How satellite ‘megaconstellations’ will photobomb astronomy images • Hacker News Board

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#371

Post by gorgoiler » Fri, Aug 28, 2020, 6:02 AM UTC

gambiting wrote: post #63

dr_dshiv wrote: post #49

Earlier quoted context omitted.

I'm sure astronomers would pay for access to a global distributed space-based telescope. So, if there is demand... We are about to have a huge supply.

I often wonder how come we(as in, humanity) ever only launched a single Hubble telescope. Surely, once you built one, you should be able to build more. Or other countries should be able to take the designs and launch their own versions. Hubble was(and I imagine still is) occupied for weeks at the time taking pictures of certain areas of the sky. Why don't we have 50 Hubbles up in the orbit, doing different things sim…

It’s a great point — how much would it add to the cost of these projects to convert them into assembly lines?

Separately, I was surprised to learn how many observatories there are in space. Here’s just a selection:

https://commons.m.wikimedia.org/wiki/File:Space_telescopes.j...

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#372

Post by acqq » Fri, Aug 28, 2020, 6:05 AM UTC

m4rtink wrote: post #289

acqq wrote: post #123

Earlier quoted context omitted.

> Is that true? Absolutely. > What are they missing? Everything. Whatever one can do on Earth which requires big optics and maintenance is many millions times more expensive to do in the orbit. And the many million times higher expenses of all astronomical projects in the world are certainly not going to be covered by the operators of the "cheap and small" satellites. Optics, for the purposes we talk about, just does…

Isn't the mess that is JWST caused not only by cost plus contracts but also having to put the whole thing on top of an Ariane 5 ? Putting it into a 9 meter diameter Starship, possibly in multiple pieces that would be assembled and periodically serviced by crew flights would make it all much easier, cheaper and more performant.

> possibly in multiple pieces that would be assembled and periodically serviced by crew flights would make it all much easier, cheaper and more performant.

Again, wrong belief, again like I mentioned before, in the style "ha ha we can send ants for them too" (answer: no we can't), see FAQ:

https://jwst.nasa.gov/content/about/faqs/faq.html#serviceabl...

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#373

Post by gorgoiler » Fri, Aug 28, 2020, 6:08 AM UTC

shajznnckfke wrote: post #286

HumblyTossed wrote: post #274

Earlier quoted context omitted.

> Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three companies from one country. Not to mention there will be far fewer non-processed photos. Most people won't care, but it just seems like nothing we see anymore is real.

In between the thing and your perception of it, there are so many layers of bending, stretching, reflection, quantization, imputation, and filtering, occurring through different physical, digital, and biological processes. Why does this one make the image not real?

Processes that are agnostic of the image and its artifacts feel different — “acceptable” — compared to ones that are specific to the image content itself.

I am now imagining a science fiction story where visitors to Earth initiate communication with us using faint arcs of light across the night sky. No one notices and the telescopes and cameras filter them all out. The visitors go home, sulking.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#374

Post by simion314 » Fri, Aug 28, 2020, 6:39 AM UTC

TeMPOraL wrote: post #345

welterde wrote: post #244

Earlier quoted context omitted.

You are forgetting that the telescope has to work in space. Big thermal swings, no easy air cooling, no AC outlet to get your power from, no convenient anchoring point for your telescope to push against to point a certain direction, no just bolting several racks full of off-the-shelve electronics to the telescope (none of them work in vacuum), no possibility to repair or upgrade anything, ... Having to use lightweigh…

With much cheaper launch costs, you can afford to send a couple more robust telescopes. That's the vicious cycle of space mission costs put in reverse. The missions are expensive today, because launches are expensive, meaning you have one shot at doing your decade-long project, so you need to max out on risk mitigation - increasing your project length, labor costs, and launch mass. Significant drops in launch costs a…

>The missions are expensive today, because launches are expensive

I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky.

There are many existing communication and navigation satellites but not that many space telescopes so I think this proves that launching shit is not prohibitive expensive but I will read any claim that proves you right.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#375

Post by guerrilla » Fri, Aug 28, 2020, 7:02 AM UTC

gpm wrote: post #329

guerrilla wrote: post #43

Earlier quoted context omitted.

> will cost you some effort and money and time. This externality needs to be captured for it to be fair.

This is a curious assumption. Why would the small number of astronomers get ownership over the resource of the night sky instead of the much larger population of people who want internet? I'd argue that the positive externalities of the latter far outweigh the negative externalities of the former when deciding how to tax spacex.

> Why would the small number of astronomers get ownership over the resource of the night sky instead of the much larger population of people who want internet?

They would not. It belongs to the whole of the population, not any part of it. Depriving any part of the population, especially without consent, is what's unfair and requires compensation.

> I'd argue that the positive externalities of the latter far outweigh the negative externalities of the former when deciding how to tax spacex.

This sounds like a great way to introduce abitraryness into the situation. If it has a value to all these parties then it has a price and if people are going to deprive other people of that then they can pay for those people's loss, and even better, get everyone's consent instead of making assumptions about the greater good and collective good.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#376

Post by verytrivial » Fri, Aug 28, 2020, 7:11 AM UTC

reitzensteinm wrote: post #42

verytrivial wrote: post #15

The article covers the mitigations already in place and how they only partially resolve the issue. These satellites are low, bright (at dawn/dusk) and very soon to be incredibly numerous. Yes, it is possible for data workflows to post-process these streaks away, but not all configurations allow this, and whereas previous intrusions were somewhat rare and could be ignored that simply won't be the case due to three com…

I personally believe that pervasive high speed internet even in remote locations will do more for humanity than the scientific cost of these satellites. However, this conversation has basically been skipped over. Maybe you're right and I'm wrong. The constellations are being launched, and there's zero chance of shutting them down once they're serving a commercial role. Considering the abundant red tape in the modern…

You are might be right (though we could quibble over diminishing returns on speed over a few Mbps). But you seem to be discussing this as a choice.

One nation launching thousands of satellites because three companies want to make a pile of money and also because that one country can't get it's act together and do something about its own predatory cable companies seems like a weak argument to make from a moral point of view.

But what about third world countries and such? Summary opinion: The people who could afford Starlink already have broadband, and we wouldn't want to subsidize others access, would we? That path leads to socialism and the USPS. Or indeed broadband as a right attached to cable company's license. Impossible! (In that one country.)

Let third world countries sort out their own broadband and make their own money. And let them have their own view of the damn stars.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#377

Post by TeMPOraL » Fri, Aug 28, 2020, 7:50 AM UTC

simion314 wrote: post #374

TeMPOraL wrote: post #345

Earlier quoted context omitted.

With much cheaper launch costs, you can afford to send a couple more robust telescopes. That's the vicious cycle of space mission costs put in reverse. The missions are expensive today, because launches are expensive, meaning you have one shot at doing your decade-long project, so you need to max out on risk mitigation - increasing your project length, labor costs, and launch mass. Significant drops in launch costs a…

>The missions are expensive today, because launches are expensive I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky. There are many existing communication and navigation satellites but not that many space telescopes so I think this proves that launching shit…

> I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky.

Radhard stuff is expensive, but not that expensive. Also space missions don't need all that much compute - they carry only as much as is needed to operate the hardware and maintain a radio link with Earth. You don't use more than you absolutely need to, because more compute = more power demands = more waste heat => need more thermal management => heavier satellite => need to cut down mass (or power demands) somewhere else => ballooning R&D costs => ...

Look, I'm not making this up. It's widely known in the industry. See e.g. [0] and [1] for the first two references I could find. I actually learned about this concept from some NASA report that featured a beautiful flowchart, but I can't find it now for the life of me. But the phenomenon is real, and that's why SpaceX has been a big deal in space circles for years now. More and cheaper launches translate to a qualitative difference in how we approach space systems.

> There are many existing communication and navigation satellites but not that many space telescopes so I think this proves that launching shit is not prohibitive expensive

Communication satellites pay back for themselves in rent the owners can extract from the users. Navigation satellites are first and foremost military projects with huge implications for national security of the states that own them - which gives them almost infinite budgets. Space telescopes are research platforms funded by taxpayers, most of whom don't understand the importance and don't care to. Astronomy can't afford space telescopes at current prices.

--

[0] - https://www.thespacereview.com/article/1121/1

[1] - https://www.thespacereview.com/article/1918/1

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#378

Post by iso1210 » Fri, Aug 28, 2020, 9:02 AM UTC

simion314 wrote: post #254

iso1210 wrote: post #177

Earlier quoted context omitted.

More like "you build something ugly opposite my house"

Disagree, if I make a factory in China that generates some ugly clouds so you can't see your beautiful sky anymore, then if you complain I give you a discount on my airlines so you can fly above the clouds and see the sky for the first time. It could happen if we let companies pollute for free.

I have a view over the ocean. Along comes Shell and builds an oil rig, thus spoiling my view.

I have a view over the ocean, 50 miles up the coast in another country a marina opens, and dozens of sailing ships start arriving over the hour.

I have a view, and an airport opens down the road, I'm now under a flight path, not only is my view obscured, I'm getting noise too.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#379

Post by welterde » Fri, Aug 28, 2020, 9:52 AM UTC

TeMPOraL wrote: post #345

welterde wrote: post #244

Earlier quoted context omitted.

You are forgetting that the telescope has to work in space. Big thermal swings, no easy air cooling, no AC outlet to get your power from, no convenient anchoring point for your telescope to push against to point a certain direction, no just bolting several racks full of off-the-shelve electronics to the telescope (none of them work in vacuum), no possibility to repair or upgrade anything, ... Having to use lightweigh…

With much cheaper launch costs, you can afford to send a couple more robust telescopes. That's the vicious cycle of space mission costs put in reverse. The missions are expensive today, because launches are expensive, meaning you have one shot at doing your decade-long project, so you need to max out on risk mitigation - increasing your project length, labor costs, and launch mass. Significant drops in launch costs a…

> Nobody is, nor was, sending the equivalent of a ground telescope installation upwell. You only send the looking part, with a downlink bolted on them. You do control and data processing planetside.

That rack full of electronics is the looking part (temperature controllers, power supplies, CCD controllers, motor controllers, ...). The data processing happens in a server rack on the other side of the planet in either case (ground-based or space-based).

And you somehow are under the impression that telescopes and instruments are so cheap that it doesn't matter if we loose one every year and then just launch another one. If that were the case we would be building dozens of 3m+ telescopes all over the planet every year - but we are not, because we don't have the money to do that.

Telescopes are multi-decade investments by the institutes, so even with free (free!) launches exactly as much testing will be done as before, because we can still only afford one shot.

Re: How satellite ‘megaconstellations’ will photobomb astronomy images

#380

Post by simion314 » Fri, Aug 28, 2020, 11:58 AM UTC

TeMPOraL wrote: post #377

simion314 wrote: post #374

Earlier quoted context omitted.

>The missions are expensive today, because launches are expensive I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky. There are many existing communication and navigation satellites but not that many space telescopes so I think this proves that launching shit…

> I do not believe that. The hardware and software is expensive because regular stuff will fail in space and you can't call some guy to just go and replace parts. I know it was done but it was expensive and risky. Radhard stuff is expensive, but not that expensive. Also space missions don't need all that much compute - they carry only as much as is needed to operate the hardware and maintain a radio link with Earth.…

You can't launch a 40m diameter telescope and so you would need to launch more smaller ones, then you would need to physically connect them so they are perfectly sync(can't be done in software or with imperfect distance/teime measurements). You also need all the optical and mechanical stuff to survive the launch, the difference of tempreture and pressure from getting moved from the ground to space etc.

What I am saying if Elon or Jeff makes a telescope work harder or impossible they should pay for fixing the issue not the public and it should be fixed today not in 50 years. Also a tax on opoluttion would make the management at SpaceX considering using different paints(or doing more with less) in before the satellite is designed and not after bad PR.

IMO you did not convince me that the reason we don't have tons of space telescopes is the launch price.

IMO we will probably need to have a few bases on the Moon and build telescopes there to get around the light pollution.