Starlink Thread (split from SpaceX)

[Brotoro]

We watched a group of Starlink satellites from the recent launch go over. I saw 19 objects about as bright as the Big Dipper stars that they were parading through, about 60 degrees max altitude, starting at about 8:47 PM. I couldn't see any dimmer ones in the gaps with binoculars.

Nice parade.

Edited April 29, 2020 by Brotoro

[tater]

1 hour ago, Brotoro said:

We watched a group of Starlink satellites from the recent launch go over. I saw 19 objects about as bright as the Big Dipper stars that they were parading through, about 60 degrees max altitude, starting at about 8:47 PM. I couldn't see any dimmer ones in the gaps with binoculars.

Nice parade.

Think we saw the same pass over the Sandias, was pretty spectacular.

[tater]

https://www.spacex.com/news/2020/04/28/starlink-update

 

Quote

For example, earlier this year we launched DarkSat which is an experimental satellite where we darkened the phased array and parabolic antennas designed to tackle on-station brightness. This reduced the brightness of the satellite by about 55%, as was verified by differential optical measurements comparing DarkSat to other nearby Starlink satellites. This is nearly enough of a brightness reduction to make the satellite invisible to the naked eye while on-station. However, black surfaces in space get hot and reflect some light (including in the IR spectrum), so we are moving forward with a sun visor solution instead. This avoids thermal issues due to black paint, and is expected to be darker than DarkSat since it will block all light from reaching the white diffuse antennas.

 

 

So visorsat:

 

Quote

While community understanding is critical to this problem, engineering problems are difficult to solve without specifics. The Vera C. Rubin Observatory was repeatedly flagged as the most difficult case to solve, so we've spent the last few months working very closely with a technical team there to do just that. Among other useful thoughts and discussions, the Vera Rubin team has provided a target brightness reduction which we are using to guide our engineering efforts as we iterate on brightness solutions.

 

[RCgothic]

I'm almost a little sad - these modifications sound like they'll be effective enough to prevent casual Starlink spotting altogether.

[tater]

2 hours ago, RCgothic said:

I'm almost a little sad - these modifications sound like they'll be effective enough to prevent casual Starlink spotting altogether.

They'll be visible after launch as they raise orbit for some weeks.

[Brotoro]

13 hours ago, tater said:

Think we saw the same pass over the Sandias, was pretty spectacular.

And tonight should be better. The larger group (41 satellites) is coming higher overhead...although they will be earlier (8:29 PM), so the sky will be lighter. And then the group of 19 will come by at 9:04, but they will be down at 30 degrees or so in the south.

It's interesting that they separated into two groupings like that.

Also, predictions are for clearer sky.

Edited April 29, 2020 by Brotoro

[tater]

Just now, Brotoro said:

And tonight should be better. The larger group (41 satellites) is coming higher overhead...although they will be earlier (8:29 PM), so the sky will be lighter. And then the group of 19 will come by at 9:04, but they will be down at 30 degrees or so in the south.

It's interesting that they separated into two groupings like that.

Agreed.

In a perfect world, they make them disappear once deplyedm but we get trains for some days after launch

 

[Brotoro]

Well, that was very disappointing. The big group of 40 that went high overhead at about 8:30... we only saw three of them as they each flared briefly. The sky was brighter than yesterday, but I could see the Big Dipper stars, so I should have been able to spot the Starlink satellites if they were as bright as yesterday's bunch. But just a few flares.

And the bunch of 19 that were such a bright parade yesterday... When they went past tonight at about 9:04, I was able to see several of them with binoculars, but they were way too dim to see naked eye (at least with the streetlight interfering).

It must depend a lot on the orientation of the satellites relative to the Sun. I wonder if the big group is oriented differently from the 19? And the 19 were much more backlit today, I guess.

[tater]

16 minutes ago, Brotoro said:

Well, that was very disappointing. The big group of 40 that went high overhead at about 8:30... we only saw three of them as they each flared briefly. The sky was brighter than yesterday, but I could see the Big Dipper stars, so I should have been able to spot the Starlink satellites if they were as bright as yesterday's bunch. But just a few flares.

And the bunch of 19 that were such a bright parade yesterday... When they went past tonight at about 9:04, I was able to see several of them with binoculars, but they were way too dim to see naked eye (at least with the streetlight interfering).

It must depend a lot on the orientation of the satellites relative to the Sun. I wonder if the big group is oriented differently from the 19? And the 19 were much more backlit today, I guess.

Yeah, didn't try binos, I saw a couple falres.

[kerbiloid]

1 hour ago, Brotoro said:

group of 40 that went high overhead at about 8:30... we only saw three of them

Don't worry, when/if there are 12 000 of them, you'll see 3/40*12000 = 900 of them, comparable to the stars number.

(10 years later)
"Look, mom! Why those sats are not moving? Are they alive?"
"Those are stars, they always stay at same place."
"Like GSO sats?"
"Yes, kind of".

[RCgothic]

A few Starlink updates on coverage:

So that's whole UK coverage from day 1.

Also some data-rate info:

 

Edited May 7, 2020 by RCgothic

[kerbiloid]

5gon is going to ask for money for OneWeb (and some other bankrupted space companies), to not let it get lost or get in unproper hands.

They are planning to use OneWeb sats to improve communication in Arctic.

https://translate.google.com/translate?hl=ru&sl=ru&tl=en&u=https://www.interfax.ru/world/708355

Edited May 13, 2020 by kerbiloid

[mikegarrison]

What happens when the aliens come and they use our own satellites against us? Won't it be a problem that we have so many for them to use?

 

[tater]

 

[Shpaget]

Not Starlink, but One Web (yes, the bankrupt one)...

They are applying for a modification to the licence. The new Phase two calls for 47 844 sats in total.

https://fcc.report/IBFS/SAT-MPL-20200526-00062/2379569.pdf

Quote

In Phase 1, OneWeb will decrease the maximum number of authorized satellites in the OneWeb System from 720 to 716 and undertake certain adjustments to the orbital parameters of its constellation. In Phase 2, OneWeb will increase the number of authorized satellites in the OneWeb System from 716 to 47,844 satellites and make other related changes to its orbital architecture. As explained herein, grant of the Modification Application serves the public interest.

Edit:

This might be a ploy to inflate the value of the company before the selloff.

Edited May 28, 2020 by Shpaget

[tater]

1 hour ago, Shpaget said:

This might be a ploy to inflate the value of the company before the selloff.

There is a time limit to launch 50% of the sats, too.

[Shpaget]

Sure, but the option and licence to launch have value themselves.

[mikegarrison]

1 hour ago, Shpaget said:

Sure, but the option and licence to launch have value themselves.

Potentially.

Like everything else, it's only actually as valuable as somebody else is willing to pay for it.

[wumpus]

1 hour ago, mikegarrison said:

Potentially.

Like everything else, it's only actually as valuable as somebody else is willing to pay for it.

I'm guessing they are facing bankruptcy with little else of value.

Another theory is that the management of oneweb is already to buy oneweb's asset for pennies on the dollar and try all over again.  Expect a second bankruptcy (at least) once a viable constellation is up and a third company forms out of the ashes.

Presumably they have a duty to the shareholders.  No idea if they have a duty to maximize the assets available to creditors during liquidation, because the chance of the shareholders getting anything is virtually nil.

[kerbiloid]

14 hours ago, Shpaget said:

The new Phase two calls for 47 844 sats in total.

1. The madness is contagious.

2. Are they going to order the social distancing for space objects?

3. Somebody JUST MUST implement this in KSP.

Edited May 29, 2020 by kerbiloid

[Jacke]

I'm thinking all these satellites will eventually lead to Kessler syndrome.  And the true likelihood is very low that it will provide significantly faster Internet links at a reasonable cost than those on the ground.  And before then, will seriously hurt ground base astronomy in radio, infrared, and visible light.

[YNM]

1 hour ago, Jacke said:

And before then, will seriously hurt ground base astronomy in radio, infrared, and visible light.

Yeah, reading the reports from LSST (which isn't even operational yet until 2022) is pretty concerning. Amateur astrophotography could still mitigate the issues by taking out the bad exposures; but I couldn't imagine for wide-angle surveys.

[kerbiloid]

Oceanic fishes will be main users of the global network. Because they occupy ~75% of the total area.

[wumpus]

12 hours ago, kerbiloid said:

Oceanic fishes will be main users of the global network. Because they occupy ~75% of the total area.

Reminds me how Sirius (and the competing brand at the time) suddenly added a lot of country stations after starting.  Turns out that if there's one customer interested in radio stations that aren't geographically limited it is truckers.  So along with the truckers came a lot of country stations (marketing didn't expect country listeners to be early adopters).

Don't forget oceanic drilling platforms.  I remember a player from my MMO-addicted time that one of the best players was a geologist living on an oil platform.  Tons of downtime and an internet connection.  But really, any place too far to run fiber (or even coax) is a candidate for starlink.  And far more people live in the sticks than on the ocean.

[kerbiloid]

Or they hope to have a KerbNet for 5G devices like the crewless oceanic ship, and to let a fridge in Morocco talk to a coffee machine in Canada.