As someone who co-incidentally started dabbling in Astrophotography as a hobby in early 2019 before Starlink launched, back then you literally could capture a single 20-second exposure (on a very wide lens, so no obvious star trail/blur at that focal length due to the Earth's rotation), and get images with no satellites.
Now (and even in 2021 it was getting hard to do that) it's impossible to do that, even with 10 second exposures.
What's needed now is multiple exposures, and merging/integrating them in something like Siril (https://siril.org/) to remove the obvious satellite trails.
However, arguably, integrating multiple exposures, while annoying and time-consuming workflow-wise (i.e. can't just look at images directly from camera, and currently need to convert to TIFF first) is often the better way to get slightly-less-noisy images anyway, and integrate effectively longer exposures without star-trails, so it's a tricky one.
genewitch · 11d ago
Auto stakkert
I think it runs off a .mov or other video file, you add black frames, etc.
ag56 · 10d ago
At no point does the article enlighten me of the actual ‘problem’. The photo is beautiful. The ability to even capture this signifies technological advancement, which I think wonderful.
In some way this reminds me of living in SF back in 2015, and all the arguments over the towers going up in soma. “No one wants the Manhattanization of the city” was accepted fact on both sides. Yet that wasn’t an obvious fact to me at all, and I could never find an argument in support of this ‘fact’.
Can someone enlighten me here?
starkrights · 9d ago
You acknowledge the existence of things blocking <something>, and can't imagine that there are people who want to see <something>?
I feel like when <something> is the sky, potential counterpoints can't be that far. For a direct response to your question: the sky and the stars beyond have been present and visible to every human, throughout all of history- how might different people feel about it becoming obstructed? Philosophically? Emotionally? Pragmatically?
The following types of people might feel strongly about this for some reason or another- I feel like steelmaning hypothetical opinions they might have is a really enriching thing to do.
- Photographers / enthusiasts
- Astronomers / enthusiasts
- Those who enjoy nature
I personally have a mixed opinion, probably leaning towards alignment with the above groups, but I can also steelman the thought processes of those who'd think this is cool or fascinating (because of course, it is!)
I'm not trying to convince you of something about the post subject here; The rhetorical questions above are not intended to be read as "how don't you understand this and agree with me", but instead "how/why did these potential viewpoints not find you?" The lack of mention of any other viewpoint comes off as almost poor-faith or naivete.
In the SWE community, people place a lot of emphasis on attempting to find solutions to a problem yourself first, before asking a question (and detailing what you've tried/explored already) to a community. With that mentality, it irks me when I see comments that don't seem to apply the same rigor to rhetorical discussions.
At the risk of being overtly snarky, could you really not conjure anyone that might have an opposing viewpoint?
starkrights · 9d ago
And fwiw, I also think the image is really cool. It's insane the world we've built, and imagining the context of all the math, physics, and human power of will that are behind those streaks of light is awesome.
But a negative viewpoint can't be that hard to see, right?
herewulf · 9d ago
> - Photographers / enthusiasts
Sorry, but the ship has sailed. Fix your problems in software maybe.
> - Astronomers / enthusiasts
Every Starship launch should offer ride-share for a space based observatory. Astronomy will only improve with space based telescopes. Yes, spacecraft are expensive but so are Earth based observatories, but how does it look with launch cost removed from the equation?
> - Those who enjoy nature
Generally can't see the satellites with the naked eye. Should probably concentrate on not walking into a hole / body of water / off a steep precipice.
This complaint about the aesthetics of the night sky is the wimpy enemy of progress. Imagine bronze / iron age people up in arms because suddenly the sea is full of fishing boats and merchant vessels. Or people up in arms because farmland has spoiled the view of forests.
Yes, I think this stuff looks nice without man-made things. I enjoy the night sky. I also enjoy being able to eat and utilize modern technology. There will come a day when spacecraft coming and going will be as routine as we see airplanes now, so our descendants will have that to complain about next, until it becomes as pointless to complain about as the asphalt roads that have lead to and from or houses.
Space based technology will make life better for all of humanity just like every technology that has come before it. The genie is out of the bottle and isn't going back in.
Miraste · 8d ago
>how does it look with launch cost removed from the equation?
The Webb Space Telescope cost $10 billion, and has a 6.5 meter mirror. With the launch cost removed, it cost $9.5 billion.
The Extremely Large Telescope is located on Earth, costs a little over $1 billion, and has a 39 meter mirror.
The idea of completely replacing ground observatories with orbital ones is so infeasible it's not really worth discussing. If satellite pollution grows so extreme they can no longer function, those capabilities will simply be lost.
asdefghyk · 10d ago
The article mentions the problem ....
"....Rozells’ composite visually echoes pleas from astronomers, who warn that although satellites collect essential data, the staggering amount filling our skies will only worsen light pollution and our ability to study what lies beyond. Because this industry has little regulation, the problem could go unchecked....."
CognitiveLens · 9d ago
I realize it's a nit-pick, but that is not at all the common definition of light pollution as it relates to night skies.
defrost · 9d ago
It falls under clause three:
What is light pollution
Light Pollution is the excess or inappropriate artificial light outdoors. Light pollution occurs in three ways: glare, light trespass, and skyglow.
\* Glare is the bright and uncomfortable light shining directly to the observer that interferes with your vision.
\* Light trespass is the unintended spill of artificial light into other people’s property or space and often becomes a source of conflict.
\* Skyglow is the brightening of the night sky from human-caused light scattered in the atmosphere.
Reflected sunlight from a human object spilling light into an environment that would otherwise not have that reflected sunlight is very much in the spirit of light pollution.
It's certainly seen as such by astronomers.
yencabulator · 8d ago
Skyglow is when you see the horizon light up in the direction of a city, not the light reflecting from a satellite. Look at the photo in your own link.
defrost · 8d ago
Let's assume I've read the link and have had discussions with both visual and radio spectrum astronomers and astrophysicists.
Starlink satellites pollute the night sky with both reflected sunlight and intended and unintended radio spectrum noise.
Manmade objects that inject light into an otherwise dark sky fit the category of skyglow, reflected sunlight tends to be sharper and less diffuse than atmospherically scattered ground lighting .. it's all extraneous human caused pollution from the PoV of telescopes.
SequoiaHope · 10d ago
I do find the juxtaposition of “look at this image of satellites” and “the image is a composition of 360 photographs” to require a certain leap of logic that hasn’t been established. On the one hand, it shows that a lot of satellites are visible throughout the night. On the other hand it’s harder to understand what the broader implications of this are.
spookie · 9d ago
imagine if one of those blows up.
Now imagine the probability of the debris hitting other satellites and causing even more debris.
Finally, compare how many satellites have been launched in the past 5 years versus the rest of history.
trebligdivad · 10d ago
The clear grid patterns are really fantastic.
(I realise that it's bad and all that - but still, those grids are amazing to see)
404mm · 10d ago
Had the same thought. In a way, that photo is absolutely stunning and beautiful in its own way. But I do understand how this is a huge problem for the astronomers.
jfengel · 11d ago
"Stitching together 343 distinct photos,"
I don't doubt that this is a real problem for astronomers and photographers, but I feel like if you had to work that hard, it doesn't really make your case.
darylteo · 10d ago
In his defense, he was shooting a star trail. @10s per exposure, 6 per minute, becomes 360 per hour.
I believe 30s might be more appropriate for star trails which makes satellite trails oh so much more obvious. But that means a 2-3 hour session of 2 exposures per minute.
I also used to take hundreds of photos in meteor season - and having to diff between meteors and satellites was quite time consuming.
dylan604 · 10d ago
in photos, meteors and satellites do not look the same. satellite trails are consistent lines. meteors start small, flare in the middle, and then ends small again. they are easy for humans to distinguish, so i'd assume some software could do it as well
threeseed · 11d ago
These photos are taken in pitch-black darkness.
You need to take a lot of exposures in order to get the data necessary to even see anything.
testing22321 · 10d ago
This is a single 10sec exposure in the Aussie outback on old consumer gear ( Sony a7iii )
You don’t need multiples, and you don’t need an overly long exposure.
genewitch · 10d ago
It sounds like you know what you're talking about until one realizes the earth is spinning. Wide field photos can be shot up to thirty seconds depending on the back and lens.
Anything more zoomy than 50mm uncropped you're getting streaks in < dozen seconds. There's a rule of thumb but I don't remember it.
Best course of action is to take a video and let a stacking program deal with it, especially if you use a real telescope.
Also the Sony a7r have like "150,000 ISO " and iirc cost like $3500 with a kit lens. That's a bit above consumer, but I may have mixed up models.
testing22321 · 10d ago
My camera is not an a7r. I paid $1200 for it used.
The exposure was 10 seconds, so by your own explanation, the spinning of the earth is not a problem ( as you can clearly see in the photo I linked )
teamonkey · 10d ago
An astronomy photo can commonly require hours or even tens of hours of exposure time.
testing22321 · 10d ago
The noise from a single image of that duration would be unworkable. Even if there were no planes or satellites, nobody would take that as a single exposure.
teamonkey · 10d ago
Signal scales with exposure time, noise scales with the root of exposure time. So although the noise increases with time, the signal-noise ratio increases faster. When dealing with astronomy photos, you want to maximise SNR.
(This is a simplification, there are many types of noise including shot noise and thermal noise, but in general this is the rule of thumb you use)
genewitch · 8d ago
your method of shooting the stars with a single long exposure is called a "wide-field" image. They're cool, but if you want to get any details of anything other than the milky way you either have to track or you have to stack. that's all there is to it.
I was going off memory, and with 50mm, it looks like 10 seconds is about when you start to get streaks, assuming no cropping. I have cropped sensors so even with a 10mm lens i can only do 12-15 seconds. I have a barn door tracker, and i know how to use https://www.autostakkert.com/
you need to have black frames for it to work, and ideally a lot of them (iirc at least a half dozen if not more) - because this is how the stacker knows which pixels are noisier than other ones, and also what the thermal noise of the sensor "looks like", at least the smarter stackers use it that way. you take a bunch of pictures with the lens cap on in a dark room at around the temperature you're gunna use it at.
real amateur astrophotography is done with CCD cameras, usually monochrome with filters (or a filter wheel), done in video mode, and the frames are processed after the fact. It takes hours with clear skies to make a decent deep field astrophotograph.
Rule of 500. Divide your lens focal length into 500. That's the longest exposure to avoid trails. 500 / 24mm = ~21s so your example would be 500 / 50mm = 10s.
No, you need to take a long exposure. Multiple exposures may improve the quality but isn’t necessary at all.
teamonkey · 10d ago
If the camera is stationary you must stack multiple short exposures to avoid star trails. You can only take long exposures with an equatorial mount.
littlestymaar · 10d ago
Not if your “long” exposure is just 10s long, which is enough to get those annoying starlink trails.
teamonkey · 10d ago
Sure, 10s is certainly long enough to capture Starlink trails, though 10s exposure is not especially long for an astro photo and you would typically want to take longer exposures or stack multiple shorter ones.
For example, my Seestar S50 takes many 10-second photos to form one exposure. I would normally expect to take 1500 10-second exposures or more for a good picture, perhaps over mutiple nights (although this is very different to a wide-field image like this). A Starlink trail would be very visible in any individual frame, often brighter than stars, and I would expect to capture many individual frames containing starlink trails.
t0bia_s · 9d ago
This is not true. Image in article is taken (and stack from many images) during sunset/sunrise when satellites are lighted by sun while photographer is in dark. It's not that visible at night.
nntwozz · 11d ago
You know those airplanes with a banner at the beach?
I can imagine a constellation of satellites writing ads (live) in space using mirrors and other nifty tech.
Unless regulation stops it.
blululu · 11d ago
There was a Russian start up planning to do this a few years back. They had actually reached a deal with Pepsi’s Russian operations until the public backlash convinced them to find a different public relations strategy.
https://phys.org/news/2019-01-astronomers-russian-billboards...
dreamcompiler · 11d ago
> Unless regulation stops it.
Or a ground-based megawatt IR laser with steerable optics.
fch42 · 10d ago
Somehow, this sounds quite appealing.
I'm waiting for the dystopian SciFi novel now where earth's last survivors blast the escape route through that cloud of satellite rubbish for their Starship (TM), by use of an array of those.
One can always dream.
ibizaman · 11d ago
That’s so true. I can see it too. The technology to make that must be super fun to work on but please I hope this will never happen. Can you imagine turning the whole sky as a giant pixelated screen to constantly show us ads? That’s as dystopian as it gets. Add to that the probable less than secure software to run it and hackers trying to show stuff up there. That’s something out of a Douglas Adams book. xD
Anyone attempting such a thing needs to be instantly put to death.
I’m fine with putting dots in the sky as a necessary side effect of providing some sort of useful service. Worldwide connectivity seems worth making astronomical observations a bit harder. But visual pollution for its own sake should be harshly discouraged.
jfengel · 11d ago
I don't think such a thing could hold together very long, unless it was just a string in a line. Maybe in Morse code?
With multiple launches you could probably get several parallel strings, and use it like a dot matrix printer. It would be a heck of a stunt. But I wouldn't expect it to last for more than one orbit, and only part of the planet could see it.
ordu · 10d ago
You can change brightness and color of individual satellites as they move, so they would match the "pixel" they are in now. Just imagine swarm of very small emitting light bugs moving chaotically behind your screen and changing colors as they move from one pixel to an other. The only issue is to make sure that at every moment each pixel has enough bugs to get the required brightness.
bethekidyouwant · 10d ago
Like regulation stopped trawling the ocean floor?
madmask · 11d ago
I wonder what uncontacted tribes think about starlink
mock-possum · 10d ago
If I hadn’t known what starlink was the first time I saw it, I would have assumed it was something artificial - the spacing and trajectory is far too regular to be a comet breaking up or something like that.
chii · 10d ago
well, if you could observe these things with the naked eye, they might imagine it's similar to a passing meteor.
teamonkey · 10d ago
You absolutely can see them with the naked eye. Very easy to spot on any given clear night if you know what to look for, especially when they’re moving in a cluster. They don’t look like meteors, far too slow.
madmask · 10d ago
I saw them myself with my naked eyes! They look like the iss
yellowapple · 10d ago
> Rozells’ composite visually echoes pleas from astronomers, who warn that although satellites collect essential data, the staggering amount filling our skies will only worsen light pollution and our ability to study what lies beyond. Because this industry has little regulation, the problem could go unchecked.
We have the technology to put observatories in orbit, where satellite "pollution", light pollution, atmospheric effects, etc. all become significantly less problematic. Maybe that should be our focus, rather than on shaming satellite constellations for doing essential work?
perilunar · 10d ago
I’d be more concerned about the light pollution from the city (Perth?) on the horizon.
bornfreddy · 10d ago
I'd be more concerned about both. One evil doesn't cancel the other.
perilunar · 9d ago
I'm not. I don't regard satellites as evil. While outside last night looking at the Milky Way I spotted 2 satellites and 3 aircraft. I like seeing the satellites; I dislike that I can't see the Milky Way at home in the city due to the light pollution.
ajxs · 10d ago
Would that be from Perth? Perth is around 180km away. Cervantes and Jurien Bay are nearby towns that could account for that light pollution.
littlestymaar · 10d ago
Whataboutism.
t0bia_s · 9d ago
Article with misleading conclusions.
Image is stacked from multiple images during sunset/sunrise when satellites are most visible because of sun position to observer. Photographer is in dark while satellites are lighted by direct sunlight.
Can't tell if you're joking or not, but SpaceX has indeed been collaborating with astronomical observatories to reduce the apparent magnitude (brightness) to ground for Starlink satellites. It's not as if the potential issues weren't apparent and reported on pretty early on, ie, [0] in summer 2020 before the network entered beta. It's not perfect and the period during orbit raising before the satellites enter operational orbits is more challenging, but very significant reductions have been achieved per recs, see for example "Starlink Gen 2 Mini Satellites Photometric Characterization" [1] in 2023 and "The Brightness of Starlink Mini Satellites During Orbit-Raising" [2] in 2024:
>When magnitudes are adjusted to a uniform distance of 1000 km the
means are 4.58 and 7.52, respectively. The difference of 2.94 between
distance-adjusted magnitudes above and below threshold implies that mitigation is
93% effective in reducing the brightness of orbit-raising spacecraft.
So there has been progress, though more may be possible particularly as Starship gives them more mass to work with for less money. That may bring new possibilities to spend mass on "cosmetic" purposes to shade and further reduce magnitude even if it contributes nothing to the core functionality. Same as more mass may allow regulators to feasibly require higher levels of redundancy and more margin for deorbiting in case of issues or at EOL.
Of course, that does leave older unmitigated working sats contributing to light pollution for the rest of their operational lifetimes, though worth noting that one of many major advantages for low-LEO/VLEO operation is that by design such lifetimes are much shorter, and in turn generation refresh will happen more quickly. Perhaps more importantly long term, there aren't as far as I know any actual international standards and agreements towards responsible brightness mitigation (or other issues like disposing of expended upper stages responsibly, standardized end-of-life deorbiting, etc). SpaceX has, for both PR and simple corporate self-interest reasons, been a pretty good actor so far even if they get a lot of attention for being the leading first mega constellation. But I really hope follow on efforts from other players can hit the ground running with magnitude reductions at least as good, and that SpaceX itself continues to improve (or at a bare minimum not backslide).
High bandwidth fully global comms is simply too valuable a capability to really imagine going back at this point. But that's no reason not to pursue reasonable compromise mitigations, and potentially some sort of funds to ultimately create far more orbital telescopes as well as part of the package taking full advantage of what upcoming cheap megalift will make possible.
It's not just optical pollution, the same satellites visible in the article photo over the Pinnacles are leaking radio spectrum noise into the ostensibly "Radio Quiet Zone" of the nearby Murchison that's home to cosmic microwave sensors and one regional part of the developing global SKA radio telescope platform.
genewitch · 10d ago
This would be real simple to prove, Starlink Satelites downlink on the same band as Satelite TV so you can use the receiver from a dish that downconverts it to something a cheap dongle can handle and put that all inside a grounded, metal box in the bed of a diesel and just record spectrum.
I was under the impression that actual space business people had ways of not leaking RF when flying over.
defrost · 10d ago
It's been proven by several teams already, eg:
In new research accepted for publication in Astronomy and Astrophysics Letters, we discovered Starlink satellites are also “leaking” radio signals that interfere with radio astronomy. Even in a “radio quiet zone” in outback Western Australia, we found the satellite emissions were far brighter than any natural source in the sky.
referencing: Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog (Sep. 2023)
It's an ongoing issue in that Starlink v1.0 leaked and as I recall promises were made that the next generation of satellites would leak less and turn off when over radio quiet zones .. that second gen group have (IIRC) more noise and continuing transmitting over RQZ's.
genewitch · 7d ago
> Although this IEMR abides by ITU-R guidelines, these intensities are large compared to the strongest astronomical radio sources in the sky and will therefore have the potential to disrupt astronomical observations at SKA-Low frequencies;
Sounds like the ITU-R messed up, regardless of why. starlink is 28% of the EIRP the ITU specified. And the "newer generation are a factor of 12 fainter".
We're talking micro. watts. of Effective Isotropic Radiating Power. with 0dBi antennas (unity gain).
I don't understand why they're using those oddball frequencies, but i haven't paid attention to band allocations in a long time. 159.4MHz is Land Mobile band plan - "business band 2 meters", and oh, 137.5 is "SPACE OPERATIONS". I almost want to guess that the 159.4 is a spur of something down around 39.9MHz, fourth harmonic or something. I don't see anything that would let starlink radiate there, unless they change frequencies over countries. Furthermore, it doesn't seem like the 159.4MHz signals will be a detriment to the facility in question, but merely possibly impinge on radio-astronomers.
I understand that these arrays are so sensitive that the RF they collect and process in the career of a scientist there is roughly equal to a cricket chirping once. or something. But microwatts are real tiny, too. Should be possible to put a notch filter at 137.5, or request space businesspeople to do intra-satellite on some other frequency.|
in fact, business idea: aim a yagi array where the satellites are as they pass over, can be done programmatically, or reactively - at least 4 sensors however far from the facility monitor the starlink downlink frequencies (not 137.5 and 159.4, but the ku band ones) - and then aim at the satellite.
I'll build it out with crap i have in my shed to prove it works if anyone is interested. If you know a satellite is in your second of sky, and you monitor, specifically, the 137.5 frequency with a separate, real sensitive antenna array, you can just drop the IQ/whatever from the radios for that timeframe.
This isn't rocket science, QRM and QRN will plague us forever. Thanks, Marconi.
WalterBright · 11d ago
> Can't tell if you're joking or not
Not. Often obvious simple solutions are overlooked. For example, NASA spent huge sums of money trying to design a gas gauge that will work in weightless conditions. Until an engineer suggested just having a "reserve" tank that has enough to bring the spacecraft out of orbit.
Another one was NASA spend a lot of money trying to figure out how to not have the Apollo capsule overheat from the sun. The trivial solution was to make it a rotisserie, i.e. slowly rotate it.
xoa · 11d ago
>Not. Often obvious simple solutions are overlooked.
I'm not sure I'd say "often" has something like what you offered up been overlooked by SpaceX. We're long, long past the early eras when everything was first getting figured out, and the timescales and costs are totally different. Talking of "obvious", painting something black in orbit has clear enormous thermal implications, and there are aspects of the system that seem necessarily reflective as well (solar panels, optical links and so on) and in turn mitigation requires cascading design decisions. These aren't platinum plated Apollo era programs either. Like, gut check here: do you see ANY space stations or satellites in space, at all, where they "just painted them black"? I don't think it's actually trivial at all.
Anyway main point is yes, it's recognized and yes, it's getting worked on (successfully!), and I hope that will ultimately help pave the road for any other future megaconstellation efforts by showing what's possible.
WalterBright · 10d ago
I've been designing things my entire professional life, and yes, engineers overlook the obvious all the time (me too!).
I always look for simpler ways, and often enough find them.
mmooss · 10d ago
That would seem to remediate one problem, but they still block the view of cameras and telescopes - worse, in a way, that they might block the view without the viewer realizing they missed the occulded star.
Might then have a lot of overheating satellites :)
WalterBright · 10d ago
Put the black surface an inch away from the satellite, supported by standoffs. That'll keep the heat away from the satellite.
Also, the black surface only needs to be on the Earth facing side.
goku12 · 10d ago
It isn't that simple, is it? Even if you place the black surface on a spacer (adding mass, might I add), the black surface itself is going to radiate heat back onto the satellite via blackbody radiation. This is always going to create a worse thermal situation unless you can somehow radiate away as much heat as you could with reflections. To see what I mean, check out JWST's thermal shield.
tzs · 10d ago
How about something like this?
| __
| |_/\_| |
| | \/ |__|
E 1 2 3
E is the Earth. 1 is a thin lightweight black disc to block the view of the rest of the satellite. 3 is the working parts of the satellite. 2 are mirrors to direct any emissions from 1 in the direction of 3 out to the sides and to direct any emissions from 3 in the direction of 1 out to sides.
goku12 · 9d ago
You should check the JWST thermal shield. It addresses exactly this problem. Also keep in mind the additional cost it incurs.
WalterBright · 10d ago
Consider a shaped charge. It seems wild to me that you can direct an explosion with various shapes of the explosive. Perhaps a similar idea can apply to the blackbody radiation - get it to radiate mostly away from the satellite.
Also, the black part will be pointed at the Earth, not the Sun.
perihelions · 10d ago
Not sure what geometry you're thinking of. Whatever idea it is, you're stuck dealing with Kirchoff's law, which says optical emissivity and absorptivity are the same number at any given wavelength. I.e., you can't create "one-way trap doors" for heat flow—that would be a Maxwell's demon. Stacking multiple surfaces isn't a way to circumvent this.
If it's just an asymmetric shape, with different material surfaces pointed in different directions, than that of course is permitted.
Kirchoff's law doesn't say which direction it emits in. As shaped charges can alter the direction of where the blast wave goes, I suspect an analogous behavior of a heat shield can direct where the emissions go. I.e. as you say, an asymmetric shape.
PS I haven't done thermo in nearly 50 years!
perihelions · 10d ago
V-groove radiators are a really neat, unintuitive design, which gets strong directionality out of thermal radiation. It's the thermal design SPHEREX went with—the space telescope that went up a few weeks ago, that was all over HN.
That's: a cavity that's a thin wedge in between two slightly angled plates, where the interior surface coating is partly emissive, and partly infrared-reflective—it can reflect the thermal radiation it emits. That means specular reflections, following geometric optics, so it works like a horn for light—beams it out the sides in a narrow cone.
To complicate it further I thought that some of the military sats had rotating black panels to shield them from ground visibility?
goku12 · 9d ago
It's likely that military satellites used a bunch of tricks to hide itself. But I don't know how useful they are these days. All major space powers have radars powerful enough to easily pick them out. They're needed for satellite collision avoidance analysis.
sandspar · 10d ago
You have to crack a few eggs to make an omelette. The benefits of satellites seem worth the cost, at least in the foreseeable future.
mmooss · 10d ago
That phrase is not seen as the opposite of wisdom. It is just an excuse to disregard costs and other responsibilities for your own benefit.
sandspar · 9d ago
Your statement doesn't make sense.
macinjosh · 11d ago
It is so polluted you need professional camera gear and processing of hundreds of photos together in order to show it. Get real. Internet access for poor, remote rural areas across the global is more important than convenient timelapse photography.
threeseed · 11d ago
a) You can take these photos with a smart phone.
b) In Australia we are rolling out fibre to rural areas and are testing 10Gb plans. Starlink will never come close to those speeds.
bigfatkitten · 9d ago
And you can see them with the naked eye. You don't even need to go anywhere terribly remote; there's sufficient darkness a 20 minute drive south of Canberra (population ~470,000, for those not familiar.)
throwaway2037 · 7d ago
I thought that the Australia National Broadband Network mostly services rural areas with microwave dishes (shortwave radio)? Are they changing their strategy? The original point of microwaves was to reduce cost of laying (fibre) cable. I tried to Google for any recent news about this roll-out that you speak of. Do you have a link that you can share?
saddat · 10d ago
Starling et al are about profit, ignoring their impact to humanity
Panzer04 · 10d ago
And they profit because people need the valuable service they provide.
I doubt astronomy is as important as providing good internet access to millions of people in low-service areas around the globe.
blitzar · 10d ago
Poor, remote rural people need influencers to tell them which lambo to buy too.
ezconnect · 11d ago
The poor can't afford it. Military use is the only way Starlink will stay afloat.
testing22321 · 10d ago
You are so far from the mark out is staggering. Starlink is priced differently in different countries, and is wildly popular in developing and undeveloped countries.
kofianon · 11d ago
A startup idea: launch satellites to capture clean night sky photos, with tiered subscription model of course.
kibwen · 11d ago
Startup idea: launch anti-satellite satellites to de-orbit other satellites littering your airspace.
pdw · 11d ago
The Kessler syndrome will take care of it
amelius · 10d ago
Ok, so just launch junk into space and wait.
goku12 · 10d ago
There's no concept of airspace in space. You have very few avenues to keep a sat restricted to a geographic region. Orbits like geostationary and molniya exist - but they come with their own limitations for many applications.
littlestymaar · 10d ago
The concept of “airspace” is purely a legal one and exits only if your country has an air force able to enforce it (see how Israel has absolute control over Lebanese airspace), any country with anti-sattelite technology could at its disposal could declare that their airspace goes up to the geostationary orbit or even above.
Of course it would complicate the use of satellites a lot, but given their military importance it's likely that this will happen at some point when the tech is ready (by tech I mean a way to stop foreign satellites from operating without causing Kessler syndrome)
goku12 · 9d ago
There are soft kill mechanisms that can avoid the Kessler syndrome, at least in the beginning. But that isn't the reason why territories aren't defined beyond the atmosphere. It's easy for a plane to avoid flying over another country. But it isn't as simple for satellites to avoid flying over another nation. Orbital mechanics doesn't give you much freedom to do that. Satellites overfly hostile territories thousands of times on a daily basis. If even the countries with soft kill ASAT starts prohibiting that, then spaceflight will become untenable in less than a day. The lack of territorial claims in space is just the world nations being reasonable.
littlestymaar · 9d ago
If you rely on nations being reasonable, prepare to be disappointed on a regular basis…
luqtas · 11d ago
HN Startup idea: train a gen. AI on NASA photos and sell custom photos /s
Now (and even in 2021 it was getting hard to do that) it's impossible to do that, even with 10 second exposures.
What's needed now is multiple exposures, and merging/integrating them in something like Siril (https://siril.org/) to remove the obvious satellite trails.
However, arguably, integrating multiple exposures, while annoying and time-consuming workflow-wise (i.e. can't just look at images directly from camera, and currently need to convert to TIFF first) is often the better way to get slightly-less-noisy images anyway, and integrate effectively longer exposures without star-trails, so it's a tricky one.
I think it runs off a .mov or other video file, you add black frames, etc.
In some way this reminds me of living in SF back in 2015, and all the arguments over the towers going up in soma. “No one wants the Manhattanization of the city” was accepted fact on both sides. Yet that wasn’t an obvious fact to me at all, and I could never find an argument in support of this ‘fact’.
Can someone enlighten me here?
I feel like when <something> is the sky, potential counterpoints can't be that far. For a direct response to your question: the sky and the stars beyond have been present and visible to every human, throughout all of history- how might different people feel about it becoming obstructed? Philosophically? Emotionally? Pragmatically?
The following types of people might feel strongly about this for some reason or another- I feel like steelmaning hypothetical opinions they might have is a really enriching thing to do.
- Photographers / enthusiasts
- Astronomers / enthusiasts
- Those who enjoy nature
I personally have a mixed opinion, probably leaning towards alignment with the above groups, but I can also steelman the thought processes of those who'd think this is cool or fascinating (because of course, it is!)
I'm not trying to convince you of something about the post subject here; The rhetorical questions above are not intended to be read as "how don't you understand this and agree with me", but instead "how/why did these potential viewpoints not find you?" The lack of mention of any other viewpoint comes off as almost poor-faith or naivete.
In the SWE community, people place a lot of emphasis on attempting to find solutions to a problem yourself first, before asking a question (and detailing what you've tried/explored already) to a community. With that mentality, it irks me when I see comments that don't seem to apply the same rigor to rhetorical discussions.
At the risk of being overtly snarky, could you really not conjure anyone that might have an opposing viewpoint?
But a negative viewpoint can't be that hard to see, right?
Sorry, but the ship has sailed. Fix your problems in software maybe.
> - Astronomers / enthusiasts
Every Starship launch should offer ride-share for a space based observatory. Astronomy will only improve with space based telescopes. Yes, spacecraft are expensive but so are Earth based observatories, but how does it look with launch cost removed from the equation?
> - Those who enjoy nature
Generally can't see the satellites with the naked eye. Should probably concentrate on not walking into a hole / body of water / off a steep precipice.
This complaint about the aesthetics of the night sky is the wimpy enemy of progress. Imagine bronze / iron age people up in arms because suddenly the sea is full of fishing boats and merchant vessels. Or people up in arms because farmland has spoiled the view of forests.
Yes, I think this stuff looks nice without man-made things. I enjoy the night sky. I also enjoy being able to eat and utilize modern technology. There will come a day when spacecraft coming and going will be as routine as we see airplanes now, so our descendants will have that to complain about next, until it becomes as pointless to complain about as the asphalt roads that have lead to and from or houses.
Space based technology will make life better for all of humanity just like every technology that has come before it. The genie is out of the bottle and isn't going back in.
The Webb Space Telescope cost $10 billion, and has a 6.5 meter mirror. With the launch cost removed, it cost $9.5 billion.
The Extremely Large Telescope is located on Earth, costs a little over $1 billion, and has a 39 meter mirror.
The idea of completely replacing ground observatories with orbital ones is so infeasible it's not really worth discussing. If satellite pollution grows so extreme they can no longer function, those capabilities will simply be lost.
"....Rozells’ composite visually echoes pleas from astronomers, who warn that although satellites collect essential data, the staggering amount filling our skies will only worsen light pollution and our ability to study what lies beyond. Because this industry has little regulation, the problem could go unchecked....."
Reflected sunlight from a human object spilling light into an environment that would otherwise not have that reflected sunlight is very much in the spirit of light pollution.
It's certainly seen as such by astronomers.
Starlink satellites pollute the night sky with both reflected sunlight and intended and unintended radio spectrum noise.
Manmade objects that inject light into an otherwise dark sky fit the category of skyglow, reflected sunlight tends to be sharper and less diffuse than atmospherically scattered ground lighting .. it's all extraneous human caused pollution from the PoV of telescopes.
Now imagine the probability of the debris hitting other satellites and causing even more debris.
Finally, compare how many satellites have been launched in the past 5 years versus the rest of history.
I don't doubt that this is a real problem for astronomers and photographers, but I feel like if you had to work that hard, it doesn't really make your case.
I believe 30s might be more appropriate for star trails which makes satellite trails oh so much more obvious. But that means a 2-3 hour session of 2 exposures per minute.
I also used to take hundreds of photos in meteor season - and having to diff between meteors and satellites was quite time consuming.
You need to take a lot of exposures in order to get the data necessary to even see anything.
https://www.instagram.com/p/CersLuLBfCz
You don’t need multiples, and you don’t need an overly long exposure.
Anything more zoomy than 50mm uncropped you're getting streaks in < dozen seconds. There's a rule of thumb but I don't remember it.
Best course of action is to take a video and let a stacking program deal with it, especially if you use a real telescope.
Also the Sony a7r have like "150,000 ISO " and iirc cost like $3500 with a kit lens. That's a bit above consumer, but I may have mixed up models.
The exposure was 10 seconds, so by your own explanation, the spinning of the earth is not a problem ( as you can clearly see in the photo I linked )
(This is a simplification, there are many types of noise including shot noise and thermal noise, but in general this is the rule of thumb you use)
I was going off memory, and with 50mm, it looks like 10 seconds is about when you start to get streaks, assuming no cropping. I have cropped sensors so even with a 10mm lens i can only do 12-15 seconds. I have a barn door tracker, and i know how to use https://www.autostakkert.com/
you need to have black frames for it to work, and ideally a lot of them (iirc at least a half dozen if not more) - because this is how the stacker knows which pixels are noisier than other ones, and also what the thermal noise of the sensor "looks like", at least the smarter stackers use it that way. you take a bunch of pictures with the lens cap on in a dark room at around the temperature you're gunna use it at.
real amateur astrophotography is done with CCD cameras, usually monochrome with filters (or a filter wheel), done in video mode, and the frames are processed after the fact. It takes hours with clear skies to make a decent deep field astrophotograph.
Some random search result:
https://astrobackyard.com/the-500-rule/
For example, my Seestar S50 takes many 10-second photos to form one exposure. I would normally expect to take 1500 10-second exposures or more for a good picture, perhaps over mutiple nights (although this is very different to a wide-field image like this). A Starlink trail would be very visible in any individual frame, often brighter than stars, and I would expect to capture many individual frames containing starlink trails.
I can imagine a constellation of satellites writing ads (live) in space using mirrors and other nifty tech.
Unless regulation stops it.
Or a ground-based megawatt IR laser with steerable optics.
I'm waiting for the dystopian SciFi novel now where earth's last survivors blast the escape route through that cloud of satellite rubbish for their Starship (TM), by use of an array of those.
One can always dream.
I’m fine with putting dots in the sky as a necessary side effect of providing some sort of useful service. Worldwide connectivity seems worth making astronomical observations a bit harder. But visual pollution for its own sake should be harshly discouraged.
With multiple launches you could probably get several parallel strings, and use it like a dot matrix printer. It would be a heck of a stunt. But I wouldn't expect it to last for more than one orbit, and only part of the planet could see it.
We have the technology to put observatories in orbit, where satellite "pollution", light pollution, atmospheric effects, etc. all become significantly less problematic. Maybe that should be our focus, rather than on shaming satellite constellations for doing essential work?
Image is stacked from multiple images during sunset/sunrise when satellites are most visible because of sun position to observer. Photographer is in dark while satellites are lighted by direct sunlight.
During night, its barely visible.
>When magnitudes are adjusted to a uniform distance of 1000 km the means are 4.58 and 7.52, respectively. The difference of 2.94 between distance-adjusted magnitudes above and below threshold implies that mitigation is 93% effective in reducing the brightness of orbit-raising spacecraft.
So there has been progress, though more may be possible particularly as Starship gives them more mass to work with for less money. That may bring new possibilities to spend mass on "cosmetic" purposes to shade and further reduce magnitude even if it contributes nothing to the core functionality. Same as more mass may allow regulators to feasibly require higher levels of redundancy and more margin for deorbiting in case of issues or at EOL.
Of course, that does leave older unmitigated working sats contributing to light pollution for the rest of their operational lifetimes, though worth noting that one of many major advantages for low-LEO/VLEO operation is that by design such lifetimes are much shorter, and in turn generation refresh will happen more quickly. Perhaps more importantly long term, there aren't as far as I know any actual international standards and agreements towards responsible brightness mitigation (or other issues like disposing of expended upper stages responsibly, standardized end-of-life deorbiting, etc). SpaceX has, for both PR and simple corporate self-interest reasons, been a pretty good actor so far even if they get a lot of attention for being the leading first mega constellation. But I really hope follow on efforts from other players can hit the ground running with magnitude reductions at least as good, and that SpaceX itself continues to improve (or at a bare minimum not backslide).
High bandwidth fully global comms is simply too valuable a capability to really imagine going back at this point. But that's no reason not to pursue reasonable compromise mitigations, and potentially some sort of funds to ultimately create far more orbital telescopes as well as part of the package taking full advantage of what upcoming cheap megalift will make possible.
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0: "Impact of Satellite Constellations on Optical Astronomy and Recommendations Toward Mitigations" | https://aas.org/sites/default/files/2020-08/SATCON1-Report.p...
1: https://arxiv.org/pdf/2306.06657
2: https://arxiv.org/pdf/2405.12007
I was under the impression that actual space business people had ways of not leaking RF when flying over.
referencing: Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog (Sep. 2023)
https://arxiv.org/abs/2309.15672
It's an ongoing issue in that Starlink v1.0 leaked and as I recall promises were made that the next generation of satellites would leak less and turn off when over radio quiet zones .. that second gen group have (IIRC) more noise and continuing transmitting over RQZ's.
Sounds like the ITU-R messed up, regardless of why. starlink is 28% of the EIRP the ITU specified. And the "newer generation are a factor of 12 fainter".
We're talking micro. watts. of Effective Isotropic Radiating Power. with 0dBi antennas (unity gain).
I don't understand why they're using those oddball frequencies, but i haven't paid attention to band allocations in a long time. 159.4MHz is Land Mobile band plan - "business band 2 meters", and oh, 137.5 is "SPACE OPERATIONS". I almost want to guess that the 159.4 is a spur of something down around 39.9MHz, fourth harmonic or something. I don't see anything that would let starlink radiate there, unless they change frequencies over countries. Furthermore, it doesn't seem like the 159.4MHz signals will be a detriment to the facility in question, but merely possibly impinge on radio-astronomers.
I understand that these arrays are so sensitive that the RF they collect and process in the career of a scientist there is roughly equal to a cricket chirping once. or something. But microwatts are real tiny, too. Should be possible to put a notch filter at 137.5, or request space businesspeople to do intra-satellite on some other frequency.|
in fact, business idea: aim a yagi array where the satellites are as they pass over, can be done programmatically, or reactively - at least 4 sensors however far from the facility monitor the starlink downlink frequencies (not 137.5 and 159.4, but the ku band ones) - and then aim at the satellite.
I'll build it out with crap i have in my shed to prove it works if anyone is interested. If you know a satellite is in your second of sky, and you monitor, specifically, the 137.5 frequency with a separate, real sensitive antenna array, you can just drop the IQ/whatever from the radios for that timeframe.
This isn't rocket science, QRM and QRN will plague us forever. Thanks, Marconi.
Not. Often obvious simple solutions are overlooked. For example, NASA spent huge sums of money trying to design a gas gauge that will work in weightless conditions. Until an engineer suggested just having a "reserve" tank that has enough to bring the spacecraft out of orbit.
Another one was NASA spend a lot of money trying to figure out how to not have the Apollo capsule overheat from the sun. The trivial solution was to make it a rotisserie, i.e. slowly rotate it.
I'm not sure I'd say "often" has something like what you offered up been overlooked by SpaceX. We're long, long past the early eras when everything was first getting figured out, and the timescales and costs are totally different. Talking of "obvious", painting something black in orbit has clear enormous thermal implications, and there are aspects of the system that seem necessarily reflective as well (solar panels, optical links and so on) and in turn mitigation requires cascading design decisions. These aren't platinum plated Apollo era programs either. Like, gut check here: do you see ANY space stations or satellites in space, at all, where they "just painted them black"? I don't think it's actually trivial at all.
Anyway main point is yes, it's recognized and yes, it's getting worked on (successfully!), and I hope that will ultimately help pave the road for any other future megaconstellation efforts by showing what's possible.
I always look for simpler ways, and often enough find them.
https://en.wikipedia.org/wiki/Vantablack
<https://www.colorado.edu/faculty/kantha/sites/default/files/...>
(A plot point in Neal Stephenson's Seveneves.)
https://science.nasa.gov/solar-system/meteors-meteorites/fac...
Also, the black surface only needs to be on the Earth facing side.
Also, the black part will be pointed at the Earth, not the Sun.
If it's just an asymmetric shape, with different material surfaces pointed in different directions, than that of course is permitted.
https://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_r...
PS I haven't done thermo in nearly 50 years!
That's: a cavity that's a thin wedge in between two slightly angled plates, where the interior surface coating is partly emissive, and partly infrared-reflective—it can reflect the thermal radiation it emits. That means specular reflections, following geometric optics, so it works like a horn for light—beams it out the sides in a narrow cone.
(.pdf) https://ttu-ir.tdl.org/server/api/core/bitstreams/71aee1e9-3...
b) In Australia we are rolling out fibre to rural areas and are testing 10Gb plans. Starlink will never come close to those speeds.
I doubt astronomy is as important as providing good internet access to millions of people in low-service areas around the globe.
Of course it would complicate the use of satellites a lot, but given their military importance it's likely that this will happen at some point when the tech is ready (by tech I mean a way to stop foreign satellites from operating without causing Kessler syndrome)