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Starship Flight 7

spacex.com

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Re: Starship Flight 7

#761

Post by __m »

jiggawatts wrote: post #706
hooli_gan wrote: post #644

Earlier quoted context omitted.

If you think these are mere delays, then I have a bridge to sell to you

In about two years, when these things will be launching hundreds of starlink satellites like clockwork, you’ll just move the goalposts and find something else to criticise. I’m saying this with confidence because it’s the established history of SpaceX critics. Everything from reusable rockets, space internet, full-flow staged combustion, etc.. has had its naysayers that all shut up and found something new to critique…

I’m still waiting for the concert hall with glass ceiling in starship and the restaurants and zero-g games that serve 100 people, shouldn’t they have landed on mars by now? I think it will be more than 2 years before I start moving goalposts

Re: Starship Flight 7

#762

Post by bamboozled »

The5thElephant wrote: post #700
computerex wrote: post #556

Earlier quoted context omitted.

Guy is a serial liar and you are making excuses on his behalf.

He is a serial liar, but we can also actually see the engineering progress which is remarkable regardless of his overinflated timelines. His lying doesn't change the incredible work by those engineers and other employees of SpaceX.

What does he have to do with the incredible work though ? Shit posting his way to mars ?

Re: Starship Flight 7

#763

Post by ricardobeat »

me_me_me wrote: post #759
ricardobeat wrote: post #731

Earlier quoted context omitted.

No, that’s about “SpaceX learning from NASA’s past mistakes”. You also don’t seem to get the point that they were 2-year old programs when Curiosity started, so I’ll just leave it here.

Yeah leave it here. You are probably tired after moving the goalposts so many times.

Please don’t play these games on HN. A few of these threads will get your account flagged.

It was a single comment, how can the goalposts have moved “so many times”. You made no effort to engage on a reasonable discussion, and made a smart-ass comeback with something I did not say instead, it’s simply not an interesting conversation to be had.

Re: Starship Flight 7

#764

Post by coldtea »

pmontra wrote: post #409
coldtea wrote: post #358

Earlier quoted context omitted.

[flagged]

Test flights. My tests keep failing until I fix all of my code, then we deploy to production. If code fails in production than that's a problem. We could say that rockets are not code. A test run of a Spaceship surely cost much more than a test run of any software on my laptop but tests are still tests. They are very likely to fail and there are things to learn from their failures.

>Test flights. My tests keep failing until I fix all of my code, then we deploy to production.

Do your tests require tens of millions, and can have potential casualties?

Re: Starship Flight 7

#765

Post by littlestymaar »

ben_w wrote: post #710
littlestymaar wrote: post #694

Earlier quoted context omitted.

It's not liquid at the point of ignition, that's the thing: if you mixed liquid oxygen and fuel nothing would happen expect the fuel would freeze. For a fire to take place the temperature must reach the fire point temperature, and if you manage to get your fire below this temperature then the fire stops. I don't know how low this temperature can be when the oxidizer is pure oxygen and maybe it's so low water wouldn't…

I believe LOX is injected into the engine as a liquid, it gets atomised rather than boiled? And you can have fires where both fuel and oxidiser are solid: thermite reactions. "Fire point" seems to be more of a factor for conventional fire concerns, albeit I'm judging a phrase I've not heard before by a stub-sized Wikipedia page: https://en.wikipedia.org/wiki/Fire_point

It's not about the state itself, but about temperature. For things to burn you need to have three elements:

- a fuel

- an oxidizer

- enough heat

It's the fire triangle.

Re: Starship Flight 7

#766

Post by MrSkelter »

Saturn 5 was landing on the moon for the second time on its seventh flight. We have access to everything that program learned and taught for free. It’s all 60 year old tech. People shouldn’t forget how shockingly tardy and poorly designed Starship is by comparison.

7 flights in and it’s still exploding in a system that will require more than 10 launches for a single lunar flight.

I am sure Musk’s groupies will assemble but the facts don’t care about your fandom.

Re: Starship Flight 7

#767

Post by ben_w »

littlestymaar wrote: post #765
ben_w wrote: post #710

Earlier quoted context omitted.

I believe LOX is injected into the engine as a liquid, it gets atomised rather than boiled? And you can have fires where both fuel and oxidiser are solid: thermite reactions. "Fire point" seems to be more of a factor for conventional fire concerns, albeit I'm judging a phrase I've not heard before by a stub-sized Wikipedia page: https://en.wikipedia.org/wiki/Fire_point

It's not about the state itself, but about temperature. For things to burn you need to have three elements: - a fuel - an oxidizer - enough heat It's the fire triangle.

> but about temperature

Which is why I said water would raise the temperature because the oxygen is liquid oxygen — i.e. very cold.

I mentioned solid phase because you were saying "if you mixed liquid oxygen and fuel nothing would happen". There are also videos of people starting fires by pouring LOX onto things.

The fuel and oxidiser in a rocket are often pumped around the outside of the engine bell before reaching the injectors, in order to keep the engine bell itself from melting due to the heat of combustion. I'm not sure exactly what temperature the fuel and oxidiser are at when they hit the injector, but I've seen ground tests where there's frost on the outer wall while the engine is running.

Also, one of the (rare) Falcon rocket failures was due to ice (IIRC oxygen ice) building up around the plumbing during flight: https://www.adastraspace.com/p/spacex-falcon-9-grounded

Re: Starship Flight 7

#768

Post by littlestymaar »

ben_w wrote: post #767
littlestymaar wrote: post #765

Earlier quoted context omitted.

It's not about the state itself, but about temperature. For things to burn you need to have three elements: - a fuel - an oxidizer - enough heat It's the fire triangle.

> but about temperature Which is why I said water would raise the temperature because the oxygen is liquid oxygen — i.e. very cold. I mentioned solid phase because you were saying "if you mixed liquid oxygen and fuel nothing would happen". There are also videos of people starting fires by pouring LOX onto things. The fuel and oxidiser in a rocket are often pumped around the outside of the engine bell before reaching…

> Which is why I said water would raise the temperature because the oxygen is liquid oxygen — i.e. very cold.

Water is hotter than liquid oxygen indeed, but it's still much colder than a fire with fuel and oxygen.

> I mentioned solid phase because you were saying "if you mixed liquid oxygen and fuel nothing would happen". There are also videos of people starting fires by pouring LOX onto things.

Do you have an example of such a video? Because in all liquid oxygen I could find on YouTube right now they are always setting the thing on fire (which gives it the initial heat). As I said, it's possible that some mixture of pure oxygen and some fuel have a fire point that is below 0°C, in which case water wouldn't work. But then you could use another (non-flamable) fluid that would be at a temperature below that fire point.

> The fuel and oxidiser in a rocket are often pumped around the outside of the engine bell before reaching the injectors, in order to keep the engine bell itself from melting due to the heat of combustion. I'm not sure exactly what temperature the fuel and oxidiser are at when they hit the injector

The temperature when they hit the injector is irrelevant, what matters is the temperature at the fire boundary.

Imagine a gas stove: the gas reaches the injector around room temperature, but as soon as it reaches the flame of the previous gas (or a match, or a spark from the piezo igniter), it starts burning. But if you pour a glass of water on it (or if you just turn the gas on without igniting it), it will stop burning, and the gas is now just going to spread into the room without burning (don't do this at home, you'd blow up your house)

Re: Starship Flight 7

#769

Post by jiggawatts »

__m wrote: post #761
jiggawatts wrote: post #706

Earlier quoted context omitted.

In about two years, when these things will be launching hundreds of starlink satellites like clockwork, you’ll just move the goalposts and find something else to criticise. I’m saying this with confidence because it’s the established history of SpaceX critics. Everything from reusable rockets, space internet, full-flow staged combustion, etc.. has had its naysayers that all shut up and found something new to critique…

I’m still waiting for the concert hall with glass ceiling in starship and the restaurants and zero-g games that serve 100 people, shouldn’t they have landed on mars by now? I think it will be more than 2 years before I start moving goalposts

Do you get equally upset when a concept car isn’t something you can buy at the local dealer the very next year?

Why are you so upset by the aspirations of others?

Re: Starship Flight 7

#770

Post by nomel »

drillsteps5 wrote: post #754
nomel wrote: post #699

Earlier quoted context omitted.

> spaceflight is not the place where it is appropriate. But, a video stream meant for the public consumption is. SI are standardized for the context of calculations , not necessarily for human consumption, which happens to be why nobody gives the weather in degrees kelvin.

Their main target audience is still space geeks. Parts of broadcast will be shown in daily news bits on cnn and reuters, who will still translate the height to football fields, velocity to car speed, etc. Geeks will watch and re-watch it multiple times and fight over crazy theories online and it really helps if you can use normal units of measure. Btw the rest of the world measure temperature in Celsius which is deri…

> Btw the rest of the world measure temperature in Celsius which is derived from Kelvin (by adding or subtracting the value of absolute zero in Celsius).

Yet, it's not SI, because it's for humans. The same could be said for using km/h. The rest of the world measured speed in km/h which is derived from m/s (multiplying by a constant).

They're presenting units that people are most familiar with, that most people see and experience, modulate with their foot, every day of their lives. The presentation is for humans, not calculators. The best way to make people interested is to make things relatable, and let the interested people do the trivial math they're so familiar with. It's good PR, and an example of why engineers shouldn't be involved with PR.

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