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Nearly 1 in 3 Starlink satellites detected within the SKA-Low frequency band

188 points by aragilar 1y ago

mentalgear 1y ago
[flagged]
jillesvangurp 1y ago
Mitigation is going to be the name of the game. Whether they like it or not, low earth orbit (LEO) is becoming a very busy place and it's not just SpaceX launching lots of little satellites there. The Chinese are very busy launching their own satellites into LEO. And there are other companies and countries doing or considering the same. Spacex and Star link get most of the attention; but the Chinese are doing a decent job to keep up with them in number of launches. And there are a growing number of companies with LEO launch capability. Mitigation might have to involve some sacrifices. I don't see how policy is going to be able to mitigate much here. And of course the Chinese are under no obligation to listen to US policy makers. They might have their own debates domestically around this topic and they might be reasonable about the topic internationally even. But building international consensus; or even enforcing what little there is on that front could be challenging. A more practical approach might be accepting that earth based observations are inevitably going to suffer a bit as the number of satellites grows from thousands to tens of thousands and eventually well beyond that. Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. That's already happening of course. And otherwise, astronomy is very interesting and cool but mostly it concerns observations about things that are really really far away and not directly relevant to a lot of things on earth. Unless of course the thing under observation is on a collision course with us.
- squigz 1y ago
  Why do we have to launch tens of thousands or even more satellites?
  - mlindner 1y ago
    "We" don't have to launch anything at all. SpaceX needs to launch enough satellites to satisfy customer demand for their constellation. In general the trend actually is that SpaceX is launching fewer but larger satellites (initially they were doing 60 satellites per launch, but they made them larger and now launch 24-28 satellites depending on the orbit inclination.
  - JonChesterfield 1y ago
    This internet fad seems to be hanging around and bandwidth is probably linear in satellite count.
  - jocaal 1y ago
    Why do we need radio telescopes. Satellite communications are infinitely more useful for people on earth than some research papers about things light-years away
    - voxlax 1y ago
      Yes, but if it hadn't been for the efforts of visionary scientists at NASA trying to reach the stars, there would be no means of putting those satellites into orbit.
      - brookst 1y ago
        This is the but I don’t see the relevance. Is there an argument / position there or just an observation?
        flufluflufluffy 1y ago
        The point is basic science (e.g. radio astronomy) is, if not necessary, then highly desirable, because it can lead to unimaginable advancements in humanity (or in a country’s technological and military capabilities if that’s how you think).
        1y ago
- aragilar 1y ago
  A bit, it's 5 orders of magnitude over the required SNR?! From the article: "The authors estimate a lower limit of 93 Jy per beam in the frequency averaged images containing Starlink emission. Considering just 1 mJy of radio frequency interference could mess up an EoR power spectrum integration, this could severely affect SKA-Low EoR science."
  - jillesvangurp 1y ago
    > the required SNR Require by who and on what authority? My point here was not to contest that but make the point that the cat is out of the bag and that it is indeed impacting SKA-Low EoR science and the people involved with that have to deal with that. Getting the cat a little bit back in the bag via policy and other means is maybe worth trying (good luck) but I don't give it a very high chance of success.
    - 1dom 1y ago
      This makes me want to say "is nothing sacred?!" I get your point from a pragmatic: this is the world we live in, work with it, not against it. I think you need to scope this approach when suggesting it though, since it's effectively "a policy has been broken by a company, but we can't undo it, so lets just accept it and let them get on with it" which doesn't seem like it'll lead to a better world. I do agree with your point that the people who suffer from the policy breach have to be pragmatic in their handling. But ultimately, let's not let pragmatism and stoicism lead to businesses spectacularly breaking policies in hopes of being told "well the cats out the bag now, the victims can deal with it, you might has well continue".
      - rickdeckard 1y ago
        > I do agree with your point that the people who suffer from the policy breach have to be pragmatic in their handling. But ultimately, let's not let pragmatism and stoicism lead to businesses spectacularly breaking policies in hopes of being told "well the cats out the bag now, the victims can deal with it, you might has well continue". I fully agree, and that's IMO the core-issue here: This strong-arm approach of just forcing the problem to be solved in your favor by scaling as fast as possible and then pleading how uneconomic it would be for you to change course, insisting that the other side should be pragmatic about this. I don't remember this was a working strategy in the past (imagine a car-company just accelerating sales of a faulty car to scale THEIR issue and avoid having to do a recall), but nowadays it could even be turned into a geopolitical topic...
- perihelions 1y ago
  > "The Chinese are very busy launching their own satellites into LEO." The Chinese (correctly) view these satellite constellations as a key military capability, and have gone all-in on creating their own version. (I mean, I don't see how that's even debatable at this point—having seen the influence of Starlink in Ukraine. Future conflicts will only amplify the gap between the haves and have-nots). They haven't yet launched a large number (~120); they don't now have the launch volume for large-scale satellite constellations. Their race is to first catch up in launch capability. They have dozen private startups—heavily subsidized and favored by the state—in the race to build a viable, reusable launcher comparable to Falcon 9, that they would then use to launch Starlink-like constellations at the same cadence. Some starting points: https://www.wsj.com/world/china/chinas-own-elon-musks-are-racing-to-catch-up-to-spacex-74b02a95 https://www.wsj.com/world/china/chinas-own-elon-musks-are-ra... ( https://archive.is/Ukmoa https://archive.is/Ukmoa ) ("China’s Own Elon Musks Are Racing to Catch Up to SpaceX / Private sector takes bigger role in building reusable rockets, advancing Beijing’s goal of independence from Western technology") https://www.nytimes.com/interactive/2025/07/23/world/asia/starlink-spacex-musk-china-satellites.html https://www.nytimes.com/interactive/2025/07/23/world/asia/st... ("This Was Supposed to Be the Year China Started Catching Up With SpaceX / It’s looking unlikely. Here’s why")
- velox 1y ago
  > Including astronomy related hardware Can't feasibly do VLBI or other radio astronomy at useful scale in space even if launches were free. Look up the scale of SKA or the EHT.
  - galangalalgol 1y ago
    Geosynchronous satellites could give us even longer baselines couldn't they? Or even at l4 and l5. They don't get shielded by the earth like l2, but the station keeping would be easier. That would be a massive baseline
    - velox 1y ago
      Baselines are one thing, you need a huge collecting area to get useful sensitivity, which there is barely budget for to build on earth, let alone in space
  - perihelions 1y ago
    I'm not clear why not. The scale of the completed SKA-low (512*256 = 131,072 antennas, 1.8 meter lengths) is the same as that of Starlink itself. It's even less mass; the antenna parts alone, they are wire dipoles, they say they only weigh 1.6 kg each. https://arxiv.org/abs/2301.06708 https://arxiv.org/abs/2301.06708 Why can't humanity launch 2^17 small antennas into deep space, as a free-floating constellation?
    - deleted 1y ago
      [deleted]
    - thicktarget 1y ago
      It's just nowhere near feasible. Each element would need power, orientation, precise positioning and a data link to the processing stations. For SKA low the raw data rate from all antennas is something like 2 Pb/s. Which is more than all of Starlink combined. Which is massively stepped down to 7 Tb/s by the central processor, a supercomputer with purpose built signal processing hardware. Then the next stage takes it to 100 Gb/s. You would likely have to transmit the data via radio links, which would defeat the purpose of going to space. When a radio telescope is built in space it will likely be on the Moon (or in orbit), designed for lower frequencies and much less ambitious than SKA low.
- geraneum 1y ago
  > But building international consensus; or even enforcing what little there is on that front could be challenging. No kidding! If something is worthwhile, people should and sometimes do go to the trouble! Just roll over is not good advice here!
- sneak 1y ago
  > Spacex and Star link get most of the attention; but the Chinese are doing a decent job to keep up with them in number of launches. Nobody anywhere is anywhere near SpaceX’s launch cadence, reusable or non.
- elcritch 1y ago
  > Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. That's already happening of course. Seems more effective for astronomers to embrace it. Perhaps by getting SpaceX to add a few dozen hundred satellites kitted out for radio astronomy. Link them together and it could be amazing for radio astronomy!
- barbazoo 1y ago
  > Luckily we now are able to launch stuff into orbit a lot cheaper. “We” as in the select few countries that have the launch capability and the space tech. Again a public good is being commoditized and being sold to the highest bidder.
  - MichaelZuo 1y ago
    This seems circular… since the lack of a worldwide authority, that can decide the value of X public good is worth more than zero, is the issue in the first place.
  - Mathnerd314 1y ago
    I thought that was the whole idea of spectrum auctions.
    - blackguardx 1y ago
      The RF spectrum is a public good in the US and there are requirements placed on the winners of those auctions to demonstrate it provides some public benefit. A company can't just buy spectrum and sit on it, for example. They must use start to use it in a certain timeframe.
      - ggreer 1y ago
        The RF spectrum is a common good, not a public good. Public goods are non-excludable and non-rivalrous. The RF spectrum is non-excludable (anyone can transmit on any frequency, given the right equipment) but rivalrous (transmitting on one frequency prevents others from using that frequency). Requiring the winner of a spectrum auction to use it is a way to prevent anti-competitive tactics (since the government is granting a monopoly to the winner). The goal is to incentivize productive use of limited resources, not necessarily to benefit everyone. In theory, the winner could use the spectrum for entirely internal purposes. Though in real world spectrum auctions, the government usually has stipulations such as requiring interoperability or using open standards. This reduces the value that the government captures, but likely increases the value that is created overall. Before spectrum auctions, the government simply mandated what frequency bands were used for what, and by whom. Getting access usually meant lobbying and back room deals. Sometimes the FCC used lotteries, which caused speculators to enter lotteries and then license access (basically capturing revenue that would have gone to the government had the spectrum been auctioned). In practice, auctions are the worst form of spectrum allocation, except for all the others.
- uv-depression 1y ago
  Ah, the techbro defence. "We already started doing it, so I guess you're just going to have to let us". > Whether they like it or not, A swarm of LEO satellites because in the current political climate it's easier to massively pollute orbits and prevent astronomy than do municipal internet is not, in fact, a law of nature; nor is it inevitable. > But building international consensus; or even enforcing what little there is on that front could be challenging. Ah, a challenge! Let's all give up immediately; this could make some rich people a lot of money, after all! > Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. Would you like to pay for launching Vera C. Rubin (8.4m, nearly 20,000kg for just the camera and mirrors) into space? How about the TMT (30m, expected ~2.6 million kg)? Truly spoken like someone who knows nothing about astronomy. > And otherwise, astronomy is very interesting and cool but mostly it concerns observations about things that are really really far away and not directly relevant to a lot of things on earth. Apparently fundamental physics is not very relevant to us here on Earth! This is one of the most small-minded statements I've ever read.
- insane_dreamer 1y ago
  How do the various LEO constellations mitigate band interference issues? Does the US/China have some agreement as to which bands their respective countries' companies will use?
- butlike 1y ago
  You just made me realize that the younger generation is never going to be able to reliably "wish upon a <shooting> star" ever again.
- stronglikedan 1y ago
  We're fucked once they have the ability to launch payloads that are too big and/or beefy to fully burn up on reentry.
- saddat 1y ago
  No , regulation. That’s what is necessary for cars, planes etc , otherwise the competition would lead to low emission cars . Plus the space debris creation , which is also unregulated , but threatening humanity - for profit
- rlt 1y ago
  > Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. Honestly once Starship is operational SpaceX should subsidize launches of non-commercial astronomy hardware. Could build some goodwill to offset the negatives.
deleted 1y ago
[deleted]
willis936 1y ago
When an individual transmits on a band they shouldn't the FCC issues a fine. When a company transmits on a band they shouldn't the FCC gives them the band. https://www.pcmag.com/news/despite-spacex-protests-fcc-clears-ast-spacemobiles-massive-satellite https://www.pcmag.com/news/despite-spacex-protests-fcc-clear... Comment period ended in July. https://www.fcc.gov/ecfs/search/search-filings/results?q=(proceedings.name:(%2225-201%22)) https://www.fcc.gov/ecfs/search/search-filings/results?q=(pr...
- axus 1y ago
  Wise of them to launch FM1 on an Indian rocket, then.
  - pdabbadabba 1y ago
    If they want to serve the U.S. market, which they do, they still have to deal with the FCC and comply with U.S. regulations, regardless of the launching country.
    - axus 1y ago
      The wisdom was not launching a satellite on their competitor's rocket.
- perihelions 1y ago
  > "When a company transmits on a band they shouldn't" The source article is quite clear there's no regulatory violations here. > "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;" > "The detected IEMR and UEMR are outside of the frequency bands protected for radio astronomy, but are at frequencies of great interest for key experiments for the SKA-Low facility, and at frequencies where RQZ protections at the SKA-Low site are in place;"
  - rickdeckard 1y ago
mlindner 1y ago
I'm not sure why they're complaining when the SKA isn't even active yet. Once it's active Starlink will do just like they have for other radio telescopes, avoid transmitting while they're in the boresight and in general don't transmit toward the antenna. This is a well practiced interaction at this point with scientific agencies in multiple countries. The only thing that they can't stop would be things like reflected unrelated ground communications off of the satellite, but that would be very weak.
- aragilar 1y ago
  Uh, given there's been radio telescopes there for longer than starlink has existed, I'm not sure why they haven't stopped broadcasting in that area then.
  - mlindner 1y ago
    It's possible they haven't requested it yet. I've only heard SKA complaining loudly in the media while American radio telescopes have very obvious blackouts visible on SpaceX's map because they've requested them.
    - aragilar 1y ago
      So everyone needs to go beg every single satellite provider to respect the well known existing radio quiet zones? I suspect it's more likely Starlink is ignoring all other regulators and regulations other than the FCC, hence why the US-based observatories are considered.
      - mlindner 1y ago
        There's several blackout holes in Europe as well. Two in Germany, one in Spain and one in Sweden.
- rickdeckard 1y ago
  > avoid transmitting while they're in the boresight and in general don't transmit toward the antenna Not sure this will help against the mentioned unintentional electromagnetic radiation (UEMR) likely caused by the electronics of the satellites themselves. "This radio emission at lower frequencies from Starlink isn’t their downlink frequency, but instead unintentional electromagnetic radiation (UEMR), thought to be caused by the onboard electronics of the satellite."
nothankyou777 1y ago
Google says their 8,094 satellites use phased arrays. I wonder what would happen if you directed a few hundred of these phased arrays at a single target?
- ben_w 1y ago
  Less than you may expect: https://en.wikipedia.org/wiki/Thinned-array_curse https://en.wikipedia.org/wiki/Thinned-array_curse
  - deleted 1y ago
    [deleted]
  - IshKebab 1y ago
    Not relevant. That's talking about if you just move the array elements, not if you add more. However the answer is still that nothing will happen. The power level on the ground is extremely weak.
  - msgodel 1y ago
    I think most people assume the individual satellites aren't synchronized well enough to produce a mutually coherent signal so the power from each of them will just be normally superimposed. IE they're thinking of the individual phased arrays as just highly directional antennas for the satellites. The idea that they could be coherent actually means there could be more power than we might expect.
    - londons_explore 1y ago
      With any kind of feedback from the ground (to compensate for atmospheric effects), I think these could easily be coherent. One just needs timing accurate to 100 picoseconds within one 20 millisecond round trip - which is 5 ppb and the cheapest atomic clocks can do that. Even so, my guess is you aren't going to be frying an egg 500 km away even with the whole starlink constellation at full power!
  - nothankyou777 1y ago
LargoLasskhyfv 1y ago
[flagged]
cryptoshadow 1y ago
Good
fidotron 1y ago
There are several related things I find odd about Starlink, with the ongoing defense of the impact it has on scientific research being one of them. Having used it it is genuinely impressive, but it will inevitably lead to everyone wanting their own independent LEO constellation for military purposes (communication and observation), which will then lead to a big interest in anti-satellite weapons since these will become major targets in a hot war. The end result here is going to be huge quantities of space junk and investment in defense over-the-horizon ground radios (again) which to some degree is already happening.
- flufluflufluffy 1y ago
  I agree. The sky is gonna be so full of sh*t in the future
- TMWNN 1y ago
  >which will then lead to a big interest in anti-satellite weapons since these will become major targets in a hot war If anything, the other way around. Were Starlink a traditional satellite constellation, with a few in geosynchronous orbit, they would be very appealing targets. But there are thousands, and soon tens of thousands, of Starlink satellites, which makes any sort of weapon against them other than maybe a laser impractical. >The end result here is going to be huge quantities of space junk ... the Starlink portion of which naturally falls back to earth within five years.
- theultdev 1y ago
  It's impossible for VLEO constellations to create space junk. They naturally fall out of orbit after a few years. And no they can't be "blown into" GEO orbit.
  - maxglute 1y ago
    Big % of mega constellations will be be >500km where deorbit is decades to centuries. Unless regulatory changes, VLEO will be minority because orbit slots is limited.
philipallstar 1y ago
> This radio emission at lower frequencies from Starlink isn’t their downlink frequency, but instead unintentional electromagnetic radiation (UEMR), thought to be caused by the onboard electronics of the satellite. This UEMR is not currently regulated by the International Telecommunications Union (ITU), the organization responsible for managing and allocating the radio spectrum for various uses. Feels like this is regulatory UB, and therefore allowed.
rickdeckard 1y ago
I'm curious to see how this will play out. I don't see big potential for the current US government to value scientific interests higher than the interests of SpaceX. Wouldn't be surprised if SpaceX just continues to launch such satellites causing unintentional interference, to then claim in case of escalation how uneconomic it will be for them to correct this issue now and how the financial impact to SpaceX needs to be valued higher than scientific needs. This LEO Direct-to-cellular strategy seems to play out similarly, with SpaceX launching massive amounts of satellites which are technically not capable to prevent interference on private spectrum while crossing country-borders, so ITU/FCC/CEPT now need to find a solution to deal with this situation.
- throw0101a 1y ago
  > I don't see big potential for the current US government to value scientific interests higher than the interests of SpaceX. Do not underestimate the motivating factor of spite in the current US administration.
  - burkaman 1y ago
    Spite about what? Elon hasn't done a single thing to harm the administration. The bill he claimed to dislike passed easily, he stopped talking about Epstein as soon as it seemed like it might cause actual problems for the president, and in the past couple days he's expressed very vocal support for the Texas gerrymandering effort and domestic deployment of the military in DC. He continues to be the administration's most powerful and influential supporter in the world.
    - JumpCrisscross 1y ago
      > Elon hasn't done a single thing to harm the administration Literally reïgnited the Epstein drama.
      - iAMkenough 1y ago
        They've made up since, with a plan to use the drama and outrage to disparage and prosecute political opponents of the President. Congress and Trump-appointed judges seem to be acting in support of that approach so far.
crest 1y ago
If Starlink / SpaceX interferes ground based scientific observations they should be required to pay in kind and launch orbital observatories as compensation.
- fidotron 1y ago
  The other NRO telescope would be a nice start: https://en.wikipedia.org/wiki/2012_National_Reconnaissance_Office_space_telescope_donation_to_NASA https://en.wikipedia.org/wiki/2012_National_Reconnaissance_O...
- 93po 1y ago
  i'm positive spacex would be thrilled to launch something like a JWST and get to write off the $150-$220 million launch "value", which is what the Ariane 5 ECA costs. since it'd only cost them as low as $10 million with reuse. the tax write-off would benefit them immensely
pfdietz 1y ago
If it's unintended emission this seems like something that can be reduced by refinement of the satellite design.
Catbert59 1y ago
That's weird. The company I'm working for has its own EMC chamber (maintaining that huge room fully calibrated and standardized is ultra expensive... just looking at these EMC test receivers that go up to 40GHz my me cry in $$$$) and we invested giant engineering effort into our products to be far below every radiation limit norm in the world. Shouldn't satellite companies have even better stuff and more strict regulations or are these unintended effects maybe caused by the harsh environment?
- inemesitaffia 1y ago
  They did. These are sub 1 Ghz bands and the issue is from the engines and (maybe power supply)
- financetechbro 1y ago
  I’m certain that SpaceX does not care about regulations
- parsimo2010 1y ago
  Most communications satellites (which is all Starlink really is) are heavily focused on their operating bands and any specific bands they are told not to interfere with so they can get launch approval. There's no benefit to doing anything extra. And not only do they have to be told which specific bands they can't interfere with, the government actually has to require delivery of test results or else that is the same as giving permission to interfere. Most companies won't spend a penny, take a second of time, or add a gram to a satellite if it doesn't affect their mission or chance of approval. Especially not one as cost-optimized as SpaceX. They won't change a thing unless the US government forces them to do so, or if they think that a government order is imminent so they come to some voluntary agreement ahead of time to avoid what would probably be a more constraining official regulation in the future. The actual issue is probably caused by switch-mode power supplies or some digital signal on the satellite that isn't fully shielded, possibly one that does digital control of a motor or thruster. It probably isn't the communication radios since they operate at a much higher frequency. You can fix the issue by adding filtering and/or shielding, but that takes extra components (meaning extra cost and weight) and requires testing (meaning time). Plus you have to identify the offending system, which means you have to start with testing and detective work. This interference was only detected on some Starlink satellites, so you have to do detective work to find out if it is a particular operating mode or generation of satellite that is offending, do testing to confirm it, and then work on a fix.
macinjosh 1y ago
The function these satellites serve is 1000x more valuable than the cost of inconveniencing a few astronomers. Rural communities are being enriched all over the world through high speed internet access.
- emushack 1y ago
  I think I have a different idea of "valuable". Rural communities need connectivity for sure - but we also need reliable radio astronomy for a whole host of reasons - space weather forcasting, terrestrial weather forecasting, scientific advancement.... without radio astronomy, there wouldn't even be satellites to put cat videos on!
  - trothamel 1y ago
    Huh? How does radio astronomy affect space or terrestrial weather forecasting?
    - emushack 1y ago
      https://public.nrao.edu/ask/can-radio-telescopes-be-used-in-meteorology/ https://public.nrao.edu/ask/can-radio-telescopes-be-used-in-...
- uv-depression 1y ago
  Launching tens of thousands of satellites is better than municipal internet, which would serve the same purpose, be cheaper, and not interfere with critical scientific research? This solution is better only for the private internet oligopolies. I would say astronomical research is orders of magnitude more important than that.
aurizon 1y ago
I have often wondered if a a very small Ion thruster, used intermittently, gravitationally stabilised, could be used to offset the variable atmospheric drag caused by inflation/deflation of the tenuous upper atmosphere to extend satellite life. It would add a little weight at launch but could extend orbital life by many years. It would need fractions of a gram of thrust, run off the current solar electricity budget, and could easily make them endure for 10+ years. When the satellite had failed or aged out, it could be used for improved de-orbiting at end of life. I also suspect that a mobile stream at a lower frequency could be added that would provide intermittent stream down loads of news directly to the Russian people via recently tested cell phone comms ability
- vardump 1y ago
  > I have often wondered if a a very small Ion thruster, used intermittently, gravitationally stabilised, could be used to offset the variable atmospheric drag caused by inflation/deflation of the tenuous upper atmosphere to extend satellite life. Isn't that exactly what Starlink is doing?
  - brcmthrowaway 1y ago
    starlink sats have thrusters?
    - MarkusQ 1y ago
      Yes. https://www.reddit.com/r/SpaceXLounge/comments/11cnh0w/starlink_20_mini_with_new_argon_hall_thurster/ https://www.reddit.com/r/SpaceXLounge/comments/11cnh0w/starl...
      - aurizon 1y ago
        Yes, I see, dated 2018 using rarified air as ion source. Totally solves the reaction mass needs and the electricity is solar
    - literalAardvark 1y ago
aaron695 1y ago
[dead]
mwachs 1y ago
These rudeboys better pick it up, pick it up!

188 points by aragilar 1y ago

[flagged]

Mitigation is going to be the name of the game. Whether they like it or not, low earth orbit (LEO) is becoming a very busy place and it's not just SpaceX launching lots of little satellites there. The Chinese are very busy launching their own satellites into LEO. And there are other companies and countries doing or considering the same. Spacex and Star link get most of the attention; but the Chinese are doing a decent job to keep up with them in number of launches. And there are a growing number of companies with LEO launch capability. Mitigation might have to involve some sacrifices. I don't see how policy is going to be able to mitigate much here. And of course the Chinese are under no obligation to listen to US policy makers. They might have their own debates domestically around this topic and they might be reasonable about the topic internationally even. But building international consensus; or even enforcing what little there is on that front could be challenging. A more practical approach might be accepting that earth based observations are inevitably going to suffer a bit as the number of satellites grows from thousands to tens of thousands and eventually well beyond that. Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. That's already happening of course. And otherwise, astronomy is very interesting and cool but mostly it concerns observations about things that are really really far away and not directly relevant to a lot of things on earth. Unless of course the thing under observation is on a collision course with us.

squigz 1y ago
Why do we have to launch tens of thousands or even more satellites?
- mlindner 1y ago
  "We" don't have to launch anything at all. SpaceX needs to launch enough satellites to satisfy customer demand for their constellation. In general the trend actually is that SpaceX is launching fewer but larger satellites (initially they were doing 60 satellites per launch, but they made them larger and now launch 24-28 satellites depending on the orbit inclination.
- JonChesterfield 1y ago
  This internet fad seems to be hanging around and bandwidth is probably linear in satellite count.
- jocaal 1y ago
  Why do we need radio telescopes. Satellite communications are infinitely more useful for people on earth than some research papers about things light-years away
  - voxlax 1y ago
    Yes, but if it hadn't been for the efforts of visionary scientists at NASA trying to reach the stars, there would be no means of putting those satellites into orbit.
    - brookst 1y ago
      This is the but I don’t see the relevance. Is there an argument / position there or just an observation?
      - flufluflufluffy 1y ago
        The point is basic science (e.g. radio astronomy) is, if not necessary, then highly desirable, because it can lead to unimaginable advancements in humanity (or in a country’s technological and military capabilities if that’s how you think).
        1y ago
aragilar 1y ago
A bit, it's 5 orders of magnitude over the required SNR?! From the article: "The authors estimate a lower limit of 93 Jy per beam in the frequency averaged images containing Starlink emission. Considering just 1 mJy of radio frequency interference could mess up an EoR power spectrum integration, this could severely affect SKA-Low EoR science."
- jillesvangurp 1y ago
  > the required SNR Require by who and on what authority? My point here was not to contest that but make the point that the cat is out of the bag and that it is indeed impacting SKA-Low EoR science and the people involved with that have to deal with that. Getting the cat a little bit back in the bag via policy and other means is maybe worth trying (good luck) but I don't give it a very high chance of success.
  - 1dom 1y ago
    This makes me want to say "is nothing sacred?!" I get your point from a pragmatic: this is the world we live in, work with it, not against it. I think you need to scope this approach when suggesting it though, since it's effectively "a policy has been broken by a company, but we can't undo it, so lets just accept it and let them get on with it" which doesn't seem like it'll lead to a better world. I do agree with your point that the people who suffer from the policy breach have to be pragmatic in their handling. But ultimately, let's not let pragmatism and stoicism lead to businesses spectacularly breaking policies in hopes of being told "well the cats out the bag now, the victims can deal with it, you might has well continue".
    - rickdeckard 1y ago
      > I do agree with your point that the people who suffer from the policy breach have to be pragmatic in their handling. But ultimately, let's not let pragmatism and stoicism lead to businesses spectacularly breaking policies in hopes of being told "well the cats out the bag now, the victims can deal with it, you might has well continue". I fully agree, and that's IMO the core-issue here: This strong-arm approach of just forcing the problem to be solved in your favor by scaling as fast as possible and then pleading how uneconomic it would be for you to change course, insisting that the other side should be pragmatic about this. I don't remember this was a working strategy in the past (imagine a car-company just accelerating sales of a faulty car to scale THEIR issue and avoid having to do a recall), but nowadays it could even be turned into a geopolitical topic...
perihelions 1y ago
> "The Chinese are very busy launching their own satellites into LEO." The Chinese (correctly) view these satellite constellations as a key military capability, and have gone all-in on creating their own version. (I mean, I don't see how that's even debatable at this point—having seen the influence of Starlink in Ukraine. Future conflicts will only amplify the gap between the haves and have-nots). They haven't yet launched a large number (~120); they don't now have the launch volume for large-scale satellite constellations. Their race is to first catch up in launch capability. They have dozen private startups—heavily subsidized and favored by the state—in the race to build a viable, reusable launcher comparable to Falcon 9, that they would then use to launch Starlink-like constellations at the same cadence. Some starting points: https://www.wsj.com/world/china/chinas-own-elon-musks-are-racing-to-catch-up-to-spacex-74b02a95 https://www.wsj.com/world/china/chinas-own-elon-musks-are-ra... ( https://archive.is/Ukmoa https://archive.is/Ukmoa ) ("China’s Own Elon Musks Are Racing to Catch Up to SpaceX / Private sector takes bigger role in building reusable rockets, advancing Beijing’s goal of independence from Western technology") https://www.nytimes.com/interactive/2025/07/23/world/asia/starlink-spacex-musk-china-satellites.html https://www.nytimes.com/interactive/2025/07/23/world/asia/st... ("This Was Supposed to Be the Year China Started Catching Up With SpaceX / It’s looking unlikely. Here’s why")
velox 1y ago
> Including astronomy related hardware Can't feasibly do VLBI or other radio astronomy at useful scale in space even if launches were free. Look up the scale of SKA or the EHT.
- galangalalgol 1y ago
  Geosynchronous satellites could give us even longer baselines couldn't they? Or even at l4 and l5. They don't get shielded by the earth like l2, but the station keeping would be easier. That would be a massive baseline
  - velox 1y ago
    Baselines are one thing, you need a huge collecting area to get useful sensitivity, which there is barely budget for to build on earth, let alone in space
- perihelions 1y ago
  I'm not clear why not. The scale of the completed SKA-low (512*256 = 131,072 antennas, 1.8 meter lengths) is the same as that of Starlink itself. It's even less mass; the antenna parts alone, they are wire dipoles, they say they only weigh 1.6 kg each. https://arxiv.org/abs/2301.06708 https://arxiv.org/abs/2301.06708 Why can't humanity launch 2^17 small antennas into deep space, as a free-floating constellation?
  - deleted 1y ago
    [deleted]
  - thicktarget 1y ago
    It's just nowhere near feasible. Each element would need power, orientation, precise positioning and a data link to the processing stations. For SKA low the raw data rate from all antennas is something like 2 Pb/s. Which is more than all of Starlink combined. Which is massively stepped down to 7 Tb/s by the central processor, a supercomputer with purpose built signal processing hardware. Then the next stage takes it to 100 Gb/s. You would likely have to transmit the data via radio links, which would defeat the purpose of going to space. When a radio telescope is built in space it will likely be on the Moon (or in orbit), designed for lower frequencies and much less ambitious than SKA low.
geraneum 1y ago
> But building international consensus; or even enforcing what little there is on that front could be challenging. No kidding! If something is worthwhile, people should and sometimes do go to the trouble! Just roll over is not good advice here!
sneak 1y ago
> Spacex and Star link get most of the attention; but the Chinese are doing a decent job to keep up with them in number of launches. Nobody anywhere is anywhere near SpaceX’s launch cadence, reusable or non.
elcritch 1y ago
> Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. That's already happening of course. Seems more effective for astronomers to embrace it. Perhaps by getting SpaceX to add a few dozen hundred satellites kitted out for radio astronomy. Link them together and it could be amazing for radio astronomy!
barbazoo 1y ago
> Luckily we now are able to launch stuff into orbit a lot cheaper. “We” as in the select few countries that have the launch capability and the space tech. Again a public good is being commoditized and being sold to the highest bidder.
- MichaelZuo 1y ago
  This seems circular… since the lack of a worldwide authority, that can decide the value of X public good is worth more than zero, is the issue in the first place.
- Mathnerd314 1y ago
  I thought that was the whole idea of spectrum auctions.
  - blackguardx 1y ago
    The RF spectrum is a public good in the US and there are requirements placed on the winners of those auctions to demonstrate it provides some public benefit. A company can't just buy spectrum and sit on it, for example. They must use start to use it in a certain timeframe.
    - ggreer 1y ago
      The RF spectrum is a common good, not a public good. Public goods are non-excludable and non-rivalrous. The RF spectrum is non-excludable (anyone can transmit on any frequency, given the right equipment) but rivalrous (transmitting on one frequency prevents others from using that frequency). Requiring the winner of a spectrum auction to use it is a way to prevent anti-competitive tactics (since the government is granting a monopoly to the winner). The goal is to incentivize productive use of limited resources, not necessarily to benefit everyone. In theory, the winner could use the spectrum for entirely internal purposes. Though in real world spectrum auctions, the government usually has stipulations such as requiring interoperability or using open standards. This reduces the value that the government captures, but likely increases the value that is created overall. Before spectrum auctions, the government simply mandated what frequency bands were used for what, and by whom. Getting access usually meant lobbying and back room deals. Sometimes the FCC used lotteries, which caused speculators to enter lotteries and then license access (basically capturing revenue that would have gone to the government had the spectrum been auctioned). In practice, auctions are the worst form of spectrum allocation, except for all the others.
uv-depression 1y ago
Ah, the techbro defence. "We already started doing it, so I guess you're just going to have to let us". > Whether they like it or not, A swarm of LEO satellites because in the current political climate it's easier to massively pollute orbits and prevent astronomy than do municipal internet is not, in fact, a law of nature; nor is it inevitable. > But building international consensus; or even enforcing what little there is on that front could be challenging. Ah, a challenge! Let's all give up immediately; this could make some rich people a lot of money, after all! > Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. Would you like to pay for launching Vera C. Rubin (8.4m, nearly 20,000kg for just the camera and mirrors) into space? How about the TMT (30m, expected ~2.6 million kg)? Truly spoken like someone who knows nothing about astronomy. > And otherwise, astronomy is very interesting and cool but mostly it concerns observations about things that are really really far away and not directly relevant to a lot of things on earth. Apparently fundamental physics is not very relevant to us here on Earth! This is one of the most small-minded statements I've ever read.
insane_dreamer 1y ago
How do the various LEO constellations mitigate band interference issues? Does the US/China have some agreement as to which bands their respective countries' companies will use?
butlike 1y ago
You just made me realize that the younger generation is never going to be able to reliably "wish upon a <shooting> star" ever again.
stronglikedan 1y ago
We're fucked once they have the ability to launch payloads that are too big and/or beefy to fully burn up on reentry.
saddat 1y ago
No , regulation. That’s what is necessary for cars, planes etc , otherwise the competition would lead to low emission cars . Plus the space debris creation , which is also unregulated , but threatening humanity - for profit
rlt 1y ago
> Luckily we now are able to launch stuff into orbit a lot cheaper. Including astronomy related hardware. Honestly once Starship is operational SpaceX should subsidize launches of non-commercial astronomy hardware. Could build some goodwill to offset the negatives.

deleted 1y ago

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willis936 1y ago

When an individual transmits on a band they shouldn't the FCC issues a fine. When a company transmits on a band they shouldn't the FCC gives them the band. https://www.pcmag.com/news/despite-spacex-protests-fcc-clears-ast-spacemobiles-massive-satellite https://www.pcmag.com/news/despite-spacex-protests-fcc-clear... Comment period ended in July. https://www.fcc.gov/ecfs/search/search-filings/results?q=(proceedings.name:(%2225-201%22)) https://www.fcc.gov/ecfs/search/search-filings/results?q=(pr...

axus 1y ago
Wise of them to launch FM1 on an Indian rocket, then.
- pdabbadabba 1y ago
  If they want to serve the U.S. market, which they do, they still have to deal with the FCC and comply with U.S. regulations, regardless of the launching country.
  - axus 1y ago
    The wisdom was not launching a satellite on their competitor's rocket.
perihelions 1y ago
> "When a company transmits on a band they shouldn't" The source article is quite clear there's no regulatory violations here. > "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;" > "The detected IEMR and UEMR are outside of the frequency bands protected for radio astronomy, but are at frequencies of great interest for key experiments for the SKA-Low facility, and at frequencies where RQZ protections at the SKA-Low site are in place;"
- rickdeckard 1y ago

mlindner 1y ago

I'm not sure why they're complaining when the SKA isn't even active yet. Once it's active Starlink will do just like they have for other radio telescopes, avoid transmitting while they're in the boresight and in general don't transmit toward the antenna. This is a well practiced interaction at this point with scientific agencies in multiple countries. The only thing that they can't stop would be things like reflected unrelated ground communications off of the satellite, but that would be very weak.

aragilar 1y ago
Uh, given there's been radio telescopes there for longer than starlink has existed, I'm not sure why they haven't stopped broadcasting in that area then.
- mlindner 1y ago
  It's possible they haven't requested it yet. I've only heard SKA complaining loudly in the media while American radio telescopes have very obvious blackouts visible on SpaceX's map because they've requested them.
  - aragilar 1y ago
    So everyone needs to go beg every single satellite provider to respect the well known existing radio quiet zones? I suspect it's more likely Starlink is ignoring all other regulators and regulations other than the FCC, hence why the US-based observatories are considered.
    - mlindner 1y ago
      There's several blackout holes in Europe as well. Two in Germany, one in Spain and one in Sweden.
rickdeckard 1y ago
> avoid transmitting while they're in the boresight and in general don't transmit toward the antenna Not sure this will help against the mentioned unintentional electromagnetic radiation (UEMR) likely caused by the electronics of the satellites themselves. "This radio emission at lower frequencies from Starlink isn’t their downlink frequency, but instead unintentional electromagnetic radiation (UEMR), thought to be caused by the onboard electronics of the satellite."

nothankyou777 1y ago

Google says their 8,094 satellites use phased arrays. I wonder what would happen if you directed a few hundred of these phased arrays at a single target?

ben_w 1y ago
Less than you may expect: https://en.wikipedia.org/wiki/Thinned-array_curse https://en.wikipedia.org/wiki/Thinned-array_curse
- deleted 1y ago
  [deleted]
- IshKebab 1y ago
  Not relevant. That's talking about if you just move the array elements, not if you add more. However the answer is still that nothing will happen. The power level on the ground is extremely weak.
- msgodel 1y ago
  I think most people assume the individual satellites aren't synchronized well enough to produce a mutually coherent signal so the power from each of them will just be normally superimposed. IE they're thinking of the individual phased arrays as just highly directional antennas for the satellites. The idea that they could be coherent actually means there could be more power than we might expect.
  - londons_explore 1y ago
    With any kind of feedback from the ground (to compensate for atmospheric effects), I think these could easily be coherent. One just needs timing accurate to 100 picoseconds within one 20 millisecond round trip - which is 5 ppb and the cheapest atomic clocks can do that. Even so, my guess is you aren't going to be frying an egg 500 km away even with the whole starlink constellation at full power!
- nothankyou777 1y ago

LargoLasskhyfv 1y ago

[flagged]

cryptoshadow 1y ago

Good

fidotron 1y ago

There are several related things I find odd about Starlink, with the ongoing defense of the impact it has on scientific research being one of them. Having used it it is genuinely impressive, but it will inevitably lead to everyone wanting their own independent LEO constellation for military purposes (communication and observation), which will then lead to a big interest in anti-satellite weapons since these will become major targets in a hot war. The end result here is going to be huge quantities of space junk and investment in defense over-the-horizon ground radios (again) which to some degree is already happening.

flufluflufluffy 1y ago
I agree. The sky is gonna be so full of sh*t in the future
TMWNN 1y ago
>which will then lead to a big interest in anti-satellite weapons since these will become major targets in a hot war If anything, the other way around. Were Starlink a traditional satellite constellation, with a few in geosynchronous orbit, they would be very appealing targets. But there are thousands, and soon tens of thousands, of Starlink satellites, which makes any sort of weapon against them other than maybe a laser impractical. >The end result here is going to be huge quantities of space junk ... the Starlink portion of which naturally falls back to earth within five years.
theultdev 1y ago
It's impossible for VLEO constellations to create space junk. They naturally fall out of orbit after a few years. And no they can't be "blown into" GEO orbit.
- maxglute 1y ago
  Big % of mega constellations will be be >500km where deorbit is decades to centuries. Unless regulatory changes, VLEO will be minority because orbit slots is limited.

philipallstar 1y ago

> This radio emission at lower frequencies from Starlink isn’t their downlink frequency, but instead unintentional electromagnetic radiation (UEMR), thought to be caused by the onboard electronics of the satellite. This UEMR is not currently regulated by the International Telecommunications Union (ITU), the organization responsible for managing and allocating the radio spectrum for various uses. Feels like this is regulatory UB, and therefore allowed.

rickdeckard 1y ago

I'm curious to see how this will play out. I don't see big potential for the current US government to value scientific interests higher than the interests of SpaceX. Wouldn't be surprised if SpaceX just continues to launch such satellites causing unintentional interference, to then claim in case of escalation how uneconomic it will be for them to correct this issue now and how the financial impact to SpaceX needs to be valued higher than scientific needs. This LEO Direct-to-cellular strategy seems to play out similarly, with SpaceX launching massive amounts of satellites which are technically not capable to prevent interference on private spectrum while crossing country-borders, so ITU/FCC/CEPT now need to find a solution to deal with this situation.

throw0101a 1y ago
> I don't see big potential for the current US government to value scientific interests higher than the interests of SpaceX. Do not underestimate the motivating factor of spite in the current US administration.
- burkaman 1y ago
  Spite about what? Elon hasn't done a single thing to harm the administration. The bill he claimed to dislike passed easily, he stopped talking about Epstein as soon as it seemed like it might cause actual problems for the president, and in the past couple days he's expressed very vocal support for the Texas gerrymandering effort and domestic deployment of the military in DC. He continues to be the administration's most powerful and influential supporter in the world.
  - JumpCrisscross 1y ago
    > Elon hasn't done a single thing to harm the administration Literally reïgnited the Epstein drama.
    - iAMkenough 1y ago
      They've made up since, with a plan to use the drama and outrage to disparage and prosecute political opponents of the President. Congress and Trump-appointed judges seem to be acting in support of that approach so far.

crest 1y ago

If Starlink / SpaceX interferes ground based scientific observations they should be required to pay in kind and launch orbital observatories as compensation.

fidotron 1y ago
The other NRO telescope would be a nice start: https://en.wikipedia.org/wiki/2012_National_Reconnaissance_Office_space_telescope_donation_to_NASA https://en.wikipedia.org/wiki/2012_National_Reconnaissance_O...
93po 1y ago
i'm positive spacex would be thrilled to launch something like a JWST and get to write off the $150-$220 million launch "value", which is what the Ariane 5 ECA costs. since it'd only cost them as low as $10 million with reuse. the tax write-off would benefit them immensely

pfdietz 1y ago

If it's unintended emission this seems like something that can be reduced by refinement of the satellite design.

Catbert59 1y ago

That's weird. The company I'm working for has its own EMC chamber (maintaining that huge room fully calibrated and standardized is ultra expensive... just looking at these EMC test receivers that go up to 40GHz my me cry in $$$$) and we invested giant engineering effort into our products to be far below every radiation limit norm in the world. Shouldn't satellite companies have even better stuff and more strict regulations or are these unintended effects maybe caused by the harsh environment?

inemesitaffia 1y ago
They did. These are sub 1 Ghz bands and the issue is from the engines and (maybe power supply)
financetechbro 1y ago
I’m certain that SpaceX does not care about regulations
parsimo2010 1y ago
Most communications satellites (which is all Starlink really is) are heavily focused on their operating bands and any specific bands they are told not to interfere with so they can get launch approval. There's no benefit to doing anything extra. And not only do they have to be told which specific bands they can't interfere with, the government actually has to require delivery of test results or else that is the same as giving permission to interfere. Most companies won't spend a penny, take a second of time, or add a gram to a satellite if it doesn't affect their mission or chance of approval. Especially not one as cost-optimized as SpaceX. They won't change a thing unless the US government forces them to do so, or if they think that a government order is imminent so they come to some voluntary agreement ahead of time to avoid what would probably be a more constraining official regulation in the future. The actual issue is probably caused by switch-mode power supplies or some digital signal on the satellite that isn't fully shielded, possibly one that does digital control of a motor or thruster. It probably isn't the communication radios since they operate at a much higher frequency. You can fix the issue by adding filtering and/or shielding, but that takes extra components (meaning extra cost and weight) and requires testing (meaning time). Plus you have to identify the offending system, which means you have to start with testing and detective work. This interference was only detected on some Starlink satellites, so you have to do detective work to find out if it is a particular operating mode or generation of satellite that is offending, do testing to confirm it, and then work on a fix.

macinjosh 1y ago

The function these satellites serve is 1000x more valuable than the cost of inconveniencing a few astronomers. Rural communities are being enriched all over the world through high speed internet access.

emushack 1y ago
I think I have a different idea of "valuable". Rural communities need connectivity for sure - but we also need reliable radio astronomy for a whole host of reasons - space weather forcasting, terrestrial weather forecasting, scientific advancement.... without radio astronomy, there wouldn't even be satellites to put cat videos on!
- trothamel 1y ago
  Huh? How does radio astronomy affect space or terrestrial weather forecasting?
  - emushack 1y ago
    https://public.nrao.edu/ask/can-radio-telescopes-be-used-in-meteorology/ https://public.nrao.edu/ask/can-radio-telescopes-be-used-in-...
uv-depression 1y ago
Launching tens of thousands of satellites is better than municipal internet, which would serve the same purpose, be cheaper, and not interfere with critical scientific research? This solution is better only for the private internet oligopolies. I would say astronomical research is orders of magnitude more important than that.

aurizon 1y ago

I have often wondered if a a very small Ion thruster, used intermittently, gravitationally stabilised, could be used to offset the variable atmospheric drag caused by inflation/deflation of the tenuous upper atmosphere to extend satellite life. It would add a little weight at launch but could extend orbital life by many years. It would need fractions of a gram of thrust, run off the current solar electricity budget, and could easily make them endure for 10+ years. When the satellite had failed or aged out, it could be used for improved de-orbiting at end of life. I also suspect that a mobile stream at a lower frequency could be added that would provide intermittent stream down loads of news directly to the Russian people via recently tested cell phone comms ability

vardump 1y ago
> I have often wondered if a a very small Ion thruster, used intermittently, gravitationally stabilised, could be used to offset the variable atmospheric drag caused by inflation/deflation of the tenuous upper atmosphere to extend satellite life. Isn't that exactly what Starlink is doing?
- brcmthrowaway 1y ago
  starlink sats have thrusters?
  - MarkusQ 1y ago
    Yes. https://www.reddit.com/r/SpaceXLounge/comments/11cnh0w/starlink_20_mini_with_new_argon_hall_thurster/ https://www.reddit.com/r/SpaceXLounge/comments/11cnh0w/starl...
    - aurizon 1y ago
      Yes, I see, dated 2018 using rarified air as ion source. Totally solves the reaction mass needs and the electricity is solar
  - literalAardvark 1y ago

aaron695 1y ago

[dead]

mwachs 1y ago

These rudeboys better pick it up, pick it up!