Comment by staplung
4 days ago
Summary: almost, but not quite entirely successful.
Launch successful. Booster separation and boost back burn looked good. Booster failed to relight some of its engines and hit the water hard. Successfully deployed the 20 starlink satellites. Successfully reignited an engine in flight to prove potential for de-orbit burn on future flight. Re-entry looked good and less spicy that some previous attempts (subjective). Such a soft landing that the ship flopped into the water without exploding and floated for a good long while (possibly still floating for all I know). Got some great drone footage flying over the heat-shield.
So the ship itself is looking increasingly good (so far) but they still seem to be having some issues with the booster.
Speaking of which, are there any fan theories on why the boosters seem to have persistent issues? Or is the plumbing still churning fast enough that we keep seeing N=1 issues for successive designs?
The 12th flight was the first to use the third generation Raptors, so this is only their second flight test.
Until the past couple launches it was the ship that had the issues. Had to be blown up a couple times, failed to relight in vacuum, lost an engine and nearly failed to get to the suborbital trajectory last time. Meanwhile the booster had the most spectacular success in the catch, and has yet to result in a catastrophic failure.
The leading theory, from what I can tell, is slosh. The flip on separation is relatively violent, and while there's not much fuel left compared to the amount at launch, it's still heavy enough to do damage.
The cast I was watching said that during the flip and boost-back the booster is pulling 11 Gs. That's a pretty hard hitting water-hammer for sure.
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