There certainly is a real concern for astronomers, but the photo illustrations used in the article are selected to make things seem worse than they really are. They're wide field of view, long-duration exposures. That used to be the way astronomers imaged space, with film systems a century ago. But these days astronomical telescopes tend to have much narrower fields of view (like tiny soda straws peering into one particular spot in space) and use image stacking, a technique where many individual images are processed to form the final image (very simplistic overview: https://www.skyatnightmagazine.com/astrophotography/astropho... .) Using image stacking and armed with accurate catalogs that predict precisely where every satellite will be at any time, enables the removal of satellites during the image stacking process. Or they can just use that information for better scheduling: wait a minute or two to image a particular spot, so there won't be satellites in the field of view.
The article definitely gets this part right:
> “Some astronomers see this as a true ‘hair on fire’ emergency, heralding irretrievable losses to space science; others present a more sanguine face, depicting this as yet another challenge to be surmounted in surveying a decreasingly pristine sky,” Koplow remarks.
Being involved in both space and astronomy plants me squarely in the latter camp. It takes a bit more work and software, but having so many satellites in space is a surmountable challenge for terrestrial astronomers. (Not to mention, these days some of the best astronomy is performed by telescopes in space, so astronomy overall benefits by having easier access to space.)
If you are looking for short period events, losing a single frame can mean losing critical data.
> Or they can just use that information for better scheduling: wait a minute or two to image a particular spot, so there won't be satellites in the field of view.
Which means more time and effort, and ultimately money needs to be spent on scheduling observations to avoid the thousands of these satellites.
And sometimes it isn't an option. What if a GRB happens in the same field of view as one of these satellites and you want to observe it as soon as possible?
Now there are some types of observations that won't be impacted that much. If you can tolerate scheduling around it, or throwing away some of your frames it is just a minor annoyance. But a lot of observations are also more sensitive to such disruptions.
Yeah, what if? I mean, you probably missed the GRB, sure, but apart from that, you'll be fine and you can wait for the next one, or find a data from somewhere else.
> They're wide field of view, long-duration exposures. That used to be the way astronomers imaged space,
Sorry, but one of the two example images (https://noirlab.edu/public/images/iotw1946a/) is a single 333-second exposure with a modern survey camera, the Dark Energy Camera. This is not particularly long nor does it represent some outmoded observational strategy. Large, wide-field imaging sky surveys (such as the upcoming Rubin Observatory) are among the highest-profile ground-based astronomy projects today.
Masking and stacking can mitigate the problem but it does not of course compensate for the lost area and sensitivity. And the brightest satellites (like BlueWalker) saturate the readout electronics and spoil the whole exposure.
Narrow field instruments (such as spectrographs) have less geometric chance of seeing a satellite but tend to take longer exposures (tens of minutes), so there is a greater loss of telescope time when a streak does happen.
Where do you see that the full well of those CCDs are fully saturated by a single satellite streak?
Even if that was the case, that seems a very poor design for a sensor and not really an issue of satellites. If a satellite streak can saturate your well, then so could a decently dense star field.
Do they blow out the individual pixels? Sure. But you just stack.
You don't lose sensitivity just because your stack rejected pixels, that's not how stacking works. You wind up with a tiny bit more noise, how much more depends on your capture. But not lower sensitivity, stacking isn't just average an area
It's not really that it saturates the entire image, it's that bright objects creates non-linear and ghosting artifacts which degrade the sensitivity of the entire exposure, even after post-processing in software.
Thanks for providing all those links. Indeed, the key there is peak magnitude. BlueWalker 3 has a giant array that reflects light like a mirror. So when you happen to get the angle of incidence exactly equal to the angle of reflection, it shines quite brightly. Of course since it's reflecting all sunlight in one direction, that means from all other spots on earth it will be extremely dim.
Also note that BlueWalker 3, like most low-earth orbit satellites, is only visible during "terminator conditions", when the satellite itself is illuminated by the sun but the telescope is still in darkness. Those times are typically an hour or so after sundown or an hour or so before sunrise. So one solution is to schedule astronomy for the middle of the night, when none of these low earth satellites will lit by the sun at all. Which certainly increases the costs of astronomy, since you can't use your telescope for as many hours per day.
Or, just use your space object catalog to look elsewhere in the sky when bright satellites happen to be in the sky during terminator illumination conditions. Which I see is one of the things your last link, "Mitigation of LEO Satellite Brightness and Trail Effects on the Rubin Observatory LSST", suggests!
SpaceX has offered their space-rated mirror technology at cost to other satellite manufacturers, but it seems AST SpaceMobile hasn't taken them up on the offer. I can't see any mirrored surfaces on BlueWalker 3.
>that means from all other spots on earth it will be extremely dim
The second paper I linked (see Figure 1) shows a minimum magnitude after array deployment of 5.5 magnitude, from multiple observatories at multiple locations on the Earth. That's still 10 times brighter than the IAU limit.
>just look elsewhere in the sky
The hottest thing right now is whole-sky surveys like Vera Rubin (which are important because they can alert other telescopes to transient events), which can't really do that because they're already looking at... the whole sky.
Not really. Astronomical dusk and dawn are different than civil dusk or dawn, you'd normally skip an hour or so after sunset and before sunrise anyway.
> Masking and stacking can mitigate the problem but it does not of course compensate for the lost area and sensitivity. And the brightest satellites (like BlueWalker) saturate the readout electronics and spoil the whole exposure.
Is this only a problem in systems that aren't aware of where the satellites will be? I naively assume that, if the system knew, it could start exposing in the next clear window. I naively assume that the window is almost always clear, especially for an individual sensor.
Even if they don’t know where the satellites will be, a simple motion detection algorithm in the stacker would delete the streak caused by the satellite. A given pixel will only be impacted for a few exposures, so just grab 5% more images.
I’d guess terrestrial light pollution is a much bigger problem.
You say it like major observatory telescopes are sitting idle, but they're not. In practice what actually happens is you lose 5% of your scientific data return.
>terrestrial light pollution
Problem is that it's global vs local, so our normal solution for terrestrial light pollution (build telescopes in a remotely populated area) doesn't work.
If it's just a matter of 5% inefficiency, I have to think that there must exist some possible mechanism for capturing the economic benefits of satellite internet (with a tax, perhaps) and redirecting a portion to astronomy to increase budgets there by 5% (or more) so that everybody wins.
Budgets are fixed, so again this also boils down to "just do 5% less science."
Believe it or not, actually using 100% capacity on the big expensive telescope you paid for isn't some brilliant unheard-of suggestion like people seem to think. This Dunning-Kruger idea always seems to crop up whenever this particular topic is in the news.
There simply isn't any "slop in the system" that lets you get that 5% (and climbing!) back "for free." If there was, then that inefficiency should be fixed regardless of the situation with megaconstellations.
Doing 5% less science is an acceptable cost for full commercial space exploitation. I'd rather have internet service in 100% of the US than an extra few graduate theses.
And who knows, necessity is the mother of invention so one of those grad students could invent a way around it.
That's certainly one choice we can make as a society.
However my point is we shouldn't delude ourselves that there's some "easy" fix, therefore the cost should actually by counted as zero. This defense mechanism is misguided and uninformed, yet it's shockingly common to have it (or some variation) crop up when discussing this particular topic.
Personally, I blame the current tribalize-all-the-things trend. You're either on Team Starlink or Team Astronomy. Only two options. Pick a side, we're at war!!!
> And who knows,... one of those grad students could invent a way around it.
See? Shockingly common. :D
Even when we don't even have an idea, nevertheless we feel oddly compelled to suggest that maybe there's an easy ("grad student") solution that makes the scientific cost simply go away.
If we're willing to pay the cost in lost scientific data, then let's do it and say so. We shouldn't live in (oh so tempting!) denial about the downsides. That's all I'm saying.
Yes, but that's a system problem, not a user problem. The comment I replied to posited that a specific user would collect 5% less data. If you add ~5% to your grant proposal, you get the same amount of data.
As for the system problem, that is solved by building 5% more observing capacity. Or, more realistically, starting new telescope projects slightly earlier. This really isn't as complicated as you're trying make it out to be. Pot, meet kettle.
>As for the system problem, that is solved by building 5% more observing capacity.
If this is to somehow come from existing funding sources, I'll need a moment to pick myself up off the floor laughing. ;D Obviously those sources are already at their budget appetite.
Or maybe this an Efficient Market / Pigouvian suggestion, where megaconstellaton operators pay (and pass on to their customers) into an Astronomical Reparation Fund worth ~5% of current global astronomy funding, to be distributed to astronomical grants and construction of new observatories? Because sure, that seems fair.
If you truly believe (as do I) that we value internet access more than the loss of scientific data, then you'll agree the internet users can easily reimburse scientists for the damage and still come out ahead. "You broke it, you buy it."
> If you add ~5% to your grant proposal
..then I'll add 10% to mine!
It's a race to the bottom. Eventually folks get sick of it, so they enact rules and enforcement mechanisms to prevent padding. In the end all we accomplish is transforming an efficient & high-trust system into an overhead-laden, low-trust system.
> these days some of the best astronomy is performed by telescopes in space, so astronomy overall benefits by having easier access to space.
Public access satellites. The FCC requires broadcast licensees to demonstrate that they're acting "in the public interest". Should private rocket launches have to give a minimum amount of their payload to research and non-profit purposes?
Sure, why not? A Hubble-sized telescope is only about 12 tons, which is only about 70% the mass of what a Falcon 9 can deliver to low earth orbit, and SpaceX does that 100x per year (it's only May and they've launched 47 so far this year). For reference, Spitzer is 1 ton and Chandra is 6 tons.
The elephant in the room is that launching one Hubble per year to a Hubble-like orbit only uses about 1% of SpaceX's current annual demonstrated launch capacity, and the actual reason people are upset has little to do with the actual impact on astronomy and more do with wanting to punish a certain CEO. One new space telescope every year would completely revolutionize the field, yet he'd barely notice. Better think of something else.
Space telescopes cost billions of dollars not because of launch costs but because of all the dedicated engineering required to fit the telescope into the size and weight restrictions required for launch. In the past we've always been willing to go to extreme lengths to meet launch requirements (hand-made parts with exotic materials, folding mirrors with intricate deployment procedures, etc.).
If we instead design something to be mass-produced at a cost more commensurate with that of a Falcon 9 launch, then it may well be much better than Hubble in terms of bang for the buck, but it won't be as capable as Hubble in absolute terms. Even so, although Falcon 9 is very cost effective per unit weight compared to past rockets, it does not have a large payload volume compared to launch vehicles used for previous large space telescopes, and volume is usually what you need for space telescopes (because big mirrors are constrained by volume, not weight).
Once Starship becomes fully operational it will completely transform the landscape because it is not only low cost but the interior payload bay volume is much larger than existing rockets in all dimensions.
The upset is also because urban people or people in many denser areas generally don’t really benefit from Starlink etc. You can bet if those types of satellites were the only readable way for them to get internet, astronomy would suddenly fall way down on their list of priorities.
The thing is, paying SpaceX's going rate for launch only adds a tiny sliver to the cost of a "Hubble-sized" telescope. Launch costs have become very cheap thanks to SpaceX - whether they donate it or not is somewhat like an American family getting a 100% discount on rice...it's not going to change their overall monthly food costs, because rice is already so cheap.
I agree my aim is to make pretty pictures, and professional astronomy is to take accurate imagery, but up until I'm making subjective calls about colors, they're not too far apart before the image is stretched to a non linear histogram.
After all, I can't build pretty pictures on crappy data. Astrophotography is a heck of a lot of math
> the photo illustrations used in the article are selected to make things seem worse than they really are
Exactly. I do a LOT of astrophotography and satellite trails are actually very easy to get rid of. Even the stupidest, most naive outlier rejection techniques, such as taking a stack of tracked images, finding their mean and standard deviation, throwing out any data points outside of 2 standard deviations, and then re-averaging, will get rid of the satellites very cleanly. You can go to more advanced techniques such as doing linear fits and RANSAC and whatnot, but you get the idea.
NOT doing any outlier rejection, just taking the mean of all the images will show the satellite tracks, but very dimly. The people who are trying to make noise on social media deliberately and disingenuously take the max() instead of the mean() to make the problem seem worse than it is.
That said -- in all of my imaging sessions, aircraft are a much, much, much bigger problem than satellites, and still easy to deal with. Yet nobody makes any noise about aircraft.
Taking pretty pictures, and collecting scientific data are very different.
If a satellite is anywhere close to your target object in a frame you are using for photometry (measuring the amount of light), the frame is ruined, because it adds noise.
Seriously, any time you have >3 images to stack satellites and planes are a complete non issue. The median pixel value is always going to exclude those. Five images is enough to eliminate any trails even if they overlap between images.
Just do it in space and avoid the whole atmosphere and ground based light pollution. Space is cheaper than ever now, this is a problem for amateur astronomers, and hobbyists shouldn’t hold back progress.
Space imposes extraordinary costs and limitations which heavily precludes exploratory research. Instruments are built for space to achieve specific tasks which we know will be successful.
Instrument development has to first occur on earth-- including the research that lets us know which things will yield results deployed in space.
Astronomy aside, fleets of satellites once they turn to junk may eventually make further launching problematic.
SpaceX deliberately launches satellites into orbits which are too low to sustain on their own. Once the satellites run out of propellant, which happens after a few years of normal operation, they cannot remain in orbit indefinitely and eventually burn up in the atmosphere.
On very rare occasions, a launch malfunctions in such a way that the satellites end up in unintended orbits that do turn into long-term junk, but this is not the norm.
Their performance at cryogenic temperatures is quite good which is one reason why currently in design/construction scientific instruments are still using them.
The objects are so bright and so numerous that they corrupt an entire imagers data for the entire exposure. In a CCD rows and columns can become saturated and hot pixels can spill over into neighboring pixels (blooming). When the imagers for the LSST were being designed, it was not anticipated that they would have to deal with tens of thousands of hot fast moving objects.
On the one hand the constellations are doing considerable damage to surface based astronomy. On the other hand they are funding an enormously lower cost of access to orbit and beyond for astronomy up in the sky.
That needs some citations. The James Webb Telescope's mirror is 6.5m in diameter. It took decades and billions of dollars of overruns and a prayer to launch and work correctly. There is no hope of most hardware repairs.
That mirror size pails in comparison to what can be accomplished via ground based observatories for much, much cheaper.
And the available modes of operation are completely different between space and ground. For example, space observatories are using decades old instrumentation techniques, hardware, and software. And that's just for starters.
We cannot do astronomy via space exclusively.
For me personally, I never wanted to see something like Starlink with my bare eyes, and I have several times. It's beyond annoying to me that a company has been able to unilaterally pollute the Earth's sky.
> That needs some citations. The James Webb Telescope's mirror is 6.5m in diameter. It took decades and billions of dollars of overruns and a prayer to launch and work correctly. There is no hope of most hardware repairs.
Because it had to get launched folded up, because the launch vehicles were so space- and mass-constrained. The unfolding mechanism was enormously complicated and added to much of the cost.
Now we can send up bigger, heavier objects for much less money. The 6.5m mirror fits comfortably inside Starship's cargo bay, unfolded. JWST is a one-off clockwork masterpiece; future space telescopes will come off an assembly line. There will be thousands in orbit, pointed at every part of the heavens simultaneously.
The 39-meter primary mirror has 798 1.4-meter segments, each individually adjustable. The scaffolding required to hold all the segments is "significant" and must be assembled in orbit. We would stick this out next to the James Webb at L2, which means we would need the ability to travel to L2 to construct this mythical orbital extremely large telescope.
With our current technology, we can build ELT on Earth for a fraction of the cost of putting it in orbit.
For one thing, before this decade is out we will have the lift capacity to get an ELT-worth of mass to L2. And the lack of need to correct for atmospheric distortion would simplify the design considerably.
But it's beside the point. Such a singular mega-telescope would no longer be the only way to do astronomy in space. A world of radically lower launch costs gives more possibilities. We could have a fleet of thousands of independent small/medium sized space telescopes. That way, we wouldn't have to carefully ration imaging time between competing astronomy projects anymore. High quality data would become cheap and abundant, procured on-demand.
It doesn't simplify the design; it increases its complexity. All the problems of telescopes on Earth become significantly more problematic in space: temperature, flexure, warping, backlash, pointing models, optical alignment, and collimation are some of the issues.
Electronics, sensors, and consumables fail or run out, which means you need to be able to get there to fix things. Then, as research projects change, you need to change instruments.
Yes, one could have thousands of 1-5 m telescopes. A terrestrial scope is about an order of magnitude cheaper than an orbiting telescope. So, the big question is who will pay to replace the thousands of scopes in that size range that are already operating on Earth.
Rationing will still needed (Research projects always exceed the number of available scopes). High-quality data, will not be as cheap or abundant as you think it might be. With the number of scopes we are talking about and the sensors that astronomers use, we can expect hundreds or thousands of petabytes a second of data. How will we get that data down from orbit?
This is just one project. Could you imagine a thousand of these astronomical fire hoses running at the same time in orbit?
The next issue is where these telescopes should be placed. The more we learn about running telescopes in orbit, the more we realize that they need to be placed very far from Earth to increase the observable sky and the length of time one can study a chunk of it. As I said above, consumables need to be replaced, sensors need to be changed for the observing program, boils down to how you are going to get a repair crew out to wherever the telescopes are.
> Electronics, sensors, and consumables fail or run out, which means you need to be able to get there to fix things. Then, as research projects change, you need to change instruments.
So launch another. Launch capacity is getting cheap... let's use it.
Consider that 1% of SpaceX's annual launch capacity is enough to put one Hubble in orbit every year. Instead of sending astronauts to fix the fucked-up mirror, you just launch one with a not-broken mirror.
We as a planet don't even build that many ground-based telescopes with a 2.5m+ mirror each year. Think about how astronomy would change if you could just take every telescope we build today and put it in space.
This scope is not built for space travel. This model for space telescopes from NASA put a price tag on all the major components for building and operating a single space telescope is counted in billions. https://ntrs.nasa.gov/api/citations/20110015780/downloads/20...
A couple of things not covered in other comments are the costs of mission control and end-of-life deorbiting. It is far cheaper to rent a car, drive to an observatory, mount your evolving experiment on scope, and debug it on-site than to put the same experiment in orbit. Terrestrial telescope mission control is ad hoc and usually in a heated/air-conditioned shack on the mountaintop.
> With our current technology, we can build ELT on Earth for a fraction of the cost of putting it in orbit.
That's going to change soon. The reason the ELT needs individually adjustable panels is to provide corrections for refraction in the atmosphere as it swirls around. A space-ELT doesn't need that (well, maybe some cheap slow actuators to set the focus on a large non-rigid mirror).
As the cost of launches drop, we will hit a point where it is cheaper to put the telescope in space where you don't need those expensive atmosphere correctors.
Every 30-meter-class telescope uses segmented mirrors, because nobody knows how to make a single, monolithic 30-meter-diameter mirror.
It's only barely technically feasible to construct these 30-m telescopes on the ground. The idea that they can be constructed in space is just fanciful.
Yes, but in space the segments don't need real-time corrections for atmospheric effects (and the whole structure doesn't need to be built to withstand the strong winds at the top of a mountain). The idea that you can't build that in space is just naive.
It is not impossible. But you would have to design the telescope to be a rocketship complete with motors, fuel tanks, and all that other fun stuff. That would significantly increase the telescope's complexity to withstand the force and vibration of a rocket engine. Theoretically, one could use ion drives, but the engineering challenges of creating ion drives capable of moving a few hundred tons of telescope are significant.
It is much simpler to build the telescope equivalent of IKEA flatpack furniture and assemble it on-site than it is to build it and then move it.
Doesn't matter. The point is that, thanks to reusable boosters, launching satellite constellations, and other recent developments, space is becoming much cheaper - so if you can't fit 8 JWSTs in one Starship, just launch the rest on another, and it'll still come out cheaper than the original JWST.
Ultimately it becomes so cheap we'll be able to put workers up there to assemble and maintain the telescopes, just like on Earth. We might see telescopes in telescope farms near a small station for the workers. It might even be possible to send workers out to the Sun-Earth L2 point to maintain telescopes there.
mate I can't give you a citation for something that hasn't happened yet. it's a reasonable extrapolation of current trends. don't give me this "citation needed" whining.
If the promises made for new launch systems like SpaceX' Starship (and maybe even, one day, in some unknown future, Bezos' Blue Origin manages to launch something larger than a phallic pond hopper?) it should become radically less expensive to launch larger telescopes into orbit and/or to e.g. the moon.
That "should" needs a lot of backing up, and I don't understand why we need to singlehandedly rely on the same company creating the issues to apparently solve them with wishful thinking.
> I don't understand why we need to singlehandedly rely on the same company creating the issues to apparently solve them with wishful thinking.
It is because you did not start your own re-usable space vehicle company. Bezos did but thus far he seems to treat it as a billionaire's toy, throwing a few fellow class members just over the Kármán line. There's a few others making attempts to actually get to space - Rocket Labs etc. - but mostly it comes down to Musk's creation which opened the door to radically lower costs, i.e. without them the usual suspects would have had no reason to keep on pushing 70's technology at whatever price they manage to extract from the governments and the market.
The future of astronomy is both on the ground and in space.
There are so many things that you can only conceivably do from the ground. You can build vastly larger telescopes on the ground, you can install far heavier instruments (like cameras and spectrographs) on them, you can upgrade and repair components much more easily. You can build massive arrays of radio telescopes. You get the point.
There are some things you can only do from space, or that are better in space, but saying that everything will be done in space is like saying we only need laptops and don't need datacenters. You need both.
Yes, though I guess it depends on what you mean by lots: https://en.wikipedia.org/wiki/List_of_largest_optical_reflec.... Critically the 30+m monsters under construction have only recently become feasible on the Earh let alone in space, and much smaller instruments still provide significant value today.
There’s a much longer list of large radio based telescopes which have minimal advantages in space to the point where we haven’t launched any, and they are also negatively impacted by constellations. Also, several types of observations don’t really benefit from being in space. If you want to track killer asteroids space doesn’t provide much advantage even if you could get there for 100$/kg.
IMO the issue here isn’t satellites, it’s that they can harm multi billion dollar investments at zero cost to themselves. If you’re very clearly causing 10’s of millions in damages you really should be compensating the people affected.
> There’s a much longer list of large radio based telescopes which have minimal advantages in space to the point where we haven’t launched any
What if they could be put behind the Moon, completely shielding them from Earth RF emissions? It's been a cost-prohibitive idea now, but might not be for much longer.
The largest filled-aperture radio telescope in the world has a 500-meter diameter, and reportedly only cost $180 million. For comparison, the International Space Station costs $3 billion per year just to operate. Doing stuff in space is expensive.
For large (>10m) telescopes, it doesn't matter much, because no one is building rockets with big enough fairings. Even if the cost of launching to LEO was $0, in-orbit unfolding/assembly is a bottomless hole of engineering complexity that you cannot avoid. Again, see JWST/ISS.
I count 13 on wikipedia's list of the largest telescopes. There are 3 more currently under construction. The evocatively named "Extremely Large Telescope" is estimated to cost about $1 billion USD. Who knows how much it will actually cost, but for comparison, that's about $400 million less (adjusted for inflation) than the budgeted cost of the Webb telescope, which is about 1/6 the planned size (and therefore 1/36 the light collecting capability).
edit: italicized above. The Webb ended up costing $10 billion, so the savings could be even larger
But the point is that Webb was vastly over-engineered because we needed to get value out of every ounce of mass at the very high costs of legacy launch providers, and even more compromised because of Ariane 5’s tiny fairing.
You could build Webb for vastly, vastly less money if it launched on Starship, not just per unit of mass; volume is at much less of a premium in the new regime.
You can’t quite fit ELT pre-constructed into a single Starship, it’s true. But it’s built out of segmented mirrors. It doesn’t have to arrive on station in one piece.
Exactly my thoughts. Scientists drool at the few telescopes we have in orbit. If we could launch more of them for less money at the expense of a busier night sky I don't think they would want to miss on that
Growing up in a small town, I could see thousands of stars on a clear night. In a major metropolitan area where I live now, it’s hundreds. When I visited Beijing for three weeks, I think there was one night where the pollution cleared sufficiently to see any stars at all; I think I saw three or four.
LED’s are causing an exponential ramp in lighting pollution right now. (They’re more efficient, so people install them in more places and leave them on longer.)
People are convinced that their towns are "safer" if the lighting is bright enough to read a newspaper in the middle of every street in the middle of the night by street lamp alone, and think their oversized SUV seems tougher if the headlamps sear the eyeballs of everyone else on the road.
For actually necessary amounts of outdoor lighting at nighttime, LEDs are not any more power efficient than low-pressure sodium lamps, and considering how bright LEDs are often made, total power consumption is significantly higher.
The lighting industry has absolutely zero respect for human ergonomics, and is happy to sell as much new lighting as they can as often as they can with marketing spin built on pseudo-scientific nonsense. Surely there must be some engineers in the industry with basic understanding of human vision, but they aren't calling the shots. Policymakers are happy to channel Federal subsidies and local tax revenue through to the lighting industry, tossing out PR announcements about how "green" and "modern" they are being along the way.
The issue with LEDs is that they are broad spectrum, whereas sodium lights always fall in a very narrow band in the spectrum which is easily handled with a physical filter.
Exactly. My fondest memories of childhood stargazing was gathering people around me, pointing at the sky and asking them to look, just as a high-magnitude Iridium flare was starting. Heavens Above was my secret weapon for showing off in high school.
SpaceX single handedly made my whole family excited about space exploration. My mother watches every launch and landing, keeps track of Starlink satellites passing by and runs out with her phone camera every time they are visible.
She even started to learn English because she wanted to understand what they're saying on the live streams. I am fixing some production bug at 4 AM and suddenly she's texting me like "you're watching the launch too???". And last time I forgot to send her the link to the latest Starship test she nearly grounded me.
She is a seamstress who never cared about any of this until she saw the first landing of Falcon Heavy, proclaimed that we live in a fucking scifi and became the biggest Elon Musk fangirl I know.
NasaSpaceFlight, an independent space news group, has done wonders. They go the extra mile to explain everything, answer viewers questions, and even brought students' experiments to the 2nd Superheavy launch. They cover all space companies
It seems to me that one problem is that regular people who are interested in astronomy don't have access to space based telescopes. I'm not sure I'd want to live in a world where there's that degree of class divide between astronomers who do and do not have access to that kind of funding.
SpaceX built the biggest constellation to date, and is using the profits to build Falcons while designing Starships. Check out the resulting cost per kilo to orbit:
The cost of getting those into space is a relatively small part of the overall cost. The amount of cost benefit one of these telescopes would see just to the cost reductions gained specifically because of Starlink are insignificant.
> The cost of getting those into space is a relatively small part of the overall cost.
Well, technically, I suppose you could argue that the direct launch costs are small. However, most of the cost of the telescope itself are driven by the high launch costs.
That's the classic problem for satellites: Launch is expensive, so you can't afford to fail. So you have to use mil-spec everything. Every screw has to come with a piece of paper attesting to the provenance of the chromium used to make the stainless steel. Every system has to be built and tested and have triple redundancy. You have to use teflon-insulated wires, because god forbid anything outgases while on orbit. You have to over-build everything, and test all the vibration modes on those giant vibration tables NASA owns. So now "the satellite is expensive". Oh, and since the satellite is expensive, the launcher can't afford to fail and costs just spiral out of control.
But look what happens when you have cheap launches: You don't care if the satellite has a 1% chance of failing. If it does, learn from your mistake, make that one thing better and launch again. Now that you only need two nines instead of five, all of your costs go down. You can use regular-grade chips, and hardware store screws. Instantly the price of everything drops by several orders of magnitude.
The cost of launch is small-ish compared to the total program cost, but the limitations on launch condition the engineering requirements in ways that inflate the engineering costs. JWST had to be built as an insane on-orbit autonomous origami project because its mirror couldn't fit in a fairing unfolded. Repeat for ten thousand other decisions that are made in order to optimize weight or volume.
If you can launch a hundred tons to orbit for $5M, you can just make a huge dumb cheap telescope and throw a dozen of them up there. Quantity covers a multitude of sins.
>> Astronomy is also engaged in the search for extraterrestrial intelligence, a classic example of a program that might proceed for many years with little or nothing of interest to report, but that might someday provide one of the most profound discoveries in human history
That is all well and good. Most HN readers are probably well aware of that project. But if you want to alter policy at a national or international level, don't talk about extraterrestrial intelligence. It stirs the hornets next of faith, politics and cultural conflict. It opens the door to ridicule. Talk about the search for life, the search for a second life-supporting world. And maybe some of that life runs a radio station. Just avoid mentioning ET by name.
I'm sure it's inconvenient, but it's hard for me to believe that this isn't a solvable problem.
Satellites have extremely predictable paths and are very well-tracked by every government with a space program. If you can know a source of noise is there, you can trim the noise out of the signal. Sure, this impacts the fidelity of your signal for the three-dimensional coordinates of image where the noise was present, but "We're getting less science per day" isn't a reason to stop the low-orbit satellite boom.
What am I missing here? Can we not do the signal-subtraction? Is the problem unsolved or unsolvable? And if it's unsolved... Where are the grants to solve it?
When counting photons, the noise in your signal scales with the square root of the total count. If the satellite is dumping 100 ± 10 photons in every pixel it passes through, you can no longer distinguish objects so faint that they'd only leave 10 photons in a pixel during your exposure.
1) Most research is performed on the thousands of smaller telescopes (0.5-2 m.) scattered worldwide at private and public institutions. Even with the multitude of telescopes in the size range, there is still significant contention for scope time.
2) Space telescopes will never be disposable and will always require some form of service, even with high-reliability construction.
3) low Earth orbit is a limited resource and should be managed as a worldwide Commons. Allowing private corporations to occupy space is another way to privatize profit and push losses onto the public purse. Do you think any of these private companies will clean up the orbital messes they create, or will they act like they have to date?
4) Satellite Internet solves the billionaire's problem of extracting more money from users. Terrestrial methods for Internet access are good enough in all but the most remote communities. The main problem with terrestrial Internet is funding buildout Via private companies in a natural monopoly environment.
Is this a bit of a temporary problem, in the the very technology causing the issue - substantially cheaper access to space - will presumable ultimately put a frikkin massive telescope, or many massive telescopes into orbit where they’ll also not have to deal with the many other issues ground telescopes have to deal with.
I get that this still sucks for any individual with a Telescope though.
It's not just "any individual with a telescope" though. It's stuff like the Simonyi Survey Telescope, a set to map the southern sky down to below 27th magnitude that's in trouble.
How would a telescope like that compare to Webb or Hubble in its capability? Eg, if we had to trade the loss of that for many Webb scale telescopes, or presumably something much much bigger once starship can start launching - is that worth the trade?
Ok, who funds it? National Science Foundation doesn't allocate nearly enough money as it is, let alone enough to replace the tens to hundreds of active telescopes producing scientific data every night. And those telescopes are already oversubscribed with people waiting in line for available time. So unless we're slowing astronomy to a halt, we'd need similar numbers of telescopes.
And none of that takes into account that many of these telescopes are used specifically as experimenter telescopes where a given scientist can use their own equipment to perform unique observations that cannot be easily done with space-based telescopes.
It took over a decade to produce the Webb telescope and get it into space, and still is a massive feat of engineering not easily reproduced. We're not nearly to a point where we can just write off ground-based observatories in place of space-based ones.
My understanding (as a very amateur astrononer) is that it's an entirely different sort of scope - very wide field, with the ability to track extermely faint objects, rather than magnification of a much smaller field. I.e. we'd need to build and launch another immense scope to get the same sky-mapping ability.
As much as I sympathize this feels like a necessary evil to me in a sense vaguely accerlationism like.
I do think starlink can do more to help the situation though. Sure they tweaked some of the satellites to minimise it, but they could do more. Presumably the know the precise location and orientation of each sat. Surely that can be packaged into a data stream that helps unfk the images? Maybe with a sprinkling of that AI musk has going? Astronomers is a pretty small crowd...can't be that hard for someone like musk to throw them a bone that acknowledges that they're getting the short end here
There's no need to predict them in advance. Astronomy photos taken from the ground aren't one long exposure. They're lots - hundreds even - of short ones, which are then "stacked" to reduce noise and increase dynamic range of the final image.
It should be trivial to identify streaks in the stack and just throw out those images. I'd be surprised if they're not already doing that for the older satellites up there, and things like planes flying across the shot.
Mega-constellations also mean that access to space is getting cheeper. Bigger and more plentiful space telescopes should offset the loss from ground based astronomy in the long run. It's no consolation in the near term. But imagine the possibilities for a Starship sized telescope, or many of them.
No. The moon is tidally locked to the Earth, so its rotation exactly matches its orbital period. If you put a telescope on the far side, it'll always be pointing away from Earth.
I always thought spacex should stick a 5 dollar webcam to each sattelite pointing upwards and create the worlds largest telescope to just shut everybody up
Can you expand on how sticking a $5 webcam on each starlink satellite would quell concerns?
I’m in the astronomy community and I can’t quite figure it out. If you could expand on what you’re thinking and some of the science behind it, that’d be great.
Half baked for sure, but : I thought given the ultra precise location and clocks, combined with the laser coms you could build a large array, or a inferometer with a baseline the size of the leo orbit.
Could be used for whole sky surveys, transient detections, wide angle monitoring, and high res imaging (granted this last one might require more operational finesse than a 5 dollar webcam c ould give you since you'd need fractional wavelength accuracy (right?).
A radio antenna pointing outwards would in all honesty probably be better.
But 42.000 x X mega pixels in orbit pointing outwards at least will give you some nice big piles of data to play woth - and the downlink is baned in
I know it's a blessing for people who live out in the sticks to have internet.... but is that really such a large use-case to justify entire fleets of these things?
How hard is it to run km of wire from the nearest town?
To me, these were built for the sole purpose of surveillance, and internet is an afterthought.
Edit: yes yes it's expensive, but the easiest solution the world came up with was for some guy to invest billions in a satellite program?
You have to dig a trench or span the wire. Either way you need to clear it with numerous property owners over a vast distance, get approval from dozens of authorities along the way, coordinate work crews, and then do maintenance on the whole thing for decades.
And then you discover that the wire used 50 years ago contained lead and we don't like that anymore, so now you have to pay for massive lawsuits (look up AT&T & Verizon) and rip up all that wire. More coordinating work crews and property owners!
And then they invent a new kind of wire and you have to do it all again.
Launching 1000's of satellites isn't easy but I can see wanting to do that rather than wire up the whole planet.
(in the US) It may be hard for a new company but easy for existing telecom giants. But existing telecom giants don't give a shit about national internet infrastructure quality, so if connecting rural customers simply appears less profitable* than focusing on current operations[1], they won't do it.
[1] Current operations include the obviously profitable "send monthly marketing materials via mail, email, and live salespersons to homes who canceled your services the day they had an alternative," among other idiotic practices.
The hardest part is not the cable, or even the installation thereof, it's finding a contiguous right-of-way you can install it on, or having to fuss around with thousands of land owners who want their cut for the rights.
This is why most cables are laid alongside train tracks, not unlike telegram wires of years past. You negotiate with a handful of entities and can get permission relatively easily.
Of course, this presumes there's tracks, which is less and less likely as they keep getting ripped out.
If there's anything modern infrastructure build needs, it's more right-of-way access where you can provision dark fibre without getting mired in the legal issues.
To me, these are capitalistic solutions looking for problems. It's the whole startup mentality. Let's just throw a bunch of shit in space and see if it ends up being useful for anything. This idea of connecting the world is as false as the other hundred millions times that's been sold.
Useful for anything? Starlink useful to its 2.7 million subscribers. And it's already profitable. As of last year, SpaceX makes more in subscription fees than it costs to build and launch the satellites. The economics will only become more favorable when SpaceX improves their launch capabilities with Starship.
What environmental impact? So far there have been 162 Starlink launches. Each launch uses around 200 tons of RP-1, which is equivalent to the fuel capacity of a Boeing 747. In other words: A single 747 burns more fuel in a year than all the Starlink launches in the past five years.
Rocket launches are far more environmentally non-friendly than planes. You can't just look at fuel capacity. It's the composition and where the waste product gets dumped. Rockets dump their waste much higher up in parts of the atmosphere much more sensitive to it. Comparing a rocket and plane isn't an effective comparison in terms of environment impact. So this:
> A single 747 burns more fuel in a year than all the Starlink launches in the past five years.
is not an accurate summary of the environmental impact of rocket launches.
Also, rocket launches are incredibly disruptive to the local ecosystems of the launch sites.
> is not an accurate summary of the environmental impact of rocket launches.
So what is the accurate summary of the environmental impact of rocket launches? 10 times more than B747? 100 times? How would it look compared to aviation?
> rocket launches are incredibly disruptive to the local ecosystems of the launch sites.
Not according to FAA when they issued license for SpaceX's launches at KSC - [0]
You can just search for it. The general answer is that it is not good, and it's getting worse. The comparison to aviation, once again, is not really needed. Aviation is extremely polluting and damaging to the environment (not just poluttants but also disease and invasive seed spreading). There's nonquestion about that. But it isn't related to rocket launches anymore than other pollution.
What's more, and this is touched some in the articles, deorbiting satellites so routinely is dumping toxic metals and plastics into the upper atmosphere at increasing rates. We're literally turning the atmosphere into a burn skyfill.
> Not according to FAA when they issued license for SpaceX's launches at KSC
The FAA is not an environmental or even scientific agency. Additionally, the FAA has revealed itself to be a captured regulator in several instances. There's no question that it is susceptible to political and monetary pressures.
Well the goal of SpaceX is to launch as many rockets as technically possible. Even if SpaceX could only reach the same impact as the rest of the aviation sector, that would be infinitely too much. The aviation sector is already a problem.
Falcon 9's exhaust is almost entirely carbon dioxide and water vapor. If anything the exhaust is less polluting than aircraft or combustion vehicles, as air-breathing engines create nitrogen oxides.
And yet, that's not true. One of the primary impacts from rocket launches are the heights they reach and the particles they produce, as mentioned in the articles I posted elsewhere.
I'm not sure how the existence of subscribers and profit negates the point. Their are plenty of things that have those that aren't useful beyond a capitalistic sense.
SpaceX provides internet access. Millions of customers pay for it. The revenue from the customers is more than enough to cover the business costs. The negative externalities are much smaller than say... aircraft or cargo shipping. If a sustainable business like that isn't enough to justify usefulness, then what is?
Starlink is not there to bring Internet in places that don't have it. It's here to bring fast Internet in places that already have slow Internet.
The question is: how fast an Internet connection do we need? Do we really need to swipe 4k videos on social network, or to download 50G of docker containers for every build? I don't think so.
I say there is one: survival. Not only of our species, but of the others, too. We're failing at that, and the vast majority of the technology that got developed in the last decades is making things worse.
OK, but I don’t think tech progress = dead ecosystem.
In fact, newer tech tends to be cleaner. We use less land than we would’ve using 1800’s farming techniques, for instance. Nuclear is cleaner than coal.
Also, everybody having more money is a huge help for the environment. Compare the size of the green movements between say, Sweden and the DRC.
Yes, more money = more consumption, but it also means we can do innovative things in a better way.
In this particular case, surely extra-planetary infrastructure is better than millions of miles of ditches with lead cables in them.
Either way, our current state of development isn’t sustainable. It has to be millions of times smaller, or an unknown amount larger. I vote for more tech.
I feel like I almost agree with everything you say, except that I systematically conclude the exact opposite. You seem to keep stopping half-way through every single point you mention:
> In fact, newer tech tends to be cleaner.
Newer tech is cleaner if you ignore rebound effect. It's absolutely certain that in history, new tech has always resulted in more energy use, which is the exact opposite of "cleaner".
> Also, everybody having more money is a huge help for the environment. Compare the size of the green movements between say, Sweden and the DRC.
Everybody having more money means that they can consume more. Do you know who goes on holiday by plane? Those who have more money. It's absolutely clear that those who have more money pollute more, even if they feel good because they drive a Tesla (which is all but environmentally-friendly).
> Yes, more money = more consumption, but it also means we can do innovative things in a better way.
Okay, it is "better" by many metrics. But certainly not by the environmental one. We are talking about the environmental impact here, right? Starlink is technically impressive, but it doesn't mean we should do it. It's just part of the problem, and we don't need it.
> In this particular case, surely extra-planetary infrastructure is better than millions of miles of ditches with lead cables in them.
Surely? It's all but sure. You don't even say precisely what you are talking about: do you account for the cables that are already out there and work perfectly fine? Or do you just consider the cost of bringing fiber to your tent in the middle of the desert? Maybe Starlink is better for that, but we don't need it. In fact we just can't afford it, at this point.
> Either way, our current state of development isn’t sustainable. It has to be millions of times smaller, or an unknown amount larger. I vote for more tech.
This is preposterous. With our current understanding of physics, more tech will certainly not help. We would need a breakthrough that is akin to wishing for a miracle. You may as well wait for Jesus to come back.
But there is more: our society depends on fossil fuels. But not only there is no serious way to replace them entirely (meaning that we cannot save the climate/biodiversity without fundamentally changing society), but they are limited and will become a problem in the next few decades (meaning that society will fundamentally change, whether we want it or not).
You can wait for a miracle, or face the truth: we need to prepare for a world with (much) less energy. And in that world, there is no place for fiber in your tent in the desert.
> We're massively more connected than ever before.
In a certain electronic sense, yes, but emotionally and socially, we are not more connected than ever before. So like I said, this utopian promise of the Internet connecting and liberating and educating us has not happened. In fact, it's the opposite that has happened.
Yeah, this. And people ignoring this point or actively downvoting it ... that's not just puzzling it's symptomatic.
The capitalism I'm fine with, though we need the New Deal version to come back. But universal isolation and depression, or feeling like we live in a factory farm, no.
Yeah, I’m not sure why trenching is so expensive, I think PG&E was quoting something silly like millions per kilometer. I’m planning on doing like a tenth of a kilometer in a day with a $400 trencher rental pretty soon. I’m sure it’s not apples to apples, but the delta there seems pretty baffling.
For me, the biggest hang up has just been that I’m required by the state to get it inspected before I put in the conduit, and that ramps up the complexity of coordinating things quite a bit, because I’d rather not leave it open too long. If they have to deal with a bunch of bureaucratic coordination, then I could see the actual labor becoming a relatively tiny part of the difficulty/cost.
Yeah, but if the planning that’s meant to make things efficient is using up almost all the money, seems like maybe we need to rethink how we’re doing things.
In many cases, the issue isn't cost to run but cost to maintain.
Consider South Africa, where the largest threat to installation deployment is inability to police the entire deployment coupled with massive wealth inequality... People just dig the cables out of the ground for the copper. Cellular radio has ameliorated the issue some (harder to steal the repeater antenna out of the back yard of a shotgun-owning resident), but Internet can still be a challenge.
30 years ago, it was possible to be lost - not because you wanted to be, but because you had no way of figuring out where we are. GPS and other GNSS networks have solved that problem.
It used to be possible to not have high-speed internet, and now high-speed Internet is available everywhere in the world that has an amenable government.
Right now, it's possible to be in a location where it's impossible to call for help. In a few years, when LTE-in-space is available and the 911 mandate applies to it, anyone with a charged phone will be able to get contact.
Imagine a radio telescope as a satellite constellation, with an aperture the diameter of the orbit if you can synchronize the incoming signal with the right math...
The article definitely gets this part right:
> “Some astronomers see this as a true ‘hair on fire’ emergency, heralding irretrievable losses to space science; others present a more sanguine face, depicting this as yet another challenge to be surmounted in surveying a decreasingly pristine sky,” Koplow remarks.
Being involved in both space and astronomy plants me squarely in the latter camp. It takes a bit more work and software, but having so many satellites in space is a surmountable challenge for terrestrial astronomers. (Not to mention, these days some of the best astronomy is performed by telescopes in space, so astronomy overall benefits by having easier access to space.)