The world must cooperate to avoid colliding satellites and space debris | Hacker News Reader

The world must cooperate to avoid colliding satellites and space debris

nature.com

263 pointsdivbzero185 comments

From the article:

> "Collisions are proportional to the square of the number of things in orbit," McDowell told Space.com. "That is to say, if you have 10 times as many satellites, you're going to get 100 times as many collisions.

Unfortunately, any collision also increases the number of things in orbit, by breaking up spacecraft. The collision between Kosmos-2251 and Iridium 33 generated 1,300 pieces of debris in orbit. The collision between Object 48078 from Russia's Zenit-2 rocket and China's Yunhai 1-02 generated 37 known debris objects, and likely a lot more smaller untracked objects.

This is likely to lead to Kessler Syndrome, a chain reaction of collisions once the density of debris fragments above a certain weight passes a critical density:

http://aquarid.physics.uwo.ca/kessler/Critical%20Density%201...

Unless satellites are brought back to Earth, the likely path of development is that Earth will get a layer of satellite debris which makes a a good part of satellite technology basically infeasible (and any spaceflight much more dangerous).

If things got that bad I think there’d be increased incentive to invent something to clean it up. It’s a very hard problem, but it doesn’t seem impossible to deal with, I think it just requires fairly extreme intervention.

I think most orbits naturally decay, too, so there’d be a time limit even if we couldn’t clean things up.

I wonder if there isn't already a team at SpaceX or something working on a few moonshot solutions.

SpaceX probably has several rough-draft plans for mopping up dangerous orbiting debris sitting in a filing cabinet somewhere.

BUT - So long as SpaceX avoids being seen as "at fault", any Kessler sh*t-storms that occur are likely to prove huge opportunities for SpaceX, and huge problems for all of their competitors. Most debris-storm clean-up ideas require plenty of launches, to get the Wonder Widgets and Space Squeegees into orbit. Likewise the replacements for all the smashed satellites. Which replacements may be substantially heavier, due to beefed-up propulsion systems for debris dodging, armor protection around their vitals, etc.

And guess what company is the world's miles-ahead provider of low-cost orbital launch services, with an easy path to oh-so-profitable scaling up?

It's an appealing narrative but Kessler Syndrome is something that would stand in the way of Musk's primary mission of getting us set up on Mars. So even if one holds the belief that he is highly profit motivated beyond the scope of funding his main project, it should be evident that this would divert much needed resources and time that put a hamper on the Mars timeline.

I highly recommend the Starbase tour with Everyday Astronaut, especially Part 3 [0], for perhaps the best existing look into his thought process and development philosophy. Throughout the tour he comes across as humble, ready to incorporate ideas and truly entertain questions from a studied layman. What also really speaks for him is how he is treated by his employees, how he treats them, and how involved he is with the ground level of the operation. It is evident to what deep level of urgency and importance he approaches the undertaking that SpaceX is and so I do not believe they would seek to profit from controlling Kessler Syndrome.

[0] https://youtu.be/9Zlnbs-NBUI

> ...and so I do not believe they would seek to profit from controlling Kessler Syndrome.

I get the feel that logic from /Hollywood/tropes/James_Bond/ is being assumed here. In a simplistic action movie, it's reasonable to say "IF $Charismatic_Corporate_Leader profited from $Bad_Thing happening, THEN he is Totally Evil, secretly controls $Bad_Thing, and caused it to happening as part of his Evil Plans".

The Real World(tm) isn't like that. Elan and SpaceX don't control Kessler Syndrome. They are not the U.N. Space Police*. (Cripes, they can't even get timely launch approvals from the FAA, or a more sensible exclusion zone at the Cape!) "Failing" to have detailed plans & preparations for an orbital sh*t-storm - IF they don't cause it, and aren't badly damaged by it - is no more evil than "failing" to donate $75 million to African famine relief.

*Not a real thing. The point is that SpaceX ain't the law, ain't the sovereign, and ain't on some government contract to provide space emergency services & disaster relief.

(FWIW, I found the first two Starbase tour videos more interesting. Admittedly, they had the advantage of being ~3x longer.)

(Edit - formatting issue from an un-escaped '*' character.)

Perhaps instead of "control kessler syndrome" I should have used "mitigate" to be more clear in what I am saying. I am not merely implying that SpaceX wouldn't cause it to profit from it, but that they would actively try to avoid it and not let it happen through inaction. (Perhaps they would work toward solving it if it looks to be progressing quicker than anticipated and SpaceX seems best poised to tackle it)

Also a not-so-relevant nitpick - I wouldn't call Elon charismatic. Perhaps in a room full of engineers he may be. Nevertheless I still applaud him for learning how to be more personable in the corporate world.

Agreed, the first two videos were more captivating in their window into Musk's technical thought process (during which I took notes!) and the current SpaceX developments. The third struck me as a unique look into his everyday dealings while at the same time driving home how important he feels the entire undertaking is. The tone is different in the 3rd one. Much more of a serious message in contrast to the euphoric geekery in the first two.

This would be a great plot for a Bond film. I think Daniel Radcliffe would make for an interesting casting choice for Musk.

Um... Who would be the villain? What's his evil plan? My comment was analogous to "If COVID gets really bad, then Elan's Eatery has more outdoor seating and a better location for curb-side pickup than any other restaurant in town."

(Yes, I know that "Moonraker" was an extremely profitable Bond film. No matter how idiotic the [cough][gag]science in it was, Hugo Drax was trying to wipe out most of humanity.)

It sounds like you're shrugging off the problem, ignoring the advice of experts who are suggesting we need to make changes now and deciding instead that you'll ask those same experts to fix the problem later when their predictions come true; allowing intuition, incentives to continue current behavior, and resistance to change to determine your course of action.

But intuitions fail when it comes to how mind-bogglingly big and fast space is. The volume you might need to sift through has an area equal to the surface of the entire planet and a height of thousands of kilometers. The objects you're trying to grab are moving at >20,000 km/hr. Low orbits do decay naturally in a few decades, yes, but MEO and GEO orbits can take thousands to millions of years to decay.

It's like being a war zone where bullets that are fired continue ricocheting through the air for decades, and these objects are moving ten times faster than a typical bullet (and may weigh hundreds of kg). We're laying a minefield and not even keeping track of where the mines are laid. The least we can do is to keep track of and share the satellite orbits.

I’m not shrugging off the problem, and people should be extremely wary to the point where I think it makes sense to portray the situation as if we would be locked to earth forever if it got out of hand so cleanup is never necessary.

However I think people underestimate ingenuity and the ability to solve the cleanup problem if we really have to. I don’t know how much effort has really be invested in hitting that cleanup problem as hard as possible, as most discussion about it currently is theoretical, and there isn’t a lot of financial benefit to researching it.

If it starts preventing launches, then the incentives to hit the problem harder increase.

It’d obviously be better not to be forced into figuring out whether that problem is solvable, my point is it’s not set in stone that it’s an unsolvable problem, and the incentives are currently such that I don’t think we can consider possible solutions adequately explored.

I think we’re also currently tracking most existing debris fairly comprehensively/that seems to be the part of the problem currently receiving the most attention, and rightfully so. As of right now tracking debris and trying not to create more of it seems like the best way forward

The probability of a collision in meo, heo, or geo are also much lower than leo, though, because the volume of these spaces are much, much larger. Low Earth orbits end around 2000km up. Meanwhile geo orbits are around 35000km. That means that a sphere drawn at geo altitude has a surface area around 300x as large, and the volume of a 2km space above and below these altitudes is 5000x as large.

Not that it isn't something we should be concerned about, but especially the higher up you go the more that concern should be tempered by the sheer remoteness of the odds of a collision.

> That means that a sphere drawn at geo altitude has a surface area around 300x as large, and the volume of a 2km space above and below these altitudes is 5000x as large

The size of a sphere at geostationary orbit altitude is essentially irrelevant, because the only reason you go to geostationary orbit is to be geostationary, i.e. in a narrow band at the equator. The other 99.9% of your sphere is completely unused.

I suppose, but in that case relative velocities between orbiters should be quite low as well.

> Low orbits do decay naturally in a few decades, yes, but MEO and GEO orbits can take thousands to millions of years to decay.

Tens of years? Try tens of months. The ISS has a minimum mean altitute of 370 km, a max of 460 km, and within those parameters loses about 2 km per month. But the lower it gets, the faster it falls. When it's on the lower end of it's range, it falls about 3 km per month and that would accelerate rapidly if allowed to go lower. As it is, the ISS is boosted several times a year; five times this year so far: https://www.heavens-above.com/IssHeight.aspx They can go as long as a few months without boosts, but not much longer than that. Not tens of years.

The ISS is big and draggy, but the situation isn't much different for smaller satellites in similar orbits. Two test satellites for Starlink, Tintin A and B, were launched to about 500km in 2018. Both have subsequently burned up in the atmosphere after less than three years: https://www.n2yo.com/satellite/?s=43216

> It sounds like you're [...] ignoring the advice of experts

Heh, forgive me for this but it seems like you have some half-baked ideas about Kessler syndrome you gleaned from popsci media. The reality is not so simple, nor as extreme, as you've made it out to be. Your estimates for LEO are about an order of magnitude off.

All the low earth orbits decay due to low but meaningful resistance from the thin atmosphere; satellites like the SpaceX Starlink essentially are continuously "brough back to Earth" unless they periodically boost themselves up to maintain orbit height.

How quickly though? Given the size of the constellations that are currently being launched, could all of LEO become an all-destroying debris cloud, forcing us out of LEO for a year or so until it has decayed?

Possibly not a disaster now, but once people start relying on Starlink & co, it could be.

The orbital decay time depends on the ballistic coefficient of the body. This scales as mass/area, so is lower for small objects, meaning they decay faster.

If the decay time for a Starlink satellite is a couple years, fragments from a collision will deorbit much faster.

Since all debris will return to near the collision point approximately every 90 minutes, there will be further collisions of bits of debris that will tend to reduce the size of the bits of debris and speed up the decay. This will be more pronounced if the original objects that collided have orbit planes that are nearer orthogonal.

Unfortunately that's too simple: imagine a collusion with a low orbit satellite which explodes, some part of the debris will be boosted to an higher height..

No, that's not really how orbits work - after a collision or explosion, the orbit of every created shard will still pass through the point of collision, so if a satellite in circular LEO gets exploded, much of the debris will be boosted to a more elliptical orbit where the apogee may be higher, potentially much higher, but the perigee - where the majority of the drag happens, in a very nonlinear manner - will be lower than that LEO orbit or at the very worst case the same as it, having an elliptical orbit that comes down to the atmosphere, slowing down at every iteration.

There's no physical way for a single event to bring something up from a low circular orbit to a higher orbit that's fully out of that low altitude zone, that requires circularization for which spaceships need to do another burn at the opposite (high) point of the orbit.

If some circular orbit is in a LEO "gonna burn up soon" zone, then the debris from a crash there won't leave the zone because all the elliptical orbits that pass through points on that circle also have as much or more "gonna burn up soon" property.

Nice explanation, thanks for correcting my mistake.

Stars in the Milky Way form a pancake-like disc 120,000 light-years across. In ~80 years our fastest space ships will hurl along around 900,000 kilometres per hour, assuming they can leave orbit. ;-)

That makes 144 million years to travel across the galaxy. Now space-faring peoples probably won't have evolved near the disc's edge. So let's say it takes about 100 million years to fan out and colonize most of the galaxy's habitable planets.

Our one data point on technologically advanced life indicates 4.5 billion years for it to find a foothold after the dawn of a new solar system. Depending on the values you put into an E.T. calculator[1], there are between 4 and ~200 advanced alien civilizations loitering about. We know of many Sun-like stars that are ten billion years old in the Milky Way, twice as ancient as our star.

One hundred million years barely registers on either a 5.5 or a 10 billion year scale. That scale affords aliens an enormous amount of time to have sown their seeds. Hence Fermi's Paradox and hence why a Kessler Cascade setback would be a footnote's footnote on these timescales. In short, a Kessler Cascade is important to avoid, but doesn't resolve Fermi's Paradox (it isn't a Great Filter).

[1]: https://www.omnicalculator.com/physics/alien-civilization

P.S.

I describe a novel solution for Fermi's Paradox in my hard sci-fi book. Am looking for beta readers; see my profile for contact details.

I have a dumb Kessler syndrom question, but I don't really have the physics to answer it myself.

I've been told that worrying about the longer-term implications of systems like Starlink aren't so terrifying because these satellites are in LEO. Specifically, the time for that kind of junk to de-orbit is on the order of 5 years, so the worst case scenario for this junk is to wait it out.

However, if we get a good set of bouncing space junk, how does that affect this? The vectors generated from the parts two colliding small object might be in any direction, including outward?

My physics isn't that great, so I am left with this question:

is it worth thinking about the small bits of junk re-orbiting other junk? Would that push out the timeline of being able to simply wait out a incipient Kessler syndrome?

Basically when you modify an orbit with a single impulse - short rocket burn, bumping into something, etc - the resulting orbit will still intersect that point (unless you reach escape velocity). So those pieces should return to that piece of LEO, although they could still be spending large amounts of time far from there.

Kerbal Space Program intuition tells me that the worst case is that you produce a high velocity piece of debris aligned perpendicular to radial vector, e.g. aligned with the existing orbit. I think this is a fairly unlikely direction to transfer energy in a head-on collision (by conservation of momentum arguments). That debris would then traverse a fairly elliptical orbit with frequent passes at the same altitude, likely resulting in relatively rapid de-orbit. The main risk would be inducing chain reaction at higher altitudes during those few passes, which seems unlikely.

Any other debris trajectory induced by collision would hit lower altitudes in less than one orbit time (either going outwards and thus on a much more eccentric orbit, resulting in lower altitude pass in less than one orbit time, or going inwards and immediately passing at lower altitudes). So that debris seems likely to deorbit even more quickly, indicating your intuition is correct.

This all makes sense once you grok why craft need two separate boosts to transfer to a higher geocentric orbit.

Of course there's a transition point where satellites are so dense that even these short-lived trajectories are sufficient to induce a self-maintaining chain reaction of debris. I suspect that's unlikely - the probability of a collision occurring in one or two orbital periods seems negligible.

Here is my intuition: let's say two satellites impact at high relative speed to reach other in LEO. All orbits of the debris have to pass through the impact point (since all debris comes from the point of impact). Any fragments on an orbit that go much higher will have the other end of the orbit intersect the earth's atmosphere. For debris to remain up the longest, it needs to have a very circular orbit (whether retrograde, polar, whatever).

Disclaimer: I don't really know anything about the topic, so if there is something I am missing, then hopefully someone corrects me!

Putting satellites in low orbits will help, since everything in those orbits will eventually decay.

It was reported this week that there was a catastrophic collision back in March,

https://www.space.com/space-junk-collision-chinese-satellite...

A sanguine take from Casey Handmer of the JPL: https://caseyhandmer.wordpress.com/2019/10/25/space-debris-p...

Fascinating, thank you! The graded tungsten particulate cloud idea is particularly clever.

On a global perspective the interests of too many people don't align to reach any sensible consensus by conventional means. We see it with the pandemic, we see it with global warming and we saw it in general with every conflict and wars.

How can we make this happen?

Are you describing what is also known as "Tragedy of the commons"? https://en.wikipedia.org/wiki/Tragedy_of_the_commons

More like the prisoner's dilemma, no?

The "Tragedy of the commons" is a situation where choices based on self-interest converge to a negative outcome. I would not characterize our situation on global level like that.

The difference is that in our world people do express desire to cooperate, also on a global scale, but reaching consensus seems like an intractable or practically unsolvable problem. Everybody knows that cooperating lies in their own self interest, but what does it effectively mean to cooperate?

It begins at different levels. For example, before we even begin to see disagreement on how to do the the things we want, we already have no consensus on what to do in the first place.

Arguably it is exactly like the tragedy of commons - the original analogy is common pastures getting overexploited as noone wants to limit their cows so that the pasture isn't overcrowded; and in this analogy noone wants to limit their satellites so that the space isn't overcrowded..

"A resource arrangement that works in practice can work in theory." - Elinor Ostrom

Good thing that old thought experiment isn't based on empirical evidence from the real world as the first woman to win a Nobel Prize in economics showed us [1]. In both cases, it's in all participants interest as the GP said but there are some further conditions that Ostram outlined. It turns out in the real world, those conditions are met more often than not and can clearly met in this case.

1. https://en.wikipedia.org/wiki/Elinor_Ostrom#Research

It would be better to describe this as the "tragedy of the unregulated commons". In reality societies that practiced commons-based agriculture were able to collaborate effectively and limit overgrazing through laws and community norms.

Just yesterday I was ranting on hn about how we don’t value solving the big problems. But I don’t know the answers.

As an individual I try to learn and improve minimizing my negative impact and working towards a sustainable business. But that is so small and insignificant in comparison to solving problems like these.

Maybe we have to think very long term and improve the effectiveness and reach of education. Maybe the hope is that future generations are smarter and more empathetic than us.

Yeah the biggest problem is human cooperation. We will put feet on mars before we ever come close to solving that. And curiously space exploration is something that does seem to be able to inspire people to work together. Lack of cooperation in everything else is why we can't have nice things.

For one, I don't think humanity has developed thinking/communication styles and models that are sophisticated enough to engage in sufficiently cooperative behavior at scale.

For two:

> But I don’t know the answers.

Very few people are able to do what you just did: realize that they do not actually know something (see: politics, covid, any culture war topic, etc). This is actually a sophisticated skill, and to say that we do not teach it would be a massive understatement.

> Maybe the hope is that future generations are smarter and more empathetic than us.

My concern is that even if they are much smarter at what we teach, if we're not teaching the skills that are needed (which may not be definitively known yet), we would still fail.

It seems entirely possible to me that humanity is a dead species walking, but we are simply not able to properly and broadly conceptualize that to the degree necessary to wake up and change course.

Maybe this is the solution to the Fermi paradox: Advanced civilizations tend to create runaway space debris collisions, preventing them from leaving their home planets.

This is known as the Kessler syndrome. And it is not a good solution to the Fermi paradox by itself. Because it would only require a very small fraction of civilizations to avoid it to spread.

Also, Kessler syndrome doesn't keep you from leaving the planet, just from having satellites. When passing through a debris shell, as opposed to staying in it for years, the collision risk is very small.

How deep are those debris shells anyway? If we had a collision cascade in LEO, would geosynchronous orbits be generally safe? They’re pretty far apart, but I don’t know for sure.

I have no intuition for this, as it is not modeled in KSP :)

I’m trying to imagine a collision cascade that would generate debris with a significantly higher apoapsis than the original satellites… perhaps a head-on collision between prograde and retrograde orbits that ends up “squirting” some debris at extreme velocity in the normal/antinormal direction? Alternately, an object on a highly elliptical orbit (probably already space junk) near its periapsis with max kinetic energy hitting a satellite prograde?

Fermi tangent: I wonder if the Fermi paradox is a bit of a fallacy of reverse casualty in a similar vain to asking - how come we end up in the Goldilocks zone around a star? Because sentient life is not likely to appear in other conditions.

Why are there no aliens making contact? Because if there were such aliens it would be a high probability that they wouldn't want to leave earth alone and then humanity wouldn't have a chance to evolve here.

In other words, any surrounding aliens or non-aliens that have left earth alone for enough time for humans to have evolved are unlikely to suddenly want to make contact at any certain point of our development.

The speed of light alone is enough to explain it. Aliens cannot get here, and so they don't know we exist. Even if you believe there is life elsewhere, odds are it is far enough away that they cannot detect us (not to mention radio hasn't make it 150 light year yet - which is a much smaller amount of stars).

The universe is 14 billions years old. That plenty of time for a civilization to spread around all the galaxy, at least.

To be fair only some of that time is usable as you have to wait for the many conditions of life to happen. That's a lot of coincidences to wait for, then the long evolution process...

I doubt the Great Filter manifests the same way in every case.

We are going to be stuck here for a long time because of climate change, but the quantity of stored carbon from early plants here is probably not common. Other earthlike civilizations might have to switch to solar/wind/wave electrical generation sooner, or they could just listen to their scientists and drown their plutocrats.

We could also nuke ourselves.

Kessler syndrome is hardly our biggest problem.

Life always finds a way ... to take itself out.

> from early plants here is probably not common

Why not? Seems like this is exactly what would regularly happen to plant-like life.

> might have to switch to solar/wind/wave

You mean our main power generation tools until the 1900s?

And it wasn't enough power.

Economic development is largely built on increasing accessible power. We have alternatives to coal and oil now, but back in the 1900s we didn't.

Those are both made from dead trees, which for millions of years simply didn't rot; this simultaneously cooled the planet down, dramatically weakening hurricane patterns for all time until... now, while also storing millions of years' worth of solar power for our use. A lot of otherwise habitable planets very likely didn't go through that phase.

No, solar wasn't one and the other's have radically increased in efficiency and decreased in price.

A sphere of debris would flatten out into a ring. The denser the debris, the quicker the ring would form. So all you’d have to do is avoid the ring.

If I was writing a science fiction... space debris is a wonderful way of imprisoning a planet. Just put a bunch of junk in orbit, now no one can get out. Only a Han Solo type with asteroid avoiding skillz and a taste for danger.

Maybe a built-in step in the intergalactic civilisation process is launching a bunch of satellites, letting them crash, and forming an orbiting wall. This gives baby civilisations a few millennia to grow into their newfound power as the space debris forms into rings, allowing launches again.

Space junk, like everything else in orbit, moves at speeds measured in kilometers per second. There is no asteroid weaving that lets you dodge a pea-sized steel fragment approaching you at 16 kilometers per second.

You obviously have met my friend Han.

But I heard Han Solo made the Kessler Run in 12 picoparsecs!

> 12 picoparsecs

That's... a length. About 230 miles or 370 kilometers to be exact. ;)

Ask the Star Wars writers.

This is the plot of part of the Timothy Zahn Admiral Thrawn Books (Last Command). He cloaks something like 30 small asteroids and puts them in orbit around a rebel planet, but makes it appear like he might have released 100's. No one can enter or leave the planet until they are cleared, and they have no idea how many there are.

Obviously people can enter or leave the planet as long as they're willing to take a risk of dying equal to [space covered by 100s random orbits] / [total surface of planet], which is nonzero but small. If you're launching straight up, thousands of such asteroids would leave you with 99% chance of success - the trouble is that with modern standards we generally don't consider 99% good enough - e.g. for space shuttle, 2 out of 135 crashed, getting almost 99%, and that's considered not ok; but if you really need to (as opposed to launches just for PR and science) then you can definitely get out of planet 90%+ of the time.

There's a great sequence in Wall-E when he leaves Earth and breaks through the debris field. Not as you imagined but cool nonetheless.

https://youtu.be/RmG5tUCrrsA&t=60

Since space debris doesn't factor into the Insurance Underwriting pricing decisions at all of the space underwriters that I know it seems hard to believe this is a real problem.

An actuarial modifier for underwriting OOS satellite insurance: Space debris mitigation, January 2021, The Journal of Space Operations & Communicator 18(01)

>Insurers are already pulling out of the market for LEO due to the risks of collision and space debris. General market consensus indicates current premium volume about half of what it should be.

https://www.researchgate.net/publication/348151316_An_actuar...

My layman's understanding makes me wonder if we could solve this situation with a big-ass magnet in orbit, to slowly eat the debris.

OF course there would be complications from the simple fact that it would need to be very big, incredibly durable (as to not generate more debris itself), hard to launch (probably too heavy) and taken into account in all the calculations going forward.

Unfortunately it's not that simple. Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space. And the valuable space in orbit is no exception. Take the entire surface area of the Earth, and then extrude it up into a volume roughly 800km high. That's the volume you need to clear (and that's just Low Earth Orbit). There is no magnet powerful enough to make even a dent.

Yup. This is one of those issues where in most folks heads near by space/orbit is small in comparison to the vastness of space and the universe. Which it is. However its still incredibly massive and difficult to comprehend just how big it is.

I wholly agree with the spirit of your post, but I thought LEO is not that problematic because there is still atmospheric drag there that will bring down rubbish in the matter of years.

Well the clean-up problem get's even more complicated with MEO and beyond as the amount of space becomes even larger. As for space-junk not being a problem in LEO, you are correct that space junk in LEO will de-orbit in a somewhat reasonable time-frame (on the order of a few years), but that's still problematic. It would still cause the destruction of 100s of billions of dollars worth of equipment, the ceasing of any operations dependent on LEO satellite equipment, and either increasing the risk or out-right blocking launches through LEO for a number of years. The fact that this would be temporary does not mean it isn't very bad.

What if it was a billion smaller magnets? Over time they would clump up with other debris and other clumps, and the mass would make the orbits decay faster. This is my very uninformed idea, maybe magnets just have such short range that it’s not feasible at all

If you put a billion magnets in space haven't you just increased the space-junk problem by multiple orders of magnitude?

Also, heavier objects decay slower than light ones. Atmospheric drag is the driver of orbital decay. If you increase an object's mass, you lower the de-acceleration provided by atmospheric drag. Drag force scales with surface area, which increases as the square of size, whereas mass increases with the cube. Therefore, increase the size, and mass increases at a faster rate than drag force. Therefore in general larger objects decay slower than small ones

> The world must cooperate

The world can't cooperate to block spread of covid, to end hunger, to avoid global warming, to end traffic of sex slaves, to curb nuclear weapons, to end chemical weapons and land mines, ...

Heck, even in some "civilized" countries people can't collaborate to achieve mass vaccination...

Do you really have any hope we will collaborate on organizing space traffic?

> Do you really have any hope we will collaborate on organizing space traffic?

Yes. It's a much simpler problem with a lot fewer agents. Furthermore all agents share the same incentives. It is in every satellite operator's best interest to not pulverize their sat by an other one.

I think the concern is that some of those satellite operators might be totally subject to the will of some dumbass dictator or politician.

I think of that Romanian dictator (Ceaușescu) who let his totally uneducated wife design the subway system in Bucharest. It was completely non-sensical, but the engineers had their hands tied (although they did secretly build stations in anticipation of common sense coming along at some point.)

One science fiction thought is that inducing Kessler Syndrome on Earth would be a perfect way for a Moon or Mars colony to "declare independence".

If Earthlings can't get off the planet, it doesn't matter how much money, people and power they have.

>hundreds of e-mail alerts arrive each day warning of potential space smash-ups

Oh, so they could trow the Fax-machines out? Well done!

Is Email not a bit unreliable for for such a topic?

At this point I don't have much faith that there is any existential scenario that would unite the world in cooperation.

The fact that this isn't existential or even comprehensible to lets say 80% of the world's population, tells me we as engineers and designers need to plan for our technologies to be able to operate despite an inevitable cascading space collision.

> The Californian company SpaceX alone has launched some 1,700 satellites over the past 2 years as part of its Starlink network, which provides broadband Internet, with thousands more planned.

None of which are high enough in orbit for this to be an issue. They have a lifespan of 5 years or so before they fall and burn up in the atmosphere. Why was it included in the article? In the first paragraph nonetheless.

None of the other mega constellations are a problem either, they are mega constellations because they are in VLEO. You need more satellites to cover the Earth when they are lower, but they will also all fall back down, posing no long term threat.

Either the author is unaware of what he is writing about, or has malicious intent, either way, it doesn't instill trust in the article if there's no distinction of which type of orbit the satellite is in.

Sure we should be careful with satellites in more fixed positions, but the top paragraph seems like a hit piece against SpaceX, and slightly against the other companies wanting to do satellite constellations (although no name drop)

Periodic reminder that Starlink’s 12k cluster will only support ~500k users[0] at a minimum $1bn cost to taxpayers[1].

[0] https://www.techdirt.com/articles/20200928/09175145397/repor... [1] https://www.google.com/amp/s/www.cnbc.com/amp/2020/12/07/spa...

I don't see how your FUD is relevant to this discussion of space debris, please stick to discussing the article.

Please see other reply to you why those articles are FUD, they explained it much better than I could.

You must not be familiar with US broadband outcomes. If starlink actually services 500k user for only 1bn it will probably be the best ROI the US has recently gotten in terms of rural broadband access relief funds.

Also your link:

> Starlink currently has 650 satellites in orbit, with 12,000 planned by 2026. But even at full capacity the researchers estimate the service won’t be able to service any more than 485,000 simultaneous data streams at speeds of 100 Mbps.

These are not even Starlink's official numbers but some estimate by some researchers without any first hand knowledge of Starlink's tech plan. Moreover, it assumes 485,000 simultaneous 100 Mbps, a ridiculous standard, no reasonable engineer would define the max user limit of a system to be how many user can use maximum bandwidth simultaneously because that is not how network usage happens in real-world use.

My mother has had at&t dsl in the a rural town, the only broadband provider in the area, it delivers 2 Mbps *at best* aka when it works at all, even if Starlink delivers 20 Mbps with be a massive quality of life improvement.

Could we have most things in space orbiting in the same direction? That would massively reduce the risk of collisions as their relative speeds would be lower, including any fragments resulting from a crash.

That's what we do for geosynchronous orbit, for example. But if you want a satellite to fly over the entire surface of the Earth to take pictures it'll have to be in a polar orbit and those all cross at the poles where the last major collision was.

How would you cover the whole planet if things can only go in a single direction? Things orbiting around a sphere must cross paths at some point in order to get global coverage.

In general we do, because launching from west to east at the equator lets you use the Earth's rotation for a 465m/s speed boost. Launching the other direction means you need an extra 465m/s just to counteract the rotation you started out with. Polar orbits don't gain or lose much from the rotation since they're aimed over the planet's poles.

Why is everyone worried about all that junk? It's reaction mass for getting out of orbit or getting back to earth. It's mostly aluminum which melts easy. Just build a solar furnace in space that has a big 'catcher'. Make aluminum ingots. And shoot them off a spaceship which has a giant electromagnet. As you know, pulsing the electromagnet creates eddy current in the aluminum. This force has been used to weld metal

https://www.tandfonline.com/doi/abs/10.1080/0950711980945202...

The ingots fly back to earth and burn up in the atmosphere.

I think the issue is that actually collecting all those bits (if we needed to quickly clean up our orbits) would be extremely expensive. You'll need to adjust delta-v hundreds of times to match orbit and collect all these bits and pieces.

Basically - imagine dusting your place - except you're doing it in a car and you need to stop precisely over each dust mote to collect it. You're going to waste a whole lot of effort on manuvering and what to do with the junk once you've got it is actually a relatively simple problem[1].

1. You probably want to consolidate all the little bits of junk into one big bit of junk that, at some point in the future, you can scrap for orbital construction.

Wow, that's a great problem. Imagine putting up 10 junk collectors the consist of solar panels a super capacitor and a giant electromagnet-all bundled up in a little space drone. The earth tracks garbage maneuvers the drone near the orbital path of the junk, and when the junk comes close pulses the magnet. The junk decelerates, the drone accelerates and then eventually merge orbits. Junk captured. Onto the next one. As most of the acceleration and deceleration is provided by the kinetic energy of the space junk, the drone needs very little reaction mass as it only has to adjust its angular momentum now and then.

Seems inevitably we'll eventually get unsustainable levels of junk up there.

Anyone have creative ideas for how to clean all this crap up someday with "deep tech"?

Nope. The scions of HN went silent.

Ok here's a random potential solution...how about weaponized satellites with the ability to generate electromagnetic fields which can force small junk into lower orbits.

Is that a thing? Just a thought, not an astrophysicist.

Kessler syndrome is a real thing, but this reads like FUD.

We already can't work together to avoid catastrophic Earth problems like climate change, why would we start cooperating in space?

planes fly around without crashing into each other. the agencies involved work together there.

an interesting take:

https://www.colorado.edu/today/2020/05/26/solving-space-junk...

That would work and incentivize effective removal of space debris too.

It may even be implemented by consensus as it would generate revenue for the taxman.

There is a YC startup from a recent batch that want to salvage and solve that.

I feel as though there are more clickbait headlines than usual on HN lately

Space is very, very big.

The smaller the space is (lower orbits), the faster any debris decays and burns up.

Whipple shields are a thing.

I really don't see much potential for a catastrophe.

Then this will be of interest for you:

https://en.wikipedia.org/wiki/Kessler_syndrome

Here's what I've learned: there is zero chance of the world uniting behind any cause. The solution to any of these problems will be economic and out of necessity and never because of altruism.

Want to reduce fossil fuel usage? It'll only happen when cleaner alternatives are cheaper.

Climate change? Nothing will change here until there's an economic reason for carbon sequestration.

This may seem depressing but there's an important lesson here: any sense of urgency is almost always overblown. Things really do have a way of resolving themselves.

Oh and as for space debris, yes it's a problem but space is also really big. Like the US also put a bunch of copper up in space [1] that's still there.

How could this resolve itself? It'll end up resolving itself when launch costs are sufficiently cheap. We've made a ton of progress in the last few decades. IIRC SpaceX cost of getting payloads into LEO is like 20x cheaper than 20 years ago but it's still north of $1000/kg.

But what does the situation look like when the cost gets below $10/kg? That's not as unrealistic as you may think. A lot of attention is given to space elevators. I think these are likely infeasible (eg they rely on discovering a sufficiently strong material that doesn't exist yet).

But orbital rings [2]? These require no magical material and would be completely game-changing. If you have something like that just hang things off them to pick up passing space debris.

[1]: https://www.wired.com/2013/08/project-west-ford/

[2]: https://www.youtube.com/watch?v=LMbI6sk-62E

Except the pandemic shows us that we can. It's not perfect but it was at least a good effort in terms of global cooperation. Bar a few outliers.

Here's an alternative view: we may never reach herd immunity with Covid-19 and it may be something we just always have to deal with in large part because a significant percentage of the population won't get vaccinated because of side effects that, if they exist at all, are less than 1 in 1,000,000 likely to cause problems.

A large number of people have shown they're quite willing to let millions of people die rather than do something that's less risky than taking a bath.

This seems a bit exaggerated. We have maritime law, telephony agreements, bern convention, international aviation regulations that were developed over time as the need became critical.

I suspect similar will happen as space matures from frontier to settled.

All those things were seeded in different eras. The world is different today. Look at something like the Internet. Completely unregulated, and in the span of a decade has torn societies apart and undone many cultural norms because of rampant tech conglomerates doing whatever they want. And there's virtually no will at all to do anything about it. The best the US can do is inept boomer Congressmen yelling at Zuckerberg why FaceBook doesn't work on their phones.

We’ll see. The internet is or was different. It was passing bits around the globe. Making it into a turnpike would have stymied development.

Fragmentation seems to be emerging with some locales wanting or needing more local control of content. That will likely increase with the success of the GFC and its implementation in ex-USSR satellites as well as in Russia itself.

I think maritime law and safety is a good example of my point: the path to maritime law is paved in centuries of blood.

And here's the kicker: this didn't even require global collective action. This required governments to police a narrow industry. That's so much easier and yet even then it took centuries.

This is overly cynical. I agree that in general cooperation is very hard, and if things can be solved by a private entity, that is a good strategy. But the world has united behind causes before. A good example is the hole in the ozone layer. The world identified CFCs as causing this problem, and united behind the Montreal protocol. Now, the hole is shrinking and is expected to be closed by mid century [1].

I emphasize this because international cooperation is important to solve many problems. Let's not misrepresent the situation and pretend it's impossible. It has happened before, and we would do well to make sure it continues to happen.

[1]https://www.epa.gov/ozone-layer-protection/international-tre...

I bet there wasn't a refrigerator lobby back then manipulating public opinion and lining politician's pockets like it is with oil, gas, etc.

There was.

The Montreal protocol happened because Du Pont (the major maker of CFCs) made the mistake* of making an engineer their chief negotiator. When he saw the science, he basically said "yeah, we have to stop using CFCs".

* From Du Pont's point of view, not ours.

>any sense of urgency is almost always overblown. Things really do have a way of resolving themselves.

This is just another way of saying "Nobody does anything until there are bodies on the ground"

The point is to at least attempt to resolve the issue before there are any bodies on the ground. And often at the very least those efforts mitigate the number of bodies that do end up on the ground.

We already have economic reasons for all these things. Not having natural disasters and rising sea levels is an economic benefit. The problem is we don't have a _system_ that captures those benefits in a way that incentivizes actors to work towards them. The reason people don't care is because we have an economic system that incentivizes them not to care. There's nothing natural or unchangeable about this, we're just choosing not to do anything.

Fully agree with this. In previous years cooperative agreements happened via small opaque groups of people across the world who had a fairly strong hand in driving alignment. Of course this meant that it wasn't so democratic and so people have been pushing against these types of "small group" deals made in back rooms by powerful people.

That has changed such that people do not trust these groups to make these deals on their behalf because there have been bad outcomes. Now there are many more players in the conversation with their own perspectives which, while good for increasing diversity of opinion, also make the system mostly grind to a halt, which allows for groups who want to exploit their perspective to have more time to gain ground.

> Here's what I've learned: there is zero chance of the world uniting behind any cause.

What about CFCs?

> It'll only happen when cleaner alternatives are cheaper.

Seems like there's a pretty strong economic incentive for spare faring countries not to ruin space.

When I read "avoid a catastrophic space collision", I thought about an asteroid hitting the earth and endangering life itself. Compared to that, a "catastrophic collision that knocks out one or more satellites key to their safety, economic well-being or both" sounds rather like an inconvenience. Of course, it could be "catastrophic" too, but there is catastrophe, and then there is catastrophe...

Adjective inflation. Yet another consequence of the advertising business model.

Let’s say this business model were banned or didn’t exist. Getting people to choose to read your articles instead of the billions of other things they could be doing with their time on the internet would still be critical if you want to get them to subscribe.

I think it’s less to do with the business model of advertising but rather I think both that business model and the tendency towards inflating adjectives are both caused by there simply being too much information, entertainment etc. for us to make a reasonable decision of what to pay attention to. We’ve exceeded our own human capacities to process and choose between different streams of information.

That might be true, but I think if a business doesn’t rely on views/advertising to fund itself, it has more room for creating a quality brand and attracting subscribers that way. As opposed to writing clickbait headlines.

This is essentially what the Financial Times does.

Agreed. Social media's the prime example. Take Youtube's monetization. Creators are plugged into a payment per view world. That's definitely an aggravating factor, but the competition for attention is there in a similar form with or without the ad model.

I think another cause that we do not notice or just take for granted is the way our language itself is designed, it almost seems deliberately designed to support imprecision, ambiguity, confusion, etc. without it being obvious the speaker had that intent.

"the advertising business model" or the modern world more broadly?

One way or another, there's a lot of short attention span razzle dazzle these days. Maybe adjective inflation is just positively correlated with the volume of media or even of people trying to talk to each other.

It's hard competing with impending asteroid collision.

I follow many people online because I care what they have to say. Because I have read their works before and find their ideas insightful.

Not because they write clickbait headlines.

How did you know about those to follow in the first place?

They are known because 1) they care to publish their opinion, and 2) they tell others about their work.

2) is also known as marketing, a.k.a. advertising. We're often told it isn't enough to do good work to advance our career, we have to tell others about it as well. How well you present your story has big impact on how far reached and well received your work can be.

Bottom line is, you are influenced by marketing/advertising, whether you want to admit it or not. You following someone is for sure not solely because of the quality of their work.

That's how I read it too!

https://en.wikipedia.org/wiki/Kessler_syndrome

“The world” is also a bit of a stretch if you mean a handful of countries

And add to that "The world must cooperate..." you know it'll never happen.

There is so much military hardware up there, military hardware disguised as civilian, satellites that were launched successfully but publicly described as a failure/"useless orbit".

The article is essentially asking that all countries need to share the location of their nuclear subs because the Ocean is getting crowded.

Taking a step further, any nation could deliberately send a weaponized fleet to destroy satellites and then follow up with a ground strike.

Kessler syndrome itself could probably be weaponized as the cheapest superweapon ever. Say you rule over a small country, under risk of invasion by a much more powerful country, that relies heavily on GPS guided missiles, aircraft and ammunition. Probably it would not be very expensive to pick a couple fat satellites at the right orbital plane, blow them with small missiles able to reach orbital altitude, and let the resulting debris scattershot start a chain reaction to take down every GPS satellite in existence, rendering low to medium Earth orbit useless for centuries as a byproduct. Those smart ammunitions would be crippled overnight, forcing the more powerful country to risk old style boots-in-the-ground invasion, with much degraded technical support.

Antisat weapons aren't exactly simple, either, though. It's only been successfully done a few times. Intercepting something at orbital velocity isn't trivial (unless you have the capability to actually launch something into a similar orbit and effect a gradual orbital rendezvous.)

I checked, my reasoning doesn't really apply to global positioning satellites, as they have orbits far outside the LEO, about 20000 km. There's not enough mass there yet to ensure a Kessler cascade. They would have to be targeted individually, a far more difficult task.

If only there was some sort of United Nation organization that wasn’t constantly undermined and turned into theater…

That doesn't sell.

As far as I understand this actually would be a catastrophe. One collision creates a lot of debris, which then again increases the probability of further collisions and so on. You have an exponentially increasing probability of further collisions once you have one. In the worst case this could make rocket launches and satellites in orbit impossible.

I think what GP meant is that this kind of catastrophe (i.e. worst case not being able to make rocket launches or use the orbit) is still better than an asteroid crashing into the earth and perhaps causing an extinction event.

Sure, anything is less catastrophic than an extinction event. Where's your threshold? Tsunami in Indonesia? Tsunami in Fukushima? Hurricane Katrina? Do those count as catastrophes?

The problem isn't that we're no longer able to launch new rockets - it's that anything in space comes to a standstill when it gets destroyed. How about GPS is suddenly no longer usable, with planes in flight and ships somewhere on the ocean? Weather satellites allow no more observation, with no more forewarning for hurricanes, and no reliable planning of routes by either plane or ship. What will be the impact of both on modern agriculture? No more satellite based communication, etc.

We will find fallbacks. Humanity as a species is surprisingly resilient.

> How about GPS is suddenly no longer usable, with planes in flight and ships somewhere on the ocean?

Anything over land can be replaced by antennas sending out a signal from a known location, and receivers can triangulate their position from that. In-flight planes can use landmark plus compass based navigation, as well as (already existing) ground based navigation beacons, and pilots are trained on how to deal with all instruments gone dark scenarios. Ships can sail along land and use sextant navigation on the open seas (actually, the US Navy re-introduced training sailors in sextant use in 2016, to account for a no-electronics scenario!).

> Weather satellites allow no more observation, with no more forewarning for hurricanes, and no reliable planning of routes by either plane or ship.

The worst loss will be for everything over the open sea, but land based weather documentation will still be possible.

> What will be the impact of both on modern agriculture?

Not too much, technically we can gather everything agriculture needs from the ground, it's just way more effective and cheaper to observe from space.

> No more satellite based communication, etc.

That would not be a big loss, there exist (long forgotten outside of amateur radio) technologies to deal with that.

You’re correct that all of these are addressable in isolation, given time, with some loss of utility.

However, if we experience a catastrophic problem in space, we’ll have to deal with all of them simultaneously, with extreme time pressures.

The scenarios where losing GPS would cause immediate issues (naval and air transport) have built in that possibility in their training for ages.

I don’t know what straw man you’re destroying here, no one claims humans will go extinct without spaceflight. But without any doubt the loss of all space flight will have a major impact on how humanity organizes trade, communications, travel, agriculture, intelligence, war/peace, science.

And sure, ‘solutions’ will be found. Here’s another one for your list that will diminish the impact of the loss of weather satellites: just strap someone to a weather balloon and have them draw what they see, and drop those drawings until the person runs out of oxygen. Is it as powerful/convenient as what we have today? Hardly.

> Where's your threshold?

I meant world scale extinction event like https://en.m.wikipedia.org/wiki/Cretaceous–Paleogene_extinct... . A layer of sediment literally everywhere, etc.

Well then I guess in your view no human has ever experienced a catastrophe. One may think many people will disagree (me for example).

How do you call, say, a disease that kills half of all humans? An inconvenience?

I think you misunderstood? See earlier discussion. Specifically:

> Of course, it could be "catastrophic" too, but there is catastrophe, and then there is catastrophe...

I did not. I specifically asked you for your threshold between catastrophe and catastrophe.

For anyone that didn’t know, this is essentially the premise of the movie Gravity.

Gravity strikes a good balance between realism and getting the point across to orbital-mechanics-unsavvy audiences.

I mean, it definitely showed how fast and destructive space debris can be. But I wouldn't say it really achieved a significant amount realism.

and that the debris is a cloud, and that it comes around again (which is very non-intuitive for us—explosions and shrapnel generally don't hit from the same direction more than once)

https://en.wikipedia.org/wiki/Kessler_syndrome

The degree of exponential growth is still in question but the fact that it will be exponential, and will cause a huge headache eventually if left unchecked is pretty much accepted.

However, enforcement would run into the same problem that enforcing any resource in the international commons runs into, such as overfishing, oceanic/atmospheric pollution, etc.

Since it requires coordinated collective action of every space launching nation, it would require something like the UN security council to really punish nations that defect from the agreed upon program. which opens another can of worms.

Your last sentence is depressing. We can't even muster enough e pluribus unum to combat a pandemic within the one nation that holds that motto on its great seal.

Dealing with space debris doesn't require individual action from hundreds of millions of people though. It requires the governments of eleven countries with orbital launch capabilities (counting the ESA as one) to work together.

I'm not convinced that the latter is any easier than the former.

11 Countries? The UN Security Council has five permanent members and they don't always work together (any one of the five can veto resolutions against its own exonomic interest).

The UN Security Council isn't meant to be a politically nimble engine for progressive economic change; it's meant to prevent a shooting war between those major powers. Judging the UNSC by the standard of that design intent and purpose, the UNSC has been quite effective, a few regional proxy wars could have been much worse for everybody on this planet. We can call it a failure if/when America and China start WW3 and cover everybody else in fallout, but that hasn't happened yet. So far, the United Nations Security Council is working well.

There was an unparalleled global knee-jerk and the sort of global coordinated economic reorganisation we've never seen before in the entirety of history. The politics of the situation are still roiling under tensions and stresses that haven't been seen in decades. A vaccine has been rolled out roughly a quarter of the worlds population in 18 months. Vastly more efforts are hurtling through the economic system as humanity reorients its social and technological bearings. Never before has there been such a bleak future for the humble coronavirus.

The situation is neither pro- nor anti- our ability to organise at a mass level. This has been a remarkable 2 years to be alive and we've seen a level of urgent response that has never been achieved before, ever. With 3 years to prepare, anything is possible for this Kessler business.

Kessler syndrome is still limited to a range of orbits. Very low earth orbit everything simply de orbits so fast it’s not a significant issue.

Geosynchronous orbit is quite packed, but everything is moving in the same direction which prevents the kind of exponential cascade that’s so concerning. Above geosynchronous orbit’s graveyard stays clear simply because little has the energy to reach that altitude.

To some degree that's true, though collisions will likely create cones of debris that extend significantly above and below the initial orbits, and those shards could smash satellites in those higher or lower orbits, thus continuing the chain reaction.

For example: two satellites collide head-on at an altitude of 300km, creating two debris clouds that extend from 250km to 350km. Each of those catches another satellite, one at 260km and another at 320km, which fragment into debris clouds reaching from 200km to 370km (all numbers made up).

Higher orbits, like geosynchronous, have a lot more space to work with and much slower relative velocities than low Earth orbits.

That debris cloud is an abstraction, actual post collision orbits of individual objects are what matters.

At 300km satellites experience significant drag and need regular boosts to maintain orbit. After collision individual objects orbit will almost always include it’s altitude at the point of impact and generally expends above and below that point. So while yes the cloud extends to higher orbit, everything would deorbit from your example extremely quickly.

Yes, it's my understanding that, in practice, Kessler syndrome would most probably mean no geosynchronous satellites. It's slightly reassuring that that isn't as horrifying a proposition as it was thirty years ago. Recent advances would allow things like geonavigation and telecommunications to be supported with Starlink-style low orbit networks, even in that event.

Regarding simply transiting through our ex-satellite rings, I don't think there is consensus. Would it make launches beyond LEO practically impossible, or just theoretically risky in the way that blindly navigating the asteroid belt is? (You could hit something, but it's so little matter dispersed over so much space it'll probably just be extremely fine dust the shielding can handle. Probably.)

GEO is only above the equator, i.e. launches beyond it shouldn't be seriously affected if there was a debris belt, unless it reaches a significant density beyond a narrow belt.

Why the fuck do we not have a system to harvest/kill/detonate already deployed satellites??

Thats pretty fucking simple science, is it not?

It's not.

First, it's not just satellites. There's hundreds of thousands of pieces the size of a marble that'll cause catastrophic damage. And even more smaller pieces, even millimetre long bits of paint have caused damage to vessels.

Second, harvesting (presuming you mean recovery) or just killing (presuming you mean de-orbiting with atmospheric burn up) require expending deltaV. There has been some interesting proposals for using laser ablation or tether based systems, but nothing that I know of that has gone past a paper proposal.

Detonating just adds to the problem.

Thanks for the reply... perhaps a good policy would be to not allow any launch off-planet without a recovery / disablement plan?

AFAIK, all modern satellites launches require a plan for decommissioning them when they reach EOL.

The problem is 'What happens when the plan fails due to design errors/bugs/accidents/breakages/etc'.

Recovery of a satellite is incredibly expensive.

Space Satellite Recovery Startups are back on the menu boys!

We need both space junk recovery and ocean plastic recovery robots.

Recall that startup that tried to launch the ocean plastic/garbage gyre bot and it failed and no mega-corp tried to save them.

if anyone should be forced to help on this effort, it should be amazon/bezos

Well, ycombinator is a place to change the world by incentivizing profit for doing so. Get some creative actuaries to run the numbers, sell satellite collision insurance, and fund a for-profit orbital janitorial service to improve profit margin on premiums.

maybe we need something like this to learn how to be more careful before launching garbage everywhere we go

The question at stake is that there is no we here. Of course you can use the pronoun. But it does reflect the reality.

And one trap here is we must have a we. The old way is to say it must be a collective joint action is not right. There is a reason why we have carbon tax, which is a market solution to a commons issue. Not I am saying you can do that. But individual countries as individuals should be an option.

Sometimes there is no we. We may want to no we as well sometimes ;-)

We can't grow enough food to support our population without GPS, so either this leads to mass starvation or we go back to 98% of the population becoming subsistence farmers. I'd guess the former - not enough people will be willing to work that hard until it is too late - we are out of food in the middle of winter and thus won't get more for a few months. (it would be possible to force some people to starve in early winter thus saving enough food for the rest)

Maybe you’re right. As the general population uses less and less of their creative brains at some point they will be incapable of coming up with an alternative to gps (today someone would most likely have the cognitive capability to erect positioning beacons on their farm).

It isn't just making an alternative, it is rolling it out as well.

> We can't grow enough food to support our population without GPS

Can you justify this?

Edit: I mean can you provide an authoritative source or a plausible argument for believing this?

GPS allows significantly more crop to be grown on the same land. By giving plants the ideal spacing they harvest the amount of light they need without shading each other or letting light fall unused on the ground (or on weeds that in turn shade the plants). GPS also starts/stops each row of your planter as you cross already planted areas of the field, thus saving a lot of seed and in turn leaving more land free to grow crop instead of seed. GPS also always fertilizer to be placed where needed thus not over fertilizing some areas while under fertilizing others.

So far so good, but none of that answers my question.

According too this article it seems it could very well create some serious issues.

https://www.space.com/space-junk-collision-chinese-satellite...

It is kind of funny how humans cannot exist without putting garbage all around the places they visit.

Orbits aren't stable.

If they were, worrying about "kessler syndrome" and "we cant pollute space!" would make more sense. But they're not. Stuff put in orbit will fall (or possible escape), and its a real job to find an orbit where that doesn't happen quickly.

Just like "COVID isn't smallpox".

Sure, but when two objects collide and transform into 1000 objects, a lot more than two of them will find semi-stable orbits. And by semi-stable I mean it doesn't have to be stable as like with satellite, it just have to stay up there for years to be a problem.

You'd have to have a lot of energy to knock something from VLEO to GEO.

I don't see it being a possibility, but I could be wrong, maybe someone smarter than me can do the math...

Space is vast, if you have debris with a lifespan of 5 years, you won't accumulate enough for it to be unavoidable, and the issue will literally solve itself.

It is _impossible_ to "knock" something from LEO to GEO. You can kick it to raise the apogee to GEO altitude, but the perigee will still be LEO. To change between two circular orbits, you need at least two impulses.

Reply on news.ycombinator.com