11 ms·

The sky's gone dark

277 points by andyjohnson0 11y ago

deleted 11y ago
[deleted]
27182818284 11y ago
If you would like to read a highly entertaining science-fiction novel about the stars going out, I couldn't recommend http://www.amazon.com/Spin-Robert-Charles-Wilson/dp/076534825X/ http://www.amazon.com/Spin-Robert-Charles-Wilson/dp/07653482... enough.
- allencoin 11y ago
  That does seem like an entertaining read; thanks for the recommendation.
- fsiefken 11y ago
  Yeah, that was a great read even though it's not quite the same scenario :-)
- aaronbrethorst 11y ago
  Seveneves is a bit more similar to what the article describes. http://www.amazon.com/Seveneves-Novel-Neal-Stephenson/dp/0062334514 http://www.amazon.com/Seveneves-Novel-Neal-Stephenson/dp/006...
  - Pelerin 11y ago
    I definitely started recalling the White Sky scenario when reading this post.
  - monochromatic 11y ago
    And a great book in general.
    - aaronbrethorst 11y ago
      Eh, I thought the last third was a letdown.
      - monochromatic 11y ago
        I agree. I still enjoyed the book though.
  - 27182818284 11y ago
    It probably is. Where Spin connects with the posting is more on what the planet does after the satellites fall and new industries for balloons, etc, form. I was on the fence about whether I should mention that or whether it is revealing.
DarkTree 11y ago
"Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it's traveling at orbital velocity" Just wow.
- 19870213 11y ago
  This is what is assumed to have happened to STS-7 (Challenger, not fatal), check the photo of the impact crater in the window here: https://en.wikipedia.org/wiki/Space_debris https://en.wikipedia.org/wiki/Space_debris
- fsiefken 11y ago
  If you haven't seen the movie Gravity and the imagining of high velocity orbital space debris yet... go see it!
- chrisBob 11y ago
  Low earth orbit is about 8km/sec. That means you could have a collision anywhere in the 0-16km/sec relative velocity range.
- theandrewbailey 11y ago
  XKCD What if: https://what-if.xkcd.com/58/ https://what-if.xkcd.com/58/
  - mrmcd 11y ago
    "This means that if an astronaut on the ISS listens to I'm Gonna Be, in the time between the first beat of the song and the final lines ... they will have traveled just about exactly 1,000 miles." https://www.google.com/webhp?q=1000%20miles%20%2F%208%20km%2Fs https://www.google.com/webhp?q=1000%20miles%20%2F%208%20km%2... WHOA
- Jabbles 11y ago
  Not if it's a cube: Volume = 1e-4 ^ 3 = 1e-12 m^3 Assume density 1kg/l Mass = 1e-9kg Velocity = 8000m/s KE = 0.032J Mass of bullet (https://en.wikipedia.org/wiki/Physics_of_firearms https://en.wikipedia.org/wiki/Physics_of_firearms) A .44 Remington Magnum with a 240-grain (0.016 kg) ...(360m/s) Which has 1036.8J of kinetic energy. So the ratio is actually about 32400 in favor of the bullet. But note that this will change with the cube of the size mentioned, so even though this is exaggerated, a fleck of paint 3mm across would make the quote reasonably accurate.
ble 11y ago
Practically every form of debris removal is also a pretty good anti-satellite weapon. Additionally, a not-too-unreasonable interpretation of current international treaties would lead one to conclude that piece of junk, inoperable satellite X (or a piece of debris that comes off of it) is still owned by country Y, interfering with it is a violation of Y's sovereignty, etc. This is to be contrasted with the seas where there are some kind of established norms about the wreckage of ships, abandoned ships, etc. I kinda want to bone up on the relevant treaties and/or agreements about Earth orbit and other planets.
- maxerickson 11y ago
  It would be really easy to make a treaty covering the debris. The most horrible one would just require multilateral signoff on every removal action, but that would work just fine, every one is OK with clearing it out.
  - venomsnake 11y ago
    > every one is OK with clearing it out. Depends. Denying US access to any tech hurts them more than the armies that don't have such high tech capabilities. On the other side - if you US are mostly unaffected by that (preparations etc) they will be so far ahead that cleaning up the debris will hurt US superiority. So - who will be ok with cleanup in that current moment can vary a lot. To see a lot less serious mess unfolding in real time - Syria. While the end game is clear for all - get rid of ISIS and install strong stable government, everyone is moving to get advantage and increase its bargaining pool.
    - maxerickson 11y ago
      Everyone with space launch capabilities would be fine with it, and they are also the relevant parties when it comes to treaty issues. I don't think Russia and China would want to leave junk up there, I don't think any one else is even questionable.
      - jerf 11y ago
rmc 11y ago
Neal Stephenson's latest novel, Seveneves, starts with essentially this premise, but with debris of the Moon.
- masklinn 11y ago
  The Planetes manga starts with space debris and the risk thereof, but terrorists outright attempting to trigger a Kessler event is a big subplot
  - mfoy_ 11y ago
    There's an anime adaptation that's very well done. It explored the ideas of debris in space and clean-up efforts surrounding it pretty neatly.
    - shpx 11y ago
      Planetes is my favourite anime, though granted I haven't watched many. I'm not sure if the logistics make sense though, I haven't done the math but I would imagine that the amount of fuel needed to change orbits would either be prohibitively expensive or you would spend months before returning to the base station.
    - shostack 11y ago
      I loved the anime. Very much a "slice of life" in the future that was wonderfully art directed.
- Terr_ 11y ago
  Reminds me of the "Cowboy Bebop" universe, in which a large portion of the moon was shattered during an early test of hyperspace-gate technology.
lemevi 11y ago
If you hadn't had enough scary sounding possible future calamities that you as an individual have no control over to worry about, here's another. My anxiety system for these kinds of things broke back when peak oil turned out to not be a thing (well as described). There lots of things to be concerned about where we as individuals can make better choices, such as sustainable living and not contributing to carbon emissions, but stuff like this, while something I'm not going to ignore because it's at the very least interesting, I can't feel anxiety about. I just don't have the capacity to be anxious every minute of my life for everything that could possibly go wrong for us someday in the future.
- ctdonath 11y ago
  Indeed. I've lived long enough to see a whole lot of TEOTWAWKI scenarios panicked about and either were duly mitigated by sensible people or simply failed to instantiate. "Y2K Bug" was an ideal example (chronic programming flaw could have knocked out computer systems worldwide and knocked humanity back to the Middle Ages, but was recognized as a solvable problem and was indeed solved). At some point I looked at my own anxieties and simply decided to not be anxious: do what I could about what I could given resource (time included) constraints, be prepared for eventualities within reason, and otherwise carry on. My biggest recurring concern now is how I'm not anxious. Should something horrible happen, I may be disconcertingly unconcerned - having done what I could in good faith, there is/was nothing else to do but accept reality and move on.
  - coldpie 11y ago
    I agree with you, but I think it is still important to be anxious and raise awareness of these problems. Without the panic, would Y2K have been "recognized as a solvable problem and solved"? We need to continue to raise awareness of these really big potential problems, even if we have confidence that they are solvable.
- clarkmoody 11y ago
  I can't find the source now, but some estimate that removing only a few of the largest boosters on orbit each year would decrease the cascade risk significantly, since those boosters represent a large fraction of the mass. This is a much smaller move than many other avoid-the-end-of-the-world suggestions given throughout the years. Now: better modeling would probably help us determine whether Kessler syndrome will actually happen.
riffraff 11y ago
isn't the likelihood of a cascade very low because of the orbit thing? I.e. object X hits Y, they both spin out of control but most likely they will either go towards earth or go away from it, so they chance of them hitting something else is very limited, it's not like billiard balls that would eventually hit each other.
- Zitrax 11y ago
  I assumed that if object Y hits object X it would result in a huge number of particles from the collision, each with a chance of hitting something else eventually. Even if a single one of those particles hit one of our precious objects in the next 20 years it could be devastating.
  - msandford 11y ago
    But as it gets cheaper to put new satellites up, cleanup gets cheaper too. And if access gets cheap enough I could easily see an international treaty mandating that all satellites have an EOL burnup system installed. When 20kg costs $2mm a lot of people will balk at the idea. When 20kg costs $200k or $20k it's a lot easier to require people to include it. It could even be a bolt-on kind of thing, separately powered and controlled such that it doesn't have to be re-invented for every new satellite. Also with access being cheap enough we could start doing active cleanup, beyond just not making the problem worse. Aerogel is supposed to be great for capturing particles because it's basically frozen air. We could build a space-based aerogel factory and ship silicon ingots up which then get turned into aerogel panels to be used as replenishable armor for the factory. And once you have the factory up you just start making the area that the armor sweeps bigger and bigger. Build out sideways to clear a particular orbit faster, build up or down to clear orbits of various heights. It'd be insanely expensive right now, but if launch costs come down to $100/kg or $10/kg it starts to look reasonable.
- spatulan 11y ago
  In 2007, the Chinese tested an anti satellite missile against a weather satellite. The missile contained no explosives, it relied purely on kinetic energy. The collision released 2,300 pieces of debris that were large enough to be tracked, so about golfball size or larger, and probably many times that number that are too small to track.
chrispeel 11y ago
I was just listening to a show about predictions of the end of the world (http://radiowest.kuer.org/post/latter-day-predictions http://radiowest.kuer.org/post/latter-day-predictions), which seems appropriate. The sky is falling!
- eric_the_read 11y ago
  The problem is that the sky isn't falling! It's just... sitting there.
achr2 11y ago
How does space debris reach a stable enough orbit that it doesn't just fall into the atmosphere and burn up? Also (maybe depending on the first question) wouldn't the chaotic nature of space debris collisions cause less stable orbits?
- DasIch 11y ago
  The debris doesn't have to reach stable orbits. The debris gets created in orbits that are already stable. It's also important to consider that stable in this context doesn't mean that the debris stays up there forever, it's just staying long enough to be a problem.
- clarkmoody 11y ago
  Some orbits are much higher than the atmosphere, so they are stable for a long time.
emilburzo 11y ago
Webcache: http://webcache.googleusercontent.com/search?q=cache%3Awww.antipope.org%2Fcharlie%2Fblog-static%2F2015%2F09%2Fthe-skys-gone-dark.html&oq=cache%3Awww.antipope.org%2Fcharlie%2Fblog-static%2F2015%2F09%2Fthe-skys-gone-dark.html&aqs=chrome..69i57j69i58.871j0j4&sourceid=chrome&es_sm=0&ie=UTF-8 http://webcache.googleusercontent.com/search?q=cache%3Awww.a...
- brickmort 11y ago
  thanks!
shiftpgdn 11y ago
If it got bad couldn't we just send up a big cube of ballistics gel with some rockets and grab everything with that?
- russnewcomer 11y ago
  Not to be flippant, but I don't think that would scale well enough. "Space is big. Really 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, but that's just peanuts to space." Douglas Adams, The Hitchhiker's Guide to the Galaxy
tomek_zemla 11y ago
Basically, once we are done covering Earth in garbage we will make sure we do the same to the sky... How human!
- waqf 11y ago
  Second Law of Thermodynamics, to call that "human" seems like unjustified exceptionalism.
- kpmah 11y ago
  Maybe filling our sky with junk will cancel out global warming? Yay humanity!
maxerickson 11y ago
I feel pretty confident that navigation and communications would stay about the same, at least the social aspects pointed at in the question (different tech would be used, but so what). Weather forecasting isn't all that important, warnings for hurricanes would probably be about the same. So there would be some inconveniences, but nothing huge. The geopolitics is the interesting question. I wonder what sort of imaging capability could be attained by strapping systems to commercial flights and fiddling flight paths to increase coverage. That would require international cooperation, but maybe there's enough political will to make it happen.
- smacktoward 11y ago
  > Weather forecasting isn't all that important Unless you travel, use energy or eat food.
  - maxerickson 11y ago
    For travel, the local radar is more useful than a satellite picture or medium term forecast (where the sat data matters more). For food, forecasting lowers production costs, but it isn't good enough that our agriculture actually hinges on it. I realize my phrasing is blithe, but I simply don't see a lot of deep dependence on weather forecasts, they are used to good advantage, but would not be such a huge loss.
    - dalke 11y ago
      Local radar doesn't give IR, which among other things gives sea information. Quoting from https://en.wikipedia.org/wiki/Weather_satellite#Infrared_spectrum https://en.wikipedia.org/wiki/Weather_satellite#Infrared_spe... : > Infrared satellite imagery can be used effectively for tropical cyclones with a visible eye pattern, using the Dvorak technique, where the difference between the temperature of the warm eye and the surrounding cold cloud tops can be used to determine its intensity (colder cloud tops generally indicate a more intense storm).[10] Infrared pictures depict ocean eddies or vortices and map currents such as the Gulf Stream which are valuable to the shipping industry. Fishermen and farmers are interested in knowing land and water temperatures to protect their crops against frost or increase their catch from the sea. Even El Niño phenomena can be spotted. Local radar doesn't give condition more than about 100 miles off-shore. It becomes more difficult to figure out if there's a front or severe storm coming to land. Consider, for example, a small typhoon somewhere in the Pacific. https://en.wikipedia.org/wiki/Cyclone_Tracy https://en.wikipedia.org/wiki/Cyclone_Tracy was spotted by weather satellite on 20 December but wasn't seen on radar until 22 December. It hit on 25 December. With weather satellites, it's easier to route shipping and flights around a disturbance. Weather satellites are also used to identify new volcanic eruptions and route around their effects (http://www.sciencedaily.com/releases/2014/09/140926091334.htm http://www.sciencedaily.com/releases/2014/09/140926091334.ht...), and detect wind patterns over the ocean. At some point it depends on what "deep dependence" means. It can easily be defined to make what you say be trivially true, and therefore uninteresting.
applecore 11y ago
Do we really believe that science, if faced with the immense challenge of orbiting debris, won't find a way to regain access to orbit? When did we become so pessimistic?
- creshal 11y ago
  Of course we'll find a way. But who will pay for it?
- kohanz 11y ago
  I think the point is that this problem is a lot easier to deal with before it is actually a problem. Reminds me of climate change, in that way.
- nabla9 11y ago
  Economics is usually more important factor than science. Science provides possibilities, economics selects those possibilities that are realized. Instead of building those sci-fi space stations and exploring plants that has been scientific possibility for decades, we have realized and exceeded our sci-fi dreams in computers, internet and mobile phones. If billion people spend $10 per month on something, there is economic incentive to spend billions in technological research.
sneezeplease 11y ago
I cant believe you tech worshiping nerds think satellites are real. Look in to how hot the thermosphere is, theres no way satellites exist. Go try and find any picture of a satellite out in space, its all cgi and paintings.
russnewcomer 11y ago
I'm not read enough to understand exactly how the Kessler Syndrome scenario cstross proposes would interact with GPS, but significantly naval spending by the Superpowers is the big powers is the major effect I can easily see. When you have to protect undersea communication lines for military command and control (assuming the Kessler Syndrome would be a convenient way for hostile nations to launch attacks against other nation's orbital assets), meaning drone warfare becomes untenable outside a direct LOS engagement if undersea lines are not secured. I also think there would be a major issue with weather satellites and prediction, causing a significant investment to be made in weather radar and alternative weather prediction and monitoring strategies.
- creshal 11y ago
  > I'm not read enough to understand exactly how the Kessler Syndrome scenario cstross proposes would interact with GPS GPS needs 24 satellites to function as planned. (It might work with less, but 12 seem to be the minimum under optimal conditions). • If a Kessler cascade happens in the GPS satellites' orbits, it will rapidly disable existing GPS satellites, and deny access to said orbits for new satellites. Replacements could be launched into safe orbits, but this will likely take years, and those orbits will have a faster decay rate and less visibility (so you'd need even more satellites). • A Kessler cascade in LEO will likely deny access to higher orbits, so while existing GPS satellites will continue to function, they cannot be feasibly replaced once their 10-30 years life span is exhausted.
  - marcosdumay 11y ago
    I don't get how a Kessler cascade in LEO would deny access to higher orbits. Can collisions become so common that staying in LEO for a fraction of a day is already dangerous? How many debris are we talking about here?
- Symmetry 11y ago
  GPS is all in MEO rather than LEO. It's a larger volume with less stuff in it so there isn't much chance of getting Keller Syndrome up there.
outworlder 11y ago
We'd have to adapt. Plans to colonize Mars and the like would have to be postponed. Important satellites would have to hug Earth's atmosphere to stay (somewhat) safe. They could look somewhat like this: https://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State_Ocean_Circulation_Explorer https://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State... More fiber optic cabling would be required. Local stations to retransmit information would have to be created (or existing infrastructure, such as cellphone towers, would be retrofitted). And so on. We'd do fine, I guess. But not without an enormous cost.
jcromartie 11y ago
Isn't most of the debris moving in the same direction? I'm imagining that being in orbit is like being on the freeway, where the traffic is all running the same direction. Yes, getting hit by a car going 70 MPH would normally be catastrophic, but two cars bumping into each other around 70 MPH is not always a big deal.
- mark-r 11y ago
  I believe that would be true of geosynchronous satellites, otherwise there would be no benefit to being geosynchronous. Any pieces that break off should alter their orbit enough to be out of the way. Edit: I just got dinged for this comment, if there's a flaw in my reasoning or a study that refutes it please let me know.
- ceejayoz 11y ago
  Enough satellites are in polar/retrograde orbits to be an issue. Explosions from Chinese/US anti-satellite tests and accidental collisions go every which way, as well.
  - Symmetry 11y ago
    The satellite that the US shot down was in a swiftly decaying orbit. That means that the periphrasis for all the debris was at least that far down and with the smaller ballistic coefficient of the debris it's all gone now.
- baq 11y ago
  one degree of inclination difference with otherwise similar orbital elements upon impact translates to about .5%-1% of energy of a head-on/t-bone impact. at orbital velocities this is still mindblowingly devastating. you've basically reduced a 8km/s impact into a 40-80m/s which is in 90-180mph range. result is lots of debris created in both orbital planes as both sats (you're comparing cars, so i assume you want sat-sat impact) are totalled, solar panels shattered, etc. and that's basically the smallest accidental collision in space you can imagine (not counting failed berthings/dockings and the like).
- 11y ago
clarkmoody 11y ago
Researchers at Texas A&M University[1] have been working on this problem with NASA JSC for years. The approach has been to go after the large spent boosters (a few thousand of them), since they contain the most mass of any class of debris objects. Each upper-stage booster has a rocket nozzle that makes a great target for grappling. As other comments have noted, the main issue is actually deciding to spend money bringing down orbital debris. As with many other issues we face, this is another case of kicking the can down the road, and we may not address it until the collision cascade has started :-/ [1] http://lasr.tamu.edu/research/proxops/#Debris_Removal http://lasr.tamu.edu/research/proxops/#Debris_Removal
- __d 11y ago
  Having expended vast amounts of energy to get it up there, it seems a shame to bring it back down again. I'm hoping to see a cleanup driven by a desire to reclaim the constituent metals, etc, without a need to boost them out of the gravity well.
freddref 11y ago
If space debris can be detected and tracked, a fleet of garbage collector/deflector bots could clean the path in front of functioning satellites. Though a giant block of expanding foam might be cheaper.
tylermauthe 11y ago
Future business opportunity: Space Garbage Reclamation. I'm only half-joking here, it would be a net benefit to anyone trying to put things into space by avoiding Kessler Syndrome and the junk itself could be valuable. Once we have space-based fabrication facilities, any materials that are already in space are much more valuable than those same materials on Earth.
- zacharypinter 11y ago
  I believe there's an Anime series around this idea: https://en.wikipedia.org/wiki/Planetes https://en.wikipedia.org/wiki/Planetes
- Shivetya 11y ago
  Space borne or even eventually ground base lasers could sweep the sky
natch 11y ago
The worst collision so far was deliberately caused by the Chinese military. Good job guys, way to show what a great country you are: https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_missile_test https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_mi...
- thu 11y ago
  You should read the parts where it says US has done similar tests and that "In response to US weaponisation of space, the Chinese started a space defense program, including anti-satellite defense." That being said, this is a great example related to the OP (e.g. number and sizes of tracked debris and for how long they remain dangerous).
paulsutter 11y ago
> Postulate a runaway Kessler syndrome kicks off around 2030, at a point when there are thousands of small comsats (and a couple of big space stations), ranging from very low orbits to a couple of thousand kilometers up. Human access to space is completely restricted; any launch at all becomes a game of Russian roulette. Postulate? This article hasn't got a shred of calculation to give any hint when this becomes a problem. Is this a 2030 problem or a 2300 problem? No data.
- freehunter 11y ago
  It's a problem right now because we just don't know. It could happen tomorrow. It could happen in 2300. It's all chance. Like the example given of running across a field while machine guns blaze away. You might cross 100 times and be safe. I try to cross once and I'm gone. All we know is, our odds increase with each item we put in orbit.
  - JoeAltmaier 11y ago
    Its measurable and predictable. A model has to be built is all. Nothing magical or unknowable about it. I agree with the idea that we should, fairly easily, be able to answer questions like "when will this become critical" Further, its not a single happening - its a process modeled by a differential equation including terms for orbital decay, particle distribution over time, solar wind, new launches etc.
- maxerickson 11y ago
  The author is trying to start a conversation about the societal implications, not trying to analyze the Kessler syndrome itself.
valarauca1 11y ago
Couldn't researchers just adopt basic fission calculations to work for this application? I mean its fundamentally the same problem. Large particles being impacted by smaller particles causing them to emit more smaller particles. I tried to work though this yesterday, but I'm not sure how to translate the free-space constant to orbital-scale units.
- marcosdumay 11y ago
  At the very minimum, the elasticity is completely different. Also, in one case particles are hold within a lattice, while on the other they are completely free to move in any direction. And there are orbits to think about, while on the other case the deciding factor is particles leaving the lattice... Well, I don't think calculations would look any alike.
  - valarauca1 11y ago
    From the preservative of satellites (and items ejected from them) in the same orbit, they're motions are fixed to each other. They only appear in motion from a 3rd party observer on the ground, or in a different orbital.
nabla9 11y ago
BRUTE FORCE MODELING OF THE KESSLER SYNDROME, Lawrence Livermore National Laboratory http://www.amostech.com/TechnicalPapers/2012/Orbital_Debris/NIKOLAEV.pdf http://www.amostech.com/TechnicalPapers/2012/Orbital_Debris/... Interesting paper where supercomputer was used to simulate the increase of particles greater than 10 cm in size over 100 years with high temporal resolution. Results for BAU (business and usual) and BAU-d business as usual with decreasing breakup rate don't look so good: "linear growth of the catalog size with time, to ~65,000 objects by year 2100." 100 years from now there will be 50 conjunctions per day and 3 collisions per year.
- nateberkopec 11y ago
  I don't understand - what's the difference between a conjunction and a collision?
  - realquick81 11y ago
    The words are self descriptive: Collision = con + laedere = strike together (two things strike each other) Conjunction = con + iungere = join together (two things become joined to each other)
  - panzagl 11y ago
    Conjuctions are when the objects are within a certain distance (basically a safety margin, usually several kms), a collision is an actual strike.
  - nabla9 11y ago
    Conjunction is close approach between two orbiting objects. Satellites may have to execute collision avoidance maneuvers and burn expensive fuel resources if the predicted trajectory brings debris too close for comfort.
deleted 11y ago
[deleted]
snowwrestler 11y ago
> Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it's traveling at orbital velocity, Relative to an object stationary on the ground, yes. But every satellite is already moving at orbital velocity itself. If two satellites are orbiting in the same direction and one blows up, its pieces will not hit the other with full orbital velocity. > any launch at all becomes a game of Russian roulette. Maybe if the situation gets this bad, then the mitigation actually gets easier: just send up a lot of cheap big rockets on parabolic trajectories to orbital height. They will get hit, all the pieces will fall below orbital velocity, and fall down into the atmosphere. We could even launch cheap parabolic trajectory "blockers" to clear holes in the debris field for launches to higher orbits or escape trajectories.
- titzer 11y ago
  They aren't all moving in the same direction. Have a look: http://earthobservatory.nasa.gov/Features/OrbitsCatalog/ http://earthobservatory.nasa.gov/Features/OrbitsCatalog/
daenz 11y ago
Dumb question, but can't we put some giant blocks of single-piece kevlar-ish material in orbit? I imagine they would have no chance for breaking apart and would just serve as "bullet" catchers for these small pieces of debris.
- ble 11y ago
  Hypervelocity is very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, hypervelocity is velocity so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, even metals behave like fluids under hypervelocity impact. https://en.wikipedia.org/wiki/Hypervelocity https://en.wikipedia.org/wiki/Hypervelocity The orbital velocity needed to maintain a stable low Earth orbit is about 7.8 km/s, but reduces with increased orbital altitude. https://en.wikipedia.org/wiki/Low_Earth_orbit https://en.wikipedia.org/wiki/Low_Earth_orbit
blisterpeanuts 11y ago
Eventually we'll have to use some combination of extreme ship armor (meter-thick plating of expired uranium?) and lasers that detect and zap all particles (that aren't human shaped) within 1 km of the spacecraft.
- aetherson 11y ago
  Boosting the kind of armor into orbit that would be necessary to deal with at least the worse scenarios is unfeasible. If you think that cost-to-orbit is high now...
  - blisterpeanuts 11y ago
    True, and probably we'd have to either mine/manufacture the armor in space, or else develop some less expensive heavy lifting technologies (which is pretty much necessary anyway, if we're going to put up more manned space stations and interplanetary craft).
mark-r 11y ago
If this comes to pass, Google's project Loon won't look so looney. http://www.wired.com/2014/06/google-balloons-year-later/ http://www.wired.com/2014/06/google-balloons-year-later/ Unfortunately I don't think there's any feasible replacement for GPS satellites.
- protomyth 11y ago
  Ground stations can replace GPS. It might not be universal, but it for people inside a country it would work. http://www.popsci.com/technology/article/2011-08/ground-based-analog-gps-could-make-positioning-technology-accurate-inches http://www.popsci.com/technology/article/2011-08/ground-base...
- GeorgeHahn 11y ago
  Perhaps it would be possible to do positioning from balloons that reference ground stations or stars. It would be more expensive than the current systems but cheaper than a fully ground based system.
DanBC 11y ago
NASA has an Orbital Debris website. http://orbitaldebris.jsc.nasa.gov/ http://orbitaldebris.jsc.nasa.gov/ It has some nice photos of some of the impacts that spacecraft have had. --- Reading cstross's post at a tangent: I'm interested in how viable it is for a well funded technological terror group (like Aum Shinrikyo used to be) or "rogue nation" to dump a few tons of sand and grit (or depleted uranium, for the mass) into the correct orbits.
peeters 11y ago
> Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it's traveling at orbital velocity True, but most of the other objects near it are also at or near orbital speed, so what's the kinetic energy when compared to an object it would actually be likely to hit? (The situation in Gravity made no sense to me. The shuttle encounters the debris field every 90 minutes...why was that debris not also orbiting the earth with roughly the same period as the shuttle?) Is the solution a matter of countries agreeing to "lanes" for orbits that differ non-trivially? (e.g. 300-330km is reserved for equatorial orbits, 340-360 km is reserved for polar orbits, 380-400km is reserved for retrograde orbits)
- antognini 11y ago
  I could imagine that the two orbits were inclined relative to each other. If the shuttle is orbiting around the equator and the debris field is orbiting from pole to pole then you would encounter it on every orbit. (Although then you would encounter it twice on each orbit...)
- SideburnsOfDoom 11y ago
  > True, but most of the other objects near it are also at or near orbital speed, so what's the kinetic energy when compared to an object it would actually be likely to hit? If they're moving in opposite directions, then you just double it.
  - goodcanadian 11y ago
    Actually, I think you quadruple it as kinetic energy goes as v^2.
- TorKlingberg 11y ago
  If they orbit in opposite directions, the relative speed is twice the orbital speed. Low earth orbits go in all kinds of directions. In geostationary orbit everything is moving in more or less the same direction and speed.
  - 11y ago
seren 11y ago
On that subject, I recommend to read Spin by Robert Charles Wilson. It is not exactly a Kessler syndrome, but for some reason, one day a kind of dome/membrane encloses the Earth blocking communication with every satellite. (Physical objects can still go through as far as I recall, but since you can't communicate with them, it is not that interesting) This is good sci-fi book who won the Hugo award about the societal impact (with somewhat weaker sequel, but still enjoyable in their own way)
Symmetry 11y ago
Kessler Syndrome is a serious potential problem and it's certainly one people should be worrying about but it's mostly something that's only a problem for LEO where you have lots of things in a relatively small volume going very fast in different directions. Further out in MEO where GPS satellites are there's a much greater volume, fewer satellites, and the satellites aren't moving as fast. There's no way Kessler Syndrome is going to start there. You do have a bunch of Russian satellites that loop in fast and close by the South Pole then go high and slow over the North, letting them spend most of their time being visible from Russia. Debris from from a cascade could kill one of those, which would cause debris that would kill some but not all of the GPS sats. It would be a relatively slow process compared to what would go on in LEO, though. Satellites in GEO won't need to worry about Kessler at all. They're all in equatorial orbits, traveling in the same direction at the same speed. If one explodes its debris will only hit other satellites with the explosion velocity, not orbital velocity. So those should survive Kessler Syndrome fine, though you can't put any new ones there. Also, Kessler Syndrom isn't forever. Satellites in LEO need to boost every once in a while to overcome atmospheric drag. As things get broken up their surface area to volume ratio increases and the fall out of orbit faster. Air density falls of exponentially with height so the lower reaches of orbit will become safe first. The inner reaches of LEO might be clear quickly but I have no idea how long it would be before orbit was totally clear.
- al_biglan 11y ago
  Came here to say the same thing. Will also add: If LEO does get polluted, there are options to put (more expensive) satellites into MEO. At this point, it becomes an economic argument to "clean" or "push upwards"
brianbarker 11y ago
So a drone rocket that hovers around in orbit and shoots down debris sounds like another startup idea.
deleted 11y ago
[deleted]
yourapostasy 11y ago
Stross has rarely-found pragmatism and realism in personally-held and publicly-shared opinions about space colonization for a popular science fiction author. While professionally he writes about a human future where we travel the stars, the TL;DR is personally, he holds that with our current understanding of physics, our meat sack bodies will never colonize space. Explore yes, but mass-exodus-colonization or even plant-seed-colonization-for-independent-colony is a pipe dream; he doesn't see the proof that we are capable of even colonizing the solar system, but leaves an open door to invite in that proof. http://www.antipope.org/charlie/blog-static/2010/08/space-cadets.html http://www.antipope.org/charlie/blog-static/2010/08/space-ca... http://www.antipope.org/charlie/blog-static/2007/06/the_high_frontier_redux.html http://www.antipope.org/charlie/blog-static/2007/06/the_high... So a Kessler Cascade definitely sucks, but it isn't an "OMG, humanity loses its 'birthright to the stars'!" catastrophe because we can't GET to the stars for the foreseeable future, barring a Copernican-grade revolution in physics and accompanying engineering that opens a hitherto-unknown means of multiple magnitudes FTL transportation of the peta- to tetra-tons of mass associated with an en masse out-migration to the stars scenario. This has interesting implications (I happen to strongly agree with his analysis) for how we set and carry out future policy, if you want to figure out means of nudging our species' survival odds upwards over the long haul (Long Now Foundation, millennia to millions of years scale).
Aardwolf 11y ago
I guess all kinds of ways to handle it will appear if it is important enough, saying it will all go dark seems a bit too strong. Shielding. Special shapes to minimize impact. Smart avoidance movements. Continuous automatic cleanup of space debris. Etc...
Apocryphon 11y ago
On the bright side, imagine the orbital competitions that will result between megacorps and billionaires with space hotrods. Kessler Run, anybody?
- soperj 11y ago
  Kessel run?
sergiotapia 11y ago
>There are some proposals to mitigate the risk of Kessler Syndrome by using microsats to recover and deorbit larger bits of debris, and lasers to evaporate smaller particles, but let's ignore these for now: whether or not they work, they don't work unless we start using them before Kessler syndrome kicks in. Lol, ok then let's ignore proposed solutions.
rdsubhas 11y ago
Why not just launch a big magnet into orbit and stick 'em all together? EDIT: serious question
SZJX 11y ago
I don't think the human beings will have no solution in hand for such a critical situation. Clearing up the debris to a good enough extent such that we can launch things normally won't be that hard at all, when hundreds of billions of dollars are at disposal. I'm not worried about this one.

277 points by andyjohnson0 11y ago

deleted 11y ago

[deleted]

If you would like to read a highly entertaining science-fiction novel about the stars going out, I couldn't recommend http://www.amazon.com/Spin-Robert-Charles-Wilson/dp/076534825X/ http://www.amazon.com/Spin-Robert-Charles-Wilson/dp/07653482... enough.

allencoin 11y ago
That does seem like an entertaining read; thanks for the recommendation.
fsiefken 11y ago
Yeah, that was a great read even though it's not quite the same scenario :-)
aaronbrethorst 11y ago
Seveneves is a bit more similar to what the article describes. http://www.amazon.com/Seveneves-Novel-Neal-Stephenson/dp/0062334514 http://www.amazon.com/Seveneves-Novel-Neal-Stephenson/dp/006...
- Pelerin 11y ago
  I definitely started recalling the White Sky scenario when reading this post.
- monochromatic 11y ago
  And a great book in general.
  - aaronbrethorst 11y ago
    Eh, I thought the last third was a letdown.
    - monochromatic 11y ago
      I agree. I still enjoyed the book though.
- 27182818284 11y ago
  It probably is. Where Spin connects with the posting is more on what the planet does after the satellites fall and new industries for balloons, etc, form. I was on the fence about whether I should mention that or whether it is revealing.

DarkTree 11y ago

"Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it's traveling at orbital velocity" Just wow.

19870213 11y ago
This is what is assumed to have happened to STS-7 (Challenger, not fatal), check the photo of the impact crater in the window here: https://en.wikipedia.org/wiki/Space_debris https://en.wikipedia.org/wiki/Space_debris
fsiefken 11y ago
If you haven't seen the movie Gravity and the imagining of high velocity orbital space debris yet... go see it!
chrisBob 11y ago
Low earth orbit is about 8km/sec. That means you could have a collision anywhere in the 0-16km/sec relative velocity range.
theandrewbailey 11y ago
XKCD What if: https://what-if.xkcd.com/58/ https://what-if.xkcd.com/58/
- mrmcd 11y ago
  "This means that if an astronaut on the ISS listens to I'm Gonna Be, in the time between the first beat of the song and the final lines ... they will have traveled just about exactly 1,000 miles." https://www.google.com/webhp?q=1000%20miles%20%2F%208%20km%2Fs https://www.google.com/webhp?q=1000%20miles%20%2F%208%20km%2... WHOA
Jabbles 11y ago
Not if it's a cube: Volume = 1e-4 ^ 3 = 1e-12 m^3 Assume density 1kg/l Mass = 1e-9kg Velocity = 8000m/s KE = 0.032J Mass of bullet (https://en.wikipedia.org/wiki/Physics_of_firearms https://en.wikipedia.org/wiki/Physics_of_firearms) A .44 Remington Magnum with a 240-grain (0.016 kg) ...(360m/s) Which has 1036.8J of kinetic energy. So the ratio is actually about 32400 in favor of the bullet. But note that this will change with the cube of the size mentioned, so even though this is exaggerated, a fleck of paint 3mm across would make the quote reasonably accurate.

ble 11y ago

Practically every form of debris removal is also a pretty good anti-satellite weapon. Additionally, a not-too-unreasonable interpretation of current international treaties would lead one to conclude that piece of junk, inoperable satellite X (or a piece of debris that comes off of it) is still owned by country Y, interfering with it is a violation of Y's sovereignty, etc. This is to be contrasted with the seas where there are some kind of established norms about the wreckage of ships, abandoned ships, etc. I kinda want to bone up on the relevant treaties and/or agreements about Earth orbit and other planets.

maxerickson 11y ago
It would be really easy to make a treaty covering the debris. The most horrible one would just require multilateral signoff on every removal action, but that would work just fine, every one is OK with clearing it out.
- venomsnake 11y ago
  > every one is OK with clearing it out. Depends. Denying US access to any tech hurts them more than the armies that don't have such high tech capabilities. On the other side - if you US are mostly unaffected by that (preparations etc) they will be so far ahead that cleaning up the debris will hurt US superiority. So - who will be ok with cleanup in that current moment can vary a lot. To see a lot less serious mess unfolding in real time - Syria. While the end game is clear for all - get rid of ISIS and install strong stable government, everyone is moving to get advantage and increase its bargaining pool.
  - maxerickson 11y ago
    Everyone with space launch capabilities would be fine with it, and they are also the relevant parties when it comes to treaty issues. I don't think Russia and China would want to leave junk up there, I don't think any one else is even questionable.
    - jerf 11y ago

rmc 11y ago

Neal Stephenson's latest novel, Seveneves, starts with essentially this premise, but with debris of the Moon.

masklinn 11y ago
The Planetes manga starts with space debris and the risk thereof, but terrorists outright attempting to trigger a Kessler event is a big subplot
- mfoy_ 11y ago
  There's an anime adaptation that's very well done. It explored the ideas of debris in space and clean-up efforts surrounding it pretty neatly.
  - shpx 11y ago
    Planetes is my favourite anime, though granted I haven't watched many. I'm not sure if the logistics make sense though, I haven't done the math but I would imagine that the amount of fuel needed to change orbits would either be prohibitively expensive or you would spend months before returning to the base station.
  - shostack 11y ago
    I loved the anime. Very much a "slice of life" in the future that was wonderfully art directed.
Terr_ 11y ago
Reminds me of the "Cowboy Bebop" universe, in which a large portion of the moon was shattered during an early test of hyperspace-gate technology.

lemevi 11y ago

If you hadn't had enough scary sounding possible future calamities that you as an individual have no control over to worry about, here's another. My anxiety system for these kinds of things broke back when peak oil turned out to not be a thing (well as described). There lots of things to be concerned about where we as individuals can make better choices, such as sustainable living and not contributing to carbon emissions, but stuff like this, while something I'm not going to ignore because it's at the very least interesting, I can't feel anxiety about. I just don't have the capacity to be anxious every minute of my life for everything that could possibly go wrong for us someday in the future.

ctdonath 11y ago
Indeed. I've lived long enough to see a whole lot of TEOTWAWKI scenarios panicked about and either were duly mitigated by sensible people or simply failed to instantiate. "Y2K Bug" was an ideal example (chronic programming flaw could have knocked out computer systems worldwide and knocked humanity back to the Middle Ages, but was recognized as a solvable problem and was indeed solved). At some point I looked at my own anxieties and simply decided to not be anxious: do what I could about what I could given resource (time included) constraints, be prepared for eventualities within reason, and otherwise carry on. My biggest recurring concern now is how I'm not anxious. Should something horrible happen, I may be disconcertingly unconcerned - having done what I could in good faith, there is/was nothing else to do but accept reality and move on.
- coldpie 11y ago
  I agree with you, but I think it is still important to be anxious and raise awareness of these problems. Without the panic, would Y2K have been "recognized as a solvable problem and solved"? We need to continue to raise awareness of these really big potential problems, even if we have confidence that they are solvable.
clarkmoody 11y ago
I can't find the source now, but some estimate that removing only a few of the largest boosters on orbit each year would decrease the cascade risk significantly, since those boosters represent a large fraction of the mass. This is a much smaller move than many other avoid-the-end-of-the-world suggestions given throughout the years. Now: better modeling would probably help us determine whether Kessler syndrome will actually happen.

riffraff 11y ago

isn't the likelihood of a cascade very low because of the orbit thing? I.e. object X hits Y, they both spin out of control but most likely they will either go towards earth or go away from it, so they chance of them hitting something else is very limited, it's not like billiard balls that would eventually hit each other.

Zitrax 11y ago
I assumed that if object Y hits object X it would result in a huge number of particles from the collision, each with a chance of hitting something else eventually. Even if a single one of those particles hit one of our precious objects in the next 20 years it could be devastating.
- msandford 11y ago
  But as it gets cheaper to put new satellites up, cleanup gets cheaper too. And if access gets cheap enough I could easily see an international treaty mandating that all satellites have an EOL burnup system installed. When 20kg costs $2mm a lot of people will balk at the idea. When 20kg costs $200k or $20k it's a lot easier to require people to include it. It could even be a bolt-on kind of thing, separately powered and controlled such that it doesn't have to be re-invented for every new satellite. Also with access being cheap enough we could start doing active cleanup, beyond just not making the problem worse. Aerogel is supposed to be great for capturing particles because it's basically frozen air. We could build a space-based aerogel factory and ship silicon ingots up which then get turned into aerogel panels to be used as replenishable armor for the factory. And once you have the factory up you just start making the area that the armor sweeps bigger and bigger. Build out sideways to clear a particular orbit faster, build up or down to clear orbits of various heights. It'd be insanely expensive right now, but if launch costs come down to $100/kg or $10/kg it starts to look reasonable.
spatulan 11y ago
In 2007, the Chinese tested an anti satellite missile against a weather satellite. The missile contained no explosives, it relied purely on kinetic energy. The collision released 2,300 pieces of debris that were large enough to be tracked, so about golfball size or larger, and probably many times that number that are too small to track.

chrispeel 11y ago

I was just listening to a show about predictions of the end of the world (http://radiowest.kuer.org/post/latter-day-predictions http://radiowest.kuer.org/post/latter-day-predictions), which seems appropriate. The sky is falling!

eric_the_read 11y ago
The problem is that the sky isn't falling! It's just... sitting there.

achr2 11y ago

How does space debris reach a stable enough orbit that it doesn't just fall into the atmosphere and burn up? Also (maybe depending on the first question) wouldn't the chaotic nature of space debris collisions cause less stable orbits?

DasIch 11y ago
The debris doesn't have to reach stable orbits. The debris gets created in orbits that are already stable. It's also important to consider that stable in this context doesn't mean that the debris stays up there forever, it's just staying long enough to be a problem.
clarkmoody 11y ago
Some orbits are much higher than the atmosphere, so they are stable for a long time.

emilburzo 11y ago

Webcache: http://webcache.googleusercontent.com/search?q=cache%3Awww.antipope.org%2Fcharlie%2Fblog-static%2F2015%2F09%2Fthe-skys-gone-dark.html&oq=cache%3Awww.antipope.org%2Fcharlie%2Fblog-static%2F2015%2F09%2Fthe-skys-gone-dark.html&aqs=chrome..69i57j69i58.871j0j4&sourceid=chrome&es_sm=0&ie=UTF-8 http://webcache.googleusercontent.com/search?q=cache%3Awww.a...

brickmort 11y ago
thanks!

shiftpgdn 11y ago

If it got bad couldn't we just send up a big cube of ballistics gel with some rockets and grab everything with that?

russnewcomer 11y ago
Not to be flippant, but I don't think that would scale well enough. "Space is big. Really 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, but that's just peanuts to space." Douglas Adams, The Hitchhiker's Guide to the Galaxy

tomek_zemla 11y ago

Basically, once we are done covering Earth in garbage we will make sure we do the same to the sky... How human!

waqf 11y ago
Second Law of Thermodynamics, to call that "human" seems like unjustified exceptionalism.
kpmah 11y ago
Maybe filling our sky with junk will cancel out global warming? Yay humanity!

maxerickson 11y ago

I feel pretty confident that navigation and communications would stay about the same, at least the social aspects pointed at in the question (different tech would be used, but so what). Weather forecasting isn't all that important, warnings for hurricanes would probably be about the same. So there would be some inconveniences, but nothing huge. The geopolitics is the interesting question. I wonder what sort of imaging capability could be attained by strapping systems to commercial flights and fiddling flight paths to increase coverage. That would require international cooperation, but maybe there's enough political will to make it happen.

smacktoward 11y ago
> Weather forecasting isn't all that important Unless you travel, use energy or eat food.
- maxerickson 11y ago
  For travel, the local radar is more useful than a satellite picture or medium term forecast (where the sat data matters more). For food, forecasting lowers production costs, but it isn't good enough that our agriculture actually hinges on it. I realize my phrasing is blithe, but I simply don't see a lot of deep dependence on weather forecasts, they are used to good advantage, but would not be such a huge loss.
  - dalke 11y ago
    Local radar doesn't give IR, which among other things gives sea information. Quoting from https://en.wikipedia.org/wiki/Weather_satellite#Infrared_spectrum https://en.wikipedia.org/wiki/Weather_satellite#Infrared_spe... : > Infrared satellite imagery can be used effectively for tropical cyclones with a visible eye pattern, using the Dvorak technique, where the difference between the temperature of the warm eye and the surrounding cold cloud tops can be used to determine its intensity (colder cloud tops generally indicate a more intense storm).[10] Infrared pictures depict ocean eddies or vortices and map currents such as the Gulf Stream which are valuable to the shipping industry. Fishermen and farmers are interested in knowing land and water temperatures to protect their crops against frost or increase their catch from the sea. Even El Niño phenomena can be spotted. Local radar doesn't give condition more than about 100 miles off-shore. It becomes more difficult to figure out if there's a front or severe storm coming to land. Consider, for example, a small typhoon somewhere in the Pacific. https://en.wikipedia.org/wiki/Cyclone_Tracy https://en.wikipedia.org/wiki/Cyclone_Tracy was spotted by weather satellite on 20 December but wasn't seen on radar until 22 December. It hit on 25 December. With weather satellites, it's easier to route shipping and flights around a disturbance. Weather satellites are also used to identify new volcanic eruptions and route around their effects (http://www.sciencedaily.com/releases/2014/09/140926091334.htm http://www.sciencedaily.com/releases/2014/09/140926091334.ht...), and detect wind patterns over the ocean. At some point it depends on what "deep dependence" means. It can easily be defined to make what you say be trivially true, and therefore uninteresting.

applecore 11y ago

Do we really believe that science, if faced with the immense challenge of orbiting debris, won't find a way to regain access to orbit? When did we become so pessimistic?

creshal 11y ago
Of course we'll find a way. But who will pay for it?
kohanz 11y ago
I think the point is that this problem is a lot easier to deal with before it is actually a problem. Reminds me of climate change, in that way.
nabla9 11y ago
Economics is usually more important factor than science. Science provides possibilities, economics selects those possibilities that are realized. Instead of building those sci-fi space stations and exploring plants that has been scientific possibility for decades, we have realized and exceeded our sci-fi dreams in computers, internet and mobile phones. If billion people spend $10 per month on something, there is economic incentive to spend billions in technological research.

sneezeplease 11y ago

I cant believe you tech worshiping nerds think satellites are real. Look in to how hot the thermosphere is, theres no way satellites exist. Go try and find any picture of a satellite out in space, its all cgi and paintings.

russnewcomer 11y ago

I'm not read enough to understand exactly how the Kessler Syndrome scenario cstross proposes would interact with GPS, but significantly naval spending by the Superpowers is the big powers is the major effect I can easily see. When you have to protect undersea communication lines for military command and control (assuming the Kessler Syndrome would be a convenient way for hostile nations to launch attacks against other nation's orbital assets), meaning drone warfare becomes untenable outside a direct LOS engagement if undersea lines are not secured. I also think there would be a major issue with weather satellites and prediction, causing a significant investment to be made in weather radar and alternative weather prediction and monitoring strategies.

creshal 11y ago
> I'm not read enough to understand exactly how the Kessler Syndrome scenario cstross proposes would interact with GPS GPS needs 24 satellites to function as planned. (It might work with less, but 12 seem to be the minimum under optimal conditions). • If a Kessler cascade happens in the GPS satellites' orbits, it will rapidly disable existing GPS satellites, and deny access to said orbits for new satellites. Replacements could be launched into safe orbits, but this will likely take years, and those orbits will have a faster decay rate and less visibility (so you'd need even more satellites). • A Kessler cascade in LEO will likely deny access to higher orbits, so while existing GPS satellites will continue to function, they cannot be feasibly replaced once their 10-30 years life span is exhausted.
- marcosdumay 11y ago
  I don't get how a Kessler cascade in LEO would deny access to higher orbits. Can collisions become so common that staying in LEO for a fraction of a day is already dangerous? How many debris are we talking about here?
Symmetry 11y ago
GPS is all in MEO rather than LEO. It's a larger volume with less stuff in it so there isn't much chance of getting Keller Syndrome up there.

outworlder 11y ago

We'd have to adapt. Plans to colonize Mars and the like would have to be postponed. Important satellites would have to hug Earth's atmosphere to stay (somewhat) safe. They could look somewhat like this: https://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State_Ocean_Circulation_Explorer https://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State... More fiber optic cabling would be required. Local stations to retransmit information would have to be created (or existing infrastructure, such as cellphone towers, would be retrofitted). And so on. We'd do fine, I guess. But not without an enormous cost.

jcromartie 11y ago

Isn't most of the debris moving in the same direction? I'm imagining that being in orbit is like being on the freeway, where the traffic is all running the same direction. Yes, getting hit by a car going 70 MPH would normally be catastrophic, but two cars bumping into each other around 70 MPH is not always a big deal.

mark-r 11y ago
I believe that would be true of geosynchronous satellites, otherwise there would be no benefit to being geosynchronous. Any pieces that break off should alter their orbit enough to be out of the way. Edit: I just got dinged for this comment, if there's a flaw in my reasoning or a study that refutes it please let me know.
ceejayoz 11y ago
Enough satellites are in polar/retrograde orbits to be an issue. Explosions from Chinese/US anti-satellite tests and accidental collisions go every which way, as well.
- Symmetry 11y ago
  The satellite that the US shot down was in a swiftly decaying orbit. That means that the periphrasis for all the debris was at least that far down and with the smaller ballistic coefficient of the debris it's all gone now.
baq 11y ago
one degree of inclination difference with otherwise similar orbital elements upon impact translates to about .5%-1% of energy of a head-on/t-bone impact. at orbital velocities this is still mindblowingly devastating. you've basically reduced a 8km/s impact into a 40-80m/s which is in 90-180mph range. result is lots of debris created in both orbital planes as both sats (you're comparing cars, so i assume you want sat-sat impact) are totalled, solar panels shattered, etc. and that's basically the smallest accidental collision in space you can imagine (not counting failed berthings/dockings and the like).
11y ago

clarkmoody 11y ago

Researchers at Texas A&M University[1] have been working on this problem with NASA JSC for years. The approach has been to go after the large spent boosters (a few thousand of them), since they contain the most mass of any class of debris objects. Each upper-stage booster has a rocket nozzle that makes a great target for grappling. As other comments have noted, the main issue is actually deciding to spend money bringing down orbital debris. As with many other issues we face, this is another case of kicking the can down the road, and we may not address it until the collision cascade has started :-/ [1] http://lasr.tamu.edu/research/proxops/#Debris_Removal http://lasr.tamu.edu/research/proxops/#Debris_Removal

__d 11y ago
Having expended vast amounts of energy to get it up there, it seems a shame to bring it back down again. I'm hoping to see a cleanup driven by a desire to reclaim the constituent metals, etc, without a need to boost them out of the gravity well.

freddref 11y ago

If space debris can be detected and tracked, a fleet of garbage collector/deflector bots could clean the path in front of functioning satellites. Though a giant block of expanding foam might be cheaper.

tylermauthe 11y ago

Future business opportunity: Space Garbage Reclamation. I'm only half-joking here, it would be a net benefit to anyone trying to put things into space by avoiding Kessler Syndrome and the junk itself could be valuable. Once we have space-based fabrication facilities, any materials that are already in space are much more valuable than those same materials on Earth.

zacharypinter 11y ago
I believe there's an Anime series around this idea: https://en.wikipedia.org/wiki/Planetes https://en.wikipedia.org/wiki/Planetes
Shivetya 11y ago
Space borne or even eventually ground base lasers could sweep the sky

natch 11y ago

The worst collision so far was deliberately caused by the Chinese military. Good job guys, way to show what a great country you are: https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_missile_test https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_mi...

thu 11y ago
You should read the parts where it says US has done similar tests and that "In response to US weaponisation of space, the Chinese started a space defense program, including anti-satellite defense." That being said, this is a great example related to the OP (e.g. number and sizes of tracked debris and for how long they remain dangerous).

paulsutter 11y ago

> Postulate a runaway Kessler syndrome kicks off around 2030, at a point when there are thousands of small comsats (and a couple of big space stations), ranging from very low orbits to a couple of thousand kilometers up. Human access to space is completely restricted; any launch at all becomes a game of Russian roulette. Postulate? This article hasn't got a shred of calculation to give any hint when this becomes a problem. Is this a 2030 problem or a 2300 problem? No data.

freehunter 11y ago
It's a problem right now because we just don't know. It could happen tomorrow. It could happen in 2300. It's all chance. Like the example given of running across a field while machine guns blaze away. You might cross 100 times and be safe. I try to cross once and I'm gone. All we know is, our odds increase with each item we put in orbit.
- JoeAltmaier 11y ago
  Its measurable and predictable. A model has to be built is all. Nothing magical or unknowable about it. I agree with the idea that we should, fairly easily, be able to answer questions like "when will this become critical" Further, its not a single happening - its a process modeled by a differential equation including terms for orbital decay, particle distribution over time, solar wind, new launches etc.
maxerickson 11y ago
The author is trying to start a conversation about the societal implications, not trying to analyze the Kessler syndrome itself.

valarauca1 11y ago

Couldn't researchers just adopt basic fission calculations to work for this application? I mean its fundamentally the same problem. Large particles being impacted by smaller particles causing them to emit more smaller particles. I tried to work though this yesterday, but I'm not sure how to translate the free-space constant to orbital-scale units.

marcosdumay 11y ago
At the very minimum, the elasticity is completely different. Also, in one case particles are hold within a lattice, while on the other they are completely free to move in any direction. And there are orbits to think about, while on the other case the deciding factor is particles leaving the lattice... Well, I don't think calculations would look any alike.
- valarauca1 11y ago
  From the preservative of satellites (and items ejected from them) in the same orbit, they're motions are fixed to each other. They only appear in motion from a 3rd party observer on the ground, or in a different orbital.

nabla9 11y ago

BRUTE FORCE MODELING OF THE KESSLER SYNDROME, Lawrence Livermore National Laboratory http://www.amostech.com/TechnicalPapers/2012/Orbital_Debris/NIKOLAEV.pdf http://www.amostech.com/TechnicalPapers/2012/Orbital_Debris/... Interesting paper where supercomputer was used to simulate the increase of particles greater than 10 cm in size over 100 years with high temporal resolution. Results for BAU (business and usual) and BAU-d business as usual with decreasing breakup rate don't look so good: "linear growth of the catalog size with time, to ~65,000 objects by year 2100." 100 years from now there will be 50 conjunctions per day and 3 collisions per year.

nateberkopec 11y ago
I don't understand - what's the difference between a conjunction and a collision?
- realquick81 11y ago
  The words are self descriptive: Collision = con + laedere = strike together (two things strike each other) Conjunction = con + iungere = join together (two things become joined to each other)
- panzagl 11y ago
  Conjuctions are when the objects are within a certain distance (basically a safety margin, usually several kms), a collision is an actual strike.
- nabla9 11y ago
  Conjunction is close approach between two orbiting objects. Satellites may have to execute collision avoidance maneuvers and burn expensive fuel resources if the predicted trajectory brings debris too close for comfort.

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snowwrestler 11y ago

> Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it's traveling at orbital velocity, Relative to an object stationary on the ground, yes. But every satellite is already moving at orbital velocity itself. If two satellites are orbiting in the same direction and one blows up, its pieces will not hit the other with full orbital velocity. > any launch at all becomes a game of Russian roulette. Maybe if the situation gets this bad, then the mitigation actually gets easier: just send up a lot of cheap big rockets on parabolic trajectories to orbital height. They will get hit, all the pieces will fall below orbital velocity, and fall down into the atmosphere. We could even launch cheap parabolic trajectory "blockers" to clear holes in the debris field for launches to higher orbits or escape trajectories.

titzer 11y ago
They aren't all moving in the same direction. Have a look: http://earthobservatory.nasa.gov/Features/OrbitsCatalog/ http://earthobservatory.nasa.gov/Features/OrbitsCatalog/

daenz 11y ago

Dumb question, but can't we put some giant blocks of single-piece kevlar-ish material in orbit? I imagine they would have no chance for breaking apart and would just serve as "bullet" catchers for these small pieces of debris.

ble 11y ago
Hypervelocity is very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, hypervelocity is velocity so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, even metals behave like fluids under hypervelocity impact. https://en.wikipedia.org/wiki/Hypervelocity https://en.wikipedia.org/wiki/Hypervelocity The orbital velocity needed to maintain a stable low Earth orbit is about 7.8 km/s, but reduces with increased orbital altitude. https://en.wikipedia.org/wiki/Low_Earth_orbit https://en.wikipedia.org/wiki/Low_Earth_orbit

blisterpeanuts 11y ago

Eventually we'll have to use some combination of extreme ship armor (meter-thick plating of expired uranium?) and lasers that detect and zap all particles (that aren't human shaped) within 1 km of the spacecraft.

aetherson 11y ago
Boosting the kind of armor into orbit that would be necessary to deal with at least the worse scenarios is unfeasible. If you think that cost-to-orbit is high now...
- blisterpeanuts 11y ago
  True, and probably we'd have to either mine/manufacture the armor in space, or else develop some less expensive heavy lifting technologies (which is pretty much necessary anyway, if we're going to put up more manned space stations and interplanetary craft).

mark-r 11y ago

If this comes to pass, Google's project Loon won't look so looney. http://www.wired.com/2014/06/google-balloons-year-later/ http://www.wired.com/2014/06/google-balloons-year-later/ Unfortunately I don't think there's any feasible replacement for GPS satellites.

protomyth 11y ago
Ground stations can replace GPS. It might not be universal, but it for people inside a country it would work. http://www.popsci.com/technology/article/2011-08/ground-based-analog-gps-could-make-positioning-technology-accurate-inches http://www.popsci.com/technology/article/2011-08/ground-base...
GeorgeHahn 11y ago
Perhaps it would be possible to do positioning from balloons that reference ground stations or stars. It would be more expensive than the current systems but cheaper than a fully ground based system.

DanBC 11y ago

NASA has an Orbital Debris website. http://orbitaldebris.jsc.nasa.gov/ http://orbitaldebris.jsc.nasa.gov/ It has some nice photos of some of the impacts that spacecraft have had. --- Reading cstross's post at a tangent: I'm interested in how viable it is for a well funded technological terror group (like Aum Shinrikyo used to be) or "rogue nation" to dump a few tons of sand and grit (or depleted uranium, for the mass) into the correct orbits.

peeters 11y ago

> Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it's traveling at orbital velocity True, but most of the other objects near it are also at or near orbital speed, so what's the kinetic energy when compared to an object it would actually be likely to hit? (The situation in Gravity made no sense to me. The shuttle encounters the debris field every 90 minutes...why was that debris not also orbiting the earth with roughly the same period as the shuttle?) Is the solution a matter of countries agreeing to "lanes" for orbits that differ non-trivially? (e.g. 300-330km is reserved for equatorial orbits, 340-360 km is reserved for polar orbits, 380-400km is reserved for retrograde orbits)

antognini 11y ago
I could imagine that the two orbits were inclined relative to each other. If the shuttle is orbiting around the equator and the debris field is orbiting from pole to pole then you would encounter it on every orbit. (Although then you would encounter it twice on each orbit...)
SideburnsOfDoom 11y ago
> True, but most of the other objects near it are also at or near orbital speed, so what's the kinetic energy when compared to an object it would actually be likely to hit? If they're moving in opposite directions, then you just double it.
- goodcanadian 11y ago
  Actually, I think you quadruple it as kinetic energy goes as v^2.
TorKlingberg 11y ago
If they orbit in opposite directions, the relative speed is twice the orbital speed. Low earth orbits go in all kinds of directions. In geostationary orbit everything is moving in more or less the same direction and speed.
- 11y ago

seren 11y ago

On that subject, I recommend to read Spin by Robert Charles Wilson. It is not exactly a Kessler syndrome, but for some reason, one day a kind of dome/membrane encloses the Earth blocking communication with every satellite. (Physical objects can still go through as far as I recall, but since you can't communicate with them, it is not that interesting) This is good sci-fi book who won the Hugo award about the societal impact (with somewhat weaker sequel, but still enjoyable in their own way)

Symmetry 11y ago

Kessler Syndrome is a serious potential problem and it's certainly one people should be worrying about but it's mostly something that's only a problem for LEO where you have lots of things in a relatively small volume going very fast in different directions. Further out in MEO where GPS satellites are there's a much greater volume, fewer satellites, and the satellites aren't moving as fast. There's no way Kessler Syndrome is going to start there. You do have a bunch of Russian satellites that loop in fast and close by the South Pole then go high and slow over the North, letting them spend most of their time being visible from Russia. Debris from from a cascade could kill one of those, which would cause debris that would kill some but not all of the GPS sats. It would be a relatively slow process compared to what would go on in LEO, though. Satellites in GEO won't need to worry about Kessler at all. They're all in equatorial orbits, traveling in the same direction at the same speed. If one explodes its debris will only hit other satellites with the explosion velocity, not orbital velocity. So those should survive Kessler Syndrome fine, though you can't put any new ones there. Also, Kessler Syndrom isn't forever. Satellites in LEO need to boost every once in a while to overcome atmospheric drag. As things get broken up their surface area to volume ratio increases and the fall out of orbit faster. Air density falls of exponentially with height so the lower reaches of orbit will become safe first. The inner reaches of LEO might be clear quickly but I have no idea how long it would be before orbit was totally clear.

al_biglan 11y ago
Came here to say the same thing. Will also add: If LEO does get polluted, there are options to put (more expensive) satellites into MEO. At this point, it becomes an economic argument to "clean" or "push upwards"

brianbarker 11y ago

So a drone rocket that hovers around in orbit and shoots down debris sounds like another startup idea.

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yourapostasy 11y ago

Stross has rarely-found pragmatism and realism in personally-held and publicly-shared opinions about space colonization for a popular science fiction author. While professionally he writes about a human future where we travel the stars, the TL;DR is personally, he holds that with our current understanding of physics, our meat sack bodies will never colonize space. Explore yes, but mass-exodus-colonization or even plant-seed-colonization-for-independent-colony is a pipe dream; he doesn't see the proof that we are capable of even colonizing the solar system, but leaves an open door to invite in that proof. http://www.antipope.org/charlie/blog-static/2010/08/space-cadets.html http://www.antipope.org/charlie/blog-static/2010/08/space-ca... http://www.antipope.org/charlie/blog-static/2007/06/the_high_frontier_redux.html http://www.antipope.org/charlie/blog-static/2007/06/the_high... So a Kessler Cascade definitely sucks, but it isn't an "OMG, humanity loses its 'birthright to the stars'!" catastrophe because we can't GET to the stars for the foreseeable future, barring a Copernican-grade revolution in physics and accompanying engineering that opens a hitherto-unknown means of multiple magnitudes FTL transportation of the peta- to tetra-tons of mass associated with an en masse out-migration to the stars scenario. This has interesting implications (I happen to strongly agree with his analysis) for how we set and carry out future policy, if you want to figure out means of nudging our species' survival odds upwards over the long haul (Long Now Foundation, millennia to millions of years scale).

Aardwolf 11y ago

I guess all kinds of ways to handle it will appear if it is important enough, saying it will all go dark seems a bit too strong. Shielding. Special shapes to minimize impact. Smart avoidance movements. Continuous automatic cleanup of space debris. Etc...

Apocryphon 11y ago

On the bright side, imagine the orbital competitions that will result between megacorps and billionaires with space hotrods. Kessler Run, anybody?

soperj 11y ago
Kessel run?

sergiotapia 11y ago

>There are some proposals to mitigate the risk of Kessler Syndrome by using microsats to recover and deorbit larger bits of debris, and lasers to evaporate smaller particles, but let's ignore these for now: whether or not they work, they don't work unless we start using them before Kessler syndrome kicks in. Lol, ok then let's ignore proposed solutions.

rdsubhas 11y ago

Why not just launch a big magnet into orbit and stick 'em all together? EDIT: serious question

SZJX 11y ago

I don't think the human beings will have no solution in hand for such a critical situation. Clearing up the debris to a good enough extent such that we can launch things normally won't be that hard at all, when hundreds of billions of dollars are at disposal. I'm not worried about this one.