Impacts of Large Satellite Constellations on Astronomy

[jebbo]

And Keck!

Indeed! I've had HIRES stuff and a bunch of AO from Keck during follow-up on planet hunting ...

Okay, but the wavelength thing is kind of massive.  You can't do JWST on the ground.

I know - I was just irritated with the space telescopes (ab)solves everything argument ...

Lots of wavelengths are only accessible from outside the atmosphere - but there is still lots to do in the accessible wavelengths (e.g. the transient sky; enter LSST - one of the worst affected by constellations, I think).

On defeatism: I don't think I am, but the solution isn't the exceptionally expensive single instruments we're currently building. Sure they can do fabulous things, access wavelengths we simply can't see from inside the atmosphere, and I love them, fully support them and want more.

But to overcome the increasing challenges of constellations** etc we need far more than this handful. We need a thriving space-based economy where we can do the things we do on Earth to build large scale telescopes. And to me, that means a sustained large lunar presence capable of supporting building and staffing observatories. Think Paranal / La Silla on the Moon

Is it a wildly optimistic dream? Yes, and I probably won't live to see it as it feels 30 - 50 years away but still ...

** which I think are inevitable; Starlink in Ukraine has just proved their strategic value.

--- Tony

[SpaceCadet1980]

Strangely, my bias is shared by plenty of knowledgeable opinions in the industry (and certainly academic circles), while the *opposite bias* is usually promoted by spokesmen of a strong agenda, or is just capitalizing on lack of immediate real-world data and litigiousness spirit on the part bearing the damages.

Respectable people in industry and academic circles aren't making false statements and relying on namecalling and similar behavior. So no, they clearly do not share whatever is driving you to make your posts here.

Regarding my language: "élites" is name-calling now? Wow I must be getting old, or maybe it's the acute accent that's too posh? I'm mirroring the many comments on this thread calling astronomers "entitled group who had it good for too long" and similar. You can look them up, it's not difficult to find them in practically every page of this thread, even if a fair number of the most out-there posts, by users who anyway still keep merrily posting abundantly, were deleted. Instead, the nth message by people like meekGee (^^hi there, won't even bother answering) do use pretty straightforward swear words like *piece of shit*. Not very corageous of him to use the acronym though, must be to protect the children.

Elites was just a quick way to reference a good portion of your post based purely on effectively personal attacks. The fact that you compared what you said to deleted posts just shows that you know that this is inappropriate behavior. No reason for me to even look for examples that might not even exist, as I don't remember seeing any such examples, only things that you might be completely misrepresenting for the countless time.

5G at those frequencies might not have existing sold devices *in the US*, but there are also other countries which use nearby frequencies within Starlink's or OneWeb's bandwidth (10.7 - 12.7 GHz) and have sold equipment with huge market penetration. I know the complaint I alluded to refers to a US spectrum litigation, but what makes it different in other parts of the planet for a service that aspires to be global from day 1 like megaconstellations, apart from not being able to influence the outcome as much there?

So you are admitting that you knew your argument was wrong and irrelevant yet you made it anyway? That is called lying.

If you want to discuss other country's regulations you are going to have to be specific, because when I just checked, this is a satellite reserved band in Europe too. And when you bring up your examples, keep in mind for your claims to have any relevance and even the tiniest grain of truth, they would have to be specifically 5G applications somewhere, and not heavily restricted on power to prevent interference with satellite usage.

5G will conceivably be serving a larger amount of people who might otherwise not have access to reliable internet, regardless of them living in crowded areas, because they might not be able to afford good quality, high-speed service with current networks, or they might get saturated by top users otherwise. If we're gauging a system as preferential by the size of its user base, megaconstellations serving a few million people should yield way hard to 5G serving hundreds of millions of them, if not billions. Moreover, with 5G being short-range and intended for high-density areas, as you point out, remote underserved areas should get minimal interference by definition! Are you sure I'm the one with the backwards argument?

You are using wrong numbers again, just Starlink should be serving tens of millions of people at a minimum. 5G simply won't be providing home internet to billions, and you are simply ignoring the fact that I already mentioned that there is no reason to expect this to be any different than all of the other terrestrial systems that have failed to meet their promises of providing service to underserved populations, the vast majority of 5G users will already have other options. You are also ignoring the fact I already mentioned that nobody else is using this frequency for 5G. 5G can do whatever it will do without this one company trying to change the rules to fix its broken business model.

And yes, yours is the backwards argument. People in cities will get 5G without these frequencies. And some number will also have the option of satellite internet as well. These frequencies used for 5G would purely kill competition.

As for the need to change out the satellites if the 5G proponents get their way, I thought one of the strongest selling points for megaconstellations was that they were cheaper than less damaging terrestrial alternatives, hardware was inexpensive and easily upgradable (some may say demisable). Now their business model becomes obsolete if someone else dares as much as touch the fringe of their spectrum in areas where they don't intend their main business to lie.

This is complete gibberish, upgradeable and demiseable aren't even vaguely related concepts. And I didn't say anything about needing to change out satellites. Doing so wouldn't fix the problem, because there is no other frequency available for them to switch to. Calling it the fringe of their spectrum is a plain lie, this is directly blocking them from a large portion of the spectrum they have available.

[Robotbeat]

People used to say the whole “don’t kid yourself” line about megaconstellations (“Teledesic failed! Just not viable.”) And then Starlink/OneWeb happened.

Patronizing defeatism.

OneWeb went bankrupt and is now living on bailout funding, so skepticism seems warranted.  Is Starlink profitable yet?  Probably not given this start up cost phases (they have 400,000 customers but want 40 million).  It must have a good chance at future profitability or SpaceX wouldn't be so committed.  In addition, the satellite mass production line is winning the company other, DoD work, which may pay off bigger.

 - Ed Kyle

If Starlink fails, then the problem to astronomy goes away, now, doesn’t it?


People dismissive of large in-space telescopes (which are perfectly feasible with Starship) and fearmongering about massive versions of Starlink (which requires Starship to work) are being inconsistent.

Pick one. Do you think Starship will work, and the big version of Starlink will happen therefore large in-space telescopes like LUVOIR or even larger become feasible, or do you think big telescopes won’t happen, you dismiss the idea of Starship and therefore the big version of Starlink will never happen?

Pick one! Or you’re all just fearmongering.

[Robotbeat]

Big space telescopes are perfectly feasible if Starship works.

[SpaceCadet1980]

Lots of wavelengths are only accessible from outside the atmosphere - but there is still lots to do in the accessible wavelengths (e.g. the transient sky; enter LSST - one of the worst affected by constellations, I think).

If I have followed the updates correctly, the updates from Starlink, in particular lowering the altitude, have gotten to the point that a relatively minimal amount of science will be impacted (I seem to remember a fraction of a percent in one analysis, but could be confused.)

I think the most impacted type of science done on the ground remaining may be asteroid searches, which need to use near the horizon near dusk/dawn. I think this is a prime example of where we really could use space based telescopes anyway, the continuous operation, not having the horizon restriction, and ability to use more infrared wavelengths should let even a single satellite make up for a lot of ground based data, and catch things that might never be seen from the ground. Last I checked, our asteroid surveys are fairly far along and we probably need a satellite to make any more big leaps in detections.

On defeatism: I don't think I am, but the solution isn't the exceptionally expensive single instruments we're currently building. Sure they can do fabulous things, access wavelengths we simply can't see from inside the atmosphere, and I love them, fully support them and want more.

But to overcome the increasing challenges of constellations** etc we need far more than this handful. We need a thriving space-based economy where we can do the things we do on Earth to build large scale telescopes. And to me, that means a sustained large lunar presence capable of supporting building and staffing observatories. Think Paranal / La Silla on the Moon

Is it a wildly optimistic dream? Yes, and I probably won't live to see it as it feels 30 - 50 years away but still ...

** which I think are inevitable; Starlink in Ukraine has just proved their strategic value.

--- Tony

As long as Starship works out we could be starting that thriving space based economy within 10 years. In the mean time, the current reductions in launch costs should enable some less expensive and exquisite space telescopes that will be a net positive, though clearly not a 1 to 1 replacement. At least until someone puts tens of thousands of satellites at 1000+ km which is where it sounds like actually large impacts will be expected. I'm not betting on any of the plans to do that actually happening particularly soon.

[Lee Jay]

People used to say the whole “don’t kid yourself” line about megaconstellations (“Teledesic failed! Just not viable.”) And then Starlink/OneWeb happened.

Patronizing defeatism.

Remember what I said that about:  "And don't kid yourself.  Telescopes like the Subaru, VLT, GMT and EELT aren't going to space anytime soon."

Show me a large scope (8m or larger) that's funded and when it's going to space.

[Lee Jay]

Big space telescopes are perfectly feasible if Starship works.

GMT is 22m in diameter and composed of 7 8.4m diameter monolithic mirrors weighing 17 tons each and EELT is 39m in diameter. Starship is 9m in diameter.

[meekGee]

Why is this so complicated?

A) In-space is a better observation location for a whole bunch of reasons.

B) On-Earth is an easier place to build a telescope so you can have more of them and they're bigger.

C) Starship-like capabilities (or rather, Starship) makes in-space telescopes easier, so moves the needle in the direction of A, which is a win.

It doesn't do away with ground based instruments and it's not the end of terrestrial astronomy...  It'll just allow for more and more powerful orbital telescopes.

The argument for how starlink hurts terrestrial telescopes is weak. For any ground location, at any given time there are only 4-9 Starlinks within line of sight above about 30 degrees of the horizon. Their locations and velocities are precisely known in advance. Only some of them are lit, and only during limited hours, and generally towards the sun.

If you want to get lit Starlinks to photobomb your images, it's super easy since that information is available to anyone.  But you can also use that same information to avoid having your images ruined. Free choice is good.

[Robotbeat]

Big space telescopes are perfectly feasible if Starship works.

GMT is 22m in diameter and composed of 7 8.4m diameter monolithic mirrors weighing 17 tons each and EELT is 39m in diameter. Starship is 9m in diameter.

So you’re telling me a couple of Starship launches could launch all the Gemini telescope mirrors, even without lightweighting (since they don’t need to have as thick in space to avoid gravity sag)?

[Robotbeat]

People used to say the whole “don’t kid yourself” line about megaconstellations (“Teledesic failed! Just not viable.”) And then Starlink/OneWeb happened.

Patronizing defeatism.

Remember what I said that about:  "And don't kid yourself.  Telescopes like the Subaru, VLT, GMT and EELT aren't going to space anytime soon."

Show me a large scope (8m or larger) that's funded and when it's going to space.

Show me a reason to be concerned about the full Starlink v2 constellation after it has already launched… same silly argument.

[Greg Hullender]

I found this paper, "When is it Worth Assembling Observatories in Space?" (R. Mukherjee, 2020). It suggests that in-orbit assembly of very large space telescopes may be feasible in the next decade or so.

[Lee Jay]

The argument for how starlink hurts terrestrial telescopes is weak. For any ground location, at any given time there are only 4-9 Starlinks within line of sight above about 30 degrees of the horizon.

And the plan is to increase that by a factor of 10, plus add the satellites from the other planned and ongoing constellations.

[Lee Jay]

People used to say the whole “don’t kid yourself” line about megaconstellations (“Teledesic failed! Just not viable.”) And then Starlink/OneWeb happened.

Patronizing defeatism.

Remember what I said that about:  "And don't kid yourself.  Telescopes like the Subaru, VLT, GMT and EELT aren't going to space anytime soon."

Show me a large scope (8m or larger) that's funded and when it's going to space.

Show me a reason to be concerned about the full Starlink v2 constellation after it has already launched… same silly argument.

Because V2 isn't funded and planned?

[su27k]

Note a lot of big telescope and instruments will be fine even with tens of thousands of satellites, as this figure from the paper "Analytical simulations of the effect of satellite constellations on optical and near-infrared observations" shows: even for 60k satellites, a lot of telescope and instruments will have less than 1% losses.

So there's no need to replace every big telescope on Earth in the short term, just replacing the few most affected would be sufficient to make the impact neglectable.

[Robotbeat]

People used to say the whole “don’t kid yourself” line about megaconstellations (“Teledesic failed! Just not viable.”) And then Starlink/OneWeb happened.

Patronizing defeatism.

Remember what I said that about:  "And don't kid yourself.  Telescopes like the Subaru, VLT, GMT and EELT aren't going to space anytime soon."

Show me a large scope (8m or larger) that's funded and when it's going to space.

Show me a reason to be concerned about the full Starlink v2 constellation after it has already launched… same silly argument.

Because V2 isn't funded and planned?

Will they fund and plan a space telescope that relies on Starship before Starship has demonstrated it exists, is reliable, and is affordable by launching a bunch of V2 satellites? Of course not.

So yours is kind of a silly standard. You won't acknowledge the real possibility of Starship's capability ("don't kid yourself") but you will fearmonger about ...the consequences of Starship's capability.

Trying to have it both ways.

[libra]

Big space telescopes are perfectly feasible if Starship works.

ENOUGH IS ENOUGH, I CAN'T TAKE THE SILINESS ANYMORE.

Pony and unicorms are perfectly feasible if Starship works.

Seriously: this thread show perfectly what's wrong with SpaceX amazing peoplem cranked to 11. The level of obtuse reasonning and magical thinking has reached new heights.

Also complacency and arrogance. 

We should strap a bunch of BFR-Starship to EELT in Chile and send it in orbit.

I'm sickened, really. Some people really have delusion of grandeurs and live in a magical world.

What happened to this forum over the last ten years ?

Bottom line: ends justify means. Precious genius Elon Musk needs Starlink to fund his Mars plan and fill his big rockets.

According to that: SCREW astronomy.

Astronomers are stupid, they keep building ground based telescopes when Musk is littering the sky with Starlink. Stupid astronomers, get away, and put your stupid telescopes in orbit, with Magic Starship ! And if you don't want to do, Elon Musk and his amazing people graciously tell you to go to hell

[eeergo]

Big space telescopes are perfectly feasible if Starship works.

ENOUGH IS ENOUGH, I CAN'T TAKE THE SILINESS ANYMORE.

Pony and unicorms are perfectly feasible if Starship works.

Seriously: this thread show perfectly what's wrong with SpaceX amazing peoplem cranked to 11. The level of obtuse reasonning and magical thinking has reached new heights.

Also complacency and arrogance. 

We should strap a bunch of BFR-Starship to EELT in Chile and send it in orbit.

I'm sickened, really. Some people really have delusion of grandeurs and live in a magical world.

What happened to this forum over the last ten years ?

Bottom line: ends justify means. Precious genius Elon Musk needs Starlink to fund his Mars plan and fill his big rockets.

According to that: SCREW astronomy.

Astronomers are stupid, they keep building ground based telescopes when Musk is littering the sky with Starlink. Stupid astronomers, get away, and put your stupid telescopes in orbit, with Magic Starship ! And if you don't want to do, Elon Musk and his amazing people graciously tell you to go to hell

This.

Same magical thinking that gave tunnel vision to those that staunchly believed STS to be a "shuttle" to space for as many people and as much cargo as you could possibly want, only much earlier in the development process, thanks to unwavering faith in a persona.

Don't forget the new argument: any interference or inconvenience to megaconstellations is unacceptable, nothing to do with interference to astronomy, which is trivial -or even beneficial: just throw your inexpensive huge telescope to space and give up Earthen limitations! Anyone who says otherwise is a liar, those professionals who oppose megaconstellations' unbridled development luddites, pundits or just trolls, or just don't exist, can't tell by now.

[daedalus1]

Low earth orbit was always destined to become more and more crowded from the launch of Sputnik 1. It was inevitable whether Musk happened or not. Ground astronomy will have to find a coexistence based on that fact.

[Greg Hullender]

Note a lot of big telescope and instruments will be fine even with tens of thousands of satellites, as this figure from the paper "Analytical simulations of the effect of satellite constellations on optical and near-infrared observations" shows: even for 60k satellites, a lot of telescope and instruments will have less than 1% losses.

So there's no need to replace every big telescope on Earth in the short term, just replacing the few most affected would be sufficient to make the impact neglectable.

This point deserves more discussion. The trouble with satellite trails is the impact they have on large-aperture telescopes. Other telescopes are largely unaffected. Some of those telescopes can minimize the impact in various ways, and SpaceX can help by making the satellites themselves less reflective. When all possible mitigation is taken into account, what is the actual impact on astronomy?

Add to that the fact that there is a big advantage to putting telescopes in space, albeit at higher price, and, as the article I cited above points out, we should be able to assemble orbital telescopes of almost arbitrary size, if we want to. So there should be a net gain in function from putting a telescope like the Vera Rubin in orbit, which ought to soften the cost impact at least a little.

[Robotbeat]

Big space telescopes are perfectly feasible if Starship works.

ENOUGH IS ENOUGH, I CAN'T TAKE THE SILINESS ANYMORE.

Pony and unicorms are perfectly feasible if Starship works.

Seriously: this thread show perfectly what's wrong with SpaceX amazing peoplem cranked to 11. The level of obtuse reasonning and magical thinking has reached new heights.

Also complacency and arrogance. 

We should strap a bunch of BFR-Starship to EELT in Chile and send it in orbit.

I'm sickened, really. Some people really have delusion of grandeurs and live in a magical world.

What happened to this forum over the last ten years ?

Bottom line: ends justify means. Precious genius Elon Musk needs Starlink to fund his Mars plan and fill his big rockets.

According to that: SCREW astronomy.

Astronomers are stupid, they keep building ground based telescopes when Musk is littering the sky with Starlink. Stupid astronomers, get away, and put your stupid telescopes in orbit, with Magic Starship ! And if you don't want to do, Elon Musk and his amazing people graciously tell you to go to hell

This.

Same magical thinking that gave tunnel vision to those that staunchly believed STS to be a "shuttle" to space for as many people and as much cargo as you could possibly want, only much earlier in the development process, thanks to unwavering faith in a persona.

Don't forget the new argument: any interference or inconvenience to megaconstellations is unacceptable, nothing to do with interference to astronomy, which is trivial -or even beneficial: just throw your inexpensive huge telescope to space and give up Earthen limitations! Anyone who says otherwise is a liar, those professionals who oppose megaconstellations' unbridled development luddites, pundits or just trolls, or just don't exist, can't tell by now.

Oh please, I’m not asking for you to become a fanboi. I’m just asking for some consistency!

Either be hyper-skeptical of Starship (and the idea you can inexpensively make lots of high quality aerospace hardware to fill its payload bay) or don’t.

You can’t have it both ways, so make up your mind!

I think it’s perfectly rational for astronomers to be skeptical of Starship launching big cheap telescopes. But one must also be skeptical that SpaceX can launch Starship cheaply enough, with cheap enough spacecraft, to fill out Starlink v2 as they claim.

Please: Make. Up. Your. Minds.

(Astronomy is awesome, and quit putting slanderous words in my mouth. I love astronomy.)