[HN Gopher] Potential ozone depletion from satellite demise duri...
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Potential ozone depletion from satellite demise during atmospheric
reentry
Author : nobody9999
Score : 135 points
Date : 2024-06-13 10:06 UTC (12 hours ago)
(HTM) web link (agupubs.onlinelibrary.wiley.com)
(TXT) w3m dump (agupubs.onlinelibrary.wiley.com)
| isodev wrote:
| Very interesting study. I guess putting things in orbit is
| absolutely going to cost us but I hope we will have this under
| control before it gets out of hand.
|
| Unfortunately, just like green house gases, it requires the very
| people who benefit from ignoring these kind of problems to pay
| attention and well...
| DennisP wrote:
| One of the main reasons we have governments is to solve those
| sorts of problems. That's how the ozone problem was
| successfully addressed before.
| hi-v-rocknroll wrote:
| The Montreal protocol worked because it was focused on a
| limit set of changes. Something similar could also work again
| if metal satellites and uncontrolled hypersonic reentry
| spaceship metal parts were outlawed as well.
|
| Unfortunately, the lack of a gradual set of limited changes
| is why the same process cannot be replicated for climate
| change remediation. Countries are trying to tackle the entire
| problem as an "impossible" monolith rather than breaking it
| up into separate industry and lifestyle practices to address
| incrementally.
| renhanxue wrote:
| The Montreal Protocol was nothing short of miraculous. It was
| the first international treaty to be ratified by all 198
| members of the UN (including the Holy See), and it's been
| called "perhaps the single most successful international
| agreement to date" by former UN Secretary General Kofi Annan.
| It's one of history's greatest achievements of environmental
| policy and international cooperation.
|
| The impact of CFC's on the ozone layer was first proposed in
| a scientific paper in 1973; the authors testified before the
| US House of Representatives in 1974 and significant funding
| was provided to study the problem. The Montreal Protocol was
| then signed in 1987 despite industry protests that the
| research was uncertain and there was no crisis that demanded
| urgent action. This was only 14 years (!) after the effect
| was first hypothesized. The discoverers of the effect won the
| Nobel Prize for chemistry in 1995.
|
| I don't expect to see anything even remotely as successful as
| the Montreal Protocol in my lifetime.
| boxed wrote:
| I would have liked an estimate of the natural sources to compare.
| martinclayton wrote:
| It's in section 3.3.
|
| - Natural Al estimated at 141.1 metric tons / year not varying.
|
| - Human-made: 2016: 5.36 tons, 2022: 41.7 tons, "future" could
| be 912 tons, i.e. more than 6x natural.
|
| I think the last figure is based on many planned large
| satellite constellations being deployed.
| golol wrote:
| If aluminum is the issue, could steel and plastics be a solution?
| Especially with Starship coming online, weight should be less of
| an issue.
| justin66 wrote:
| Anything's possible but the mass of the satellite won't cease
| to be something they need to optimize, even with a heavier
| booster. Those little satellites use thrusters themselves when
| they're in orbit.
| ginko wrote:
| There's also magnesium alloys, but if MgO is any better in
| the stratosphere is anyone's guess
| dylan604 wrote:
| There's a lot of really smart people that understand
| chemistry at a much better level than the typical reader on
| an internet forum. Do we really need to "guess"? Seems like
| we could study this to actually determine what would happen
| with controlled experiments. One might go so far as to call
| that the scientific method.
| s1artibartfast wrote:
| Nope, it is unknowable because ginko doesnt know /s
| kortilla wrote:
| The thrusters are to offset atmospheric drag, which
| accumulates with surface area, not mass.
| justin66 wrote:
| Weird half-true comment. Imaging satellites change their
| orbits, satellites operating in constellations station-
| keep, etc.
| roywiggins wrote:
| More mass still means you get less velocity out of your
| fuel, even if the drag stays constant.
| ordu wrote:
| But you also lose less velocity with the same drag.
| DennisP wrote:
| Since Starship itself is made of steel, it seems possible
| that the satellites could be as well.
|
| Assuming it's overall heavier, you have to carry more fuel,
| and then the rocket equation kicks in and you have to carry
| more fuel than that. That's all extra weight that makes your
| launch more expensive. But if your cost to launch is $30/lb
| instead of $1200/lb, you've got the budget for it.
| dr_orpheus wrote:
| But it's not just the cost of the launch, its also going to
| be the cost of the satellite itself.
|
| More mass means you need larger reaction wheels (or CMGs)
| to control the attitude of the spacecraft, larger reaction
| wheels means you need more power to control those reaction
| wheels, more power means you need more solar
| arrays/batteries, more solar arrays means more mass and
| moment of inertia...which means you need larger reaction
| wheels and on and on and on.
|
| Often people talk about the "tyranny of the rocket
| equation" but many other things on a satellite are the
| "tyranny of other non-linear systems"
|
| You can end up seeing that in companies like K2 Space.
| Their goal is to take advantage of cheaper launch costs
| with large, cheap satellites. But if you read in the
| article [0] they had to do things like develop new reaction
| wheels in house because "there was not a suitable supply
| chain for spacecraft bus like Mega Class". Starting from
| scratch on mechanisms like that for space is not super
| cheap.
|
| https://spacenews.com/k2-space-plans-first-launch-as-
| company...
| HPsquared wrote:
| Or visiting satellites to be deorbited and encapsulating them
| inside a re-entry vehicle with refractory tiles.
| adrian_b wrote:
| The Japanese have already been concerned by this problem for a
| few years.
|
| Their solution has been to develop satellites made mostly of
| wood, which will burn completely upon reentry.
|
| The first such wooden satellite is planned to be launched in
| September. It is intended mainly for collecting data about the
| behavior of wood in the outer space, e.g. on wood expansion,
| contraction and degradation, along with internal temperature and
| electronic equipment performance.
|
| An alternative to wood would be the use of synthetic polymers,
| but those are typically more sensitive to radiation, so more
| research would be needed for finding a suitable plastic and
| appropriate additives to decrease the radiation sensitivity.
|
| Wood or plastic would not be suitable for ships hosting humans,
| because they are not hermetic, but they may be an acceptable
| choice for satellites with a short lifetime and with much more
| relaxed constraints for the composition and pressure of the
| internal atmosphere (which may not be needed at all, e.g. when
| the internally produced heat reaches the external radiant cooling
| surfaces through solid paths or through pipes with circulant
| liquid).
| elil17 wrote:
| That would be so awesome! Reminds me of the sci-fi book
| "Children of Time"
| RALaBarge wrote:
| From the science we do on spider silk, who knows...we could
| one day see a Spider(Portiid)-derived hull cladding to fit
| around the lumber!
| will1am wrote:
| Yeah, the book has thought-provoking take on evolution
| IshKebab wrote:
| What about something like carbon fibre?
| dr_orpheus wrote:
| It is used quite a bit in the space industry already. But it
| is more expensive so it is usually confined to applications
| where you really need the weight savings, or you need
| something with a more controlled coefficient of thermal
| expansion. Thermal expansion of carbon fiber is small so you
| get less mismatch when you use it with things like optics or
| as part of solar panels.
|
| And a common place you find carbon fiber in the space
| industry is actually carbon fiber skinned aluminum honeycomb
| panels. Very light and very stiff.
|
| https://www.rockwestcomposites.com/shop/plates-panels-
| angles...
| mafuku wrote:
| So the Hearthians' timber ships made sense after all
| genpfault wrote:
| > Their solution has been to develop satellites made mostly of
| wood, which will burn completely upon reentry.
|
| "When finishing the surface of your wooden satellite you must,
| of course, use an orbital sander."[1]
|
| [1]: https://www.metafilter.com/203958/Yes-they-wood-build-a-
| sate...
| hunter2_ wrote:
| Could just send it into the astral plane.
| wil421 wrote:
| Just don't use a random orbital sander or you may lose your
| satellite.
| observationist wrote:
| Nanocrystalline cellulose (NCC) could be a great constituent
| component of a composite material. Not only would it burn, but
| anything that doesn't burn and makes it to the surface is
| biodegradable; there's lots of stuff that eats cellulose. NCC
| can be formed into highly strong and rigid structural pieces,
| or combined with carbon fiber, fiberglass, hemp, or other
| fibers to create ultra strong and durable composite material.
| high mechanical strength, with a tensile modulus of
| approximately 150 GPa and a modulus of elasticity ranging from
| 18 to 50 GPa. CNCs also exhibit excellent thermal stability,
| undergoing gradual thermal transitions and decomposition
| between 150 degC and 600 degC
| tivert wrote:
| > Their solution has been to develop satellites made mostly of
| wood, which will burn completely upon reentry.
|
| I like how the Google image search for "japan wooden satellite"
| (https://www.google.com/search?q=japan+wooden+satellite&udm=2)
| is gummed up with garbage AI generated images of satellites
| with wooden solar panels. This wooden Borg cube with off-kilter
| panels is my favorite:
| https://indianspacetechnology.com/wooden-satellite-
| lignosat-.... This one is also great:
| https://www.universetoday.com/161473/building-a-satellite-
| ou.... I guess the satellite went back in time to the
| Cretaceous period, where North America had an inland sea?
|
| The future is looking bright, guys!
| quasse wrote:
| Kagi returns basically the same result set including the AI
| generated slop, which is disappointing.
| tivert wrote:
| I'm not sure how they could do any better. AI is enabling
| the degradation of the public web, and that's what they
| search.
|
| Pretty soon the web's going to be one big Mikkelsen Twins
| ebook.
| lstamour wrote:
| Well, here's an actual photo they could have used: https:
| //www.japantimes.co.jp/news/2024/05/29/japan/science-h...
|
| And here is an earlier rendering from 2021: https://www.j
| apantimes.co.jp/news/2021/12/31/national/japan-...
|
| And it only took a simple Google search to find, from a
| reputable news source.
| shadowgovt wrote:
| Without AI you'd still be looking at dozens of artists'
| mockups of wooden satellites because they have to put
| _something_ at the top of the blog post or news article to
| catch viewer attention.
| will1am wrote:
| But sill wood usage does have an impact on the environment too
| blackguardx wrote:
| So does corn. In fact much of the wood used in construction
| in the US is grown like corn in a cornfield.
| whatevaa wrote:
| Everything you do does. Question is how much.
| s1artibartfast wrote:
| I assume you mean the high atmospheric particulate. It would
| be interesting to see how this compares
| pdabbadabba wrote:
| It's an interesting effort, but the supposed issue addressed in
| the paper is not that aluminum does not fully burn up during
| reentry. It generally does, just like wood. It's that, when it
| does so, it releases alumina.
|
| Maybe this is better because the vaporized wood would. not
| release any alumina. But you'd then have to look at the impact
| of _wood 's_ combustion products when introduced directly to
| the upper atmosphere. I'm not sure anyone has seriously studied
| that question.
| jl6 wrote:
| I couldn't see a quantitative estimate of how much ozone would be
| depleted in a typical year as a result of the extra catalyst
| being present. If it's only ~hundreds of tons, that seems both
| immaterial (there are about 3 billion tons of ozone in the
| atmosphere currently) and potentially easy to replace (fly up
| there and dump some fresh ozone).
| gmm1990 wrote:
| I think it says its a catalyst, for some chlorine reaction. So
| its not out of the question 300 tons (per year) could effect
| ozone concentrations.
| marcosdumay wrote:
| There's absolutely no estimation of the impact. Your 300 tons
| of activated chlorine per year idea is as baseless as the
| GP's 300 tons of ozone, but the GP is aware that his number
| is a complete invention.
|
| Any exercise in making numbers out of nothing is completely
| useless.
|
| (Besides, is chlorine activation really a bottleneck in ozone
| depletion? AFAIK it gets activated by UV light quite
| quickly.)
| gmm1990 wrote:
| GP never implied the amount of ozone just the amount of
| aluminum oxide. All I know is catalysts can speed up
| reactions by orders of magnitude. CFCs actually created a
| hole in the ozone layer so its not like human activities
| haven't accidentally created problems before. Probably
| something that at least needs to be ruled out.
| oasisbob wrote:
| Correct. That's the same way I read that comment.
|
| More fundamentally, chemical catalysts by definition are
| not consumed by the reactions they catalyze.
|
| Think: a cheese grater. It doesn't react with the cheese,
| so a few ounces of grater could make hundreds of pounds
| of grilled cheese.
|
| A hypothetical 300 tons of catalyst is not limited
| stoichiometrically to how much substrate it would affect.
| ldoughty wrote:
| If starlink thinks it may have 40,000 satellites at full
| capacity[1] .. and we expect at least 1 if not 2 competitors..
|
| With a 5-year lifespan for an LEO sat, that's potentially
| 120,000 deorbits every 5 years...
|
| That will add up quickly... I don't know the science of
| aluminum oxide increase to ozone depletion.. but this can
| certainly warrants more research and consideration
|
| 1: https://starwalk.space/en/news/spacex-starlink-satellites-
| ni...
| aftbit wrote:
| https://www.antipope.org/charlie/blog-static/2024/05/on-
| mist...
| AtlasBarfed wrote:
| Can't they spray some ozone as they deorbit?
| s1artibartfast wrote:
| No, but I imagine they could include some other solid mass
| that has a counter effect.
| mathsmath wrote:
| The satellites are typically much smaller than historic
| satellites. I think ~50-60 are launched in a fairing that
| would house 1 or two older-style satellite.
|
| Does the mass make a difference?
| kemotep wrote:
| All of those starlinks are designed to burn up though. And
| there will be many thousands more of them then there ever
| was of those older larger satellites.
| happyopossum wrote:
| Why would the number of satellites be pertinent here? It's a
| mass problem, and starlink satellites are tiny compared to
| most of the satellites that are up there.
| whoknowsidont wrote:
| Many little number make big number. Mhmmm.
| s1artibartfast wrote:
| Im guessing it would make sense to release more pro ozone
| catalyst. It may even be an option to release more it from
| the ground, as an inverse to CFCs.
|
| NOx is also has a global cooling effect, taking the edge off
| climate change.
|
| NOx and VOCs from power plants and diesel vehicles produce
| ozone.
| BurningFrog wrote:
| Catalysts don't get consumed by the reactions they facilitate,
| so the weight of the catalyst compared to the ozone doesn't say
| much about the effect.
|
| For example, consider that a car exhaust catalyst contains ~5
| grams of platinum, and AFAIK, that doesn't really "wear out".
| pwndByDeath wrote:
| I'm no chemist but I noticed this other researcher wanted to dump
| literal tons of another oxide into the atmosphere to counteract
| global warming.
|
| https://iopscience.iop.org/article/10.1088/1748-9326/aae98d/...
| elil17 wrote:
| An oxide is just a molecule with one oxygen atom and one other
| element. Different oxides would have different effects on
| atmospheric chemistry.
| astrodust wrote:
| "Nitrous oxide best oxide." -- Dominic Toretto
| dmbche wrote:
| See "Snowpiercer"
| selimthegrim wrote:
| see https://news.ycombinator.com/item?id=37344251
| datameta wrote:
| To geoengineer or not to geoengineer, that is the question. Can
| we build models that six nines assure us of a small stable
| improvement that stays near linear behavior, or asymptotic
| better yet?
| londons_explore wrote:
| One option is to make the satellite survive re-entry rather than
| burn up. Then just re-enter over a desert like australia or the
| sahara so you can go find and collect the junk.
|
| Single-use heat shields for smallish things like satellites are
| quite easy I believe, although fold-out items like solar panels
| would need to be designed to fold-in again.
| ferfumarma wrote:
| Please fine the companies who did this. This is a global problem
| that affects everyone, but especially those of us in Australia.
| pdabbadabba wrote:
| Just so you know, the comment immediately below yours proposes
| a solution where satellites are designed not to burn up at all
| and are aimed at Australia during reentry.
|
| > One option is to make the satellite survive re-entry rather
| than burn up. Then just re-enter over a desert like australia
| or the sahara so you can go find and collect the junk.
|
| So be careful what you wish for!
| idiotsecant wrote:
| Parent post: won't someone please think of Australia!!!!
|
| Global military industrial complex: Now that you mention
| it...
| Culonavirus wrote:
| Manufactured outrage.
| hi-v-rocknroll wrote:
| Maybe or maybe not. I want to know what "significant" means in
| terms of stratosphere effects in DU/km^2 per kg of aluminum
| oxide.
| ck2 wrote:
| Privatize the profit (and government helps pay for development)
| then socialize the cleanup costs.
|
| Why doesn't every messy industry like this have to pre-pay
| massive insurance fees ahead of time for known and unknown
| damages?
|
| Note X isn't the only one with thousands of satellites, there are
| several startups that are launching their own thousands. Soon
| we'll have debris and burnup of dozens a day, that will add up.
| mathsmath wrote:
| It's kind of like the industrial revolution. I don't think
| anyone knows what will happen (it's the classic human behavior
| of kicking the problem down the road), but the collective human
| mind has decided we want global connectivity now that it's
| cheap.
|
| I can't see the cat going back into the bag (or reengineered)
| unless there have been proven negative results like the ozone
| hole directly linked to CFCs.
| selimthegrim wrote:
| Other work on this from January but focusing on temperature in
| stratosphere: https://arc.aiaa.org/doi/abs/10.2514/6.2024-2169
| sandworm101 wrote:
| How about just not letting them burn up? Give the core an organic
| heatshield (wood?) and let it crash into the ocean. Even
| thousands of them each year would be nothing compared to the
| amount of waste regularly dumped into the oceans, an acceptable
| compromise over ozone depletion.
| BurningFrog wrote:
| If thousands of intact satellites crash to Earth yearly, they
| will hit and kill people, even just over the oceans.
|
| People will also be upset about the environmental damage, real
| or imagined.
| sandworm101 wrote:
| Thousands of small rocks fall from space every year, have
| done so for a very long time. Human deaths are almost unheard
| of.
| mathsmath wrote:
| Not only this, but they fall in a randomly-distributed
| fashion. Most satellites are still under control and
| steered to a predetermined area for reentry over the South
| Pacific.
| dr_orpheus wrote:
| > Most satellites are still under control and steered to
| a predetermined area for reentry over the South Pacific.
|
| This is not true, most satellites do not perform
| controlled re-entry. In order to perform controlled re-
| entry, you need to have enough thrust to perform the
| final de-orbit maneuver in a short amount of time before
| you get so low that you start to lose attitude control of
| the spacecraft and wouldn't be able to guarantee you are
| firing your thrusters in the correct direction. To do
| this in a short amount of time means you need a high
| thrust system, in other words a chemical propulsion
| system and not electric propulsion.
|
| All of the Starlink satellites use electric propulsion to
| do their de-orbit so they are performing uncontrolled re-
| entry. NASA's Orbital Debris Mitigation Standard
| Practices (ODMSP) say that you can perform uncontrolled
| re-entry if the probably of casualties on the ground is
| less than 1 in 10,000. There are NASA analysis tools that
| are used to do that assessment of what kind of debris
| would survive re-entry. This is likely getting updated in
| the near future to be more conservative though as there
| was recently a piece of an old ISS battery they thought
| would burn up hit someone's house in Florida:
|
| https://spacenews.com/uncontrolled-reentry-of-space-
| debris-p...
| mathsmath wrote:
| I had to check, but you're not wrong - only 47% of total
| are controlled re-entries. (https://en.wikipedia.org/wiki
| /Spacecraft_cemetery#cite_note-...)
|
| I thought I recently read about a law requiring a de-
| orbit plan for anything launched. I would assume if most
| of the mass doesn't burn up (Starlinks mostly burn up),
| it would require them to hit the South Pacific patch or
| similar.
| will1am wrote:
| I think as we continue to expand our use of space, it is crucial
| to consider the environmental impacts!
| LeifCarrotson wrote:
| > _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..._
|
| On the scale of the planet, that's incredibly tiny. 17 metric
| tons of aluminum oxide can be made by oxidizing a cube of
| aluminum about 1 meter on a side. The catalytic action must be
| incredibly potent!
|
| Wolfram helpfully tells me that the mass of the mesosphere is on
| the order of 10^12 tons, so that's on the order of parts per
| trillion.
| shadowgovt wrote:
| It's tiny, but it may be enough if the wind currents are
| concentrating it, as happened with CFCs doing away with the
| ozone layer over the South Pole.
| yourMadness wrote:
| Is there even an estimate of the impact on ozone in the paper?
|
| You don't need a science paper to end up with "letting satellites
| burn up in the atmosphere results in burned satellite dust in
| atmosphere", do you?
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