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8 minutes ago, sevenperforce said:

My best guess is that there’s another propellant flow issue. With the 1-2 relight they do, it almost looks like the torque from the first engine startup might have introduced unexpected slosh in the lines to its companion.

Fluid management is hard. 

Could they make a jig on the ground that like rotates the whole ship while the engines are trying to be lit (at least turbopumps on) ? Like, just to test the effects etc...

Still wouldn't simulate the free-fall though...

Edited by YNM
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2 minutes ago, YNM said:

Could they make a jig on the ground that like rotates the whole ship while the engines are trying to be lit (at least turbopumps on) ? Like, just to test the effects etc...

That seems unnecessary in a hardware-rich flight test program. They're building tons of prototypes, why not just throw a few at the problem and test what happens in a realistic dynamic situation?

Edited by RealKerbal3x
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2 minutes ago, RealKerbal3x said:

That seems unnecessary in a hardware-rich flight test program. They're building tons of prototypes, why not just throw a few at the problem and test what happens in a realistic dynamic situation?

Given the amount of explosions that could be involved I expect a call from the neighboring AFAC...

Edited by YNM
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I’m calling it early ish. 
 

another fuel pressure issue.

 

no major hardware changes between 8 and 9 we shouldn’t really have expected anything else?  Maybe the header tanks are capable of lighting only 1 engine because it seems like that initial engine lighting causes issues for the second one 

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I'm not sure that they need to lower the payload/increase header tank size, etc. because this is a test program. There is a goal that they are working towards, and they aren't going to sacrifice performance as a first option. There is no time limit like there was with Apollo, but even so, when Saturn V had issues with F-1, they didn't say "ok, lets only take 2 to the Moon", they fixed the issues with the engines. Unless they hit a brick wall with regards to fuel system development, why would they give up so early?

Edited by Meecrob
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In manufacturing and software engineering there is an idea of refining the process as much as there is refining the product. The idea being you want to be able to test your product as fast as possible, which requires being able to build it as fast as possible. Spending time testing isolated parts before integrating them with the rest of the system can be part of the overall flow, but testing the entire thing together allows you to get much more relevant data on how it performs. This does require having multiple built "test products", but that's the idea behind the simpler construction of Starship. Increase the entire flow means you can increase how many times you test everything together, which is the real "test".

 

The fact SN9 exploded due to a failure is somewhat of a good thing, as that means you get feedback now on the problem. SpaceX seems to have the manufacturing down, as SN10 is already at the pad ready to go to continue the iterative process. Figure out what happened to SN9 fix it, and then send up SN10 with the feedback to continue to learn. 

 

This also might explain why there is no redundancy on the current systems. The goal being not so much to "save SN9", but to get data on what needs to be working in the first place.

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2 minutes ago, RCgothic said:

Sure those are legs? Maybe like like engine bell debris to me.

Sole fire they were getting from the other engine was only green, like the SN8 second engine. Maybe this was the result from that ?

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1 hour ago, tater said:

The boil off is actually pretty well understood. Natural gas and methane are commodity items, routinely stored in tanks sitting outside at ambient temp. I have a propane tank at my house (we're not on the natural gas grid), and it never vents at all that I can tell, sitting in the blazing NM sunlight in July with an ambient temp in the shade that might be >38°C.

Propane is not natural gas who is mostly methane. Propane can be stored in an pressure vessel, butane at low pressure so its used in lighters and camp stoves and lights. 
Now they could made an propane engine but ISP is lower and you need to store LOX anyway. 

Wonder that SpaceX will do with the propane from the gas well? sell it as SpaceX propane for people to use on gas grills and stoves :) it would catch an premium especially if the bottles was shaped like starship :) And Musk I want an royalty if you do so :)  But might be better idea for the NASAspaceflight group to do. 

 

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I like how the official stream showed the rocket from underneath until the last couple of seconds, then switched to a faraway camera right before the impact. As if the producer followed the feed until he saw only one Raptor was running, decided "Well, that's not nominal, this camera will be toast in three seconds" and cut away in time to have another camera capture the fireworks.

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36 minutes ago, Jaff said:

I’m calling it early ish. 
 

another fuel pressure issue.

 

no major hardware changes between 8 and 9 we shouldn’t really have expected anything else?  Maybe the header tanks are capable of lighting only 1 engine because it seems like that initial engine lighting causes issues for the second one 

I’d also say engine 1 stayed lit all the way through the flip so fuel feed to 1 engine seems to have been fixed. Still convinced that adding the second engine demand is causing the issues 

36 minutes ago, Jaff said:
36 minutes ago, Jaff said:
Edited by Jaff
Buggy forum
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23 minutes ago, magnemoe said:

Wonder that SpaceX will do with the propane from the gas well? sell it as SpaceX propane for people to use on gas grills and stoves :)

Boring Co. 'Not A Flamethrower' special resupply, obviously !

Edited by YNM
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2l5Rkrt.png

Stepping through the frames, I was parsing this frame wrong. That's a silhouette of a stopped engine, not a profile of the bell of a running engine. There is fire where there should not be fire. And no fire where there should be fire.

Edited by ExtremeSquared
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