How SpaceX streamlined the Raptor engine
construction-physics.com205 points by JumpCrisscross 2 days ago
205 points by JumpCrisscross 2 days ago
According to Isaacson's biography of Musk, Musk relentlessly challenges the existence of every part in Tesla and SpaceX machines. He's willing to go too far, having to sometimes put a part back in.
Everything in the manufacturing process is also challenged to justify its existence.
This is how he managed to reduce the costs by 90%.
> According to Isaacson's biography
Isaacson’s “biographies” are glorified puff pieces. Musk is as unrecognizable in his as Jobs was in his.
Both Tesla and SpaceX had teams keeping Musk busy on bs just so that the engineering teams could do their work.
The second he took control, we got the cybertruck and the starship, the worse products both companies ever built (or attempted, in the case of the starship).
> Musk relentlessly challenges the existence of every part
This sounds insightful until you find yourself debating with the CEO for the eleventh time about how his high-school understanding of the physics involved breaks down in a particular case.
Musk is very lucky to be moving such quantities of money that his companies are big enough to protect themselves from him, if you ever wonder how Musk would fare on a tight budget, look no further than the Oceangate.
Do you remember when he bought Twitter and fired everyone, and the mass media and employee outcry was that a) the service would stop working and b) he would bankrupt the company, yet a few years later it’s massively more successful than Twitter ever was as a public business?
Regardless your thoughts on Elon, his drug habits, and his political brashness, I don’t think you can say he’s in any way close to the Oceangate guy. There is something legitimately special about him and his collective.
Twitter is definitely not more successful now than before. So many people left and are gone forever.
I would read a deep dive though into the history of Twitter (with the financials) to understand better and I do get that for a single product company there really is a point at which you give up on finding the next big thing and just optimize on your main thing and you really just need a few dozen awesome people and a rotation of new hires to keep things rolling but not thousands of engineers.
Maybe I’m overstating “massively more successful” but to my understanding “X” has roughly twice the active use count that Twitter did, although that includes Grok.
That said, do you remember these kinds of articles?
> Musk summons engineers to Twitter HQ as millions await platform’s collapse
Source: https://www.washingtonpost.com/technology/2022/11/18/twitter...
> “Former Twitter employees fear the platform might only last weeks.” Melissa Ingle: “I don’t see how it lasts the month.” “All signs point to some catastrophic failure of the system, and very soon.”
Source: https://www.technologyreview.com/2022/11/18/1063467/former-t...
> Twitter ‘to lose 32m users in two years after Elon Musk takeover’
Source: https://www.theguardian.com/technology/2022/dec/13/twitter-l...
Elon was firing people left and right and literally physically destroying Twitter’s data centers. I remember hundreds of these hysterical articles and tweets that very clearly did not come to pass. He obviously did something more clever than the authors of these articles expected… is all I’m claiming.
I haven't posted anything on this HN submission yet, but all I'm claiming is that Twitter was so successful under Elon's management that he thought it was better to roll it into SpaceX than to keep it independent. Kind of like solar city was merged into Tesla to bail it out and then it winded down after the acquisition while nobody is looking.
Just claiming, you know.
> yet a few years later it’s massively more successful than Twitter ever was as a public business?
Twitter has certainly been a glowing success at becoming a right-wing propaganda chamber for Musk but as a commercial venture not really. Revenue is down 60% since Musk bought it.
https://www.businessinsider.com/elon-musk-approach-advertise...
The article doesn't mention subscription revenue. I subscribed to X in order to not see ads.
Uh, no, I do not remember how Twitter is massively more successful than it was as a public business. Can you enlighten me?
>Isaacson’s “biographies” are glorified puff pieces. Musk is as unrecognizable in his as Jobs was in his.
i mean, you can also read liftoff and re-entry by eric berger and you will see the same kind of thing being mentioned.
>Both Tesla and SpaceX had teams keeping Musk busy on bs just so that the engineering teams could do their work.
This is Tumblr origin nonsense, especially given that he's allegedly been involved with Engineering work he's not cleared for.
>"According to Isaacson's biography of Musk, Musk relentlessly challenges the existence of every part in Tesla and SpaceX machines."
This removal of surplus-age is common in the automotive industry, and one of the reasons that cars are such an amazing value. It seems like Musk's remarkable ability to achieve cost reductions (at least in the aerospace context) is attributable to his pursuit of vertical integration. Airframers (aeronautical vehicle designers & manufacturer) are bound by the costs dictated by their component suppliers, especially after a configuration has achieved regulatory approval. SpaceX has managed to avoid being 'held hostage' by pseudo-monopoly suppliers.
>This removal of surplus-age is common in the automotive industry, and one of the reasons that cars are such an amazing value.
You say that and then a company like Ford releases this as their EV to show the world that they are competitive with Tesla.
[1]: https://youtu.be/C1dQtlrI7uU?t=70
How does something like this happen despite Ford knowing all the 'secrets' a company like Tesla or the Chinese know? I have a few guesses:
1. Its the structure of the company. In this video the presenter talks a lot about all the hoses and clamp connectors etc. The cooling department thinking they had to stay relevant made sure the car incorporated a design that had all this nonsense.
2. Maybe they didn't put their 'A' engineers on this car. Its plausible: the F-150 is their massive money maker. However this car was supposedly developed under some skunkworks program and yet here we are.
3. Maybe there was sabatoge from elsewhere (suppliers, middle management etc.) You watch a movie like Ford vs Ferrari and while im sure a lot is dramatized, I can't help but think man they were talking about the dysfunction of Ford way back then?!
Then we have Youtube documentaries like this one about the Ford Taurus SHO talking about how they screwed up so much that they had one chance left to get serious...like what? Shouldn't they be serious every day? Thats what the Chinese are doing.
[2]: https://youtu.be/5VTRhCC3gZI?t=56
The presenter further added how they had to ship entire engine blocks to Japan so that they could 'fix' them and unlock 80 more horsepower that Ford just left on the table. If factual, this should be a total embarrassment: You had to send your handiwork to a entity with a better reputation so that they could 'fix' your mess?
[3]: https://youtu.be/5VTRhCC3gZI?t=212
At some point, you have to acknowledge that the naysayers were wrong: Thinking (especially among the short community) was that Tesla had some cool ideas but their implementation was horrific, they couldn't just make up for 100+ years of institutional knowledge that the legacy companies had. The Tesla cars showed some of this thinking: quite poor build quality, poor after sale support, poor parts network. These things improved over the years but still isn't perfect.
But at the same time you have to acknowledge that the legacies suffer from their own problems that dont put them as far ahead as newcomers as you'd think. Sometimes a lot of that institutional knowledge becomes a liability when a paradigm shift occurs.
yes and no. Like you said, automotive and aviation industries are bound by a lot regulatory and path dependent constraints.
Elon's strength is his willingness to pull the plug and transition away from suboptimal solutions. This is bolstered by his willingness to double down.
Imagine if Boeing said "screw all this recertification technical debt for the 737 MAX airframe, we will start fresh. Customers can take it or leave it"
According to a version I heard, Boeing engineering did say more or less just that, at which point Southwest, the near-monopoly in some regions, said something like, "Oh yeah? Then we'll plan to leave it."
And Boeing upper management overruled the engineers.
Color me skeptical.
There was nothing wrong with the MCAS concept. The implementation of it, however, wasn't very good.
Unfortunately, two of the 3 crews did not understand the runaway stabilizer trim procedure. The 3rd crew did, and landed safely, and the media never reports on that.
The runaway stab trim procedure is a "memory item", meaning pilots shouldn't need a checklist to deal with it.
> The runaway stab trim procedure…
But doesn’t apply to MCAS because the symptoms and recovery procedures are distinct.
The MCAS system wasn’t documented, pilots weren’t trained on it, it didn’t indicate anything distinct in the cockpit, and it could rapidly put the plane into an unrecoverable attitude where pilots no longer had the physical strength to overcome the forces involved.
I know how the stab trim system works. I worked on it (for the 757) for three years.
Yes, it applies to MCAS.
> the symptoms and recovery procedures are distinct
Nope. MCAS failure manifests itself as runaway trim, and the emergency procedures for it are exactly what is needed to recover from it.
1. the stab trim switches override the MCAS signals. Override. That means the pilot can trim to normal using the column mounted trim switches. The column switches will power the trim back to normal. No physical strength is required.
2. there's a "stab trim cutoff" switch on the console. That turns off the trim system. MCAS cannot bypass it.
The proof is the 3rd MCAS incident. The pilots trimmed it back to normal, and turned the stab trim system off.
That's all they had to do.
This is supposed to be a "memory item". The other two crews did not remember the memory item. Boeing even sent out an Emergency Airworthiness Directive reiterating this information. It was ignored by the EA pilots, who did everything wrong (including overspeeding the airplane at full thrust).
The narrative you wrote is the typical one in the mass media, which is utterly wrong. The proof of that is they ignore the 3rd incident which didn't fit the narrative.
I've talked with two 737 pilots about this. They agree with me, though I knew I was right anyway.
Food for thought: ever wonder why the stab trim cutoff switch is in a prominent place on the center console in easy reach?
You just took Boeing adding a secret system that can cause a plane to crash and then blamed the pilots who were unfortunate to be a victim of malfunctioning sensors and then put all the blame on them because pilots who didn't want to die inside a deathtrap aircraft figured out how to avoid their own death the moment they realized that the MCAS crashes were not an isolated incident?
What exactly are you accusing the pilots involved with the accident of? That they had some perverse incentive to die?
> put all the blame on them
Nope. I wrote: "The implementation of it, however, wasn't very good"
> What exactly are you accusing the pilots involved with the accident of?
Not following the runaway stabilizer trim procedure. This is supposed to be a "memory item", meaning a checklist is not required.
There were 3 MCAS incidents:
1. crew trimmed to normal with the thumb switches, then turned off the trim system. Flew the rest of the flight, landed safely.
2. crew trimmed it back to normal at least 11 times (if I recall correctly) and never turned off the trim system. Crashed.
3. Boeing Emergency Airworthiness directive was sent to all MAX pilots. In a nutshell, it says to restore normal trim using the thumb switches then turn off the trim system. EA pilots instead turned off the trim system while the airplane was pointed down at full throttle. Crashed.
The two 737 pilots I talked to about this both asserted pilot incompetence.
Personally, I assign half the blame on Boeing and the other half on the pilots. Flying is not a joke. Not paying attention to an Emergency Airworthiness Directive is not acceptable.