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Earth Communications

Satellite 'Megaconstellations' May Jeopardize Recovery of Ozone Hole (phys.org) 90

An anonymous reader quotes a report from Phys.Org: When old satellites fall into Earth's atmosphere and burn up, they leave behind tiny particles of aluminum oxide, which eat away at Earth's protective ozone layer. A new study finds that these oxides have increased 8-fold between 2016 and 2022 and will continue to accumulate as the number of low-Earth-orbit satellites skyrockets. The 1987 Montreal Protocol successfully regulated ozone-damaging CFCs to protect the ozone layer, shrinking the ozone hole over Antarctica with recovery expected within fifty years. But the unanticipated growth of aluminum oxides may push pause on the ozone success story in decades to come. Of the 8,100 objects in low Earth orbit, 6,000 are Starlink satellites launched in the last few years. Demand for global internet coverage is driving a rapid ramp up of launches of small communication satellite swarms. SpaceX is the frontrunner in this enterprise, with permission to launch another 12,000 Starlink satellites and as many as 42,000 planned. Amazon and other companies around the globe are also planning constellations ranging from 3,000 to 13,000 satellites, the authors of the study said. Internet satellites in low Earth orbit are short-lived, at about five years. Companies must then launch replacement satellites to maintain internet service, continuing a cycle of planned obsolescence and unplanned pollution.

Aluminum oxides spark chemical reactions that destroy stratospheric ozone, which protects Earth from harmful UV radiation. The oxides don't react chemically with ozone molecules, instead triggering destructive reactions between ozone and chlorine that deplete the ozone layer. Because aluminum oxides are not consumed by these chemical reactions, they can continue to destroy molecule after molecule of ozone for decades as they drift down through the stratosphere. Yet little attention has yet been paid to pollutants formed when satellites fall into the upper atmosphere and burn. Earlier studies of satellite pollution largely focused on the consequences of propelling a launch vehicle into space, such as the release of rocket fuel. The new study, by a research team from the University of Southern California Viterbi School of Engineering, is the first realistic estimate of the extent of this long-lived pollution in the upper atmosphere, the authors said. [...]

In 2022, reentering satellites increased aluminum in the atmosphere by 29.5% over natural levels, the researchers found. The modeling showed that a typical 250-kilogram (550-pound) satellite with 30% of its mass being aluminum will generate about 30 kilograms (66 pounds) of aluminum oxide nanoparticles (1-100 nanometers in size) during its reentry plunge. Most of these particles are created in the mesosphere, 50-85 kilometers (30-50 miles) above Earth's surface. The team then calculated that based on particle size, it would take up to 30 years for the aluminum oxides to drift down to stratospheric altitudes, where 90% of Earth's ozone is located. The researchers estimated that by the time the currently planned satellite constellations are complete, every year, 912 metric tons of aluminum (1,005 U.S. tons) will fall to Earth. That will release around 360 metric tons (397 U.S. tons) of aluminum oxides per year to the atmosphere, an increase of 646% over natural levels.
The study is published in the journal Geophysical Research Letters.
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Satellite 'Megaconstellations' May Jeopardize Recovery of Ozone Hole

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  • So, I read the paper (Score:5, Interesting)

    by Rei ( 128717 ) on Wednesday June 19, 2024 @05:39AM (#64560303) Homepage

    And while there seems to be a lot of great effort put into the breakup modeling, there's basically no effort put into discussing what a 646%-increase over natural levels means in terms of how much ozone depletion could be expected. Many things deplete ozone, and alumium oxide is not one thing that even makes the list. How does this amount compare to, say, CFCs? HCFCs? Halons? Methyl chloroform? Hydrogen? Nitrous oxide? Chlorine and bromine from volcanic eruptions and marine sources? Solar activity? Wildfires? Exactly what does a 646% increase in alumium oxide mean for ozone depletion? They sadly don't go into that.

    Note that the paper focuses solely on alumium entering Earth, while alumium is a lesser component of most natural mass influx, something like 3% or so. Most of the influx is oxygen, followed by silicon, magnesium, iron and calcium. So even the full scales of planned megaconstellations lead to relatively small increases in total influx. Still, it's very good that there's modeling work underway on this - we've certainly learned not to underestimate our ability to alter the planet by accident. And if Starship gets even close to its design launch costs, people's plans for LEO might get much, much bigger.

    Honestly, I rather expect that SpaceX, once Starship gets up and running reliably, will do "Round #2" of creating business for itself (ala Starlink) by building a (potentially toroidal) space habitat made out of numerous identical segments sized for Starship's payload bay and linked end-to-end in orbit. I did the math on it a while back and real estate inside would be priced quite affordably if Starship's launch costs are as-planned. Like, a "low-end" segment potentially at "downtown apartment in a large city" per-square-meter costs. So even if cost inflation is by an order of magnitude or two, I'm sure they could occupy it.

    That's a roundabout way of saying: people's plans for Low Earth Orbit may grow significantly, and so influx plans may as well.

    • by Viol8 ( 599362 )

      "I'm sure they could occupy it."

      Maybe, maybe not. So far space stations have been little more than metaphorical flag planting by the countries concerned though they justify them with some frankly risible "science". There's zero political capital to be gained for country to rent some habitat from Musk and its unlikely many commercial ventures would want or need it either unless some amazing new tech comes along that can only be developed in microgravity.

      • by Rei ( 128717 )

        What do "countries" have to do with anything? I'm talking individuals. People who want to live in space (permanently, temporarily, or just as a vacation). 80 million people in the world have a net worth of ~$3M or greater. It doesn't take a very large percent to want to spend time in space to fully occupy a several-thousand-person space station.

        • by Rei ( 128717 )

          Just to expand a bit more on what $10/kg to LEO enables:

          * NASA's plans for a 74-passenger variant of the Space Shuttle imply 325kg mass to orbit per passenger. Going with that ratio, $10/kg implies (before profit) a ticket price of $3250.

          * A typical loaf of bread is about half flour, half water (by mass), with about 400g of flour. Water is recycled. The launch cost for the flour for the loaf of bread is $2,50.

          * Launching a 200t habitat ring segment (a full launch) is $2M in launch c

          • by Rei ( 128717 )

            ED: The pricing figures were pre-inflation and pre-Starship expansion, so probably best to tack on another 50% for the "goal" - before tacking on whatever factor you expect for price growth beyond the goal, and profit atop that.

            • by Mal-2 ( 675116 )

              Usually you would just specify "2020 dollars" or some other fixed point that would automatically cancel out inflation so you don't have to worry about it.

        • Re: (Score:2, Insightful)

          by Viol8 ( 599362 )

          No sane person is going to want to live in a tin can in space and as for holidays - yeah , right. There's only so long you can stare out of a window before extreme boredom sets in. Maybe a night here or there but re-entry vehicles arn't cheap and can't be made in that quantity anyway.

          To to rejoin the real world mate, not some sci fi fantasy dreamworld you seem to be living in.

          • by Big Hairy Gorilla ( 9839972 ) on Wednesday June 19, 2024 @08:35AM (#64560675)
            I'd have to agree with Rei. No matter how dumb an idea is, once proposed, someone WILL do it.
            Getting your news from TikTok is... pretty ridiculous to think of some rando on TT as a trusted news source YET apparently X number of Americans are doing just that. (based on an article posted here in the last week or two.)

            So, 100%... a ton of rich dummies are going to want to vacation and live in orbit.
            I know people who have spent 50,000 to 100,000 on a vacation... so whats the diff?
            The novelty alone will attract lots of people with that kind of disposable money.
            Sanity isn't as popular as it once was.
            • I think there's a huge difference between a long stay and a couple of days.

              Going up, floating around in zero g and returning after 1-2 'nights' could be interesting but after that? To do what? Going on vacation means seeing new things all day every day, new people, food, sights, sounds, experiences. After, say, the first 12 hours in space in a big can, what more can a civilian experience?

              • You again!
                There's going to be the novelty for sure.. but you have a good point.. from what I've read you get headaches and swelling in the legs and stuff like that... doesn't sound very attractive to me.. and I suspect you're right that once you experience that.. you may find it not so great.
                I won't be going thats' for sure, would have been interested when I was younger, but theres no novelty in suffering for me anymore :-)
                • by Rei ( 128717 )

                  A toroid can be spun to create artificial gravity. Of course there's a balance to be struck, since there's two main things people want from space: seeing the Earth / space from above (check), and zero-G (not check). This can however be addressed by adding spokes to the design and a central hub, which also simplifies transport and docking, with the hub at low-to-zero G. Spokes also simplify movement and increase livable space, since you don't have to leave hallways / crawlways within the toroid.

                  Indeed, I t

              • by Mal-2 ( 675116 )

                Zero-G sex. Lots and lots of zero-G sex. It's like asking "what are you gonna do on Spring Break for a whole week, can't you get in all your partying in two or three days?"

            • by Viol8 ( 599362 )

              "I know people who have spent 50,000 to 100,000 on a vacation... so whats the diff?"

              Given each time someone comes back it uses up a launch module I'd put the price somewhere between $10^7 and $10^8 even if 2 people share the ride back.

              • I thought that Virgin, for comparison, was blabbing about prices in around 250,000 for a space tourist?
                Not sure when they were proposing, but the rocket cos are keen to get the price down and blow alot of pollutants into the atmosphere on a daily basis.
              • by bgarcia ( 33222 )

                Given each time someone comes back it uses up a launch module...

                Starship doesn't get "used up". It is completely reusable.

                That's exactly how SpaceX plans to bring spaceflight costs down by a couple orders of magnitude. They won't be throwing any part of the rocket away.

            • I woulding climb into a submarine that some idiot built and pilots himself. But there are enough rich people lacking in basic self preservation to make even insane projects profitable. And at the very least thereis some solid engineering behind SpaceX, even if the marketing concept is looney.

              • that's an interesting point.
                We work IN technology, and know the so many flaws, bugs, the drawbacks... a ton of people have blind acceptance of all new stuff... the submarine thing gives me the shivers! aaeeeeeeeee. But we have AI all over the tech news and there seems to be a lot of blind agreement over there too. I doubt it's going well, beyond the fund raising. The predators are leading the willing sheep hungry for something new. I basically only trust what I built, because that's what works, and I can de
        • "People who want to live in space (permanently" I don't know why anyone would live sealed inside what will amount to a submarine or a few linked shipping containers at best for the rest of their lives no matter how good the view is. The sci-fi romance would wear off pretty quickly, I think.
    • If I'm understanding the chemistry right, all this does is frontload the damaging effects of the various chlorine-based compounds while removing them from the ozone layer faster.

    • by dbialac ( 320955 )
      Take a step back and realize that this article seems to be centered around a bunch of researchers trying to get additional funding. Considering how vast the earth is and how small a satellite, and especially a microsatellite, typically is and how few there are and will likely ever be. 30,000 sounds like a big number, but take 30,000 things and put them all over the surface of the earth. How likely is it that you'll encounter one on any kind of a regular basis? I'm far from a climate denier. I have 15 solar
      • What you don't seem to acknowledge is that earth to sat technology is going to boom. They have already done a successful uplink test from a normal cellphone to a satellite. This is all just the tip of the iceberg.
        • by dbialac ( 320955 )
          Actually, I do acknowledge that. You're not understanding that even at scale, say at a million, there are going to be very few of these things compared to the size of the earth. That continues at 2 million. It's not like people are all going to have their own personal satellite. The number will scale up to a point, after which significant growth will stop. I'll also point out, which I didn't previously mention, that longevity of satellites is going to improve more and more because companies have a financial
      • Whatever damage these satellites can do in total, it's akin to pissing in the ocean while a massive chain of toxic waste producing plants dump into it unfiltered and nonstop. Like when a company claims to be "green" and has all of it's production done in countries with almost non existent environmental protection laws.
    • by RobinH ( 124750 )
      I agree. I'm glad someone is doing the research and running the numbers, and I want the companies and regulators involved to take a cold hard look at the data and make logical and rational decisions. It bothers me that headlines are already drawing conclusions about this. Get the data, do the math, and if we need to change something, do it. There doesn't need to be any drama.
    • Because we spend $3 billion a year running the international space station and while some of that is research projects a lot of it ain't and that's still seven people or 35,000 per person per month... I mean I can rent a two bedroom in Manhattan for 3K a month...

      The real problem with starlink is that not every one of those satellites comes down and we are in a real danger of trapping ourselves on this planet because we've just put too much junk in space and we can't launch anything anymore. But is a spec
      • of thy lord and savior Elon (Praise Be His Name!).

        I got some Karma to burn, so I'm just gonna have a nice laugh right now at all the Muskheads who are gonna lose their shirts in a few years when Tesla collapses. Don't believe me? What do you think happens to a car company that needs a $7500 gov't subsidy to make a profit when that subsidy goes away and their CEO has extracted $55b from the company right when it needs it most to update their 5 year old platform following a disastrous Truck launch?

        Her
        • by Rei ( 128717 )

          Please short Tesla. You'll definitely do better than all the TSLAQ people who have been writing the same thing for the past decade ;)

          On a side note, if you do take the tongue-in-cheek advice above: don't short via puts or short shares. By stock and then write covered calls well below the current SP. Why? It's also a short position (it's a bet that the stock is on route to being approximately the strike price of whatever calls you wrote around the expiry date of those calls), but the latter gets you a lo

    • If it's acting as a catalyst, it wouldn't be on the list because it doesn't have a direct effect on its own. What it's doing is speeding up reactions that were already happening. Whether this has an ongoing effect or just one-time as the levels of the other chemicals that react with it reach a new equilibrium is probably unknown.

    • It’s worth noting that SpaceX could completely remove aluminum from the satellites if this turns out to be a problem.

    • by Kisai ( 213879 )

      Unless building a "ring habitat" is in the cards, there might be push back against further satellite launches unless the launcher is willing to commit to changing the material's it's made of that affect the ozone layer.

  • Anything that prevents them from blotting out the stars and making the sky into a bunch of statically moving grids is a good thing.
    • If indeed the satellites do damage the ozone hole, perhaps it should be mandatory that those who earn money from putting up the satellites put cash in escrow to help take them down if found to be making life on earth in jeopardy? That financial protection should protect the sky view faster than anything else.
      • The damage is on a 30-year delay. That's how long it takes from the time the satellite deorbits until the particles reach the ozone layer. Also, taking the satellites down is kinda what the problem is.

      • by ls671 ( 1122017 )

        I think they last 5 years because that's when they run out of fuel. Somebody might eventually figure out a way to re-fuel them. It's is currently cheaper to just let them crash I think.

    • by Rei ( 128717 )

      There are 6078 Starlink satellites in orbit. How much does the night's sky look like a static moving grid to you?

      At an optimal position for reflecting light to you, Starlink satellites are about magnitude 6; the average Starlink satellite will appear 1-2 magnitudes higher than that at any given point in time.

      To even have a chance at seeing a mag 6 Starlink satellite (excluding those recently launched which are heading to their orbits, which are much brighter), assuming you have excellent vision, you first

      • by Rei ( 128717 )

        ED: sorry, not a trillion - magnitudes aren't log10, they're 2.512x. 12 orders of magnitude difference is 63130.

        But still, 12 orders of magnitude is a lot: there's only 6 orders of magnitude difference between ISS's peak magnitude and the full moon, and 14,2 between the full moon and the sun.

        • You are talking about the number that is up there now. This is just the beginning testing phase. Wait until there are fifty companies up there. I live in a fairly remote area and I'm far north, so for me to see any it is pretty unusual but they seem to be pretty regular now.
          • by Rei ( 128717 )

            What you're seeing is almost certainly not Starlink satellites, if they're bright enough to be noticeable. Starlink satellites are - except shortly after launch** - "strain your eyes in an optimal location to try to catch the faintest of glimpses of them". If that's not what you're describing, you're seeing something else. For example, BlueWalker 3 - an experimental cell phone communication satellite - has ~60 square meters of solar panels which can reflect light straight at Earth, and when doing so is br

      • > If you see something bright moving across the night's sky, it's almost certainly not Starlink

        It's aliens.

    • Anything that prevents them from blotting out the stars and making the sky into a bunch of statically moving grids is a good thing.

      Capitalist Greed, doesn’t even acknowledge Profit or Purpose in astronomy, and offers about as much respect or concern. Maybe a multi-trillionaire will find Guilt on their death bed so that they may donate a few dollars to the stars they covered for profit.

  • I seem to recall similar mentions of ozone damage done by going into space at all. And other versions of human existence angering the gods, technology being a sin, "Man was not meant to fly," and so on.

    The media screamed its 90-IQ heads off about satellite albedo interfering with astronomy, which led almost immediately to the entire issue being obviated. Then it started fantasizing about Kessler syndromes, so orbits were lowered to reduce the likely downtime of disabled sats. Now the problem is reentr
    • by drinkypoo ( 153816 ) <drink@hyperlogos.org> on Wednesday June 19, 2024 @08:38AM (#64560687) Homepage Journal

      Reentry pollution is a real problem if the numbers increase as they are projected to do. There are however some efforts to decrease it, for instance experimenting with using wooden cases [directindustry.com].

    • Astronomy IS interfered with. They just have to have a massive list of all the satellites and track their position to avoid recording bad data.

      • Just gonna ignore the work done on Starlink to avoid harming their data?
        • They're doing great on not reflecting as much sunlight, but that still doesn't change the fact that they literally have to transmit data in a frequency range that interferes with actual data being gathered. This is not something that can be fixed with the design. You have to specifically ignore sensor data for pixels during the time the satellite is passing over. There's plenty of sensor data ignoring that brief moment, but if you don't ignore it it will contaminate the results.

          Decoding and tracking satel

  • by Framboise ( 521772 ) on Wednesday June 19, 2024 @07:30AM (#64560499)

    The first point that is not discussed should be to compare the daily mass of satellites burning in the upper atmosphere with the daily 5-300 tons of meteorites and interplanetary dust that do the same.

    • Come-on, dont confuse the matter with facts.
      • Come-on, dont confuse the matter with facts.

        What fact? The point is being discussed and deubunked right in TFS. Rather than jumping on any comment regardless of how ignorant that you agree with, try reading the summary or... (yeah I know, Slashdot) the fucking article. You may learn something and look less like someone who is "me too!"'ing ignorance.

    • You didn't even need to read TFA. That's literally discussed in the fucking summary.
      • No, they have clearly no idea how much more meteoritic material is added to the atmosphere, of order of 100 times more what they estimate.

    • Good to hear from yet another contrarian f^ckwit who wouldn't even bother to read the summary, much less the actual article it links to.

    • Typical space rocks are mostly iron-nickel, not much aluminum.

    • by njvack ( 646524 )

      From TFA:

      Because it's effectively impossible to collect data from a spacecraft that's burning up, previous studies used analyses of micrometeoroids to estimate potential pollution. But micrometeoroids contain very little aluminum, the metal that makes up 15% to 40% of the mass of most satellites, so these estimates didn't apply well to new "swarm" satellites.

      To get a more accurate picture of pollution from satellite re-entry, the researchers modeled the chemical composition of and bonds within satellites' m

  • Humans act as though we are somehow not connected to the universe that we inhabit, and that our actions are without consequence. And if ever those consequences are brought to light - the collective response is to say "Nuh uh!"
  • Our current bans on the production of CFCs is aimed at reducing a class of molecules that are responsible for transporting chlorine into the upper atmosphere. Where UV radiation breaks it down, releasing chlorine atoms which in turn destroy ozone. Bans in place, everyone has been patting themselves on the back over the reduction of CFCs, upper atmosphere chlorine and ozone destruction.Job well done.

    Now, it appears that aluminum oxide from satellite re-entries can catalyze (Please, not "spark". We're all ad

  • Now analyze the consequences to Ozone from atmospheric nuclear detonations with mushroom clouds billowing up into this stratosphere.

    I think it is 5 kilotons of Nitric oxide per megaton of explosive yield.

    NO + O3 --> NO2 + O2
    NO2 + O --> NO + O2
    net O + O3 --> 2O2

    Enough tonnage was detonated to destroy every molecule of Ozone 4x over in this catalytic reaction.

    One way to mitigate the damage might be to crack down on Nitric oxide emissions from automobiles, to ban chlorofluorocarbons (and pin it on the

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