Indian startup 3D prints rocket engine in 72 hours

The problem is that warning sign comes at around 10ms or less before the actual disaster

But _only_ testing in prod is bad.

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.

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.

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.

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.

The most common form for metal precision production is powder bed fusion

You deposit a whole layer of powder and a laser melts the desired parts

i don't honestly believe there's anyone building a rocket like this that isn't concerned about the rockets success

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.

Reminds me of that failing nuclear startup that tried “fake it until you make it” with the US government.

You have to be way more specific when you want to actually be insightful about the topic.

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.

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.

> 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.

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.

WDon't believe everything you read in headlines written by people with no understanding of the space industry. If you want to read about the industry, read about it on industry specific sites (like spacenews.com) or from industry specific reporters (Eric Berger or Stephen Clark at ArsTechnica). Davenport at Washington Post is good too.