One to two Starlink satellites are falling back to Earth each day • Hacker News Board

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

#81

Post by JumpCrisscross » Mon, Oct 06, 2025, 7:12 PM UTC

ggoo wrote: post #20

loeg wrote: post #8

Earlier quoted context omitted.

Personally, I've never suffered from satellite plasma or light pollution from satellites , or spectrum allocation. I suspect most of the 100% are like me.

Scientific advancement has suffered from the light pollution and that advancement is a driving force behind your modern life. So you have (or will) suffer indirectly over time.

> Scientific advancement has suffered from the light pollution

Has it?

Destroying the Amazon destroys information. Light pollution simply raises the cost of our accessing it. I suppose one could model this out to some effect on deep-space astronomy's productivity. But if that effect is real--and I've seen zero evidence it is--the solution is a tax on satellite launches to fund more observatories.

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

#82

Post by JumpCrisscross » Mon, Oct 06, 2025, 7:12 PM UTC

dweinus wrote: post #67

chermi wrote: post #21

Earlier quoted context omitted.

I'd wager many of those connections are serving much more than one person, considering they're often hubs in rural areas. But screw them. It's interesting how if it's anti-elon, it's ok to complain about how the poor are causing the privileged some difficulties.

If we wanted to subsidize internet for rural and low-income communities responsibly, we could invest in fiber and other solutions, and control the externalities (this is exactly the ReConnect program is). Starlink is not that, it is a classic case of privatizing profits by socializing hidden externalities, in this case to the entire world. Externalities in the form of pollution that will cost us all more than fiber i…

> If we wanted to subsidize internet for rural and low-income communities responsibly, we could invest in fiber and other solutions, and control the externalities

Running cables across out land is less impactful than lofting satellites?

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

#83

Post by JumpCrisscross » Mon, Oct 06, 2025, 7:13 PM UTC

xnx wrote: post #16

oceanplexian wrote: post #10

Earlier quoted context omitted.

A single terminal could serve an entire African village. It's also serving use cases in the Ukraine war, ships at sea, Antarctic research stations, numerous aerospace and military use cases, and so on. DTC is provide texting and emergency services to countless people who might need it in an emergancy, like we saw in North Carolina. Last and most importantly, Starlink exists is to create revenue for SpaceX and to fund…

> The value to humanity of Starship succeeding at its goals is extremely high. Starship to orbit sounds useful, but Starship to Mars is near useless. If that's what rich people want to spend their money on, go nuts.

> Starship to Mars is near useless

Apollo to the Moon was near useless by that metric. We wouldn't have Starship to orbit if we hadn't gone to the moon.

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

#84

Post by JumpCrisscross » Mon, Oct 06, 2025, 7:16 PM UTC

Ancapistani wrote: post #80

xnx wrote: post #16

Earlier quoted context omitted.

> The value to humanity of Starship succeeding at its goals is extremely high. Starship to orbit sounds useful, but Starship to Mars is near useless. If that's what rich people want to spend their money on, go nuts.

> Starship to orbit sounds useful, but Starship to Mars is near useless. I strongly disagree. If "Starship to Mars" is a possibility, then so is "Starship to the asteroid belt". It's very close to "Starship to the asteroid belt, capture asteroid, return to Earth orbit" - and that's very close to orbital mining of metals that are rare and valuable on Earth.

> It's very close to "Starship to the asteroid belt, capture asteroid, return to Earth orbit"

To put this into perspective, an Earth-Mars round trip costs about 15 km/s; Earth-main Belt about 13 km/s.

You'd need to add Δv for returning the mass of the asteroid. But you get your reaction mass for "free."

(To be clear, we are hundreds of billions of dollars of capex and decades away from asteroid mining. But the work to get there is decently in line with the work we would need to establish a logistical chain to Mars and back.)

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

#85

Post by schiffern » Mon, Oct 06, 2025, 7:16 PM UTC

JumpCrisscross wrote: post #75

schiffern wrote: post #64

Earlier quoted context omitted.

>0.01% of anthropogenic ozone depletion The sheer percentage increase in stratospheric AlO is still alarming.[0] Satellite reentries in 2022 (ie mostly pre-megaconstellation) were already raising stratospheric AlO levels by 29.5% above normal levels (with satellites adding 'only' 17 t/year), but megaconstellations could raise that to ~480% above natural levels (360 t/year). This isn't a rounding error, it's a non-tri…

> Satellite reentries in 2022 (mostly pre-megaconstellation) were already raising stratospheric AlO levels by 29.5% above normal levels Those findings are simulated, not observed. Hence "potential." > it's a non-trivial change in chemical composition over the entire globe, and effecting a complex and poorly-understood part of the climate system. What could go wrong? Perhaps a lot. Perhaps not much. It's a good questi…

Interesting. Incidentally SpaceX is probably the most likely to preemptively adopt those measures.

Of all the megaconstellations, SpaceX has historically been the best at being a "good neighbor," with low orbits for debris and lots of engineering to reduce brightness.[0] But hype around SpaceX gives the real bad actors a pass, for example AST is much worse on brightness,[1] and OneWeb and Qianfan are much worse on debris risk.[2]

[0] https://www.youtube.com/watch?v=MNc5yCYth5E&t=1717s

[1] https://spacenews.com/astronomers-raise-interference-concern...

[2] https://spacenews.com/chinas-megaconstellation-launches-coul...

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

#86

Post by nicce » Mon, Oct 06, 2025, 7:20 PM UTC

JumpCrisscross wrote: post #76

nicce wrote: post #59

Earlier quoted context omitted.

> For example, Starlink satellites orbit so low, that even if every single one of them collides and becomes dust, it will all decay and burn up in a matter of months, a couple years at most. That is way too long. The threshold we are speaking of cannot allow any fragments, because they start chain reaction and destroy more satellites. And there is always one which is on the highest level. What if that gets destroyed?

> threshold we are speaking of cannot allow any fragments, because they start chain reaction and destroy more satellites Kessler cascades are localised to specific orbits. In low-earth orbit, they're a problem for a few years. They're going to be annoying. But not catastrophic. > there is always one which is on the highest level Highest level?

> Kessler cascades are localised to specific orbits. In low-earth orbit, they're a problem for a few years.

> They're going to be annoying. But not catastrophic.

I think there is a misunderstanding about the whole term. If it is not a big problem, then it does not meet the definition. So there must be some threshold where they aren't problem. What is that threshold? Because certainly there isn't space for infinite amount of objects. Primary question is that whether that threshold matters on practice. If it is 70k, then it is certainly a problem, but who knows the exact number yet.

> Highest level?

There is always the one which is classified orbiting on the highest level in LEO. Also that object can get destroyed; which means it will start deorbiting and with a chance to hit some other object below.

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

#87

Post by JumpCrisscross » Mon, Oct 06, 2025, 7:23 PM UTC

everforward wrote: post #63

adastra22 wrote: post #33

Earlier quoted context omitted.

Rough napkin math would be negligible impact. The amount of lead in a satellite is very small, if not actually zero. The amount of lead added by burning coal is about 30 tonnes per day.

There is almost definitely a small, negligible amount of lead in the solder in them. Eg NASA requires a small (single digit I think) percentage of lead to prevent tin whiskering.

> almost definitely a small, negligible amount of lead in the solder in them

Emphasis on negligible. Assuming 0.07 to 0.28 ppm lead [1] in meteoroids, space is dosing us with half to 2 kg a year [2].

[1] https://www.sciencedirect.com/science/article/abs/pii/001670...

[2] https://earthsky.org/space/tons-of-extraterrestrial-dust-fal...

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

#88

Post by zevon » Mon, Oct 06, 2025, 7:23 PM UTC

nicce wrote: post #62

bryanlarsen wrote: post #61

Earlier quoted context omitted.

No it's not. Kessler simulations show those chain reactions happening over multiple decades.

It purely depends of the density of objects. The whole definition of the Kessler syndrome is about the estimation when the density is too much to handle.

Maybe this is helpful: https://aerospaceamerica.aiaa.org/features/understanding-the...

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

#89

Post by nicce » Mon, Oct 06, 2025, 7:23 PM UTC

JumpCrisscross wrote: post #78

nicce wrote: post #57

Earlier quoted context omitted.

> Starlink's orbits are so low that everything deorbits automatically. It is enough if it goes one round around. They can make a cascading effect which can destroy tens of satellites at once, and few fragments are enough. And closer to earth you are, less space there is. They can't all orbit on exactly the same level. There is always one which is on slightly higher level.

> closer to earth you are, less space there is Humans are bad at intuiting exponents. There is roughly 200x more volume in LEO than there is between the ground and cruising altitude. Plane changes, moreover, take a lot of energy--you aren't going to get enough energy out of a collision to pollute nearby orbits.

> going to get enough energy out of a collision to pollute nearby orbits.

There is no infinite space. The problem is exactly defining the number objects when that "small" amount of energy is actually enough to cause problems.

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

#90

Post by perihelions » Mon, Oct 06, 2025, 7:25 PM UTC

schiffern wrote: post #64

perihelions wrote: post #28

Earlier quoted context omitted.

It's postulated that the high aluminum content of satellites (for perspective, Bennu samples are only 1% Al), as oxidized Al2O3 particles in the stratosphere, catalyze chemistry that destroys ozone. But that's far from a quantitatively meaningful problem, at the current scale. This source[0] says satellite reentries are about about 12% of the space industry's contribution to ozone depletion (the big one is chlorine f…

>0.01% of anthropogenic ozone depletion The sheer percentage increase in stratospheric AlO is still alarming.[0] Satellite reentries in 2022 (ie mostly pre-megaconstellation) were already raising stratospheric AlO levels by 29.5% above normal levels (with satellites adding 'only' 17 t/year), but megaconstellations could raise that to ~480% above natural levels (360 t/year). This isn't a rounding error, it's a non-tri…

That's still much less than the aluminum from solid rockets, which have been ongoing since the 1970's. Per your own link,

> "In situ measurements showed evidence of a 1,000% increase in stratospheric aluminum levels from 1976 to 1984 (Zolensky et al., 1989), which was associated with the emission of hundreds of tons of such particles from solid rocket motors (SRM) during atmospheric ascent (Brady et al., 1994)"

If you follow Brady et al. (1994)[0], you'll read that every Space Shuttle launch (Table 1) deposited 112 tons of Al2O3 into the stratosphere (>15 km).

[0] https://apps.dtic.mil/sti/pdfs/ADA289852.pdf

This isn't a new phenomenon at all; in fact the peak alumina pollution from in the past (112 tons per STS launch) exceeds the worst-case future estimates from academic research (360 tons per year from satellite reentries).

(/meta Coincidentally, I once linked that exact Brady paper on HN, three years ago[1]. Actually, long before the current social media fad for being concerned about satellites. At the time I wrote, and this has truly aged well, "No one ever gave a shit").

[1] https://news.ycombinator.com/item?id=34812863