Technology

59589 readers

2972 users here now

This is a most excellent place for technology news and articles.

Our Rules

Follow the lemmy.world rules.
Only tech related content.
Be excellent to each another!
Mod approved content bots can post up to 10 articles per day.
Threads asking for personal tech support may be deleted.
Politics threads may be removed.
No memes allowed as posts, OK to post as comments.
Only approved bots from the list below, to ask if your bot can be added please contact us.
Check for duplicates before posting, duplicates may be removed

Approved Bots

founded 1 year ago

MODERATORS

704

SpaceX's Starlink May Be Keeping the Ozone From Healing, Research Finds (futurism.com)

submitted 5 months ago* (last edited 5 months ago) by Gsus4@programming.dev to c/technology@lemmy.world

187 comments fedilink hide all child comments

Abstract from the paper in the article:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109280

Large constellations of small satellites will significantly increase the number of objects orbiting the Earth. Satellites burn up at the end of service life during reentry, generating aluminum oxides as the main byproduct. These are known catalysts for chlorine activation that depletes ozone in the stratosphere. We present the first atomic-scale molecular dynamics simulation study to resolve the oxidation process of the satellite's aluminum structure during mesospheric reentry, and investigate the ozone depletion potential from aluminum oxides. We find that the demise of a typical 250-kg satellite can generate around 30 kg of aluminum oxide nanoparticles, which may endure for decades in the atmosphere. Aluminum oxide compounds generated by the entire population of satellites reentering the atmosphere in 2022 are estimated at around 17 metric tons. Reentry scenarios involving mega-constellations point to over 360 metric tons of aluminum oxide compounds per year, which can lead to significant ozone depletion.

PS: wooden satellites can help mitigate this https://www.nature.com/articles/d41586-024-01456-z

you are viewing a single comment's thread
view the rest of the comments

[–] JohnDClay@sh.itjust.works 113 points 5 months ago* (last edited 5 months ago) (9 children)

SpaceX has been receptive to design changes to starlink in the past to minimize impact, like decreasing reflectivity and reflection angles for astronomers. They might be receptive to moving to different alloy for the body construction.

Magnesium comes to mind that would be light but expensive. Steel alloys might be cheap and heavy options for later when starship is operational. Would those have similar effects on ozone, or is it only the aluminum oxides?

[–] Gsus4@programming.dev 55 points 5 months ago* (last edited 5 months ago) (1 children)

Magnesium oxides can also serve as a catalyst for lots of reactions, but I'm not sure if it will have the same effect in this specific context, I'd guess it would.

That's why I added the link to the wooden satallites, that also reduces the metal debris somewhat and reduces other effects like radio interference.

[–] JohnDClay@sh.itjust.works 21 points 5 months ago (1 children)

Wood is interesting, but the article doesn't address off gassing at all, which is a huge problem for communication satellites. Is there a way to keep the wood from off gassing? For 3d prints in vacuum, they metal coat them to keep the gas inside. Or maybe you could resin soak them? With hopefully an extremely UV stable resin. But I didn't know what the weight trade looks like then, resin is heavy.

But if you're looking composites anyway, carbon fiber would be another great option. Lightweight but with a few manufacturing constraints. But should burn up to carbon dioxide on reentry.

[–] TopRamenBinLaden@sh.itjust.works 2 points 5 months ago* (last edited 5 months ago)

I just read an interesting research article from NASA that shows that carbon fiber survives reentry better than our previous scientific consensus claimed.

Some carbon fiber will burn up into carbon dioxide, but a good chunk of it will surprisingly survive reentry conditions. I think you are very right that it should be a better material to use for starlink.

load more comments (7 replies)