> SpaceX is deorbiting about one or two satellites daily, and that number is only going to grow.
> What that means for our planet isn't entirely clear
100 tons of meteors hit Earth every day[1], so it seems fairly clear the 800kg Starlink v2 mini satellites[2] don't amount to much. Maybe once a dozen providers are deorbiting a similar amount of mass daily, we might notice. But even then I'm not sure there would be any negative effects. This seems like clickbait scare mongering at the moment.
I think probably means SpaceX will need to keep sending rockets at rate of 1 or 2 satellites per day to replenish the infra. How much impact sending 800kg satellite into low orbit has?
At least 1.4% of Earth is aluminum. Meteors will have similar composition on average. Aluminum smelting likely vaporizes a much larger volume of material.
> ... the satellites are mostly aluminum; most meteoroids, in contrast, contain less than 1% Al by mass 25 . Thus, depending on the atmospheric residence time of material from reentered satellites, each mega-constellation will produce fine particulates that could greatly exceed natural forms of high-altitude atmospheric aluminum deposition, particularly if the full numbers of envisaged satellites are launched. Anthropogenic deposition of aluminum in the atmosphere has long been proposed in the context of geoengineering as a way to alter Earth’s albedo 26 . These proposals have been scientifically controversial and controlled experiments encountered substantial opposition 27 . Mega-constellations will begin this process as an uncontrolled experiment 28 .
> Concerns are mostly focused on aluminum, the most common component in satellites. If the disintegrated metal ends up as aluminum oxide or hydroxide, it can react with hydrogen chloride — the main reservoir of chlorine in the stratosphere, a hangover from the days of chlorofluorocarbons — to produce aluminum chloride. Hydrogen chloride is a relatively safe repository for chlorine, but aluminum chloride is easily split apart by light, freeing the chlorine to destroy ozone. Metal aerosols could also seed the creation of more polar stratospheric clouds, which catalyze reactions that liberate destructive forms of chlorine. “One can speculate, but without critical laboratory measurements of the chemistry, it’s very hard to know [the effects],” says John Plane, an atmospheric chemist at the University of Leeds. ... “You have to wonder whether [SpaceX] is creating a major problem 30 years from now,” Lionnet says.
timschmidt 2 days ago [-]
It's tough to find figures, but the amount of aluminum lost during smelting not accounted for in dross is as much as half a percent. World smelting capacity is 113 million tons per year. Which maths to as much as 565,000 tons of vaporized aluminum per year.
You're right that it's released into the lower atmosphere, though I'm sure smoke stacks loft that significantly in many cases. And it's difficult for me to believe that a few hundred kg per day, even if all of it ended up in the upper atmosphere, is anything more than a blip in comparison to what lofts up from industry.
The difference would have to be many thousands of times worse for upper atmosphere releases for it to even register.
eesmith 2 days ago [-]
> though I'm sure smoke stacks loft that significantly in many cases
It must be nice believing that your personal views are always correct.
To know that those geoengineers who want to disperse aluminum oxide to reduce the Earth's albedo clearly don't know how insignificant those aircraft deployed aerosols are compared to the byproducts of aluminum smelting.
To understand that conclusions like 'We find that the population of reentering satellites in 2022 caused a 29.5% increase of aluminum in the atmosphere above the natural level, resulting in around 17 metric tons of aluminum oxides injected into the mesosphere' can be ignored because 17 metric tons should be a blip compared to what lofts up from industry. (Quoting https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.102... )
That statements like "The natural entry of aluminum (Al) into Earth's atmosphere, primarily from meteoroids, is estimated at 141.1 metric tons (Mg) per year" is a deliberate obfuscation because it doesn't include antropogenic ground contributions. (Quoting https://www.viasat.com/content/dam/us-site/corporate/documen... )
> It must be nice believing that your personal views are always correct.
Well that's needlessly confrontational.
> That statements like "The natural entry of aluminum (Al) into Earth's atmosphere, primarily from meteoroids, is estimated at 141.1 metric tons (Mg) per year" is a deliberate obfuscation because it doesn't include antropogenic ground contributions.
Completely baffled as to who said this, and who you're accusing of deliberate obfuscation. The quote certainly wasn't pulled from any of my comments.
And you seem to have assumed a position here which I haven't taken. I have made no statements positive or negative about whether or not aluminum aerosols are harmful. Only that industry dwarfs satellite re-entry. And only after looking up stats.
I hope you're able to have a less angry day! Maybe take a walk?
eesmith 1 days ago [-]
> Completely baffled as to who said this
Follow the URL after "Quoting", on the line immediately following what you quoted. I gave URLs so you could read what actual experts are saying and doing.
> Only that industry dwarfs satellite re-entry.
You have made a hand-wavy gut-feeling conjecture about the amount of human-produced ground sources of aluminum in the upper atmosphere. You have given no stats.
I have linked to several papers and articles by people whose research (scientific and journalistic) say that, yes, the demise of megaconstellation satellites will significantly increase the percentage of aluminum in the upper atmosphere, with potentially negative effects like thinning the ozone layer.
Your belief about ground sources necessarily implies you believe all those researchers must be wrong.
DemocracyFTW2 1 days ago [-]
> Well that's needlessly confrontational.
you're the one who said "scaremongering".
SeanAnderson 2 days ago [-]
I had no idea 100 tons of external material was entering our atmosphere each day. Fascinating.
timschmidt 2 days ago [-]
An additional tidbit: this is not enough mass to offset the amount of helium and hydrogen which escapes Earth's atmosphere daily. Earth is on net losing mass. Eventually, Earth will lose all the hydrogen locked in it's oceans via this process. Not sure if that's destined to happen before or after we're engulfed by the expanding sun though.
khuey 2 days ago [-]
At the current rate of loss Earth has 150 billion years worth of hydrogen.
rkomorn 2 days ago [-]
Well that's bad news for all the infrastructure projects in my current city and country. They're gonna run out of hydrogen before our subway extension is finished.
thayne 2 days ago [-]
The composition is different though. In particular, these satellites probably have more heavy elements for things like batteries and electronics
andsoitis 2 days ago [-]
Meteors contain various heavy metals, primarily iron and nickel, which form metallic cores of asteroids and make up the bulk of many meteorites.
They also contain other siderophilic metals, including cobalt, chromium, gold, platinum, iridium, and tungsten. The high concentration of these metals, especially precious metals like gold and platinum, is due to their affinity for sinking to the core of early planets and asteroids, which are remnants of the primordial solar system.
timschmidt 2 days ago [-]
Further, satellites like Starlink's are engineered to burn up on re-entry. Meaning that they are manufactured of materials known to combust at re-entry velocities in thicknesses and shapes appropriate to that end.
eesmith 2 days ago [-]
One key difference is the satellites have a lot of aluminum - a light element - while meteors do not.
Estimates I've seen are that the amount of Al in the upper atmosphere will be dominated by satellite demise. And we don't know how that will affect things.
The history of CFC and the ozone layer suggests caution.
goopypoop 2 days ago [-]
> The typical meteor is produced by a particle with a mass of less than 1 gram—no larger than a pea
> The total mass of meteoric material entering Earth’s atmosphere is estimated to be about 100 tons per day
timschmidt 2 days ago [-]
... yes? Does the mass of individual meteors or satellites matter if they both burn up on [re]entry?
On average, something like 17 meteors large enough to strike the ground hit earth daily.
> The current strategy to de-orbit Starlink satellites, which operate in a low orbit below 600 kilometers, is to use the satellites' thrusters to move them to such a low orbit that they eventually catch drag in the atmosphere and burn up in what McDowell calls an "uncontrolled but assisted" reentry.
This is misleading, they're already in a very low orbit and would deorbit on their own in a just few years. They can manoeuver to explicitly deorbit on command, but they need active stationkeeping to stay up there for extended periods.
taneq 2 days ago [-]
Yeah, I thought this was a 'feature' (basically a hedge against them contributing to Kessler syndrome).
Gathering6678 2 days ago [-]
I wonder if there's a comparison between level of (a) pollution from satellites burning, and (b) pollution from other sources. If (a) is only a tiny amount compared to (b), I think this is not a significant issue.
stephc_int13 2 days ago [-]
I think the question to ask would be about the cost of maintaining that fleet.
Cost of building + launch, per satellite, any ideas?
How much is Elon _actually_ burning here? Is Starlink going to have a positive ROI at some point?
blargthorwars 2 days ago [-]
Starlink is crazy profitable. Source: Son has SpaceX stock and sees the audited financial reports in a locked room in Redmond.
saltyoldman 2 days ago [-]
Simplistically this is likely very true, if they have only 10m customers, that's like 12 billion a year. They can easily launch 12 times a year with 60 per launch, that's 720 replacements a year. Each launch is about 15m, so just replacing them each month they are spending 15m out of the 1b profit. Not bad.
And that's if they only have 10m customers - which I suspect is a lot more considering it's a worldwide service.
kaonwarb 2 days ago [-]
I was disappointed to learn approximately nothing from this article about why this matters.
mgoetzke 2 days ago [-]
It matters because it helps the "Elon Bad" storyline, that seems to be the connecting thread between all these "reports" whether about SpaceX or Tesla by some news outlets which dont even do the due diligence of putting the stories into any kind of perspective or try to find out if the implied premise of the headline is true or should even matter to the casual reader.
DemocracyFTW2 1 days ago [-]
At this point deorbiting satellites is rather on the light side of whatever Musk is doing and saying these days, don't you think?
wmf 2 days ago [-]
Based on the previous discussion, it releases pollution that may or may not matter.
SapporoChris 2 days ago [-]
I found this one weird trick. I select key words in an article and use an internet search to answer probing questions like 'why this matters'.
For example: Near the top of the article is the sentence: "Kessler syndrome is bad; atmospheric incineration may be worse, says astrophysicist Jonathan McDowell"
this has nothing to do with kessler syndrome. If anything, it's the opposite: satellites that are low in orbit deorbiting naturally. The article fails to explain why deorbiting sattelites at this frequency is bad, it just loosely suggests it with nothing to back up the claim.
The earth's atmosphere is pretty big, and sattelites are just made out of aluminum and crap. I don't think it is a big deal.
I could search this topic on google scholar for hours, but I can already tell the result is that I would probably find nothing of substance.
kataklasm 2 days ago [-]
When have we given up on expecting journalists to do their jobs and write articles worthy of being read and containing actual information? If I wanted to read blubberish I'd go read some AI slop but if an article is written by a human I have some base expectation of it providing a modicum of value to me. Even more so if it reaches the HN frontpage.
> What that means for our planet isn't entirely clear
100 tons of meteors hit Earth every day[1], so it seems fairly clear the 800kg Starlink v2 mini satellites[2] don't amount to much. Maybe once a dozen providers are deorbiting a similar amount of mass daily, we might notice. But even then I'm not sure there would be any negative effects. This seems like clickbait scare mongering at the moment.
1: https://pressbooks.online.ucf.edu/astronomybc/chapter/14-1-m...
2: https://dishycentral.com/how-big-are-starlink-satellites
[1] https://en.wikipedia.org/wiki/Cosmic_dust
[2] https://www.sciencedirect.com/science/article/pii/S0012821X2...
(in batches, obviously)
> ... the satellites are mostly aluminum; most meteoroids, in contrast, contain less than 1% Al by mass 25 . Thus, depending on the atmospheric residence time of material from reentered satellites, each mega-constellation will produce fine particulates that could greatly exceed natural forms of high-altitude atmospheric aluminum deposition, particularly if the full numbers of envisaged satellites are launched. Anthropogenic deposition of aluminum in the atmosphere has long been proposed in the context of geoengineering as a way to alter Earth’s albedo 26 . These proposals have been scientifically controversial and controlled experiments encountered substantial opposition 27 . Mega-constellations will begin this process as an uncontrolled experiment 28 .
Or from https://www.science.org/doi/pdf/10.1126/science.adr9689
> Concerns are mostly focused on aluminum, the most common component in satellites. If the disintegrated metal ends up as aluminum oxide or hydroxide, it can react with hydrogen chloride — the main reservoir of chlorine in the stratosphere, a hangover from the days of chlorofluorocarbons — to produce aluminum chloride. Hydrogen chloride is a relatively safe repository for chlorine, but aluminum chloride is easily split apart by light, freeing the chlorine to destroy ozone. Metal aerosols could also seed the creation of more polar stratospheric clouds, which catalyze reactions that liberate destructive forms of chlorine. “One can speculate, but without critical laboratory measurements of the chemistry, it’s very hard to know [the effects],” says John Plane, an atmospheric chemist at the University of Leeds. ... “You have to wonder whether [SpaceX] is creating a major problem 30 years from now,” Lionnet says.
You're right that it's released into the lower atmosphere, though I'm sure smoke stacks loft that significantly in many cases. And it's difficult for me to believe that a few hundred kg per day, even if all of it ended up in the upper atmosphere, is anything more than a blip in comparison to what lofts up from industry.
The difference would have to be many thousands of times worse for upper atmosphere releases for it to even register.
It must be nice believing that your personal views are always correct.
To know that those geoengineers who want to disperse aluminum oxide to reduce the Earth's albedo clearly don't know how insignificant those aircraft deployed aerosols are compared to the byproducts of aluminum smelting.
To understand that conclusions like 'We find that the population of reentering satellites in 2022 caused a 29.5% increase of aluminum in the atmosphere above the natural level, resulting in around 17 metric tons of aluminum oxides injected into the mesosphere' can be ignored because 17 metric tons should be a blip compared to what lofts up from industry. (Quoting https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.102... )
That statements like "The natural entry of aluminum (Al) into Earth's atmosphere, primarily from meteoroids, is estimated at 141.1 metric tons (Mg) per year" is a deliberate obfuscation because it doesn't include antropogenic ground contributions. (Quoting https://www.viasat.com/content/dam/us-site/corporate/documen... )
That people looking into wood-composite alternatives to aluminum, due to concerns about "increased metallic aerosols in the stratosphere" (https://conference.sdo.esoc.esa.int/proceedings/sdc9/paper/8... ) are wasting their time.
Well that's needlessly confrontational.
> That statements like "The natural entry of aluminum (Al) into Earth's atmosphere, primarily from meteoroids, is estimated at 141.1 metric tons (Mg) per year" is a deliberate obfuscation because it doesn't include antropogenic ground contributions.
Completely baffled as to who said this, and who you're accusing of deliberate obfuscation. The quote certainly wasn't pulled from any of my comments.
> That people looking into wood-composite alternatives to aluminum, due to concerns about "increased metallic aerosols in the stratosphere" (https://conference.sdo.esoc.esa.int/proceedings/sdc9/paper/8... ) are wasting their time.
And you seem to have assumed a position here which I haven't taken. I have made no statements positive or negative about whether or not aluminum aerosols are harmful. Only that industry dwarfs satellite re-entry. And only after looking up stats.
I hope you're able to have a less angry day! Maybe take a walk?
Follow the URL after "Quoting", on the line immediately following what you quoted. I gave URLs so you could read what actual experts are saying and doing.
> Only that industry dwarfs satellite re-entry.
You have made a hand-wavy gut-feeling conjecture about the amount of human-produced ground sources of aluminum in the upper atmosphere. You have given no stats.
I have linked to several papers and articles by people whose research (scientific and journalistic) say that, yes, the demise of megaconstellation satellites will significantly increase the percentage of aluminum in the upper atmosphere, with potentially negative effects like thinning the ozone layer.
Your belief about ground sources necessarily implies you believe all those researchers must be wrong.
you're the one who said "scaremongering".
They also contain other siderophilic metals, including cobalt, chromium, gold, platinum, iridium, and tungsten. The high concentration of these metals, especially precious metals like gold and platinum, is due to their affinity for sinking to the core of early planets and asteroids, which are remnants of the primordial solar system.
Estimates I've seen are that the amount of Al in the upper atmosphere will be dominated by satellite demise. And we don't know how that will affect things.
The history of CFC and the ozone layer suggests caution.
> The total mass of meteoric material entering Earth’s atmosphere is estimated to be about 100 tons per day
On average, something like 17 meteors large enough to strike the ground hit earth daily.
One to two Starlink satellites are falling back to Earth each day - https://news.ycombinator.com/item?id=45493143 - 6 Oct 2025 (336 comments)
This is misleading, they're already in a very low orbit and would deorbit on their own in a just few years. They can manoeuver to explicitly deorbit on command, but they need active stationkeeping to stay up there for extended periods.
Cost of building + launch, per satellite, any ideas?
How much is Elon _actually_ burning here? Is Starlink going to have a positive ROI at some point?
And that's if they only have 10m customers - which I suspect is a lot more considering it's a worldwide service.
For example: Near the top of the article is the sentence: "Kessler syndrome is bad; atmospheric incineration may be worse, says astrophysicist Jonathan McDowell"
So, I searched for "kessler syndrome". Here's the hyperlink for reference: https://duckduckgo.com/?t=ffab&q=kessler+syndrome&ia=web
Now here is the cool part. I found a Wikipedia article about "kessler syndrome" https://en.wikipedia.org/wiki/Kessler_syndrome and it explained why this matters!
The earth's atmosphere is pretty big, and sattelites are just made out of aluminum and crap. I don't think it is a big deal.
I could search this topic on google scholar for hours, but I can already tell the result is that I would probably find nothing of substance.
edit: removed my own snark. sorry for that.