SpaceX SN9 Successful Flight But Crashes Again

SpaceX SN9 Starship matched the SpaceX SN9 Starship flight and also matches the crash on the final attempt at landing.

There still seems to be difficulty getting the header tank issues resolved. They needed two of the Raptor engines to restart when they were about 400 meters in altitude but only one fully lit.

SpaceX Starship SN10 is ready for its launch. RIP SN9.

Written by Brian Wang,

38 thoughts on “SpaceX SN9 Successful Flight But Crashes Again”

  1. I love that these failures are so spectacularly public, that it quite literally is blowing up in their face. Because, when they figure this out, and they will, it's going to be like the internet boom for space and the IOT will give rise to the SOT (space of things).

  2. Yes Elon has agreed starting three engines is the way to go but they will need to do more than that. I consider Raptor reliability their biggest challenge.

  3. Have they determined why one of the engines failed to relight yet?
    That is the issue, how to consistently relight Raptors while experiencing changing gravitational forces.

  4. I think they should melt the metal down to make Engineering Rings, instead of using the metal from that old bridge. This can be the new 21st-century update to that old tradition, to give new inspiration and impetus to future engineers.

  5. Well, like I said, rolling mills are mucho expensive. The estimated minimum capacity to be economical is about 1 million tons output per year, optimally 6 million tons per year. That's about the mass of 20,000 complete Starship/Superheavy stacks. I really don't see them reaching production levels that would even begin to justify owning such a facility.

    If you're ordering large amounts of steel, the existing mills will run custom heats for you, so having a special alloy doesn't imply needing their own production facility, unless they were trying to keep it proprietary.

    OTOH, at some point they might want to move that in house, and sell the excess capacity. Nothing says "priority customer" like a controlling interest, and the quality control for rocketry applications is quite a bit more strenuous than even automotive.

  6. As a general rule, if your idea requires adding a significant amount of steel, it's impractical for a rocket. Rockets are really, really weight constrained.

  7. Done. Remade the comment on the appropriate post and edited and removed the comment to reflect it, just stating the reasons for editing.

    I wonder how many other people on the internet admit when they are wrong. The numbers would probably fit in the Vatican City.

  8. The last post by Brian was about politics, about how the FAA would not grant SpaceX lifting permit, and so the comments continued on this line of reasoning. This post, however, was purely about technology and so was the commenting.

    Until your comment, that is….

  9. If they have to rely on only the fuel/oxygen in the header tanks, there might not be enough there for a longer powered descent. It might be that to experiment the way you suggest, they'd have to build some prototypes with smaller main tanks and larger header tanks.

  10. I have seen in some article, somewhere, that eventually they intend to use a stainless steel alloy they develop themselves. I have no idea whether that, combined with the often-stated intent to produce thousands of Starships, would make it reasonable to build their own mill. Still, I think you are correct that they currently do not have their own mill.

  11. Ah, new idea, an Archimedes screw that is welded in place within the tank against the sides of the tank. When the ship goes on its side the fuel should stay in the bottom. When it rights, the fuel will by gravity just go to the bottom. And there should be ample fuel movement so the engine is not starved due to consumption when there are a lot of engines sucking up fuel rapidly.

  12. A hollow open-ended cylinder like an open can upside-down should retain the volume for fuel in the tank but also avoid twisting and letting the fuel past it. It just goes down as fuel is used. Another possibility that avoids gasses rather than fuel getting in the engine would be deforming the tank like a tube of toothpaste/an accordion. Reusability, though, is essential. Reinflating a dinted up tank and that tank remaining viable for multiple launches seems insurmountable.
    I may be ignoring that the fuel itself may be becoming the vapor.
    Maybe they can use the engine vibration and some texture or shape inside the tank to bias the liquid fuel movement to the nozzle end. But there are a number of crazy solutions possible. 
    Maybe it could be a bit like a nautilus shell with several funnel-shaped levels in the tank with a one-way valve in the center of each. Whatever sloshing happens, the fuel should move toward the nozzle rather than away.
    Yeah, I think I like the last solution. It adds a few movable parts in the tank (valve gates) but they should be reasonably durable, and don't require any resetting.
    Hmm, looking at their design, they have header tanks. They could put the system in those, or forget the hedder tanks and use the system in the larger tanks.
    They need to do some scale testing, and waste less big rockets. It looks like they need some redesign. Crashing more rockets is unlikely going to solve this, even if you get a few lucky landings…this could recur.

  13. Yeah, the partisanship is getting ridiculous, counterproductive and downright old isn't it? Not to mention costing us international respect. These media algorithms and partisan "news" outlets with an aversion to the truth and affinity for division and slant are causing a lot of damage.
    I take it this was tongue in cheek humor, right?

  14. I agree with everyone. They should lit all three raptors, throttle them down. And they should do the landing maneuver higher to give the system a little more time. Try for a successful landing. Can get more aggressive later.

  15. Such sloshing would be worse in space??? If aero forces are there, and in correct direction, they should *help*?

  16. Edited, as it was a political comment in answer to political comments on the previous NBF post regarding the FAA grounding of SN9.

    Jan Janson was right. It doesn´t belong here. Thus, I reposted the comment on the FAA Grounding SN9 post.

  17. I was thinking the same thing seems to me as a laymen that the flip is just happening at a over aggressive low altitude assume to save fuel but for test purposes it would seem to be better to do the flip at a higher altitude would give them more time to stabilize before descending down for the landing. Further test could then continue to drop the flip altitude until they got down to the desired sweet spot.

    It just looks to low to give the systems time to get everything stabilized in time to make a easy landing. She still was doing allot of wobble when she hit this time. First time was more stable just not enough power to bleed enough speed.

  18. I would pay for a piece! I’m sure a lot of folks would pay a lot more than me as well.. seems a somewhat easy add on for publicity.

  19. So they're not getting the fuel pressure they expect. Tank's not sloshing the way they expected?

    It won't surprise me if they hit an unexpected bump on the road.

    That kind of maneuver was only attempted on DC-X before AFAIK, and it was at a much smaller scale, with a different fuel and engines.

  20. Well, a success at reaching orbit and a crater coming back.

    I assume they don't need an actual belly flop to test the successful restart fuel pressure envelope; That they can do on a test stand.

    So they're not getting the fuel pressure they expect. Tank's not sloshing the way they expected? How I'd love to be a fly on the wall at their post flight discussions.

  21. I wonder what they do with the scrap metal?

    My son and I think they should melt it down and cast it into commemorative figurines, as a fund raiser. Frankly, the scrap value of 304 is hardly going to pay for the clean up otherwise.

  22. Perhaps they should launch a test flight where they end the belly flop high enough up to make multiple restart attempts before hitting the ground? Alternatively, they have three engines, try to restart them all, and shut the third down if one doesn't fail.

    I mean, this is dramatic, but the raptors are expensive, and they're losing three with every crash.

  23. If anything, they know how to make a good show..

    Good thing is, there is SN10 already waiting, ready to be launched in a couple weeks, or as long as fixing the problem with SN9 takes.

    Also, let's notice they started with the hardest part. Throttling down a rocket and igniting it mid flight is really hard. Falcon 9 failed the landing several times over before pinning it down.

    Had they started in the traditional way, launching the full stack to orbit, they would probably already have a success on their belt.

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