14 replies to this topic

[bigbinoman]

Check out the IDA FB page about this disturbing problem. With only 80 satellites of 7000 that reflect sunlight in the night sky we are about to lose our night skies. The FCC allowed this with no hearings. We need to write the FCC and tell them our story so they will stop further launches until they can produce a satellite that will not reflect sunlight at night.

https://consumercomp...to=/hc/requests

 

IDA= international dark skies

[Luca Artesky]

Bad news

 

Check this video from Holland

 

https://vimeo.com/338361997

[Cali]

"(Musk) also claimed that the satellites would not be visible when the stars are out and that the reason the International Space Station is visible at night is because it's big and has lights -" 

 

Sigh

 

- Cal

Edited by Cali, 29 May 2019 - 03:05 PM.

[Eddie_42]

"(Musk) also claimed that the satellites would not be visible when the stars are out and that the reason the International Space Station is visible at night is because it's big and has lights -" 

 

Sigh

 

- Cal

it is big....and has lights.   The size being the pertinent factor here.

 

Every satellite reflects sun light (glinting in the term). This got captured shortly after deployment, in a terrible glinting angle. The satellite are still spreading out around their ring, and they werent in operational configuration (panels not square to sun vector).  Neat footage, but the hysteria is overblown.  There are about 19000 tracks objects in space today (satellite, rocket bodies, debris), and 14000+ of them are in the LEO regime of orbits. How much hassle does that cause you on a nightly basis?

 

also see this thread....more hysteria..but i dont want to repeat all the counterpoints

[Chucke]

I read today that Musk has asked his engineers to design a less reflective version.  It seems the he is aware of the possible problem.

[t_image]

it is big....and has lights. ........................

I think Cali's "sigh" was the demonstration of Elon Musk's might be* complete ignorance of something basic such as it is completely impossible to resolve the light emitted by active lights on the ISS from the Earth.....Not even with the most powerful satellite tracking/imaging nation state setup in the world.

And the context was the ISS's visibility to observers naked-eye.....

Also ignorance of the ability of a shiny thing's in orbit to reflect Sunlight in the middle of the Summer night and be seen on Earth....

 

The size being the pertinent factor here.

Yes the radar cross-section, angular diameter of an object is a relatively good gauge to predict a particular object's pass reflectivity magnitude over the course of a pass,

but size doesn't completely matter.

The ISS is the size of a football field. It's flares cannot rival the predictable reflectivity of the old Iridium satellites that had antennae the size of a house door that could flare up to magnitude -8......

And orbital distance doesn't completely matter either as far as brightness. I have recorded Geostationary satellites at 35,000km (ISS=400km), that can flare up to magnitude 3....
 

 

The satellite are still spreading out around their ring, and they werent in operational configuration (panels not square to sun vector).

Given the first captures were bound to be bright. I captured them myself in the initial train with a lower horizon pass at mag. 4 max..

https://www.cloudyni...lites-on-video/

Solar panels are not the only reflective bits on a satellite, though. And there is not much definitive information publicly regarding how the Starlink satellites' operational stability and solar panel direction work. LEO satellites don't necessarily need continual panel alignment towards the Sun like Geos. The ones that do are can easily be placed in Sun-synchronous orbits where they chase the Sun across the Earth and are always in daylight. Such won't work with a communication constellation.

And 3 axis continual direction and even simpler is elaborate and expensive. If you are building an initial 1,584 out on a fast time-scale, you're not likely to add in features that would be unnecessary or add unneeded complexity.

I did capture the now quite spread-out parade of them last night as well, and one of them rivaled the brightness of Saturn (maybe slow flare)..

 

There are about 19000 tracks objects in space today (satellite, rocket bodies, debris), and 14000+ of them are in the LEO regime of orbits. How much hassle does that cause you on a nightly basis?

The "LEO regime" is a wide amount of space until MEO.

A better point to make would be this source of updated information, from your location,

https://www.heavens-...om/AllSats.aspx

that shows about 100 that will consistent pass brighter than mag 4.5 or the toggled setting....

However, that is without considering flare states of momentary glint or gradual flare that is unanticipated....

 

To consider the immediate consequences of the SpaceX venture may be a little blown out if people are calculating 12,000 new satellites at 550km all at mag. 3 (bad info on the constellation anyway),

but there is a point about momentum and the 'pandora's box' and 'genie out of the bottle' that will continue with other companies adding in their share, without regard to additional nation-states (both recognizing treaties) and also rouge ones that may as well add-in for their purposes.....

Who knows, maybe million-drone based LED lighting hovering over a city at 200 feet will be next????

 

And although it is a nice sentiment that Musk is asking his engineers to make satellites less bright,

he is required to get a large number up within a very short time table (and working) to stay in compliance with the FCC approval for the system.

And there is still the question of whether they have the ability to mass-produce the number of working satellites on a fast pace (never been done before at this scale), and whether there is funding for the complete first phase considering the other projects they have their hands in.

Remember this is not a sourced contract funded by a client or government yet....

 

At least 5 more launches in 2019. And add-in a new design for a product that needs to be mass-produced but also be the most complicated engineering challenge (build a machine that will always work without you ever being able to physically access it, survive the rigors of space and orbital forces, and make it to space functional with all the g-forces and vibrations that occur during launch.....

There is a reason companies haven't launched a lot of satellites quickly and why they are so expensive....

Both planet (~250) and Spire (~80) have launched tiny sats up for commercial purposes in the last years, but these are not as large or like the Starlink buses.. And Iridium's new fleet (Iridium Next) got up quickly with a number of launches,

but they put only 75 satellites up in a two year period. And Boeing got the build contract back in 2011. SpaceX started building in 2015..

How many do they have ready? How many can they make by then end of year? Musk is looking at 400 at least.

Can they get any with "less bright" mods up in space and be tested?

 

I don't think this is the first time smart people at SpaceX have thought about the different issues.

But I guarantee from every indicator so far, the push is speed of getting working satellites up there.

(sooner effectively operational constellation working=faster income starts rolling in, as well as ability to fund-raise investments for the rest of the project with demonstrations it will work)....

Remember SpaceX is their own launch customer, good is they don't pay another launcher. The bad is they lose tremendous income from using their vehicles to launch their own gear taking away from the opportunity for those same launch vehicles to launch other clients and get cash quick.....

The good of a nation state run program --doesn't answer to profit concerns. Bad=bureaucracy and funding.

Good of private industry=efficiency, and less bureaucracy. Bad is it answers to profit concerns.

 

And sadly, the hype will die and people will forget about 'star nerds' that won't affect the profit margin anyways...

 

Just like lighting, we are entering a whole new paradigm with space. No going back...

 

*note to Elon Musk's credit, he knows how to leverage social media and has been known to troll.

So no telling that some of his posts to raise conversation may just be good advertising and branding tactics...

We should learn by now social media fame is always good for a brand. (unless people stop buying in protest).

All publicity is good publicity....

Edited by t_image, 29 May 2019 - 08:11 PM.

[Tony Flanders]

I think Cali's "sigh" was the demonstration of Elon Musk's might be* complete ignorance of something basic such as it is completely impossible to resolve the light emitted by active lights on the ISS from the Earth

Elon Musk has many weak points -- wishful thinking being high among them. But two things that he's not are ignorant and lazy. I betcha that by now he could lecture at length about satellite visibility to an educated audience, and present a plausible-sounding (though not necessarily viable) plan for remediating it. It's a fair bet that quote got garbled by the reporter.

 

Note that the Breakthrough Starhot Initiative presupposes a satellite with 99.999% reflectivity. If that can be done, why not a satellite with 0.001% reflectivity?

 

Do I believe that either a 99.999% or 0.001% reflectivity is possible in real-life conditions? You're welcome to guess my answer!

Edited by Tony Flanders, 30 May 2019 - 06:36 AM.

[Karl Fabian]

https://www.rt.com/n...ex-astronomers/

[t_image]

Elon Musk has many weak points -- wishful thinking being high among them. But two things that he's not are ignorant and lazy. I betcha that by now he could lecture at length about satellite visibility to an educated audience, and present a plausible-sounding (though not necessarily viable) plan for remediating it. It's a fair bet that quote got garbled by the reporter.....................

No garbled by reporter necessary. It was his own Tweets! in exchange with others.

When I initially saw it I thought it was just someone with a pretend twitter account since I don't do twitter and didn't backtrack to see it was his authentic account.

Still out there:

https://twitter.com/...326965581570048

 

Even acknowledged by his corporate publishers:

"To clarify Elon's tweet: The ISS does have a few dim external lights, but they are *not* what you see from the ground. When we see the ISS with the naked eye, it is almost entirely due to it being a large object that reflects a lot of sunlight.
    — Max Fagin (@MaxFagin) May 25, 2019

SpaceX CEO Elon Musk didn’t help things by throwing inaccurate information into the mix, claiming that the ISS is visible because it “has lights” and indicating that Starlink satellites would not be visible at night (they will definitely be visible some of the time)."

https://www.teslarat...s-spark-fights/

 

So the "sigh" is valid and stands, although with my asterisks I postulated he may have intentionally thrown those as grenades to spark even more controversy just as a troll, even if he knew what he was saying wasn't true.....

 

I don't expect CEOs to be subject matter experts on everything, and I give leaders permission to say stupid things because it happens. Usually you'd want some smart handlers to help you before you throw crazy statements out there, but people get elected nowadays by trolling and leveraging twitter and social media in  counter-intuitive ways....

Edited by t_image, 30 May 2019 - 11:43 AM.

[earlyriser]

Elon Musk has many weak points -- wishful thinking being high among them. But two things that he's not are ignorant and lazy. I betcha that by now he could lecture at length about satellite visibility to an educated audience, and present a plausible-sounding (though not necessarily viable) plan for remediating it. It's a fair bet that quote got garbled by the reporter.

 

Note that the Breakthrough Starhot Initiative presupposes a satellite with 99.999% reflectivity. If that can be done, why not a satellite with 0.001% reflectivity?

 

Do I believe that either a 99.999% or 0.001% reflectivity is possible in real-life conditions? You're welcome to guess my answer!

I think the thermal load from absorbed sunlight would be problematic. Excessive cooling from efficient blackbody radiation when in the shadow of Earth might also be a problem. I believe this is the reason why spacecraft are typically shiny or painted white.

Edited by earlyriser, 31 May 2019 - 05:53 AM.

[t_image]

Thanks to the code written by Astronomy Live's youtube channel owner,

https://www.howmanys...illyoursky.com/

https://www.youtube.com/messierhunter

 

I generated TLE's for 66 satellites in 24 orbital planes at 550km to simulate the planned first shell of Starlink satellites.

I created an animation from an arbitrary location,

I chose Long Island, New York since it is near a large population.

 

This is if there were 1,584 Starlink satellites up and place right now,

each frame is a 10 minute change in time, as can be read.

 

Note the promise that you won't be able to see them deep into a summer night is not necessarily factual.

 

The satellite icons shown indicate they will be reflecting Sunlight.

However, their brightness may be in the range of mag. 4- mag 10 or dimmer, depending on time/location/orientation.

Flares are also not animated as the operational orientation is not yet known thus not making them predictable.

Expect flares to be up to mag. 1 or brighter depending on reports so far....

 

[akulapanam]

Complaints should be made to the FCC which has jursitiction over approving these.

[Cali]

Astronomy group calls for urgent action on SpaceX Starlink satellites.

 

Whatever.

 

- Cal

[t_image]

Astronomy group calls for urgent action on SpaceX Starlink satellites.

 

Whatever.

 

- Cal

uh oh,

Don't make the IAU angry.

They might take Earth's planetary status away........

[James Ball]

Looks like even Lowell Observatory has noticed them

 

http://spaceweather.com/

 

http://spaceweatherg...pload_id=153933

 

Second in case the story drops off the main page.