Author Topic: Starlink : On Orbit Satellite Tracking / Maneuvers (Read 92926 times)

meberbs · « **Reply #20 on:** 02/23/2020 11:06 pm »

Quote from: 192 on 02/23/2020 10:51 pm

This tweet is somewhat misleading, Darksat is only expected to be darker in it's operational orbit, not while orbit raising. The "final altitude" comment refers to previously launched Starlink satellites, not Darksat.

The above graphs indicate that darksat may have finished orbit raising, but if so, it only just did, and this soon after that, it may not have adjusted into operational orientation yet. The claimed brightness would be completely inconsistent with the satellites that are in operational orientation, so this is most likely the case.

envy887 · « **Reply #21 on:** 02/24/2020 02:22 pm »

Quote from: meberbs on 02/23/2020 11:06 pm

Quote from: 192 on 02/23/2020 10:51 pm
This tweet is somewhat misleading, Darksat is only expected to be darker in it's operational orbit, not while orbit raising. The "final altitude" comment refers to previously launched Starlink satellites, not Darksat.
The above graphs indicate that darksat may have finished orbit raising, but if so, it only just did, and this soon after that, it may not have adjusted into operational orientation yet. The claimed brightness would be completely inconsistent with the satellites that are in operational orientation, so this is most likely the case.

Check the IDs against Celestrak orbit data. 1130 and the 3 other bright satellites are significantly above 550 km. The 5 darker satellites are at 550+/-1 km.

There is a perfect correlation between altitude and brightness, and the only plausible interpretation is that 1130 and the other 3 aren't in their final slots yet, but are still phasing and precessing. Which means they aren't in operational attitude yet. Which means this post is meaningless other than as a confirmation that 1130 is not in operational attitude yet.

Which anyone watching Starlinks should already know from the picture because in the operational configuration none of the 9 should be anywhere near mag 2.5.

FutureSpaceTourist · « **Reply #22 on:** 02/25/2020 09:00 am »

https://twitter.com/tskelso/status/1232139857150873601

Quote

CelesTrak has TLEs for 64 more objects (60 satellites & 4 spacers) from the Starlink-5 launch of Feb 17. We already had the TLE for the FALCON 9 R/B.

Rondaz · « **Reply #23 on:** 02/26/2020 01:27 am »

Just for fun: here is a simulation of a typical set of positions for a 12000-sat three-shell Starlink constellation. (Note that not all will be illuminated, of course). See how the highest density is near the max latitude of 53 degrees.

https://twitter.com/planet4589/status/1232448033851236352

Rondaz · « **Reply #24 on:** 02/26/2020 01:28 am »

Here is a similar but antipodean plot:

https://twitter.com/planet4589/status/1232455452954263554

Rondaz · « **Reply #25 on:** 02/26/2020 01:28 am »

Number of Starlinks above horizon at any one time, versus latitude. 340 km, 550 km and 1100 km shells shown separately.

https://twitter.com/planet4589/status/1232481722689871875

Rondaz · « **Reply #26 on:** 02/26/2020 01:38 pm »

Winter is better, but still lots up at times when non-professional-astronomers are likely to be looking up. By midnight they should all be in shadow, though.

https://twitter.com/planet4589/status/1232556944910618624

Moderate latitudes are also better, but not great in summer. Here is 30 S (CTIO in Chile) in summer. Even at midnight there are 200 illuminated, although only 40 are naked-eye. This is for the full 12000 satellite constellation

https://twitter.com/planet4589/status/1232557732114333696

Rondaz · « **Reply #27 on:** 02/26/2020 01:41 pm »

Here are the plots for airmass < 2 (i.e. within 60 deg of zenith). Numbers drop to 100 illuminated sats in UK summer, all night long.

https://twitter.com/planet4589/status/1232573835255386112

Rondaz · « **Reply #28 on:** 02/27/2020 02:18 pm »

More graphs

https://twitter.com/StarlinkUpdates/status/1233044182945628161

Rondaz · « **Reply #29 on:** 03/01/2020 04:14 pm »

More graphs

https://twitter.com/StarlinkUpdates/status/1234131346316025857

Rondaz · « **Reply #30 on:** 03/01/2020 04:15 pm »

Special "all-in-one" graphs

https://twitter.com/StarlinkUpdates/status/1234139439523418113

Rondaz · « **Reply #31 on:** 03/02/2020 03:30 pm »

More graphs

https://twitter.com/StarlinkUpdates/status/1234493740577894401

Rondaz · « **Reply #32 on:** 03/03/2020 02:57 pm »

More graphs

https://twitter.com/StarlinkUpdates/status/1234856134999232521

gongora · « **Reply #33 on:** 03/03/2020 03:30 pm »

Posting a tweet that just says "more graphs" isn't terribly helpful. That StarlinkUpdates Twitter account was set up to do daily posts of those graphs. For those interested I recommend following that account on Twitter. We don't need those posts linked here every day.

ShSch · « **Reply #34 on:** 03/04/2020 12:03 am »

Quote from: Rondaz on 03/03/2020 02:57 pm

More graphs

Could someone please provide (or link to) a short summary of what things look like for Starlink at the moment. How many satellites have reached their target orbits? How many are still rising/lowering? How many seems to be dead? How many orbital planes are already populated? These graphs are great, but I seem to be not quite capable of digesting them.

Thanks!

Comga · « **Reply #35 on:** 03/04/2020 02:07 am »

Quote from: gongora on 03/03/2020 03:30 pm

Posting a tweet that just says "more graphs" isn't terribly helpful. That StarlinkUpdates Twitter account was set up to do daily posts of those graphs. For those interested I recommend following that account on Twitter. We don't need those posts linked here every day.

I disagree, and appreciate having the images of the graphs posted here.
Going on Twitter is not an acceptable option for me.
The optimum frequency for cross posting is up for debate.

ShSch: Are you looking at those “special graphs” particularly the one on the left?
It’s plotted as altitude against time, and you can see them settling in or headed for ~530 km.
There are more details than altitude, like filling different planes, different locations for crossing the Equator, and spreading out around the orbit in those planes. (Those graphs are even harder to read!)

rsdavis9 · « **Reply #36 on:** 03/04/2020 01:28 pm »

Quote from: ShSch on 03/04/2020 12:03 am

Quote from: Rondaz on 03/03/2020 02:57 pm
More graphs
Could someone please provide (or link to) a short summary of what things look like for Starlink at the moment. How many satellites have reached their target orbits? How many are still rising/lowering? How many seems to be dead? How many orbital planes are already populated? These graphs are great, but I seem to be not quite capable of digesting them.

Thanks!

I agree. I would like a summary like:

300 launched
10 dead
in process of orbit adjustment?
at operational attitude?
planes?
etc

Above is total guess...

leetdan · « **Reply #37 on:** 03/04/2020 02:31 pm »

Quote from: rsdavis9 on 03/04/2020 01:28 pm

I agree. I would like a summary like:

300 launched
10 dead
in process of orbit adjustment?
at operational attitude?
planes?
etc

Above is total guess...

Jonathan McDowell was the source of Planes vs Time graphs, but he hasn't posted one in almost a month. I think these graphs will be the most useful to visualize the filling out of the constellation as a whole. The typical orbit-raising graphs being posted get less useful as time on orbit increases.

Rondaz · « **Reply #38 on:** 03/04/2020 03:58 pm »

More graphs ( Just to continue the debate )

https://twitter.com/StarlinkUpdates/status/1235218514245492736

ZChris13 · « **Reply #39 on:** 03/04/2020 05:28 pm »

Quote from: Rondaz on 03/04/2020 03:58 pm

More graphs ( Just to continue the debate )

https://twitter.com/StarlinkUpdates/status/1235218514245492736

From Launch 2, what's that purple one doing at 300 km? 350 km is the plane phasing orbit, and there's two altitudes near 550 km that are the operational orbit and the slot-phasing orbit, but there's one satellite that's maneuvered down to 300 km and looks like it's decaying with atmospheric drag?