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BeerPoweredNonsense t1_jay4bff wrote

Reply to comment by PEVEI in Half of all active satellites are now from SpaceX. Here’s why that may be a problem by ye_olde_astronaut

>active satellites

The main issues with "too much shit in orbit" are, I believe: 1. Risk of Kessler Syndrome 2. Impact on astronomy.

In both the above, a dead satellite is as much of a risk as an active satellite. More so in fact - an active satellite can be ordered to dodge an imminent collision.

The US are tracking IIRC 13,000 objects in orbit. To focus only on active satellites is unscientific.

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PEVEI t1_jay58f4 wrote

Virtually no one on this sub I've met understands Kessler Syndrome, nor do they understand why it isn't a meaningful issue for the sort of orbits we're talking about. Impact on astronomy is a big issue, although it appears that for interesting reasons, many here are unmoved by that.

I would add that the "13,000 objects in orbit" is both a lowball (the estimate from NASA is well over 20k) and not referring mostly to inactive satellites. In fact that number refers to anything 10cm and over, and the majority is junk. The number of inactive sats is much lower, a fraction of that number, about 7500 according to the article we're responding to above. SpaceX accounts for half of that number.

As far as dead sats, they're in a different stat which includes spent rocket stages, and that number is about 3000. There are in fact more SpaceX sats in LEO than dead sats and rocket stages from all other sources in history.

With more launched every year.

Edit: Virtually none of that space junk making up the 25K+ number is visible to the naked eye, nor does it have a material impact on Earth-based astronomy.

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simcoder t1_jay67su wrote

> Kessler Syndrome

Debris cascades are a very real issue though.

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PEVEI t1_jaya2sl wrote

It's real, but incredibly overblown in the popular imagination, especially for LEO.

https://aquarid.physics.uwo.ca/kessler/Kessler%20Syndrome-AAS%20Paper.pdf

The reality is that it's going to be a source of debris going forward, but it's incredibly unlikely to become the sci-fi nightmare people mean when they refer to it. In reality it's just another added cost of doing business, barring some sort of extreme event such a war in orbit, or suicidal nuclear strikes.

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simcoder t1_jayapsk wrote

A XX,000 satellite constellation going full debris cascade is going to leave a mark on LEO for quite a while. And that debris will have to traverse the orbits of the space stations and Hubble and who knows what else as it deorbits.

It's pretty common for the SpaceX superfan to completely disregard the impacts of such a thing. I'm not sure how they do it but they seem to be able to filter out any and all bad outcomes when their favorite corporation is involved.

I guess it's their super power.

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RavenchildishGambino t1_jaz83hc wrote

Not in LEO. Because atmosphere and gravity exist.

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simcoder t1_jaz8r2i wrote

Sure they are.

Put enough stuff up there and eventually you'll get a cascade. Spread that out amongst various operators, both friendly and unfriendly, and you won't even need as much stuff to get to that point.

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RavenchildishGambino t1_jaz9vj8 wrote

Yes. And how long will this cascade last?

5-10 years?

Chip in some maths here to prove your point.

A Starlink satellite should naturally fall out of the sky in 5ish years.

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simcoder t1_jazcq1a wrote

Both space stations and Hubble are in the debris path to deorbit. As are a lot of other things that people would prefer not get shredded or have to burn all their fuel dodging broken dreams.

So, a lot can happen in 5 or 10 years. Or however long it takes for the full evolution to occur. And the geopolitical ramifications could cause all sorts of strife here on the ground above and beyond the collateral damage in orbit.

To dismiss the potential consequences of a worst case scenario would be very, very foolish.

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BeerPoweredNonsense t1_jazqav9 wrote

No one's dismissing it - in particular, the US authorities forced several adaptations to Starlink in order to reduce the risks of mega-constellations e.g. insisting that satellites fully burn-up on re-entry in order to minimise risks to the v1.0 humans on the ground.

It is normal to be wary, and to insist on proceeding with caution. However many of the anti-Starlink posters are just hiding their hate-boner for Elon under a pseudo-scientific veneer. E.g. mention Starlink on Reddit and you're guaranteed "Kessler Syndrome!" and "Astronomy!" replies. But posts about the other mega-constellations currently in deployment do not seem to attract the same "science-based concern" :shrugs:

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simcoder t1_jb178i8 wrote

>No one's dismissing it

Yes...they are.

In fact the other guy just said that whatever collateral damage happens is just the sad wreckage we'll need to leave in our wake to move up the technological ladder.

It's pretty scary to be honest. All the things that the SpaceX fanbase is willing to sacrifice to achieve Elon's goals.

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RavenchildishGambino t1_jb0wbhh wrote

The answer is to not do anything and progress.

The first time the USA made a nuclear reactor they almost melted it down.

The first time they set of a nuclear bomb they weren’t 100% sure they wouldn’t light the atmosphere on fire.

The ISS is old and near end of life.

Hubble is beyond its End of Mission date, though still useful.

5-10 years of no progress would be unfortunate, but there was more than 10 years of America unable to launch their astronauts to space. It’s not that long.

That’s why these things should be tried, but tried in LEO, where the mess will clean itself up within a generation.

Space is huge, and while I think Elon is a turd burger of a human, having 100,000 large-ish objects up in the sky (which is a huge place) can be handled with our current level of technology.

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simcoder t1_jb16mkh wrote

Hmmm. Well I think you might need to do a better job convincing the Chinese that potentially sacrificing their station is just a necessary step down the road of progress.

I don't think they are going to buy your theory.

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RavenchildishGambino t1_jb3lpyy wrote

I’m not going to convince the Chinese of anything.

They literally don’t care. They don’t even make sure their Long March boosters won’t deorbit and hit land in a populated area.

Since they show they don’t care, why would your argument about the Chinese be something I take even remotely seriously?

Hey China!

I DONT GIVE AN EFF ABOUT YOUR STATION. LEARN TO CONTROL YOUR BOOSTERS BEFORE WE TAKE YOU SERIOUSLY.

https://www.cnn.com/2022/11/04/world/china-rocket-booster-long-march-reentry-scn/index.html

Also, let’s talk about human rights when you have a moment.

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simcoder t1_jb3r7v1 wrote

I guess the point is that, regardless of whether you give a shit or not about collateral damage, the world likely will give a shit.

Mega-constellation debris cascades are a serious concern and shouldn't be dismissed. To do so would be extremely naive and/or foolish.

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RavenchildishGambino t1_jb3rhuw wrote

Yeah. LEO orbit is huge. We’ll be good. Cheer up.

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simcoder t1_jb3s341 wrote

I'm just saying that to blithely disregard the risks involved with these things is kind of foolish.

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RavenchildishGambino t1_jb3s8f8 wrote

These folks are highly educated engineers and professionals. The only person taking it lightly is you, and your hyperbole.

I’m not buying it.

Go rant somewhere else please.

Have a great day, but kindly move on with this fear mongering.

This conversation is foolish.

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JohnathonLongbottom t1_jaya11b wrote

I've had people tell me that Kessler syndrome is a non issue and will never happen. Hilarious the hubris of some people

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Elon-Musk-Officiall t1_jay8ju1 wrote

It seems clear to me what kessler syndrome is and how it applies, from about 5 minutes of reading. Its a cascade that will cause material to spray into different orbits and at different speeds depending on mass. Thank you for the slight.

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RavenchildishGambino t1_jaz7ygi wrote

A LEO satellite is less risky for Kessler. All debris should deorbit in 10 years or less.

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