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A comment on Starship – SN8 – High-Altitude Flight Test. Parent comment

Re:Starship – SN8 – High-Altitude Flight Test by grishka on Wednesday December 09, 2020 @06:01PM (#25366582)
> no idea if it was supposed to be running on two, then one engine

Yeah and then something caught fire near the engines. I expected it to explode that very moment.

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Re:Starship – SN8 – High-Altitude Flight Test by oska on Thursday December 10, 2020 @12:24AM (#25370091)
> Yeah and then something caught fire near the engines.

This is an artifact of air flow vortices around the base of the rocket and its skirt and is completely normal. This video [1] explains it well.

[1] https://www.youtube.com/watch?v=yJceyvBKxc0&t=15m14s

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Re:Starship – SN8 – High-Altitude Flight Test by AnimalMuppet on Wednesday December 09, 2020 @06:10PM (#25366720)
Delayed gratification by a few minutes, but we got the pretty fireball in the end...
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Re:Starship – SN8 – High-Altitude Flight Test by Filligree on Wednesday December 09, 2020 @06:05PM (#25366636)
I think that was the ignition system; the green flame matches. Which makes sense if they lost an engine, of course.
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Re:Starship – SN8 – High-Altitude Flight Test by Gwypaas on Wednesday December 09, 2020 @06:16PM (#25366815)
The merlin engine uses TEA-TEB which causes the green flame seen on Falcon 9. The raptor uses electric spark ignition, which is harder but doesn't require any awfully poisonous chemicals and you can't run out.

https://en.wikipedia.org/wiki/SpaceX_Raptor

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Re:Starship – SN8 – High-Altitude Flight Test by grishka on Wednesday December 09, 2020 @06:43PM (#25367197)
No, not that, I meant the moment when one of the three engines shut off mid air and then moved away a bit so the remaining ones point straight down.
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Re:Starship – SN8 – High-Altitude Flight Test by remarkEon on Wednesday December 09, 2020 @06:13PM (#25366762)
What's the reason that the flame produced by the ignition system is green?

Edit: ah, it's answered here https://news.ycombinator.com/item?id=25366736

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Re:Starship – SN8 – High-Altitude Flight Test by elteto on Wednesday December 09, 2020 @06:57PM (#25367369)
That’s incorrect. Raptor does not use a TEA/TEB igniter like Falcon. It uses a spark igniter.

The green flame here is unintended engine ablation :) The chamber was melting.

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Re:Starship – SN8 – High-Altitude Flight Test by ArPDent on Wednesday December 09, 2020 @08:01PM (#25368059)
specifically it's copper being vaporized i believe
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Re:Starship – SN8 – High-Altitude Flight Test by remarkEon on Wednesday December 09, 2020 @09:13PM (#25368743)
Nice. Flashbacks to highschool chemistry. I'm assuming this isn't something you want to have happen ...
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Re:Starship – SN8 – High-Altitude Flight Test by SAI_Peregrinus on Wednesday December 09, 2020 @11:12PM (#25369613)
No, engine-rich combustion cycles are definitely not something you usually want. Especially not on a re-usable craft.
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