Hacker News Reader

Comment by acidburnNSA | Hacker News Reader

Agree with all of that, except the world war part. Satellites will definitely be fair game in world war 3... probably one of the first targets.

Ham radio will live on!

View on HN

I don't know – would we risk Kessler Syndrome for a war? Win a piece of land and doom humanity for a hundred years of regress in space? Maybe, probably can't be ruled out.

As for jamming, is it feasible or practical to jam very large parts of the world? I can't imagine it would be. It seems to me like jamming would probably be used for specific military purposes and people would be left alone to communicate with each other otherwise.

It's not that I'm saying this could not be done. It could. But this is not the most likely scenario in my head. The immense benefit to all humanity is a very likely scenario, in contrast.

LoRa is another equally exciting technology that has a lot of potential in all the spaces I mentioned. I just can't currently imagine a reason it would go mass-market.

Of course we would. And anyway the Starlink constellation is low enough that even destroying the whole constellation would have a minimal impact after a decade.

With how close to earth Starlink satellites fly, it won't take hundreds of years. Without the occasional boost back into orbit, it'll only take a couple of years for them to fall back to earth. Same with most spy satellites. We can do without space internet for a few decades if we blow up several of these constellations.

As for further-away satellites (Iridium etc.), that's a bigger risk, but there aren't that many that make sense to target in a war.

Energetic collisions can send debris on higher orbits with significant longer time to decays. It all depends on kinetic energy added

If pieces got bumped into a higher apogee wouldn't their orbit end up with a lower perigee as well? If so I think that might actually be better for deorbiting quickly

As long as it doesn't hit something while it's in apogee.

One collision might be barely statistically possible. Enough collisions to start Kessler takes a lot more than one.

Isn't it the Kessler Syndrome when the debris from the first collision creates the subsequent collisions?

Diffuse debris while at higher orbit can take out satellites in those higher orbits (like Iridium, Kuiper, etc..)

> it won't take hundreds of years

Maybe not for Starlink itself, but its debris may be eccentric enough to hit satellites in higher orbits, thus causing an upward cascade of collisions resulting in debris clouds that do have a real possibility of remaining in orbit for many times the debris of Starlink.

Eccentric orbits mean higher apogee but also lower perigee, which for something at Starlink altitude likely means perigee is below the Karman line. Which means they'd deorbit within 90 minutes. So they'd only have one chance to hit something in higher orbit. You won't get enough collisions to start Kessler.

Starlink operational orbits are generally >500KM high (original license "at 525, 530, and 535 km", -Wikipedia).

I think it is not unreasonable to expect any debris clouds from Starlink to impact orbits from 300km to 700km for many months, if not years. Even if the debris with highest eccentricity will quickly burn up in the upper atmosphere, there will likely remain a significant portion in orbits that are eccentric enough to be problematic for higher orbits for years, (slowly?) cascading the debris orbits upward. It doesn't have to happen immediately after impact, but kessler syndrome doesn't have to imply 100% guaranteed loss in a day either.

Debris has a much higher surface to mass ratio than satellites due to their smaller size and irregular shape. Therefore debris deorbits much quicker than satellites do.

300km orbit decays in about a month, so the risk is already reduced significantly.

And there's not much in the 500 - 700km range now. Kuiper will be there soon, but anybody that takes out Starlink is also going to take out Kuiper.

Precisely

The same type that risks a nuclear war would easily risk Kessler Syndrome.

And don't forget there are people who think their god would protect them.

> would we risk Kessler Syndrome for a war?

I mean, yes, absolutely! I wouldn't trust world leaders to understand Kessler syndrome, let alone care about it. If a world leader is comfortable killing hundreds of thousands of people to make their nation "safe", targeting civilian infrastructure, I have no doubt that they'd blow up some stuff in orbit.

To be clear, I don't want to risk it. I'd prefer we didn't live in such a warlike world. But the current world leaders are out here bombing nuclear plants and residential districts. A few satellites will feel very, very far away to them.

Yes. The military believes that our adversaries would attack their satellites. China, USA and India have demoed the capability to shoot satellites in non wartime, adding tons of debris.

LoRa will never take off since it doesn't have the bandwidth for wide usage. Short messages are the limit. It also can't replace this usage since there aren't nodes in the middle of the ocean. If anything, this will reduce the need for LoRa messaging.

There a plenty of men who would be content to be kings of the ashes;

Don't consider this from the perspective of a reasonable person - ask yourself: what would psychopaths do?

It’s less that and more just basic strategy.

Your enemy has sat communications. You don’t. Well, it’s unlikely you’re going to get sat communications - so what do you do?

It’s logical to take out enemy communications.

The other side of the coin is, the enemy with the satellite can try to offer you the use of them as well, so you wouldn’t feel the need to destroy them - but will they?

If I have a rocket/missile capable of reaching a communication satellite orbit... why don't I have sat communications?

International sanctions.

It's much easier to intercept than enter orbit. ASATs are 100 kg rockets.

Russia has risked Kessler syndrome for less with ASAT missiles

While I really really hope no one would be that stupid as to risk a Kessler syndrome... I think it's really likely in a very specific situation:

A non-space-dominant power (so not Russia/China/USA) gets into a tiff with someone using satellites. This player does have access to at least the vaguest concept of a ballistic missile. They take said missile and program it to fly into space (as most beyond the tactical level do), and detonate.

Nuclear or not, they don't even have to hit the satellite, they just have to throw up shrapnel. Hell, you can replace most of the explosive warhead with ball bearings. It may not immediately take down a specific satellite but it's almost assured to fuck space up.

And in case it's not obvious, this seems like a very North Korean type thing to do. Their missiles aren't terribly reliable or accurate (so far), but good enough to get into space and ruin everyones day for a very long time there after. They have, what, a single satellite? [1] when everyone else has hundreds? Why not level the playing field and assure no one can use any of them - given enough time.

I'd be willing to be its in someones MAD playbook as well. It only takes a few hundred nukes to effectively end all life on earth, permanently. There are still 5,000 plus in both Russia and the US's stockpile [2], not to mention China, France and the UK has a couple hundred each. What do you do with some of those few thousand extra nukes? Detonate them in air and orbit to take out your Doomsday planes [3] and any potential orbital capabilities - just in case you survive.

But honestly, the Kessler Syndrome wouldn't really be a concern at that point since everything, including the roaches, would be a radioactive pile of glass.

[1] https://www.reuters.com/technology/space/north-koreas-first-...

[2] https://fas.org/initiative/status-world-nuclear-forces/

[3] https://en.wikipedia.org/wiki/Doomsday_plane

>It only takes a few hundred nukes to effectively end all life on earth, permanently

Human civilization maybe, but "all life on earth" is a stretch

There's some life kilometers deep into the Earth, don't think it's possible to destroy that without deep-frying whole planet

By definition of going to war, they are willing to risk their very existence. Taking out satellites and making orbit entry fraught with hazards seems a very rational choice for many opponents on the world stage.

If the recent Middle East events have shown anything, nothing is off the table with a ww3 scenario.

Reply on news.ycombinator.com