10 ms·
The misunderstood Kessler Syndrome
- bell-cot 2y agoThe article has a nicely sober sub-title, and at least talks about people doing actual calculations & simulations. (Vs. the usual dramatic doom-mongering.) I'll rate it 8/10 in its category...but that's really not saying much.
- h2odragon 2y agoAtmosphere rarely gets mentioned, in "space pollution" stories. It can be a factor in "the sky is falling!" stories: (2022) https://www.smithsonianmag.com/smart-news/hubble-is-slowly-falling-spacex-wants-to-give-it-a-boost-180980891/ https://www.smithsonianmag.com/smart-news/hubble-is-slowly-f...
- delichon 2y agoEconomics could solve it, if orbital manufacturing finds it cheaper to collect space junk for raw material than to boost it to orbit or mine it from asteroids. If we can defer it long enough to get to that stage an incipient orbital buzz saw may have a silver lining.
- exe34 2y agocollecting objects at orbital speed from any direction is a tricky engineering challenge.
- bell-cot 2y agoUnderstated. A Falcon 9 can put ~20,000kg into LEO for ~$40M - so $2/g. The cost of deorbiting little space junk is many orders of magnitude higher than that. And deorbiting is far cheaper than capturing and recycling.
- sebzim4500 2y agoNot sure where you are getting the $40M. That's much less than the sticker price, and probably much more than the actual marginal cost of a launch.
- bell-cot 2y agoYou are correct (as far as I know), but: https://en.wikipedia.org/wiki/Fermi_problem https://en.wikipedia.org/wiki/Fermi_problem No point to looking up the current exact price, nor payload, when removing orbital junk is multi-million-dollar ante game, and state-of-the-art is "a few engineering prototypes exist". The bottom line (that we're many orders of magnitude away from economically recovering small space junk as raw material) would be true whether the cost of launch was $20/g or $0.20/g.
- asadotzler 2y agoFalcon 9 can put 17.4 t to LEO (demonstrated with a 2023 Starlink launch) for ~$20 million (estimated SpaceX cost, not retail price) which is closer to $1.15/g. Again, that's cost not price. That's what the state of the art can do in a best case, but probably highly repeatable and reliable scenario, today.
- simiones 2y agoI'm pretty sure that collecting objects from a field of debris where every object is moving at speeds of up to 30,000 km/h relative to other objects, in random directions, is much more of a scientific challenge before even looking at economic incentives for it.
- Me1000 2y agoExactly. People forget (or simply don't know) that orbital plane changes are incredibly expensive from an energy perspective. It's not like you're walking down the road picking up trash in a row, you have to adjust your orbit, canceling out movement in one direction while adding movement in another. And it takes an incredible amount of energy even for minor plane changes.
- lazide 2y agoEspecially since most of the debris is widely spread, and often as small as a pea.
- ooterness 2y agoExactly. It's like mining lead from the bullets flying through an active battlefield. There's material there, but it's moving in different directions.
- bsder 2y agoI thought that the only effective way to clean this is ground-based focused energy. And even that has absolutely absurd energy requirements. Everything else is in the realm of science fiction.
- deleted 2y ago[deleted]
- schiffern 2y agoPeople are focusing on the technical challenge, but there's a deeper issue with this idea: using mining is solving the problem "by side-effect." The way economics is supposed to solve this sort of problem is via liability (and probably insurance). This doesn't require solving the space mining problem, just an actuarial problem. But of course, the problem is that certain international actors wouldn't accept any sort of rules-based accountability for damage when it's caused by their space junk.
- adolph 2y ago> The way economics is supposed to solve this sort of problem “The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design.” ― Hayek
- KennyBlanken 2y agoYup, just like the problem with plastics is "solved" by recycling, which only manages to handle a fraction of the plastic generated, doesn't address microplastic pollution, and the economic viability of recycling is incredibly poor, in part because the polymers break down quite a bit with use/age/reprocessing.
- trashtensor 2y agoPlastics, climate change, we have a number of these problems that get worse over a long enough time scales that there is no incentive for the people in charge of our economy to fundamentally change their behavior. I find "economics will solve this" arguments really dubious.
- exe34 2y agothe market only really works when the perpetrators pay the cost.
- bryanlarsen 2y agoRecycling works great for lots of resources: lead-acid batteries, steel, aluminum, etc. Just because it doesn't work well for one resource doesn't make it non-viable.
- raincole 2y ago> if orbital manufacturing finds it cheaper to collect space junk This is a giant "if" that generates enough gravity to pull all the space junk into a ball.
- deleted 2y ago[deleted]
- PaulHoule 2y agoIt is not always cheap to change orbit around Earth, the old Heinlein quote: "If you can get your ship into orbit, you're halfway to anywhere." is mostly wrong. If you wanted to send up a satellite to pick up little bits of trash and bring them to one place for processing you would have to use fuel to maneuver from one to another: it is cheap to change the https://en.wikipedia.org/wiki/True_anomaly https://en.wikipedia.org/wiki/True_anomaly but other orbit changes in LEO can be about as expensive as launching a rocket up from Earth. There is no point, for instance, in sending a cargo to the space station and then launching it in a polar orbit. The space station we have has no potential as a staging area to go to the Moon or Mars because it is in the wrong orbit. The cost of moving things around is one reason why Terra is the low-cost source of resources throughout the solar system still. Now you can move space junk around without using fuel, instead you can hit the space junk with a laser which will evaporate off a bit of the surface and push it: https://arxiv.org/abs/1110.3835 https://arxiv.org/abs/1110.3835 the usual idea is that you use this to deorbit space junk but you could also use this to change the orbit of a piece so maybe you could gather a bunch of them in one place or maybe somebody could use such a laser to engineer collisions. The laser they describe in that paper is almost like a tractor or pressor beam from science fiction.
- aftbit 2y agoI would like to see a website/app/program that can generate Delta-V charts like this one, but with different bodies and transfer orbits for scale. https://space.stackexchange.com/questions/2046/delta-v-chart-mathematics https://space.stackexchange.com/questions/2046/delta-v-chart... IMO Orbital mechanics is very unintuitive, and one of the results in people asking things like "why not shoot all of our trash into the Sun?"
- VyseofArcadia 2y agoSemi-related, there is an excellent manga about Kessler syndrome called Planetes. I would avoid the anime adaptation.
- saagarjha 2y agoWhat's wrong with the anime?
- VyseofArcadia 2y agoNothing wrong with it, exactly, but it's tonally very different, and I preferred the more serious tone of the manga. The anime has more comic relief, a more episodic story structure, and doesn't get into or take as seriously some of the themes that come up later in the manga.
- KennyBlanken 2y agoI'm guessing they hate it because the main character shifts in the manga vs anime from a middle aged widower to an (at the start of the series) annoyingly idealistic teenage girl. Although as the anime progresses, it doesn't focus nearly as much on her, shifting to one of her coworkers... Personally, her aggravating her coworkers is hilarious, and if you've ever had a late-teens/early 20's intern/employee in your workplace, you've been there, and perhaps you remember being like her - very pure and simple in your ideology and worldview. People who don't stick it out more than a couple of episodes don't get to see her character development and its message to both young idealistic folks who grow, and their cynical adult coworkers who help them achieve that growth. It's a wonderful 'soft' scifi anime with good production values and a storyline that avoids the typical anime bullshit ("enemy bad, us good...but....SURPRISE, enemy not bad!", "teenager drama involving kids who are the only ones who can save the planet/japan from aliens", and "deep" plots that are mostly just the writers creating stuff that doesn't make sense and never explaining it, with random plot twists)
- VyseofArcadia 2y agoTanabe is also a big part of the manga, and seeing her grow as a character (along with the hothead Hachimaki) is one of the best parts. If I'm being honest the anime characters that really grate on me are the added office staff. They do slowly develop as characters also, but for a decent chunk of the show they are obnoxious comic relief.
- deleted 2y ago[deleted]
- deleted 2y ago[deleted]
- everyone 2y agoI saw one interesting plan to get rid of space junk. As far as I remember it involved using nuclear bombs to "puff up" the atmosphere, locally making the top of the atmosphere higher and thus inducing drag on the junk / satellites. I think NASA did a bit of work on it, but not much. I forget what it was called. But it was the only plausible plan I have seen.
- airstrike 2y agoI love it. Surely nothing could go wrong with that plan!
- jandrese 2y agoI’d like to see the math on that. It seems more practical to pump gigatons of CO2 into the atmosphere if you want to do that.
- dylan604 2y agohumans collectively are saying challenge accepted
- mncharity 2y ago> using nuclear bombs to "puff up" the atmosphere [...] plausible plan My fuzzy impression from [1] is even the high-order-100x density increase of solar/geomagnetic storms has limited impact on lifetime (above low-LEO where there's no need). Summer day vs winter night variability is already like 10x. I'm struggling to picture high-altitude explosions raising enough mass to do more. [1] slide 12 on https://swfound.org/media/207065/02_bruinsma.pdf https://swfound.org/media/207065/02_bruinsma.pdf "THERMOSPHERE DENSITY AND UPPER ATMOSPHERIC DRAG ON SATELLITES IN LEO" Sean Bruinsma
- rini17 2y agoWell then redirect icy asteroid/comet and evaporate it to make longer lived gas ring around Earth. In either case, it's likely to have unforeseen effects on atmosphere and thus climate.
- nordsieck 2y agoI think one thing that really causes people to worry about Kessler Syndrome unnecessarily are satellite visualizations. Out of necessity, they have to display every object as at least 1 pixel. But that typically dramatically overstates the size of most objects in relation to the size or earth. Most visualizations make it look like Earth is absolutely covered with satellites. Whereas in reality, those satellites are the size of a car or smaller. 8000 cars might not even fill up a good sized stadium parking lot, much less the entire surface of the Earth. And many of those satellites are orbiting at different altitudes, so they're even more spread out than just the surface of the Earth.
- RationPhantoms 2y agoGenuinely asking, do you think that could be solved by having better orbital visualizations?
- lazide 2y agoNot the poster, but the issue is one of scale. Any visualization that showed a full orbit in a visual field that a human can see at once, necessarily has to exaggerate the size of the satellite or it would be completely impossible to see the satellite at that same scale. By millions or even billions of times. A GPS satellite in medium orbit has an orbital diameter of around 45, 000 km but is only a little over 5 meters in size. A ratio of roughly 10,000,000 to 1. If you had a visualization a meter wide of its orbit, the satellite to scale would be less than a micron in size. Completely invisible. The same problem comes up with those ‘topology of the earth’ maps that try to show how things like depth of the oceans, height of the Himalayas, etc. on a globe. They have to dramatically exaggerate the actual altitude differences for them to be perceptible. [https://www.quora.com/If-Mount-Everest-was-on-a-globe-and-was-made-vertically-proportional-to-the-globe-avg-size-how-tall-would-it-be https://www.quora.com/If-Mount-Everest-was-on-a-globe-and-wa...] The actual to scale difference in height of the Himalayan mountains vs sea level on a regular sized globe would be less than .001 inches. Completely imperceptible without precision measuring devices. Even producing such a globe accurately would be a feat of precision manufacturing. Even on a giant (1 meter) globe, we’re talking less than 1mm. Literally smoother than a billiard ball. But they are the highest mountains in the world, and absolutely breaktaking if near them. And space is even bigger, and satellites even smaller.
- ninetyninenine 2y agoA side note. There’s a whole anime about this that’s actually realistic. It’s called planets.
- VyseofArcadia 2y agoSpelling nitpick: Planetes It's Greek for "wanderers", and it's where we get the word planet.
- cletus 2y agoRelated [1] (framed in the context of the Fermi Paradox). I love these topics. While we might be nowhere near Kesssler Syndrome, the risks of space debris impacts are very real [2]. Some of the debris we've put up there intentionally and it's quite insane, most notably Project West Ford [3]. I believe that now anything put in space has to have a plan for how it will be decommissioned. For LEO probs, that typically means burning up in the atmosphere or, if it's large enough, crashing in Point Nemo [4]. For geostationary satellites, they're typically put in a disposal or graveyard orbit [5]. That doesn't solve the problem. It just kicks the can down the road. People might think you can just accelerate a bit and leave Earth but that's not how orbital mechanics work. If you accelerate a bit you've just created a new orbit. You still need a lot of energy to leave Earth orbit. It's the same reason why dumping waste into the Sun (as some like to suggest) is completely unworkable. You can't just slow down a bit and fall slowly into the Sun. You just create a new orbit. It still takes a delta-V of ~30km/s to hit the Sun [6]. Fun fact: it requires less delta-V to reach Pluto then hit the Sun than it does to hit the Sun directly. Orbital mechanics are weird. EDIT: fixed delta-V units. [1]: https://www.youtube.com/watch?v=GCCKpI80V6M https://www.youtube.com/watch?v=GCCKpI80V6M [2]: https://www.space.com/9708-worst-space-debris-events-time.html https://www.space.com/9708-worst-space-debris-events-time.ht... [3]: https://www.wired.com/2013/08/project-west-ford/ https://www.wired.com/2013/08/project-west-ford/ [4]: https://www.atlasobscura.com/articles/strange-maps-point-nemo https://www.atlasobscura.com/articles/strange-maps-point-nem... [5]: https://en.wikipedia.org/wiki/Graveyard_orbit https://en.wikipedia.org/wiki/Graveyard_orbit [6]: https://en.wikipedia.org/wiki/Delta-v_budget https://en.wikipedia.org/wiki/Delta-v_budget
- FredFS456 2y ago> It still takes a delta-V of ~30m/s to hit the Sun. That number looks like it should be much much bigger to me.
- dabluecaboose 2y agoIndeed, it's off by orders of magnitude (so probably a simple typo). The Earth orbits the Sun at between 29 and 30 km/s. It would take roughly that much dV to successfully create an orbit that intersects the sun.
- pwndByDeath 2y agoDid a simulation like the MIT one, instead of adding millions of tiny objects I tried making the thousands of current objects have a collision radius of 1-5km. Turns out space is big and I didn't have many more collisions. Mostly starlink bumping into each other gently
- klysm 2y agoI’m curious what gently looks like at these speeds
- pwndByDeath 2y agoThings in the same plane are moving at relative speeds of cm per second, so literally bumps. When things do intersect off plane its more energetic
- cubefox 2y agoI read the article, but didn't come out much wiser. Apparently it is still not clear how big of a threat a potential future Kessler syndrome is.
- travisgriggs 2y agoThe article cites a number of western assets that do things like model and study this problem. The only credit India and Russia get is for contributing to the problem by shattering things in space. There is no mention of China at all. So I’m left with a question. Is the west just doing more in this regard while non western states are behaving recklessly/belligerently OR do those nations also sponsor efforts, but don’t get mentions because the article audience is western?
- XorNot 2y agoIndia's ASAT test was a very well executed one if I recall: they launched a satellite dedicated to the task, and put it in an orbit where it would re-enter anyway and then hit it with the interceptor. As a result the debris was headed back to Earth and I believe was targeted to a known region as well. Basically a class act all round.
- dr_orpheus 2y agoYep, it was a dedicated satellite and it was an altitude of 283 km when they did the ASAT test. Everything from the test decayed within about 3 years [0]. [0] https://en.wikipedia.org/wiki/Mission_Shakti#Space_debris https://en.wikipedia.org/wiki/Mission_Shakti#Space_debris
- jccooper 2y agoDespite their intention of debris lasting a minimal amount of time ("weeks") some of the generated debris lasted for several years. While this was much better than the particularly reckless Russian destruction of K1408, orbital collisions are chaotic and energetic events, and there's no particular way to do it safely.
- pmayrgundter 2y agoDoes seem biased to not mention the prior US testing, which destroyed satellite Solwind P78-1 in 1985, leaving debris in orbit for 2 decades. (also suggestive of secret testing which may have left more) There's also an earlier Soviet program described in the article, with many space impacts, tho debris extent isn't noted. https://en.wikipedia.org/wiki/Anti-satellite_weapon#United_States https://en.wikipedia.org/wiki/Anti-satellite_weapon#United_S...
- modeless 2y agoIMO we need to stop putting satellites in orbits above ~800km altogether. No matter how careful you are there will always be accidents, and once a collision or explosion occurs in high orbit the debris is essentially a permanent fixture of the solar system, lasting far longer than a human lifetime. There is no feasible method to clean up such collision debris for the foreseeable future. Even assuming SpaceX Starship is wildly successful and launching a thousand times more mass to orbit for dirt cheap, collision debris cleanup is still infeasible. The only realistic way of cleaning collision debris is the natural way, the atmosphere. But it only works on reasonable timeframes when you're below a certain altitude. Luckily the reasons why we used to launch satellites into high orbit are mostly obsolete now. We did it for three reasons: firstly so the satellites would last longer because they are expensive, secondly to get higher land area coverage from fewer satellites again because satellites are expensive, and thirdly to make it possible to use stationary or slow-moving satellite dishes. Now that launching satellites is much cheaper and likely to get even more so, the first two reasons are obsolete. The third reason is made obsolete by modern phased array antennas that can be pointed without moving. So we don't need to take on the debris risk from high orbiting satellites anymore.
- bongodongobob 2y agoAssuming a 10m wide satellite, that's like grains of sand in a 470 foot orbit. I'm not going to calculate the odds right now but the chances of collision (assuming they're even capable of colliding in their orbits) has to be infinitesimally small. Your assertion that "accidents always happen" is doing all the legwork for your argument and it's so unlikely it may as well be false.
- modeless 2y agoNo need to calculate odds, we have data. There have been hundreds of collision and explosion events creating debris in orbit. Many if not most of them have been unintentional accidents. https://en.wikipedia.org/wiki/List_of_space_debris_producing_events https://en.wikipedia.org/wiki/List_of_space_debris_producing...
- 2y ago
- jallmann 2y agoTotal layperson here, but here are some things I have been wondering that the article didn't really address. What happens if something like Starlink is intentionally targeted during an active conflict, maybe with something like a fragmentation warhead? The short deorbit time seems like a feature, if it can deny access to space for the duration of the conflict while minimizing long-term effects. Or is there enough... space... up there that it's a non-issue? Also wondering about the impact on communications with higher orbits, eg GPS, assuming these satellites even remain intact. If LEO is contaminated, maybe with something like reflective foil strips / confetti, would signals still be able to get through? Or is that again a matter of sheer scale where it is unlikely to cover a large enough area to be a real concern?
- Retric 2y agoThe vast majority of Starlink satellites experience fairly significant atmospheric drag with their current surface area to volume ratio. Blow them up and you get more drag so they deorbit much faster. Blocking access to space that’s about specific orbits not something like an ICBM or deep space probe which only needs a tiny window to be useful. Imagine the risk of collision is 10% per day, that’s going to quickly kill any satellite, but if you only need 10 minute window you’re down to 0.07%. Communication would be basically impossible to block. 1g of matter per square mile isn’t going to achieve much of anything, but multiplying even that trivial amount by 200 million square miles of surface area = 200,000 tons or about 500 ISS’s.
- modeless 2y agoPhysically destroying one Starlink satellite is pointless as it wouldn't meaningfully disrupt service. Destroying enough Starlink satellites to disrupt service is infeasible. You would need to launch many hundreds if not thousands of interceptors. It would cost a fortune, probably a lot more than launching the constellation in the first place. It wouldn't deny access to space as you can simply launch through a debris cloud, spending only a few minutes in the danger zone which would give you a negligible collision risk compared to satellites that linger for years. You also couldn't intentionally create a debris cloud dense enough to disrupt communication or cause a chain reaction of collisions at Starlink's altitude. Space is too big.
- WhitneyLand 2y agoCan’t believe someone wrote that whole article without getting to some basic answers. What’s the probability of a major collision? What’s the probability that ISS significantly damaged? It says there’s no consensus from the models, so we can’t know what any of them predict?
- kidme5 2y agoKessler Syndrome is the main problem with Elon's plan to build a nuclear defense shield in LEO according to Grok: https://www.reddit.com/r/ChatGPT/comments/1dgyujd/comment/l8tgf79/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button https://www.reddit.com/r/ChatGPT/comments/1dgyujd/comment/l8...
- TheDudeMan 2y agoFWIW, here is where satellites are distributed: LEO:84%, MEO:3%, GEO:12% (https://nanoavionics.com/blog/how-many-satellites-are-in-space/ https://nanoavionics.com/blog/how-many-satellites-are-in-spa...) Combine that with the increased volume at higher elevations, and you get much higher satellite density in LEO. So if there is any Kessler problem, it will likely happen in LEO first. And that is the place that is the easiest to deal with (or quickest to self-heal by orbit decay).
- jjk166 2y agoWhile clean up missions might make sense for some of the largest and highest risk objects, for the much more numerous small stuff the most economical way to clean an orbit is likely ground based lasers. Whether you're ablating a bit of material on the object's surface with a quick pulse or just producing radiation pressure holding a beam on target, you can gradually lower an object's perigee until atmospheric drag is significant. It's not exactly cheap, but it's at least an order of magnitude less than in-space options. There's even a potential business case auctioning off laser time to guard specific satellites. A typical satellite costs about $200 Million to build, plus many millions to launch, and a few million per year to operate. There are about 2000 active satellites in high orbits where debris could be an issue. If operators pay $100k per satellite per year, about a 5% increase in annual operating cost and a 0.3% increase in lifetime cost (assuming 10 year satellite lifetime), that's $200M per year revenue. Assuming 300 m/s delta V to lower an object's orbit to the point it will decay naturally, and a 0.01% ground based electric to orbital kinetic energy conversion efficiency, a bank of lasers consuming 2 MW of electric power (not beam power) would be able to deorbit 140 tons of material per year. There are about 9000 tons of material in orbit, about 2000 tons of which are in medium and high orbits, so that's about 1/14th of long lived space junk. Assuming a 5 cent per kilowatt hour average electricity price, that's under $900k per year to power the lasers. Assume that's around 5% of annual operating costs, call it $20M/yr for ops and maintenance. For capex, assuming 10% laser efficiency, that's 800 kW of laser beam power, 1 kW of beam power is around $8k, though the optimal frequencies may be different, let's call it $30M. The optics and targeting system is likely to be the bulk of the cost. A university grade observatory, which is likely comparable in scale and complexity is around $500k, but this would be a custom build so it's likely substantially higher. The keck observatory cost $140M and is likely a good upper bound. Add another $30M for other technical components, and probably another $100M for non-technical aspects of the facility. Assuming capex is amortized over 5 years, we're looking at around $60M/yr for capex. For a $500M initial investment, in 10 years you're paid off and up an additional $1.5B, for an average annual return of about 15%. Not exactly the greatest investment as is, but within the realm of discussion. Further, these estimates are quite conservative and it's likely a decent portion of the initial cost could be covered by a government.
- lazide 2y ago