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Comment by kretaceous | Hacker News Reader

Sorry I'm out of the loop/don't really understand what this is. Why would it blow up?

Starship is a massive two stage rocket/ship. Most powerful rocket in history. This is the first attempt at launching the full stack. To reach orbit, a rocket needs to be highly optimised, with little room for error. If errors occur, it could explode. Errors are most likely to happen the first time you try something.

I am aware it's not strictly aiming to reach orbit

In rocketry, the failure of any one part often results in total system collapse. This rocket has far more such parts than most. And it is a very big system. Any collapse will be spectacular. But if all goes well, that too will be a sight to see. Rocketry is about explosions: either you direct the explosion downwards as thrust or it overtakes you and goes omnidirectional. Either way, an explosion will happen.

Why would you expect your code to compile and run correctly on the first try? Same energy.

They can test / simulate as much as they want on the ground but the first full launch is bound to reveal issues.

Best case those issues just stop it from reaching the desired level of performance, more realistically they mean it goes boom at some point.

It's a rocket so there is always a non-zero risk of explosion. This one is also a new, not-yet-launched rocket, making it extra non-zero chance of explosion.

A rocket is basically a controlled explosion, and when you stop controlling it, explosion is likely.

Ah yes, just like fossil-fueled cars, but on a different scale :)

No. This is external combusion of cryogenic fuels at low pressures. There is no crossover beyond the fact that both involve rapid oxidation.

A gas engine reaches about 1200 psi, a diesel reaches about 2500 psi. Raptor’s combustion chamber sits at 4500 psi.

Which is completely nuts, even for a rocket engine. The F1 powering the saturn V only ran at 1000 psi.

On the other hand, ANFO, a common low pressure explosive, has a detonation pressure of ~100,000 psi

Its and apples and oranges comparison of combustion chambers. For purposes of combustion, the relavant pressure is the exaust of the rocket engine where combusion is complete. The burning gas within an ic engine is, at the point of combusion, at a very higher pressure. The ic equivalent of a rocket combusion chamber would be the blast wave starting at the spark, which then moves through the fuel. This difference become more important when discussing the new tech of pulse detonation rocket engines.

What is a fossil-engine if not a engine that does a bunch of small, controlled explosions very quickly? Sounds like they're identical to me ;)

This type of rocket doesnt use explosions. It burns fuel steadily. A car detonates fuel in packets. It is a different type of combustion.

I'm not aware of a single type of orbital rocket reaching orbit successfully on first attempt. Not all of them blew up, but many did.

SLS? It not only made orbit but also got it's payload around the moon. While it used many previously proven technologies (and it even previously flown engines), those were either modified or combined in previously untried ways, enough that I'd call it a new vehicle for the purposes of a flight test.

Speaking of previously proven technologies... the Space Shuttle made it to orbit on it's first launch attempt as well... with crew.

By that definition there are lots of rockets who flew successfully at first. Falcon 9 for example.

Falcon 9? SLS? STS?

Falcon 9 did.

Zenit-3SL, Angara, Saturn family.

Juno did just fine.

I think it is no company has reached orbit on first attempt. But they have been successful on later rockets. This includes SpaceX which was blowing up rockets phase with Falcon 1 but were successful with Falcon 9.

Now I'm inspired to try to fill out this list...

Pegasus (company's first try overall), Antares, all of the Minotaurs, Atlas 3 and 5 might count as new... Epsilon, H-2 (new?), Vega, Ariane 1, 3 & 4... And the Ariane 1 is both totally new on a systems level and an institution's first attempt at building one. Long March 5, 6 & 7.

Of the investor-backed launch startups, I think it's either no company got it first try... or Orbital Sciences counts as making it first try with Pegasus. Not sure if they count as an investor backed startup.

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