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Cake day: April 14th, 2024

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  • I use syncthing to sync almost everything across my computer, laptop (occasional usage), server (RAID1), old laptop (powered up once every month or so), and a few other devices (that only get a small subset of my data, though). On the computer, laptop, and server, I have btrfs snapshots (snapper). Overall, this works very well, I always have 4+ copies of my data in 2+ geographical locations.











  • 3 weeks, roughly in line with faster Space Shuttle turn around times

    The shortest shuttle turnaround time was 55 days. Almost three times as much as Falcon 9. The fastest post-Challenger turnaround time was 88 days, I believe. After Columbia, the fastest turnaround was around 5 months.

    NASA claimed that the shuttle could achieve a turnaround time of two weeks (page IX). It looks like SpaceX is not the only one setting unrealistic timelines?



  • I just compared the footage from various points in time. The flap positions for T+00:48:12 (pre-entry) and T+01:05:41 are almost the same, then it rotates about its rotation axis until T+01:05:44, but suddenly it starts to rotate about ANOTHER axis, and at T+01:05:47, its at a completely new angle. I think T+01:05:44 is the point where the flap finally breaks (after touchdown, but before splashdown).

    I think we have seen motion as fast as the one at T+01:04:22, but the subsequent bounce is surprisingly strong. I still think that the flap was still under some control at that point.

    I heard rumors on reddit that SpaceX deliberately removed a single tile on this flap for testing purposes, but I could not find any reliable confirmation for this. They deliberately removed tiles on the engine skirt, though.


  • I expect the flap on the opposite side of the ship experienced a similar level of destruction. Well, that depends on whether the damage occurred because of a general loss of structural integrity because of excessive heating, or if specific localized damage on that flap allowed plasma to penetrate the heat shield, resulting in the damage that we observed. So, general structural failure vs. random damage at that location cascading into a hole in the flap.

    Anyways, I am pretty sure that the complete loss of control authority on one of the flaps would be catastrophic. But the movement that we observed seemed pretty deliberate and consistent to what we saw during the suborbital test flights. Especially the unfolding of the flap at the T+01:05:42 mark is EXACTLY what we saw during the high-altitude flights, e.g., see SN8 @ T+6:33 or SN9 @ T+6:18. The forward flaps are folded back at first, and then rotate into a position perpendicular to the surface of Starship. The movement (for IFT-4) is precise, consistent with previous flights, and stops abruptly in the correct position.


  • That was some Columbia-level damage that Starship experienced during reentry, and yet it successfully retained control authority, completed a soft landing, and everything was live streamed. Amazing!

    The booster seems to be almost ready for the first catch attempt (depending on the accuracy of the landing).

    I wonder to what extent they can retrofit Ship 30 to reinforce the hinge of the flaps, and how long that is going to take? On the other hand, the ship did survive, so maybe they will just repeat the launch without any major fixes, and try a few different things? (Deorbit burn, maybe even suborbital test-mass deployment, or more aggressive tests of the heat shield?)

    The next-generation Starship design has less exposed flaps with reinforced hinges already. But is it already in production?



  • shadowtofu@discuss.tchncs.detoScience Memes@mander.xyzName & shame. :)
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    6 months ago

    This article has been removed at the request of the Editors-in-Chief and the authors because informed patient consent was not obtained by the authors in accordance with journal policy prior to publication. The authors sincerely apologize for this oversight.

    In addition, the authors have used a generative AI source in the writing process of the paper without disclosure, which, although not being the reason for the article removal, is a breach of journal policy. The journal regrets that this issue was not detected during the manuscript screening and evaluation process and apologies are offered to readers of the journal.

    The journal regrets – Sure, the journal. Nobody assuming responsibility …