Here's all 3 raptors from #SN10 50, greenie and one I'm not sure it's #@austinbarnard45
Starships - three unique side-by-side cool clips from Mary, syncing the moment of Raptors' ignition prior to landing. @NASASpaceflight @SpaceX @BocaChicaGal youtube.com/watch?v=sDTZa-…
SN10 engine was low on thrust due (probably) to partial helium ingestion from fuel header tank. Impact of 10m/s crushed legs & part of skirt. Multiple fixes in work for SN11.
This is a tricky one given that I believe said helium pressurization was added to the CH4 header tank to mitigate what happened with SN8.That's why it's a test program, of course.
Fair point. If autogenous pressurization had been used, CH4 bubbles would most likely have reverted to liquid. Helium in header was used to prevent ullage collapse from slosh, which happened in prior flight. My fault for approving. Sounded good at the time.
Are there baffles in future designs to prevent slosh?
There were baffles, but one may have acted like a straw to suck bubbles in from above liquid/gas level. Something similar happened on an early Falcon 1 flight, resulting in unexpectedly high liquid oxygen residuals at main engine cutoff.
I'm curious what this green flash is, if it were Falcon 9 the no brainer answer would be TEA-TEB - but Raptor just uses spark ignitors. It was visible during engine ignition for SN10's flip maneuver, specifically when the third and final engine lit. @elonmusk @NASASpaceflight
Green flame in this context means engine is burning internal components made of copper. This is usually followed by a RUD (Rapid Unscheduled Disassembly).
In this image you can see the imprints left by Starship SN10 landing legs before RUD.
Happy 3rd anniversary to SN10, the first ship to land hardly...or hardly land? Two days later, we took this photo of its remains: