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Indian startup 3D prints rocket engine in 72 hours

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Re: Indian startup 3D prints rocket engine in 72 hours

#161

Post by chfalck »

throwitaway222 wrote: post #152
sandworm101 wrote: post #142

Earlier quoted context omitted.

>> 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…

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.

It’s a bit of chicken and egg to know if you built it robust enough without meticulous testing of your robustness

Re: Indian startup 3D prints rocket engine in 72 hours

#162

Post by ruined »

jes5199 wrote: post #156
sandworm101 wrote: post #142

Earlier quoted context omitted.

>> 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…

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

this works for munitions, but not for payloads that anyone cares about.

Re: Indian startup 3D prints rocket engine in 72 hours

#163

Post by lesuorac »

lukan wrote: post #144
rvnx wrote: post #73

Earlier quoted context omitted.

If it would be a Tesla, just enough time for the auto-pilot to disengage and claim it was the fault of the user.

Is there data, that indicates Tesla did this, or something like this?

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...

Re: Indian startup 3D prints rocket engine in 72 hours

#164

Post by nordsieck »

alephnerd wrote: post #14
nordsieck wrote: post #12

Earlier quoted context omitted.

> 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. Whic…

> 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.

> 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.

Re: Indian startup 3D prints rocket engine in 72 hours

#165

Post by nordsieck »

29athrowaway wrote: post #119
1024core wrote: post #104

Earlier quoted context omitted.

[dead]

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.

> 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.

Re: Indian startup 3D prints rocket engine in 72 hours

#166

Post by fullspectrumdev »

jes5199 wrote: post #156
sandworm101 wrote: post #142

Earlier quoted context omitted.

>> 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…

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

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.

Re: Indian startup 3D prints rocket engine in 72 hours

#167

Post by fullspectrumdev »

instagraham wrote: post #143
AustinDev wrote: post #74

Can't wait to 3D Print a bootleg PATRIOT system.

I take it you've seen the DIY 3D printed SAM some random Hong Kong dude made? https://www.youtube.com/watch?v=UvcDwSmmxWs

I really would love to have the time and energy to replicate that. That guys work is pretty nuts

Re: Indian startup 3D prints rocket engine in 72 hours

#168

Post by toss1 »

ETH_start wrote: post #154
toss1 wrote: post #121

Earlier quoted context omitted.

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.)

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.

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.

Re: Indian startup 3D prints rocket engine in 72 hours

#169

Post by switchbak »

ruined wrote: post #162
jes5199 wrote: post #156

Earlier quoted context omitted.

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

this works for munitions, but not for payloads that anyone cares about.

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.

Re: Indian startup 3D prints rocket engine in 72 hours

#170

Post by sjsdaiuasgdia »

ETH_start wrote: post #153
abduhl wrote: post #114

Earlier quoted context omitted.

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 fai…

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.

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.

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