Starlink : On Orbit Satellite Tracking / Maneuvers

[Hummy]

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?

I believe they wrote it off and started deorbiting. On the plot below the red line is data from the SSN (space-track.org), the dark blue line is Celestrak data derived from ephemerides SpaceX shares with both the SSN and Celestrak. Ticks are data points.

My theory: SpaceX lost communications with STARLINK-1118 on day 39 but continued to post ephemerides where STARLINK-1118 is expected to be. That caused the SSN to post wrong data for three days. Then the SSN figured the ephemerides from SpaceX are bogus and switched to observational data. Meanwhile SpaceX continued to upload ephemerides where STARLINK-1118 was expected to be for three more days. On day 51 SpaceX restored communications with the satellite and started to post real ephemerides. The satellite's orbit is now decaying due to atmospheric drag.

[ZChris13]

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?

I believe they wrote it off and started deorbiting. On the plot below the red line is data from the SSN (space-track.org), the dark blue line is Celestrak data derived from ephemerides SpaceX shares with both the SSN and Celestrak. Ticks are data points.

My theory: SpaceX lost communications with STARLINK-1118 on day 39 but continued to post ephemerides where STARLINK-1118 is expected to be. That caused the SSN to post wrong data for three days. Then the SSN figured the ephemerides from SpaceX are bogus and switched to observational data. Meanwhile SpaceX continued to upload ephemerides where STARLINK-1118 was expected to be for three more days. On day 51 SpaceX restored communications with the satellite and started to post real ephemerides. The satellite's orbit is now decaying due to atmospheric drag.

Is the steeper downward line an intentional deorbit burn?

[Hummy]

Is the steeper downward line an intentional deorbit burn?

Yes.

[Hummy]

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!

Here you go. I haven't finished automating it so I don't know when I update it next time. A lot of values are guesses (deorbiting, likely broken, having issues) especially for v0.9 satellites. "Lost" means SpaceX lost communications and hasn't posted ephemerides updates for more than 30 days. "No updates" means no updates for more than 4 days. "Likely broken" are still communicating with SpaceX but my guess they are unusable. "Adjusting" means they reached the target orbit but are adjusting RAAN or position.

[meberbs]

Thanks for this, it concisely shows all of the information I would care about and a good bit that is more detail than I have been able to track. Average altitude for each grouping might help, as additional info, but there are regular updates of good altitude plots so that is less needed, the "raising/deorbitting/etc." is more useful for understanding status.

One of the most useful bits from my perspective is RRAAN. I don't think I have seen it explained well here, so for anyone wondering about deployment strategy, here is what I figure the plan is (This is not all my own idea, some tweets are what this is partially based on, I think from Jonathan McDowell.)

The current shell that is being filled out will have 72 planes*, 1 set every 5 degrees. To get to initial service they seem to be filling planes every 20 degrees, skipping 3 planes in between. 6 launches filling 18 planes will be needed for the initial capability. I would not be surprised if launch 6 and 7 break the pattern some, since at their launch rate, it likely would be faster to do something such as having launch 7 have its initial plane be what would be the 3rd plane for launch 6, since that would be faster than waiting for the last 20 of launch 6 to drift all the way there. The exact nature of what they do then depends on the strategy for the in between planes and where the v 0.9 sats end up, since they seem to be drifting slowly, with enough still working to probably provide initial capability to 2 planes.

In the future, launches for topping off or replenishing satellites may have shorter drift timelines, as the final planes are only separated by 5 degrees. My guess at future deployment pattern is that launches ~7-12 will fill in the half way in between planes, so still drifting 20 and 40 degrees, to end up with planes every 10 degrees filled. After that, the last ~dozen launches will fill in the rest, only needing the 2nd and 3rd planes to drift 10 and 20 degrees respectively. By that point, they may not go with 3 planes per launch, but also start topping off planes to the full 22 per plane, and also doing < 60 per launch with some room allocated to rideshare. Starship could potentially be available during that phase throwing a wrench into all future predictions.

*Historical note: the original plan at this altitude was for 1/3rd of the number of planes or 1 set every 15 degrees. which would have required 24 planes to have some in every plane, presumably 30 degree separation (every other in the old plan) between planes would not allow gapless coverage over a reasonable area, which is why the move to more planes allows this initial deployment pattern to start offering service sooner.

[gongora]

The rideshares could start in that launch 7-12 range.

[lukas559]

Hello
Where can I find the current location of all Starlink satellites?

[Hummy]

Hello
Where can I find the current location of all Starlink satellites?

TLEs of 293 satellites that reported position to SpaceX in the last two weeks are here: https://celestrak.com/NORAD/elements/supplemental/table.php?tleFile=starlink&title=Starlink&orbits=0&pointsPerRev=90&frame=1

TLEs of all 300 satellites (fusion of the above data with observational data) are here: https://celestrak.com/NORAD/elements/table.php?tleFile=starlink&title=Starlink%20Satellites&orbits=0&pointsPerRev=90&frame=1

If you just want to visualize click the globe icon.

[gongora]

I don't think those daily Tweets belong in this thread.  If you want to keep posting them, start another thread.

New Thread: Starlink : On Orbit Tracking - Periodic Updates

[freda]

Hello
Where can I find the current location of all Starlink satellites?

TLEs of 293 satellites that reported position to SpaceX in the last two weeks are here: https://celestrak.com/NORAD/elements/supplemental/table.php?tleFile=starlink&title=Starlink&orbits=0&pointsPerRev=90&frame=1

TLEs of all 300 satellites (fusion of the above data with observational data) are here: https://celestrak.com/NORAD/elements/table.php?tleFile=starlink&title=Starlink%20Satellites&orbits=0&pointsPerRev=90&frame=1

If you just want to visualize click the globe icon.

Agree.  I use that Celestrak link to visualize when a Starlink-train is on its way to my location (it even displays well on a mobile device).   Then, once the sats get near, I use the IOS/Android app called "Satellite AR" to give me an augmented reality view of where exactly to look in my sky (in Satellite AR make sure to select the "Starlink" collection).

Back to Satellite AR... click on the various dots, and it shows you the full orbit track.  At first it looks like there are a bunch of random stragglers, but once you click a few, you begin to see they are actually in adjacent planes.  Quite interesting.

Now... if only my sky was clear enough in the winter months to actually see anything!

[ShSch]

Here you go. I haven't finished automating it so I don't know when I update it next time. A lot of values are guesses (deorbiting, likely broken, having issues) especially for v0.9 satellites. "Lost" means SpaceX lost communications and hasn't posted ephemerides updates for more than 30 days. "No updates" means no updates for more than 4 days. "Likely broken" are still communicating with SpaceX but my guess they are unusable. "Adjusting" means they reached the target orbit but are adjusting RAAN or position.

Wow, thanks a lot! Much appreciated. This is exactly the kind of information I was looking for.

[Hummy]

The second stage from the last launch re-entered the atmosphere yesterday.

[Tommyboy]

The second stage from the last launch re-entered the atmosphere yesterday.

That seems pretty quick for a launch without a deorbit burn, or was this about expected due to skipping the circularization burn?

[Hummy]

The second stage from the last launch re-entered the atmosphere yesterday.

That seems pretty quick for a launch without a deorbit burn, or was this about expected due to skipping the circularization burn?

After the deployment the second stage performed a very short (1 second?) de-orbit burn to lower perigee from 212 to 192 km. Other than that it looks like a typical orbital decay due to atmospheric drag:

[Comga]

The second stage from the last launch re-entered the atmosphere yesterday.

That seems pretty quick for a launch without a deorbit burn, or was this about expected due to skipping the circularization burn?

The second stage from the last launch re-entered the atmosphere yesterday.

That seems pretty quick for a launch without a deorbit burn, or was this about expected due to skipping the circularization burn?

After the deployment the second stage performed a very short (1 second?) de-orbit burn to lower perigee from 212 to 192 km. Other than that it looks like a typical orbital decay due to atmospheric drag:

A simple approximation suggested that the integrated drag in the elliptical orbit is several times that in the circular orbit, even though the average altitude was greater.

Dropping the perigee by 20 km should increase the difference. (Was that a second burn or just a cold gas dump of the LOX tank?  It doesn’t take much thrust.)

I asked elsewhere if anyone knew how long it took the previous Starlink second stage to renter. However a good comparison would need to include any perigee reduction in the earlier launch.

[Hummy]

I asked elsewhere if anyone knew how long it took the previous Starlink second stage to renter.

v0.9: controlled re-entry over the Indian Ocean on the second orbit. v1.0-L1: the same.

[Hummy]

space-track.org marked STARLINK-1220 (v1.0-L4) decayed on Feb 29th. The attached screenshot is a space-track.org satcat query result. But there are no space-track.org or Celestrak TLE tracks leading even partially to re-entry. Not sure if decay data is valid.

[FutureSpaceTourist]

https://twitter.com/planet4589/status/1239402044483649537

It appears that Starlink 1224 (SSN 45211), launched on Feb 17 with the 5th Starlink launch, was deorbited on Mar 9 from a 324 x 361 km orbit.  Up until that point it was orbit raising with the rest of the Batch 5 satellites.

twitter.com/planet4589/status/1239402425586507776

This is the second Starlink to be deorbited; 298 Starlinks are currently still in orbit

https://twitter.com/planet4589/status/1239434291194585089

Correction: the deorbited sat is Starlink 1220, not Starlink 1224.

[Hummy]

Constellation status in a table.
Previous update was posted a month ago. I added altitude as asked. Green mean at the target, yellow means most in a group are parked. A lot of values are guesses (deorbiting, likely broken, having issues) especially for v0.9 satellites. "Lost" means SpaceX lost communications and hasn't posted ephemerides updates for more than 30 days. "No updates" means no updates for more than 4 days. "Likely broken" are still communicating with SpaceX but my guess they are unusable. "Adjusting" means they reached the target orbit but are adjusting RAAN or position. RRAAN means RAAN relative to v1.0-L1 plane 1. See meberbs' post for a more detailed explanation.

[ShSch]

Constellation status in a table.
Previous update was posted a month ago. I added altitude as asked. Green mean at the target, yellow means most in a group are parked. A lot of values are guesses (deorbiting, likely broken, having issues) especially for v0.9 satellites. "Lost" means SpaceX lost communications and hasn't posted ephemerides updates for more than 30 days. "No updates" means no updates for more than 4 days. "Likely broken" are still communicating with SpaceX but my guess they are unusable. "Adjusting" means they reached the target orbit but are adjusting RAAN or position. RRAAN means RAAN relative to v1.0-L1 plane 1. See meberbs' post for a more detailed explanation.

Thanks a lot for the update. I'm relieved to see that the number of problematic v1.0 satellites has decreased (6 versus 10 last month), despite 60 more of them being in orbit now. It looks like SpaceX should be able to populate 18 planes at 20 degrees apart with 18-20 satellites each after the next launch.

A small suggestion, if I might. I think it makes no sense to assign a deorbited satellite to any orbital plane. Lost satellites probably shouldn't be counted either, especially if the plane is already "green", since they are most likely going to drift and change their altitudes uncontrollably.