Plasma Tunnels Reveal How Dying Satellites Fall to Earth | Hacker News Reader

Plasma Tunnels Reveal How Dying Satellites Fall to Earth

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66 pointsmarc__138 comments

Satellites have many chlorinated and florinated chemicals, so being vaporized means introducing large volumes to the upper atmosphere where they can catalyze the destruction of ozone molecules. I'd be interested how the volume compares to other sources of atmospheric halogens. They could hardly match the quantity of refrigerant gases released, but being deposited directly in the upper atmosphere may make them more potent.

Good catch. I doubt it's even a rounding error right now, but with the space market undergoing a rather rapid growth (good thing!), it's a good time to start tracking this and hopefully address before it turns into a problem.

>hopefully address before it turns into a problem.

Ron Howard's voice "They didn't."

But in all seriousness, there will be zero stomach for limiting launches for the ozone layer. I'm calling it now. Group 1 won't believe it's a problem. Group 2 will say it's just lefty elitists trying to ruin the economy. Group 3 will say there's no such thing as satellites.

Check back in 40 years. I bet I'm right.

New Zealand will be back to the top of the skin cancer list. We'll be getting the 10 minute exposure sunburns in winter too!

Well… did they or didn’t they?

It's funny, one of the benchmarks I've used when trying to decide when things went off the rails was that banning CFCs was a relatively uncontroversial thing in the 1990s. Now, I agree with your pessimism.

The same rails that failed to ban coal power in the 1990s? That controversially both did and didn't ban nuclear power? And what about satanic rituals? People rightly disagree on decisions that have unknown consequences in either direction. It's not off the rails, it's just different from your personal opinion.

I strongly recommend Merchants of Doubt [1], it's fairly clear what happened: learning from the "mistake" of the tobacco industry financing research, the oil industry understood that producing their own honest science was a liability, not a defense. The only way to avoid being held accountable for climate change was to sneakily but relentlessly attack science to discredit it. Keep the controversy alive. Seed doubt in the mind of people.

Not just regarding climate, virtually all of science. Science itself is the target. The overlap between climate change denial and COVID denial (for instance) is documented: same think tanks, same commentators. [2]

[1] https://en.wikipedia.org/wiki/Merchants_of_Doubt

[2] https://www.desmog.com/covidenial-executive-summary/

You seem to assume it'll be a problem. My bet is group 1 is right and everyone agrees with them except a few nutters on the internet who like to fantasize about environmental damage from everything good.

I'm moving my timeline up from 40 years now.

During the peak something like a million metric tons of refrigerants were making their way into the atmosphere yearly.

Maybe one or two tons of vaguely related chemicals are making their way into the atmosphere in the form of deorbited satellite materials and there's no 1:1 guarantee they're having anything like similar effects.

So it's a number measured in parts per million of the problem we were having in the 80s.

What would be the number of reentries in the near future?

5-20 satellites daily?

At first glance, it seems negligible.

On the hand, given the intentional nature if disposable low-orbit, 20 more than ideal.

SpaceX wants their Starlink constellation to crack 100,000, and there are plenty of competitors lining up who will surely want to have "the biggest and the best" at some point. None of those sats stay up terribly long, so you'll have a constant cadence of launches and reentries, both of which are a risk for their impact on the climate system, atmosphere, etc.

A largely unstudied risk, and once which will almost certainly be strenuously ignored for as long as possible.

100 tons of whatever enter the Earth every single day. Are you freaking out about that?

Those are rocks, which are not made from the same stuff as satellites. (Also, the article says it's 44 tons, and other sources suggest around 50 at most.) In any case, I don't think anyone here is "freaking out", I just think this issue merits investigation.

I’m not GP but your original comment did not come across as neutral

Why do you consider the ideal point for this question absolute 0 zero reentries rather than the minimal number of reentries that don’t cause damage to the atmosphere?

I presume dead orbiting satellites will become a source of valuable refined materials in orbit in not a particularly long time.

So do incinerating satellites create tunnels of conductive plasma through the atmosphere? Perhaps they are creating short circuits in the air. Could pieces of junk reaching the lower atmosphere cause lightning strikes by creating conductive paths? When I read the title about "plasma tunnels" that's what I thought the article was going to be about, not wind tunnels.

> However, the rapidly increasing numbers of launches to low Earth orbit now threaten to increase the levels of space junk reentering the atmosphere.

Isn't it not space junk if it is burning up in the atmosphere? Kinda conflating two different concerns here that are somewhat mutually exclusive.

It's space junk and then it enters the atmosphere and burns up, I don't think it's too hard to figure out.

If it turns out the junk truly disintegrates without any significant affect to the atmosphere then GP is saying that it’s not actually a problem and not actually “junk”. Space junk usually refers to stuff junking up things in the same way a rusted out sedan ruins a yard.

If the sedan disappeared it wouldn’t really be considered junk. If the sedan disappeared but left behind a puddle of poison the label would still apply.

Well it’s definitely junk or waste or garbage from the moment you are unable to use it or reclaim it. It so happens in the case of starlink satellites that we don’t have to burn that trash, it burns itself. If you want to say space junk is just the stuff stuck up there that’s fine, but there’s a short period of time where Starlink satellites are both in space and are junk.

The typical meaning of space junk is stuff orbiting around without the ability to control itself and without de-orbiting, therefore presenting a risk/nuisance to other things in orbit.

Is a Starlink sat that reaches EOL and sets itself on trajectory for rapid de-orbit ever junk by such a definition?

So... We still don't know if aluminum on satellites can be a problem or not.

Yes, it's nice that failed experiments get reported. But why another press article claiming the problem that this one research has been failing for a decade to show that exists?

100 tons of metal-based rock falls to earth daily from the solar system.

Waste of fucking money. The X that fall per year is nothing compared to the millions of tons of other pollution.

This kind of thinking is exactly what led to the ozone hole in the first place. Let's actually investigate our assumptions this time.

No, there was no a priori evidence when the big "fuss" around the ozone happened. I happen to agree with it. Why spend millions of choice your choice of first world currency to worry about 0.000000000001% of the pollution the earth, our earth is facing.

Perhaps you're not living in the same world as I, but I've both experienced the wettest and driest year on record.

Exactly.. If I have only few hundreds car in the world, will that lead to air pollution ?

Science give us knowledge rooted in hard evidence, science give us models that can be reused as is or used to refine other models. The article mentions how hard it is to monitor atmosphere at 60-80km because it is too high for weather balloons and too low for satellites, now they are doing something about it.

Money spent on science is not a waste of money, even if science come with a negative answer. If you want to find ways to slash wasteful spending, I'd urge you to look at wars: these are really eat a lot of money and give nothing back.

Nice strawman. I did not say spending money on science is a waste of money. Spending a bunch of money which is quantifiably not an issue.

It is the same daft shit as trying to colonise Mars. Fuck off. If you cannot tame earth, its deserts, its extremes, why, why?!

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

> I did not say spending money on science is a waste of money.

This research is science, you've said it is waste of money,... well, I see now, that it is not the same as "science is waste of money", you argue that this particular research project is a waste of money?

But my objections still stand: the research allow us to get new data, and it is pretty interesting data. There is a lot of talk of going hypersonic for various reasons, and there are issues that no one knows how exactly things break up when burning at hypersonic speeds. So there is a gap in our knowledge and this "plasma tunnel" can help to fill it. Why do you think it is a waste of money?

> It is the same daft shit as trying to colonise Mars.

I don't see any similarities. To colonize Mars is a practical endeavor, and if we wanted to justify it we would refer to some practical benefits we could reap from colonizing. The research of how things burn in atmosphere is a theoretical research, the goal is to gain new knowledge. To argue that it is a waste of money, we need to show that there is no new knowledge to look for.

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