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New Calculation Finds we are close to the Kessler Syndrome [video]

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Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#121

Earlier quoted context omitted.

No. The space junk at a given orbit makes it unviable to put more satellites in that orbit, but launching beyond that orbit is still viable.

How can you get past that orbit if there is all this junk destroying your rockets????

It really depends on how much junk actually is there and in what orbits; especially at 500 km up, space is big. The surface area of the earth is 510.100.000 square kilometers, at 500 kilometers the 'surface area' is a multiple of that (I can't math), surely there's enough gaps or lower-density areas at that height even if there was a catastrophic Kessler Syndrome event.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#122
post #65

Earlier quoted context omitted.

I'd consider it much less likely than e.g. nuclear or maybe chemical/biological warfare. 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…

> if even achievable with current technology 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.

I'd say intentionally destroying space assets etc should be considered an act of war (compare attacking another nation's ship in international waters), NK wouldn't have a chance and they could be put into space lockdown where any launches are intercepted.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#123
post #87

Earlier quoted context omitted.

> couldn't you just send a bunch of fortified rockets that absorb the debris during a collision but don't emit anything. "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 r…

A large mass of Whipple shields. The "clearing a path" idea is inane, but we do know how to absorb hypervelocity debris impacts while generating a net negative amount of debris.

Whipple shields fragment, don't they? They slow stuff down enough to not be a hazard to the thing being shielded, but if the goal is mess-reduction I don't see how that will help?

https://www.researchgate.net/figure/Whipple-shield-concept_f...

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#124

Earlier quoted context omitted.

No. The space junk at a given orbit makes it unviable to put more satellites in that orbit, but launching beyond that orbit is still viable.

How can you get past that orbit if there is all this junk destroying your rockets????

integrate risk over time. if you have a high target orbit outside the "kessler belt" then you don't spend much time going through it. though this requires a fairly direct orbital insertion. slow orbit raising would have a higher risk, but even that would still be lower than for any satellite intended to operate for years and decades in an affected orbit.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#125

Earlier quoted context omitted.

How can you get past that orbit if there is all this junk destroying your rockets????

It really depends on how much junk actually is there and in what orbits; especially at 500 km up, space is big. The surface area of the earth is 510.100.000 square kilometers, at 500 kilometers the 'surface area' is a multiple of that (I can't math), surely there's enough gaps or lower-density areas at that height even if there was a catastrophic Kessler Syndrome event.

The surface area at 500 km is 1.16 of the Earth surface area.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#126

Earlier quoted context omitted.

I think OP is suggesting US concede to sharing 500km orbits that SpaceX has disproportionately squatted rights to, since current international law is first come first serve. Where concede is to rejigger international law to increase density of 500km so others wouldn't have to go higher, i.e. PRC mega constellations going ~800 because ~500 mostly taken. Or in ops suggestion, free for all. This is more costly for US si…

Others would use theblower orbits - but it is just not viable for them, as their rockets suck (eq. are not reusable) and thus they need to put their few expensive satellites with meager propulsion capabilities higher to last longer. Not to mention spot beams being wide enough with so few satellites.

>others would use theblower orbits

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.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#127
post #8

The current trajectory is that SpaceX proved the commercial and military viability of an LEO megaconstellation, repeatedly lowering their target altitudes and raising their satellite count because of debris and cell size concerns... 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 t…

> We need viable treaties limiting development beyond 400 or 500km and we need them ten years ago.

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.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#128

Earlier quoted context omitted.

I think OP is suggesting US concede to sharing 500km orbits that SpaceX has disproportionately squatted rights to, since current international law is first come first serve. Where concede is to rejigger international law to increase density of 500km so others wouldn't have to go higher, i.e. PRC mega constellations going ~800 because ~500 mostly taken. Or in ops suggestion, free for all. This is more costly for US si…

No; rather, that commenter's argument was "The most tempting orbits are the ones in upper LEO that permit them to launch fewer satellites." Higher altitude => wider coverage => fewer satellites

We're talking about megaconstellations for communications, you want lower for latency, stronger signal (denser/less distance for beamforming) for better data through put -> less satellites for more coverage, and costs is cheaper since less energy. Realistically starlink has combination of 340km-1200km satellites working together, but the critical point is SpaceX reserved a lot of the sub 500km orbit slots with ITU (UN agency who manages orbits), so PRC competitors have no space real estate to try to throw up another mega constellation that can mimic spaceX economics due to location, location, location. Hence PRC registering Thousand Sails at 800km, Guowang at 500km-1200km orbits, etc, which according to OP is exponentially bad for Kessler (I have no idea). So either ITU opens much more 400km slots, or all the megaconstellations going forward going to satuate >500km LEO. Part of the reason PRC rushed to announce their megaconstellations before they even had reusable was to reserve the next closest available orbit slots that they can.

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#129
post #8

The current trajectory is that SpaceX proved the commercial and military viability of an LEO megaconstellation, repeatedly lowering their target altitudes and raising their satellite count because of debris and cell size concerns... 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 t…

[deleted]

Re: New Calculation Finds we are close to the Kessler Syndrome [video]

#130

Earlier quoted context omitted.

> if even achievable with current technology 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.

I'd say intentionally destroying space assets etc should be considered an act of war (compare attacking another nation's ship in international waters), NK wouldn't have a chance and they could be put into space lockdown where any launches are intercepted.

Good luck dragging people into war over space trash that doesn't even benefit most peoples' lives in any material sense.
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