Author Topic: SpaceX F9 : Starlink v1.0 L19 : CCSFS SLC-40 : 15/16 Feb 2021 (0359 UTC)  (Read 91079 times)


Offline wannamoonbase

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Entry burn shutdown did not look nominal?

No it did not and the 'fire' from the engines seems to go on past the normal shut down.  Then the telemetry stopped.

The loss of this booster will hinder Starlink deployment.  So maybe those FH side boosters need to be queued up.

Rockets are hard.
Superheavy + Starship the final push to launch commit!

Offline HVM

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This mission vs. last; seconds after entry burn shut down:
« Last Edit: 02/16/2021 03:20 am by HVM »

Offline Jansen

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Starlink mission is still nominal. Deployment is still on schedule for T+01:04:28.

Next event at T+45 mins.
« Last Edit: 02/16/2021 03:23 am by Jansen »

Offline HVM

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Thanks to the telemetry from this launch and last launch we can tell that the entry burn shut off speed and altitude is near identical. Yet there was a lot more plasma.
But Starlink 18 telemetry continued to the landing, now it cut out same time as video link...

Offline Nevyn72

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Thanks to the telemetry from this launch and last launch we can tell that the entry burn shut off speed and altitude is near identical. Yet there was a lot more plasma.
But Starlink 18 telemetry continued to the landing, now it cut out same time as video link...
That's because the Starlink 18 booster was still intact/functional.

Offline Exastro

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Uninformed speculation: Off-center plasma is due to incorrect attitude.  The grid fins deployed but didn't seem to be moving after that.  Perhaps another hydraulic pump failure?

Online pb2000

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Uninformed speculation: Off-center plasma is due to incorrect attitude.  The grid fins deployed but didn't seem to be moving after that.  Perhaps another hydraulic pump failure?
They are still using RCS at that altitude, so even if they do move the grid fins don't accomplish much.
Launches attended: Worldview-4 (Atlas V 401), Iridium NEXT Flight 1 (Falcon 9 FT), PAZ+Starlink (Falcon 9 FT), Arabsat-6A (Falcon Heavy)
Pilgrimaged to: Boca Chica (09/19 & 01/22)

Offline kdhilliard

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Uninformed speculation: Off-center plasma is due to incorrect attitude.  The grid fins deployed but didn't seem to be moving after that.  Perhaps another hydraulic pump failure?
They are still using RCS at that altitude, so even if they do move the grid fins don't accomplish much.
Plus you can see the plasma-back-lit grid fin on the right move back and forth a bit after entry burn shutdown.

Online pb2000

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SES-2 ignition
Good oribt
« Last Edit: 02/16/2021 03:46 am by pb2000 »
Launches attended: Worldview-4 (Atlas V 401), Iridium NEXT Flight 1 (Falcon 9 FT), PAZ+Starlink (Falcon 9 FT), Arabsat-6A (Falcon Heavy)
Pilgrimaged to: Boca Chica (09/19 & 01/22)

Offline Jansen

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MVac burn successful, nominal orbit insertion
« Last Edit: 02/16/2021 03:48 am by Jansen »

Offline RotoSequence

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Just two days short of a year since booster 1056 was lost.

Offline Jansen

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Deployment successful
« Last Edit: 02/16/2021 04:09 am by Jansen »


Offline AndrewRG10

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https://twitter.com/elonmusk/status/1361544540411355137

Quote
Yeah. Active fairing half recovered though.

Sounds like good fairing splash down and Elon acknowledges landing failure, a lot better than the weeks it took for B1056 and 11 months (and counting) for B1048.

Offline AC in NC

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Staged at about 7900 km/h and 67 km
Topped out at 7100 km/h and 115km.
Velocity drifted up to 8066 km/h at entry burn @ 55.1 km 
Entry burn dropped that to 5750 km/h @ 35.7 km.
Only picked up 6 km/h before the reorientation took hold.
And bled enormous velocity all the way to the landing burn.


Staged at about 7870 km/h and 68.4 km
Topped out at 7075 km/h and 116km.
Velocity drifted up to 8063 km/h @ 55.2 km at entry burn   
Entry burn dropped that to 5875 km/h @ 31.7 km (T+6:51)
Extra burn dropped that to 5365 km/h @ 22.3 km (T+7:02) when frame froze
Telemetry froze at 5241 km/hr @ T+7:04


Comparing the phases of this and last Stage 1 telemetry.  Very similar until thing went awry except that the nominal portion of the entry burn seemed to take S1 to 4km lower than before.

Offline Jansen

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Offline yokem55

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Staged at about 7900 km/h and 67 km
Topped out at 7100 km/h and 115km.
Velocity drifted up to 8066 km/h at entry burn @ 55.1 km 
Entry burn dropped that to 5750 km/h @ 35.7 km.
Only picked up 6 km/h before the reorientation took hold.
And bled enormous velocity all the way to the landing burn.


Staged at about 7870 km/h and 68.4 km
Topped out at 7075 km/h and 116km.
Velocity drifted up to 8063 km/h @ 55.2 km at entry burn   
Entry burn dropped that to 5875 km/h @ 31.7 km (T+6:51)
Extra burn dropped that to 5365 km/h @ 22.3 km (T+7:02) when frame froze
Telemetry froze at 5241 km/hr @ T+7:04


Comparing the phases of this and last Stage 1 telemetry.  Very similar until thing went awry except that the nominal portion of the entry burn seemed to take S1 to 4km lower than before.

The entry burn was ~125 km/hr short of the previous 'nominal' burn. Not sure if that was within norms, but it could indicate a slight underperformance.

Offline vaporcobra

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Just to add to AC in NC's analysis, there was a big gap between real callouts and SpaceX's online timeline from MECO through SES1, SECO, SES2, and deploy. Started at ~5 seconds behind and grew to 10, 20, and eventually ~30 seconds behind at Starlink deploy.

It's somewhat reminiscent of the Starlink-5 engine-out scenario, which also saw the real-time events depart from SpaceX's official timeline, except there was no evidence of an engine shutdown and S1 telemetry implies that B1059 made it through a full reentry burn.

Offline OneSpeed

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Here is a comparison of the S1 telemetry from Starlink L18 and L19.

1. The result of the boost phase is identical in terms of velocity and altitude gained.
2. The L19 entry burn acceleration reduces by about a quarter from 399-401s, and continues at that level until MECO2 at 405s.
3. This difference may well correspond with a single early engine shutdown.

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