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Bit OT space X satellites

Ant No
 

I've heard that space X is putting a large number of low earth orbit satellites in orbit.

That they are brighter than specified and that while they are intended to provide global broadband they will wreak havoc with Astronomy.

There's over 60 at the moment but plans for a staggering 30,000.

What do we think?

Ant

Khalid Baheyeldin
 

On Tue, Nov 19, 2019 at 08:57 PM, Ant No wrote:
I've heard that space X is putting a large number of low earth orbit satellites in orbit.

That they are brighter than specified and that while they are intended to provide global broadband they will wreak havoc with Astronomy.

There's over 60 at the moment but plans for a staggering 30,000.

What do we think?
The initial launch in May caused a train of satellites to be visible orbiting, and was photographed by amateurs.
See a video of them here.

Elon Musk acknowledged the problem and instructed his engineering team to do what is necessary to reduce the albedo (reflectivity) of the satellites.

However, the solar panels will be bright no matter what. Just like the Iridium satellites used to be.
More here.

Aisling Lightworks
 

They're relatively small satellites and don't have lights on them. For amateurs like me they won't be much of an issue as I'm already running software to remove them from my photos. Professional researchers will suffer some data loss but I hardly think It'll be "the end of astronomy as we know it" as some sensationalist headlines read. Adapt. Overcome. Time Marches on. Everything will be okay.

Howard Dutton
 

On Tue, Nov 19, 2019 at 07:00 PM, Aisling Lightworks wrote:
Adapt. Overcome. Time Marches on. Everything will be okay.
Agree. I'm an optimist and these satellites have a fairly short life-span and fairly low orbit so they won't be up there forever; and as they are continuously replaced/upgraded hopefully they will become smaller and fewer.Β  SpaceX is trying to do something extraordinary with Starship and Super Heavy, as if Falcon 9 and Falcon Heavy aren't extraordinary enough, and these satellites are being put up there to pay the bills.

BTW, my wife and I saw our first rocket launch in Florida about 8 months ago, a Falcon 9.Β  I expected it to be somewhat loud but I had no idea it would be that bright, TV just doesn't do it justice.

Drew πŸ”­πŸ“·πŸš΄β€β™‚οΈ
 

On Tue, Nov 19, 2019 at 09:03 PM, Khalid Baheyeldin wrote:
Just like the Iridium satellites used to be.
Not used to be, the old Iridium satellites are still up there. They can generate a "flash" of up to -8.0 magnitude for several seconds. You can get notified when to spot them using Heavens Above. I suggest the Android App since accurate time and location is required to see such a short event.

I hardly ever setup without seeing some space garbage flying by in the eyepiece after dusk. There is so much up there already that I think observing would already be ruined if such thinking were true. However, tracking the "train" these satellites generate might be fun.

Khalid Baheyeldin
 

On Wed, Nov 20, 2019 at 11:38 AM, Drew πŸ”­πŸ“·πŸš΄β€β™‚οΈ wrote:
Not used to be, the old Iridium satellites are still up there. They can generate a "flash" of up to -8.0 magnitude for several seconds. You can get notified when to spot them using Heavens Above. I suggest the Android App since accurate time and location is required to see such a short event.
That used to be true, but it is no longer the case.

As of the end of 2018, all the old Iridium satellites with predictable flares have been de-orbited.
The replacement satellites have a new design, and do not flare like the old ones. At least they are not predictable

Drew πŸ”­πŸ“·πŸš΄β€β™‚οΈ
 

Yes, I am somewhat out of date. There was an old de-orbit plan that was derailed when the satellites where bought for short burst global communications (such as location pinging), this was back in 2015 or so.

It isΒ  not on schedule, of course. I see the last one should have come down or will come down within days, if it already hasn't (SV97). https://catchtheiridium.com/mission/ I knew I had seen a flare scheduled on Heaven Above not too long ago. Seems like not many have seen them on their wayΒ  down.

John Scherer
 

Just finished the book Eccentric Orbits about Motorola and Iridium.Β  It a great read!

Khalid Baheyeldin
 

This article shows photos of how StarLink's satellites interfere with imaging, specially large sky surveys.

Even though the trails can be removed programmatically, that process results in data loss.