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One to two Starlink satellites are falling back to Earth each day

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Re: One to two Starlink satellites are falling back to Earth each day

#231

Post by ecommerceguy »

"What’s not usual is the atmospheric fallout. The fiery re-entry of even one Gen1 Starlink satellite produces about 30 kilograms of aluminum oxide vapor, a compound that erodes the ozone layer. A new study finds these oxides have increased 8-fold between 2016 and 2022, and the Great Re-entry Event increases this pollution even more.

To put this into perspective: Before the first Starlink launches began in 2019, only about 40 to 50 satellites re-entered per year. SpaceX just brought down ten years' worth in only six months, adding an estimated 15,000 kilograms of aluminum oxide to the upper atmosphere."

https://spaceweather.com/archive.php?view=1&day=05&month=08&...

Shout out to NEKAAL for watching the skys and keeping our little speck of dust a bit safer from the vast reality of space.

Re: One to two Starlink satellites are falling back to Earth each day

#232

Post by Dylan16807 »

lxgr wrote: post #169
Dylan16807 wrote: post #156

Earlier quoted context omitted.

Whatever you do to launch an object higher, it will return to its original altitude once per orbit. If you want to stay high you first have to boost up and then you have to boost again half an hour later, which will happen just about never with debris.

You'd still have an eccentric orbit intersecting some "higher" ones periodically, no? Certainly less dangerous than something "going the wrong way" in a given orbital shell, but not sure if it's completely negligible either.

For the lucky few pieces that launch at just the right angle, they'll spend a few months or years intermittently intersecting higher orbits.

But almost all the debris will either stay close to the original orbit or burn up within hours.

Re: One to two Starlink satellites are falling back to Earth each day

#233

Post by michaelmior »

zwily wrote: post #100
michaelmior wrote: post #51

Earlier quoted context omitted.

Not with a geostationary orbit. That must have a fixed radius. The problem is that satellites have to move to counteract the force of gravity to avoid falling out of orbit. But if they move too much or too little, then the satellite moves with respect to the earth and the orbit is no longer geostationary. (Caveat: Not an expert by any means, just someone who had a similar question and did some reading, so my answer m…

Starlink satellites aren't geostationary.

The parent comment wasn't specifically addressing Starlink.

Re: One to two Starlink satellites are falling back to Earth each day

#234

Post by matthewdgreen »

JumpCrisscross wrote: post #2

> Soon, McDowell told us, there will be up to 5 satellite reentries per day Starlink’s next-generation V3s, which will require Starship to launch, weigh in around 2 metric tonnes [1]. (They’re currently “around 260 and 310 kilograms” [2].) “Every day, Earth is bombarded with more than 100 tons [91 metric tons] of dust and sand-sized particles” [3]. So we’re talking about a 2 to 10% increase in burn-up by mass. (Not a…

See the first comment in this thread about aluminum oxide and the ozone layer. It’s not so much the amount, but what it is.

Re: One to two Starlink satellites are falling back to Earth each day

#235

Post by fragmede »

Fischgericht wrote: post #226
Fischgericht wrote: post #215

Earlier quoted context omitted.

You are very wrong here: Right now Starlink claims to be operating a mesh, but they are not. If they would want to build a mesh, Inter-sat links for NOT be used used to pipe through bandwidth to the "best" base station. It would be used for shared state to be able to prepare a handover. Synching state obviously is much easier and more stable if the neighboring sats can talk directly, instead of sharing it over their…

Can not reply to your anymore, guess we are nested too deep now? I think we are simply talking about two different things here. I mentioned 802.11r not due to the key exchange implementation details, but to point to the general point: Seamless handover requires shared state between cells. This is not about static vs dynamic routing, you are thinking on the wrong layer here. We are in L1+L2 land. On Starlink, the last…

What's different this time is the cost and time to orbit. SpaceX has been able to launch every three days in 2025. Viasat, Iridium, and everyone else who came before didn't have that. I don't have your spreadsheet to plug that bit of data into, and it's balanced by the number of satellites starlink needs, but governments tend to have a lot of money to keep the things they rely on running.

Re: One to two Starlink satellites are falling back to Earth each day

#236

Post by aaomidi »

allenrb wrote: post #201

Man, I dream of living in a world in which our biggest (or even a top-10) environmental concern is “debris from LEO burning up in the atmosphere”. Yes, most of us are pretty angry at/disappointed in Elon these days but there are better places to focus than this.

Some chemicals can be extremely potent climate problems. Starlink does represent an astronomical increase in these metals etc in the atmosphere.

Re: One to two Starlink satellites are falling back to Earth each day

#237

Post by dweinus »

JumpCrisscross wrote: post #206
dweinus wrote: post #199

Earlier quoted context omitted.

Per the article, Starlink runs 8k satellites with an average life of 5 years. They launch in payloads of 20-40 satellites. That's 50+ launches per year if everything goes perfectly. About a million pounds of kerosene per launch. Plus everything else that goes into the rockets and satellites. Then the pollution impact from the launches and reentries. Then the eventual need to clean up LOE to avoid Kessler Syndrome. So…

> About a million pounds of kerosene per launch Quarter of a million pounds kerosene per Falcon 9. Zero for Starship, which burns methane. (And thus emits pure methane, CO2 and water vapor.) > the eventual need to clean up LOE to avoid Kessler Syndrome Not a thing. (Search this comment thread for the term. There are good answers on the current state of research.)

https://www.upi.com/Science_News/2024/09/12/spacex-launches-...

...but sure, for the sake of argument, maybe it's only a quarter million lbs of kerosene 50 times a year, upper atmospheric pollution, and LEO crowding that gets solved by HN comments. ...instead of a dumb cable that doesn't come with a side of funding a billionaire neo-nazi. My bad.

Re: One to two Starlink satellites are falling back to Earth each day

#238

Post by terminalshort »

ecommerceguy wrote: post #231

"What’s not usual is the atmospheric fallout. The fiery re-entry of even one Gen1 Starlink satellite produces about 30 kilograms of aluminum oxide vapor, a compound that erodes the ozone layer. A new study finds these oxides have increased 8-fold between 2016 and 2022, and the Great Re-entry Event increases this pollution even more. To put this into perspective: Before the first Starlink launches began in 2019, only…

The fact that they quantified everything here except for the amount of ozone this actually destroys tells me that it's completely insignificant.

Re: One to two Starlink satellites are falling back to Earth each day

#239

Post by TheAlchemist »

lxgr wrote: post #183
TheAlchemist wrote: post #127

Earlier quoted context omitted.

Sorry, I was referring to the general stock market (mostly AI) bubble. As for SpaceX, it's pretty much impossible to know their finances - they don't publish audited accounts. We can just trust what Elon is willing to share with us.

What does a stock market bubble have to do with the profitability (i.e. not the valuation) of any given company? Are you arguing that the demand in Internet connectivity in rural/remote areas is somehow caused by an investment bubble as opposed to a long-term stable need?

No, I don't think there is any relationship there.

I'm saying that I highly doubt the real profitability of SpaceX / Starlink, and we will only see if it's really as good as they say, once the bubble pops and there is no inifinite capital, and maybe some accountability.

Re: One to two Starlink satellites are falling back to Earth each day

#240

Post by mensetmanusman »

ecommerceguy wrote: post #231

"What’s not usual is the atmospheric fallout. The fiery re-entry of even one Gen1 Starlink satellite produces about 30 kilograms of aluminum oxide vapor, a compound that erodes the ozone layer. A new study finds these oxides have increased 8-fold between 2016 and 2022, and the Great Re-entry Event increases this pollution even more. To put this into perspective: Before the first Starlink launches began in 2019, only…

Earth receives ~50,000 kg/day of cosmic dust (our mid-range assumption), 30 kg is 0.06% of that daily amount.
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