SpaceX first attempted to address the brightness problem with an experimental “DarkSat” included in a batch of Starlink satellites launched in January. The satellite used what the company described as experimental darkening treatments over reflective surfaces, like its antennas, in an effort to reduce the amount of sunlight it reflects and thus make it darker.
While DarkSat has shown some promise, appearing about one magnitude darker than untreated Starlink satellites, the company is moving in a different direction. “We found an option that is even better than that, which is basically to give the satellites shades,” he said.
Musk and others at SpaceX have previously discussed a sunshade that they compared to a patio umbrella that would deploy from a satellite, keeping the antennas in shadow. Musk, at the committee meeting, described a concept called VisorSat that would deploy panels, like sun visors mounted on a car windshield, to block the sun.
“We have a radio-transparent foam that will deploy nearly upon the satellite being released, and it blocks the sun from reaching the antennas,” he said. “They’re sun visors, essentially: they flip out and block the sun and prevent reflections.” He predicted that the visors would have a “massive effect” on the brightness of the satellites.
[...]
SpaceX has already made progress darkening the satellites, with newer satellites about one magnitude darker than the original “v0.9” satellites launched in May 2019 even without the darkening treatments used on DarkSat. If the satellites can be made about a factor of two darker than DarkSat, Tyson said a technique to correct for the nonlinear crosstalk can work, although it is computer intensive and won’t correct for the original streak left in the images by passing satellites.
Exactly, and that's why SpaceX fanboys will just never understand or side with people who disagree with this idea: because in their mind, SpaceX and Elon Musk are the exemplar of lawful good, and...
Exactly, and that's why SpaceX fanboys will just never understand or side with people who disagree with this idea: because in their mind, SpaceX and Elon Musk are the exemplar of lawful good, and justify the outcome pragmatically by saying "millions of people will be able to get internet". It's not about the outcome, or whether the company is intrinsically good, it's about the lack of consultation and discussion that's taken place, and the commercialisation of the night sky which is no doubt something owned by all of humanity.
There are already a number of less dense satellite constellations providing telecommunications services. As far as I can tell, a lot of people seem to take issue with SpaceX simply because it is...
There are already a number of less dense satellite constellations providing telecommunications services. As far as I can tell, a lot of people seem to take issue with SpaceX simply because it is more well known, and because of Elon Musk’s involvement. Did the same people who are coming out against Starlink come out to protest the other telecommunications satellite constellations that have been launched? What about the launching of the ISS? What about sky writing, airplane banner towing, or airplanes in general? I think it’s hard to take people seriously when they attack Musk and his ventures personally, and don’t apply the same criticism to more obscure entities.
I do feel bad if your amateur astronomy projects are affected by artificial satellites, but at this point, I feel like that is a luxury that individuals can forego for the benefit of all the people who will gain access to higher bandwidth internet connections. Why does your astronomy hobby outweigh rural demand for communication? Are there critics who actually have put forth a rational critique of the standards bodies who regulated and approved Starlink (and other constellations)?
No, people take issue because Starlink type constellations are fundamentally different than on of the examples you listed here. This is a huge problem for actual scientific collaborations, many of...
There are already a number of less dense satellite constellations providing telecommunications services. As far as I can tell, a lot of people seem to take issue with SpaceX simply because it is more well known, and because of Elon Musk’s involvement. Did the same people who are coming out against Starlink come out to protest the other telecommunications satellite constellations that have been launched? What about the launching of the ISS? What about sky writing, airplane banner towing, or airplanes in general? I think it’s hard to take people seriously when they attack Musk and his ventures personally, and don’t apply the same criticism to more obscure entities
No, people take issue because Starlink type constellations are fundamentally different than on of the examples you listed here.
I do feel bad if your amateur astronomy projects are affected by artificial satellites, but at this point, I feel like that is a luxury that individuals can forego for the benefit of all the people who will gain access to higher bandwidth internet connections. Why does your astronomy hobby outweigh rural demand for communication? Are there critics who actually have put forth a rational critique of the standards bodies who regulated and approved Starlink (and other constellations)?
This is a huge problem for actual scientific collaborations, many of which are publicly funded endeavors being handicapped for a private venture. I am a cosmology PhD student, and I can unequivocally say that Starlink type constellations present a tremendous problem for ground based observations, and it is not as easy as just "sampling around them". These satellites are so bright that they often completely ruin exposures that are trying to image extremely faint objects Megaparsecs away. I have been attending a decent number of talks on possible methods to work around this, but the general consensus in the field is that as these things become more common the problem will be intractable.
I know it can seem like an overreaction because the satellites are small and the sky is big, but please, please believe professional astronomers when they say this is a whole different type of problem than what we've seen before. Professional observations need large patches of the sky for long times with high sensitivity.
I personally don't think a single company should be able to take advantage of a broken regulatory process and completely pollute the night sky, seriously hampering the work of large, publicly funded scientific collaborations. It boils down to sacrificing the commons for private interest.
EDIT:
None of this to mention the impact on other wavelengths, nor Musk's absolutely inadequate response that "the future of astronomy is space based telescopes, anyway".
It's not quite as simple as that though: SpaceX is unique because they're the first company to have the capacity and capability to launch tens of thousands of satellites. They own the railroad and...
It's not quite as simple as that though: SpaceX is unique because they're the first company to have the capacity and capability to launch tens of thousands of satellites. They own the railroad and the town at the other end, and they're taking advantage of an antiquated approval process that was neither designed or intended to approve mega-constellations. That's why this is problematic. Their success has made them a titan of the industry, and that's often where problems lie. Companies get successful, they get big, then they get too powerful. We've seen it time and time again—take a look at the tech industry right now, as a good example.
Prior to this the largest satellite constellations were the Iridium constellation, which actually nearly failed as a business before, and had a sum total of < 80 satellites in orbit. SpaceX already has over 400, and potentially is estimating up to 30,000. That's a magnitude of scale difference.
I've followed SpaceX (and many other spaceflight companies!) for a number of years, when they were launching puny rockets that had parachute recovery systems in them, from Kwaj in the Marshall Islands—and believe it or not I'm actually rather enamoured with what they do, and generally supportive of their actions (minus launching cars into space, and Musk himself, who is an all-around douchebag)—so yes, there are very valid reasons apart from Musk-is-popular-and-fun-to-mock to question Starlink.
I do feel bad if your amateur astronomy projects are affected by artificial satellites
This is a heavy dismissal of a serious issue. It's not just amateur astronomy that's important, it's professional astronomy—and darkening the satellites doesn't solve the problem, they're still there and will still appear in many large sky surveys, especially ones that don't monitor visible light. I think you'll find many astronomers and professional scientists who are frustrated about the lack of consultation they've been invited to, SpaceX appears to only be doing it after the fact. See Marco Langbroek on Twitter, for example.
Presumably professional astronomers who have access to the resources to do continuous observation of the sky can sample around the satellites? There is a lot of sky up there, and even tens of...
It's not just amateur astronomy that's important, it's professional astronomy—and darkening the satellites doesn't solve the problem, they're still there and will still appear in many large sky surveys, especially ones that don't monitor visible light.
Presumably professional astronomers who have access to the resources to do continuous observation of the sky can sample around the satellites? There is a lot of sky up there, and even tens of thousands of satellites do not obstruct very much of it at any given point in time. For those who are doing long exposures pointing at the same point for extended periods, that is a larger problem, but presumably already has the issue of objects like the ISS transiting across whatever object further out there that you are focusing on.
You can make bold claims about the night sky being a “birthright” or whatever you want, but there are many countries now that are considering high speed internet access a human right as well. How can we resolve such conflicts of interest on a global scale when our species is still regulating activities that have global impact via non-global governance?
No, in fact, commonly it's the opposite way around! Their needs are often so precise and strict that deviations from the intended conditions result in completely garbage data, as per the comment...
Exemplary
Presumably professional astronomers who have access to the resources to do continuous observation of the sky can sample around the satellites?
No, in fact, commonly it's the opposite way around! Their needs are often so precise and strict that deviations from the intended conditions result in completely garbage data, as per the comment from an (amateur, apparently who's points don't count?) astronomer I linked in my reply to @Wes:
"From my point of view it is frustrating when you have to delete 25 per cent of your pictures during an imaging session. I'm a bit afraid of our future view of the night sky when there are 10,000 of them in orbit."
Professional astronomers will often observe small, faint objects for extended periods of time, performing target tracking to continuously monitor the objects for hours or days—where long exposure becomes important and you end up with dozens or hundreds or thousands of satellite intersections in your image—and we can't forget, SpaceX isn't the only company wanting to launch its own mega-constellation. Amazon has its own plans too. OneWeb was going to be a thing, traditional geostationary satellite operators have their own aspirations in the area. LEO and VLEO are going to be flooded by this.
And then there's the other end of the spectrum where there are wide sky surveys (finding comets, astrometry, asteroid defence) that need to cover many degrees of arc, and even though they're taking still images, the satellite's presence is still undesirable—often these imaging surveys work by comparing images. If your comparisons are swamped by satellites moving in every different direction, and occluding objects you actually want to view, then your data becomes garbage.
You can make bold claims about the night sky being a “birthright” or whatever you want
I never used that term, but the dismissive tone used here irks me. I would say that the night sky is something collectively owned by humanity, and thus there needs to be representation from these stakeholders before large developments take place. Would you complain about an environmentalist group protesting the construction of a hotel in Yosemite National Park?
but there are many countries now that are considering high speed internet access a human right as well.
This circles back to my original point in my original comment that often the justification to allow these constellation to operate is the pragmatism that it provides a benefit to humanity—but there are other ways to provide high speed internet access to humans (and the focus should be on removing those barriers and monopolies!). But there's only one night sky.
This is all compounded by the fact that the naïve system and approval process the ITU uses for satellite approvals actually encourages reckless behaviour—satellite operators are forced to launch their satellites within a specific time period for them to legally use the frequencies they've been designated. Seems reasonable, but it break down when you apply the same rules to mega-constellations. Suddenly SpaceX has an incentive to throw as many satellites up their as quickly as they can and flood LEO to ensure they are assigned the frequency they've requested, even if the satellites break, even if they're v0.9, even if they flood astronomer's instruments. It's absurd.
The term “birthright” came from Carolyn Porco, an imaging team leader at NASA, from this article I found by searching for Dr. Marco Langbroek on Twitter. I assumed that Porco’s stance is the one...
I never used that term, but the dismissive tone used here irks me.
The term “birthright” came from Carolyn Porco, an imaging team leader at NASA, from this article I found by searching for Dr. Marco Langbroek on Twitter. I assumed that Porco’s stance is the one you were intimating, but maybe I misinterpreted.
Edit:
Would you complain about an environmentalist group protesting the construction of a hotel in Yosemite National Park?
That couldn’t happen unless Yosemite’s designation as a national park were changed, because there is already a system of governance that deals with land use in the United States. The issue of allocating resources like the “sky” is still something that I guess we need to nail down better, in your opinion? Or are you totally opposed to communication satellites at all?
The difference is the huge change in scale and that it's one company acting more-or-less unilaterally. If your three roommates each have one cat, you might not get very far complaining about it;...
The difference is the huge change in scale and that it's one company acting more-or-less unilaterally. If your three roommates each have one cat, you might not get very far complaining about it; but if one of them brings thirty cats into the apartment that's different.
I think your analogy raises a good rhetorical point to pick on. Isn’t it more like if your roommate brought home thirty cats into your apartment, granted your apartment was the size of a football...
I think your analogy raises a good rhetorical point to pick on. Isn’t it more like if your roommate brought home thirty cats into your apartment, granted your apartment was the size of a football field (forgive my not having access to the exact analogical dimensions of cat:apartment::satellite:earth)? Unless you have an hypersensitivity to cat dander or something (the analogical equivalent to being an astronomer), are you really going notice the cats if you aren’t looking for them?
Not quite correct. The main metric for satellites in LEO isn't about the space available, it's about the intersectionality that the satellites introduce via their velocity—the fact they're...
Not quite correct. The main metric for satellites in LEO isn't about the space available, it's about the intersectionality that the satellites introduce via their velocity—the fact they're travelling at 27,000km/h.
If we want to extend the analogy to absurd proportions to be technically correct—you have 30 cats in an apartment the size of the football field, but they're running around you at 100km/h, and occasionally crashing into your stuff. They also never sleep.
OK, thanks for extending the analogy, that paints a better picture, though I’d prefer to have real numbers and have a more objective sense of the magnitude of the damage that the constellation...
OK, thanks for extending the analogy, that paints a better picture, though I’d prefer to have real numbers and have a more objective sense of the magnitude of the damage that the constellation might do because I still don’t think I have a sense of that. I feel like I just have anecdotes from impartial critics, and also from impartial supporters of SpaceX, and it seems like someone who really knew about the science of all this could easily explain it.
The exact details of the analogy don't matter. The point is simply this: Not complaining about a problem when it's small doesn't set a precedent that means you can't complain about it when it gets...
The exact details of the analogy don't matter. The point is simply this: Not complaining about a problem when it's small doesn't set a precedent that means you can't complain about it when it gets larger.
And let's be realistic: even undarkened, these satellites are hardly killing astronomy. Previous satellites have even been a preferred target for amateur astronomers. Remember that just a couple...
And let's be realistic: even undarkened, these satellites are hardly killing astronomy. Previous satellites have even been a preferred target for amateur astronomers.
Remember that just a couple years ago people were disappointed they'd no longer be able to spot Iridium flares.
I think you'll find the same people who are disappointed Iridium satellites no longer flair do not heavily intersect with the ones who perform professional astronomy, in fact it's quite the...
I think you'll find the same people who are disappointed Iridium satellites no longer flair do not heavily intersect with the ones who perform professional astronomy, in fact it's quite the opposite—and most professional astronomers are not interested in targeting satellites, they consider them a nuisance.
"From my point of view it is frustrating when you have to delete 25 per cent of your pictures during an imaging session. I'm a bit afraid of our future view of the night sky when there are 10,000 of them in orbit."
That's a significant reduction in imaging capability.
Yes, I think you're right on both counts. I was replying in the context of amateur astronomers, but I recognize that professional astronomers will feel differently. Thank you for providing a...
I think you'll find the same people who are disappointed Iridium satellites no longer flair do not heavily intersect with the ones who perform professional astronomy, in fact it's quite the opposite—and most professional astronomers are not interested in targeting satellites, they consider them a nuisance.
Yes, I think you're right on both counts. I was replying in the context of amateur astronomers, but I recognize that professional astronomers will feel differently.
It already is.
Thank you for providing a source. And I don't mean to sound dismissive as I am still open to the idea, but I didn't find the read particularly convincing. Long-exposure images are certainly the most likely to be affected, but it's not clear to me that this is common to a large number of astronomers, in terms of location or niche.
edit: I've removed a line questioning this astronomer's authority to speak on the topic, because that wasn't very fair.
To explain that, much of the frustration I've heard has been over the actual launches and the initial climbing orbits. I know those will be rough for a while but they won't be permanent. Most of the photos of streaking I've seen appear to be from launches, or flares.
I also feel that if the situation were as bad as suggested, there'd be significant pushback from larger astronomical groups and observatories. I confide my lack of expertise on the topic, but I usually look to experts to stay informed. I haven't heard serious concern from those I follow such as Phil Plait, Scott Manley, or even groups such as the Planetary Society. They surely know more of the topic than I do, so why aren't they posting about concern?
Another factor is that there are regulatory boards in place to help prevent these problems. I understand the idea that they may be outdated, but I also try to give some credit to other people. I have to imagine they're well-educated on the topic, and are probably just as concerned as anybody else about polluting the night sky.
I don't want to sound like a climate change denier. We all know the argument: "It doesn't exist; it exists but it's not human-caused; okay fine it's human-caused but there's nothing we can do about it". I don't want to be that guy. This is just the skepticism I've honed about political topics over the years.
But I want to be clear: if there was a strong consensus within the scientific community, I would switch sides in a heartbeat. I haven't seen the evidence yet that I should be alarmed, but maybe I will in the future, and I'm open to that.
As a someone once told me: "If you never want to be wrong, be willing to change your mind".
I hope that explains how I've come to this view, and that it's not simply indifference to the topic.
There is significant pushback, but it simply isn't being listened to. IAU Statement on satellite constellations LSST statement More from LSST Analysis from Harvard astronomer on the impacts...
I also feel that if the situation were as bad as suggested, there'd be significant pushback from larger astronomical groups and observatories. I confide my lack of expertise on the topic, but I usually look to experts to stay informed. I haven't heard serious concern from those I follow such as Phil Plait, Scott Manley, or even groups such as the Planetary Society. They surely know more of the topic than I do, so why aren't they posting about concern?
There is significant pushback, but it simply isn't being listened to.
I can find more examples if you would like. There absolutely is a scientific consensus that these constellations will increasingly be problematic for ground based observatories. Many professional astronomers rely on these to do their science, and they are often great public investments and examples of international collaboration. Keep in mind too that Starlink plans to launch upwards of 30,000 of these - even if the problems now are able to be mitigated by changing observing strategies, they certainly won't be in the future.
Based on the article, it seems that SpaceX is listening and they are doing something to fix the problem? Maybe not fast enough for some. It seems like this debate has gotten excessively binary, as...
Based on the article, it seems that SpaceX is listening and they are doing something to fix the problem? Maybe not fast enough for some.
It seems like this debate has gotten excessively binary, as if the only two choices were to ignore the complaints entirely or to cancel the project. The people actually involved (rather than us discussing it on the sidelines) seem to be looking at a lot of alternatives.
I've reviewed each of these links now. Thanks again for providing them. I found the LSST's argument to be quite useful, as they ran simulations of a fully deployed constellation network. It's good...
I've reviewed each of these links now. Thanks again for providing them.
I found the LSST's argument to be quite useful, as they ran simulations of a fully deployed constellation network. It's good to see the numbers which paint a much more objective picture.
The worst case is bad. 30% of images affected is a serious hindrance to this program. Forgetting amateur astronomy for a moment, it seems this would most affect night sky cataloging projects. Especially those with long exposures and wide fields of view.
Though I do understand the 30% impact is before some of the mitigations they propose. eg. darkening satellites, splitting exposures, upgrading imaging algorithms, and implementing scheduling which is aware of satellite positioning. Through a combination of these efforts, I believe the overall impact could be severely reduced, by one or two orders of magnitude. It is a lot of work though, and potentially needs to be replicated by many ground-based observatories.
I would be very curious to hear if the satellite that was darkened as an experiment had the intended effect on imaging equipment. It was touched on briefly in one of the papers linked, but I'm unsure if it referred to the same experiment.
It seems the periods most affected are dusk and dawn, which is a comment I've heard before. I would have thought these periods to be less valuable for telescope time, but one of the points raised was that these periods are actually useful for detecting near-Earth asteroids. That's an interesting perspective, and a second area of research which may be impacted.
I didn't understand everything in the paper by Jonathan C. McDowell, but I did learn some. It actually left me feeling better about the lifecycle of satellites in LEO, due to their limited lifespans. Per his analysis it seems the layer C satellites will be visible under certain conditions (notably at high altitudes in Europe, and during specific periods). However layer C includes the largest number of satellites and operates at the lowest altitude, which explains why they're the most concerning.
This paper also linked a document from AAS which I will include here, just to add to the collection of links above.
I feel I have a better read on the situation having explored these documents. Admittedly I still think the original contention ("ruining ground-based astronomy") is going too far, but I do believe this will have a negative effect on multiple ground-based projects unless mitigating steps can be implemented. That seems like important research that should be prioritized before these satellite launches are scaled up.
Ping @gpl and @emdash. Apologies for the bump to everyone else.
That quote is from an amateur astronomer. They don’t have to delete exposures that happen to capture an artificial satellite. That is their choice. This is the equivalent of me taking photos in a...
That quote is from an amateur astronomer. They don’t have to delete exposures that happen to capture an artificial satellite. That is their choice. This is the equivalent of me taking photos in a public space and complaining that I have to delete 25 percent of my photos because there were other people there that I happened to capture. We have to balance our own rights against the rights of others—that’s part and parcel of being a social animal within a society. I agree that we can try to collectively make decisions that affect our species positively, but I’m not convinced that the population of astronomers should have the right to veto developments like Starlink. I feel like there has to be a civil way to find consensus.
Huh? I'd hazard a bet that to achieve the science they after, they probably do have to delete them because the data is now either garbage or significantly compromised. Saying it's "their choice"...
That quote is from an amateur astronomer. They don’t have to delete exposures that happen to capture an artificial satellite. That is their choice.
Huh? I'd hazard a bet that to achieve the science they after, they probably do have to delete them because the data is now either garbage or significantly compromised. Saying it's "their choice" to delete them comes off like victim blaming actually. If someone sits down on a park bench next to you, and lights up a cigarette, you don't have to move. It's your choice.
Ok, so what is the solution to this? The reasoning I'm seeing so far seems to argue that this shouldn't happen; I don't see them applying solutions and at the very least SpaceX is trying to limit...
Ok, so what is the solution to this? The reasoning I'm seeing so far seems to argue that this shouldn't happen; I don't see them applying solutions and at the very least SpaceX is trying to limit the reflection of these devices instead of telling everyone to get stuffed. I love space imaging (I work in remote sensing) so I am very sympathetic to the plight of the astronomers here, but I also don't see not using LEO and VLEO satellites and constellations as an option.
The ITU was vote-stuffed by SpaceX and makes questionable decisions themselves, and the U.S. FCC does not consult the rest of the world when asking about these sorts of things anyway—when this is...
The ITU was vote-stuffed by SpaceX and makes questionable decisions themselves, and the U.S. FCC does not consult the rest of the world when asking about these sorts of things anyway—when this is arguably a global issue. Something as consequential as a potentially 30,000-satellite constellation deserves more attention to due process than it's actually been given.
That's a great and complex question that I don't have the answer to. It's one that needs input from likely nearly every country on Earth, professions that make use of the sky for their work, and...
That's a great and complex question that I don't have the answer to. It's one that needs input from likely nearly every country on Earth, professions that make use of the sky for their work, and an updated Outer Space Treaty to consider commercial interests.
None of which are happening—and a commercial entity is taking advantage of that situation for profit. Which circles back to my point about why this whole this is a big problem.
A lot of things about satellite launches are regulated, but I guess this isn't one of them. This problem should have been anticipated, but I'm glad they're fixing it.
A lot of things about satellite launches are regulated, but I guess this isn't one of them.
This problem should have been anticipated, but I'm glad they're fixing it.
From the article:
[...]
It's remarkable that a single company can unilaterally obstruct the night sky and potentially ruin the future of ground-based astronomy.
Exactly, and that's why SpaceX fanboys will just never understand or side with people who disagree with this idea: because in their mind, SpaceX and Elon Musk are the exemplar of lawful good, and justify the outcome pragmatically by saying "millions of people will be able to get internet". It's not about the outcome, or whether the company is intrinsically good, it's about the lack of consultation and discussion that's taken place, and the commercialisation of the night sky which is no doubt something owned by all of humanity.
There are already a number of less dense satellite constellations providing telecommunications services. As far as I can tell, a lot of people seem to take issue with SpaceX simply because it is more well known, and because of Elon Musk’s involvement. Did the same people who are coming out against Starlink come out to protest the other telecommunications satellite constellations that have been launched? What about the launching of the ISS? What about sky writing, airplane banner towing, or airplanes in general? I think it’s hard to take people seriously when they attack Musk and his ventures personally, and don’t apply the same criticism to more obscure entities.
I do feel bad if your amateur astronomy projects are affected by artificial satellites, but at this point, I feel like that is a luxury that individuals can forego for the benefit of all the people who will gain access to higher bandwidth internet connections. Why does your astronomy hobby outweigh rural demand for communication? Are there critics who actually have put forth a rational critique of the standards bodies who regulated and approved Starlink (and other constellations)?
No, people take issue because Starlink type constellations are fundamentally different than on of the examples you listed here.
This is a huge problem for actual scientific collaborations, many of which are publicly funded endeavors being handicapped for a private venture. I am a cosmology PhD student, and I can unequivocally say that Starlink type constellations present a tremendous problem for ground based observations, and it is not as easy as just "sampling around them". These satellites are so bright that they often completely ruin exposures that are trying to image extremely faint objects Megaparsecs away. I have been attending a decent number of talks on possible methods to work around this, but the general consensus in the field is that as these things become more common the problem will be intractable.
I know it can seem like an overreaction because the satellites are small and the sky is big, but please, please believe professional astronomers when they say this is a whole different type of problem than what we've seen before. Professional observations need large patches of the sky for long times with high sensitivity.
I personally don't think a single company should be able to take advantage of a broken regulatory process and completely pollute the night sky, seriously hampering the work of large, publicly funded scientific collaborations. It boils down to sacrificing the commons for private interest.
EDIT:
None of this to mention the impact on other wavelengths, nor Musk's absolutely inadequate response that "the future of astronomy is space based telescopes, anyway".
It's not quite as simple as that though: SpaceX is unique because they're the first company to have the capacity and capability to launch tens of thousands of satellites. They own the railroad and the town at the other end, and they're taking advantage of an antiquated approval process that was neither designed or intended to approve mega-constellations. That's why this is problematic. Their success has made them a titan of the industry, and that's often where problems lie. Companies get successful, they get big, then they get too powerful. We've seen it time and time again—take a look at the tech industry right now, as a good example.
Prior to this the largest satellite constellations were the Iridium constellation, which actually nearly failed as a business before, and had a sum total of < 80 satellites in orbit. SpaceX already has over 400, and potentially is estimating up to 30,000. That's a magnitude of scale difference.
I've followed SpaceX (and many other spaceflight companies!) for a number of years, when they were launching puny rockets that had parachute recovery systems in them, from Kwaj in the Marshall Islands—and believe it or not I'm actually rather enamoured with what they do, and generally supportive of their actions (minus launching cars into space, and Musk himself, who is an all-around douchebag)—so yes, there are very valid reasons apart from Musk-is-popular-and-fun-to-mock to question Starlink.
This is a heavy dismissal of a serious issue. It's not just amateur astronomy that's important, it's professional astronomy—and darkening the satellites doesn't solve the problem, they're still there and will still appear in many large sky surveys, especially ones that don't monitor visible light. I think you'll find many astronomers and professional scientists who are frustrated about the lack of consultation they've been invited to, SpaceX appears to only be doing it after the fact. See Marco Langbroek on Twitter, for example.
Presumably professional astronomers who have access to the resources to do continuous observation of the sky can sample around the satellites? There is a lot of sky up there, and even tens of thousands of satellites do not obstruct very much of it at any given point in time. For those who are doing long exposures pointing at the same point for extended periods, that is a larger problem, but presumably already has the issue of objects like the ISS transiting across whatever object further out there that you are focusing on.
You can make bold claims about the night sky being a “birthright” or whatever you want, but there are many countries now that are considering high speed internet access a human right as well. How can we resolve such conflicts of interest on a global scale when our species is still regulating activities that have global impact via non-global governance?
No, in fact, commonly it's the opposite way around! Their needs are often so precise and strict that deviations from the intended conditions result in completely garbage data, as per the comment from an (amateur, apparently who's points don't count?) astronomer I linked in my reply to @Wes:
Professional astronomers will often observe small, faint objects for extended periods of time, performing target tracking to continuously monitor the objects for hours or days—where long exposure becomes important and you end up with dozens or hundreds or thousands of satellite intersections in your image—and we can't forget, SpaceX isn't the only company wanting to launch its own mega-constellation. Amazon has its own plans too. OneWeb was going to be a thing, traditional geostationary satellite operators have their own aspirations in the area. LEO and VLEO are going to be flooded by this.
And then there's the other end of the spectrum where there are wide sky surveys (finding comets, astrometry, asteroid defence) that need to cover many degrees of arc, and even though they're taking still images, the satellite's presence is still undesirable—often these imaging surveys work by comparing images. If your comparisons are swamped by satellites moving in every different direction, and occluding objects you actually want to view, then your data becomes garbage.
I never used that term, but the dismissive tone used here irks me. I would say that the night sky is something collectively owned by humanity, and thus there needs to be representation from these stakeholders before large developments take place. Would you complain about an environmentalist group protesting the construction of a hotel in Yosemite National Park?
This circles back to my original point in my original comment that often the justification to allow these constellation to operate is the pragmatism that it provides a benefit to humanity—but there are other ways to provide high speed internet access to humans (and the focus should be on removing those barriers and monopolies!). But there's only one night sky.
This is all compounded by the fact that the naïve system and approval process the ITU uses for satellite approvals actually encourages reckless behaviour—satellite operators are forced to launch their satellites within a specific time period for them to legally use the frequencies they've been designated. Seems reasonable, but it break down when you apply the same rules to mega-constellations. Suddenly SpaceX has an incentive to throw as many satellites up their as quickly as they can and flood LEO to ensure they are assigned the frequency they've requested, even if the satellites break, even if they're v0.9, even if they flood astronomer's instruments. It's absurd.
The term “birthright” came from Carolyn Porco, an imaging team leader at NASA, from this article I found by searching for Dr. Marco Langbroek on Twitter. I assumed that Porco’s stance is the one you were intimating, but maybe I misinterpreted.
Edit:
That couldn’t happen unless Yosemite’s designation as a national park were changed, because there is already a system of governance that deals with land use in the United States. The issue of allocating resources like the “sky” is still something that I guess we need to nail down better, in your opinion? Or are you totally opposed to communication satellites at all?
The difference is the huge change in scale and that it's one company acting more-or-less unilaterally. If your three roommates each have one cat, you might not get very far complaining about it; but if one of them brings thirty cats into the apartment that's different.
I think your analogy raises a good rhetorical point to pick on. Isn’t it more like if your roommate brought home thirty cats into your apartment, granted your apartment was the size of a football field (forgive my not having access to the exact analogical dimensions of cat:apartment::satellite:earth)? Unless you have an hypersensitivity to cat dander or something (the analogical equivalent to being an astronomer), are you really going notice the cats if you aren’t looking for them?
Not quite correct. The main metric for satellites in LEO isn't about the space available, it's about the intersectionality that the satellites introduce via their velocity—the fact they're travelling at 27,000km/h.
If we want to extend the analogy to absurd proportions to be technically correct—you have 30 cats in an apartment the size of the football field, but they're running around you at 100km/h, and occasionally crashing into your stuff. They also never sleep.
OK, thanks for extending the analogy, that paints a better picture, though I’d prefer to have real numbers and have a more objective sense of the magnitude of the damage that the constellation might do because I still don’t think I have a sense of that. I feel like I just have anecdotes from impartial critics, and also from impartial supporters of SpaceX, and it seems like someone who really knew about the science of all this could easily explain it.
The exact details of the analogy don't matter. The point is simply this: Not complaining about a problem when it's small doesn't set a precedent that means you can't complain about it when it gets larger.
You can complain about any problem no matter the size. I’d still rather have objective measurement of the size, though.
And let's be realistic: even undarkened, these satellites are hardly killing astronomy. Previous satellites have even been a preferred target for amateur astronomers.
Remember that just a couple years ago people were disappointed they'd no longer be able to spot Iridium flares.
I think you'll find the same people who are disappointed Iridium satellites no longer flair do not heavily intersect with the ones who perform professional astronomy, in fact it's quite the opposite—and most professional astronomers are not interested in targeting satellites, they consider them a nuisance.
It already is.
That's a significant reduction in imaging capability.
Yes, I think you're right on both counts. I was replying in the context of amateur astronomers, but I recognize that professional astronomers will feel differently.
Thank you for providing a source. And I don't mean to sound dismissive as I am still open to the idea, but I didn't find the read particularly convincing. Long-exposure images are certainly the most likely to be affected, but it's not clear to me that this is common to a large number of astronomers, in terms of location or niche.
edit: I've removed a line questioning this astronomer's authority to speak on the topic, because that wasn't very fair.
To explain that, much of the frustration I've heard has been over the actual launches and the initial climbing orbits. I know those will be rough for a while but they won't be permanent. Most of the photos of streaking I've seen appear to be from launches, or flares.
I also feel that if the situation were as bad as suggested, there'd be significant pushback from larger astronomical groups and observatories. I confide my lack of expertise on the topic, but I usually look to experts to stay informed. I haven't heard serious concern from those I follow such as Phil Plait, Scott Manley, or even groups such as the Planetary Society. They surely know more of the topic than I do, so why aren't they posting about concern?
Another factor is that there are regulatory boards in place to help prevent these problems. I understand the idea that they may be outdated, but I also try to give some credit to other people. I have to imagine they're well-educated on the topic, and are probably just as concerned as anybody else about polluting the night sky.
I don't want to sound like a climate change denier. We all know the argument: "It doesn't exist; it exists but it's not human-caused; okay fine it's human-caused but there's nothing we can do about it". I don't want to be that guy. This is just the skepticism I've honed about political topics over the years.
But I want to be clear: if there was a strong consensus within the scientific community, I would switch sides in a heartbeat. I haven't seen the evidence yet that I should be alarmed, but maybe I will in the future, and I'm open to that.
As a someone once told me: "If you never want to be wrong, be willing to change your mind".
I hope that explains how I've come to this view, and that it's not simply indifference to the topic.
There is significant pushback, but it simply isn't being listened to.
I can find more examples if you would like. There absolutely is a scientific consensus that these constellations will increasingly be problematic for ground based observatories. Many professional astronomers rely on these to do their science, and they are often great public investments and examples of international collaboration. Keep in mind too that Starlink plans to launch upwards of 30,000 of these - even if the problems now are able to be mitigated by changing observing strategies, they certainly won't be in the future.
Thank you for the links. I'll spend some time reviewing these over the next few days.
Based on the article, it seems that SpaceX is listening and they are doing something to fix the problem? Maybe not fast enough for some.
It seems like this debate has gotten excessively binary, as if the only two choices were to ignore the complaints entirely or to cancel the project. The people actually involved (rather than us discussing it on the sidelines) seem to be looking at a lot of alternatives.
I've reviewed each of these links now. Thanks again for providing them.
I found the LSST's argument to be quite useful, as they ran simulations of a fully deployed constellation network. It's good to see the numbers which paint a much more objective picture.
The worst case is bad. 30% of images affected is a serious hindrance to this program. Forgetting amateur astronomy for a moment, it seems this would most affect night sky cataloging projects. Especially those with long exposures and wide fields of view.
Though I do understand the 30% impact is before some of the mitigations they propose. eg. darkening satellites, splitting exposures, upgrading imaging algorithms, and implementing scheduling which is aware of satellite positioning. Through a combination of these efforts, I believe the overall impact could be severely reduced, by one or two orders of magnitude. It is a lot of work though, and potentially needs to be replicated by many ground-based observatories.
I would be very curious to hear if the satellite that was darkened as an experiment had the intended effect on imaging equipment. It was touched on briefly in one of the papers linked, but I'm unsure if it referred to the same experiment.
It seems the periods most affected are dusk and dawn, which is a comment I've heard before. I would have thought these periods to be less valuable for telescope time, but one of the points raised was that these periods are actually useful for detecting near-Earth asteroids. That's an interesting perspective, and a second area of research which may be impacted.
I didn't understand everything in the paper by Jonathan C. McDowell, but I did learn some. It actually left me feeling better about the lifecycle of satellites in LEO, due to their limited lifespans. Per his analysis it seems the layer C satellites will be visible under certain conditions (notably at high altitudes in Europe, and during specific periods). However layer C includes the largest number of satellites and operates at the lowest altitude, which explains why they're the most concerning.
This paper also linked a document from AAS which I will include here, just to add to the collection of links above.
I feel I have a better read on the situation having explored these documents. Admittedly I still think the original contention ("ruining ground-based astronomy") is going too far, but I do believe this will have a negative effect on multiple ground-based projects unless mitigating steps can be implemented. That seems like important research that should be prioritized before these satellite launches are scaled up.
Ping @gpl and @emdash. Apologies for the bump to everyone else.
That quote is from an amateur astronomer. They don’t have to delete exposures that happen to capture an artificial satellite. That is their choice. This is the equivalent of me taking photos in a public space and complaining that I have to delete 25 percent of my photos because there were other people there that I happened to capture. We have to balance our own rights against the rights of others—that’s part and parcel of being a social animal within a society. I agree that we can try to collectively make decisions that affect our species positively, but I’m not convinced that the population of astronomers should have the right to veto developments like Starlink. I feel like there has to be a civil way to find consensus.
Huh? I'd hazard a bet that to achieve the science they after, they probably do have to delete them because the data is now either garbage or significantly compromised. Saying it's "their choice" to delete them comes off like victim blaming actually. If someone sits down on a park bench next to you, and lights up a cigarette, you don't have to move. It's your choice.
But you'll probably want to.
Well, I think we’d need some real amateur astronomers to weigh to set the record straight.
Ok, so what is the solution to this? The reasoning I'm seeing so far seems to argue that this shouldn't happen; I don't see them applying solutions and at the very least SpaceX is trying to limit the reflection of these devices instead of telling everyone to get stuffed. I love space imaging (I work in remote sensing) so I am very sympathetic to the plight of the astronomers here, but I also don't see not using LEO and VLEO satellites and constellations as an option.
It wasn’t unilateral. They had to get approval from the US Federal Communications Commission and the International Telecommunication Union.
The ITU was vote-stuffed by SpaceX and makes questionable decisions themselves, and the U.S. FCC does not consult the rest of the world when asking about these sorts of things anyway—when this is arguably a global issue. Something as consequential as a potentially 30,000-satellite constellation deserves more attention to due process than it's actually been given.
So, how can the global regulatory situation be improved?
That's a great and complex question that I don't have the answer to. It's one that needs input from likely nearly every country on Earth, professions that make use of the sky for their work, and an updated Outer Space Treaty to consider commercial interests.
None of which are happening—and a commercial entity is taking advantage of that situation for profit. Which circles back to my point about why this whole this is a big problem.
A lot of things about satellite launches are regulated, but I guess this isn't one of them.
This problem should have been anticipated, but I'm glad they're fixing it.