It seems that several engines weren't just shutting down during the boostback burn, but were violently disassembling themselves. Possible cause could include propellant sloshing during the flip leading to inconsistent pressure fed to the engines/plumbing.
He speculates that B9 engine failure during boostback was due to either fuel slosh, fluid hammer, or a combination of both. It's unclear whether the booster FTS was triggered or whether the Booster RUD happened on its own.
For S25, he notes that a puff of gas just after T+7 minutes coincides with a drop in the LOx gauge. This indicates an oxygen leak of some sort, which could have any number of causes.
Based on the last altitude/velocity numbers on SpaceX's webcast, I estimate a Starship achieved trajectory of -1740 x 150 km with (if not entirely destroyed by the flight termination system) impact NE of the Turks and Caicos Is.
Wow, my skepticism about the engines was silly. There were a few moments during first stage where it I couldn't tell whether the exhaust was nominal, but may be nothing. (Edit: Nvm, I think it was just ice chunks)
Looks like there's some minor debris on the road near LabPadre's camera, but certainly no concrete storm!
Totally! I don't have an engineering reason to think they'll fail, I'm just suspicious after the static fires couldn't maintain 33. A hot staging failure would be MUCH more exciting.
This is a really hot take, but I reckon if it manages to make if to stage separation in one piece, and the hot staging works, the ship should fly trouble-free.
It's the one part of the system that they have done significant testing on, not that many engines etc.
If they once again don't make it past staging that would be very concerning for the Starship timeline, Artemis, and so on...
It'll be so cool to see the booster soft splash.
Biggest hope is that they manage to get away without sandblasting Boca Chica so the FAA don't ground them for 6 months again.
Hmm, I am a bit more confident in the ships abilities (at least for anything between hot staging and SECO).
Anyways, if it gets to the point to initiate hot staging (regardless of the outcome) and the FTS works, it‘s a success. But we should also remember that SN9 landed (crashed) harder than SN8, and SN12 was way worse than the previous three tests. If stage zero is mostly unharmed, the FTS works, and the authorities are not too unhappy, SpaceX has already produced enough hardware for several tests to get it right within the next few months. A good test is a test where you learn a lot, and can try again soon.
Yeah, that was a bit unusual. Last time we got a bunch of different views (booster cam, ship cam, flap cam, etc), but none this time. There was also a communications blackout period just before scheduled SECO where it was unclear whether the FTS had triggered or not.
Were there fewer ground stations along the flight path than for IFT-1?
If the SpaceX overlay graphic is accurate, it seems like a number of engines went out shortly after the relight for the boostback burn, around T+02:53. Asymmetric thrust could have contributed to extra rotation and loss of control.
For people like me without an X/Twitter account, there is also the spacex.com livestream (which is just the Twitter livestream embedded, but no login is required).
My tv doesn't have a Twitter app and I'm too lazy and tired to get off the couch to turn on my computer, so I guess I'll stick with unofficial Youtube streams for now.
John Insprucker: Teams are not working any significant issues. Propellant load progressing well. Stages are pressurizing for flight. Booster prop load should finish around T-3 minutes. Still a few wayward boats in the area, but the countdown can be held at T-40 seconds if necessary.