Thursday, April 20, 2023

The Big Story is the Big Rocket

I'm sure everyone has heard by now that SpaceX launched the booster7/ship24 combination today, for the first test flight of the combination of a Starship and Super Heavy booster.  The combination didn't get quite as far as the so-called "successful failure" of the Relativity Space Terran 1 flight last month.  Terran 1 had a successful first stage and a second stage that didn't ignite properly.  The B7/S24 ship never got to the point of stage separation and trying to light the second stage.  Instead, the Flight Termination System detonated and blew the vehicle apart, after it should have dropped the first stage and gone on to the upper stage.  

Still, I'm inclined to call this one a successful failure, too.  The "Space 2.0" companies, notably led by SpaceX, are characterized by being "hardware rich" - that is, build lots of hardware, test important changes frequently, understand the failure, learn from it, and build more hardware.  The truth is, B7/S24 was fairly far behind the next candidate for flying, which I've heard is to be Booster 9 and Ship 26.  

Comments, photos, and speculations are flying at an enormous rate.  I have a tendency to think, like pretty much every breaking news story we see on the media, some of the first reports are going to be wrong.  Still, there are things we can see ourselves.  In the comments to yesterday's post, an anonymous commenter posted a link to a decent video from the Wall Street Journal.  During ascent, around Max Q, the camera is looking right up the skirt of B7.  It's clear there are six engines that are no longer firing.  I've added red rings about where those engines are. 

You can watch the video here, I need to add, though, that different videos and different photos show different numbers of engines out at different times in the mission.  The video has representation of the engine view showing which engines are out at the lower left of the screen.  If you watch carefully, you'll see that the representation has some engines turn off and then back on.  I don't know if that's really happening.  

Fellow blogger BillB posts a picture from NASA Spaceflight showing eight engines out. 

In the long topic on NASA Spaceflight.com, I took a photo posted by SpaceX and did some processing on it to get a better look at the engines. 

To me, the pattern of engines that aren't working in this picture is the same as the WSJ video showed, above.

A major question is how much damage has "Stage Zero", the ground infrastructure, suffered.  Lab Padre tweeted this picture of the Orbital Launch Mount, showing the concrete and sand under the mount was blasted out.  Lab calls this "Crater McCraterface".   I did some photo editing to increase the contrast. 

There are also Tweets that show damage to the large storage tanks SpaceX has close to the OLM.  Major construction here could seriously impact the ability to resume testing with another booster/ship combination quickly.  Major construction to improve their water deluge system has been underway, and if they're lucky, a lot of that concrete would have had to have been removed anyway.  

At this point, it looks like the engines failing are a fundamental problem.  Raptor engine problems aren't new, and part of the reason for the Raptor 2 engines is to help alleviate that.  I don't know what engines were on B7; if they were all up to the latest and greatest versions.  That doesn't mean there aren't more problems or bigger problems in the Starship and Super Heavy portions of the vehicle.

There's going to be a lot of conversation about today's flight as analysis proceeds and I expect the story to change.  Learning is part of the fun.


EDIT TO ADD, 4/21/23 @ 4:45 ET: 

This photo posted today to the NASA Spaceflight discussion.

This is the base of the Orbital Launch Mount (OLM) showing how the concrete was blasted of the rebar that it was cast over.  There's some water visible near (in front of) the leg on our left.  It also blasted the cover off that leg - sheet steel, I think. 



19 comments:

  1. Simply wonderful to watch. I expected it to blow up, but it was so successful, passing max pressure and I imagine they'll find the issues and fix them - that's what Musk does. I expect the next one to blow up, too. All part of the plan.

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  2. There's a theory circulating that the HPUs exploded at T+0:35 and T+1:05, if memory serves correctly. That would explain the eventual loss of gimbaling and the failure to separate stages.

    https://twitter.com/search?q=hpu&src=typed_query

    Agree it was MARVELOUS to watch.

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  3. So far it's as successful as the Soviet N1! 😁

    It was beautiful to watch.

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  4. One wonders if the final "boom" was the result of the second stage ignition before first stage separation?

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    1. No, that was the Flight Termination System doing its job. Whether commanded by ground or the onboard computer is irrelevant.

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    2. So instead of an RUD, it was actually a Rapid Commanded Disassembly (RCD)?

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    3. FWIW, everything I've read says it was the FTS working autonomously.

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  5. The launch was totally awesome! The damage to the site and the flying concrete chunks was incredible. SpaceX got a TON of good data including the simple fact that the whole stack was spinning like a top and it still held together!!
    Post-mortem analysis is gonna keep 'em busy for a while, They don't have to dig far for a flame trench now, do they?!

    Oodles and oodles of work to be done. The second launch ought to be cleaner and better, because this booster had the original design Raptors on it, as well as the HPUs which are obsolete now - electric thrust gimbaling will be on B9 and starship now. The HPU loss may have been the reason for no separation, we'll see what the analysis says.

    All in all, A Very Good Day for SpaceX! Excitement promised, excitement delivered! Wheeeeeeeee!!

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  6. "...... if they're lucky, a lot of that concrete would have had to have been removed anyway. ".....or did they count on that?
    Legacy media coverage was awful. Due to reasons, I had to watch the abc news live stream, which carried the SpaceX video but had some prettyboy talking head discussing the event with a former(?) NASA shuttle payload specialist. She was frustrated, answering his banal questions while trying politely to get him to let the SpaceX commentary on the live stream run.
    ugh,
    Differ

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  7. Shatner's been in micro-orbit.
    I'm just disappointed that Musk hadn't used this flight to get the coven from The View a halfway trip to space.
    Another golden opportunity blown to pieces.

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  8. Space flight is expensive and dangerous like powered aircraft of the days of Kitty Hawk. Pushing the limits induces failures so you can study and improve the next try.

    Makes you wonder just how deep Musk's pockets are given the other rich man's space toys stoppages lately.

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  9. I rather strongly suspect most of the engines were out because they were hit by flying concrete. I think the failure of Stage 0 to control the exhaust plume on launch is what doomed the entire flight to an early end. Somewhere there is a plot of the telemetry showing acceleration curves and altitude, and it clearly didn't get anywhere near stage separation. The spin happened because both HPUs exploded (seen in video) and the airframe couldn't control itself and went into an increasing magnitude spin. They fired the FTS from the control room

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    1. Is this plot of telemetry the one you're thinking of?

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    2. Yes. Good find, I couldn't locate it again.

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    3. FAA sez it was an automatic termination signal NOT from the ground. Apparently it stayed close to the flight path before it went totally out-of-bounds and the flight computer said, "Nope!".

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  10. Thank you for the coverage SiG.

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    Replies
    1. You're welcome, but it's kinda like saying, "thank you for having fun." It's pretty easy.

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  11. Looking at the slow takeoff and horizontal movement of the rocket at launch makes me wonder if several engines failed to start at the get go. That would mean longer time near the ground, leading to the extensive damage to the OLM, and asymmetric thrust would explain horizontal movement that was corrected by other engines rotating on their gimbals to compensate. That would be really impressive!

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  12. I published the picture at the end of the blog post and deleted the comment that had I had put here before:

    That view of the OLM and the massive cratered concrete pit need to see this picture with a different view of the destruction.

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