SpaceX "Starlink" satellites possible impact on imaging - Forums

Topic starter

May 27, 2019 · Edited: May 27, 2019

Hello,

Last week, SpaceX (Elon Musk) has launched initial 60 communication test satellites
for the upcoming "Starlink" global internet network .

In it's final stage the system will comprise 12.000 operational Satellites in low earth orbit.
(LEO : couple of hundred KM above earth)

I guess most of you have experienced satellites crossings on your images, which was probably not an issue: may be one or two images per imaging session.
They could easily be removed from the imaging stack before processing.

I remember the rare Iridium Satellites flares (a bright flash, even visibly by the naked eye) , but the old IRIDIUM constellation was just a fleet of 66 Satellites.
( which are replaced now by 75 new ones)

Can we imagine the impact of a fleet of 12000 additional LEO satellites ?

... and "Starlink" might just be the beginning of an upcoming "internet from the sky" competition.

Wanni

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Frank Breslawski

May 27, 2019

Hi Wanni,

I've heard about it, too. The "CappaSigma" algorithm during the stacking process will hopefully help us in the future as well…

CS, Frank

AC1000

May 27, 2019

I caught parts of the "train" of 60 satellites in a row on 25 May 2019 with a 200 mm tele lens,
it caused a big trail, but this should only occur after launching:
https://www.astrobin.com/407220/?nc=user

Don't know what will be when there are thousands up there.
Cs Harald

Wanni

Topic starter

May 27, 2019 · Edited: May 27, 2019

Hi AC100 (Harald) ,
very interesting image.
Meantime I found this website to get visibility information for the Starlink satellites
for any given location :

http://me.cmdr2.org/starlink/

CS

Wanni

Concise

AC1000

May 27, 2019

Thank´ s for the link, Wanni.

Michael Timm

May 27, 2019

I am a bit scared too. Did you see this image?

Maciej's Starlink image

Scott

May 27, 2019

Any stacking program with rejection will pretty much eliminate the trails as long as you have at least 8 subs to work with. Anyone that has imaged the Orion Nebula will already be quite familiar with rejecting satellites. I do not think this will be as bad as people think and I will continue to image regardless.

Scott

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Andrea Alessandrelli

May 27, 2019 · Edited: May 27, 2019

I don't think that the impact is going to be tremendous on visual astronomy. What worries me most is the impact it may have on the scientific research, like Radio Astronomy for instance. Also many pictures or movies of the satellite train we saw so far were taken when the satellites were still in a low parking orbit (around 400km i think).
I also think that our dear Elon Musk is, right now, receiving a lot of negative feedback from people worried as we are and hopefully somebody will do something to make sure that the sky pollution will be reduced to the minimum possible. I mean you cannot just launch 12000 reflective objects into space and hope that nobody will say or do anything to change your plans or even stop you.
Still I don't understand were's the point in launching a belt of satellites in LEO at 500km when you can launch a few satellites at Geosynchronous orbit (35,786 km) and still cover the entire globe. My guess is communication lag but in my opinion this doesn't justify the extent of this operation.

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Wanni

Topic starter

May 27, 2019 · Edited: May 27, 2019

Andrea Alessandrelli:
I don't think that the impact is going to be tremendous on visual astronomy

According to the Starlink publications, the inter- satellite communication will be based on laser-links.

Well Written

TimothyTim

May 28, 2019

We’ve used Geo-sync internet sats for years since the 90s (at least from my memory), they are absolutely horrible and really useless. The latency, and bandwidth available makes them impossible for current application. The data I read about Starlink capacity, latency sound promising… 10-20ms and ability to push 20Gbps per pod… still I hope the impact on astronomy is limited.

Fluorine Zhu

May 28, 2019 · Edited: May 28, 2019

I worry about that if each picture has satellite traces, the rejection algorithm is useless. This is not a good news.

Fluorine Z.

Andrea Alessandrelli

May 28, 2019 · Edited: May 28, 2019

Fluorine Zhu:
I worry about that if each picture has satellite traces, the rejection algorithm is useless. This is not a good news. Fluorine Z.

I don't think so, at least not for now. Within the 2020 the satellites should be 720, the first deployment is of 1584 satellites so they will probably finish the 1st batch in 2022 approx. These satellites will be deployed in 40 different orbital planes and you will be affected only by the ones with an orbital inclination above your latitude. They pass over you once every a bit less than 24 hours and yet this doesn't mean that they will pass over you during the night or in the area of the sky of your interest.

Considering that SpaceX uses Cape Canaveral for launches all satellites will be put in an inclination between 28 and 90 degrees unless they plan to change inclination once in orbit (unlikely, is a very expensive maneuver in terms of fuel)

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