The article covers the mitigations already in place and how they only partially resolve the issue. These satellites are low, bright (at dawn/dusk) and very soon to be incredibly numerous.
Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three companies from one country.
This is cost turned into an "externality" and foisted upon astronomers--at every scale of investment--all over the world. Stock holders in these companies won't pay for it, but tax payers everywhere will pay for the mitigations. Not cool. This is a hill I'll die on.
I personally believe that pervasive high speed internet even in remote locations will do more for humanity than the scientific cost of these satellites.
However, this conversation has basically been skipped over. Maybe you're right and I'm wrong.
The constellations are being launched, and there's zero chance of shutting them down once they're serving a commercial role. Considering the abundant red tape in the modern world, it does seem like it was a little thin on the ground here.
> I personally believe that pervasive high speed internet even in remote locations will do more for humanity than the scientific cost of these satellites.
I've had faster Internet than the average Starlink speedtest says, in rural Romania, at the foot of a mountain, wild bears and all: https://twitter.com/q3k/status/1172621386977861632 . Internet access in rural areas is pretty much a solved problem, it just now hinges on enough of a societal push to apply this solution where needed.
Starlink is yet another SV-style attempt to solve (US) societal problems by blindly applying technology. Except this time, this also affects other countries, and we're furious.
I've been there, it's beautiful. Although under ten kilometers from a town of tens of thousands wasn't exactly what I had in mind; I was picturing some of the places I've been in Africa that don't have mobile reception and may well never get it if it means laying fiber. A solar powered base station that relayed mobile internet, even if slow, would make a meaningful difference.
The point of my comment isn't to defend the satellite launches, quite the opposite.
It's saying that even as somebody that would be in favor, not carefully considering the trade offs before giving permission to permanently alter the night sky is not acceptable. This is exactly the kind of thing that bureaucracy should make painfully slow.
> I was picturing some of the places I've been in Africa that don't have mobile reception and may well never get it if it means laying fiber.
When was the last time that you were in Africa? And in which country, because it's an entire continent.
EDIT: So I guess HN doesn't like being called out on https://africasacountry.com/ issues? Well sorry not sorry, but as someone born in Ghana I'm more a little tired of the sentiment on display in the cited part of comment I'm reacting to, which is the implication that Africa as an entire continent is inherently and forever will be a place too poor to have proper infrastructure.
This isn't about being able to afford infrastructure. It's about population density in rural areas.
North America and Australia (where I'm from) have the exact same issue. No country is going to spend a million bucks to lay fiber to ten person towns in the middle of nowhere.
>> No country is going to spend a million bucks to lay fiber to ten person towns in the middle of nowhere.
Why not? It has been done before. Every developed country went through a period of rural electrification whereby schemes were developed to encourage and/or force electric companies to run wires out into the rural farmland. Internet is the modern analogue for electrification. Those same approaches would work equally well for fiber.
The American approach: "The Rural Electrification Administration (REA) was created by executive order as an independent federal bureau in 1935, authorized by the United States Congress in the 1936 Rural Electrification Act, and later in 1939, reorganized as a division of the U.S. Dept. of Agriculture. It was charged with administering loan programs for electrification and telephone service in rural areas. Between 1935 and 1939 – or the first 4½ years after REA's establishment, the number of farms using electric services more than doubled"
Large scale infrastructure is no longer possible in the US for all kinds of reasons. But you can't just compare infrastructure projects from the 1930s and pretend it will work. If you had to build the interstate highway system, or transcontinental railroad, or Hoover dam today, it would take decades and cost many times the price in real dollars.
Funny, Canada, even less dense, is doing exactly that. Maybe not 10, but at multiple levels of government there have been up to half the capital without many strings attached to get broadband out to rural areas. My understanding though, it's not work the time even with the fibre there for the larger companies in many cases. This is the latest program https://www.canada.ca/en/radio-television-telecommunications...
I know of at least some of the communities on the James Bay coast recently got fibre service and I think others along the Northern coast of Canada, along anecdotally several others in rural Ontario.
I am talking about money already spent and delivered, not future project that will probably be delivered on.
The U.S. actually does do this! The FCC alone spends more than $2bn annually subsidizing telecom infrastructure in rural areas. There are a number of other similar programs, and Ajit Pai (current FCC chairman) recently proposed another $20bn of spending on subsidies for rural internet connections: https://www.fcc.gov/document/fcc-proposes-204-billion-rural-...
If we're talking about population density in rural areas, then the poor countries of Africa (excluding Saharan desert) have a much higher rural population density than middle of USA, and there rolling out cell coverage is quite feasible, definitely more feasible than rolling out an electricity grid - there's already something like a hundred million people in sub-Saharan Africa who don't have electricity connections but do have mobile phones and coverage.
Because I've been to the Sahara desert and it's the most remote place I've ever been. I experienced the gaps in coverage first hand.
There are equivalent places in central Australia, but even though I grew up here I haven't been more than a few hours drive away from the coasts.
I haven't been to North America. Russia didn't cross my mind, but I haven't been there either.
This isn't to say I don't have warped perspectives or prejudices about Africa. I didn't realize the population density is that high in the south, where I haven't been.
Western media only discusses African countries when things go wrong. The only people I know from there are three white families who left South Africa. If you asked me to draw a map of the countries it would be my worst continent.
The original post though really was just based on my personal experience with remoteness.
I believe you, thank you for engaging with my questions in a civil manner (I can't say the same for the way people initially downvoted my questions, but that isn't your fault of course - I hope it was clear that the "you guys" in my previous comment referred to them).
I think asking why I said Africa and not the specific country or region is fair. Had I traveled there instead, would I have said North America or Alaska? Would I have said Russia or Siberia? I'm not sure.
For what it's worth an initial rush of downvotes (or upvotes) is fairly common on HN; I'd ignore them for the first hour or so. After that you'll probably have a fair idea of the HN consensus (fickle as it is).
People that really care about an issue will sit there and refresh a thread constantly, so in the short term you're mostly knowing what they think about your comment. But they can't vote more than once.
My first comment in this tree was downvoted to -3 within two minutes of posting, but now sits at +40. I actually wasn't sure at first whether it was being downvoted by people for or against Starlink et al. Maybe both.
Would you have had a second thought if someone said "Some of the places I've been in North America don't have great reception"? OP never claimed or implied Africa was a country.
Except they could have been referring to the continent. "some of the places" could refer to different places in different African countries, hence "some"; and doesn't imply all, everywhere, or "forever" in Africa.
> Starlink is yet another SV-style attempt to solve (US) societal problems by blindly applying technology. Except this time, this also affects other countries, and we're furious.
Perhaps you are. I'm from the same country, and I couldn't be happier :).
I mean, LEO Internet constellations are awesome for providing access (not just in rural areas, but also in remote areas and at sea). But more than that, we're talking Starlink here in particular. The problem it's solving isn't (just) how to improve Internet access for some people. The main problem it's solving is how to fund SpaceX's R&D on Starship. Which translates to dropping another order of magnitude from the cost of access to orbit. Which will, longer-term, translate to a boon for astronomy.
I remember being on a tour in Romania in 2019 on a bus and in the middle of a forest in Transylvania and a colleague called that they have some issues at work and if I could please look into it. Then I just tethered my LTE reception (sometimes it dropped to 3G but was still usable) to my laptop, SSHed in and fixed the issues for them.
In Germany, even being on a quite populated beach some 500 meters away from the promenade of a popular vacation city (Heringsdorf) is a hit or miss in regards to a usable mobile reception not even talking about LTE (this is on O2 Deutschland, in August 2020). There are many parts of Germany, that are more or less white spots in regards to a usable mobile data connection. I mean, sometimes my phone would just use the polish signal from Świnoujście even though Heringsdorf is about 10 km from the border.
There isn't anywhere in Europe that's "rural" by the standards of North America.
The North Slope Borough in Alaska is nearly the size of Romania, but has only about 9,000 people living there. The state as a whole is larger than all of Western Europe, but has only about 700,000 people.
"There's food in my refrigerator. Ergo, world hunger is pretty much a solved problem."
If we are just going to completely ignore costs, then I can say that getting great astronomical observations is solved as well, since we can just launch satellites to take the observations instead of doing ground-based observations. So it's not clear what the big deal about these satellites is anyway.
Romania is an outlier when it comes to internet speed.
But I know people from rich countries like UK, US, Germany with download speeds under 5 mbps paying more than you would pay for the most expensive line on Romania.
So it's not exactly a good potential userbase for starlink. However, most of South America, Africa and Central Asia could benefit massively from Starlink and start participating in the global digital economy
> I personally believe that pervasive high speed internet even in remote locations will do more for humanity than the scientific cost of these satellites.
Perhaps in the US, but other countries, even poor ones, manage to do rural internet fine without cluttering the night sky.
I, for one, am not stoked about the implications of an American ISP forcing worldwide coverage for themselves. Their shady business practices and the questionable reliability of the US government make it very hard for me to see many upsides.
Were this to be released only in remote areas and third-world countries, I would agree that there is a large net benefit to Starlink. However, because of the way the system is designed, every country on the planet will now be forced to deal with a solution for the anti-competitive behaviour of the American ISP market.
As long as Starlink is managed by a an American company, I have little faith in their intends and purposes. Being able to intercept or duplicate random internet communications worldwide seems like an NSA wet dream come true to me.
Current mitigations (visorsat) by SpaceX already make the satellites completely invisible to the naked eye. It’s less of a visual impact (zero once deployed) than any other visible LEO satellite or air travel. Celltowers high enough to need a light are highly visible and are a much greater visual impact than Starlink.
>Perhaps in the US, but other countries, even poor ones, manage to do rural internet fine without cluttering the night sky.
Most of sub-saharan Africa has slow and expensive internet. I would guess there is 1 billion people who will have access to the internet via mobile tower with starlink & competitors backhaul in a few years. This is enormous.
The same countries also have nationalized internet service providers, often run by friends or family of the government. I doubt it'd be legal to sell StarLink receivers in large parts of the continent.
There's nothing in the landscape that prevents Africa from running fiber to every house like Eastern Europe has been proven to be capable of. In fact, a lot of infrastructure is already there. Geopolitical instability, poverty and instability of the power grid makes it very unattractive to build data centers in the continent and that's what's forcing ISPs to use expensive cables to access most websites, driving up the cost and reducing the speed.
This problem can be partially mitigated by using StarLink instead of oceanic cables, but I don't imagine their system will be able to replace the fiber optics that carry most large volumes of data between governments. StarLink is fast, but still depends on ground stations for decent speed internet access. Collecting internet traffic for one entire continent on another isn't feasible in the plans I've seen.
StarLink will reduce latency and improve coverage for customers already using satellite internet connections. African people can already use those if they have the means to afford it, yet many African cities have dial-up or slower internet access because of the lack of resources.
India has banned most satellite telephones [1] (Inmarsat is still allowed apparently) and still catches people using them. There's a more complete list at [2].
Musk has already admitted that providing satellite services to countries like China can become a problem [3]. Countries that don't want StarLink and don't have the capabilities to take out LEO satellites might start to team up with China, Russia and other countries that do to protect their sovereignty.
Of course there's no way to prevent hardware that someone managed to sneak in from connecting to the satellites. Those devices will all need to come from the black market though, severely limiting the reach and future business StarLink might have in such a country.
Few nations, especially in Africa, have the sort of control over the sale of small electronics that is envisioned here. One would hope that the monopoly providers wouldn't invest many resources in policing areas they don't even serve... Musk probably isn't relying on any one particular nation to validate his business plan.
On top of the points made by q3k, about this being a US centric issue, being projected as a global issue, why do you believe this implementation will be able to deliver global pervasive internet?
The obejective is noble but can you provide any realistic data or estimates of how this infrastructure can scale to more than a few million users and _still_ be high bandwith. Beyond that your bandwith will go down as you add more users.
The only use-cases that this serves are high-income people that want to go off-grid but are unwilling to sacrifice high-bandwith, and military deployments (which SpaceX does not hide as an objective).
This (it’s only for rich people) is silly. North Carolina officials are already planning for Starlink terminals to provide rural internet hotspots to help with folks who need good internet due to COVID-19 school closures.
Actual rich people can afford to put in fiber or line of site wherever they are. $100,000 or whatever, doesn’t matter. This is for the regular people in rural areas.
Seriously, has no one making these claims ever talked to someone whose best internet is geosynchronous satellite? Do they think only the very rich live in rural areas?
> On top of the points made by q3k, about this being a US centric issue, being projected as a global issue, why do you believe this implementation will be able to deliver global pervasive internet?
Rural internet access is absolutely not an US-centric issue, many parts of the world have much worse infrastructure. Being opposed to new technologies because "I already have fast internet" is unbelievably narrow minded.
1) Why do you think people in subsaharan Africa, for example, won't be able to use it?
2) The only limitation on bandwidth (and thus users) is the number of satellites in orbit. If the constellation bandwidth is saturated, launch more satellites and you get more bandwidth.
3) I guess you'll just ignore the use cases for the tens of millions of non-rich people who literally can't get decent internet because it doesn't exist where they live?
Is there any expectation that a local in Africa or sea would be able to afford starlink rates? I haven't seen pricing information yet, but I'd be very surprised if that was the case.
If it was dirt cheap, I'd probably jump at it. My Netflix streams the usual pablum using about 5% of the 50mb/s fibre at my house. As for phone plans, electricity and other near "utilities" it doesn't do the vendor any good if consumers actually understand their own needs. And don't get me started on megapixels!
You are might be right (though we could quibble over diminishing returns on speed over a few Mbps). But you seem to be discussing this as a choice.
One nation launching thousands of satellites because three companies want to make a pile of money and also because that one country can't get it's act together and do something about its own predatory cable companies seems like a weak argument to make from a moral point of view.
But what about third world countries and such? Summary opinion: The people who could afford Starlink already have broadband, and we wouldn't want to subsidize others access, would we? That path leads to socialism and the USPS. Or indeed broadband as a right attached to cable company's license. Impossible! (In that one country.)
Let third world countries sort out their own broadband and make their own money. And let them have their own view of the damn stars.
My personal idea is that Starlink is built for automated high speed stock trading across the oceans, because it reduces round-trip latency by some ten milliseconds. Light is much faster in vacuum, almost lightspeed, then in fiber. In fiber the speed of light is around 68% of light speed in vaccum. Giving "Internet to everybody" is just a marketing trick. People who maybe could need internet for social reasons cannot afford Starlink, that is for sure.
> I personally believe that pervasive high speed internet even in remote locations will do more for humanity than the scientific cost of these satellites.
If the internet was simply a wellspring from which one could obtain knowledge you may be correct.
But most likely, the internet will instead be used to proliferate bigoted and intolerant opinions, while spreading lies and misinformation in the form of crude memes. As the last of human populations without high speed internet comes online, they will expand their capacity to inflict harm at speeds never before seen.
I’m afraid you will die on that hill and be replaced by a happy rural resident who was being abused by a local telco monopoly, but is now using competitively priced, fast, low latency satellite internet.
Using keps and scrubbing exposures in post is something we could already do decades ago. It’ll just be a new part of the workflow and eventually the space NIMBYs will quiet down.
Spaceships and radio waves are cool and provide a unique solution.
Let’s not pretend this was the one true way to get around Comcast et al’s stranglehold though. That problem could have been solved politically with regulation plus (in the countryside) ground based radio, or (in cities) with regulation of cable infrastructure such that it was separated from packet-routing and customer-service.
If satellite ISPs genuinely are the solution to entrenched telcos then every streak of light in the sky is a testament to the failure to find a solution. We will look back and wish we had been able to achieve a system of sensible business regulation delivered by those elected to do so.
This should be the top comment. It’s an especially prevalent view in the USA that bad politics is a law of physics and the only solutions are madly technological. It’s not true as many other parts of the world prove. You can just have a not-insane ISP/telco regulatory system if you so choose. (see also healthcare, food/agricultural standards, water quality, online privacy... all choices).
> It’s an especially prevalent view in the USA that bad politics is a law of physics and the only solutions are madly technological. It’s not true as many other parts of the world prove. You can just have a not-insane ISP/telco regulatory system if you so choose. (see also healthcare, food/agricultural standards, water quality, online privacy... all choices).
I agree. However it's going to be a tough nut to crack because that belief is self-reinforcing. People who believe the government can't do anything right also seem to advocate policies that make the government more ineffective, which provides false confirmation of the initial belief.
Yes, you make a very strong point. It seems the highest bidders in the city were able to work with city planners to lay their cable lines... while in the rural areas (where I grew up) there were not enough customers to justify modernizing old telephone wire.
The response to COVID-19 has been an expectancy on equal access to Internet and either the telco gets to capitalize on their geographic monopoly or the rural folks get short changed with 1980s dial-up or GEO satellite link.
I don't think you really have any idea what it's like to live somewhere truly rural. Cable and DSL companies do not serve these places.
Ground-based radio requires line-of-sight to somewhere with both power and an uplink. Nevermind "third-world" countries - the vast majority of the United States, by square foot, does not have this. Rural wireless is incredibly dependent upon topography, many places will just never get it.
I live one hour from SF. I have rural wireless broadband (bounced off a solar relay I installed on a hill). It's terrible, but I'm still one of the lucky ones - most of the properties we looked at when shopping did not have this access, and the only internet option was Hughes.
I appreciate the counterpoint as part of this discussion, though I personally grew up on a rural fruit farm which is currently served by a wind turbine powered hilltop relay (~4Mbps long range WiFi) and copper cable DSL (~7Mbps.)
The valley is 400’ deep and has 50 copper pairs coming up the side, of which 20 come to the road the house is on, and 10 remain by the time you get to the family property. 3 more are taken by properties down the way, so 7 pairs (or ~50Mbps) lay unused. It would be interesting if the copper was changed to a 100% utilization rate.
The point though is there is power and copper telephone at the site. And a road! At some point, someone managed to invest in infrastructure for this house. In some sense it’s quite disheartening that the only modern equivalent to that kind of infrastructure investment is the spaceship endrun around the incumbents.
> That problem could have been solved politically with regulation plus (in the countryside) ground based radio, or (in cities) with regulation of cable infrastructure such that it was separated from packet-routing and customer-service.
My hope is that these constellations put pressure on the ground based incumbents to fix their shit. The result might be that we get cheap enough internet on the ground that the constellations become unprofitable and shut down. Might be a win-win without politics and regulation.
> a happy rural resident who was being abused by a local telco monopoly
So you're straight up saying that because the regulation of US telco companies is ineffective and/or corrupt, the entire planet should pay for it? That's your argument? Please tell me that's not your argument.
I invite you to read astrophysician's comment on this idea -- https://news.ycombinator.com/item?id=24144959 and in fact browser his/her other comments on the topic. Summary: It is not that simple and assuming it is is not a good look!
Most decisions, including where you live, come with some upsides and some downsides. Rural residents in developed countries made their choices. They accepted having less infrastructure than more densely populated areas in exchange for other factors. If they valued high speed internet that highly they would have made a different choice.
As I noted on a similar thread the issue is not removing the streaks, it's what data is lost behind those. If you take a look at this image you'll see that it can be a non-trivial amount of interference in some cases and that data can't just be filled in with "black". https://i.imgur.com/Qdt0N2g.png The interference also causes a "glow" effect on the CCD which corrupts the data well beyond the edges of the main streak as well.
I love all of the comments about using software to filter out the images. This response is so obvious that it is from someone who has never worked with data from imaging the sky, and probably have never thought about it more than a drive-by comment. "Just filter it out" they say. And replace it with what? An average of near by pixels? An AI background replacement? That's just bollocks. Every single dot in the sky is another star, galaxy, planet, asteroid, etc. They are not blemishes in the image. To just write them off would be like drawing a map of the earth without New Zealand on it.
To reinforce this, there is a fair bit of astronomy that is looking for single photon differences. The optics and engineering here is very cool (pun intended) and can take months of time on an instrument to detect, if there is anything at all. Sources of noise are pathologically chased down. Adding in noise would be like trying to chop off your arm, easy to do once, but hard to undo.
As a reminder, astronomy is not as much about the 'image' as it is about the 'measurement'. Editing pictures like in Insta is not the point here, you can't fill things in.
Exactly. Modern day comet/asteroid hunters are taking images from night after night and treating them like time lapses to see what dots are moving. Removing these dots to fill in the void left by the satellite streaks sets this method of detection back to unusable/unreliable. Even filling in the removed satellite streaks in an image with data from previous/next images totally invalidates the tracking of objects in motion.
.. and I have given up chasing down the 'JuSt UsE SpaCE teLeScoPEs' comments. These people would write off the loss of New Zealand as the market simply finding the right benefit-cost ratio.
Remember, astronomy images generally have long exposure times, which already involve tracking the sky, and then averaging out values in the exposure across minutes/hours/days/whatever.
A satellite passing over a point in the sky means that area of sky is affected for only a tiny fraction of the total exposure. As long as you have a database of all satellite locations, you just don't include data from those time slices in the final average. Or if you don't know where satellites are in advance, you just do basic outlier detection -- the kind that already eliminates things like airplanes, birds, the ISS, etc.
Nobody's filling in anything with "black", and the area of satellite interference can be easily expanded to include the "glow" area.
In the end, the quality of the overall image is degraded by a tiny fraction of a percentage, which can be trivially overcome by extending the total exposure time by the same tiny fraction of a percentage.
I guess you could statistically impute that data. But it is the long tail of unlikely readings which are generally interesting, and imputation will not find those.
This is a logic flaw I see everywhere. Making a proposition for what might have been there is not a useful scientific instrument. And especially not when unseen anomalies are an integral part of pushing your field forward. If you're inferring what might have been there you're explicitly filling in based only on what you already know.
I agree, but isn't filing in what you already know a common technique when presenting things for human consumption? I'm thinking scanning microscopy, SEM, STM, etc.
The image implies that all the data is from the same instant, when it's not. Normally that's OK, but it's not always.
Unfortunately, the 'glow' is from the optics, not the CCD (you'd see streaks or 'boxing' that way). You can't statistically impute the optics, as these issues are based on physics. A good starter article here; http://spiff.rit.edu/classes/phys312/workshops/w10c/telescop...
It seems to be around 1-2%, which I would say is trivial. This can be further reduced if you use multiple exposures because then only 1 contains the streak. Getting satellite data from SpaceX about satellite positions and turning off the receiver for a few seconds would also mitigate the issue. I don't understand how this is treated as a problem that's worth halting satellite launches over.
In this sample image it's not just the white streak but the glow caused by it which extends about 5-8x it's width to either side. More like 20% of this image is unreliable data.
Taking multiple exposures isn't always possible, this may be a continuous multi-hour exposure. Additionally if you're looking for transients, NEOs, or star field mapping then there is definitely lost data that can't just be inferred.
The conversation isn't just about halting launches. It's about recognizing and working to mitigate the issue now before we get too far down this path.... and accepting that it's not a trivial "photoshop" problem.
You didn't say it's small, you said it's "trivial". This isn't about people taking pretty pictures, this is about people trying to do actual work. It doesn't matter if it's 1% or 100% if it still ruins what they're working on. So yes, you're being arrogant by saying that just because it's a "trivial" amount that's ruined, when you don't understand what they're doing.
2% is trivial. They lost 2% of information (as someone pointed out this might be closer to 20%). This means the cost to the astronomer was 2% (or 20%). Calling this "ruining" is an exaggeration. Of course it would ruin a pretty picture, but "This isn't about people taking pretty pictures, this is about people trying to do actual work." where you can choose the part of information you take into account.
If the entire field of astronomy is so educated on the subject, why do most not know Starlink was never visible except at dawn or dusk, and it’s already implemented successful mitigations for those tones with visors?
(1) astronomers are pretty darn aware of everything going on, and it's really shocking as an astronomer to see these sorts of claims. There have been close collaborations with Space X to try to mitigate some issues, but these are partial mitigations and the most important ones are only planned, not implemented. The "successful" mitigations I think you're referring to is their "DarkSat" coating, which is not actually a successful mitigation. It is still ~2x as bright as the ~maximum level of acceptable brightness for e.g. LSST.
(2) Space-X did not release any details about brightness characteristics, and they themselves claim that they were "surprised" by the brightness. To people that work in space rather routinely, that is staggeringly incompetent.
(3) > why do most not know Starlink was never visible except at dawn or dusk
Near earth object (NEO) detection only happens during these times. NEO includes "asteroids that threaten human life" so I would hope you agree that this is pretty important. Also, depending on latitude and time of year, "dawn or dusk" can constitute your entire observing window. So this doesn't really make things better.
(4) all of these mitigations should be done before companies can start doing ~10,000 satellite launches. The only reason this isn't done is outdated legislation that never conceived of this being possible.
SpaceX has just implemented sun Visors on the latest batch of satellites, so why aren’t you aware of that?
In space infrared detectors are the most effective way of searching for dangerous NEOs, and SpaceX has made them far cheaper to launch. How come you don’t know that?
How about looking at what the username of the person you replied to spells out. Then click on it, look through their comment history and do some homework.
I think you're mistaking "giving them carte blanche" for "highlighting one mistake they make in a long post containing a lot more information, context and nuance without acknowledging any of that in the slightest, and use that as if you caught them red-handed in a gotcha! that breaks down their entire argument".
I guess that's a specific version of the "cherry-picking data" fallacy.
Its not just about Starlink though, its about setting a precedent before every company and country starts launching competing constellations. When should we start to care after the first few thousand or after hundred of thousands of eventual satellite's?
CCDs are not really receivers that can be turned off for a couple seconds. A physical shutter moves in front of the detector and covers it (for most instruments as they exist right now).
Sure. And for small field of view things that might be the future.
But if you are looking at large chunks of the sky at some point with enough satellites the shutter will have to stay shut for the whole duration of the exposure.. so not really a good solution for that.
Shutters for astronomical instruments are specifically designed to open and close evenly, so that each pixel of the detector receives the same amount of exposure time (as good as is possible). Otherwise it becomes very difficult to calibrate the image, since some parts of the image received more light than others.
Even opening and closing the shutter multiple times during one exposure will cause issues - but probably still possible to get under control.
But covering parts of the detector will create significant variants that will be extremely hard to control for. Keep in mind we don't really want pretty pictures, but we use these images to measure the brightness of objects in those images (photometry).
(can't reply below)
If you had a localised shutter covering pattern X for 6 seconds, could you compensate for that by covering the inverse pattern of X for 6 seconds to get the same exposure for all pixels? So if you covered 3 satellite streaks of 6 seconds each using non-verlapping patterns (A,B,C) you could compensate for that by ending your exposure with covering the inverse of A+B+C for 6 seconds, adding only 6 seconds to your total exposure time and get uniform exposure.
Herein lies the problem. Your proposed solutions are ever more complicated as you begin to grasp the magnitude of the issue. Implementing this idea, and I'm not saying that it's good enough, would require modifications to pretty much every major telescope in the world. And there's no economy of scale because most of them are custom builds. Who's gonna pay for that?
That is only necessary in a small fraction of cases. You can just ignore the part with the streak or lower the shutter when you're using existing equipment.
If the conditions are quite stable that might work (or if one can live with limited accuracy), but conditions tend to change over time (moon position, thin clouds and of course the seeing - how much the atmosphere distorts the image) so nothing is as straightforward as one might hope for.
In space that approach would work quite well indeed, but then you wouldn't need it in the first place..
Edit: Even if one still has to mask the streak in the data in the end, it might still be useful to do, since it will protect the rest of the image from any excess blooming.
How much does the bloom extend in the image fom the streak? Can you measure it in arcminutes or is it optics dependent? Is the bloom present if you cover up the satellite exactly? (Is it caused by the sensor, or would diffraction around a shutter cause it as well?)
I think you could mitigate the problems with conditions changing if (instead of blocking out the streak in the image with some per-area shutter) you tracked the satellite in the image with a horizontal (or vertical) shutter stripe which has the right width to cover the entire satellite. This would make the data lost really minor, and changing conditions wouldn't be a problem, and the exposure would be even. Does that make sense?
If no light falls onto the detector then there is no blooming. And of course there will be diffraction from the shutter edges as well, so engineering it will be quite a challenge (one can take hints from coronographs). If the satellites does end up on the sensor then the dimension of the streak depends on the optics, how bright it is, the used detector, plate scale, etc. (if you are extremely unlucky you might have internal reflections too and they might end up who knows where on the detector - optics is hard).
what if we actually put the astronomical observation satellites above the spacex ones? that should solve the interference problems. Wasn't there a cool new telescope named after James Webb that launched recently?
And space observatories are much much more expensive than ground-based ones.
JWST for instance will cost around 10 billion dollars in the end - and they don't even have to pay for the launch cost (one of the contributions of ESA to the project is free launch on Ariane rocket).
JWST will have a 8m mirror. Currently three 30m class ground-based observatories are being built (ELT is 39m, TMT 30m and GMT 24.5m) each with an estimated cost between 1 and 1.5 billion dollars.
So you get three much much larger ground-based telescopes for the price of one large space observatory (and still have money left over).
As a counterpoint, I'll die on the opposite hill with, I suspect, the large majority of the public. And I say that as someone who has been a lifelong space enthusiast. Ubiquitous access to cheap internet has done more for humanity in the last 20 years by far than any contribution from ground-based astronomy. If the choice is between Starlink and more difficult ground-based astronomy, I'll choose Starlink.
Yeah, this is a tradeoff, and the balance seems to favor adding more satellites. We're not going to the stars for centuries at least. It's unlikely that further knowledge we're able to glean from ground-based installations will ever have practical value for anyone on any appreciable timescale. As cool as the stars are, they're really far away and damn hard to see, especially through the atmosphere.
I think long term this isn't really a tradeoff. Starlink exists to fund SpaceX ventures designed to significantly drop the costs of lifting bulk mass to space. That translates to even cheaper missions, which means space-based astronomy can become affordable.
What is a loss of some percentage of astronomical observations today, if it means putting a telescope on the backside of the Moon in 20 years, or a ridiculously large "virtual telescope" via a satellite constellation doing interferometry?
I do a lot of astrophotography as a hobby and for visual/infrared images, these satellites are a non-issue and extremely easy to deal with by simple outlier rejection techinques. One of the most basic techniques is sigma clipping, in which you stack a bunch of sky-tracked images, and for each pixel, you throw away data points that are more than a sigma or two away from the mean before actually averaging.
I already have to do this for aircraft, and aircraft do a LOT more photobombing than satellites.
The satellite trail images people post all over the internet to fear monger the public are actually processed exactly the OPPOSITE way that astrophotographers would process an image stack. They are processed by taking the max at each pixel stack to emphasizing the outliers in the stack instead of eliminating the outliers and averaging the rest. No astronomer would ever do that.
I can imagine they might be a bigger threat to radio astronomy, though.
Not just radio astronomy but any other type of research astronomy. Astrophotography has different goals. If you want a good picture, this isn't a huge deal. If you're measuring pixel-level brightnesses using state of the art equipment, the story is completely different. The "fear mongering" you state is not fear mongering, it's an illustration of just how much of a research image is ruined by these tracks.
The future of the night sky was always one filled with satellites and space ships and drive plumes.
It's silly to die on a hill that's inevitable, it's much wiser to stand on the hill and reach higher. The future of space exploration is in space, not on the ground, and the proliferation of these satellites is a sign that space exploration is getting cheaper.
Just like people were shocked that there was only one or two computers in the world at one point, they will be shocked that we only had Hubble for so long.
Indeed! We're within reach of telescopes on the backside of the moon, or ultra-long baseline radio telescopes in high Earth Orbit. This is the dawn of a new era of space research. The transition may be unpleasant, but the future is exciting!
>> The article covers the mitigations already in place and how they only partially resolve the issue.
> So in April, SpaceX instead began launching Starlinks with a sunshade to block sunlight that would otherwise reflect off its antennas, which are the main source of the Starlinks’ brightness once they have reached their final positions.
> So far, only one of these ‘VisorSat’ Starlinks has finished the journey to its final orbit of 550 kilometres above Earth. Amateur astronomers have reported that the sunshade appears to make the Starlink fainter than it would otherwise be.
> But astronomers are still awaiting further confirmation that the modifications have a significant effect, says Meredith Rawls, an astronomer at the University of Washington in Seattle. Regardless, SpaceX is now launching all of its Starlinks with the sun-shielding visor.
It seems that the impact of the sunshade mitigation is not yet fully measured?
The first few are bright, but as you said only at dawn or dusk. The vast majority of future ones are intended to be dark, with partial mitigations (not perfect, nobody is making that claim) like dark coating applied by SpaceX at their own expense.
With plentiful availability of orbital delivery, we can also expect more earth-orbiting space telescopes in our future, including private ones and with numbers possibly several orders of magnitude higher than what we have today. These will have higher orbits so that will help, and they will be largely immune to atmospheric effects.
I would suggest the astronomy community ask SpaceX and others to commit to giving key projects free or low cost launch services or ride sharing to orbit, to help compensate for some of the costs you allude to. If asked directly, Elon is often responsive.
Isn't the solution more satellites for astronomy? In fact, couldn't the constellation of commercial satellites be used to make a massive distributed hubble telescope?
Will those american billionaires pay say for more European satellites to compensate? What if this were Chinese satellites would you have the same opinion?
It would be great if this billionaires would also launch scientific satellites payed from their pocket to compensate, then I would change my mind.
Exactly, if China launched thousands of satellites ruining everyone's astronomy efforts I'm sure there would be an uproar. But US doing it? Fine, business as usual.
The US isn't doing it. Companies are doing it. As stated in the article the company which is currently planning to place satellites at a height likely to have the greatest impact is OneWeb which is a UK company. It is soon to be controlled by the UK government and an Indian conglomerate. The satellites it launches are built by a joint venture which includes Airbus.
Well, that isn't really a useful distinction in any sense of the word. The American companies are doing it, because they are allowed to do so by their country. Most countries which have any kind of space capability have their own space agencies which say what is or isn't ok to launch. If the American space agencies approve things like Starlink, then the pollution of the Earth's view into space isn't purely on Elon Musk.
Point of order: intercontinental missiles, rockets, and radio telecommunications are highly regulated industries. The US regulators have approved (and not stopped) Starlink on both fronts. I do not know if there’s any international / UN body that performs the same roles?
I can see it "Trump: China puts 10000 eyes on the sky, they pretend they want to give Internet to the poor but they have cameras and spy on the traffic, and some reliable sources told me they can release viruses from this satellites in a targets back yard, this needs to stop , I will build a space wall and China will pay for it...
> SpaceX is lowering satellite launch cost by 90% for anyone, Chinese or otherwise.
Are you sure SpaceX is allowed to do business with China? As I understand it NASA is forbidden by Congress from collaborating with China. Since NASA and SpaceX work together, might that limitation extent to SpaceX as well?
Spacex is subject to the same OFAC sanctions as every other US business. They are free to do business with most of China, however there are a number of exceptions usually having to do with the company participating in construction in the South China Sea.
Doesn’t mean new sanctions can’t be levied and certainty China seems a likely target for future increased sanctions.
No they cannot do business with Chinese governments, ITAR forbids this.
There is already history here where a failed Chinese rocket crashed with a classified American payload and caused the whole satellite anything is now ITAR
If NASA is forbidden from working with organizations affiliated with China, it seems to me that SpaceX working with China might imperil their collaboration with NASA. Then again maybe not, I don't know the answer.
Considering a less direct relationship with China already has some congressmen evidently perturbed, I think there is a decent chance SpaceX would refuse any contracts with China if for no other reason than to avoid provoking Congress further.
Ok so the answer you want is yes. Congress people can say whatever they want for political reasons, and because SpaceX is vastly out performing their preferred old space contractors, they are motivated to attack SpaceX for the smallest most ludicrous reasons like this.
But they also aren’t likely to pass any specific legislation or change what Elon does.
Historically this has only been true because of the immense cost of building super lightweight payloads using super expensive super light materials to fit in very limited payload mass requirements.
Falcon 9 is a heavy launch system that can lift up to 50,000 lbs of payload to orbit, similar to the Shuttle.
Falcon Heavy is a super heavy launch system that can put 140,000 lbs of payload in orbit.
Starship is designed to be significantly cheaper than both of the Falcons, and to put over 200,000 lbs of payload in orbit with a far larger fairing size (though Falcon Heavy is getting a larger fairing shortly).
These are all game changers the scientific and commercial space customers haven’t yet taken advantage of.
Your argument is incomplete, I said that transport in space is a small part of the costs. You can't just move the existing telescopes in space. You need special space telescopes, with special mechanical and electronic system with high reliability. You could say maybe Elon can send 6000 shit telescope that will work for 6 months and will be an equivalent to an average ground telescope.,
You are forgetting that the telescope has to work in space.
Big thermal swings, no easy air cooling, no AC outlet to get your power from, no convenient anchoring point for your telescope to push against to point a certain direction, no just bolting several racks full of off-the-shelve electronics to the telescope (none of them work in vacuum), no possibility to repair or upgrade anything, ...
Having to use lightweight materials is the least of your worries (and not even that expensive - and sometimes done for ground-based instruments as well).
With much cheaper launch costs, you can afford to send a couple more robust telescopes.
That's the vicious cycle of space mission costs put in reverse. The missions are expensive today, because launches are expensive, meaning you have one shot at doing your decade-long project, so you need to max out on risk mitigation - increasing your project length, labor costs, and launch mass. Significant drops in launch costs and increases in cadence translate to ability to launch much less robust mission (and launch a replacement if/when it fails), which drops the costs all across the board.
> Big thermal swings, no easy air cooling, no AC outlet to get your power from, no convenient anchoring point for your telescope to push against to point a certain direction, no just bolting several racks full of off-the-shelve electronics to the telescope
While by no means easy, that's still table stakes for space missions, and something there's decades of experience in around the world.
> none of them work in vacuum
Nobody is, nor was, sending the equivalent of a ground telescope installation upwell. You only send the looking part, with a downlink bolted on them. You do control and data processing planetside.
> no possibility to repair or upgrade anything
Cheap launches = you can replace. Even cheaper launches = you can try to repair. We'll need to develop that capability anyway, if we want a cislunar space economy.
>The missions are expensive today, because launches are expensive
I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky.
There are many existing communication and navigation satellites but not that many space telescopes so I think this proves that launching shit is not prohibitive expensive but I will read any claim that proves you right.
> I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky.
Radhard stuff is expensive, but not that expensive. Also space missions don't need all that much compute - they carry only as much as is needed to operate the hardware and maintain a radio link with Earth. You don't use more than you absolutely need to, because more compute = more power demands = more waste heat => need more thermal management => heavier satellite => need to cut down mass (or power demands) somewhere else => ballooning R&D costs => ...
Look, I'm not making this up. It's widely known in the industry. See e.g. [0] and [1] for the first two references I could find. I actually learned about this concept from some NASA report that featured a beautiful flowchart, but I can't find it now for the life of me. But the phenomenon is real, and that's why SpaceX has been a big deal in space circles for years now. More and cheaper launches translate to a qualitative difference in how we approach space systems.
> There are many existing communication and navigation satellites but not that many space telescopes so I think this proves that launching shit is not prohibitive expensive
Communication satellites pay back for themselves in rent the owners can extract from the users. Navigation satellites are first and foremost military projects with huge implications for national security of the states that own them - which gives them almost infinite budgets. Space telescopes are research platforms funded by taxpayers, most of whom don't understand the importance and don't care to. Astronomy can't afford space telescopes at current prices.
You can't launch a 40m diameter telescope and so you would need to launch more smaller ones, then you would need to physically connect them so they are perfectly sync(can't be done in software or with imperfect distance/teime measurements). You also need all the optical and mechanical stuff to survive the launch, the difference of tempreture and pressure from getting moved from the ground to space etc.
What I am saying if Elon or Jeff makes a telescope work harder or impossible they should pay for fixing the issue not the public and it should be fixed today not in 50 years.
Also a tax on opoluttion would make the management at SpaceX considering using different paints(or doing more with less) in before the satellite is designed and not after bad PR.
IMO you did not convince me that the reason we don't have tons of space telescopes is the launch price.
IMO we will probably need to have a few bases on the Moon and build telescopes there to get around the light pollution.
> What I am saying if Elon or Jeff makes a telescope work harder or impossible they should pay for fixing the issue not the public and it should be fixed today not in 50 years.
SpaceX is doing what it can to "fix it". There's not much more that can be done beyond just not launching satellites. At this point, you have to choose whether you want clean skies or humanity spacefaring; you can't have both. I'm strongly in the "humanity spacefaring" camp, especially that once some sort of permanent industrial presence is established in the cislunar space, we will be able to build large telescopes in orbit or on the Moon.
> IMO you did not convince me that the reason we don't have tons of space telescopes is the launch price.
I'm trying my best :). Consider also economies of scale: expensive launches means your payload is pretty much unique, which makes it expensive. Cheap launches means you can make more, which drives architecture & hardware standardization, which lets manufacturing scale up, reducing its costs significantly.
Still, so maybe we should be mathematical about this: how much it costs to fix this and tax every new satellite proportional with it's pollution. SpaceX tried to "fix" things only when bad PR hit them, before that some leaders there decided that this is not an issue.
The tax would also insensitivese to launch better/smaller satellites and not abuse the fact that launch is cheap so let's put as many stuff in orbit because we can (maybe US can get their shit together and use cables for internet like rest of the world) so Internet satellites would be used only by remote communities. IMO if you managed to somehow have electricity and old fashion telephone cables then what the hell is expensive to drag a new cable for internet to this places ?
> Still, so maybe we should be mathematical about this: how much it costs to fix this and tax every new satellite proportional with it's pollution.
That hinges on the quantifying and pricing of the solution. A smart accountant could probably figure out a fair calculation (something along the lines of % of wasted observation time, against operating costs of telescope facility in that time + depreciation). I'd love to see it.
> SpaceX tried to "fix" things only when bad PR hit them, before that some leaders there decided that this is not an issue.
I'll concede on this since I haven't been following the story until it hit media, and only then I've heard about SpaceX painting the satellites. I'm guessing they just didn't consider it at all, or were betting on astronomers not being that upset.
> IMO if you managed to somehow have electricity and old fashion telephone cables then what the hell is expensive to drag a new cable for internet to this places ?
That was before telcom monopolies, and also before people figured out they can hold infrastructure projects ransom, or block them out of spite, just because they own a piece of land that needs to be dug up or paved over.
> Nobody is, nor was, sending the equivalent of a ground telescope installation upwell. You only send the looking part, with a downlink bolted on them. You do control and data processing planetside.
That rack full of electronics is the looking part (temperature controllers, power supplies, CCD controllers, motor controllers, ...). The data processing happens in a server rack on the other side of the planet in either case (ground-based or space-based).
And you somehow are under the impression that telescopes and instruments are so cheap that it doesn't matter if we loose one every year and then just launch another one. If that were the case we would be building dozens of 3m+ telescopes all over the planet every year - but we are not, because we don't have the money to do that.
Telescopes are multi-decade investments by the institutes, so even with free (free!) launches exactly as much testing will be done as before, because we can still only afford one shot.
Disagree, if I make a factory in China that generates some ugly clouds so you can't see your beautiful sky anymore, then if you complain I give you a discount on my airlines so you can fly above the clouds and see the sky for the first time. It could happen if we let companies pollute for free.
There is a thing called pollution and light pollution is a thing,
So you have a home and someone makes noise so you can't sleep, you have a home and your neighbor has pig shit in his backyard and the smell enters in your yard.
Also I amargueing from a public(international) point of view. As an individual with terrible eyes sight I already can't see the stars anymore.
I often wonder how come we(as in, humanity) ever only launched a single Hubble telescope. Surely, once you built one, you should be able to build more. Or other countries should be able to take the designs and launch their own versions. Hubble was(and I imagine still is) occupied for weeks at the time taking pictures of certain areas of the sky. Why don't we have 50 Hubbles up in the orbit, doing different things simultaneously? Is it simply because there's no money to do so?
I also do remember the story how NASA got a couple decommissioned telescopes from some intelligence agency, which turned out to be an order of magnitude better than Hubble is, and the agency was getting rid of them because they were already outdated. I do remember reading that if those were put into astronomy use they would be a lot better than anything we have currently, but of course those are being used for taking pictures of military sites and tanks, rather than stars.
The two donated telescopes were the same diameter as the one Hubble had, but were designed to cover a larger field of view (since the small FoV of Hubble wouldn't have been very useful for reconnaissance). But they came without any instruments, so one would have to develop (or adapt the ones from Hubble) to be able to actually use it (and that's were most of the cost is).
And the main limitation is quite simply money.. and since a lot of the things that were only possible with HST in the past are possible from the ground now people started focusing on building space observatories for the parts of the optical spectrum that simply cannot be done from the ground (x-ray, far-infrared, gamma-ray).
Dude, the astronomers don't pay , the public pays.
So the people in all the world will have to pay more billions to american companies to workaround the mess those created. This sounds very mafia like - or Cyber Punk where you can't see the sky or the sun anymore unless you are a billionaire.
Someone had a great idea, we tax all bright objects put in orbit, then there is an intensive to make the satellites less bright and we make the people that pollute pay and not the public.
>>Someone had a great idea, we tax all bright objects put in orbit
Well, couple small problems with this idea
1) who collects the taxes? I can imagine some international agency in charge of it which then proceeds to spend the money on other international projects, but how could you guarantee compliance?
2) Countries which are only now starting to launch things into orbit would(rightfully) say - hey, how is that fair? Others have been able to launch thousands of satellites for free, but now that we finally got the capability to do so, we have to pay? Why?
For many reasons, ground-based telescopes will continue to play a major role in astronomy.
Space telescopes offer advantages for particular types of observations, but there are many types of observations for which ground-based telescopes are superior. The basic advantages that ground-based telescopes have are:
* Larger collecting area, which means more photons collected, which means you can see fainter objects.
* With adaptive optics, ground-based telescopes can actually achieve better resolution than space telescopes over small fields of view.
* Ground-based telescopes are far easier to maintain and upgrade.
* Much looser weight, size, radiation-hardening requirements mean that you can do things on the ground that would just be unthinkable in space. You can attach things like massive spectrometers to ground-based telescopes, without having to worry nearly as much about form factor and weight, or whether radiation will damage your electronics.
The advantages that space telescopes have are:
* No weather to deal with.
* You can observe UV and IR wavelengths which the Earth's atmosphere absorbs or emits in - which is extremely difficult/impossible from the ground.
* You can get high resolution over large fields of view. However, you can't reach the same resolution on small fields of view, because ground-based telescopes with a large aperture + adaptive optics will beat you there.
Basically, at any fixed budget, you will be able to build a much larger, more complex instrument on the ground. You only go to space when there's a compelling technical reason to do so (e.g., you need to observe UV light).
Great run down, thanks for sharing that. I wanted to make sure you saw this article, I wonder how it changes things when we have a "fast, cheap and out of control" approach to science with many cheap satellites. The article is about ground-based telescopes, but seems extendable to space-based telescopes.
No. That's not how optics works. The resolution is set by the diffraction limit of the optics, which is mostly limited by the diameter of the aperture. This is not something you can magic away (I am aware that interferometers exist, but those are very limited in their capabilities and don't replace big telescopes).
And even with free launches space telescopes are still extremely expensive, since the telescope and all it's instruments has to work in space without any tweaking or possibility for upgrades. Ground based telescopes are used for decades and upgraded with newer instruments over time.
Like I said interferometers exist but they are very limited in their capabilities.
For example the VLT interferometer is limited to observing objects that are brighter than 18th magnitude (and that's using multiple 8m telescopes! Using the auxiliary telescopes which are still 2m you are limited to about 10th magnitude).
Something that is easily within the reach of a single telescope less than 50cm in diameter (single 8m telescope can see objects fainter than 25th magnitude - 7 orders of magnitude difference!) - something you can buy for less than 30k$!
Interferometry gives you high resolution at the cost of sensitivity. And there way more things that require high sensitivity than high resolution.
And I haven't even mentioned spectroscopy, which is hugely important in modern astronomy. And there is no way around having a big light bucket - I wish there was.
This is a silly hill to die on. Did you complain(or would you have complained) when tax dollars were building space probes, meanwhile people are starving to death on earth?
"Won't somebody please think of the astronomers!" is a moral panic that I just can't get behind.
Astronomy is great. But world-spanning wireless internet is great too. If 5% of astronomical observations get messed up because 100% of people can now have access to the internet, then that is just a big shrug from me.
> Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three companies from one country.
Not to mention there will be far fewer non-processed photos. Most people won't care, but it just seems like nothing we see anymore is real.
In between the thing and your perception of it, there are so many layers of bending, stretching, reflection, quantization, imputation, and filtering, occurring through different physical, digital, and biological processes. Why does this one make the image not real?
Processes that are agnostic of the image and its artifacts feel different — “acceptable” — compared to ones that are specific to the image content itself.
I am now imagining a science fiction story where visitors to Earth initiate communication with us using faint arcs of light across the night sky. No one notices and the telescopes and cameras filter them all out. The visitors go home, sulking.
Is it a difficult problem to solve though in software? On its face it seems trivial, and something that should be part of an astronomer's job description. The cost of not having internet satellites seems to be many orders of magnitude higher than writing software to get around the problem.
To me it seems completely impossible. How exactly do you expect to replace the missing information? Statistically from the neighboring pixels or frames? That works if your goal is to make an image prettier, but if you want to make measurements on the data "inventing" the background is not good enough.
Take many short expo images, and integrate them. This way you will have smaller streaks.
Yes, the sats will occlude things anyway, and their brightness is a big problem, but they are fast moving, they can be mitigated by moving to may short expo images combined. Yes, it's an undue burden, SpaceX should do more, but they can't solve it completely.
The readout time for astronomy CCDs is typically between 2 and 30s (going faster produces more noise), so there is a lower limit on how short you can make exposures.
In LEO the apparent movement of satellites is around 3.6 arcmin per second, which means for an average sized detector that covers maybe 20 arcmin it takes about 6s to produce a streak that covers the full length of the detector (bit longer depending on the angle).
If you want it to cover less than 50% of the length of the detector you have to limit your exposure time to under 3s, which means your duty cycle will be between 60% (if you have a fast camera) and 10%(!).
And that's without even considering the loss of sensitivity you incur, because each image will have lower signal to noise since even with those long readout time the readout noise is still significant.
I'm not sure you're thinking about it the right way. Or maybe I'm not.
It seems you're assuming that every exposure you take will have a streak in the same spot from a satellite. It's more realistic that a large portion of exposures will have no streak at all, or that if you re-exposed a detector on the same piece of sky, any streak it would see the second time would be in a different place than the first. So if you expose twice and do some basic interpolation to remove the streaks, you would end up with an equivalent zero-satellite image from two exposures.
The piece that people are missing is the concept of SNR, or signal-to-noise ratio. These streaks are noise, which raises your noise floor and thus raises your detection threshold. Think of the way your eyes adjust to bright light - you can no longer see dim things around it even if they aren't obscured.
Ok, I understand, thanks for clarifying. My next question would be how many exposures would you need in a real-world setting to mitigate the issue? Ex. what's the actual likelihood of a satellite crossing your target piece of sky during a randomly chosen exposure, and how long will it be in the exposure, messing with your SNR?
Second of all: I highly doubt that this is "trivial", given that observatories are built in the most remote areas of the planet because light pollution was already an enormous problem before these satellites appeared, despite the extra costs that adds to any such project.
It's the other way around. It's possible to escape light pollution by moving away from electrified areas, whereas satellite streak ruins observations in every part of the world. Besides, the streaks are not really localized in the image. Its glow reportedly extends up to 15 arc seconds. That's a very large area for a carefully exposed array.
I meant light pollution affects the entire image, while a streak affects only part of it, which you can just remove.
A 30 arcsec stripe on an (apparently average) 20 arcmin detector is 2.5% of the total area, so it's not a very large area.
Overall, 20000 satellites at any given time cover 20kπ15acsec² of sky area, which is 0.0005% of total sky area, and over 1 second (assuming a satellite speed of 3.6 arcmin per second) it's 0.02424% of the sky, so roughly 1.45% of the surface area of a 1 minute exposure would have to be thrown out. This assumes that satellite streaks don't overlap, with overlap it would be less.
The problem is with the exposure. 1min exposures are common in astrophotography, but astronomers are complaining about the types that need night-long exposure - ones that try to study cosmology, stellar composition etc. Many observations (like SDSS) are also large field observations that observe many objects simultaneously. Even a single streak can ruin an entire exposure. The odds just grow considerably.
In digital photography, an exposure of N seconds can be produced from the sum of N/K shorter exposures at K seconds. This is more of a nuisance than a devastating blow.
You're going to have to show me the quote that makes you think astronomers claim to "own" the skies instead of just not having their usage limited and infringed upon.
I don't remember America claiming it was. The relevant international treaties are being followed. Also not all these companies are American. OneWeb is a UK company soon to be owned by the UK government and an Indian conglomerate. The satellites it launches are built in cooperation with Airbus, a European company.
Astronomers don't "own" the skies, the rest of humanity simply considers the benefits of astronomy to be higher than some satellite internet vanity project.
We can judge the value humanity places on astronomy by looking at how much money is allocated for it. I suspect it will come out less valuable, to humanity, than the service Starlink will provide.
Yes, I am sure astronomers believe in their hearts that whey they are doing is supremely important and valuable. But astronomers should also understand selection bias. Astronomers are inherently biased to believe highly of the value of what they are doing, or they would not be astronomers.
Elon Musk and some investors don't represent humanity. Hell I doubt even SpaceX values Starlink all that much, most employees I know say that it exists mostly as a filler payload during launches.
Whose whole point was a sustainable funding source for SpaceX R&D. In this sense, it's fair for SpaceX employees to consider it "filler payload", given that they have their sights set on Mars. And everyone else, astronomers included, will benefit from drastically cheaper access to space.
There is so much unwarranted alarmism about this. This is not the end of astronomy, nor is it even super serious. The "unavoidable impact" they're talking about is that astronomers will have to care about when and where satellites will appear, rather than not bothering and just throwing away the rare image with a satellite in it. A small percentage of their pixels will be affected by satellite trails and they will need to implement better algorithms to avoid them, remove them, or use different sensor technologies that can reject them better.
Sure, if you're an astronomer this is annoying, and will cost you some effort and money and time. But you'll still be able to do astronomy. Meanwhile, if you're not an astronomer, the satellites will not be visible to the naked eye in their final orbits. The entire surface of the Earth will gain low latency broadband internet access for the first time, and new launch systems will drastically reduce the cost of access to space, enabling more space-based astronomy.
Sure. Governments regulate space pretty closely and they have the ability to account for that. I'm sure the commercial potential of global broadband internet is high enough that some funding for astronomers wouldn't be a huge obstacle to the constellation operators.
This is a curious assumption. Why would the small number of astronomers get ownership over the resource of the night sky instead of the much larger population of people who want internet?
I'd argue that the positive externalities of the latter far outweigh the negative externalities of the former when deciding how to tax spacex.
> Why would the small number of astronomers get ownership over the resource of the night sky instead of the much larger population of people who want internet?
They would not. It belongs to the whole of the population, not any part of it. Depriving any part of the population, especially without consent, is what's unfair and requires compensation.
> I'd argue that the positive externalities of the latter far outweigh the negative externalities of the former when deciding how to tax spacex.
This sounds like a great way to introduce abitraryness into the situation. If it has a value to all these parties then it has a price and if people are going to deprive other people of that then they can pay for those people's loss, and even better, get everyone's consent instead of making assumptions about the greater good and collective good.
Living in a city, I didn't understand how big a deal this was until I got a view of the clear night sky in a less populated area recently. The satellites are already visible by eye everywhere, and there are only 655 Starlink satellites. There's approval for 12000, and SpaceX is seeking approval for 30000!
If they're all going to be this reflective, satellites will be the main thing we see in the night sky a few years from now. Forget about astronomy; 10 years from now you'd be telling your kids "when I was your age we used to be able to see constellations of stars in the sky". By eye, only about ~5000 stars are visible in the night sky.
I recently went for a run around Mt Saint Helens, which I started before sunrise. It's a very desolate area, with limited light pollution. I suddenly noticed dozens of satellites flying overhead and was startled by how vivid they were. First time I've ever seen them. My response was to become a little bit choked up. I haven't felt pride in humanity like that for a while. As we become a space faring civilization, the night sky will be influenced by us more and more. It's not worth holding progress back for the sake of a nice view.
It's not as big a deal as you think. The satellites are only visible to the naked eye for a few weeks after launch as they travel to their final orbits; after that they are too dim to see. The sky will not appear different than it does now to the naked eye; you will never see thousands of satellites. Most of the bright satellites you see now have been there for many years already; Starlink will not be visible like those.
Maybe, but with tens of thousands of satellites, each with a life expectancy of about 3-5 years then Space X will have to re-fill the constellation constantly.
Sure, you'll be able to see the most recent launch, just as you can now. But you won't see 30,000 in the sky, which is what everyone assumes. Also note that you can't see them at all in the middle of the night; only for an hour or so around sunset and sunrise.
How do you know what the final orbits are? Why would they not be visible on the final orbits? Sure, only a fraction of the satellites will be above you and illuminated by the sun, but at 30000 that's still bound to be a huge number.
The final orbits are approved in advance by the government; there's no mystery. They are not visible to the naked eye in their final orbits because they are farther away and they maintain an orientation that allows their sunshade to reflect sunlight away from Earth instead of toward it.
There's actually a good primary source for this cited in the article [0], stating:
"However, at low elevations near twilight at intermediate latitudes (45°–55°, e.g., much of Europe) hundreds of satellites may be visible at once to naked-eye observers at dark sites."
This is referring to Starlink's 12000 satellite constellation, so thousands absolutely is the order of magnitude we're talking about when (if) they go to the planned 30000 and when other companies do the same.
That's good to know. Still, with tens of thousands of satellites planned (that's just SpaceX) and the need for them to de-orbit and then redeploy, I think there is going to be quite a few of these things visible at any given time.
This is bad. This is really really bad. The EU has invested billions in telescopes and that's now going to go to waste. Instead advancing human knowledge it's just going to fill rich guy pockets even more.
Spaceflight wouldn't be there in the first place if astronomical observations didn't help generations of scientists (including Kepler, Newton and Oberth) evolve the concepts of astrodynamics. Astronomy is far from having given up all its secrets - many of which will surely be applied in everyday life some time in the future. Besides, nobody would be complaining if this was about making spaceflight cheaper. This is about commercial exploitation of space by destroying a scientific resource. As others mentioned, there are easier ways to bring internet to rural areas - if only there was social resolve. This is more about worldwide internet controlled by a few big corporations.
Powered flight wouldn't be there if not for generations of people playing with kites. That doesn't mean we should abolish airports because they take the prime spots for kiting.
All 30-50k satellites? SpaceX and Amazon are sending stuff up now. I expect these numbers to multiply quickly. And not just with US satellites. China and other nations might just send similar numbers up
I recently moved out of the city after many years and looked up at night for the first time in a while and was surprised to see so much stuff moving around. The first time I saw something I thought I was really lucky to catch the ISS but after seeing the "ISS" many more times in the following minutes I quickly realised it was SpaceX and friends' satellites.
I also recall last year looking up and seeing a string of about 20 bright lights moving quickly across the sky and wondering if it was the start of WW3. Turns out it was a SpaceX launch.
> A negative externality is any difference between the private cost of an action or decision to an economic agent and the social cost.
Like pollution, I think this is another perfect example of a negative externality. A few companies stand to benefit quite a lot by incurring costs and risks onto others. Maybe these its possible for astronomy and other endeavours to work around this but it doesn't seem fair that they should have to be the ones to pay for it. If it isn't possible to work around then I think we have a bigger problem here.
Personally, I'd like to see these orbits like realestate which are commomly owned and democratically managed by all of humanity. Then companies could, if people are willing, temporarily rent them with proceeds equally distributed. Like in pollution, I don't think market demand for wireless Internet really suffices as a vote here and we need to make it more explicit to really gather consent.
Wouldn't it be neat if the net result is that capturing the negative externality actually funded the launching of better space based telescopes?
I feel like this could be solved with a simple requirement that anyone launching anything shiny into LEO has to help fund space based telescopes. They're better anyway and we can have the best of all worlds that way...
Classic government "intervention" that stifles innovation under the guise of doing good. You didn't "solve" the problem. You basically made it harder for innovation from newer players to occur whilst still letting the "evil capitalist corporation" do what they want because you've imposed a cost that they just incorporate into their margins. It's not the best of both, it's the worst of both.
I thought Hubble, JWST etc could do basically everything a ground based one could do only better? Excluding radio telescopes which are huge but not effected by satellites anyway.
Radio astronomy is a prime candidate for putting installations on the other side of the Moon, which is something Starlink is working towards (as its whole point as a business is to fund Starship R&D).
Everything. Whatever one can do on Earth which requires big optics and maintenance is many millions times more expensive to do in the orbit. And the many million times higher expenses of all astronomical projects in the world are certainly not going to be covered by the operators of the "cheap and small" satellites.
Optics, for the purposes we talk about, just doesn't work small. One needs big telescopes, big telescopes just can't be simply launched like the "cheap and small" can -- there are no scalable technologies for that.
Imagine it like this: there is a technology to launch "ant" satellites. But on Earth, one has "elephant" observatories everywhere. No rocket can even launch a single one. And the maintenance of an elephant in the orbit is insanely complicated.
So those who dismiss the problem with "ha ha we can send ants for them too" just show that they don't even understand what the problem is. But to uninformed people, it sounds "plausible."
No, not everything we've discovered was made by Hubble, and also won't be made with JWST.
And the demonstrated complexity of JWST should just give you pause, if you read about it. It's still not launched. The direct development of it started in 1996, the current plan is to launch it "just" 25 years later(!) You know all the problems to "get it right" to unfold? Exactly because the limitations of what can be launched and how.
More specifically, at one moment in time it was believed that the atmosphere limits what can be done from Earth. But then these problems were solved: for almost all purposes, Earth based observatories remain millions of time cheaper and better ways to make observations (as in, when something gets expensive enough, it won't even be done at all).
From 2019:
"This Is Why We Can't Just Do All Of Our Astronomy From Space" by Ethan Siegel
Moreover, you can also read in other articles that even the approaches that were suggested by the astronomers to mitigate the problems were completely ignored by the satellite operators.
SpaceX has absolutely taken steps to reduce the albedo of Starlink satellites. New satellites have sunshades that drastically reduce their visibility. It's just not as simple as changing the coating, a modification that has huge thermal implications.
Isn't the mess that is JWST caused not only by cost plus contracts but also having to put the whole thing on top of an Ariane 5 ?
Putting it into a 9 meter diameter Starship, possibly in multiple pieces that would be assembled and periodically serviced by crew flights would make it all much easier, cheaper and more performant.
> possibly in multiple pieces that would be assembled and periodically serviced by crew flights would make it all much easier, cheaper and more performant.
Again, wrong belief, again like I mentioned before, in the style "ha ha we can send ants for them too" (answer: no we can't), see FAQ:
it's hard to make the claim that the private development of space doesn't inspire people in the same way as the old national projects did. my heart swells watching a livestream of a satellite being delivered into orbit. but "memelord space magnate delivers global internet access" doesn't give the endeavor the gravity it deserves.
space is the last realm of mystery. to me, a glance toward the sky and the stars has always been the fastest way to feel the presence of God. it won't lose that for me, even if the daytime sky fills up with blinkenlights. but it might not provide that for anyone else, anymore, if it stays—forgive me—on this trajectory.
> The planets are all long gone. The inkblot finally closes overhead and the last star winks out. The gibbous Moon remains shining balefully down on the world for a tense and hopeful minute, but then, in an eyeblink, is swallowed up by one final event horizon, and spirited away.
> Left in utter darkness, the former astronomer tries and fails to deal rationally with his loss, and his isolation from the human race who, as the voice rightly tried to tell him, has really lost nothing.
What I'm concerned about is how much the launching of tens of thousands (maybe hundreds of thousands) of satellites will affect our ability to launch things out of orbit. Launch windows are already very precisely calculated, and the more junk we put in orbit the harder that will become.
There is no issue with controlled and tracked satellites; we could have orders of magnitude more. The real issue is space junk, derelict satellites and collision debris. In high orbits space junk is essentially permanent pollution, which is very worrying. However, in low orbits space junk is guaranteed to fall out of the sky within a few years due to atmospheric drag. So there is no real space junk issue in low orbits, and SpaceX has modified their constellation plan to use lower orbits for this exact reason.
I'm not saying it isn't a problem, but aside for Covid there are usually 10,000 flights in the air at any given time on average, with several hundred thousand flights in 24hrs. A lot of those are concentrated during the day over the continental US, which is the most congested region in the world. So on that basis, an evenly distributed web of LEO satellites should be manageable, especially as they will also be much more vertically distributed than planes.
that's actually a fascinating idea. think about how humanity solves the environment problems and fusion works out, bringing global peace and prosperity for once. Now a smallish rock comes from space. We don't see it, because of "we go to mars, bro"-elon making ground based astronomoy infeasible and debris from crashes from his great internet satellites making 9/10 new launches fail. so, even if we saw it, we couldn't launch a nuke to deflect it. BOOM. There was the USA and Elons android son is just reduced to dust by his daddies hybris.
Space based observation of objects on potential collision course with Earth is far superior to earth observatio. For example you can't really observe anything coming from the direction of the sun. Look up NEOCam project that aims to have a near Earth asteroid telescope in solar orbit.
Fiber never solves the problem of internet on a ship, or plane, or tank. It never economically solves the problem of internet in the middle of nowhere.
If the FCC had teeth the US would have internet going up to the "edge" of nowhere (for some definitions of the boundary), but there are always limits. Satellites nicely complement that by working best in non-dense areas.
Lots of people don't think Starlink is important enough to be barely visible over the whole earth. Lots of people think it is. I don't care one way or the other, but I'm glad that the precedent is being set. Someday humanity will have a reason to put something big into orbit, and at that time those who favor progress won't want to have to fight the NotInMySky fanatics. As we can see ITT, they're worse than the New England wind farm opponents.
In unrelated news the cost of launching a space telescope (that doesn't suffer from atmospheric perturbations or cloud cover) has decreased by several orders of magnitude.
Launch costs are only a fraction of the cost. The cost of a space telescope itself is massive, regardless of launch cost. The James Webb telescope is massively over budget but even it’s original $1 billion cost and 10 year build time is much more than many ground based observatories would have costed at the time. Currently it’s cost is about x10 it’s original estimate and 14 years late, partially because it’ll be on its own once it’s launched.
On the ground, $1 billion or less buys you an extraordinarily large telescope such as a 40 metre mirror or a distributed array. These are needed to study very distant objects in detail and impossible to build in space.
True, but if James Webb launched in a fairing as big as Starship, the unfolding mechanism that’s driven most of it’s delays and cost overruns would have been far simpler.
And space telescopes don’t suffer from atmospheric distortion, can focus on the same spots for days straight to collect more light, etc. those are huge advantages.
The satellite itself is way more expensive then a ground based telescope. Maintenance of a space telescope is much more expensive then a ground based telescope. All in all launching a satellite is just a fraction of the total costs of a space telescope.
> Your link describes a failure of SpaceX's internal ticketing system which resulted in ESA thinking that SpaceX were ignoring them.
I'm not saying they are anti-space telescope. I'm saying I'm seeing little evidence they want to play nice with other people who have a stake in space. I have seen mostly evidence to the contrary.
Regarding that particular incident; ESA's (way larger) satellite had that orbit / trajectory for quite a while before SpaceX decided to enter it's path. SpaceX should never have created that situation to begin with. And when the situation was created (for whatever reason) SpaceX should have manoeuvred their satellite out of the way without requiring ESA intervention to begin with. And then when ESA had to ask they should have responded. That can't all be blamed on a faulty ticket system...
Satellites naturally cross paths over time, there is no “ESA” path. This is standards and expected, SpaceX is only guilty of a support failure, which has been corrected.
And SpaceX has designed and is implementing shade visors on all new Starlink satellites at their own expense, for the sole reason of reducing their reflection and brightness for astronomers.
No one made Elon do that, he chose to significantly increase the cost and complexity of his satellites to help astronomers.
As you say, there are standards and expectations that SpaceX failed to uphold. They shouldn’t be praised or thanked for doing what they should have done in the first place and only corrected after been called out.
The ESA thing, and the standards based thing, is a communication failure, where SpaceX failed to promptly reply to an email by accident.
The reflectivity based thing is something without standards more stringent than what SpaceX was already complying with, which they voluntarily chose to improve to be a good citizen, and in which they are going above and beyond the existing standards.
Not entirely unrelated. The economies of scale created by the demand for launching these "megaconstellations" is going to be a big driver for said cost reductions.
The answer shouldn't be that astronomy has to have smaller, less efficient and slower built space telescopes that cost up to 100 times as much as ground telescopes.
Size matters for telescopes and there's a limit to what can be launched. Whilst Hubble provided amazing insights it can't replace all ground telescopes. Additionally ground based telescopes can be fixed and upgraded without the need for an astronaut to be flow to repair it, a capability that doesn't currently exist.
Seems like the perfect use case for Vantablack. Of course the satellites will still block ER as they pass across the sky, but at least if they aren't reflecting so much light it would surely be of some help?
> But the black paint made the satellite thermally ‘hot’, harming its internet operations, said Patricia Cooper, SpaceX’s vice-president of satellite government affairs, at a recent webinar.
In conversational English what I said is != blocks ALL light without absorbing ANY heat.
Visors block enough light to greatly reduce reflected light, and do it without substantially increasing satellite temperature. There is a thing called an insulator, which I hear can efficiently reduce the transfer of heat from things like visor to satellite.
It is possible to reflect the light away from earth and the satellite, which is all the astronomers want and is blocking the light from reaching the main body of the satellite.
It is also possible to absorb the heat somewhere else if you do just absorb the light.
I mean... for any sort of shade to work they must be doing some sort of station keeping to keep it between the satellite and the sun. Moreover they need stationkeeping on their final orbit to point their antenna in the right direction. So I'm not sure I see your point?
The OIR report, if you bother to actually read it, also details that a) astronomers agree that providing world-wide broadband is a worthy cause, and b) that there is close cooperation between astronomers and at least SpaceX to work out mitigations.
ok, so 30k satellites from SpaceX, 60k from OneWeb. I anticipate this is just the beginning, other US companies and other countries will want to launch similar amounts.
What will the impact be when there are 500k+ satellites in LEO, who decides who can launch more?
Considering the commercial pressure, regulatory agencies are likely to just reduce the collision avoidance margins. (I remember reading that this is already happening, just don't have a reference). It's easier to keep government agencies in line compared to conglomerates. But it would be fun when the Kessler syndrome starts. You could imagine that the probability increases when there are more satellites in one layer - especially LEO. I wonder how much all the recent launches affected that probability.
You shouldn't judge other countries by western standards. There are a lot of places with poor or non-existent internet. But I fear that the reason other countries will do the same is because of their current infrastructure. Capable countries would be weary of ceding the control of their internet to American companies. We already have a splintered internet with countries and companies addicted to monitoring and controlling information (which would have been impossible in the first place if it was designed following the original principles of creating a mesh, rather than a hierarchy). Why would anyone give up now?
I'm not expressing a pro or con opinion here, but I'm curious. Did this same conversation happen when we started light polluting the city? Was this why observatories adapted by moving to darker locations?
On the surface this seems a wee bit absurd, but I wonder if a case could be made that it's time for more space-based telescopes.
That is exactly what happened. It's clear even to the naked eye - people still freak out when power grids get knocked out at night. They see far more stars and think that's what caused the failure. To be more technical, the EM radiation signals that astronomers are interested in is very faint and barely above the background noise level. This is why they have to use large aperture and long exposure to essentially amplify the difference between signal and noise. They can resolve fainter signals (images) if the noise floor (light pollution) is less.
Compared to space telescopes, ground telescopes were limited by atmospheric interference. This has improved much lately with adaptive optics. Space telescopes are better, but it's too costly. You will never see a mega telescope constellation, because there is no money to be made. Ground telescopes still generate considerable valuable data (in scientific terms. corporates wouldn't care any less). Even individuals have ground telescopes that do this. Some projects like Sloan Digital Sky Survey (https://www.sdss.org/) puts massive amounts of data in the public domain. SDSS also does observations that are impossible with space telescopes.
Space telescopes are good, but are complementary to ground telescopes - not a replacement. When (some) people say that we should simply forget ground telescopes in favor of space telescopes, they are actually asking to throw away cheap, accessible, democratic, inclusive and sometimes unique way of astronomical observations in favour of an incredibly costly, elitist and closed methods which is viable only to big corps who have little interest in it because of lack of short term profits.
An aside, there are some people in this thread asking astronomers to stop complaining and just remove the streaks from the image. I would say that's incredibly philistine stance - science has long term benefits that is underrated compared to commercially motivated projects with perceived short-term social benefits. An approach suggested is to statistically remove the streaks from image. That's against the whole purpose of these observations - astronomers are interested in the details that cannot yet be statistically predicted. Another approach is to use multiple exposures and combine them. Again - the signals they are interested in often takes night long exposure before signal is sufficiently amplified above and noise. This can't be solved with multiple exposure. The third approach is to close the sensor (usually CCD) with a shutter when a satellite is in the vicinity. This is more viable. However, this is going to be hard and is going to waste a lot of exposure time.
Did you actually read the article? The impacts on research astronomy range from insignificant to significant depending on the application, and some things are harder to mitigate for than others. "Removing the streaks from the image" is exactly one method of mitigation.
> “There’s no place to hide in the middle of the night from such a satellite constellation,” says Tony Tyson, a physicist at the University of California, Davis.
Fortunately this has never been true for Starlink, which are at such low orbits they are always in the earths shadow at night, excepting dusk and dawn.
Has anyone talked about the possibility of putting our astronomy tools in orbit? Seems like as it becomes feasible to put megaconstellations in orbit, it also becomes feasible to put more telescopes in orbit. Wouldn't that solve the problem?
I'm pretty pissed billionaires and their stupid toy internet projects have ruined my chances of taking a clear picture of the asteroid in my name (won at an Intel ISEF science & engineering olympiad in high school) for the foreseeable future :( .
It only transits the earth into a position where the sun lights it up every three years - I'm still working on finding a university to aim a spectrometer / laser at it so I can identify it's mineral composition and decide how much to charge asteroid miners for it ;)
Since their internet service will generate a lot of money, maybe spacex should just provide very low cost launches of future telescopes. Or maybe spacex should launch their own telescopes in partnership with researchers and sell the service for a low fee.
I also hope we tax companies that launch and own satellites to fund a clean up service that de-orbits all the junk before they cause the Kessler syndrome.
Part of getting a FCC license for space radios is having a plan to avoid Kessler syndrome. For things like Starlink that plan is "stick them in low orbits so they naturally deorbit within a few years in the absolute worst case".
> Since their internet service will generate a lot of money, maybe spacex should just provide very low cost launches of future telescopes.
That's exactly what they're doing. Starlink exists to fund Starship R&D, which will translate to much cheaper launch costs for everyone, not just astronomers.
Could a country (or a continent) in theory remove satellites hanging above their area? What if countries decide to extend the airspace to the aerospace?
These are low-orbit satellites and they will eventually "fly over" every point on the Earth up to their maximum inclination. Only geo-stationary satellites are "hanging above an area" and suffer from high latency because of the speed of light.
Legally speaking "airspace" does not extend beyond the atmosphere. There are treaties for this, otherwise almost all satellites would need approvals from almost all governments.
How does this work at sea? I don't know much about how aggressive (or not) "freedom of navigation" operations really are. They don't appear to be too friendly in the Strait of Hormuz or the South China Sea.
However it is supposed to work and however it does work at sea, is the situation similar for space?
> What if countries decide to extend the airspace to the aerospace?
I imagine the US would consider it an attack and retaliate (maybe economically, militarily, or covertly) against the "attacking" country.
> What if countries decide to extend the airspace to the aerospace
This is basically unthinkable.
Attempting to knock down all the satellites that ever fly above your country would mean knocking down every non-geostationary satellite that ever reaches your latitude (or any latitude farther from the equator than you).
Satellites are a key part of how we all know if anyone else is launching nuclear bombs or doing anything else so stupid. In the event that a country tried this I would expect that the foreign reaction would be very extreme. In the event that a country succeeded I would put the odds of nuclear war at above 50% and of conventional war at near 100%.
On the flipside you might almost get away with knocking down a few satellites with relatively minor reactions (at least compared to war, and if you had some good justification), as long as you don't try and knock them all out...
There is a very important distinction between airspace and plain space. Violation of a country's airspace is a wilful act (unless of course you're lost). But you will inevitably have to fly over another country if you want to be in orbit. Even geosynchronous slots are limited to the equator (GSO insertion also requires phasing). This doesn't prevent countries from claiming 'aerospace' and destroying invading crafts. However, other countries could do the same and space exploration will be a non-starter for humanity as a whole. This is probably the reason why countries agreed to space treaties allowing overflight - and it will probably remain the same.
Of course, this logic doesn't apply to suborbital flights. Any country with the means will probably just shoot down unauthorized objects on suborbital trajectory into their airspace.
So the next logical step is to move astronomy into space. I mean all the astronomy, including an amateur astronomy. Elon Musk should launch 100k telescopes into orbit (somewhat higher than constellations of satellites), so I could pay $100/year to rent one, to write a program controlling telescope taking pictures and sending them to me.
Just star watching in general's become somewhat disappointing. I remember satellites were nearly as rare as meteors to see and almost as exciting when you spotted one. Now though, it's hard to even look at the stars without something moving in sky. Every couple minutes there's satellites.
I can periodically see with the naked eye what appear to be "moving stars" (about the same approximate brightness as an average star), and appearing to orbit the earth (moving in a "straight" line across the sky).
What you describe does sound like a satellite - but it could also be a rocket body. If it moves slowly enough and lasts long enough to for you to show it to another person, it probably is a satellite or rocket body. As mentioned, it also travels straight and shows up close to dawn and dusk. You can get predictions for sighting in your area from Heavens Above (https://www.heavens-above.com/).
It gets more interesting though. Most satellites have brightness that changes slowly as moves - due to change in illumination. But occasionally, you would find ones which dim and brighten in cycles. This indicates that the object has no attitude control and is tumbling in space. That could be a dead satellite or a rocket body. Rocket bodies are spent rocket stages which loiter in space for a while after completing its mission. Then there are flares. Some satellites (like the old Iridium constellation) occasionally reflect sunlight right at you (unlike diffuse reflections in normal sats). This is a very local event. Some flares can get brighter than any planet or stars.
It's also possible to identify what you are seeing. That used to be my hobby. You would record the time it appears, how high it gets, the direction in which it flies, how bright it gets and when it disappears. With experience, you can get a good enough estimate of the brightness (magnitude) and angles even without instruments. You would then compare it against satellite predictions like Heavens Above to identify the exact object. The one I was thrilled about was a Russian satellite powered by a nuclear reactor (a fission reactor, not a decay battery like RTG). Some of them are still in LEO (https://en.wikipedia.org/wiki/List_of_nuclear_power_systems_...).
Well, I don't expect starts to move (relative to each other), and angular velocity is harder to compare with a moving plane that may not be passing directly overhead and so appears slower, but yes, faster than a plane.
I appreciate the arguments on both sides of this, but it's hard for me to get past the point that the satellites are temporary infrastructure, whereas Earth-based fixed wireless or fiber/wire lines are fairly permanent. It's hard for me to understand why the solution here is the temporary one.
A decade ago I think my opinion would have been different, because technology didn't make offering gigabit bandwidth via wire/fiber and fixed wireless pretty straightforward. So, back then you could have argued everything was temporary. Nowadays, I suspect gigabit fiber/fixed wireless will last a very, very long time before being outmoded (if it ever is).
So, I'm asking myself whether it isn't just more sensible to put up the fixed investment to connect remote areas using existing technologies rather than blasting off satellites again and again to do it.
If you think you can competitively install fiber to all the areas that will be served by Starlink, then it seems you should be able to outcompete them. No one's preventing you from giving it a try.
Well I mentioned Fixed Wireless as well. Also, there's room for government in this. That's like suggesting highways, high-speed rail and airports should all be privately funded. In most cases, societies have chosen to make those projects the purview of the government.
I agree, but that doesn't affect the question of competitiveness between satellite and ground options.
A few thousand satellites sounds like a lot, but the amount of ground installations that would have to be done to give the same area of access is staggering.
I don’t think it’s a conspiracy to imply that several nations likely have a significant body of research on stealth satellite technology that could likely solve the problem at hand.
Hopefully they can come up with some sort of 'vanta black' coating for the sats that reduces this issue. I agree with there needing to be a tax on bright, private sats in orbit. Space is getting more democratized, but not nearly so much so that an international body wouldn't be able to slap fines on companies putting 'disco balls' in orbit.
Another thing is that our skies will probably get brighter overall when we resort to stratospheric sulfide injection to try to reduce the effects of global warming. Anyone that doubts this will happen needs to come to grips with the fact that this is our cheapest most readily available means of reducing temps until we can get our emissions under control. We're going to need to fund a lot more space based telescopes to preserve our ability to do science.
Perhaps putting a camera at the outer side of each satelite and a screen at the facing-to-earth side transmitting what the camera sees could help. Plus google advertising benefits, of course.
Maybe it is time to think about moving astronomy to space or possibly the moon. Issues for years about street light polution. Even ducks show up sometimes on astronomy photos.
If you take long exposure of dim object, bright satellite passing in front of it will saturate signal and there will be nothing to recover. To avoid that you need to track all the satellites and split one long exposure into multiple shorter ones - but that multiplies read noise accordingly.
This is why I take 500+ images and process them. I don't think the moving satellites would cause any harm to long exposure deep space photography. I agree if you take 30 pictures, it could be a problem.
> This is why I take 500+ images and process them.
If you do 500 exposures you get 500x read noise of the sensor mixed with signal. Modern CCD and CMOS sensor have low read noise (compared to thermal and shot noise) but not zero.
For scientific observations of faint objects long exposure times on order of hours are necessary, for amateur astrophotography you can just go with multiple exposures.
A deep image will typically consist of many 20-minute exposures. You can't have the exposure be too short because the CCD read-out process introduces noise, so you want as few read-outs as possible. But if the image is exposed for too long parts of it may saturate and start to ruin the rest of the image. (Plus you may have the whole thing ruined by a cosmic ray or a satellite or something.) Something around twenty minutes is generally the sweet spot.
Throwing out an image or two that had a satellite or cosmic ray pass through out of a few dozen isn't so bad. But if every single one of the images has a satellite trail you may be out of luck.
That’s intentional and I think it’s because most articles on the form “how x something something y” don’t actually explain how at all. Even when they do explain how, the title is often just as good without the word how.
Instead of using the "How" title, it'll be better to use the answer as the title.
So instead of "How satellite ‘megaconstellations’ will photobomb astronomy images" it would be better with "Starlink satellites might interfere with space observations from Earth" or similar
I believe it would be difficult to further prevent this from happening since there is so much more demand for global, low-latency wireless internet than for astronomical observations.
> there is so much more demand for global, low-latency wireless internet than for astronomical observations.
This is very much not true and a remarkably narrow utilitarian view.
I understand US folks are poorly served in terms of ISP infrastructure and competition but please don't try to project those issues as a 'global' problem.
Internet service is a solved problem, you have transoceanic cables and distribution networks which garantee reliable, high bandwith, _wired_ internet service.
Wireless service is a solved problem in densely populated areas, again the issue in the US is the ludicrious pricing of mobile data plans.
The only use-cases that this serves are high-income people that want to go off-grid but are unwilling to sacrifice high-bandwith, and military deployments (Which SpaceX does not hide as an objective). To me these are very poor gains for all the negative impact it brings to science and the 'global' public.
The demand is not limited to americans, most third-world countries will benefit from having high speed internet unconstrained by local infrastructure and lack of investment. Having stayed in South East Asia I know the locals would very much appreciate having more than one option: pay-as-you-go mobile data bundles.
Even in rural parts of Scandinavia where I spent my vacation, 4G signal was too weak and ISP's refuse to lay fiber unless the whole neighborhood commits to subscribe.
This may concern millions of people who need basic or better internet access, meanwhile there are only a few thousand astronomers in the world.
The demand that exists is tackled by an increase and expansion of the existing ISP and public infrastructure.
A satellite based internet provider is inneficiently duplicating the existing fiber/copper/cellular infrastructure but more importantly cannot scale to serve the billions of people you mention in your comment.
Do the maths you cannot keep up this alleged 50Mbps link if you add more than a few million users, there is a finite amount of satellites they can add in contiguous trajectories.
The capacity issue means this will never be affordable but to a few select few or state/defense actors.
I agree with your problem statement but this unfortunately is just not the solution.
"SpaceX, an aerospace company in Hawthorne, California, has already launched more than 650 of a planned 12,000 Starlink satellites. Other operators include the London-based OneWeb, which has launched 74 of what it hopes will be a gigantic fleet of 48,000 satellites, and Amazon, which last month received US government approval to launch 3,236 satellites for its planned Kuiper service."
We need to do something about millionaires. Urgently.
But also global governance: space is not US's backyard.
Millionaires are individuals; spacex and oneweb are companies.
Rich people aren't the problem themselves, a lack of regulation and taxation is. In this case, the FTC (iirc) can just approve spacex launching tens of thousands of satellites. This is weird because space is either international - so should be regulated internationally - or sovereign, the bits passing over other countries.
But the world is busy with other shit than space legislation right now so eh.
> We need to do something about millionaires. Urgently.
Can you elaborate what premise this conclusion follows from? And what do you want to do about them?
And going out on a limb, I would assume you have a problem with the satellites, but Amazon, SpaceX and OneWeb are companies, not a Millionaires. So maybe you meant to say we should do something about companies?
> I would assume you have a problem with the satellites, but Amazon, SpaceX and OneWeb are companies, not a Millionaires.
Elon Musk is CEO of SpaceX and owns > 50% of the shares. As for Blue Origin (aka Bezos / Amazon); Bezos is the owner of the company. That means these people can make decisions on their own without consulting anyone else. They appoint the board, they appoint the CEO, etc.
And sure, there are outside investors. However these investors can only marginally influence anything because they can not get a majority of share holder votes (since Bezos, Musk have > 50% shares). Maybe they got a seat on the board if their investment is large enough. But then what? They still can't get a majority in the board. Besides the only reason these investors want to participate is because the whole thing is controlled (and partially bankrolled) by Musk and Bezos.
So are you positing that it would be impossible for a company to make such decisions if no individual shareholder owned >50% of the shares? If so the problem is still not with millionaires.
And I'm not sure by what mechanism this will function. What will prevent a company where no individual shareholder owns >50% of shares from making a similar choice?
So you say this idea was born by the company and not some human ambition? How did Amazon the company, or SpaceX the company come up with this? Nothing to do with Bezos and Musk for sure?
> So you say this idea was born by the company and not some human ambition?
Not a thing I said.
> How did Amazon the company, or SpaceX the company come up with this?
Companies have employees, employees are humans with brains, they come up with ideas.
> Nothing to do with Bezos and Musk for sure?
I'm sure the normal company structures were involved in approving strategy. I doubt the idea originated with either Bezos or Musk, and not sure why their net worth has much to do with it.
If you have a problem with ambition, ambition is something many people who are not millionaires have.
I don't think it has anything to do with millionaires. Satellite internet has demand. It will happen no matter what.
What we need is a global regulation for satellite brightness. It was never truly a problem until now, and sadly, these type of legislation tend to happen after the problem already arose instead of anticipating it.
The sky will probably be screwed for a while until we have a global standard.
Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three companies from one country.
This is cost turned into an "externality" and foisted upon astronomers--at every scale of investment--all over the world. Stock holders in these companies won't pay for it, but tax payers everywhere will pay for the mitigations. Not cool. This is a hill I'll die on.