BigP

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As always, Scott Manley absolutely slays with an analysis I can't find much fault with (okay, any). I didn't have time to rerun the footage dozens of times in slow-mo to catalogue every detail but I did have eleven minutes for this.

I stand by my initial determination of over rotation for the booster at separation and Scott takes that further and demonstrates the consequent propellant slosh and starvation issues. I wondered if there was something hinky with the Ship at about 7 minutes and Scott shows that the LOX starts draining abnormally fast at that point. Just magnificent analysis.


View: https://www.youtube.com/watch?v=hF2C7xE9Mj4
 

Shavano

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As always, Scott Manley absolutely slays with an analysis I can't find much fault with (okay, any). I didn't have time to rerun the footage dozens of times in slow-mo to catalogue every detail but I did have eleven minutes for this.

I stand by my initial determination of over rotation for the booster at separation and Scott takes that further and demonstrates the consequent propellant slosh and starvation issues. I wondered if there was something hinky with the Ship at about 7 minutes and Scott shows that the LOX starts draining abnormally fast at that point. Just magnificent analysis.


View: https://www.youtube.com/watch?v=hF2C7xE9Mj4

the video shows that Starship only reached a little over 24000 kph which is about 3000 kph short of orbital velocity, and at that point it had very little fuel left; probably not enough to have reached orbital velocity. So I suspect they were not getting the planned thrust out of the engines for some reason, even before the failure of Starship became obvious. That's independent of the booster failure. There were definitely multiple things that went wrong with this launch. At least 3, I figure.

Also, it will be interesting to see if they've fixed all the issues with the launch pad. There was no obvious initial damage like there was with the first Starship launch but this is still the heaviest rocket ever launched, and we won't know if the launch pad is sufficient to hold up to multiple launches until it has been thoroughly inspected for damage.
 

Shavano

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another thing to note is the failure of the booster, while catastrophic, wasn't an issue for putting things in orbit. If the booster worked correctly up to separation, which it appears to have done, that would be fine, mostly. A conventional booster (not designed to return to earth) doesn't have to do that maneuver with huge engines. These SpaceX boosters have unique challenges that were solved with Falcon 9 but apparently it's a lot harder with a really big booster.
 
another thing to note is the failure of the booster, while catastrophic, wasn't an issue for putting things in orbit. If the booster worked correctly up to separation, which it appears to have done, that would be fine, mostly. A conventional booster (not designed to return to earth) doesn't have to do that maneuver with huge engines. These SpaceX boosters have unique challenges that were solved with Falcon 9 but apparently it's a lot harder with a really big booster.
How do they do it with the Falcon 9? I've heard baffles in the tanks being mentioned. I'm sure they have some plans for how to mitigate this, probably not implemented yet because they would add extra weight.
 
It might need more than just baffles. They're working with a really large amount of LOX and LH to be able to land those stages, and they need to flip a really big thing, while not under major thrust.
Yeah, I imagine there are many different types of solutions. It seems like this type of issue could be modeled, so I expect they have some possible solutions that they haven't implemented yet (in the same way they have probably been thinking about hot staging for a while, but just decided to implement it now).

I was just guessing that it was a weight issue, but maybe it just wasn't a high priority at this stage of development.
 
another thing to note is the failure of the booster, while catastrophic, wasn't an issue for putting things in orbit. If the booster worked correctly up to separation, which it appears to have done, that would be fine, mostly. A conventional booster (not designed to return to earth) doesn't have to do that maneuver with huge engines. These SpaceX boosters have unique challenges that were solved with Falcon 9 but apparently it's a lot harder with a really big booster.
I think memories fade with well over 200 perfect F9 booster landings in a row, but it definitely took awhile and a lot of booster explosions to land the first F9 booster.
 

.劉煒

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It might need more than just baffles. They're working with a really large amount of LOX and LH to be able to land those stages, and they need to flip a really big thing, while not under major thrust.
LM, but yeah. Though i think baffles/manifold/etc might do it, since MECO is 'most engines cut off' so it's still getting constant acceleration, along with maybe a slower flip mechanism.

I miss all the fun tank-cam shots that SpX had on their YT but I'd imagine they'd have the inside of the tank with cameras and instrumented so it'd be a more straightforward fix.

No idea about the 'Ship disintegration, maybe they hit an accel limit? Rumor (somewhere) was that it was tumbling.
 

BigP

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Looking at the replays, I think that they might be able to solve the separation/boost-back issue by increasing the thrust of the 3 remaining booster engines (or adding one or two more) during the separation event to ensure a small but positive acceleration on the booster and then maintaining the booster's attitude immediately after separation for just a few more seconds to allow the Ship to pull away before committing to the flip maneuver.

Assuming we can trust the displayed telemetry (which is all I have to go with) I noticed that the booster did in fact have a negative acceleration at the separation event which I think leads to a very high risk of propellant sloshing and gasses mixing even when still moving in a straight line. And complicating that, the Ship's exhaust will provide a pretty huge kick to the far end of the booster if they are even a little out of alignment while still close. I'm now honestly hoping they've kept the design for the hot gas thrusters in their back pocket because they might be very handy to have up by the grid fins for this event.

I can't tell if the center engines were just too low to keep the full stack accelerating prior to separation or if the pushing from the Ship's exhaust overwhelmed the booster's thrust. Either way, SpaceX will probably be using yesterday's data to model the hell out of that event. The timing will be tricky but I expect they'll be able to tweak the throttle profile of the booster engines to maintain full control through the abrupt mass change of separation. Hopefully they'll nail it on the next launch but I wouldn't be surprised if it takes one or two more. :biggreen:
 

xoa

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It might need more than just baffles. They're working with a really large amount of LOX and LH to be able to land those stages, and they need to flip a really big thing, while not under major thrust.
Yeah, I imagine there are many different types of solutions. It seems like this type of issue could be modeled, so I expect they have some possible solutions that they haven't implemented yet (in the same way they have probably been thinking about hot staging for a while, but just decided to implement it now).

I was just guessing that it was a weight issue, but maybe it just wasn't a high priority at this stage of development.
A passing thought: yes of course Booster is massively larger and so on, but could this be one area where methalox actually adds a bit of challenge vs kerolox, or at least real differences they wanted flight data on? Does liquid methane being lighter slosh more then denser RP1 or behave differently enough they could have misguessed at baffle numbers or design? I'm seeing something like 420 g/L for LCH4 vs 850 g/L for RP1. I can't remember how much super chilling was supposed to increase methane density, but even with a sizable boost that'd still be a pretty radical difference. Can't imagine they didn't crunch some numbers there, but maybe it wasn't entirely clear where their line was and easier as you said at this stage to just test it and find out.

Perhaps it's also another case of "might as well try to do it in the lightest most aggressive way first, we've got lots of mass margin we can slowly add on after, if it works great free mass if not we'll throw a bit more at the problem and refine it over the years later"?
 
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For booster, i'm going to propose something slightly different from Scott Manley. I initially thought that there was a lot of cold gas thrusting going on during the flip over: I now suspect that one of the engines exploded on re-light. There's a lot of gas trailing that I wouldn't have expected.

If that was a raptor re-light explosion, I bet it did all sorts of bad things like e.g. collapse the internal common bulkhead in the fuel tanks.

(I don't work for SpaceX, but I suspect they've used every trick in the book and then some to get this thing light enough).
 

BitPoet

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(I don't work for SpaceX, but I suspect they've used every trick in the book and then some to get this thing light enough).
If they follow the same development arc for Starship that they did for Falcon9, I'm betting this is still pretty conservative in order to increase the error margins/chance of success.
 
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gregatron5

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Has anyone else lost their enthusiasm for SpaceX? I want to be excited for what's going on, but I just can't anymore, much though I love rockets. I mean, I watched, but I was hardly as enthusiastic as I was during the early Falcon 9 days, or even the early BFS days. It was especially hard to see Musk holding the child he's illegally avoiding service for and keeping from his mother.

I wish the boards of SpaceX and Tesla had the guts the board of OpenAI had.
 
I wish the boards of SpaceX and Tesla had the guts the board of OpenAI had.
"Bull in the China Shop" level of spastic is what you're looking for in a company? Have a seekret Board meeting with 4 of 6 Board members and fire the guy you then try to rehire less than 48h later when it all blows up?

Not me.
 

.劉煒

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Still super enthusiastic, tbh. Lots of awesome things going on - wish it was easier to livestream on the TV but hey ... being up at 5am to watch a launch is kinda hard on the body, so the phone might work better there.

And SpX's successes are definitely due in part to Elon's leadership and ability to pivot on engineering decisions.
 

Ecmaster76

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And SpX's successes are definitely due in part to Elon's leadership and ability to pivot on engineering decisions.
Musk is undeniably an asshole (and that is probably going to keep getting worse) but his title of chief engineer is deserved.

He doesn't need to know the most about every single discipline required for SpaceX but he definitely knows enough about each of them to shape the vision and make tough calls. Sometimes he gets those calls wrong but usually not.
 

demultiplexer

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Has anyone else lost their enthusiasm for SpaceX? I want to be excited for what's going on, but I just can't anymore, much though I love rockets. I mean, I watched, but I was hardly as enthusiastic as I was during the early Falcon 9 days, or even the early BFS days. It was especially hard to see Musk holding the child he's illegally avoiding service for and keeping from his mother.

I wish the boards of SpaceX and Tesla had the guts the board of OpenAI had.
I'm not even that worried about Musk's involvement purely because he just doesn't seem to have anything substantive to do with the company anyway, and hasn't for a loooooong time. Like, SpaceX from an engineering perspective has been doing the right things - and has explicitly not been doing a lot of things Musk said - for a decade or so.

But the working culture and general techbro attitude towards everything is very grating. SpaceX has recently become kind of the anti-aerospace company. Normal rocket companies are actually really environmentally conscious (typically being staffed by a lot of EO people), but SpaceX just fucks up major and rare nature reserves without any mention of it caring. They source their materials from the open market, with a few elements being notoriously from dodgy sources. They have a terrible high-pressure work culture, which from a working hours perspective isn't unheard of (academia isn't great either) but this is a few steps beyond working at NASA or Boeing or ULA.

If your goal is to change the world, but in the process you ruin the world you live on, I don't know if you're really that altruistically trying to do good. Leading by example is the way to go.

Musk is undeniably an asshole (and that is probably going to keep getting worse) but his title of chief engineer is deserved.

He doesn't need to know the most about every single discipline required for SpaceX but he definitely knows enough about each of them to shape the vision and make tough calls. Sometimes he gets those calls wrong but usually not.
As an actual aerospace engineer, he gets a lot wrong or is obviously ignorant of the engineering process behind choosing something. He can bullshit his way through rocket dynamics 101 but that's basically it. This is fine by the way, I don't expect a CEO or somebody so far removed from the process to have any real knowledge on the matter. Every facet of rocket engineering is something you can dedicate your entire life to and still find new stuff, and in a lot of cases the design space is just really large and there is no obvious best way to do something - you just have to work through the details or try stuff.

The thing SpaceX needs to be lauded for, and really the innovation of all innovations here, is that they're actually doing stuff. NASA, JAXA, ESA, they've all had really good rockets that even rival SpaceX's cost and surpass their safety record - but they don't exist anymore. NASA's and ULA's attempts at a new launch platform has been stymied, for political, funding and actual engineering failure reasons. Meanwhile, SpaceX has been steadily progressing. Still very slow, especially compared to the 50s and 60s, but at least stuff is getting done.
 
Musk is undeniably an asshole (and that is probably going to keep getting worse) but his title of chief engineer is deserved.

He doesn't need to know the most about every single discipline required for SpaceX but he definitely knows enough about each of them to shape the vision and make tough calls. Sometimes he gets those calls wrong but usually not.
His aversion to the sunk cost fallacy is pretty damn clutch as well.

At an OldSpace company, they'd probably still be screwing around with carbon fiber and barely past Starhopper rather than scrap millions in tooling they just bought.
 
but SpaceX just fucks up major and rare nature reserves without any mention of it caring.
Not this bullshit again.

Despite media clickbait articles, your premise appears to be grossly false. Please provide appropriate evidence which convincingly contradicts the long discussions we've had on the topic.
 
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Ecmaster76

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Normal rocket companies are actually really environmentally conscious (typically being staffed by a lot of EO people), but SpaceX just fucks up major and rare nature reserves without any mention of it caring. They source their materials from the open market, with a few elements being notoriously from dodgy sources.
Wait, you are seriously lading companies who still routinely fumigate their launch sites with solid rocket exhaust?

Versus what exactly that spacex has done? Sand, rocks, and stainless steel?
 

gregatron5

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"Bull in the China Shop" level of spastic is what you're looking for in a company? Have a seekret Board meeting with 4 of 6 Board members and fire the guy you then try to rehire less than 48h later when it all blows up?

Not me.
Touché. I posted before the board whiplash.

I read an article a few years ago I wish I could find… it's about having one developer (my profession) that does some amazing things, but is a total asshole and no one can stand them or work with them. It kills morale for the entire team and makes the end product worse because of one person's outsize influence and insular practices.

But more than that, morally and ethically he's a disgrace as a figurehead. Based on media headlines (I try to not read articles about Musk), he's more concerned with validating and platforming right-wing authoritarian fascists and avoiding legal service for keeping his child from its mother than he is with actually building rockets anymore. (Or building cars, for that matter.)

I don't mean to turn this into a SB thread, but it is about SpaceX, and I think SpaceX would be well served by saying something like, "We respect and appreciate all that Musk has done for us and the space industry, but his current behavior is at odds with our core mission, and we regrettably have decided to part ways with him."

[Edit] Removed potentially inflammatory Godwin's Law statement.
 

Quarthinos

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I don't mean to turn this into a SB thread, but it is about SpaceX, and I think SpaceX would be well served by saying something like, "We respect and appreciate all that Musk has done for us and the space industry, but his current behavior is at odds with our core mission, and we regrettably have decided to part ways with him."

[Edit] Removed potentially inflammatory Godwin's Law statement.
You do realize that Space Exploration Technologies is a privately held company and most of the ownership is by Musk?
 
You do realize that Space Exploration Technologies is a privately held company and most of the ownership is by Musk?
Nitpick: I'm pretty sure Musk was diluted to minority ownership (plurality? Under 50%, biggest owner) between some 2021 and 2022 filings - but he retained >75% of the voting power.
 
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Auguste_Fivaz

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In today's edition of spaceweather.com is an article titled "SPACEX AURORAS." Interesting reading on the impact of F9 launches and reentry on the ionosphere and some ongoing investigations by the fine folks at McDonald Observatory.

https://spaceweather.com/archive.php?view=1&day=21&month=11&year=2023

For Jeff Baumgarder, who has his own dedicated camera at McDonald, the events are a golden opportunity for research.​

"The saying 'one person's signal is another person's noise' is appropriate here," says Baumgardner. "We are delighted with the rocket burns. They give us an opportunity to explore how space traffic affects the ionosphere. The ionospheric density is different night to night, so we can learn something about the efficiency of the chemistry by observing many events."​
 

Quarthinos

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Nitpick: I'm pretty sure Musk was diluted to minority ownership (plurality? Under 50%, biggest owner) between some 2021 and 2022 filings - but he retained >75% of the voting power.
Don't follow the financials at all, thanks for saving me from an 'akshully' later!
 

PsionEdge

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The thing SpaceX needs to be lauded for, and really the innovation of all innovations here, is that they're actually doing stuff. NASA, JAXA, ESA, they've all had really good rockets that even rival SpaceX's cost and surpass their safety record - but they don't exist anymore. NASA's and ULA's attempts at a new launch platform has been stymied, for political, funding and actual engineering failure reasons. Meanwhile, SpaceX has been steadily progressing. Still very slow, especially compared to the 50s and 60s, but at least stuff is getting done.
I think I saw a tweet that basically covered something to this. After the launch on Saturday numerous headlines were "rocket explodes/fails" since they lost contact with the starship stage.

SpaceX can handle these headlines because they are privately held and don't care about the media spotlight in this regard (Musk notoriously cares about the media spotlight in many other aspects). NASA can't have failures because if that happens, then the funding for a program is removed so congress critters can say "Look here voters, I'm not spending your money on boondoggles! I cut this failed NASA rocket/satellite". The other nice part of being privately held is you don't have stockholders to complain about your R&D projects. Has anybody projected Starship/Mars to be a profitable line of business in say the next 50 years?
 

Ecmaster76

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MilleniX

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Has anybody projected Starship/Mars to be a profitable line of business in say the next 50 years?
How far from profitable do we think Starship is expected to be just at the level of launches supporting Starlink and the NASA lunar HLS contracts?

Then start shifting over the rest of the Falcon 9 business
 

MilleniX

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I don't think that there are enough people who care in the least about spaceflight anyway. Unless there's a sexy picture of a blowup, I'll bet most won't even open the article to read it.
Even if they do care, they have zero power to do anything with their concerns. Again, because SpaceX is privately held, and operating (at least mostly) within the law.
 

.劉煒

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I don't think that there are enough people who care in the least about spaceflight anyway.
I swung by an aerospace museum today to take a look at the new F117 exhibit and yeah, half the people coming in didn't even know about saturday's launch. Was standing there chatting with a docent who used to work for aerojet et al as a propulsion engineer. Good conversation.
 

spiralscratch

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I read an article a few years ago I wish I could find… it's about having one developer (my profession) that does some amazing things, but is a total asshole and no one can stand them or work with them. It kills morale for the entire team and makes the end product worse because of one person's outsize influence and insular practices.

Maybe one of the articles on so-called rockstar/10x devs that were somewhat common a few years ago? This one sums up a couple such instances.
 

Shavano

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"Bull in the China Shop" level of spastic is what you're looking for in a company? Have a seekret Board meeting with 4 of 6 Board members and fire the guy you then try to rehire less than 48h later when it all blows up?

Not me.
OpenAI's problems are unique to having a NFP have a for profit subsidiary with goals diametrically opposed to the parent.
 

Jonathon

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