45 thoughts on “SN10”

    1. Someone needs to coin a law about self-selected Internet aerospace commentators. Maybe something like “In any large group with an audience, those who insist on talking the most know the least.”

      They remind me of the kind of B or C list celebrities who provide commentary on a Thanksgiving day parades, talking about how many cubic feet of helium it takes to inflate the giant Snoopy balloon. You get far more technical expertise from sports commentators covering the America’s Cup, who talk about the nuances of foil hydrodynamics and control systems, stability and control, lift and drag vectors, torques, induced drag, etc. Instead, we’re regaled with the equivalent of “This float used 29,000 roses and celebrates Scobby Doo. I wonder how they get Scooby’s tail to wag like that?”

      1. Well said. I did notice that Lab has gone more YouTube pro since SN8. Now they have a person to answer all the “super sticker” questions. Lots of repeat questions of “which camera will show the flight”. Annoying, but still preferable to NASA spaceflight’s “let us show how knowledgeable we are by telling you things like you are a child that hates math and science.”

      2. Agree about both the commentary and the parade analogy. Anent the parades it’s also fair to point out that the floats look like junior high efforts compared to what the Brazilians turn out for Mardis Gras every year. And just to rub it in, the Brazilians also liberally festoon their floats with gorgeous brown topless women.

        Now where was I… oh yeah, SN10.

        The post-landing flames seem to indicate the internal plumbing still has a few chaseable bugs.

        The slight tilt after landing is pretty much SOP for the current minimal-expedient landing leg design. The late SN5 & SN6 were also a bit out-of-plumb when the dust cleared after their landings. And they had the same excuse – landing on a single, off-center engine.

        One of the Raptors appeared to have a bit of a propellant mixture control problem on ascent and descent. Its plume was more brownish than the others and I noticed periodic evidence of smoke in the plume on the way up indicating at least a small bit of dynamic propellant feed variation with that engine.

        All in all, another solid step forward in the Starship test campaign. There’s still some engine work to do and the whole launch process is also far from the usual glitch-free routine we’ve come to expect from F9/H missions. But that will come with additional refinement work, time and practice.

        Looking forward to SN11. I hope it flies well before the end of March.

        1. During ascent one of the engines was definitely running fuel rich, with yellow exhaust at times.

          1. Yes. And the fuel richness seemed to vary a bit. The upskirt tracking cam showed the plume with alternating episodes of smoke and no smoke.

            Could be this engine was also the source of the post-landing methane leakage that destroyed the ship a few minutes after touching down.

            Still, in terms of accomplishment, I’d rate SN8 & SN9 at 90% and SN10 at 95%. Solid progress was made with this test but there is obviously still a ways to go in several respects.

            The baton passes to SN11.

        2. I noticed the inflight plume coloration as well. I wonder if one of the engines did another RUD, but as it was deselected for the landing burn and the vehicle still stuck the landing.

          Is there an SN11? I thought they scrapped the rest of this series and decided to move to a newer design concept starting at SN15.

          1. SN11 is almost ready to roll out. It should fly in a few weeks. SN12 was scrapped, and SN13 and 14 were abandoned.

            I agree on the potential shutdown failure of one of the engines. I think they have some bugs to work out in both startup and shutdown.

          2. One of the engines was obviously not running a proper mixture on ascent, but it didn’t RUD because all three engines subsequently re-lit when it was time for the flip maneuver – which looked quite nominal.

            There is one more prototype in the current series yet to fly, SN11. The parts of SN12, 13 and 14 which had been fabricated were subsequently scrapped. After SN11, SN15 will be the next to fly.

            How quickly the apparently complete SN11 is brought out of its current place in the High Bay and put on a launch mount will probably be a good gauge of how straightforward solutions to today’s displayed shortcomings turn out to be. If it remains a “hangar queen” for awhile, that would indicate some non-trivial modifications being done before testing and flight.

  4. Well, that was a disappointment, but they do have time left in the flight window today, if they can figure out why the computer killed the engines.

  5. …Seems the team is evaluating whether or not they can try again today.

    Clamp release was 0.1 seconds when the abort occurred

  6. George, you are so right. Hard to stand these nitwits and their inane chatter. But I have the sound on so that I hear what Space-x finally decides for today.

    1. One of the superchat users asked about that–apparently one of the cameras they don’t talk on but I don’t remember which one.

  8. And she’s down, apparently intact. Slight bounce on the touchdown, but no obvious problems.

  14. That was better than usual. But I still can’t understand what’s with the secondary fires on the rocket including after touchdown. Plus it seems the landing legs didn’t work properly or the landing was too rough.

    Still this is quite impressive. It’s a shame they can’t reuse the engines. It must be getting expensive losing all these engines.

    1. *snort*

      Exactly! But the fourth one stayed up.

      As it was approaching touchdown, there were very large flames already licking up the side. I suspect a CH4 valve didn’t fully seat or perhaps didn’t close at all when they shut down two of the engines prior to touchdown. Or something else related to shutdown caused a major CH4 leak. That may have dropped the CH4 feed line pressure, leading a slight fall-off from commanded thrust, leading to the bounce.

    1. now it’s “I sit down okay, then I go BOOOOM”.

      I can sympathize, happens to me whenever I eat a big meal consisting largely of broccoli and beans.

  18. I wonder if SpaceX didn’t see this finale coming, they were sure quick to terminate their live broadcast after the landing. Personally, I’d like to see more coverage before & after the flights. John Insprucker is a good presenter, it would have been priceless to see his reaction to the explosion.

    1. To be fair, the live broadcast of the test didn’t start until almost T – 2 minutes, rather than 15 or 30 minutes as they do for launches; isn’t live-streaming testing a fairly recent phenomenon for just about any manufacturer?

      I noticed Insprucker had a few hot-mic moments during the ascent; “Yup, I’m clear.” “I plan to come back on about 3 seconds prior to engine shutdown.” Sounded like he was in a mask, too.

  19. John Insprucker is a good presenter, though I think he had an open mike for a bit there.

    Sorry to see the thing explode later.

    Can someone point me to a document that describes what the next
    version of test vehicle will be like?

    Thanks

  20. Scott Manley posted a good video on it.

    One thing I hadn’t noticed was the when the explosion first started accelerating the rocket, the bottom of the nose section buckled.

  21. I think Manley is right, it wasn’t an explosion, it was a structural failure subsequent to a hard landing that allowed the methane and oxygen to escape and mix.

    It points to the real problem with landing using a cryofuel. They can’t land with empty tanks and they can’t keep the methane liquid without a lot of insulation to control boil off. It has to go somewhere. I’ll bet they were showing pressure spikes when they returned to vertical from both the O2 and CH4 coming into contact with the tank walls that were on top during the belly flop and warmed up.

    I’d have some very pointed questions I’d want answered before I’d want to land in one. This is at least the second conflagration caused by not being able to control the CH4 vapor.

    1. What if you had a T-valve between the CH4 pump and the combustion chamber, so that instead of pumping the CH4 into the engine, you could pumped it into a different pipe that vented out near the top of the rocket, far away from ignition sources, or even to something like a flare stack? Or perhaps run the remaining LOX and CH4 through the RCS thrusters.

      Anyway, yesterday I was looking for information on the engine fuel valves and the interim landing legs because two things failed during the final descent. There was a pretty large CH4 fire going after the extra engines shutdown, but also quite a few landing legs failed to lock in place, and were just swinging freely.

      I was curious if there was a commonality in the control of both the CH4 valves and the landing legs, such as a high-pressure pneumatic system.

      1. Flare off the CH4. Now THAT would look cool! Er I mean it’s a hot idea!! I thought the coolest looking thing on the Mercury/Atlas launches were the verniers!!

  22. When I saw the legs, I wondered why deploy them at all? Why not just attach them in position and be done with it? It’s not like they are in the way. Possibly something to do with aerodynamics during the belly flop.

    High pressure He seems to be the most likely power source. I can’t think of any way that I’d design them that would leave them to flap in the breeze like we saw. A touch down rate of 22 FPM seems high. That’s about a 7.5 ft fall.

    Answers may be forthcoming in few days.

    1. The current landing leg system was designed before they committed to using high pressure helium for the header tanks. They were already using it to spin up the turbopumps, though.

      Could it be that the amount of high pressure helium fell short? You’ve got the initial start of three engines, the final start of three (instead of two) engines, deploying the landing legs, and maintaining the header tank pressure, possibly on a supply that was originally sized only for five engine starts and leg deploy. That might also correlate with the hard touch-down, because they’d have been short of helium for maintaining the header tank pressure.

      Anyway, I liked the graphic of just having Starship belly flop into a giant ball pit, like a little kid. All things considered, the only risk would be completely missing the landing area on re-entry. As configured, the current method would allow them to land on any concrete surface, such as a commercial runway or a McDonald’s parking lot or something.

      1. I want to work at the company SpaceX subcontracts out the lunar ball pit with erecting crane!

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