StaaaaaarrrrrgggghhhhhhLink...

[Zakalwe]

50 minutes ago, PhotoGav said:

That's an interesting angle on this.

Just to broaden the discussion - do you think that Man is going to be able to 'planet hop' within our solar system successfully and on a 'beyond a tourist visa' basis? The next star system is unknown and too far away for quite some time to come yet, I would imagine. Is Mars really the answer for Homo Sapiens? Bearing in mind that Mars is just as likely to be struck by some random piece of rock. In fact, I would imagine that it is actually far more likely to be struck by rocks, given its lack of atmosphere and proximity to the asteroid belt. I can see that it doubles the chance of survival, given that if one goes we have a back-up to rely on.

This is such a fascinating area of astronomy / space travel / ethics / philosophy / technology!

I think that it's only a matter of time. We are an exploring species, so it's in our make-up. Mars has loads of challenges, but ultimately there's nothing in physics to stop us, so the problems (and they are big problems) are ultimately engineering problems. We can overcome these. It was less than a century and a half ago that people thought that inhabiting the west coast of America was nigh on impossible. The journey was impossibly long, dangerous, expensive and a one-way ticket. Yet people did it.

Part of me wants them to go to the Moon again, but then again, the Delta V needed to go to Mars is not much greater than that needed to go the Mars.

[cuivenion]

5 hours ago, Zakalwe said:

Strictly speaking, the motivation is to provide funding to make Man an interplanetary species, just in case a lump of rock from the sky wipes us out. Our species is unique and leaving it on one planet to the vagaries of some random piece of rock is too risky.

I'm comfortable with some home astronomers having their hobbies affected if that's the price.

Zakalwe you seem to be trying to make out this is just about a few complainers in bobble hats in their backyard, starlink is going to effect (ironically) near earth asteroid detection as well as other scientific endeavours.

[Paul M]

I'm more of the belief that mankind should perish on this increasingly barren rock before we get the oportunity damage any of the rest of the universe.

We are our own greatest risk. There is no escaping ourselves.

[SteveWolves]

With the worldwide resources of astronomers can someone hack into Musk's system and deorbit these things?

[DaveL59]

ideally dropping them onto all of his earth facilities so he can't easily fund or launch any more  

[Graham Darke]

Just on the topic of sigma clipping I have always found that DSS reduces but doesn't remove bright satellite trails. Cant speak for APP/ PixInsight etc.  I hope Zakalwe is right that the summer months exacerbate this issue and that in Autumn, once the Sun is far enough down this issue will be less of a problem. I guess we'll all know in a few months. I've just bought a new wide field scope recently 😬

[Paul M]

21 minutes ago, Graham Darke said:

once the Sun is far enough down this issue will be less of a problem

Indeed. Although they are boosted to higher altitude than ISS, they won't be visible much either side of sunrise and sunset and even then will have truncated paths of visibillity.

I'd like to think they are a non issue but, sure, they are spoiling a lot of images right now. Very much a 1st world problem but having said that, Starlink is a money spinner and not a gracious gift to the Developing World.

I can't help thinking that with an increasingly high density of orbital junk to track, LEO is getting almost too dangerous for manned passage.

[Zakalwe]

1 hour ago, cuivenion said:

Zakalwe you seem to be trying to make out this is just about a few complainers in bobble hats in their backyard, starlink is going to effect (ironically) near earth asteroid detection as well as other scientific endeavours.

No I'm not.  I'm well aware of the concerns. I'm also well aware that these sats are easiest to spot in precisely the conditions that we have in Summertime.  They are also easiest to spot in the days and weeks after launch when they are in their initial orbits. Once they move up to their operational orbits they are far less visible.

SpaceX are also experimenting with a number of mitigation techniques. The next launch (tonight) ill carry sats with deployable  visors to prevent sunlight from reflecting off them.

No matter where you stand on these mega constellations there is one incontestable fact and that is they are here to stay and they will grow in size. Amazon are planning a similar mega constellation. Heck, even the British government are toying with pumping £millions into buying the failed One Web company now that they've realised that we don't have the cash or wherewithal to build a UK GPS alternative (though I'll not comment on this latest B word fiasco as it's against the rules).

As these constellations are here to stay we and the professionals had better get used to them, as well as working with the owners. SpaceX are listening and as a direct result of feedback from the AAS they have introduced experiments to mitigate the impact (as above).

[Zakalwe]

35 minutes ago, Paul M said:

 

I can't help thinking that with an increasingly high density of orbital junk to track, LEO is getting almost too dangerous for manned passage.

Not  in the least.

[DaveS]

Right. back on track.

AstroArt (I'm on V7) has a very good line removal tool, just click on the end points and Filters > Cosmetic > Remove Line and it's gone. It also does a good job of Sigma Stacking provided you have enough subs. I've seen satellite breakthrough on 6 subs, but not on 18.

[Paul M]

18 minutes ago, Zakalwe said:

Not  in the least.

 

20 minutes ago, Zakalwe said:

 

SpaceX are also experimenting with a number of mitigation techniques.

Only because they were oblivious to the issue now at hand and have become worried that the following wind they are presently favourd by becoming a headwind.

It's research that should have been done in the planning stage.

18 minutes ago, Zakalwe said:

Not  in the least.

It's up there for a long time, long after the technology has been abandoned (a couple of decades?) so I don't share your confidence!

[MarkAR]

Just out of interest, anyone know what the carbon footprint of each of Musks launches are ?

If he's launching strings of 16 satellites at a time its going to be 2625 launches to get his proposed 42000 lumps into space.

[cuivenion]

36 minutes ago, Zakalwe said:

No I'm not.  I'm well aware of the concerns. I'm also well aware that these sats are easiest to spot in precisely the conditions that we have in Summertime.  They are also easiest to spot in the days and weeks after launch when they are in their initial orbits. Once they move up to their operational orbits they are far less visible.

SpaceX are also experimenting with a number of mitigation techniques. The next launch (tonight) ill carry sats with deployable  visors to prevent sunlight from reflecting off them.

No matter where you stand on these mega constellations there is one incontestable fact and that is they are here to stay and they will grow in size. Amazon are planning a similar mega constellation. Heck, even the British government are toying with pumping £millions into buying the failed One Web company now that they've realised that we don't have the cash or wherewithal to build a UK GPS alternative (though I'll not comment on this latest B word fiasco as it's against the rules).

As these constellations are here to stay we and the professionals had better get used to them, as well as working with the owners. SpaceX are listening and as a direct result of feedback from the AAS they have introduced experiments to mitigate the impact (as above).

So there is an impact that SpaceX are trying to mitigate? It's a bit strange that you've made light of issues that SpaceX themselves are trying to fix. I'd heard of earlier attempts to reduce the sats brightness that hadn't made a significant difference. The deployable visor sounds hopeful and shows that at least SpaceX are listening which is good.

The rest of the post reads as, if you don't like it, tough. I've never been a fan of that argument.

[Zakalwe]

1 hour ago, Paul M said:

 

Only because they were oblivious to the issue now at hand and have become worried that the following wind they are presently favourd by becoming a headwind.

It's research that should have been done in the planning stage.

It's up there for a long time, long after the technology has been abandoned (a couple of decades?) so I don't share your confidence!

Well, this IS the planning stage.

Regarding the second point, a bit of basic research wouldn't do any harm. The sats are in very low Earth orbit, so their orbits will decay quickly. Even if a sat dies and cannot use it's thruster then it will take about a year to de-orbit..

1 hour ago, MarkAR said:

Just out of interest, anyone know what the carbon footprint of each of Musks launches are ?

If he's launching strings of 16 satellites at a time its going to be 2625 launches to get his proposed 42000 lumps into space.

The first stage burns about 440 tonnes of RP1 (refined jet fuel). In comparison, a Jumbo jet burns about 10 tones per hour in cruise. In the great scheme of things the impact of launches is negligible. Everyday Astronaut did an excellent article a few months ago on this very subject.
When SuperHeavy flies it will burn methane and LOX in comparison to the Falcon9's RP1/LOX combination. The main reason is methane can be readily made in-situ on Mars using the Sebatier process by extracting CO2 from the atmosphere and combining it with hydrogen extracted from water electrolysis.

 

By the way, it's 60 sats per Falcon9 launch, not 16. And once SuperHeavy and Starship are operational it will be 200 sats per launch.

If environmental concerns are a big concern of yours (and rightly so, I might add), then you should really be a big fan of Musk. After all, no-one has done as much in the last decade to take fossil fuels out of transportation, via Tesla. One of his other companies, Solar City, are also doing great work in PV installations and development.

56 minutes ago, cuivenion said:

So there is an impact that SpaceX are trying to mitigate? It's a bit strange that you've made light of issues that SpaceX themselves are trying to fix. I'd heard of earlier attempts to reduce the sats brightness that hadn't made a significant difference. The deployable visor sounds hopeful and shows that at least SpaceX are listening which is good.

The rest of the post reads as, if you don't like it, tough. I've never been a fan of that argument.

Regarding your first point, I do wish you'd read what I said. I never made light of the impact.

Regarding the second point, some of the impact was known pre-launch (that's why the sats do not transmit on the frequencies used in radio astronomy. The deployable visor is one of three different mitigation strategies that are being currently tested, but this list is not exhaustive. The blackening paint made a significant reduction in brightness (though not enough to render the sat invisible). It had a knock-on impact in that it caused the sats to overheat, however. A third technique, where the sats re-orient themselves to prevent reflecting light onto the ground is also in testing.

Lastly, to address your third point "if you don't like it, tough." Again. please re-read what I have said and not what you think I said. Starlink, and other mega-constellations, are an unfortunate fact of life. The FCC have issued the necessary licences to SpaceX (and also to LeoSat, Kepler and Telesat). They do not need to ask for anyone else's permission. Now, rather than pearl-clutching and venting, we have to work with these companies to mitigate their impacts.  Jim Lowenthal,  along with a working group from the AAS, for example meet once a month with SpaceX to discuss our, as astronomers, concerns about Starlink. It's also interesting to note that SpaceX is the only company that is meeting like this with concerned professional astronomers. Talking and agreeing a plan is the way forward, not ranting about shooting sats out of the sky.

 

Anyhoo, must dash. The outrage bus is due at my stop any moment now. 😆

 

 

Edited June 26, 2020 by Zakalwe

[RT65CB-SWL]

More satellites [maybe] coming to the skies near you. This was released on BBC news earlier today...
https://www.bbc.co.uk/news/uk-politics-53192842

[Zakalwe]

12 minutes ago, Philip R said:

More satellites [maybe] coming to the skies near you. This was released on BBC news earlier today...
https://www.bbc.co.uk/news/uk-politics-53192842

We can kiss that money goodbye....

[uhb1966]

1 hour ago, MarkAR said:

Just out of interest, anyone know what the carbon footprint of each of Musks launches are ?

If he's launching strings of 16 satellites at a time its going to be 2625 launches to get his proposed 42000 lumps into space.

He'll run out of money. But the debris will remain... until they fall back to earth. I do hope they are small enough to get vaporized on reentry.

 

[cuivenion]

16 hours ago, Zakalwe said:

Well, this IS the planning stage.

Regarding the second point, a bit of basic research wouldn't do any harm. The sats are in very low Earth orbit, so their orbits will decay quickly. Even if a sat dies and cannot use it's thruster then it will take about a year to de-orbit..

The first stage burns about 440 tonnes of RP1 (refined jet fuel). In comparison, a Jumbo jet burns about 10 tones per hour in cruise. In the great scheme of things the impact of launches is negligible. Everyday Astronaut did an excellent article a few months ago on this very subject.
When SuperHeavy flies it will burn methane and LOX in comparison to the Falcon9's RP1/LOX combination. The main reason is methane can be readily made in-situ on Mars using the Sebatier process by extracting CO2 from the atmosphere and combining it with hydrogen extracted from water electrolysis.

 

By the way, it's 60 sats per Falcon9 launch, not 16. And once SuperHeavy and Starship are operational it will be 200 sats per launch.

If environmental concerns are a big concern of yours (and rightly so, I might add), then you should really be a big fan of Musk. After all, no-one has done as much in the last decade to take fossil fuels out of transportation, via Tesla. One of his other companies, Solar City, are also doing great work in PV installations and development.

Regarding your first point, I do wish you'd read what I said. I never made light of the impact.

Regarding the second point, some of the impact was known pre-launch (that's why the sats do not transmit on the frequencies used in radio astronomy. The deployable visor is one of three different mitigation strategies that are being currently tested, but this list is not exhaustive. The blackening paint made a significant reduction in brightness (though not enough to render the sat invisible). It had a knock-on impact in that it caused the sats to overheat, however. A third technique, where the sats re-orient themselves to prevent reflecting light onto the ground is also in testing.

Lastly, to address your third point "if you don't like it, tough." Again. please re-read what I have said and not what you think I said. Starlink, and other mega-constellations, are an unfortunate fact of life. The FCC have issued the necessary licences to SpaceX (and also to LeoSat, Kepler and Telesat). They do not need to ask for anyone else's permission. Now, rather than pearl-clutching and venting, we have to work with these companies to mitigate their impacts.  Jim Lowenthal,  along with a working group from the AAS, for example meet once a month with SpaceX to discuss our, as astronomers, concerns about Starlink. It's also interesting to note that SpaceX is the only company that is meeting like this with concerned professional astronomers. Talking and agreeing a plan is the way forward, not ranting about shooting sats out of the sky.

 

Anyhoo, must dash. The outrage bus is due at my stop any moment now. 😆

 

 

First point:

'You might as well complain about there being no true darkness and damn whoever put the Sun in the sky. Complaining about that wouldn't be as fashionable though.'

'Right, I'm off to throw rocks at my nearest airport....'

'I'm comfortable with some home astronomers having their hobbies affected if that's the price. '

That's making light of the issues you said you were aware of but don't acknowledge because they don't fit your argument. Refering to people as pearl clutching and venting fits that bill as well.

Second point:

I've read that the blackening paint didn't make a significant difference at all. However, If they manage to find an answer to the problem then great.

Third point:

Sorry, that still reads as; if you don't like it, tough. 'Starlink, and other mega-constellations, are an unfortunate fact of life. The FCC have issued the necessary licences to SpaceX (and also to LeoSat, Kepler and Telesat). They do not need to ask for anyone else's permission.'

'Now, rather than pearl-clutching and venting, we have to work with these companies to mitigate their impacts.'

This is where you lose me. Throughout this thread you've been suggesting that the effects of starlink on astronomical observations are no big deal, nothing to worry about, but you're also suggesting that we work with SpaceX and others to mitigate their impacts. Either the the impacts are negligible or they aren't.

 

Edited June 27, 2020 by cuivenion

[PhotoGav]

While Elon Musk may have some amazing research and development projects on the go (Crew Dragon & Falcon get my full approval!), I really don’t think that we, as astronomers, should happily accept his, and others, desire and action to fill the sky with satellites. Surely humankind can find alternative methods of supplying fast internet to barren, deserted, unpopulated areas of the Earth’s surface? Do we even need to supply internet to such areas? Are we not able to collaborate as a species on other satellite projects such as GPS - does each nation really have to launch its own constellation to provide such services?

To gawp at the majesty and mystery of the night sky is one of the greatest joys of being human. We should not accept it being obliterated. We are experiencing just the first few streaks right now. In as little as ten years time the impact of the predicted number of new satellites is terrifying.

This is without even mentioning the impact of the inevitable accidents that will occur with that much LEO traffic. We’ve all seen ‘Gravity‘, just one collision could seriously impact human space travel.

I posted my images as I am passionate about astronomy and astrophotography and am increasingly concerned about the impact of commercial space operations. I am delighted that the thread has developed in the way that it has. Thank you all for your input. It is a critical discussion to have.

Above all, let’s try to mitigate humankind’s ability to ruin its environment. We are ambassadors for the Universe. 

[Zakalwe]

Starlink will provide, certainly at first, the US with Internet access.

Gravity is a Hollywood film, and a pretty terrible one at that. It's depiction of how orbital mechanics operate was tenuous at best.

 

Cuivenon seems determined to miss my point. I'm not particularly in favour of Starlink and certainly if there was another way to achieve SpaceX's goals then I'd be in favour of it. However, on the balance, I'm happy to trade a small part of amateur astronomy to achieve those goals. I do think that the impact won't be as bad as some of the hand-wringers make out.

What I am absolutely against is the spread of disinformation and, dare I say it, fake news. This is primarily a science-based hobby discussed on a science-based board. If we can't get simple facts about orbits, reflectivity, and maths correct then the general public has no chance. Parroting nonsense about objects  in very low Earth orbits lasting for decades, or making it impossible to transverse  LEO, especially when those things can be checked in seconds doesn't bode well. We are better than that, people.

anyhoo, an interesting debate.

Edited June 27, 2020 by Zakalwe

[soundwave]

I wonder if there is a way to coat new satellites with a material that reflects light after converting it to a specific wavelength, thus we will be able to filter it out using a theoretical "Satellite Suppression Filter".

Of course, even if there's a way, I highly doubt it will be employed if it's "only" to please astrophotographers.

[PhotoGav]

The negative impact of the Starlink satellite constellation and other similar large satellite systems is far from 'fake news'. Have a look at any current professional astronomical discussion of the subject, especially the impact this is having / will have on wide field survey projects (e.g. the Vera Rubin Observatory). They are having to try and find work arounds, but there is no guarantee that these will be found or will be effective. The least that SpaceX can do is enter into a discussion. Thankfully, we astrophotographers have sigma rejection algorithms to help tidy up our pretty pictures.

I will keep watching this developing story with great interest. I will also keep telling people that the 'amazing lines of satellite clones marching across the night sky' are not amazing at all...!

[Hallingskies]

Starlink puts me in mind of Thomas Midgely’s contributions to the well-being of mankind:  a cheap and highly efficient refrigerant that just happened to wipe out the planet’s ozone layer.  Or an equally cheap and effective anti-knock agent for ICEs that has contaminated everything and everyone with lead neurotoxins.  These “advances” also had their apologists, who sneeringly dismissed any concerns as so much fashionable hand-wringing nonsense on the outrage bus.  Ditto tobacco. Plastics. Climate change.

Whilst not (as far as we know) as Earth-damaging, Musk’s solution to the strictly first world problem of Improving internet connectivity is to effectively write indelible graffiti across the night sky.  I would venture that Musk is filling the sky with satellites simply because it’s sexy and he has the ability to so: he has the sledgehammer to crack that walnut.  Are there really no better ways to achieve “better” internet access than to permanently disfigure the night sky? 

It’s not the impact upon my trivial little hobby that really bothers me.  No-one knows how that will pan out and I suspect that clever software will help to mitigate the impact of Starlink and its ilk on my silly and ultimately rather pointless astropics.

What gets my goat is the sheer arrogance of Starlink.  That a single country or corporation can fill everyone’s night sky with thousands of moving points of light and there is nothing anyone can do to stop it.  One of the many highlights of my stay in New Zealand many years ago was looking up into the velvet darkness of a truly clear, dark sky.  No man-made light or dust pollution, no aircraft lights.  Just the timeless glow of the Milky Way and the wondrous brilliance of an unspoiled cosmos as seen by generations.  Mr. Musk and his like are going to steal that from everyone on the planet.  My grandchildren will never see that sky as I did.  And that is tragic.  As terrible as climate change or coronavirus or over-population or pollution?  No.  But still terrible.

No amount of rationalising will change that.  Human life will become that tiny bit poorer thanks to Starlink.

And for what?  “Better” internet access?  Some folk may be happy with that, and think it is “progress”. 

I’m not, and I don’t.   

Edited June 27, 2020 by Hallingskies

[MarkAR]

So if all you have to do is get permission from one government agency to launch whatever you like into space, then all we need is permission to launch one satellite to "clear space debris" and problem solved. All we need is a satellite capable of nudging stuff out of orbit, we could even pay Musk to launch it.

[PhotoGav]

8 minutes ago, MarkAR said:

So if all you have to do is get permission from one government agency to launch whatever you like into space, then all we need is permission to launch one satellite to "clear space debris" and problem solved. All we need is a satellite capable of nudging stuff out of orbit, we could even pay Musk to launch it.

That’s how wars start!!