It adds to a pretty large body of literature around this subject, the gist of which is "risk is going up, but we don't really have a good way of estimating what that means in terms of actual collision rates".
At orbital velocities, you gotta know it's coming to be able to avoid it.
And a orbital velocities, the untrack-able stuff can still kill a satellite.
If your non refuelable sat is good for 6 months it probably no longer makes sense to launch it.
And now the rest of the world is trying to catch up in a sort of arms race, and not taking any care about debris concerns. The most tempting orbits are the ones in upper LEO that permit them to launch fewer satellites.
SpaceX are going to end up well under 500km (orbital lifespan: a decade) before things are finished, and they switched to very low orbit staging with SEP spiral out to reach final orbit a ways back.
China's newest constellation Thousand Sails is at an altitude of 800km (orbital lifespan: thousands of years), with a thousand satellites in the works over the next year or so and 14,000 planned, and they're launching them using chemical upper stages designed to explode into a thousand pieces at the target altitude. This is sufficient for Kessler Syndrome all on its own, without counting interactions with anything else up there. A catastropic debris cascade at 800km percolates down to lower altitudes over time and impacts.
We need viable treaties limiting development beyond 400 or 500km and we need them ten years ago.
I don't know how to sell the urgency of this predicament. You can have as many satellites as you want, a million uncoordinated bodies, at 400km because direct collision potential scales with (satellite count / orbital lifespan) ^2 . At 1000km, satellites decay so slowly we are already too crowded; we have already overused the space. We are speed-running the end of the space age and we are doing it to save a small number of dollars and to avoid a small amount of diplomacy.
This is not something we get a do-over on. There is no practical way to collect ton-scale debris at present, no way to track kilogram-scale debris, no practical way to shield pressure vessels against gram-scale debris, and even milligram-scale debris can hit with the force of a bullet. After collisions start occurring at a rapid clip, the mass of potential impactors quickly forms a long tailed lognormal distribution that denies us space for centuries.
By this do you mean at the 800km altitude?
There is no incentive large enough for cleanup (it's expensive, nobody can/wants to pay, and there are a lot of objects)
Suffice it to say this is not sustainable for megaconstellations in thousand years orbits. The responsible thing to do with that kind of scale involves reliable, redundant, prompt de-orbit of upper stages, and ideally for high-thrust, high-mass, high-engineering-margin-of-error atmospheric upper stages never to make it that far into the mission.
And what is your yardstick for measuring this? As far as I can tell this is the opposite of true. It's a popular national news meme but I don't believe it's been measured in any reliable way.
In other words, welcome various "death stars" to keep order against malicious Kessler style attacks, etc.
https://spacewatch.global/2021/12/spacewatchgl-share-chinese...
I was assuming it was to vaporize things to make the re-condensed remnants small and dispersed enough to be less of a problem. Though that seems like a tough problem if you have to stay trained on an orbiting bolt for any length of time, as the atmosphere wobbles your laser around.
This sounds like the most first-world-problem ever. It realistically affects practically nobody alive, nor would it ever. Most people will live and die on the planet's surface and never visit space, nor do they need to. There aren't too many space-based services that are really necessary to life on earth. Nobody really needs internet in the middle of nowhere. Sure, it's nice to have, but that's a first world problem that few people have.
I think the right move is to merge this approach with goo blobs. We launch a large goo blobs or nets into a few strategic geostationary orbits and now you only have to ablate objects so they hit the goo then deorbit the goo once it is full (or just leave it there) as they would be large known orbits.
As in, is it the thing that makes it so no one else has broken out of their planet to come visit us?
I could totally see it being the case that as soon as a civilization gets good enough at putting stuff into space, they start putting a lot of stuff into space and then things start crashing into each other to the point that they can’t ever launch any more things into space and become stuck. Trapped by the artifacts of their own progress
Stopping China's (highly strategic, military) satellite constellations isn't a "small amount of diplomacy". It's an impossibility.
(It's even their declared planning that deliberate Kessler cascades are on the table [0]—to try to ground this discussion in diplomatic reality).
[0] https://www.scmp.com/news/china/science/article/3178939/chin... ("China military must be able to destroy Elon Musk’s Starlink satellites if they threaten national security: scientists")
Some sort of platform that can launch 'space drones' to deorbit a dead satellite before it crashes or if something else would happened to cause a collision, that could be useful, but, probably expensive.
No GPS means no 4G and no digital TV. And technology leapfrog effect means that third world countries will be significantly affected, as they jumped directly to mobile phone: https://www.cio.com/article/194000/what-does-technology-leap... . And countries are moving toward digital TV from analog TV: https://en.wikipedia.org/wiki/Digital_television_transition because they want to free up the spectrum for cellular network.
This is bad. The transmitter towers aren't moving anywhere soon, so the obvious solution is to move them to fiber timing network. Wired is always more reliable then wireless anyway, ask Linus Tech Tips. Only China understands this though: https://www.gpsworld.com/china-finishing-high-precision-grou... and https://cpl.iphy.ac.cn/article/10.1088/0256-307X/41/6/064202 . EU is moving toward that: https://www.gpsworld.com/europe-moving-toward-a-timing-backb... . US is hopeless
You didn't need to use "greatly" here because the suggestion you're offering without being asked is not particularly great or meaningful.
> I think that would greatly aid in your online communications.
I communicate online just fine, thank you, I'm also happy to be an individual and to allow that individuality to be expressed through my communications.
Thanks again for the unwelcome and unnecessary advice. Please don't use your time to police other peoples writing. It's rude.
Anyone have an open link?
We need to start by understanding it. I'm having trouble finding this paper right now. But to date, all calculations have shown that Kessler syndrome as a generalised phenomenon is incredibly hard to trigger. Even intentionally. Especially in LEO. (Intentionally triggering it is of interest for strategic ASAT denial.)
> the mass of potential impactors quickly forms a long tailed lognormal distribution that denies us space for centuries
No, it denies certain orbits. (Again, barring some new orbital dynamic haven been discovered by this paper.)
You look at which satellites poofed and then figure out the maximum extent their debris could have drifted.
NASA has done a large amount of work to use satellite data to forecast and then work to improve agricultural yields covering the entire planet. It definitely isn’t necessary, but to dismiss the improvement that has been made is crazy, and I’d hardly call “feeding people around the world” a first-world luxury given by space travel.
The claim is that coordination is decreasing. Calling that "false" might mean coordination is steady. Calling it the "opposite of true" means that coordination is increasing.
There is no stable Mutually Assured Destruction Nash equilibrium here, if either of us does this thing it causes dramatic harm to both.
Not regarding that as a worthwhile goal is "mineshaft gap" thinking - a zero-sum mentality entirely ignoring our collective advantage in order to pursue competitive advantage.
It is perfectly feasible to run a Chinese constellation alongside Starlink sharing the same space, orbitally. Very low orbits are self cleaning.
Every collision generates hundreds, maybe thousands of pieces of debris, only the largest of which are trackable.
The worst place for space junk is high orbits it would seem like. Earth was wildly visited by an Apollo rocket stage a few years back! That is pretty wild.
Exactly that. In many parts of Africa the middle of nowhere is full of people. In many places mobile phones are the only way to get internet. I can't wait for starlink to be available here. Getting internet is not a first world problem.
Imagine a bullet circling your head at mach 25. Now imagine a second bullet, circling your head at a slightly different angle, at a slightly different distance from your head. There's a chance that they could collide, and the resulting explosion would leave a great deal of dust... on a mixture of velocities, still circling your head. Now add a third bullet, also on a slightly different vector; Make sure that it doesn't collide with any of that dust!
The actual situation is we aren't dealing with 3 bullets or 100 bullets, we have ~170 million objects orbiting the Earth, and only around 50,000 are large enough to track. They are all moving fast enough in relation to each other that a collision would result in a sizable explosion, not an elastic agglomeration. We have no way of removing them.
The good news is that there is a large volume of space for them to exist in. The bad news is that as we continue to fill it up, odds of collisions increase, and every collision spawns many, many more objects.
I’m saying send reinforced rockets through the orbits that absorb the collision instead of generating more dust. That should let you clear a path through all orbits that intersect your path. It’s hard to do and the 3d aspect of it might make it expensive but conceptually it could be a solution. Or use super powerful lasers (potentially mounted on a satellite) to deorbit the dust
Circularisation isn’t the unexpected part. Sphericalisation is. One requires orbits to desync. The other requires plane changes.
Kessler syndrome (if even achievable with current technology) would be a major bummer for science and the global economy for a couple of decades (no more Starlink, but we still have good old geostationary satellites, so no ships and airplanes would get disconnected as a result), or at worst centuries, but would otherwise not form any threat to civilization, whereas nuclear winter is already very capable of wiping it out.
What is January 6th if not a concrete example of recent political instability?
As for foreign policy consistency, 7 administrations takes us back to Reagan... The entire movement to sell out our industrial capacity to China and now the movement to try to reverse that have occurred in this time frame. This is just as important as our endless wars in the middle east, imo.
I don't disagree totally but I felt the need to put some nuance here.
I think you are really, really underestimating the importance of weather forecasting to modern agriculture (and therefore global stability), shipping and transport, logistics, energy infrastructure, and on and on.
The megaconstellation concept isn't necessary for most of the "cool stuff you can do with satellites." You might need a handful of weather or GPS satellites, and you can be more selective for orbits and lifecycle management if you're a responsible government operator.
The Starlink fiasco (and its clones) solely exists because we're abysmal at getting telecom projects built. If 80% of the country had the network connection you'd expect by 2024-- something like symmetric 10Gbps FTTH for $150 per month, and the other 20% was on a "real soon now" waiting list, there's precious little business case for Starlink.
Think about it: It was easier to plan out and deliver DOZENS OF ROCKET LAUNCHES AND A GALAXY OF SATELLITES than to tie down our existing telecom firms until they actually built a decent network, using technology like "backhoes" and "fibre-optic cables" that have existed for decades, cost next to nothing, and don't require literal rocket scientists to deploy.
The American telephone network under Ma Bell was almost a Wonder of the World for its scale, resilience, and universal accessibility-- and in barely one generation we ripped it out and failed to replace it with anything comparable.
I would argue the case there's a marginal case for one modest capacity public data constellation. The business case is basically Iridium warmed over-- for the places where there is no other practical option (ships at sea, completely undeveloped territories)-- you can pay $10 per gigabyte for 128k down, or to support some form of 911 outside of cell ranges. Arguably, we already had the infrastructure for that with the pre-Starlink satellite products (Viasat/Hughesnet)
But we hardly need every major power (and probably a bunch of private competitive duplication) blasting crap into space to make the deluxe version that's still not as good as a fibre running to your home.
I don't get the impression that you've looked at the physics of orbits.
Everything up there carries tremendous kinetic energy.
It would be pretty hard to build something strong enough to take on intentional collisions, let alone large debris.
Fun reading: https://www.esa.int/Space_Safety/Space_Debris/Hypervelocity_...
Here's a picture to illustrate: https://www.esa.int/var/esa/storage/images/esa_multimedia/im...
"Just" how? Orbital collisions happen at an average of 10km/s, you're going to make what, some kind of sponge that can get hit by a chunk of satellite going ~8x faster than a bullet and absorb it and slow it to a halt without fragmenting at all? Good luck.
> Do that a few times and then all other rockets just reuse the path that was cut?
Things in orbit are constantly moving, you can't "clear a path" any more than you can, IDK, make a safe route through a forest by walking through it once and moving any bears you encounter a couple of feet.
It doesn't even need to be factored in, though, if different planes are colliding with each other and energetically generating a spectrum of new orbital vectors (many less than circular) from impact. This effect colludes with altitude drop from orbital decay and the tendency to circularize orbits by perigee drag, to make it so that higher orbit debris percolate into lower orbits over time.
"Clearing a path" is something you can do with a bulldozer through a traffic jam, but imagine clearing a path through a belt road by driving through the flow of moving traffic sideways at speed. Ultimately you can't hit every car in the outer lane with just one bulldozer, and the cars will close in and fill gaps because they're moving at slightly different speeds.
The easy elastic collisions you're imagining also just can't occur at these relative velocities. When something hits it looks more like an explosion than a "catch". If you shoot a local stone monument with high explosive artillery shells what happens? Does it reduce the number of things flying through the air or increase it?
Either you get along or you do not get to be a spacefaring civilization.
Launching a nail bomb into orbit would've been possible as soon as we were able to get into space, the only question is motivation. A terrorist state, say North Korea, threaten the rest of the planet and demand concessions once they're able to get any significant mass into orbit.
You're saying "nothing bad will happen because nothing bad has happened so far". There's a first time for everything.
"The most tempting orbits are the ones in upper LEO that permit them to launch fewer satellites."
Higher altitude => wider coverage => fewer satellites
Both of which demonstrate that our species is much better at understanding how to scale madness and destruction than how to scale sustainable activity.
However a rocket is spending in a seconds in that same orbit. Thus a rocket passing through may only have say 1:10,000 odds of a collision on its way to mars while satellites are getting shredded.
With GEO sats, unless you go for direct GEO insertion, it might still have issues reaching the final orbit. And even at GEO, there could be a debris cloud as well causing issues, at least until the sun and moon gravity perturbs it enough.
- "Launch their satellites for them, at 400km."
No reasonable person would help their adversary build powerful weapons that could immediately be used against them. The point of satellite constellations—Chinese or American, either—is to create undeniable, high-bandwidth communications for armies; to create real-time (as opposed to sporadic) satellite imagery for armies; to create, in short, an overwhelming situational awareness advantage in a conventional war.
- "Give them cash or territory."
We are not giving away countries.
Put 100k boost-phase interceptors into LEO. Permit them a fixed quota of launches per year, shoot down the rest. Pax Americana.
Not a satellite expert, but I understand GEO clears out relatively fast (~decades), because of those 3-body perturbations,
https://www.agi.com/blog/2020/07/geo-satellites-don-t-decay-...
We stand to lose a lot more from a space war, right now, than anyone else. We (US/west) hold the lion's share of space commerce and orbital launch capacity. "Earth orbit is free and open for everyone" is more than Star Trek idealism—it's a precedent we've set that benefits us, especially.
No such material exists, nor can it be made from any matter that is based on electrons bound around a nucleus — the force of impact will break any such material.
> It’s hard to do and the 3d aspect of it might make it expensive but conceptually it could be a solution.
"expensive but conceptually it could be a solution" is also why we don't have an Orbital Ring instead of rockets: https://en.wikipedia.org/wiki/Orbital_ring
The cost requirement for getting something to space with enough momentum to do the cleanup, even if it was able to survive the impacts, would be comparable to the entire cost of getting the stuff constituting the mess into orbit in the first place: bad enough to be prohibitive even today with relatively little mess, much worse if there's an actual Kessler cascade.
> Or use super powerful lasers (potentially mounted on a satellite) to deorbit the dust
Could work for the bigger bits, but don't put the lasers on a satellite: 1) Power is short up there, as is cooling, much easier to put a bit laser on the ground and waste some energy going up through the atmosphere; 2) if you solve that constraint, you've now got an orbital laser that's an obvious and easy-to-hit target for all foreign powers to get upset about even if you didn't want to weaponise it.
For the smaller stuff, you can't see the dust to target it in the first place.
The bully isn't going to learn with this implicit encouragement.
https://www.researchgate.net/figure/Whipple-shield-concept_f...
Orbital slots are managed by ITU United Nations International Telecommunication Union who manages availability / congestion. SpaceX reserved substantial % of sub 500 km slots. Hence PRC announching their megacontestallations to reserve 500km+ slots, specifically because there isn't enough room in sub 500km for another mega constellation so they're grabbing next best ones.
PRC megaconstellation is targetting 500km+, they're not going to put up 10,000s of mega constellation without economic reusable, hence many options under development. They're choosing orbits based on assumed reusables not current launch costs / vehicles, which btw LM5 is $3000/kg, or ballpark enough to F9/kg for disposable megaconstellation launches despite cost. But bottleneck is resusable vehicles can sustain the required tempo for megaconstellation that disposable can't.
Basically every other interest on earth is going to see this as the west exploiting space then pulling the ladder up after them. It's the same reason why hoping developing countries will stop using coal is ridiculous. We need to foot the bill to clean up after ourselves or people will just ignore us and do what they see they need to do regardless.
And even then the negotiation process will take decades so that means no LEO satellites available for anyone for several decades.
The world is already dangerously unstable and here we are discussing new ideas on how to make it more so.
If so then what countries in Europe (sans the Balkans) or East Asia do you think are less politically stable than the US?
So unless somebody maliciously launches e.g. a bunch of ball bearings in the same orbital plane but opposite direction, the chances of "wrecking GEO" seem much lower (although the consequences would, as you say, probably be much more severe and long-term).
So you don’t think the 1:10k odds compounded over every space launch are enough to be a problem?
I was thinking that maybe as you get to a scale where you have things coming and going all the time, and each time they have to pass through the debris layer, and if they have bad luck they become part of that debris, that eventually you get to a point where even just passing through that layer is untenable. But you don’t think that is likely even for a society sending out interplanetary vessels every day?
Being hit isn’t the same as being destroyed, you can track and avoid large objects, and small are survivable in the short term. https://en.wikipedia.org/wiki/Whipple_shield Collisions however keep adding up until a satellite fails.
Second an outbound rocket need not be in orbit, so if it is destroyed that may not result in extra orbital debris the overwhelming majority of mass could fall back to earth.
Also, Kessler syndrome isn’t a forever thing. There’s a reason planets have rings not debris clouds. It’s possible to have a steady state where the rate you’re making it worse is balanced with the rate things are naturally clearing.
> all the orbits under 500 km are also annulled and put up for negotiation
The real issue is regulatory, not technical. See https://news.ycombinator.com/item?id=42199498
> plane change
Roughly 3 minutes in: https://www.youtube.com/watch?v=9cd0-4qOvb0
Targeted space junk disposal in GSOs appears to be quite practical. The easiest major orbital changes for an SEP stage to burn, structurally, involve lowering periapsis from high orbit.
How does this make sense? Other countries could clearly decide however they like, because they don’t need to come to the negotiating table.
[1]
> What emerged out of this economic crisis was a reform movement led by Mohammad Khatami, who won a presidential election in 1997 on promises to cultivate civil society, fix the economy, and replace a "clash of civilizations" with a "dialogue of civilizations." The cultural transformation unfolded over the next several years was remarkable. The share of university graduates who were women topped 60 percent, a new generation of intellectuals began to favorably cite Western philosophers, and religion more or less stopped policing the daily lives of most Iranians. By 2000, the Economist was reporting that according to Iran's own clergy, fewer than 2 percent of Iranians attended mosque on Fridays. On the economic side, the neo-liberalization of Iran intensified; small-scale factories were exempted from labor laws, and state-owned industries were privatized (loosening the state's grip on the economy was thought to be the best way of decreasing state interference in Iranians' private lives). Iran's relationship with foreign nations, even the US, also improved considerably. President Clinton eased up on the economic sanctions that Reagan had put in place in 1987, and Khatami appeared on CNN to talk about his admiration for the American nation and people. Al Qaeda's attack on the United States on September 11, 2001, was met with a massive outpouring of sympathy for America in Tehran, with enormous crowds holding candlelit vigils and some sixty thousand people observing a moment of silence at a soccer match on September 23.
[1] https://www.nplusonemag.com/issue-37/politics/we-used-to-run...
President Bush certainly bungled the situation as well.
However your idea of "annulling" permits already given out isn't necessary, or politically feasible, or even desirable.
"Annulling" is just one HN user's jealous destruction fantasy.
I was the one who implied the status quo, i.e. countries putting things into orbit way above 500km and nobody stopping them, is likely to prevail… with even the next best alternative very unlikely to happen.