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We need to talk about Starlink

The Great Zaganza

Maledictorian
The Great Zaganza
Joined
Aug 14, 2016
Messages
27,198
So Musk send the first 60 Starlink satellites into orbit -
the first 60 of a planned total of 12,000 by the mid 2020s.

The goal is a global, everywhere accessible and faster internet.

this is a nice background on the technological and economic aspects of it:

https://www.youtube.com/watch?v=giQ8xEWjnBs


Currently, I am thinking more of the possible political implications, and what they will mean for the project.

Starlink could make attempts of governments to control the internet access of their citizens pointless.
Since information control is a critical part of how China and other regimes keep control, I doubt that they will let Musk just take away their monopoly on what is acceptable online and what is not.

I fear that SpaceX is going to be the trigger for a Space War.
 
Or maybe their control is being eroded now, and the last step will be accepted as inevitable.

hmm, are they merely cell towers in space? Cell phones will suffice? Or is special hardware needed for the consumer? Hardware is easier to control?
 
casebro said:
Or maybe their control is being eroded now, and the last step will be accepted as inevitable.

hmm, are they merely cell towers in space? Cell phones will suffice? Or is special hardware needed for the consumer? Hardware is easier to control?
Click to expand...

you'll need a pizza-box sized antenna.
So yeah, China might demand that all units sold domestically have a build-in Great Firewall.
Doesn't mean that local will only use those< and China would have no way to check traffic.
 
Last edited:
I think that it will be interesting as we get wave after wave of these new micro satellites, not just Star Link. What will the risks be after we say have a million of them up there, will it make launching more of a challenge?
 
I know there's some concern for astronomers. 12,000 new satellites might wreak havoc with time-exposed pictures.

But I'm not sure they would be all that intrusive. Given the size of the orbiter, its orbit height, and the general distribution (assuming it is even), how many could be seen at any one time? It seems like an interesting math problem but I don't know how to compute the cone of visibility for a single satellite.
 
The Great Zaganza said:
you'll need a pizza-box sized antenna.
Click to expand...
I guess that the Starlink (etc) folk have totally open specs on what's broadcast (comms protocols, frequencies, etc). If so, then the market for receivers should be very open. I wonder if there are estimates of likely retail prices?

So yeah, China might demand that all units sold domestically have a build-in Great Firewall.
Doesn't mean that local will only use those< and China would have no way to check traffic.
Click to expand...
I wonder if a built-in Great Firewall is even possible. Seems to me it would require quite a lot of memory and some serious CPU ... the actual GF is huge server farms :D
 
alfaniner said:
I know there's some concern for astronomers. 12,000 new satellites might wreak havoc with time-exposed pictures.

But I'm not sure they would be all that intrusive. Given the size of the orbiter, its orbit height, and the general distribution (assuming it is even), how many could be seen at any one time? It seems like an interesting math problem but I don't know how to compute the cone of visibility for a single satellite.
Click to expand...

There's been a lot of FUD and outright nuttery about this, the worst claiming that it'd cause light pollution that would ruin stargazing and describing their horror at seeing a few points of light in the sky and fury that SpaceX would dare do this without consulting anyone (despite the plans having been quite open, and SpaceX actually working with astronomers to minimize interference).

The reality is pretty much as you described: only a handful of Starlink satellites will be high in the sky at any given time, and they will become less visible as they gain altitude and orient with their solar panels "behind" them as seen from Earth. The satellites from the first launch are already much more difficult to observe. They will be an minor issue for a small percentage of long-term exposures.
 
JeanTate said:
I guess that the Starlink (etc) folk have totally open specs on what's broadcast (comms protocols, frequencies, etc). If so, then the market for receivers should be very open. I wonder if there are estimates of likely retail prices?
Click to expand...

The pizza box is a two-way phased array that electronically switches from satellite to satellite in a constellation of thousands as they move overhead, requiring intimate knowledge of their orbits and inter-satellite routing. There aren't standards for this sort of thing.


JeanTate said:
I wonder if a built-in Great Firewall is even possible. Seems to me it would require quite a lot of memory and some serious CPU ... the actual GF is huge server farms :D
Click to expand...

All you'd have to do is route traffic from Chinese terminals through the those server farms. The main problem for Starlink would be the concentration of traffic from across China through those satellites with ground links to the Great Firewall servers. And latency would suffer, of course.
 
cjameshuff said:
...

The reality is pretty much as you described: only a handful of Starlink satellites will be high in the sky at any given time, and they will become less visible as they gain altitude and orient with their solar panels "behind" them as seen from Earth. The satellites from the first launch are already much more difficult to observe. They will be an minor issue for a small percentage of long-term exposures.
Click to expand...

Isn't the degrees apart mentioned in the OP link ? Or somewhere... Altitude, sphere diameter, sphere area, divide by 12,000= area per sat, trig degrees apart?

Whatever, time to sell your ATT and Sprint stock?
 
Thanks. I think I have some significant misunderstandings on this.

cjameshuff said:
The pizza box is a two-way phased array that electronically switches from satellite to satellite in a constellation of thousands as they move overhead, requiring intimate knowledge of their orbits and inter-satellite routing. There aren't standards for this sort of thing.
Click to expand...
If the receiver includes GPS, the (very!) local position and time are a piece of cake.

Satellite orbits are “just” some spherical geometry and Kepler’s third (or equivalent); initial values are a big problem of course.

Very little memory or CPU needed for any of that.

What am I missing?

All you'd have to do is route traffic from Chinese terminals through the those server farms. The main problem for Starlink would be the concentration of traffic from across China through those satellites with ground links to the Great Firewall servers. And latency would suffer, of course.
Click to expand...
Right.

As I understand it, there’s no need for any particular terrestrial component ... your receiver can connect - via a network - to the internet via any of many ground stations, not just GF ones (in China or elsewhere).
 
JeanTate said:
If the receiver includes GPS, the (very!) local position and time are a piece of cake.

Satellite orbits are “just” some spherical geometry and Kepler’s third (or equivalent); initial values are a big problem of course.

Very little memory or CPU needed for any of that.

What am I missing?
Click to expand...

It's not a matter of CPU or memory usage. The terminals have to be tied into the system to get constant updates on the satellite locations, have to route across the constellation to another downlink (in the initial version, just a hop off the satellite, but with optical inter-satellite links in the later versions), switch that routing around as the network geometry changes including changes in surface to orbit hops at both ends, etc. And you also need a phased array transceiver that can switch almost instantly between satellites and likely handle signals from multiple satellites simultaneously, something that is going to require quite a bit of specialized, high-performance, and very application-specific signal processing.

There are no standards for any of this because nobody's ever done this before. There's a substantial amount of new engineering involved.


JeanTate said:
As I understand it, there’s no need for any particular terrestrial component ... your receiver can connect - via a network - to the internet via any of many ground stations, not just GF ones (in China or elsewhere).
Click to expand...

There's no technological reason you couldn't connect from a terminal in China to any other location. That doesn't mean the software has to permit it. The routes taken by traffic from a US-licensed terminal in a US embassy and a Chinese-licensed terminal in a coffee shop across the street might be completely different.
 
alfaniner said:
I know there's some concern for astronomers. 12,000 new satellites might wreak havoc with time-exposed pictures.

But I'm not sure they would be all that intrusive. Given the size of the orbiter, its orbit height, and the general distribution (assuming it is even), how many could be seen at any one time? It seems like an interesting math problem but I don't know how to compute the cone of visibility for a single satellite.
Click to expand...


I think it will spell the end of earth based astronomy.

https://www.theverge.com/2019/5/25/...tellites-video-dr-marco-langbroek-netherlands

This is 60 of them. 12,000 will light up the night sky to the point where constellations will be unrecognisable.


Still, progress, eh?
 
There is a risk to astronomy due to Starlink, because they fly so low.
But since their movement is so predictable, it should be possible to compensate.
 
Dancing David said:
I am not so sure about that:
https://www.skyandtelescope.com/observing/spacex-launches-starlink-satellites/

They seem to say they are often dim and right at the edge of eyeball visibility
Click to expand...

I wouldn't claim to be an expert and I hope you're right, I just suspect yhat there will be unexpected consequences for amateur astronomers.



The Great Zaganza said:
There is a risk to astronomy due to Starlink, because they fly so low.
But since their movement is so predictable, it should be possible to compensate.
Click to expand...


Which is fine if you have the tech to do that sort of thing. If you're just using a home telescope to interest your child in astronomy for the first time, I imagine it's going to be utterly infuriating to have these things crossing your view at amazingly regular intervals.
 
3point14 said:
I wouldn't claim to be an expert and I hope you're right, I just suspect yhat there will be unexpected consequences for amateur astronomers.






Which is fine if you have the tech to do that sort of thing. If you're just using a home telescope to interest your child in astronomy for the first time, I imagine it's going to be utterly infuriating to have these things crossing your view at amazingly regular intervals.
Click to expand...

I'm trying to some maths... so earth is made up of around 200 million square miles, since these will be at some altitude (though there are 3 layers so calculating it is tough), there is actually more square miles of area up there. But even just taken at the ground, that is one satellite per 16,000 square miles. A decent amateur telescope is showing 1 square arc second. There are 648,000^2 square arc seconds of sky. So the odds of a skylink sat being in your field of vision at any given time is... so minimal I'm afraid to even calculate it. Someone correct my math?
 
lobosrul5 said:
I'm trying to some maths... so earth is made up of around 200 million square miles, since these will be at some altitude (though there are 3 layers so calculating it is tough), there is actually more square miles of area up there. But even just taken at the ground, that is one satellite per 16,000 square miles. A decent amateur telescope is showing 1 square arc second. There are 648,000^2 square arc seconds of sky. So the odds of a skylink sat being in your field of vision at any given time is... so minimal I'm afraid to even calculate it. Someone correct my math?
Click to expand...


That's reassuring. I am probably unreasonably suspicious of this in terms of impact on the night sky. (In terms of communications technology, this is very impressive and should last the rest of human history (about 75 odd years)
 
Thanks.
cjameshuff said:
It's not a matter of CPU or memory usage. The terminals have to be tied into the system to get constant updates on the satellite locations, have to route across the constellation to another downlink (in the initial version, just a hop off the satellite, but with optical inter-satellite links in the later versions), switch that routing around as the network geometry changes including changes in surface to orbit hops at both ends, etc. And you also need a phased array transceiver that can switch almost instantly between satellites and likely handle signals from multiple satellites simultaneously, something that is going to require quite a bit of specialized, high-performance, and very application-specific signal processing.

There are no standards for any of this because nobody's ever done this before. There's a substantial amount of new engineering involved.
Click to expand...

That's part of what I was missing.

However, it is surely in Starlink's interests to make the protocols etc as open and standardized as possible, isn't it? Doing so would give them first mover advantage (and making it more difficult for a competitor to introduce a quite different standard), as well as encouraging the manufacture of pizza boxes.

There's no technological reason you couldn't connect from a terminal in China to any other location. That doesn't mean the software has to permit it. The routes taken by traffic from a US-licensed terminal in a US embassy and a Chinese-licensed terminal in a coffee shop across the street might be completely different.
Click to expand...
Right.

And having terminals not licensed by China, in China, could be made some kind of punishable offense. Like what was (once?) tried with satellite dishes.

I wonder what %-age of the world market for Starlink terminals Chinese manufacturers will end up with?

Unrelated question: how do you connect your fave internet device - tablet, smartphone, PC, ... - to the terminal? Ethernet cable? Bluetooth? And presumably you'd encourage up to a household's worth of such connections, or maybe even a small apartment building's worth (ground floor residents may find it challenging to "see the sky").
 
The Great Zaganza said:
There is a risk to astronomy due to Starlink, because they fly so low.
But since their movement is so predictable, it should be possible to compensate.
Click to expand...
Maybe, but I doubt that it would be easy.

And some astronomy facilities will be hit far harder than others.

Any Starlink satellite - in sunlight! - will be screamingly obvious to any contemporary optical survey, should it cross the field being observed ... after all, geosats are very easily spotted by even SDSS, much less the Subaru HSC or the future LSST.

I suspect the hardest hit will be the LSST, closely followed by the large field supernova hunters.

Trivia: when PanSTARRs was being designed, the US DOD was very concerned that it would "spot" all manner of secret missions, and may have succeeded in getting the consortium to somehow censor their data (if in sunlight and in the field being imaged, all satellites bigger than a metre (from memory) would leave a very clear trail). I think they learned to stop worrying, not least because the Russian and Chinese (say) military were more than capable of finding and imaging the DOD satellites on their own.
 
Aside from the initial cost of the antenna what is the monthly/daily data usage fee going to be? I really don't think it will alter coverage in most of the populated areas, but will be usable in areas that have sparse cell towers currently.
 
3point14 said:
I think it will spell the end of earth based astronomy.

https://www.theverge.com/2019/5/25/...tellites-video-dr-marco-langbroek-netherlands

This is 60 of them. 12,000 will light up the night sky to the point where constellations will be unrecognisable.


Still, progress, eh?
Click to expand...

Absolute nonsense. 12000 satellites, spread around the entire earth, will mean an average of one for every 16400 square miles of earth's surface. There will never be anything like that "train" of 60 except right after they launch. In operation they will be higher altitude and a different orientation and you will have a hard time even seeing one of them.
 
phunk said:
<snip> In operation they will be higher altitude and a different orientation and you will have a hard time even seeing one of them.
Click to expand...
Unless your telescope has a diameter of 8m (or even 2m), and your detectors are state-of-the-art CCDs.

OTOH, if your telescope is in Antarctica ... ;)
 
Dancing David said:
I am not so sure about that:
https://www.skyandtelescope.com/observing/spacex-launches-starlink-satellites/

They seem to say they are often dim and right at the edge of eyeball visibility
Click to expand...

Association of Universities for Research in Astronomy on the topic:
https://www.aura-astronomy.org/news/aura-statement-on-the-starlink-constellation-of-satellites/

"In the case of the full constellation of Starlink satellites, initial calculations show that LSST images would, on average, contain about one satellite trail per visit for an hour or two after sunset and before sunrise. A very conservative upper limit on the number of LSST pixels affected by Starlink satellites is about 0.01%, and quite likely smaller. Therefore, for LSST, even a constellation of about 10,000 Starlink satellites would be a nuisance rather than a real problem."
 
lobosrul5 said:
I'm trying to some maths... so earth is made up of around 200 million square miles, since these will be at some altitude (though there are 3 layers so calculating it is tough), there is actually more square miles of area up there. But even just taken at the ground, that is one satellite per 16,000 square miles. A decent amateur telescope is showing 1 square arc second. There are 648,000^2 square arc seconds of sky. So the odds of a skylink sat being in your field of vision at any given time is... so minimal I'm afraid to even calculate it. Someone correct my math?
Click to expand...

The first phase has 24 equally spaced planes at 550 km altitude with 53 degrees inclination, containing 66 satellites each...5.45 degrees apart within each plane. Each will be 660 km from the preceding and next satellite in its plane, so two satellites will be about 60 degrees apart seen from the ground when their midpoint passes overhead...120 lunar diameters.

There will be several of those planes crossing the sky at higher latitudes, but that's still several orders of magnitude short of the more ridiculous claims. And just think about it: why do they need so many satellites to provide internet access? Because in LEO, for any given location on Earth's surface, most of them are going to be below the horizon! There's a weird sort of pseudo flat-eartherism in the more overwrought complaints, as if there's only one sky and everything in it will be visible everywhere.

Additionally, in the summer, near the poles, they will be in sunlight most or all of the night, but the rest of the year they will be in Earth's shadow except near sunrise and sunset, and quite invisible.
 
3point14 said:
Oh, relax. I'm still gathering data.
Click to expand...

Perhaps...just a thought...do so before making absurd claims?

Not that it actually takes any additional data, a few seconds of thought suffices to show that your claim that "12,000 will light up the night sky to the point where constellations will be unrecognisable" is physically impossible.
 
bknight said:
Aside from the initial cost of the antenna what is the monthly/daily data usage fee going to be? I really don't think it will alter coverage in most of the populated areas, but will be usable in areas that have sparse cell towers currently.
Click to expand...

For the base rate, probably quite low - and remember that multiple people can use it at the same time.
SpaceX will most likely run a Premium system for users requiring maximum speed, such as HFT trading software, and make them pay for it.
If you are willing to accept slower rates you will pay a lot less.
 
cjameshuff said:
Perhaps...just a thought...do so before making absurd claims?
Click to expand...

Good god no. Why would I do that. I actually wanted an answer and, on the internet, the best way to do that is to do what I did.

Thank you for your input.


Not that it actually takes any additional data, a few seconds of thought suffices to show that your claim that "12,000 will light up the night sky to the point where constellations will be unrecognisable" is physically impossible.
Click to expand...

Now I know that. Then I didn't. Seems to be working quite well so far. :D
 
The Great Zaganza said:
For the base rate, probably quite low - and remember that multiple people can use it at the same time.
SpaceX will most likely run a Premium system for users requiring maximum speed, such as HFT trading software, and make them pay for it.
If you are willing to accept slower rates you will pay a lot less.
Click to expand...

In other words, they haven't announced a pricing structure. I agree it will be less if slower speeds are acceptable. But this is really structured for those that don't have for those wo don't have any coverage currently.
 
3point14 said:
Good god no. Why would I do that. I actually wanted an answer and, on the internet, the best way to do that is to do what I did.



Thank you for your input.









Now I know that. Then I didn't. Seems to be working quite well so far. :D
Click to expand...
How dare you ask about something you don't know!
 
Dancing David said:
I am not so sure about that:
https://www.skyandtelescope.com/observing/spacex-launches-starlink-satellites/

They seem to say they are often dim and right at the edge of eyeball visibility
Click to expand...

I read that article. It doesn't seem to say that at all. Here's what it says on the issue:

A Million Points of Unwanted Light?
Although the sight of five dozen satellites in a row will take your breath away, not a few of us are concerned about the volume of traffic over our heads. Yes, there's a lot of space up there. We get it. But in 9 years, when 12,000 of them will be crawling the skies like so many ants, will it detract from the sight of the stars at night? Some will say that most of the units will be too high to see with the naked eye, and my May 28th observation seems to be proving the point, but that lowest and most populated belt — the 7,500 at 340 kilometers altitude — will almost certainly be visible. Not just in bright twilight either. My May 25th sighting was made at 11:25 p.m.

If you're an astrophotographer, trails from Starlink may be unavoidable and require frequent and deft use of your photo program's cloning tool. For professional astronomers, imaging headaches undoubtedly lie ahead. For the visual observer, will it mean a constant reminder of machines on parade while seeking the solace of a dark sky?

In response to online concerns from amateur and professional astronomers, planetary astronomer Alex Parker tweeted his concerns that "If SpaceX launches all 12,000, they will outnumber stars visible to the naked eye," and estimates that "at midsummer midnight in Seattle about 500 of them will both be above the horizon and directly illuminated by the Sun."
Click to expand...
 
cjameshuff said:
Perhaps...just a thought...do so before making absurd claims?

Not that it actually takes any additional data, a few seconds of thought suffices to show that your claim that "12,000 will light up the night sky to the point where constellations will be unrecognisable" is physically impossible.
Click to expand...

I think "constellations will be unrecognisable" was hyperbole.

Having some concern about the implications for stargazers of having 12,000 new satellites, at least 7,500 of which, according to the article I quoted, will be visible to the naked eye.
 
The reason why SpaceX was granted permission to put so many satellites into orbit at all was that they are capable to decelerate on their own to burn up in the atmosphere with very little debris left.
Given the pace of technology, current tech Starlink satellites have probably less than 20 years of operational life anyway.
So the problem is temporary.
 
The Great Zaganza said:
The reason why SpaceX was granted permission to put so many satellites into orbit at all was that they are capable to decelerate on their own to burn up in the atmosphere with very little debris left.
Given the pace of technology, current tech Starlink satellites have probably less than 20 years of operational life anyway.
So the problem is temporary.
Click to expand...

Just two comments. First, I'm actually very excited about this. I think it's a great thing. I just think we shouldn't dismiss concerns out of hand when there do seem to be some legitimate issues.

Second, regarding your comment, I understand that the specific satellites being put up now will have a limited life and can be deorbited without problem. But I also doubt that once Starlink is up and running they'll stop the project entirely. Old satellites will be replaced with new ones. Maybe those new ones will be placed in a higher orbit if concerns with being too visible become an issue, and maybe something else will be done (they are already talking about making them less reflective). On the other hand, once the thing is up and running we may simply end up with a new normal that is unlikely to be changed. If starlink becomes a popular choice as an internet provider, people are unlikely to give that up because a few stargazers are unhappy with it.

So I don't think the issue is as temporary as you suggest.
 
Sure, if the concept works, it will become a fixture - but as you said, future versions might be designed to minimize the visual impact.
What won't happen is that the satellites will be move to a higher orbit - the opposite is more likely: sending the signal up and down is the most significant delay in the system, and the clear goal is to be faster than terrestrial solutions.

And yes, I do think that as space launches get cheaper, a number of artificial "shells" of stations and satellites is inevitable, and if nothing else, Musk is wise to get squatter's rights in this orbit before others are ready.
 
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