote:
           | Let's say this business model were banned or didn't exist.
           | Getting people to choose to read your articles instead of the
           | billions of other things they could be doing with their time
           | on the internet would still be critical if you want to get
           | them to subscribe.
           | 
           | I think it's less to do with the business model of
           | advertising but rather I think both that business model and
           | the tendency towards inflating adjectives are both caused by
           | there simply being too much information, entertainment etc.
           | for us to make a reasonable decision of what to pay attention
           | to. We've exceeded our own human capacities to process and
           | choose between different streams of information.
        
             | dalbasal wrote:
             | Agreed. Social media's the prime example. Take Youtube's
             | monetization. Creators are plugged into a payment per view
             | world. That's definitely an aggravating factor, but the
             | competition for attention is there in a similar form with
             | or without the ad model.
        
             | mistermann wrote:
             | I think another cause that we do not notice or just take
             | for granted is the way our language itself is designed, it
             | almost seems deliberately designed to support imprecision,
             | ambiguity, confusion, etc. without it being obvious the
             | speaker had that intent.
        
             | ceilingcorner wrote:
             | That might be true, but I think if a business doesn't rely
             | on views/advertising to fund itself, it has more room for
             | creating a quality brand and attracting subscribers that
             | way. As opposed to writing clickbait headlines.
             | 
             | This is essentially what the Financial Times does.
        
         | FiberBundle wrote:
         | As far as I understand this actually would be a catastrophe.
         | One collision creates a lot of debris, which then again
         | increases the probability of further collisions and so on. You
         | have an exponentially increasing probability of further
         | collisions once you have one. In the worst case this could make
         | rocket launches and satellites in orbit impossible.
        
           | thih9 wrote:
           | I think what GP meant is that this kind of catastrophe (i.e.
           | worst case not being able to make rocket launches or use the
           | orbit) is still better than an asteroid crashing into the
           | earth and perhaps causing an extinction event.
        
             | nautilius wrote:
             | Sure, anything is less catastrophic than an extinction
             | event. Where's your threshold? Tsunami in Indonesia?
             | Tsunami in Fukushima? Hurricane Katrina? Do those count as
             | catastrophes?
             | 
             | The problem isn't that we're no longer able to launch new
             | rockets - it's that anything in space comes to a standstill
             | when it gets destroyed. How about GPS is suddenly no longer
             | usable, with planes in flight and ships somewhere on the
             | ocean? Weather satellites allow no more observation, with
             | no more forewarning for hurricanes, and no reliable
             | planning of routes by either plane or ship. What will be
             | the impact of both on modern agriculture? No more satellite
             | based communication, etc.
        
               | thih9 wrote:
               | > Where's your threshold?
               | 
               | I meant world scale extinction event like
               | https://en.m.wikipedia.org/wiki/Cretaceous-
               | Paleogene_extinct... . A layer of sediment literally
               | everywhere, etc.
        
               | mschuster91 wrote:
               | We will find fallbacks. Humanity as a species is
               | surprisingly resilient.
               | 
               | > How about GPS is suddenly no longer usable, with planes
               | in flight and ships somewhere on the ocean?
               | 
               | Anything over land can be replaced by antennas sending
               | out a signal from a known location, and receivers can
               | triangulate their position from that. In-flight planes
               | can use landmark plus compass based navigation, as well
               | as (already existing) ground based navigation beacons,
               | and pilots are trained on how to deal with all
               | instruments gone dark scenarios. Ships can sail along
               | land and use sextant navigation on the open seas
               | (actually, the US Navy re-introduced training sailors in
               | sextant use in 2016, to account for a no-electronics
               | scenario!).
               | 
               | > Weather satellites allow no more observation, with no
               | more forewarning for hurricanes, and no reliable planning
               | of routes by either plane or ship.
               | 
               | The worst loss will be for everything over the open sea,
               | but land based weather documentation will still be
               | possible.
               | 
               | > What will be the impact of both on modern agriculture?
               | 
               | Not too much, technically we can gather everything
               | agriculture needs from the ground, it's just way more
               | effective and cheaper to observe from space.
               | 
               | > No more satellite based communication, etc.
               | 
               | That would not be a big loss, there exist (long forgotten
               | outside of amateur radio) technologies to deal with that.
        
               | macintux wrote:
               | You're correct that all of these are addressable in
               | isolation, given time, with some loss of utility.
               | 
               | However, if we experience a catastrophic problem in
               | space, we'll have to deal with all of them
               | simultaneously, with extreme time pressures.
        
               | mschuster91 wrote:
               | The scenarios where losing GPS would cause immediate
               | issues (naval and air transport) have built in that
               | possibility in their training for ages.
        
           | headmelted wrote:
           | For anyone that didn't know, this is essentially the premise
           | of the movie Gravity.
        
             | mLuby wrote:
             | Gravity strikes a good balance between realism and getting
             | the point across to orbital-mechanics-unsavvy audiences.
        
               | thatswrong0 wrote:
               | I mean, it definitely showed how _fast_ and destructive
               | space debris can be. But I wouldn 't say it really
               | achieved a significant amount realism.
        
               | mLuby wrote:
               | and that the debris is a cloud, and that it comes around
               | again (which is very non-intuitive for us--explosions and
               | shrapnel generally don't hit from the same direction more
               | than once)
        
           | arglebarglegar wrote:
           | maybe we need something like this to learn how to be more
           | careful before launching garbage everywhere we go
        
           | [deleted]
        
           | MichaelZuo wrote:
           | https://en.wikipedia.org/wiki/Kessler_syndrome
           | 
           | The degree of exponential growth is still in question but the
           | fact that it will be exponential, and will cause a huge
           | headache eventually if left unchecked is pretty much
           | accepted.
           | 
           | However, enforcement would run into the same problem that
           | enforcing any resource in the international commons runs
           | into, such as overfishing, oceanic/atmospheric pollution,
           | etc.
           | 
           | Since it requires coordinated collective action of every
           | space launching nation, it would require something like the
           | UN security council to really punish nations that defect from
           | the agreed upon program. which opens another can of worms.
        
             | pohl wrote:
             | Your last sentence is depressing. We can't even muster
             | enough e pluribus unum to combat a pandemic within the one
             | nation that holds that motto on its great seal.
        
               | roenxi wrote:
               | There was an unparalleled global knee-jerk and the sort
               | of global coordinated economic reorganisation we've never
               | seen before in the entirety of history. The politics of
               | the situation are still roiling under tensions and
               | stresses that haven't been seen in decades. A vaccine has
               | been rolled out roughly a quarter of the worlds
               | population in 18 months. Vastly more efforts are hurtling
               | through the economic system as humanity reorients its
               | social and technological bearings. Never before has there
               | been such a bleak future for the humble coronavirus.
               | 
               | The situation is neither pro- nor anti- our ability to
               | organise at a mass level. This has been a remarkable 2
               | years to be alive and we've seen a level of urgent
               | response that has never been achieved before, ever. With
               | 3 years to prepare, anything is possible for this Kessler
               | business.
        
               | khuey wrote:
               | Dealing with space debris doesn't require individual
               | action from hundreds of millions of people though. It
               | requires the governments of eleven countries with orbital
               | launch capabilities (counting the ESA as one) to work
               | together.
        
               | [deleted]
        
               | ycombobreaker wrote:
               | 11 Countries? The UN Security Council has five permanent
               | members and they don't always work together (any one of
               | the five can veto resolutions against its own exonomic
               | interest).
        
               | MichaelGroves wrote:
               | The UN Security Council isn't meant to be a politically
               | nimble engine for progressive economic change; it's meant
               | to prevent a shooting war between those major powers.
               | Judging the UNSC by the standard of that design intent
               | and purpose, the UNSC has been quite effective, a few
               | regional proxy wars could have been _much_ worse for
               | everybody on this planet. We can call it a failure if
               | /when America and China start WW3 and cover everybody
               | else in fallout, but that hasn't happened yet. So far,
               | the United Nations Security Council is working well.
        
               | bt1a wrote:
               | I'm not convinced that the latter is any easier than the
               | former.
        
             | Retric wrote:
             | Kessler syndrome is still limited to a range of orbits.
             | Very low earth orbit everything simply de orbits so fast
             | it's not a significant issue.
             | 
             | Geosynchronous orbit is quite packed, but everything is
             | moving in the same direction which prevents the kind of
             | exponential cascade that's so concerning. Above
             | geosynchronous orbit's graveyard stays clear simply because
             | little has the energy to reach that altitude.
        
               | retrac wrote:
               | Yes, it's my understanding that, in practice, Kessler
               | syndrome would most probably mean no geosynchronous
               | satellites. It's slightly reassuring that that isn't as
               | horrifying a proposition as it was thirty years ago.
               | Recent advances would allow things like geonavigation and
               | telecommunications to be supported with Starlink-style
               | low orbit networks, even in that event.
               | 
               | Regarding simply transiting through our ex-satellite
               | rings, I don't think there is consensus. Would it make
               | launches beyond LEO practically impossible, or just
               | theoretically risky in the way that blindly navigating
               | the asteroid belt is? (You _could_ hit something, but it
               | 's so little matter dispersed over so much space it'll
               | probably just be extremely fine dust the shielding can
               | handle. Probably.)
        
               | tgsovlerkhgsel wrote:
               | GEO is only above the equator, i.e. launches beyond it
               | shouldn't be seriously affected if there was a debris
               | belt, unless it reaches a significant density beyond a
               | narrow belt.
        
               | mLuby wrote:
               | To some degree that's true, though collisions will likely
               | create cones of debris that extend significantly above
               | and below the initial orbits, and those shards could
               | smash satellites in those higher or lower orbits, thus
               | continuing the chain reaction.
               | 
               | For example: two satellites collide head-on at an
               | altitude of 300km, creating two debris clouds that extend
               | from 250km to 350km. Each of those catches another
               | satellite, one at 260km and another at 320km, which
               | fragment into debris clouds reaching from 200km to 370km
               | (all numbers made up).
               | 
               | Higher orbits, like geosynchronous, have a lot more space
               | to work with and much slower relative velocities than low
               | Earth orbits.
        
               | Retric wrote:
               | That debris cloud is an abstraction, actual post
               | collision orbits of individual objects are what matters.
               | 
               | At 300km satellites experience significant drag and need
               | regular boosts to maintain orbit. After collision
               | individual objects orbit will almost always include it's
               | altitude at the point of impact and generally expends
               | above and below that point. So while yes the cloud
               | extends to higher orbit, everything would deorbit from
               | your example extremely quickly.
        
             | samstave wrote:
             | Why the fuck do we not have a system to
             | harvest/kill/detonate already deployed satellites??
             | 
             | Thats pretty fucking simple science, is it not?
        
               | ashes-of-sol wrote:
               | It's not.
               | 
               | First, it's not just satellites. There's hundreds of
               | thousands of pieces the size of a marble that'll cause
               | catastrophic damage. And even more smaller pieces, even
               | millimetre long bits of paint have caused damage to
               | vessels.
               | 
               | Second, harvesting (presuming you mean recovery) or just
               | killing (presuming you mean de-orbiting with atmospheric
               | burn up) require expending deltaV. There has been some
               | interesting proposals for using laser ablation or tether
               | based systems, but nothing that I know of that has gone
               | past a paper proposal.
               | 
               | Detonating just adds to the problem.
        
               | samstave wrote:
               | Thanks for the reply... perhaps a good policy would be to
               | not allow any launch off-planet without a recovery /
               | disablement plan?
        
               | vkou wrote:
               | AFAIK, all modern satellites launches require a plan for
               | decommissioning them when they reach EOL.
               | 
               | The problem is 'What happens when the plan fails due to
               | design errors/bugs/accidents/breakages/etc'.
               | 
               | Recovery of a satellite is incredibly expensive.
        
               | samstave wrote:
               | Space Satellite Recovery Startups are back on the menu
               | boys!
               | 
               | We need both space junk recovery and ocean plastic
               | recovery robots.
               | 
               | Recall that startup that tried to launch the ocean
               | plastic/garbage gyre bot and it failed and no mega-corp
               | tried to save them.
               | 
               | if anyone should be forced to help on this effort, it
               | should be amazon/bezos
        
               | ctdonath wrote:
               | Well, ycombinator _is_ a place to change the world by
               | incentivizing profit for doing so. Get some creative
               | actuaries to run the numbers, sell satellite collision
               | insurance, and fund a for-profit orbital janitorial
               | service to improve profit margin on premiums.
        
         | SunlightEdge wrote:
         | That's how I read it too!
        
         | hourislate wrote:
         | According too this article it seems it could very well create
         | some serious issues.
         | 
         | https://www.space.com/space-junk-collision-chinese-satellite...
        
         | everyone wrote:
         | https://en.wikipedia.org/wiki/Kessler_syndrome
        
         | shreddit wrote:
         | "The world" is also a bit of a stretch if you mean a handful of
         | countries
        
       | bolangi wrote:
       | Putting satellites in low orbits will help, since everything in
       | those orbits will eventually decay.
        
       | quadcore wrote:
       | There is a YC startup from a recent batch that want to salvage
       | and solve that.
        
       | nikkinana wrote:
       | No they don't, asshole.
        
       | hunterb123 wrote:
       | > The Californian company SpaceX alone has launched some 1,700
       | satellites over the past 2 years as part of its Starlink network,
       | which provides broadband Internet, with thousands more planned.
       | 
       | None of which are high enough in orbit for this to be an issue.
       | They have a lifespan of 5 years or so before they fall and burn
       | up in the atmosphere. Why was it included in the article? In the
       | first paragraph nonetheless.
       | 
       | None of the other mega constellations are a problem either, they
       | are mega constellations because they are in VLEO. You need more
       | satellites to cover the Earth when they are lower, but they will
       | also all fall back down, posing no long term threat.
       | 
       | Either the author is unaware of what he is writing about, or has
       | malicious intent, either way, it doesn't instill trust in the
       | article if there's no distinction of which type of orbit the
       | satellite is in.
       | 
       | Sure we should be careful with satellites in more fixed
       | positions, but the top paragraph seems like a hit piece against
       | SpaceX, and slightly against the other companies wanting to do
       | satellite constellations (although no name drop)
        
         | z3rgl1ng wrote:
         | Periodic reminder that Starlink's 12k cluster will only support
         | ~500k users[0] at a minimum $1bn cost to taxpayers[1].
         | 
         | [0]
         | https://www.techdirt.com/articles/20200928/09175145397/repor...
         | [1]
         | https://www.google.com/amp/s/www.cnbc.com/amp/2020/12/07/spa...
        
           | deeviant wrote:
           | You must not be familiar with US broadband outcomes. If
           | starlink actually services 500k user for only 1bn it will
           | probably be the best ROI the US has recently gotten in terms
           | of rural broadband access relief funds.
           | 
           | Also your link:
           | 
           | > Starlink currently has 650 satellites in orbit, with 12,000
           | planned by 2026. But even at full capacity the researchers
           | estimate the service won't be able to service any more than
           | 485,000 simultaneous data streams at speeds of 100 Mbps.
           | 
           | These are not even Starlink's official numbers but some
           | estimate by some researchers without any first hand knowledge
           | of Starlink's tech plan. Moreover, it assumes 485,000
           | _simultaneous 100 Mbps_ , a ridiculous standard, no
           | reasonable engineer would define the max user limit of a
           | system to be how many user can use maximum bandwidth
           | simultaneously because that is not how network usage happens
           | in real-world use.
           | 
           | My mother has had at&t dsl in the a rural town, the only
           | broadband provider in the area, it delivers 2 Mbps *at best*
           | aka when it works at all, even if Starlink delivers 20 Mbps
           | with be a massive quality of life improvement.
        
           | hunterb123 wrote:
           | I don't see how your FUD is relevant to this discussion of
           | space debris, please stick to discussing the article.
           | 
           | Please see other reply to you why those articles are FUD,
           | they explained it much better than I could.
        
             | z3rgl1ng wrote:
             | Ah, the relevance is that SpaceX is producing a ton of
             | extra objects in space.
        
       | scarecrowbob wrote:
       | I have a dumb Kessler syndrom question, but I don't really have
       | the physics to answer it myself.
       | 
       | I've been told that worrying about the longer-term implications
       | of systems like Starlink aren't so terrifying because these
       | satellites are in LEO. Specifically, the time for that kind of
       | junk to de-orbit is on the order of 5 years, so the worst case
       | scenario for this junk is to wait it out.
       | 
       | However, if we get a good set of bouncing space junk, how does
       | that affect this? The vectors generated from the parts two
       | colliding small object might be in any direction, including
       | outward?
       | 
       | My physics isn't that great, so I am left with this question:
       | 
       | is it worth thinking about the small bits of junk re-orbiting
       | other junk? Would that push out the timeline of being able to
       | simply wait out a incipient Kessler syndrome?
        
         | TTPrograms wrote:
         | Kerbal Space Program intuition tells me that the worst case is
         | that you produce a high velocity piece of debris aligned
         | perpendicular to radial vector, e.g. aligned with the existing
         | orbit. I think this is a fairly unlikely direction to transfer
         | energy in a head-on collision (by conservation of momentum
         | arguments). That debris would then traverse a fairly elliptical
         | orbit with frequent passes at the same altitude, likely
         | resulting in relatively rapid de-orbit. The main risk would be
         | inducing chain reaction at higher altitudes during those few
         | passes, which seems unlikely.
         | 
         | Any other debris trajectory induced by collision would hit
         | lower altitudes in less than one orbit time (either going
         | outwards and thus on a much more eccentric orbit, resulting in
         | lower altitude pass in less than one orbit time, or going
         | inwards and immediately passing at lower altitudes). So that
         | debris seems likely to deorbit even more quickly, indicating
         | your intuition is correct.
         | 
         | This all makes sense once you grok why craft need two separate
         | boosts to transfer to a higher geocentric orbit.
         | 
         | Of course there's a transition point where satellites are so
         | dense that even these short-lived trajectories are sufficient
         | to induce a self-maintaining chain reaction of debris. I
         | suspect that's unlikely - the probability of a collision
         | occurring in one or two orbital periods seems negligible.
        
         | beecafe wrote:
         | Basically when you modify an orbit with a single impulse -
         | short rocket burn, bumping into something, etc - the resulting
         | orbit will still intersect that point (unless you reach escape
         | velocity). So those pieces should return to that piece of LEO,
         | although they could still be spending large amounts of time far
         | from there.
        
       | protoman3000 wrote:
       | On a global perspective the interests of too many people don't
       | align to reach any sensible consensus by conventional means. We
       | see it with the pandemic, we see it with global warming and we
       | saw it in general with every conflict and wars.
       | 
       | How can we make this happen?
        
         | Lex-2008 wrote:
         | Are you describing what is also known as "Tragedy of the
         | commons"? https://en.wikipedia.org/wiki/Tragedy_of_the_commons
        
           | protoman3000 wrote:
           | The "Tragedy of the commons" is a situation where choices
           | based on self-interest converge to a negative outcome. I
           | would not characterize our situation on global level like
           | that.
           | 
           | The difference is that in our world people do express desire
           | to cooperate, also on a global scale, but reaching consensus
           | seems like an intractable or practically unsolvable problem.
           | Everybody knows that cooperating lies in their own self
           | interest, but what does it effectively mean to cooperate?
           | 
           | It begins at different levels. For example, before we even
           | begin to see disagreement on how to do the the things we
           | want, we already have no consensus on what to do in the first
           | place.
        
             | PeterisP wrote:
             | Arguably it is exactly like the tragedy of commons - the
             | original analogy is common pastures getting overexploited
             | as noone wants to limit their cows so that the pasture
             | isn't overcrowded; and in this analogy noone wants to limit
             | their satellites so that the space isn't overcrowded..
        
               | guerrilla wrote:
               | "A resource arrangement that works in practice can work
               | in theory." - Elinor Ostrom
               | 
               | Good thing that old thought experiment isn't based on
               | empirical evidence from the real world as the first woman
               | to win a Nobel Prize in economics showed us [1]. In both
               | cases, it's in all participants interest as the GP said
               | but there are some further conditions that Ostram
               | outlined. It turns out in the real world, those
               | conditions are met more often than not and can clearly
               | met in this case.
               | 
               | 1. https://en.wikipedia.org/wiki/Elinor_Ostrom#Research
        
           | stackbutterflow wrote:
           | More like the prisoner's dilemma, no?
        
         | dgb23 wrote:
         | Just yesterday I was ranting on hn about how we don't value
         | solving the big problems. But I don't know the answers.
         | 
         | As an individual I try to learn and improve minimizing my
         | negative impact and working towards a sustainable business. But
         | that is so small and insignificant in comparison to solving
         | problems like these.
         | 
         | Maybe we have to think very long term and improve the
         | effectiveness and reach of education. Maybe the hope is that
         | future generations are smarter and more empathetic than us.
        
           | 7952 wrote:
           | Yeah the biggest problem is human cooperation. We will put
           | feet on mars before we ever come close to solving that. And
           | curiously space exploration is something that does seem to be
           | able to inspire people to work together. Lack of cooperation
           | in everything else is why we can't have nice things.
        
           | mistermann wrote:
           | For one, I don't think humanity has developed
           | thinking/communication styles and models that are
           | sophisticated enough to engage in sufficiently cooperative
           | behavior at scale.
           | 
           | For two:
           | 
           | > But I don't know the answers.
           | 
           | Very few people are able to do what you just did: realize
           | that they do not actually know something (see: politics,
           | covid, any culture war topic, etc). This is actually a
           | sophisticated skill, and to say that we do not teach it would
           | be a massive understatement.
           | 
           | > Maybe the hope is that future generations are smarter and
           | more empathetic than us.
           | 
           | My concern is that even if they are much smarter at what we
           | teach, if we're not teaching the skills that are needed
           | (which may not be definitively known yet), we would still
           | fail.
           | 
           | It seems entirely possible to me that humanity is a dead
           | species walking, but we are simply not able to properly and
           | broadly conceptualize that to the degree necessary to wake up
           | and change course.
        
       | h2odragon wrote:
       | Orbits aren't stable.
       | 
       | If they were, worrying about "kessler syndrome" and "we cant
       | pollute space!" would make more sense. But they're not. Stuff put
       | in orbit _will_ fall (or possible escape), and its a real job to
       | find an orbit where that doesn 't happen _quickly_.
       | 
       | Just like "COVID isn't smallpox".
        
         | bayesianbot wrote:
         | Sure, but when two objects collide and transform into 1000
         | objects, a lot more than two of them will find semi-stable
         | orbits. And by semi-stable I mean it doesn't have to be stable
         | as like with satellite, it just have to stay up there for years
         | to be a problem.
        
           | hunterb123 wrote:
           | You'd have to have a lot of energy to knock something from
           | VLEO to GEO.
           | 
           | I don't see it being a possibility, but I could be wrong,
           | maybe someone smarter than me can do the math...
           | 
           | Space is vast, if you have debris with a lifespan of 5 years,
           | you won't accumulate enough for it to be unavoidable, and the
           | issue will literally solve itself.
        
       | deites wrote:
       | Nice post!
        
       | mike_hock wrote:
       | Maybe this is the solution to the Fermi paradox: Advanced
       | civilizations tend to create runaway space debris collisions,
       | preventing them from leaving their home planets.
        
         | hosteur wrote:
         | This is known as the Kessler syndrome. And it is not a good
         | solution to the Fermi paradox by itself. Because it would only
         | require a very small fraction of civilizations to avoid it to
         | spread.
        
           | [deleted]
        
           | FeepingCreature wrote:
           | Also, Kessler syndrome doesn't keep you from leaving the
           | planet, just from having satellites. When passing through a
           | debris shell, as opposed to staying in it for years, the
           | collision risk is very small.
        
             | labster wrote:
             | How deep are those debris shells anyway? If we had a
             | collision cascade in LEO, would geosynchronous orbits be
             | generally safe? They're pretty far apart, but I don't know
             | for sure.
        
               | didgeoridoo wrote:
               | I have no intuition for this, as it is not modeled in KSP
               | :)
               | 
               | I'm trying to imagine a collision cascade that would
               | generate debris with a significantly higher apoapsis than
               | the original satellites... perhaps a head-on collision
               | between prograde and retrograde orbits that ends up
               | "squirting" some debris at extreme velocity in the
               | normal/antinormal direction? Alternately, an object on a
               | highly elliptical orbit (probably already space junk)
               | near its periapsis with max kinetic energy hitting a
               | satellite prograde?
        
           | worldsayshi wrote:
           | Fermi tangent: I wonder if the Fermi paradox is a bit of a
           | fallacy of reverse casualty in a similar vain to asking - how
           | come we end up in the Goldilocks zone around a star? Because
           | sentient life is not likely to appear in other conditions.
           | 
           | Why are there no aliens making contact? Because if there were
           | such aliens it would be a high probability that they wouldn't
           | want to leave earth alone and then humanity wouldn't have a
           | chance to evolve here.
           | 
           | In other words, any surrounding aliens or non-aliens that
           | have left earth alone for enough time for humans to have
           | evolved are unlikely to suddenly want to make contact at any
           | certain point of our development.
        
             | bluGill wrote:
             | The speed of light alone is enough to explain it. Aliens
             | cannot get here, and so they don't know we exist. Even if
             | you believe there is life elsewhere, odds are it is far
             | enough away that they cannot detect us (not to mention
             | radio hasn't make it 150 light year yet - which is a much
             | smaller amount of stars).
        
               | BurningFrog wrote:
               | The universe is 14 billions years old. That plenty of
               | time for a civilization to spread around all the galaxy,
               | at least.
        
               | hunterb123 wrote:
               | To be fair only some of that time is usable as you have
               | to wait for the many conditions of life to happen. That's
               | a lot of coincidences to wait for, then the long
               | evolution process...
        
               | [deleted]
        
         | thanatos519 wrote:
         | I doubt the Great Filter manifests the same way in every case.
         | 
         | We are going to be stuck here for a long time because of
         | climate change, but the quantity of stored carbon from early
         | plants here is probably not common. Other earthlike
         | civilizations might have to switch to solar/wind/wave
         | electrical generation sooner, or they could just listen to
         | their scientists and drown their plutocrats.
         | 
         | We could also nuke ourselves.
         | 
         | Kessler syndrome is hardly our biggest problem.
         | 
         | Life always finds a way ... to take itself out.
        
           | orwin wrote:
           | > might have to switch to solar/wind/wave
           | 
           | You mean our main power generation tools until the 1900s?
        
             | guerrilla wrote:
             | No, solar wasn't one and the other's have radically
             | increased in efficiency and decreased in price.
        
             | Filligree wrote:
             | And it wasn't enough power.
             | 
             | Economic development is largely built on increasing
             | accessible power. We have alternatives to coal and oil
             | _now_ , but back in the 1900s we didn't.
             | 
             | Those are both made from dead trees, which for millions of
             | years simply didn't rot; this simultaneously cooled the
             | planet down, dramatically weakening hurricane patterns for
             | all time until... now, while also storing millions of
             | years' worth of solar power for our use. A lot of otherwise
             | habitable planets very likely didn't go through that phase.
        
           | heavenlyblue wrote:
           | > from early plants here is probably not common
           | 
           | Why not? Seems like this is exactly what would regularly
           | happen to plant-like life.
        
       | minikites wrote:
       | We already can't work together to avoid catastrophic Earth
       | problems like climate change, why would we start cooperating in
       | space?
        
         | stOneskull wrote:
         | planes fly around without crashing into each other. the
         | agencies involved work together there.
        
       | [deleted]
        
       | StreamBright wrote:
       | It is kind of funny how humans cannot exist without putting
       | garbage all around the places they visit.
        
       | ricardobeat wrote:
       | Could we have most things in space orbiting in the same
       | direction? That would massively reduce the risk of collisions as
       | their relative speeds would be lower, including any fragments
       | resulting from a crash.
        
         | Symmetry wrote:
         | That's what we do for geosynchronous orbit, for example. But if
         | you want a satellite to fly over the entire surface of the
         | Earth to take pictures it'll have to be in a polar orbit and
         | those all cross at the poles where the last major collision
         | was.
        
         | marcofiset wrote:
         | How would you cover the whole planet if things can only go in a
         | single direction? Things orbiting around a sphere must cross
         | paths at some point in order to get global coverage.
        
         | mLuby wrote:
         | In general we do, because launching from west to east at the
         | equator lets you use the Earth's rotation for a 465m/s speed
         | boost. Launching the other direction means you need an _extra_
         | 465m /s just to counteract the rotation you started out with.
         | Polar orbits don't gain or lose much from the rotation since
         | they're aimed over the planet's poles.
        
       | [deleted]
        
       | dormento wrote:
       | My layman's understanding makes me wonder if we could solve this
       | situation with a big-ass magnet in orbit, to slowly eat the
       | debris.
       | 
       | OF course there would be complications from the simple fact that
       | it would need to be very big, incredibly durable (as to not
       | generate more debris itself), hard to launch (probably too heavy)
       | and taken into account in all the calculations going forward.
        
         | SonicScrub wrote:
         | Unfortunately it's not that simple. Space is big. You just
         | won't believe how vastly, hugely, mind-bogglingly big it is. I
         | mean, you may think it's a long way down the road to the
         | chemist's, but that's just peanuts to space. And the valuable
         | space in orbit is no exception. Take the entire surface area of
         | the Earth, and then extrude it up into a volume roughly 800km
         | high. That's the volume you need to clear (and that's just Low
         | Earth Orbit). There is no magnet powerful enough to make even a
         | dent.
        
           | gentleman11 wrote:
           | What if it was a billion smaller magnets? Over time they
           | would clump up with other debris and other clumps, and the
           | mass would make the orbits decay faster. This is my very
           | uninformed idea, maybe magnets just have such short range
           | that it's not feasible at all
        
             | SonicScrub wrote:
             | If you put a billion magnets in space haven't you just
             | increased the space-junk problem by multiple orders of
             | magnitude?
             | 
             | Also, heavier objects decay slower than light ones.
             | Atmospheric drag is the driver of orbital decay. If you
             | increase an object's mass, you lower the de-acceleration
             | provided by atmospheric drag. Drag force scales with
             | surface area, which increases as the square of size,
             | whereas mass increases with the cube. Therefore, increase
             | the size, and mass increases at a faster rate than drag
             | force. Therefore in general larger objects decay slower
             | than small ones
        
           | Taylor_OD wrote:
           | Yup. This is one of those issues where in most folks heads
           | near by space/orbit is small in comparison to the vastness of
           | space and the universe. Which it is. However its still
           | incredibly massive and difficult to comprehend just how big
           | it is.
        
           | short_sells_poo wrote:
           | I wholly agree with the spirit of your post, but I thought
           | LEO is not that problematic because there is still
           | atmospheric drag there that will bring down rubbish in the
           | matter of years.
        
             | SonicScrub wrote:
             | Well the clean-up problem get's even more complicated with
             | MEO and beyond as the amount of space becomes even larger.
             | As for space-junk not being a problem in LEO, you are
             | correct that space junk in LEO will de-orbit in a somewhat
             | reasonable time-frame (on the order of a few years), but
             | that's still problematic. It would still cause the
             | destruction of 100s of billions of dollars worth of
             | equipment, the ceasing of any operations dependent on LEO
             | satellite equipment, and either increasing the risk or out-
             | right blocking launches through LEO for a number of years.
             | The fact that this would be temporary does not mean it
             | isn't very bad.
        
       | thangalin wrote:
       | Stars in the Milky Way form a pancake-like disc 120,000 light-
       | years across. In ~80 years our fastest space ships will hurl
       | along around 900,000 kilometres per hour, assuming they can leave
       | orbit. ;-)
       | 
       | That makes 144 million years to travel across the galaxy. Now
       | space-faring peoples probably won't have evolved near the disc's
       | edge. So let's say it takes about 100 million years to fan out
       | and colonize most of the galaxy's habitable planets.
       | 
       | Our one data point on technologically advanced life indicates 4.5
       | billion years for it to find a foothold after the dawn of a new
       | solar system. Depending on the values you put into an E.T.
       | calculator[1], there are between 4 and ~200 advanced alien
       | civilizations loitering about. We know of many Sun-like stars
       | that are ten billion years old in the Milky Way, twice as ancient
       | as our star.
       | 
       | One hundred million years barely registers on either a 5.5 or a
       | 10 billion year scale. That scale affords aliens an enormous
       | amount of time to have sown their seeds. Hence Fermi's Paradox
       | and hence why a Kessler Cascade setback would be a footnote's
       | footnote on these timescales. In short, a Kessler Cascade is
       | important to avoid, but doesn't resolve Fermi's Paradox (it isn't
       | a Great Filter).
       | 
       | [1]: https://www.omnicalculator.com/physics/alien-civilization
       | 
       | P.S.
       | 
       | I describe a novel solution for Fermi's Paradox in my hard sci-fi
       | book. Am looking for beta readers; see my profile for contact
       | details.
        
       | mikemoka wrote:
       | an interesting take:
       | 
       | https://www.colorado.edu/today/2020/05/26/solving-space-junk...
        
         | cynusx wrote:
         | That would work and incentivize effective removal of space
         | debris too.
         | 
         | It may even be implemented by consensus as it would generate
         | revenue for the taxman.
        
       | zarkov99 wrote:
       | In the US the first thing we need to figure out is whether the
       | democrats or the republicans are to blame. Then we can decide if
       | we are pro or against space collisions.
        
         | pc86 wrote:
         | The only thing lazier than people trying to hamfist partisan
         | politics into unrelated discussions is people complaining about
         | it before it even happens.
        
       | etothepii wrote:
       | Since space debris doesn't factor into the Insurance Underwriting
       | pricing decisions at all of the space underwriters that I know it
       | seems hard to believe this is a real problem.
        
         | nabla9 wrote:
         | _An actuarial modifier for underwriting OOS satellite
         | insurance: Space debris mitigation_ , January 2021, The Journal
         | of Space Operations & Communicator 18(01)
         | 
         | >Insurers are already pulling out of the market for LEO due to
         | the risks of collision and space debris. General market
         | consensus indicates current premium volume about half of what
         | it should be.
         | 
         | https://www.researchgate.net/publication/348151316_An_actuar...
        
       | peanut_worm wrote:
       | I feel as though there are more clickbait headlines than usual on
       | HN lately
        
       | jnxx wrote:
       | From the article:
       | 
       | > "Collisions are proportional to the square of the number of
       | things in orbit," McDowell told Space.com. "That is to say, if
       | you have 10 times as many satellites, you're going to get 100
       | times as many collisions.
       | 
       | Unfortunately, any collision also increases the number of things
       | in orbit, by breaking up spacecraft. The collision between
       | Kosmos-2251 and Iridium 33 generated 1,300 pieces of debris in
       | orbit. The collision between Object 48078 from Russia's Zenit-2
       | rocket and China's Yunhai 1-02 generated 37 known debris objects,
       | and likely a lot more smaller untracked objects.
       | 
       | This is likely to lead to Kessler Syndrome, a chain reaction of
       | collisions once the density of debris fragments above a certain
       | weight passes a critical density:
       | 
       | http://aquarid.physics.uwo.ca/kessler/Critical%20Density%201...
       | 
       | Unless satellites are brought back to Earth, the likely path of
       | development is that Earth will get a layer of satellite debris
       | which makes a a good part of satellite technology basically
       | infeasible (and any spaceflight much more dangerous).
        
         | PeterisP wrote:
         | All the low earth orbits decay due to low but meaningful
         | resistance from the thin atmosphere; satellites like the SpaceX
         | Starlink essentially are continuously "brough back to Earth"
         | unless they periodically boost themselves up to maintain orbit
         | height.
        
           | tgsovlerkhgsel wrote:
           | How quickly though? Given the size of the constellations that
           | are currently being launched, could all of LEO become an all-
           | destroying debris cloud, forcing us out of LEO for a year or
           | so until it has decayed?
           | 
           | Possibly not a disaster now, but once people start relying on
           | Starlink & co, it could be.
        
             | lutorm wrote:
             | The orbital decay time depends on the ballistic coefficient
             | of the body. This scales as mass/area, so is lower for
             | small objects, meaning they decay faster.
             | 
             | If the decay time for a Starlink satellite is a couple
             | years, fragments from a collision will deorbit much faster.
        
         | didericis wrote:
         | If things got that bad I think there'd be increased incentive
         | to invent something to clean it up. It's a very hard problem,
         | but it doesn't seem impossible to deal with, I think it just
         | requires fairly extreme intervention.
         | 
         | I think most orbits naturally decay, too, so there'd be a time
         | limit even if we couldn't clean things up.
        
           | LeifCarrotson wrote:
           | It sounds like you're shrugging off the problem, ignoring the
           | advice of experts who are suggesting we need to make changes
           | now and deciding instead that you'll ask those same experts
           | to fix the problem later when their predictions come true;
           | allowing intuition, incentives to continue current behavior,
           | and resistance to change to determine your course of action.
           | 
           | But intuitions fail when it comes to how mind-bogglingly big
           | and fast space is. The volume you might need to sift through
           | has an area equal to the surface of the entire planet and a
           | height of thousands of kilometers. The objects you're trying
           | to grab are moving at >20,000 km/hr. Low orbits do decay
           | naturally in a few decades, yes, but MEO and GEO orbits can
           | take thousands to millions of years to decay.
           | 
           | It's like being a war zone where bullets that are fired
           | continue ricocheting through the air for decades, and these
           | objects are moving ten times faster than a typical bullet
           | (and may weigh hundreds of kg). We're laying a minefield and
           | not even keeping track of where the mines are laid. The least
           | we can do is to keep track of and share the satellite orbits.
        
             | didericis wrote:
             | I'm not shrugging off the problem, and people should be
             | extremely wary to the point where I think it makes sense to
             | portray the situation as if we would be locked to earth
             | forever if it got out of hand so cleanup is never
             | necessary.
             | 
             | However I think people underestimate ingenuity and the
             | ability to solve the cleanup problem if we really have to.
             | I don't know how much effort has really be invested in
             | hitting that cleanup problem as hard as possible, as most
             | discussion about it currently is theoretical, and there
             | isn't a lot of financial benefit to researching it.
             | 
             | If it starts preventing launches, then the incentives to
             | hit the problem harder increase.
             | 
             | It'd obviously be better not to be forced into figuring out
             | whether that problem is solvable, my point is it's not set
             | in stone that it's an unsolvable problem, and the
             | incentives are currently such that I don't think we can
             | consider possible solutions adequately explored.
        
             | didericis wrote:
             | I think we're also currently tracking most existing debris
             | fairly comprehensively/that seems to be the part of the
             | problem currently receiving the most attention, and
             | rightfully so. As of right now tracking debris and trying
             | not to create more of it seems like the best way forward
        
             | asdfasgasdgasdg wrote:
             | The probability of a collision in meo, heo, or geo are also
             | much lower than leo, though, because the volume of these
             | spaces are much, much larger. Low Earth orbits end around
             | 2000km up. Meanwhile geo orbits are around 35000km. That
             | means that a sphere drawn at geo altitude has a surface
             | area around 300x as large, and the volume of a 2km space
             | above and below these altitudes is 5000x as large.
             | 
             | Not that it isn't something we should be concerned about,
             | but especially the higher up you go the more that concern
             | should be tempered by the sheer remoteness of the odds of a
             | collision.
        
               | CrazyStat wrote:
               | > That means that a sphere drawn at geo altitude has a
               | surface area around 300x as large, and the volume of a
               | 2km space above and below these altitudes is 5000x as
               | large
               | 
               | The size of a sphere at geostationary orbit altitude is
               | essentially irrelevant, because the only reason you go to
               | geostationary orbit is to be geostationary, i.e. in a
               | narrow band at the equator. The other 99.9% of your
               | sphere is completely unused.
        
               | asdfasgasdgasdg wrote:
               | I suppose, but in that case relative velocities between
               | orbiters should be quite low as well.
        
             | MichaelGroves wrote:
             | > _Low orbits do decay naturally in a few decades, yes, but
             | MEO and GEO orbits can take thousands to millions of years
             | to decay._
             | 
             | Tens of years? Try tens of months. The ISS has a minimum
             | mean altitute of 370 km, a max of 460 km, and within those
             | parameters loses about 2 km per month. But the lower it
             | gets, the faster it falls. When it's on the lower end of
             | it's range, it falls about 3 km per month and that would
             | accelerate rapidly if allowed to go lower. As it is, the
             | ISS is boosted several times a year; five times this year
             | so far: https://www.heavens-above.com/IssHeight.aspx They
             | can go as long as a few months without boosts, but not much
             | longer than that. Not tens of years.
             | 
             | The ISS is big and draggy, but the situation isn't much
             | different for smaller satellites in similar orbits. Two
             | test satellites for Starlink, Tintin A and B, were launched
             | to about 500km in 2018. Both have subsequently burned up in
             | the atmosphere after less than three years:
             | https://www.n2yo.com/satellite/?s=43216
             | 
             | > _It sounds like you 're [...] ignoring the advice of
             | experts_
             | 
             | Heh, forgive me for this but it seems like you have some
             | half-baked ideas about Kessler syndrome you gleaned from
             | popsci media. The reality is not so simple, nor as extreme,
             | as you've made it out to be. Your estimates for LEO are
             | about an order of magnitude off.
        
           | i_haz_rabies wrote:
           | I wonder if there isn't already a team at SpaceX or something
           | working on a few moonshot solutions.
        
             | bell-cot wrote:
             | SpaceX probably has several rough-draft plans for mopping
             | up dangerous orbiting debris sitting in a filing cabinet
             | somewhere.
             | 
             | BUT - So long as SpaceX avoids being seen as "at fault",
             | any Kessler sh*t-storms that occur are likely to prove huge
             | opportunities for SpaceX, and huge problems for all of
             | their competitors. Most debris-storm clean-up ideas require
             | plenty of launches, to get the Wonder Widgets and Space
             | Squeegees into orbit. Likewise the replacements for all the
             | smashed satellites. Which replacements may be substantially
             | heavier, due to beefed-up propulsion systems for debris
             | dodging, armor protection around their vitals, etc.
             | 
             | And guess what company is the world's miles-ahead provider
             | of low-cost orbital launch services, with an easy path to
             | oh-so-profitable scaling up?
        
               | testplzignore wrote:
               | This would be a great plot for a Bond film. I think
               | Daniel Radcliffe would make for an interesting casting
               | choice for Musk.
        
               | bell-cot wrote:
               | Um... Who would be the villain? What's his evil plan? My
               | comment was analogous to "If COVID gets really bad, then
               | Elan's Eatery has more outdoor seating and a better
               | location for curb-side pickup than any other restaurant
               | in town."
               | 
               | (Yes, I know that "Moonraker" was an extremely profitable
               | Bond film. No matter how idiotic the [cough][gag]science
               | in it was, Hugo Drax _was_ trying to wipe out most of
               | humanity.)
        
               | datameta wrote:
               | It's an appealing narrative but Kessler Syndrome is
               | something that would stand in the way of Musk's primary
               | mission of getting us set up on Mars. So even if one
               | holds the belief that he is highly profit motivated
               | beyond the scope of funding his main project, it should
               | be evident that this would divert much needed resources
               | and time that put a hamper on the Mars timeline.
               | 
               | I highly recommend the Starbase tour with Everyday
               | Astronaut, especially Part 3 [0], for perhaps the best
               | existing look into his thought process and development
               | philosophy. Throughout the tour he comes across as
               | humble, ready to incorporate ideas and truly entertain
               | questions from a studied layman. What also really speaks
               | for him is how he is treated by his employees, how he
               | treats them, and how involved he is with the ground level
               | of the operation. It is evident to what deep level of
               | urgency and importance he approaches the undertaking that
               | SpaceX is and so I do not believe they would seek to
               | profit from controlling Kessler Syndrome.
               | 
               | [0] https://youtu.be/9Zlnbs-NBUI
        
       | diego_moita wrote:
       | > The world must cooperate
       | 
       | The world can't cooperate to block spread of covid, to end
       | hunger, to avoid global warming, to end traffic of sex slaves, to
       | curb nuclear weapons, to end chemical weapons and land mines, ...
       | 
       | Heck, even in some "civilized" countries people can't collaborate
       | to achieve mass vaccination...
       | 
       | Do you really have any hope we will collaborate on organizing
       | space traffic?
        
         | krisoft wrote:
         | > Do you really have any hope we will collaborate on organizing
         | space traffic?
         | 
         | Yes. It's a much simpler problem with a lot fewer agents.
         | Furthermore all agents share the same incentives. It is in
         | every satellite operator's best interest to not pulverize their
         | sat by an other one.
        
           | Workaccount2 wrote:
           | I think the concern is that some of those satellite operators
           | might be totally subject to the will of some dumbass dictator
           | or politician.
           | 
           | I think of that Romanian dictator (Ceausescu) who let his
           | totally uneducated wife design the subway system in
           | Bucharest. It was completely non-sensical, but the engineers
           | had their hands tied (although they did secretly build
           | stations in anticipation of common sense coming along at some
           | point.)
        
         | uCantCauseUCant wrote:
         | The world can collaborate on not firing upon each other with
         | nuclear weapons. Our "great" sociopathic leaders - worry
         | greatly - at least for their own asses. Which means,
         | collaboration is possible, its just not desired by all those
         | deranged minds in power.
        
       | perihelions wrote:
       | It was reported this week that there was a catastrophic collision
       | back in March,
       | 
       | https://www.space.com/space-junk-collision-chinese-satellite...
        
       | hoseja wrote:
       | Space is very, very big.
       | 
       | The smaller the space is (lower orbits), the faster any debris
       | decays and burns up.
       | 
       | Whipple shields are a thing.
       | 
       | I really don't see much potential for a catastrophe.
        
         | nix23 wrote:
         | Then this will be of interest for you:
         | 
         | https://en.wikipedia.org/wiki/Kessler_syndrome
        
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