SpaceX F9 - Starlink Group 6-1 - SLC-40

Moderator error - Ignore this first post

 

[bxr140]

Looks like all of them are out of commission, only two or four are able to use thrusters for deorbit.

I'd speculate that they're actively deorbiting two (or maybe four?) and then to varying degrees passively deorbiting the rest, with likely a couple different attitudes to quantify drag.

 

[HVM]

Starlink-30038 and Starlink-30058 have paused the deorbit, and are now back at the deploy orbit:

 

[scaesare]

So the whole batch aren't falling out of the sky?

The altitude trajectory charts/info are new to me...

 

[HVM]

No, all of them are going down. Here is what graph should look like, green lines are tension rods (time scale is longer, but idea is same):

And here is today’s graph. Sats in the red circle look dead and are in random attitudes, decay depends where solar panels are pointing → different drag, greens are deorbiting. (I added the Reds and Greens, and are not in the original graph Index of /space/con/star)

 

[ecarfan]

So a possible explanation is that all of the new argon Hall Effect thrusters have failed. If true, this must be a big disappointment for Starlink. Whatever the cause, this is a costly failure.

 

[scaesare]

Wow... that is significant...

That one sat in the green circle that bounced back up a bit... prehaps a thruster that fired briefly?

 

[Grendal]

So a possible explanation is that all of the new argon Hall Effect thrusters have failed. If true, this must be a big disappointment for Starlink. Whatever the cause, this is a costly failure.

Those satellites were at orbital speed. They wouldn't de-orbit unless SpaceX wanted it to happen. It is possibly because there was an issue with the Hall Effect thrusters but it could be something to do with some other aspect of the satellite.

 

[HVM]

Satellites are deployed at low orbit where atmospheric drag is quite high, example tie rods come down less than a month. Also actual astronomer (Who's site these graphs are from) says that it looks like natural decay:

https://twitter.com/i/web/status/1636441355248386063

But also that ~70km more height means, it takes several months before natural deorbit:

https://twitter.com/i/web/status/1637952660866252803

New scale make graph looks less bad but don't change much:

 

[HVM]

And, yes. Starlink-30038 and Starlink-30058 have stabilized their orbit near 365km.

 

[scaesare]

So if they have stabilized at that orbit, and the rest of the batch are heading that direction... is it possible that an orbit at 365km is the intended destination? Wikipeida says:

Overall, SpaceX had requested approval for as many as 29,988 Gen2 satellites ... ~20,000 in 340–360 km shells

Perhaps the first two were a test of the new thruster capability? Would there be any reason to launch higher and then bring them down? Some sort of contingency plan if the thrusters didn't perform?

 

[mongo]

Deorbiting some, testing all before crossing ISS orbit.

https://twitter.com/i/web/status/1638616130356133888

 

[Grendal]

Article on this:

SpaceX experiencing problems with first upgraded Starlink V2 satellites

The first set of larger second-generation Starlink satellites is experiencing problems that could require SpaceX to deorbit at least some of them.

spacenews.com