[HN Gopher] Indian startup 3D prints rocket engine in 72 hours
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Indian startup 3D prints rocket engine in 72 hours
Author : pseudolus
Score : 316 points
Date : 2024-06-13 11:02 UTC (11 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| instagraham wrote:
| Among world-firsts that happen in contemporary India, this is
| probably one of the coolest.
| passion__desire wrote:
| There is a veritasium video on rocket 3d printing.
| edm0nd wrote:
| For the curious: https://www.youtube.com/watch?v=kz165f1g8-E
| mlindner wrote:
| It's not a world first. It's an industry standard in tact.
| greekanalyst wrote:
| That's super cool.
|
| India has enormous potential and it is amazing to witness the
| rise of its tech scene.
| mlindner wrote:
| I wouldn't jump to praise so quickly. Additive manufacturing
| (aka 3D printing) is standard in the industry and the time is
| dependent on the size (and to some extent the mass) of the
| engine.
|
| They then further claim you don't need to do any post-
| manufacturing qualifications, which is absolute nonsense. So
| it's either misreporting or it's an indication of Indian
| incompetence/lying.
| ab8 wrote:
| I wonder where Indian incompetence/lying falls on the Elon
| scale.
| alephnerd wrote:
| > feature eight engines in total and able to carry a 300-kilogram
| payload to an altitude of around 700 km. The launch vehicle used
| in May's test was only 6 meters tall
|
| Significant military implications as well [0].
|
| There is a significant spy-sat race going on in the region right
| now [1] with China, India, UAE, Saudi Arabia, US, Japan, South
| Korea, North Korea, Russia, Iran, Israel, etc all investing in
| capabilities in the region.
|
| Also has an impact in enhancing India's Ballistic Missile
| strategy used to combat a two-front war [2], because Missiles are
| to Indian military strategy what Drones are for Chinese military
| strategy.
|
| Also highlights how the India-US relationship is built by the
| Indian-American diaspora. The VC who funded Angikul is Anand
| Rajaraman - the Stanford professor who started "Big Data" with
| Ullman, was one of the earliest investors in Facebook, and lead
| Amazon Marketplace after getting acquired by Amazon early in it's
| history (Marketplace was originally an Indian e-commerce startup
| called Junglee).
|
| As India gets richer, and America's immigration system gets more
| and more rickety, a reverse brain and capital drain has started
| to form, much like with Chinese Americans in the late 2000s.
|
| [0] - https://www.deccanherald.com/opinion/agnikul-showcased-
| more-...
|
| [1] - https://asia.nikkei.com/Politics/Defense/China-and-India-
| lea...
|
| [2] - https://www.usiofindia.org/publication-journal/Evolution-
| of-...
| fallingknife wrote:
| > America's immigration system gets more and more rickety
|
| It's completely insane that we allow mass migration of people
| with no money and no skills and make it incredibly difficult
| for the most valuable immigrants to get in.
| nordsieck wrote:
| > It's completely insane
|
| It makes perfect sense when you understand the principal-
| agent problem and the current political landscape.
|
| https://en.wikipedia.org/wiki/Principal%E2%80%93agent_proble.
| ..
| panick21_ wrote:
| If the policy was the opposite you could also argue that.
| Its basically a fundamental problem of government, whatever
| the outcome.
|
| You have to be way more specific when you want to actually
| be insightful about the topic.
| pjc50 wrote:
| > we allow mass migration of people with no money and no
| skills
|
| You don't? There's no visa for that category.
| teitoklien wrote:
| you do, if you have sanctuary cities and entire states
| openly claiming they will not arrest people who break
| immigration law, it reduces the ability of USA to actually
| pass policies to take in more skilled immigrants who'll be
| a net benefit to America as a whole.
| pjc50 wrote:
| Like the War On Drugs, the human cost, violence, and
| intrusiveness of enforcement is worse than the alleged
| problem. The much-vaunted localism of America lets states
| and cities decide that it's not a problem for them to
| allow people to live there, and they don't want to help
| the big bad Federal government disrupt that.
|
| (it's still no picnic being in that category, unable to
| register for social security or even take an internal
| flight)
| teitoklien wrote:
| World isnt some amazing la la land, I hope people who
| break laws to immigrate to America, will continue having
| the same sympathies towards you, when they become
| majority, and start dominating over you with their
| culture.
|
| It feels bad to say this, but to build a good well
| integrated state, integration is key, you cannot
| integrate people into a society, if you cannot even
| control the immigration rate. You can't just let people
| come to your country illegally, setup shop, and then tell
| everyone 'Cant do anything about it folks'.
|
| The human cost is paid in everything, the cost americans
| need to worry about, is whether the safety and future
| prospects of americans is safeguarded, not of people who
| break laws to illegally immigrate.
|
| It's like having sympathy for a next door neighbour child
| who is uncared for, and serving him/her food, while
| you're own child cries and starves to death.
|
| America isnt a country, with limitless resources, and
| enough food,housing,healthcare to feed everybody, stop
| treating it like it.
|
| Also, I'm not sure the people who arrive here illegally
| are as ready to integrate with America's culture, as some
| americans are ready to integrate with illegal migrants.
|
| I understand life is cruel, and maybe america should even
| do good things for it, but not at the cost of watching
| americans starve to death, veterans getting overdosed on
| the streets wishing after years of suffering to just die
| and be at peace, and watching them not being able to help
| them, because our resources are too stretched, Charity
| starts at home. Even the people who migrate illegally
| here, they'll help their own first, before even sparing
| one thought towards you.
|
| One needs to be realistic about certain things, it's
| perfectly doable to protect your own borders, Singapore
| does it against Malaysia, India does it against Pakistan
| and Bangladesh (big borders), China does it against
| neighbouring countries, most Asian countries can protect
| their own borders.
|
| Why can't america?
| troyvit wrote:
| > I hope people who break laws to immigrate to America,
| will continue having the same sympathies towards you,
| when they become majority, and start dominating over you
| with their culture.
|
| I don't know how many folks around me broke the law to
| immigrate to America, but whether or not they broke the
| law to come here they faced a lot of racism, classism,
| and suspicion. I've been in the same area for about 20
| years, and if I'm not a minority in my neighborhood it's
| close. It's the immigrants who are kind to me, help me
| keep my house secure, and trade goods and services with
| me. They even help me practice my awful Spanish with
| them. So in my case, yeah it's working out.
|
| > America isnt a country, with limitless resources, and
| enough food,housing,healthcare to feed everybody, stop
| treating it like it.
|
| America doesn't have limitless resources, but with 5% of
| the world's population it uses 25% of the world's
| resources [1]. To anybody's eyes that's going to look
| limitless.
|
| I think simple laws of diffusion say that people are
| going to go where the resources are available. Whether
| it's politically tenable doesn't matter, this is human
| nature since we started walking.
|
| [1] https://www.re-sources.org/2020/05/online-lesson-
| material-wo...
| chasd00 wrote:
| If you don't mind sharing, i'm curious to know where you
| live. I live in North central Oak Cliff which is a large,
| predominantly hispanic, area consisting of multiple
| neighborhood just SSW of downtown Dallas. In my
| neighborhood there's a local Mercado that i can walk to
| for small things, i speak enough Spanish to manage but
| I'm eyed with suspicion from when i go in to when i
| leave. My wife is a HS teacher with about 25% of her
| students being undocumented. They use a bus service in
| Oak Cliff to freely move back and forth to Mexico, i'm
| not sure how that works but that's what they use.
|
| My son's middle school is a DISD public magnet in a
| wealthy area called Preston Hollow. The middle school is
| probably 85-90% hispanic and despite my kids being 1/2
| Mexican they have faced enough racism and abuse that my
| wife and I have had multiple meetings with the
| administration to address it. African American kids face
| it even worse. One other anecdote, when my kids were in
| elementary some of their calsses were taught in Spanish
| because my kids and one other were the only ones who
| spoke English. The teachers, who barely spoke English
| themselves, got in trouble for that. Ironically, if you
| want true diversity in Dallas schools you have to pay/be
| admitted to the elite private schools.
|
| All this to say, in my experience, neighborhoods
| consisting of mostly undocumented immigrants and cities
| welcoming of undocumented immigrants aren't that great...
| unless you're an undocumented immigrant.
| fwip wrote:
| If 20 of the kids spoke Spanish and 2 of the kids spoke
| English, doesn't it make sense to teach the course in
| Spanish? Why would the teachers get in trouble?
| adventured wrote:
| For now at least half of the US is pretending there
| aren't 40-50 million illegal immigrants in the US, even
| though the country is overflowing with undocumented
| persons and it has become an enormous problem. Every mid-
| size town and above has a lot of illegal immigrants
| today, whereas 20 years ago there were few. So if you
| start switching public school systems over to Spanish
| because entire schools are now filled with illegal
| immigrants, or children of illegal immigrants, it's going
| to get a lot of unwanted attention. Plus it reveals that
| the US is fracturing rapidly. Whereas English is
| drastically more valuable than Spanish economically, the
| US is developing a large population base that does not
| speak English and it's quite bad for the country's
| cohesion and economic outcomes.
|
| I'm seeing this firsthand. Where I live in a mid-size
| university town, 20-30 years ago there was practically
| zero illegal immigration, undocumented persons. It was
| fairly unheard of. Now there are a vast number of
| Spanish-only speaking illegal immigrants. My apartment
| complex in the span of a few years has become 3/4 illegal
| immigrants that only speak Spanish, almost entirely young
| adult males. They harrass anyone that isn't Hispanic and
| have tried to push all other tenants out of the complex.
| The police are called frequently for violence issues, and
| being uneducated young adult males they drink heavily and
| trash the place constantly.
|
| It can't be fixed either. If you just remove the gigantic
| base of illegal immigrants GDP will plunge by at least
| 10%. Nobody will do that. There is no path forward other
| than chaos. No serious immigration reform will get passed
| near-term.
| fallingknife wrote:
| Of course when the federal government decided to let
| millions of them in and the local government in Texas
| decided that it was a problem for them and decided to
| enforce it themselves, all those people who are so much
| in favor of local control when it comes to "sanctuary
| cities" suddenly lost their shit.
| fallingknife wrote:
| They are allowed in without visas
| pjc50 wrote:
| Not having a visa is the opposite of "allowed".
| fallingknife wrote:
| No. Being kicked out is the opposite of allowed.
| sn41 wrote:
| It's quite understandable, imho. Immigration is being allowed
| precisely for cheap labor, especially when citizens are not
| prepared to go through the extra hardship - for example, I
| remember reading that the fatalities when the bridge fell in
| Baltimore around 1 am, were all immigrants, all on duty at
| that hour.
|
| For specialized labor, there is always a question of possible
| espionage and back-channel tech transfer. This is not so much
| perhaps for India as opposed to other technological rivals,
| but it may be one of the considerations in the immigration
| policy being counterintuitive.
| pjc50 wrote:
| > fatalities when the bridge fell in Baltimore
|
| As an example of how strict immigration policy is, the crew
| were made to stay on the boat throughout, including while
| parts of the bridge were blown up.
| axus wrote:
| I'd inferred that it was the company keeping them there,
| after hearing stories like this:
|
| https://www.cbc.ca/radio/asithappens/as-it-happens-
| monday-ed...
|
| This article goes into the actual reasons, the visas only
| came into play during the second month:
|
| https://www.cnn.com/2024/05/18/us/baltimore-bridge-dali-
| ship...
|
| Basically the company would get in trouble if the crew
| left, and they are too cheap to hire replacements, so
| they threaten them.
| qp11 wrote:
| pfft people who want to find a way around what anyone
| "allows" will do so. To desperate people rules dont
| matter.
|
| There are more than 50 countries right now standing with
| begging bowls outside the IMF cause their economies have
| no hope of growing without help. As long as that list has
| no hope of shrinking, people who live there and recognize
| that reality, are going to find ways to get out by hook
| or crook.
|
| Immigration is a symptom of growing global inequality.
| Without inequality reducing no rules or walls are going
| to stop the incoming waves.
| nathan_compton wrote:
| I wouldn't defend america's immigration system (in my opinion
| the world should be borderless and you should be able to vote
| in any location where you can demonstrate that you've
| performed work for a wage or something like that), but if
| anyone should be allowed to seek labor by moving freely, it
| is the unskilled, who are already tremendously disadvantaged
| by globalization. Skilled labor is unlikely to be
| tremendously impoverished by being unable to move to the
| absolute optimal location.
|
| In other words, one could say its insane that we draw
| imaginary lines on paper and then confine human beings to
| those lines based on the accident of their birth location.
| IG_Semmelweiss wrote:
| Those lines are not imaginary per se. It means that the
| people living within those imaginary lines have come
| together with similar ideals and unity, arrived by many
| years of co-operation, to bestow certain rights and
| privileges to their fellow neighbors. Those rights were
| paid in blood, sweat and tears.
|
| The reason people organized as tribes matters. Its part of
| our very nature. And those tribes also respected imaginary
| lines. Even animals respect some imaginary lines.
| Eventually, some may be accepted in the tribe. But no one
| would just walk in to the tribe. Its not how nature works.
| nathan_compton wrote:
| Hardly. The lines are basically drawn by aristocrats of
| one kind or another and the rest of us have to deal with
| it. They are expressions of _power_ and very little else,
| and mostly not the power of the people. The rights paid
| for in blood, sweat, and tears, as you say, were wrenched
| from the hands of the kinds of people who draw borders
| and consist entirely of statements that are borderless
| assertions of the value of _human beings_ , not
| _citizens_. You may be right that there is some kind of
| fundamental tribal mentality in human beings, but that
| doesn 't mean that enshrining that reality in law or even
| nurturing it is morally right. The idea that borders
| benefit the common person better than, for example, a
| system which genuinely respected the dignity and right of
| human beings regardless of their geographical
| coincidences, is bullshit.
| hindsightbias wrote:
| valuable immigrants are going to take my jerb and not flip my
| hamburger, pick the crops or mow my lawn.
| nordsieck wrote:
| > Also has an impact in enhancing India's Ballistic Missile
| strategy used to combat a two-front war [2], because Missiles
| are to Indian military strategy what Drones are for Chinese
| military strategy.
|
| Almost no one uses liquid fueled Ballistic Missiles any more (I
| think China is the only one) because they are so operationally
| terrible.
|
| The eventual rocket sounds like it's a hair larger than
| RocketLab's Electron. Which is struggling to reach
| profitability after being in its segment for 7-8 years mostly
| without peer competition. Largely thanks to SpaceX's
| transporter (and now bandwagon) missions sucking most of the
| volume out of the market.
|
| Making a working rocket is undoubtedly an amazing
| accomplishment. But at the same time, I really wish that
| companies stopped making small-lift rockets. There's just no
| way for them to work financially.
| alephnerd wrote:
| > Almost no one uses liquid fueled Ballistic Missiles any
| more (I think China is the only one) because they are so
| operationally terrible.
|
| India does as well as China.
|
| But they are cheap! Very cheap. Read the 3rd article I linked
| - it's the actual Indian government strategy around BMD.
| nordsieck wrote:
| > India does as well as China.
|
| > But they are cheap! Very cheap. Read the 3rd article I
| linked - it's the actual Indian government strategy around
| BMD.
|
| The only place that liquid rockets are specifically
| mentioned:
|
| > Scientists are also working towards making interceptors
| used in both layers operate on solid fuels. This is because
| chemicals in the liquid fuels corrode the fuel storage
| tanks easily. Therefore, most of the missiles are not kept
| in a 'ready-to-fire' mode. Also, it takes a minimum of
| three to four hours to fill the liquid fuel in the
| missile,9 a hardly acceptable scenario wherein precious
| time will be lost in case of an emergency.
|
| It seems pretty clear that:
|
| 1. This particular rocket has no military application
| because the rockets that India uses use hypergolic
| propellant (presumably UDMH and NTO), while the planned
| rocket uses LOx and RP1, which are cryogenic propellants
| (well, at least the LOx is).
|
| 2. India is pretty clearly trying to move away from liquid
| fueled rockets because, as I said in my previous comment,
| the operational aspects are really terrible.
| philipwhiuk wrote:
| > But at the same time, I really wish that companies stopped
| making small-lift rockets. There's just no way for them to
| work financially.
|
| Making a small launch vehicle is seen as necessary to attract
| the level of funding needed for a medium or heavy lift launch
| vehicle
| nordsieck wrote:
| > Making a small launch vehicle is seen as necessary to
| attract the level of funding needed for a medium or heavy
| lift launch vehicle
|
| I get that.
|
| But it seems like every VC on the planet had the same idea
| at the same exact time because there's like 50+ small lift
| rockets in various stages of development. And approximately
| 0% of them have a shot at profitability.
|
| I have real doubts that any of them that aren't backed by a
| nation-state will be able to fund raise and survive long
| enough to build a medium lift rocket on the back of their
| experience.
| pm90 wrote:
| This is amazing. Strap several of those engines with a control
| system of some sort and you can basically launch a wide variety
| of payloads.
| philipwhiuk wrote:
| > control system of some sort
|
| Control of multiple engines is non-trivial. You get fun stuff
| like plume interactions between the engines.
| Etheryte wrote:
| > The machine also automatically outputs a report that details
| any deviations during printing, removing the need for
| postfabrication qualification.
|
| Anyone who's previously worked with 3D printing knows that this
| simply does not pass any kind of a sniff test. Both preventing
| and detecting internal defects is one of the, if not the hardest
| problem in 3D printing. There are many large companies trying to
| find ways to reliably solve just this problem alone. Saying that
| this method doesn't require any checks after production is simply
| false.
| guax wrote:
| Titan submersible sound detection system vibes.
| nathan_compton wrote:
| Exactly what I thought.
| cjbgkagh wrote:
| I'm not sure how many people know about their 'sound
| detection system'.
|
| Carbon fiber is a fickle beast and is prone to such failures
| so that alone worried me, but it was incredible for me to
| learn that they expected some sort of early warning from
| cracking.
| ladams wrote:
| Do you have a link? Google just gives results about the US
| Navy detection of the implosion...
| azornathogron wrote:
| https://www.businessinsider.com/oceangate-2020-boasted-
| incre...
| lucianbr wrote:
| https://www.youtube.com/watch?v=6LcGrLnzYuU
|
| As I remember he talks about the sound detection thing.
| NortySpock wrote:
| https://www.wired.com/story/titan-submersible-disaster-
| insid...
|
| Recent one-year-lookback story by Wired.
| raverbashing wrote:
| Well there were probably some early warning signs
|
| The problem is that warning sign comes at around 10ms or
| less before the actual disaster
| rvnx wrote:
| If it would be a Tesla, just enough time for the auto-
| pilot to disengage and claim it was the fault of the
| user.
| ETH_start wrote:
| Tesla autopilot is not supposed to be unmonitored, so any
| accidents under its control are entirely the fault of the
| driver. If a driver disengaged 0.1s before impact, they
| were derelict in their driving.
| abduhl wrote:
| OSHA has a nice pamphlet regarding hazard identification
| and hazard controls. The least effective method of
| protecting workers is to put the risk on the worker to
| protect themselves. Your view has a similar vibe to "well
| they weren't wearing their hard hat and so it's their
| fault," a view that has been rejected across the board
| for safety in favor of the view that even letting the
| situation get to that point is a failure.
|
| https://www.osha.gov/sites/default/files/Hierarchy_of_Con
| tro...
| ETH_start wrote:
| Driver control IS making the driver responsible, by
| definition. Tesla is legally required to put the driver
| in control.
|
| This is a driver assist program. There is no way such a
| program, that is subordinate to the driver and depends on
| the driver being in control, can protect the driver from
| not doing their part, and driving.
| sjsdaiuasgdia wrote:
| Shame about the "Full Self Driving" branding
|
| They can put whatever disclaimers in the manual but their
| branding is giving a different message. It's a message
| Tesla wants the customer to hear: "sit back and relax,
| the car drives for you."
|
| The branding does not communicate that the driver needs
| to be just as aware and engaged as they would be if they
| were driving on their own, and be ready to take control
| of the vehicle at any moment.
|
| Compare this to GM's "Super Cruise" branding. The message
| I get from that is "cruise control, but better." Cruise
| control is a long established feature, drivers have
| plenty of experience with it, and they know that it is
| definitely not going to drive the car itself. They know
| they're still going to have to pay attention because the
| car is going to do _some_ of the driving tasks but not
| _all_ of them. The car is making no implicit or explicit
| claim that it will drive for you.
|
| "Full Self Driving" and related features like "Summon"
| make implicit claims in how they're named and presented.
| The driver absolutely has responsibility but Tesla is
| trying to play both sides of the coin with their branding
| vs their actual liability.
| abduhl wrote:
| First, Tesla is not legally required to put the driver in
| control - they are free to indemnify the driver
| completely and shoulder all of the liability themselves.
|
| Second, who do you think was ultimately the one at fault
| for the excessive radiation doses caused by the Therac-25
| machines: the machine technician operating the machine or
| the machine manufacturer? If it isn't the technician then
| I don't understand your argument because you can just
| find/replace every instance of driver in your post with
| technician.
|
| https://en.wikipedia.org/wiki/Therac-25
| gridspy wrote:
| Therac-25 is more like a stuck accelerator pedal. The
| operator did not command the machine to deliver too much
| radiation, that happened outside their control.
| abduhl wrote:
| And you think that a driver commands their Tesla to run
| into an object when they enable autopilot or FSD?
| gridspy wrote:
| One is a failure to act as an agent - to control the car
| and make decisions. Another is a failure to even be a
| reliable tool - to do what the operator commands. Very
| different.
|
| Creating Agents is a lot harder.
| lowkeyoptimist wrote:
| If a driver is using any driver assistance feature they
| need to be paying attention all the time. Not only is it
| stated in all vehicle manuals, it is the intelligent way
| to use the features given that automated driving is still
| far from perfect.
|
| Your analogy makes no sense given that the risk is always
| on the driver whether there are driver assistance
| features or not.
| gridspy wrote:
| Unfortunately it is very difficult to remain vigilant
| when the automated system seems to be doing a great job.
| Eventually you will become distracted.
|
| Even in accident cases, remember that the Teslas involved
| are not new - they have had dozens or hundreds of
| successful drives before the accident.
| toss1 wrote:
| This is true, but it also falsifies Tesla's naming,
| promotion, abd advertising of the capability as "Full
| Self-Driving".
|
| ("Self-Driving" alone could be reasonable in certain
| contexts, but insisting on "Full Self-Driving" is a flat-
| out lie in plain language. Saying " Alan is fully capable
| of driving the car." means that he requires zero
| monitoring and/or intervention; same for the "Fully..."
| phrase.)
| ETH_start wrote:
| What the name implies if interpreted without any context
| pales in comparison to the repeated and explicit
| instructions and warnings given to the driver that
| clarify that the driver should always be in control.
| toss1 wrote:
| Yup.
|
| It's "we'll take the profits from selling it as something
| that it is not.".
|
| While simultaneously they take every step to ensure that
| when things go wrong when it inevitably turns out to NOT
| be what they claimed, the entire burden and
| responsibility is not on them, but on you.
| mynameisvlad wrote:
| You don't just get a pass, especially not when you
| actively are promoting it as soon(tm) being able to drive
| you without any input whatsoever. Robotaxis and the like
| have been promised for years now, it's not like Tesla
| isn't actively claiming the technology is basically
| around the corner.
|
| In short, saying it's "Full Self Driving (Supervised)" is
| not really enough.
| shepherdjerred wrote:
| You're completely right, but unfortunately people place
| too much trust in it.
| 6510 wrote:
| It reminds me of the data entry days. You can have
| someone type a million table rows into a form and catch
| all typos but if you give the same person the same data
| and the same time without having them type it they find
| non of them.
| lukan wrote:
| Is there data, that indicates Tesla did this, or
| something like this?
| lesuorac wrote:
| Kind of? Autopilot has a habit of disengaging right
| before crashes [1]; which may not be a bad thing, your
| seat belt also has a habit of not being adjustable in a
| crash (dunno if an ICE engine will turn off).
|
| Mix that with Elon had a habit of commenting on crashes
| [2] to keep good marketing about FSD. And like who cares
| if it was "Auto lane control" vs "Autopilot" that let
| somebody drive the car from the passenger seat but Elon
| made sure to let everybody know "Autopilot" wasn't
| engaged.
|
| [1]: https://www.motortrend.com/news/nhtsa-tesla-
| autopilot-invest...
|
| [2]: https://www.consumeraffairs.com/news/elon-musk-says-
| autopilo...
| Dylan16807 wrote:
| Your second link makes it clear that no version of self-
| driving was on anywhere near that particular crash, so
| that does not support the above comment at all.
|
| If the only true part is that the system disengages at
| some point, then "kind of" is much too generous for that
| kind of rumor-mongering.
|
| But if I ever see some real proof I'll spread it far and
| wide.
| cjbgkagh wrote:
| I don't know how many 'test to failure' tests would have
| been required before I would have any confidence in the
| models but probably so many tests that the titanium
| alternative would have been far cheaper.
|
| The other problem is that it cracks all the time and they
| get louder as they get deeper, so it's not just if it
| cracks it is if it cracks enough or more than expected.
| Which straw will break the camels back. It is just such
| an insanely awful metric.
|
| On the hypothetical assumption that I had some faith in
| the models at what point will I have the life or death
| fight over whether or not that last loud crack was
| statistically significant.
| wongarsu wrote:
| There were plenty of early warning signs. In a previous
| dive back in 2019 they had professional submersible
| designer Karl Stanley on board, who later wrote an email
| to OceanGate about the worrying cracking sounds he heard.
|
| > "What we heard, in my opinion ... sounded like a
| flaw/defect in one area being acted on by the tremendous
| pressures and being crushed/damaged," Stanley wrote in
| the email, a copy of which has been obtained by CNN.
|
| > "From the intensity of the sounds, the fact that they
| never totally stopped at depth, and the fact that there
| were sounds at about 300 feet that indicated a relaxing
| of stored energy /would indicate that there is an area of
| the hull that is breaking down/ getting spongy,"
|
| It's more impressive that the sub continued to work while
| giving warning signs for 4 years.
|
| https://abc7.com/titan-submersible-2023-incident-titanic-
| oce...
| sjm-lbm wrote:
| They seem to have totally recreated the hull using a
| different manufacturing method in late 2020/early 2021:
| https://www.wired.com/story/titan-submersible-disaster-
| insid...
|
| They seem to have run fewer tests on the new hull,
| though. From the outside, it looks like one of the
| lessons they learned from earlier tests was that tests
| can create bad news, so if you're optimizing for the best
| reports back to investors you should stop running tests.
| numbsafari wrote:
| If they're not doing post fabrication validation, then the
| passengers are...
| drlemonpepper wrote:
| what's wrong with testing in prod? /s
| numbsafari wrote:
| Nothing. Always Be Testing.
|
| But _only_ testing in prod is bad.
| surfingdino wrote:
| ... test dummies.
| vasco wrote:
| If any system could measure its own signal to noise accurately,
| it wouldn't have any noise in the first place.
| sobellian wrote:
| This is a "truthy" statement that sounds right but is, in
| fact, false. Radio systems have an easily measurable SNR, but
| the noise cannot be eliminated.
| vasco wrote:
| You can measure is from outside the system itself if you
| know the original signal. Of course its possible to measure
| the noise externally if you know what was transmitted.
| sobellian wrote:
| AFAIK this is incorrect. There exist modulation schemes
| where the received signal power is evident. For Wifi the
| signal is usually > 10-100x the noise floor and it is
| modulated with phase-shift keying. So there is no
| technical problem with seeing a noise floor, then
| receiving a much larger signal with constant envelope and
| calculating an SNR.
|
| ETA: Just to sharpen the point, this is clearest when
| considering digital noise and error correction. It is
| easier for error correction codes to indicate a corrupted
| message than it is to provide the correct message.
| xxs wrote:
| You may go further and say the rocket would be built on a
| proper rocky foundation.
| surfingdino wrote:
| I too am doubtful. The market is littered with failed 3d
| printed products, all failed because the designers know nothing
| about real-life product design or because their deigns are too
| brittle or melt too easily in heat.
| metal_am wrote:
| It might sound a little wild, but a huge amount of research has
| been put into getting metal AM parts to be "born qualified."
| L-PBF is getting to be a fairly mature technology.
| NortySpock wrote:
| To steelman the argument, maybe they meant "the monitoring
| system is good enough at catching defects that if none are
| reported, the engine will probably pass an all-up hotfire test
| of the engine".
|
| Of course you could do a water or air-pressure leak test on the
| plumbing pretty easily, and you would likely do that on the
| first 30 engines...
|
| But if you have confidence in your build process, maybe the
| juice isn't worth the squeeze on (say) a direct contact
| ultrasound void check on every square millimeter of the part.
|
| It's all about "how expensive is it to run the test" vs "what
| is the likelihood the test catches an issue" vs "what's the
| cost of failing while everyone is watching?"
|
| Same reason SpaceX went from dry-dress-rehersals to wet-dress-
| rehearsals to separate-static-fire-before-launch to hold-down-
| for-three-seconds-before-launch... The hold-down -before-launch
| is an integration test that covers everything the previous
| tests do, so eventually you can start removing redundant tests.
| sandworm101 wrote:
| >> maybe the juice isn't worth the squeeze
|
| In rockets/aerospace, where the failure of any one of a
| thousand different parts means instant disintegration, checks
| are always worth the squeeze. Everyone talks about building
| rockets on the cheap and accepting a slightly-higher failure
| rate, but in reality that doesn't work. Even a tiny increase
| in component fault rates translates to total mission failure
| once multiplied across thousands of vital parts. The answer
| isn't to not check but to find ways to more efficiently and
| more thoroughly check each part. This is only more true if
| one considers reusable rockets where components will be
| expected to participate in multiple launches.
| giantrobot wrote:
| > In rockets/aerospace, where the failure of any one of a
| thousand different parts means instant disintegration
|
| To make matters worse the failure modes don't only affect
| the launch vehicle itself. A failure of a rocket likely
| means a total loss of the payload. It also runs the risk of
| damage/loss of the launch pad, support structures, and
| hapless down range victims.
|
| Rockets contain a significant amount of stored chemical
| energy, enough to get the payload mass into a stable orbit
| of the Earth. If you release all of that energy at once as
| an explosion it will cause a significant amount of damage.
| Rockets aren't something to goof around with and make
| assumptions about safety.
| throwitaway222 wrote:
| Well, if you build it robust enough, you can test less. Not
| saying testing is worthless, but sometimes a one-piece that
| used to be 45 pieces held together by rivets is just, much
| much more resilient.
| chfalck wrote:
| It's a bit of chicken and egg to know if you built it
| robust enough without meticulous testing of your
| robustness
| jes5199 wrote:
| this might be 20th-century thinking. if you can build
| enough copies of a rocket cheap enough, maybe
| disintegrating a bunch of them isn't a showstopper
| lesuorac wrote:
| Who pays when the payload disintegrates?
| nordsieck wrote:
| > if you can build enough copies of a rocket cheap
| enough, maybe disintegrating a bunch of them isn't a
| showstopper
|
| The problem with that idea is that you won't be legally
| allowed to launch again until you root cause and fix the
| failure, which can take months (or years if you're Blue
| Origin). Also, your insurance rates tend to go up a lot
| when your rockets blow up regularly, which tends to push
| customers away.
|
| In practice it doesn't work.
|
| Notes: Astra said they were going to pursue this
| strategy. It was not well received by potential customers
| and they basically had to walk it back.
| schmidtleonard wrote:
| Doesn't work? It seems to be working great for the
| industry leader.
| nordsieck wrote:
| > Doesn't work? It seems to be working great for the
| industry leader.
|
| What are you talking about? SpaceX's Falcon 9 is arguably
| _the most reliable_ rocket ever made. They 've launched
| hundreds of times in a row without failure.
|
| If your point is that they're blowing up Starship
| prototypes, well... they're in the middle of a
| development program and they're not flying customer
| payloads.
| locococo wrote:
| from the rocket perspective, sure, but not so much from
| the perspective of your cargo.
|
| In many cases the cargo is more precious than the rocket
| so you need reliable rockets.
| ruined wrote:
| this works for munitions, but not for payloads that
| anyone cares about.
| switchbak wrote:
| Not sure exploding rockets on their launch platform is
| such a good thing when they're carrying a bunch of highly
| explosive / fragmentary warheads (in addition to the
| rocket itself, which is plenty dangerous).
|
| Unless this was something like a cruise missile dropped
| at altitude where a failure isn't a big deal.
| gridspy wrote:
| I'm sure even in this case, risking the air-frame of the
| bomber or friendlies on the ground below is not ideal.
| Bear in mind cruise missiles are usually launched from
| friendly territory.
|
| Also, failures might reduce the accuracy of the missile,
| leading to potential civilian causalities.
| sandworm101 wrote:
| >> cruise missile dropped at altitude where a failure
| isn't a big deal.
|
| If failure isn't a big deal, then the weapon should no
| have been used. An ALCM costs millions. The destruction
| it causes is part of a larger battle plan. Should it not
| work properly then friendly forces may die. Should it
| work properly then enemy forces may die. The
| effectiveness of such a weapon is never not a big deal.
| fullspectrumdev wrote:
| The issue isn't the rocket: it's what you have affixed to
| it (the payload).
|
| The rocket itself is purely a delivery system for a
| payload after all.
| sandworm101 wrote:
| >> maybe disintegrating a bunch of them isn't a
| showstopper
|
| But it isn't about destroying a bunch of them. Cut
| corners on checks and you very quickly blow up all of
| them. Any slight increase in the failure rate of
| individual parts, saving a few pennies, multiplies
| exponentially across the entire rocket into total system
| failure. So the money-saving approach is actually to test
| test and retest, to cram down the failure rates so low
| that the cumulative rate become acceptable (about 1%).
| risenshinetech wrote:
| Right, because as one of your rocket customers, I'm
| totally fine with you disintegrating my one-of-a-kind
| payload
| timerol wrote:
| > checks are always worth the squeeze
|
| This is simply inaccurate. You can spend months and
| hundreds of millions of dollars running scanning electron
| microscopes over all of your parts - no one does this,
| because it's not "worth the squeeze". The question is where
| to draw the line, and I have no idea what your opinion is
| there.
| treflop wrote:
| My dad works in aerospace. In no field or world does anyone
| actually check every little part.
|
| You create a process, you test that process so that you
| understand its limits, and then you make sure to follow
| that process.
|
| Now I don't know if 3D printing rocket parts actually works
| and I have my doubts but this startup is currently testing
| the process and they will figure out its limits. That's the
| whole point of R&D.
| Etheryte wrote:
| For context, 3D printing rocket parts is incredibly
| common, even student teams often use printed nozzles and
| such. The linked article is about printing a whole engine
| as a single piece, which is a different beast.
| la64710 wrote:
| Yes and innovation curve tends to go down in large companies
| because of barriers which a startup is not bounded by. This is
| how future big companies are created.
| skybrian wrote:
| I'm curious about why that is. Naively, it seems like printing
| layer by layer would allow for a lot of inspection. Maybe even
| photograph each layer as you go?
|
| And then test and go back to see what kinds of defects were
| apparent in the photos.
| dotnet00 wrote:
| It's just that it's very easy for deviations from what the
| sensors see to occur. In traditional 3d printing, this can be
| stuff like a sensor switch wearing out, maybe physically
| moving slightly, being temperature sensitive, maybe the frame
| has changed shape slightly due to heat, moving the sensor a
| little, maybe something in the microcontroller happened to
| cause a slight delay in reading the sensor, or looseness
| developing in the motion system, or something being slightly
| out of alignment, or some component in the extrusion system
| experiencing momentarily higher friction and so on.
|
| The layers are really thin, so manually inspecting them would
| slow down the printing process drastically. Then, ultimately,
| what even can you do if there's a defect? The layer has been
| laid already. If material is missing somewhere, you could
| have the machine go back and add it, but if there's excess
| material somewhere, or it's in a form that the machine can't
| fix, there's not a lot to be done, particularly in
| applications like rocketry, where your structural strength
| tolerance are very tight.
| metal_am wrote:
| I know for certain that defects in the powder layer can be
| fixed in binder jet by redoing the recoater. There has been
| talk in the research world about being able to fix errors
| in L-PBF but I'm not sure they've gone past the research
| stage. The big point is that you can know a part might be
| out of whatever your acceptance criteria might be.
| serf wrote:
| >It's just that it's very easy for deviations from what the
| sensors see to occur.
|
| right, but this is a problem in any modern precision
| machining, and it has been (mostly) conquered to a degree
| that we can produce _very_ precise things in an almost
| entirely automated fashion.
|
| >If material is missing somewhere, you could have the
| machine go back and add it
|
| laser sintering is easier to audit than a normal fdm style
| print in a lot of ways if you care to take the time to do
| it. The process can be paused fairly easy with the right
| machine and right environment, the product can be weighed
| mid-process, it can have all sorts of vision and laser
| metrology done to the product midway through production;
| whatever -- and the mid print failure rate is
| astronomically lower than extrusion based methods.
|
| it doesn't seem that unbelievable to me.
| metal_am wrote:
| Peregrine from Oak Ridge National Lab does exactly this. Lots
| of other research papers about it too.
| Ruthalas wrote:
| You are correct, and with the current metal AM techniques
| (DED, SLM), you can also take thermal imaging of the melt
| pool throughout. From this you can a pretty accurate picture
| of the weld quality across the whole volume.
|
| I'm not sure that's sufficient to eschew any other non
| destructive testing, but it is great information.
| mywittyname wrote:
| > Maybe even photograph each layer as you go?
|
| Differential cooling is an issue, and is one that isn't
| apparent until the layers have already been printed.
|
| If their process actually works, whatever they are doing
| isn't trivial.
| dim13 wrote:
| Very Indian approach. Print a report, and call it a day. :D
| LargeTomato wrote:
| They may be skipping small portions of the post-print qual. Or
| more likely, they're just more confident that the pieces being
| created are of a certain level of quality. It's a hype-y
| statement but they're probably trying to highlight that they're
| doing some sort of software-defined quals.
| eagerpace wrote:
| This is really neat, but would like to know more about the
| engine. The image seems to show a very simple design, without
| turbo pumps that are a mainstay in any other "rocket" engine.
| russdill wrote:
| It looks like it's electric pump fed, and it doesn't look like
| those pumps are part of the engine. Is it just a combustion
| chamber then?
| shrubble wrote:
| I wish them well, but the rocket went less than 9km to apogee and
| 8km over the ground. It has to continue improving...
| 1024core wrote:
| Wright Brothers first airplane flew only 100m or so.
| nvy wrote:
| The "Wright Brothers" moment for rocketry happened 60 years
| ago.
| gridspy wrote:
| The first useful rockets were during the second world war,
| used for artillery into London. So over 80 years ago.
| https://en.wikipedia.org/wiki/V-2_rocket
| hermitcrab wrote:
| Depends what you mean by 'useful'. They were a
| technological marvel, but an incredibly inefficient way
| to deliver approx a ton of high explosive. But I guess we
| should be thankful that Hitler wasted so much of
| Germany's increasingly scarce resources on 'Wunderwaffe'
| like rockets. The Allies developed technology that was
| less showy, but much more useful (computers, cavity
| magnetron, proximity fuze, atom bomb etc).
| nvy wrote:
| Yeah I was referring to Sputnik, as the V2 wasn't
| orbital.
| surfingdino wrote:
| Nice pre-flight photo of the engine. Could we also have a look at
| the engine post-flight?
| HarHarVeryFunny wrote:
| Relativity Space are also 3-D printing not just rocket engines,
| but entire rockets, and have had a successful first flight.
|
| https://www.youtube.com/watch?v=kz165f1g8-E
| CarVac wrote:
| They backed away from printing entire rockets because, well,
| it's a foolish way to fabricate large tanks.
| HarHarVeryFunny wrote:
| Thanks - I wasn't aware of that, but it does make sense.
|
| They are sticking with 3-D printing of the engines though,
| and have been testing their next-gen Aeon R engine.
|
| https://www.youtube.com/watch?v=QjKJMcOQYBQ
| anonymousd3vil wrote:
| Kudo's to the team! This is a great success.
| surfingdino wrote:
| I hope they all get to ride on it like true engineers would.
| constantcrying wrote:
| >Constructing a rocket engine using conventional approaches can
| take months, followed by extensive qualification testing to
| ensure it meets the required specifications. Using a metal 3D
| printer from German company EOS, Agnikul produced its engine in
| roughly three days. Agnikul printed the engine out of inconel, a
| high-performance alloy of nickel and chromium that can withstand
| high temperatures and mechanical loads. The machine also
| automatically outputs a report that details any deviations during
| printing, removing the need for postfabrication qualification.
|
| What amateurs are at work here? This plainly is not true and if
| you believe this can work you can not be trusted to be anywhere
| near an engineering project.
|
| Besides, the question I have is _why_ 3D printing? There are
| innumerable ways to manufacture a rocket, why did they choose 3D
| printing? If it is because they think you don 't need
| qualification and testing for the produced hardware they should
| not be allowed to launch anything they make.
| sa1 wrote:
| What part is not true?
|
| https://www.youtube.com/watch?v=kz165f1g8-E
|
| I'm sure that there are lots of problems with this approach,
| but it is not as obvious as your comment makes it out to be.
| constantcrying wrote:
| The part which is not true is: "removing the need for
| postfabrication qualification"
| sa1 wrote:
| Makes sense, thank you
| tonyarkles wrote:
| > Besides, the question I have is why 3D printing?
|
| My understanding is that there's interesting things in the
| aerospace industry that are very difficult or sometimes
| impossible to machine from a single part in a conventional
| subtractive machining process. GE is doing it as well for the
| LEAP engines: https://3dprintingindustry.com/news/ge-aerospace-
| to-scale-th...
|
| As an easy example, imagine a single-piece rocket nozzle with
| internal channels for delivering fuel and oxidizer. Pretty much
| impossible to machine and not that big of a deal* to do with
| additive manufacturing.
|
| * Your mileage may vary, talk to your doctor for details. :)
| OutOfHere wrote:
| "When you don't have any real criticism, just make stuff up!
| Keep people down at all costs."
|
| P.S. Nick checks out.
| constantcrying wrote:
| How is gross negligence on QA not a "real criticism"?
| OutOfHere wrote:
| You hardly enough know anything about the project to make
| an assumption about the absence of QA. If you were an
| employee there, and you had specific concerns, that would
| be worth something. You made it up because you had no real
| point.
| constantcrying wrote:
| >You hardly enough know anything about the project to
| make an assumption about the absence of QA.
|
| I take their claims at face value. Either they are for
| some weird reason lying about not doing QA or they are
| extremely negligent in their manufacturing. Granted, I
| can not exclude the first option, but to be honest that
| might make the company look even worse.
| OutOfHere wrote:
| They're not shipping people into space with this tech
| yet. As such, even if QA were missing, which we don't
| really know much about, the need for QA is way less than
| you make it out to be. It's not a big deal if a cargo
| rocket blows up, and so far it hasn't even blown up.
| Together, this is why your line of comments is
| unqualified.
| constantcrying wrote:
| I sincerely hope you are never involved in any aerospace
| projects.
| OutOfHere wrote:
| Like I said originally, when you run out of arguments,
| not that you ever had one really, you resort to forms of
| attacks that are not substantiated by any logic. You
| don't know me or what I would do if I were or were not
| involved in aerospace. Maybe you want to go taunt Elon
| Musk for how many rockets his company has blown up.
| constantcrying wrote:
| If you don't understand that rocket hardware needs QA,
| please stop talking about the subject. It is like a
| software engineer who believes that software should be
| shipped without any testing.
|
| >You don't know me or what I would do if I were or were
| not involved in aerospace
|
| True. I still hope that you are never involved in any
| aerospace or remotely safety critical project.
| OutOfHere wrote:
| I hope you are not involved in anything at all, as you
| look to be a fairly toxic person to be around who will
| put others down at all costs.
|
| Also, like I said, you have no idea of the emphasis I
| place on safety when the situation and funding merit it.
| gridspy wrote:
| > Maybe you want to go taunt Elon Musk for how many
| rockets his company has blown up.
|
| We know that Elon's SpaceX has many machines inspecting
| 3D printed (and other) parts, as per the SpaceX factory
| tours on YouTube.
| https://youtu.be/xahiWQQKw7Y?si=UGZ1u9xTil5iYoBi&t=71
|
| Also, SpaceX blows up very few (none?) operational
| rockets. They only tend to blow up in novel ways while
| testing new technology.
|
| Bear in mind that the SpaceX Raptor is a cutting edge
| engine - full flow staged combustion is hard.
| stainablesteel wrote:
| relativity space does this as well, they have youtube videos on
| what they do
| constantcrying wrote:
| They don't do qualification of their hardware? Why would you
| put that on YouTube?
| stainablesteel wrote:
| i dont know about that part, but they 3d print
|
| i don't honestly believe there's anyone building a rocket
| like this that isn't concerned about the rockets success
| constantcrying wrote:
| Why are they saying they don't need QA then?
|
| Sure, you can use whatever appropriate manufacturing
| processes you want. But none of them can replace QA.
| krisoft wrote:
| > Besides, the question I have is why 3D printing?
|
| Rocket nozzles are heat limited. You could get more trust out
| of them only if the nozzle would not melt. So you do a lot of
| tricks to cool it. One of those many tricks is that you
| circulate your rocket fuel as a coolant in the wall of the
| nozzle. This requires an intricate web of many tiny pipes which
| form the wall of the nozzle.
|
| Typically these are constructed by hand by brazing together
| many many pipes. That takes forever. In contrast additive
| methods seem to perform well in this application.
|
| This is standard stuff nowadays. Everyone seems to be doing it.
| I'm not sure what is your objection. If you don't believe me
| listen to Tony Bruno:
| https://youtu.be/Bh7Xf3Ox7K8?si=YVDIDq1bvKeCuvY9&t=1509
|
| > This plainly is not true
|
| Which particular part are you objecting to?
| jfyi wrote:
| My guess is failing to read between the lines and taking
| marketing too seriously.
|
| "Removing the need for postfabrication qualification" doesn't
| mean "perfectly detects errors" it means "detects errors
| within our business specs and we expect it to be profitable
| within that margin".
| wongarsu wrote:
| In a typical rocket the payload is the most expensive
| thing, followed by the engines, and then the rest of the
| rocket and the fuel. Shaving costs off the engines is well
| worth it, but not if it sacrifices reliability.
|
| Maybe they have a model in mind where it works. If you use
| dozens of engines like SpaceX's Starship you can tolerate
| more engine issues. Of maybe they want to launch really
| cheap payloads on inexpensive rockets. But in the
| parameters of traditional rocket design, QA on your engines
| is one of the last things you want to save money on.
| wongarsu wrote:
| 3d printing rocket engines makes a lot of sense. The engines of
| Rocket Lab's Electron rocket are 3d printed, Aerojet
| Rocketdyne's AR1 engines have 3d printed fuel injectors,
| SpaceX's SuperDraco thrusters (the ones in the Dragon 2
| capsules) are 3d printed. Complex geometries with lots of
| liquid channels make rocket engines difficult to machine, so
| overcoming the issues with 3d printing heat-resistant parts is
| well worth it.
|
| But skipping qualification testing is indeed a weird reason. I
| doubt you can skip test fires.
| elteto wrote:
| SpaceX has been printing the Draco and Super Draco engines for
| the Dragon capsule for many years. It's a proven technology at
| this point.
|
| With 3D printing you can create geometries that are simply not
| possible with any other manufacturing processes.
|
| The issue is not 3D printing. The issue is deluding yourself by
| thinking that somehow 3D printing is magical and you get to
| skip qual. You don't.
| bagels wrote:
| Integrating all the plumbing in to the structure is a lot
| easier to achieve with 3d printing.
| bufferoverflow wrote:
| At the very least, 3D printing allows nearly full automation
| without having to create expensive custom production lines.
| AustinDev wrote:
| Can't wait to 3D Print a bootleg PATRIOT system.
| instagraham wrote:
| I take it you've seen the DIY 3D printed SAM some random Hong
| Kong dude made?
|
| https://www.youtube.com/watch?v=UvcDwSmmxWs
| fullspectrumdev wrote:
| I really would love to have the time and energy to replicate
| that. That guys work is pretty nuts
| instagraham wrote:
| based on his other videos, either he's actually a Chinese
| missile scientist or you can pretty much make an entire
| rocket fleet in your farm in modern China
| mlindner wrote:
| Patriots use solid fuel. Additionally nothing on a Patriot
| missile used 3D printing. There is no benefit for 3D printing.
| 29athrowaway wrote:
| I hope this doesn't lead to an exponential increase in space
| debris.
| 1024core wrote:
| Elon can litter the sky with 100s of cheap satellites... but
| heaven forbid that an Indian startup build 1 rocket, right?
|
| Oh bigots of HN, you never fail to disappoint me.
| 29athrowaway wrote:
| If SpaceX could produce a rocket every 72 hours it would be a
| concern too.
|
| Also, best of luck in your quest of fighting imaginary
| villians.
|
| By conflating unrelated things and jumping to conclusions
| such as that you are not acting as a good ambassador for your
| country.
| nordsieck wrote:
| > If SpaceX could produce a rocket every 72 hours it would
| be a concern too.
|
| Just FYI, SpaceX is trying to launch a Falcon 9 about every
| 48 hours this year.
|
| So far they seem pretty responsible about things, though.
| MobiusHorizons wrote:
| I don't hear anyone disparaging the ability of Indian
| companies to build great rockets. ISRO has done some really
| great work, and deserves lots of credit. But this startup
| seems to be bragging about making some pretty basic mistakes,
| like claiming not to need QA without having actually done
| anything to solve that problem (they didn't build the 3d
| printer). So they seem to be doing the same kind of non-
| serious stuff we see from other vc backed startups all over
| the world which deserves skepticism.
| agent13 wrote:
| Wow. Talk about getting triggered.
| 1024core wrote:
| Hang out in HN long enough, and you'll see what I'm talking
| about.
| nedpat wrote:
| Test
| panick21_ wrote:
| 3D printing is the conventional way of designing rocket engines
| today. Literally every new rocket startup does it a lot. Its more
| unconventional how much isn't 3D printed on the SpaceX Raptor.
| imtringued wrote:
| Now do it again, but this time build a fully automated rocket
| factory on the moon.
| paulsutter wrote:
| If you take a look at a real rocket engine you will see hundreds
| of parts that cannot be printed
|
| Raptor 1, 2, and 3:
|
| https://www.nextbigfuture.com/2023/07/spacex-further-improve...
| mlindner wrote:
| For very simple pressure fed engines (which this appears to be)
| it's actually cheapest to additively manufacture (3D print)
| engines as you can integrate the cooling channels. On engines
| like Raptor you have pumps, which notably need to move so while
| you still use 3D printing (Raptor uses a ton) you can't print
| it in a single piece.
|
| 3D printing is already an industry standard and nothing this
| company did with relation to its engine manufacturing is
| anything special. They also appear to have lied that no post-
| manufacturing qualification is required.
| Narhem wrote:
| Not surprised hellers have been doing it for centuries for
| pennies
| mlindner wrote:
| This company has been pushing a lot of press about this but it's
| really not anything special. The industry has been printing
| engines for many years and the time to print is dependent on the
| size (and to some extent the mass) of the engine and the speed of
| the printer. Take this with a grain of salt.
| hi-v-rocknroll wrote:
| It sounds like they're not doing QC/QA, which would be unwise and
| maybe isn't necessarily true.
|
| While 3D printing allows printing shapes that cannot be forged or
| cast, testing is always needed as part of the manufacturing
| process feedback loop. X-ray and dye penetration nondestructive
| testing check for abnormalities on accessible services, but
| destructive testing is needed sawing samples into slices to also
| check them for hidden defects.
| newswasboring wrote:
| I've seen less skepticism on cryptocoin threads on HN. The
| absolute racism in this thread is disgusting.
| 93po wrote:
| i wish there was more than a single photo, and maybe some cross
| sections or something. didn't see any with a quick google
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