Insane SpaceX Starlink Satellite Train Flyover Video (Update)
Keith’s note: I am wondering if the satellite spacing is some sort of binary message to Richard Branson or Jeff Bezos … 😉
Keith’s 27 May update: I got this note from a reader, “cmdr2”:
“I found out about the “Starlink satellite train” phenomenon yesterday, and I was very excited to find out when it would pass over my city. In case this is helpful to share with your readers, I’ve written a tool to show when the Starlink train will pass over your city. This tool essentially automates the steps that seemed to be working for redditors on r/space. A number of them have confirmed that they managed to see it using this tool. The original instructions were graciously posted by u/CreeperIan02 on reddit, and it involves a fair bit of data crunching to figure out. This tool simplifies that. It is based on Jens Satre’s original code, modified for Starlink’s data and a simpler interface. For your reference, the original instructions posted on reddit (that this tool automates): I’ve updated the tool to use the new tracking data shared by Marco yesterday, and only show timings 90 mins after sunset or 90 mins before sunrise (to improve accuracy).”
Keith’s 29 May update: This internal letter was sent out by Kevin B. Marvel, Executive Officer, American Astronomical Society to trustees and other members:
“Dear Trustees,
As many of you are aware, Elon Musk’s company SpaceX has launched some satellites to provide Internet service from space to ground. They are quite visible and videos of their night time appearance have been widely disseminated on the Internet, with a wide range of responses.
Although much data still needs to be gathered about their impact on astronomical research from the ground and the general quality of the night sky for all, the Twitterverse is exploding right now on the matter and calls for prompt action are now descending on our leadership, our committees and the Executive Office.”
Full Letter after the link
“At times like these, it is important to let folks know what we are doing and that we are taking a reasoned and informed approach to responding instead of responding quickly without complete information and understanding. This is why our positions are widely respected in the policy environment and our reputation as balanced and careful players in the policy space remains secure.
I am writing to let you know what the AAS is currently doing and will also share this information with our AAS Agents for broader dissemination.
First off, we have a committee of experts on Light Pollution, RFI and Space Debris and they’ve been tracking this since the beginning (and some before) and are formulating a position statement for the Board to consider. I’m not sure they will be done by the June meeting, but I believe they are working toward that goal…they’ve kept Megan informed as they’ve proceeded (and us here in the EO). They are planning to use the Starlink issue to speak more broadly about the impact of satellites on research and how negative impacts can be minimized along with other issues…but will not focus exclusively on the Starlink issue…far better to establish a significant marker using the notoriety of the current situation.
The CAPP has also been brought in on the issue and are talking up the matter via email. Their thinking will inform any statement and any action proposed for the AAS to take as well as subsequent policy activities.
AAS Deputy Executive Officer and Director for Public Policy, Joel Parriott has been actively tracking the issue and issued a tweet a few hours ago on the matter.
So, if you get any queries along the lines of ‘what is the AAS doing about this’, now you know.
Please refer any specific questions to Joel or myself. We will respond as best we are able given the rapid development of this matter and our other pending duties prior to the AAS meeting in St. Louis.
Best.
Kevin.”
Starlink, and other similar constellations, are going to becoming a giant pain for astronomers. There needs to be regulations, otherwise ground-based astronomy is going to become completely non-viable for scientific research purposes.
This might be a good time for SpaceX to review the principles of optical signature reduction…
That could help for people who like looking at stars. But not for serious astronomy. A telescope like Keck can go down to 24th magnitude with a little work and a one hour integration. That’s 16 million times fainter than someone with good eyes can see.
Musk has already tasked his engineers to reduce the albedo of their production satellites.
That said, orbit raising alone should dim them to 64% of their initial brightness, and turning their solar array to the operational position will dim them more. Guessing some radio-transparent coating on the 4 phased arrays would be next.
Maybe not.. The 200″ Hale Telescope on Palomar has the Large Format Camera which covers 24 arc minutes – that’s 7 km at a range of 1000 km, and with a 7km/s orbital velocity, the satellite is in the field of view of the telescope for 1 second. The orbits are predictable, and I assume they have some sort of mechanical or electronic shutter for the sensor – assuming that the orbit plane crosses the field of view for the telescope, which it would do for about 100 seconds, twice a day. If the 60 satellites in the current launch are spread out evenly, they’re about 700km apart, or 100 seconds.
Yes, it makes scheduling a bit more complex when you have 10,000 of these up, but similar problems exist with airplanes, which are substantially less predictable.
And that’s assuming you don’t want the satellite anywhere in the FOV of the sensor – as opposed to just ignoring pixels that have the spacecraft (or airplane) in them.
It’s not a bit more complex, it’s unmanageably complex. Telescopes (well, classically scheduled like Palomar) aren’t managed by some grand software scheduling system, they are pretty much pointed by hand at the will of the observer, and exposures are commanded manually. Just dealing with the required shutdowns for laser guide stars (driven by defense satellites) is a pain. Palomar has significant issues with many per night unscheduled military aircraft flyovers. You basically just suck it up and scrub the satellite and aircraft trails, and do multiple exposures. God help you if they are all over every frame.
It will probably help that these satellites will be in strings in a limited number of very visible orbital planes. But if Starlink pays off the R&D costs of Starship/Super Heavy with Starlink it will make it very cheap to transport telescopes into space and put them on the Moon. Of course the cost of building those telescopes will need to be drastically reduced, but expect once astronomers realize they will be easily deployed and service in orbit the costs will fall very quickly.
I thought I read that the Moon is pretty much out of favor as a telescope location due to interference from its atmosphere. I’m sure it can be mitigated but I thought the opinion is that having to deal with it at all negates whatever benefit there is of having a stationary platform on the lunar surface.
But you raise a good point that if the cost for launching telescopes and the humans/robots to service them drops dramatically countries will likely begin building larger and more elaborate space telescopes.
The dust is the basic problem, but we really don’t know anything about it. It may just be a case of putting it on a platform a few meters off the surface, or putting an electric charge on instruments that repels the lunar dust, or …. It also may only be a problem during sunset/sunrise and not an issue at other times of the lunar day. Its one of many reasons we need to learn more about the surface conditions on the Moon.
CCDs used in modern telescopes are read multiple times during an exposure. Satellite streaks are easily removed with software.
No, that’s not exactly true. You’re describing “lucky imaging”, which is a common way to deal with atmospheric blurring. But it only works well for bright objects. CCDs have a certain amount of readout noise, so long integration times are still common when observing faint objects. The state of the art is improving, but you still aren’t going to get close to 20th magnitude with rapid readouts.
And 20th magnitude is wicked bright by modern extragalactic standards. That’s just a minute exposure on a small (meter-ish) telescope. Typical exposure times are still 30 minutes or so in the optical.
I was going to say it would be ok if SpaceX offered free launches to a whole bunch of new, orbital telescopes. Or even started something like the Keck Foundation to fund those observatories. But then I remembered how valuable all those small telescopes used by really skilled amateurs are. And how it’s nice just to be able to see the star, regardless of scientific research. (By the way, there were a nice pair of images on Astronomy Picture of the Day last week. Some city in China decided to turn the lights out, to see what the sky looked like with and without them. The difference was impressive.)
Not so much for the pros. Those big telescopes have such a narrow field of view I would think anything crossing their field of view is small.
This is why I think SpaceX is going to find it pretty hard politically to get the full constellation up. This wouldn’t be just US night skies and astronomy that get heavily affected – other countries would be dealing with it as well.
I do not think so as the value of the information services the satellites will provide will outweigh the attempts to block it. On the other hand nations that seek to control the access their population has to news and information will be displeased at this new powerful symbol of personal freedom. The antennas that link to it will also be far easier to hide than existing satellite antennas in nations where their ownership will be illegal.
The ground antennas will cost at least $300 each, assuming the most optimistic SpaceX cost reductions on those prove possible. IIRC Musk has said they’re counting on most of the SpaceX bandwidth being bought by ISPs rather than end users, and ISPs absolutely can be pressured and prevented from using it by their national governments.
Don’t underestimate the desire of those in countries that are locked down to have free access to information, especially those with some money. Satellite antennas are expensive and illegal, but many find a way to get them.
You’re raising a whole lot of legal issues. In some abstract, or even tangible, sense, the value of the information services may be high. But every country affected would have to agree about that. And astronomy is a convenient for countries which do not want free and unrestricted access to the internet. I note that China has invested in a number of very high end observatories, and might feel their investment has been compromised by such a constellation of satellites. That sounds like grounds for a lawsuit to me. Potentially not a successful one, especially given the lack of precedents and international law. But dealing with that sort of thing can be expensive.
The number of satellites, and the number of orbital planes (I thought it was closer to 40 than the nine you mentioned in another comment) makes me worry about orbital traffic. I’m not inclined to be pessimistic about run-away orbital debris disasters. But avoiding collisions is going to take more work, and there are issues with deorbiting spacecraft before they fail, and whether or not making someone to maneuver to avoid a collision is “interference” in the sense of the Outer Space Treaty. And, before someone says that’s why we need a Space Force, I’ll point out the lack of jurisdiction. This will probably require a body of treaties and international laws, to produce something like admiralty law. Then the Space Force would have jurisdiction to deal with traffic violations.
I read somewhere that the satellites will have the ability to avoid collisions on their own, but we will see. It will however be a challenge in terms of managing the Constellation successfully.
In terms of lawsuits, under Article VI of the OST the U.S. government is the entity legally responsible, but the OST only allows for nations to work out disagreements by negotiations, so other than filing a complaint with the International Court in The Hague foreign nations have few options. Astronomers in the U.S. could probably sue the FCC, the legal entity responsible, for Licensing the Starlink Constellation, but it would be a weak case since such issues were suppose to be raised during the licensing process for the FCC to review. I am surprised that no one did so. But a good lawyer might be able to make a case selecting the right court that would at least get a hearing without being tossed out.
Good lawyers can do some amazing things. In this case, the Outer Space Treaty would not apply. I was considering the case of interference with a ground based observatory, not a spacecraft. (The interference would be _by_ but not _to_ a spacecraft.) That’s misconduct (a good lawyer would have to find a specific statute to invoke) which harms someone’s investment in ground based infrastructure (an observatory.)
That might only put it in the nuisance lawsuit range. But if memory serves, people have tried to sue the US government over not preventing global warming, citing economic harm from sea level rise. I don’t think that one went anywhere, but it did pay some lawyers. And made someone pay them. That’s really what nuisance lawsuits are all about: Adding to the cost of some project you want to stop, and trying to kill or delay it by making in less profitable.
Yes, but the OST is very clear about having the launching state, in this case the federal government be responsible for all liability associated with space activities by its nationals. So if someone sued SpaceX they would just show their FCC license and the Judge would tell the lawyer they need to sue the FCC. So the it would be taxpayer paying the FCC lawyers. Actually I hope some astronomy group does sue as it will illustrate the legal protection private entities have when engaged in space activities.
That’s true. I was thinking about the interference clause not the blanket responsibility of the launching state. Although NASA did refuse to pay that A$400 fine for littering which Esperance, Western Australia issued after Skylab came down…
But I think any legal cases need to be handled carefully. The current regulatory system inn the US doesn’t make much, and to the extent that it does, it mostly makes sense for geostationary communication satellites. A case about light pollution or orbital debris, dismissed because the Federal Communications Commission issued a license? I know that’s what would probably happen, but can you imagine the public reaction if that got significant press coverage? We’re probably better off letting the National Space Council straighten out the regulatory issues quietly, rather than Congress weigh in and try to “fix” things in response to a media circus.
You are correct. It is 40 Orbital planes in 3 shells, so they will be much more scattered.
This is a non-issue politically, every space power is going to want to launch more satellites, US military is already considering their own LEO constellations. Any attempt to limit the # of satellites launched is just not going to fly, especially considering the additional light they added is harmless. Yes, they will affect astronomy, but so did city lights, you don’t see governments banning city lights do you?
Not clear to me whether it is or isn’t a non-issue politically. The US military’s Project Westford in the early 1960s attempted to create an artificial ionosphere using millions of orbiting dipole antennas, and apparently (according to wikipedia) protests from astronomers (radio and optical) around the world were partly responsible for that technology being abandoned. The other factor mentioned was the advent of communications satellites. Also w.r.t. city lights, a quick google shows that observatories near some cities have managed to get restrictive lighting ordinances passed…
For city lights, it isn’t exactly about restricting lighting. The choice of lights (for the same apparent illumination without radiating over the entire spectrum), fixtures which make sure most of the light goes down rather than up, etc. can all make big differences for light pollution. But they are also expensive. That means it’s more of a debate about cost, not safety.
The local astronomy groups that go around to cities and businesses promoting “responsible” lighting point out to them that correctly shielded light fixtures waste less electricity and can therefore pay back in the long run. From what I have heard they have had some success in getting at least some lights converted, or at least convincing them to use more efficient fixtures on new installations. Here is an example of the type of brochure they hand out showing illustrations of good and bad fixtures. The cost difference is often minimal, at least for new installations.
https://www.darksky.org/our…
Unfortunately there is a new enemy now being dealt with – LED. Incandescent and other types of outdoor bulbs are increasing being replaced with LED bulbs that are often much brighter than the bulbs they are replacing because people aren’t paying attention to lumens, or even watt equivalents, they just get what fits. People think it’s a win-win because they are getting more light for less cost. In my neighborhood stargazing is not as good as it used to be because of so many bright LED backyard lights, it wasn’t nearly as bad when people were using incandescents. And I have seen the same trend recently in street lights which are now much brighter after switching to LED.
Project West Ford was protested because the Soviet is not trying to do the same, if Soviet has similar plans the protest would be a non-issue.
Right now China is planning at least 2, maybe 4 of their own constellations, OneWeb has big European investors such as Airbus, so I don’t see any UN debate on this matter would result in a resolution.
Besides, even if a law is to be passed, it may not apply to SpaceX since they already got their FCC and FAA license.
And finally, even if a law to limit # of satellites in orbit is to be passed, it would only give SpaceX more advantage since with Starship they can launch super massive satellites to compensate for the lack of numbers.
Unless I’m missing something, there was nothing to prevent the Soviet military from benefiting from the artificial ionosphere created by the US, so I wouldn’t think they’d seriously protest it other than for propaganda. Also protests apparently first came from the British, who I think were our friends… 😉
Fewer satellites in geosynchronous orbit, would seem to be a workable alternative… I imagine the trade off would be greater latency and likely lower bandwidth. So given that there seems to be an alternative I’d think political issues could affect this.
The astronomy and astrophysics community on Twitter has made this very clear. They’re up in arms again, just like they were about Starman/Roadster and just like they were about Peter Beck’s short-lived reflective satellite.
The satellites are at low altitude, so unless it’s near sunrise/sunset they will not be illuminated by sunlight.
That might make it easier on the astronomers, since they rarely observe at twilight and rarely point too close to the horizon. But I’d like to see some numbers before I’m convinced. Ground-based IR astronomy might be a concern, since those satellites don’t need to be in sunlight to be warm.
Ground based IR astronomy mostly uses near IR, right? Satellite thermal emission will be minimal there.
It’s mostly near IR, but that goes out to 5 microns and there are windows at longer wavelength people use fairly often (around 10 to 15 microns, I think.) An object at 300 K has its peak emissions at 9 microns, and a significant flux below 5 microns. But I’m not sure what the limiting magnitudes are or how it compares to emission from a relatively small satellite.
Is occultation of stars by the satellites less of an issue than than what they emit or reflect? Not obvious to me one way or the other…
I guess it would depend on the telescope, but I’m pretty sure occultations are much less of an issue. For an occultation, the spacecraft would actually have to pass in front of the star. Even if it were an unresolvably small angle to the side, it wouldn’t occult the star. But for emission or reflection, it just has to be as close to the star as the telescope’s angular resolution. Now, if we’re talking about a telescope actually resolve one of those spacecraft, I guess occultations would be a more serious issue.
Actually I believe in summer time they may be in sunlight much longer in the summer time. It looks like a 10PM EDT pass tonight will be visible.
I too have some concern on how this and future satellites of this ilk will affect Earth based astronomy but since it is now up there does anyone have any info on when to view these satellites while they are still nicely clustered?
That’s something I hadn’t thought of before. Those satellites are raising their orbit using electric propulsion. That makes orbital determination and tracking a very different proposition from a spacecraft which is just orbiting, subject to atmospheric drag, and perhaps making the occasional maneuver. That’s a solvable (and solved) problem. But someone in the US Strategic Command gets to keep updated orbital information on about 20,000 spacecraft or pieces of spacecraft. That’s not something you can do by hand, and I’m not sure if their software can automatically deal with a spacecraft under electric propulsion. And now they’ve got sixty of them to deal with? I have no doubt they can handle it, and make whatever software changes are necessary to automate the process. But they could be in for a bad week and lots of overtime.
Looking at the video it seems that the slightly different orbital altitudes is already spreading them out linearly. I would guess that most of their adjustments are just going to be vertical/speed changes so I would think this group of sixty will continue to spread out but remain in basically the same orbit. The next group will be spread out in a different orbit. And so on with subsequent groups. Maybe that will make things a bit easier for tracking. Although I’m not sure what happens over the long term.
I’m not sure why, but apparently they launched to a lower altitude than the operational 550 km. They’ll be using Hall effect thrusters to raise their orbits. At least that’s what several stories have reported.
But I didn’t mean to imply this was a difficult tracking problem. It’s just a different one. Software (and I’m sure the work is automated) tends to be best on the applications the programmers had in mind when they wrote it, and the test plans tend to focus on expected use. The fact that this is electric propulsion (constant, low thrust for long periods,) and sixty of them at once, is not what I suspect the programers were thinking of. I also suspect it would be easier if SpaceX provided the thrust profiles, and I wouldn’t be surprised if they were willing to do so. But that’s probably not in the software either. All that mostly likely means more work by hand and someone being tasked to write a new version of the software.
I think the idea was a lower orbit would mean a quicker re-entry if there were any failures. Also I would imagine they wanted to keep them under the ISS orbit until they were under their own power, another reason incidentally to raise the ISS orbit since it’s no longer restricted by the Shuttle’s performance limitations.
SpaceX has pretty close cooperation with Joint Space
Operations Center (JSpOC), they started simulation exercises with JSpOC for Starlink as early as 2017, so I think DoD should be well prepared for this.
Since Starlink will rely on the debris tracking information from JSpOC to perform automatic collision avoidance manuveurs, it is in SpaceX’s best interest to keep JSpOC running smoothly.
Not yet. I don’t think NORAD has determined their orbits yet. When they do they will release the 2 line orbital elements for each satellite. I have been waiting for these to put into my satellite tracking app so I will know when to look for them.
Try https://www.n2yo.com/passes… or https://www.satflare.com/tr…
Note they’re using unofficial TLE, so some errors in the prediction are to be expected.
I counted 50 just watching the video. I would like to know how bright they were.
Beautiful. Just imagine when the12,000 planned are in orbit. The sky will be full of satellites. I am thinking that with 12,000 satellites in 9 orbital planes that will be about 4 satellites per degree of orbit. That means there will be two or three satellite strings visible at a time during sunset and sunrise, a real sight to see.
Looks like they will be passing almost directly over the east coast tonight just after 10:00 pm which should provide good illumination. Binoculars recommended in order to make out individual satellites. Exact times can be determined for specific locations on the CalSKY website. Note that if not a subscriber you can only use their website for thirty minutes at a time so be sure to write down or copy/paste the results before you exit the site.
12,000 satellites will be quite a lot to launch with just Falcon 9 rockets. That would be 200 launches, at 60 per launch. That is almost 3 times as many launches as SpaceX has ever had. This makes me think SpaceX will want to use their Super Heavy instead, once that is available and viable. How many StarLink satellites would a Super Heavy realistically launch at a time? Whatever the number, that would be quite something to see deployed from the ground.
The Starship Chomper satellite deployer should carry a few hundred, ~1,000 m3 of cargo volume, they’ve said the v2.0 Starlinks will fly on it.
Jonathan McDowell, Harvard Smithsonian Center for Astrophysics
https://twitter.com/planet4…
https://twitter.com/planet4…
I just saw them fly over Atlanta. I live in a northeastern suburb and they went almost directly overhead at about 10:08 pm and based on the northeasterly trajectory they would have passed directly over Atlanta just before passing over me. Very faint, I wouldn’t have seen them except one of them flared for a moment to the brightness of a normal satellite which allowed me to get my binoculars on them. I would estimate that I saw about half of them, spread out over about three minutes. Many of them were travelling in clusters of two to four, others were single or at least that’s how they appeared. And they were not all in a straight line, definitely some lateral separation, which I’m pretty sure of because they were nearly directly overhead, each cluster had some lateral separation within it, and different clusters (or singles) were definitely not behind each other, although still within the same FOV of my binoculars.
And all the astronomers on Twitter are having kittens right now. I still can’t wrap my head around that yet. Iridium flares were a thing, so certainly the same thing could have been expected from Starlink satellites. So why are we just now hearing a public outcry from astronomers even though Starlink has been years in the making? I don’t get it. I’d like to see a well researched article about that issue.
There were a few complaints and comments to the FCC. But not many and not loud. I suspect people didn’t believe it. I mean, 12,000 satellites is about six times as many as all currently operational satellites. Remember people’s reaction to landing a first stage? Or reusing it? Actually, I remember a professor who does space physics for a living, who didn’t think the cost of a Falcon 9 or the idea of commercial cargo was credible, even after the first operational Dragon flight to ISS. I suspect most astronomers, if they heard about it, just said, “12,000 satellites? Yea, sure. I’ll believe it when I see it.”
I can understand that. This seems like a case of failure to understand advances and requirements coming from other fields creating system integration problems on a global scale.
Starlink,com is now online and Elon Musk is talking about being able to offer service after only 6 more launches. Given that he has stated before they hope to do 2-6 more Starlink launches this year he may be offering service well before any of his competitors even start deploying their constellations in orbit. The website is here.
http://www.starlink.com
That’s good, the sooner they can generate some revenue the better. Staying ahead of the creditors will likely be as big of a challenge as the technical ones as they expand the system.
Actually this went out today:
Dear Trustees,
As many of you are aware, Elon Musk’s company SpaceX has launched some satellites to provide Internet service from space to ground. They are quite visible and videos of their night time appearance have been widely disseminated on the Internet, with a wide range of responses.
Although much data still needs to be gathered about their impact on astronomical research from the ground and the general quality of the night sky for all, the Twitterverse is exploding right now on the matter and calls for prompt action are now descending on our leadership, our committees and the Executive Office.
At times like these, it is important to let folks know what we are doing and that we are taking a reasoned and informed approach to responding instead of responding quickly without complete information and understanding. This is why our positions are widely respected in the policy environment and our reputation as balanced and careful players in the policy space remains secure.
I am writing to let you know what the AAS is currently doing and will also share this information with our AAS Agents for broader dissemination.
First off, we have a committee of experts on Light Pollution, RFI and Space Debris and they’ve been tracking this since the beginning (and some before) and are formulating a position statement for the Board to consider. I’m not sure they will be done by the June meeting, but I believe they are working toward that goal…they’ve kept Megan informed as they’ve proceeded (and us here in the EO). They are planning to use the Starlink issue to speak more broadly about the impact of satellites on research and how negative impacts can be minimized along with other issues…but will not focus exclusively on the Starlink issue…far better to establish a significant marker using the notoriety of the current situation.
The CAPP has also been brought in on the issue and are talking up the matter via email. Their thinking will inform any statement and any action proposed for the AAS to take as well as subsequent policy activities.
AAS Deputy Executive Officer and Director for Public Policy, Joel Parriott has been actively tracking the issue and issued a tweet a few hours ago on the matter.
So, if you get any queries along the lines of ‘what is the AAS doing about this’, now you know.
Please refer any specific questions to Joel or myself. We will respond as best we are able given the rapid development of this matter and our other pending duties prior to the AAS meeting in St. Louis.
Best.
Kevin.
[Kevin B. Marvel, Executive Officer, American Astronomical Society]