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Urwumpe

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N_Molson

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Very interesting, the fires start with the beginning of the TVC test program. Could be pure coincidence, though.

They said that what actually caught fire was the adhesive between the extra insulations layers. So it would make sense that moving the nozzles opened tiny gaps between the insulation blankets that released the "adhesive gases" (because gases emanating from materials are what actually feed fires). Yeah I'd expect the heat to be pretty insane between 4 massive LOX/LH2 engines, especially after several minutes of static firing. At such temperatures pretty much everything can be set on fire, because everything begins to melt and release gases (even concrete or steel), that's why the nozzles themselves are cooled, and one of the reasons for the "Niagara falls" around the rocket : water absorbs some of the acoustic loads but also ensures the test rig structure stays cool. As long as you keep fresh water in. Which is probably a wise precaution.

If it had to be some ground-only crazy construct designed to burn hydrogen for hours, coolant loops should probably be added on the aft bulkhead.
 

Thunder Chicken

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Very interesting, the fires start with the beginning of the TVC test program. Could be pure coincidence, though.

But the fires also seemed to start at the point of the highest heat load in the center of the four engines.
The engine thrust entrains a lot of air which cools the outer surfaces, but between the engines you get a relatively stagnant and isolated region of gas with maximum radiation heating, very little convection, and low oxygen. When the TVC started that probably stirred some oxygenated air into the center region. Something like the backdraft effect in a burning building - a room may be fully consumed and very hot, but not burning very strongly because of the lack of oxygen. But open a door and FOOF!

 

Urwumpe

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The engine thrust entrains a lot of air which cools the outer surfaces, but between the engines you get a relatively stagnant and isolated region of gas with maximum radiation heating, very little convection, and low oxygen. When the TVC started that probably stirred some oxygenated air into the center region. Something like the backdraft effect in a burning building - a room may be fully consumed and very hot, but not burning very strongly because of the lack of oxygen. But open a door and FOOF!


Thats actually a great hypothesis there, it makes perfectly sense. Especially if you combine it with the pyrolysis products of the adhersive. Maybe the TVC allowed oxygen to enter the gaps in the insulation and started the fire there, maybe even inside the insulation.
 

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Ah, the long-awaited testing is finally complete! Will Orion open its wings to the Moon in 2022? Will Americans return to the lunar surface in the 60th anniversary of Apollo 8 in 2028? Damn, I tend not to focus on these schedules since 2020.
 

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Nasa has assembled the first of its powerful Space Launch System (SLS) rockets, which will carry humans to the Moon this decade.
On Friday, engineers at Florida's Kennedy Space Center finished lowering the 65m (212ft) -tall core stage in-between two smaller booster rockets.
It's the first time all three key elements of the rocket have been together in their launch configuration.

 

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NASAspaceflight reporting that SLS is targeting a launch date of November 4th.

Personally, I think November 4th, 2022 is more likely. :confused:
Me too, as I exclaimed to the long-awaited Green Run test in April 2021:
Ah, the long-awaited testing is finally complete! Will Orion open its wings to the Moon in 2022? Will Americans return to the lunar surface in the 60th anniversary of Apollo 8 in 2028? Damn, I tend not to focus on these schedules since 2020.
I'm still uncertain with the Artemis program, and I believe that the current schedule of Artemis missions are likely to be disrupted by some intercontinental conflicts. I recently dreamt that the remains of Apollo on the Moon are mostly filled with the lunar dust with no man to recover them. This made me sad that we will be trapped within low Earth orbit for seventy years with no BLEO exploration since 1972.
 

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Seems likely we'll see a maiden flight in 2022. Not sure how many launches there will be after that, but still should be a cool sight.

and I believe that the current schedule of Artemis missions are likely to be disrupted by some intercontinental conflicts.

Well, if a major intercontinental conflict starts, last thing we'll have to worry about is Artemis... ☢️💀💀 No, I think that what will decide the fate of Artemis is what happens inside and above the United States. If the Space-thing magic rocket hold all its promises (again I don't like it and I'm still very sceptical about it, but hey "wait and see"), there will be little use (and/or political support) for something like Artemis. Then IMHO the best thing that could happen is Russia or China add some competitive space program pressure (China seems on the tracks, Russia not yet). USA did great things under pressure during the 1960's and 1970's, it could happen again in nowaday's more "open" economic environment.
 

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That is cruel...

When all former components of the STS are going to the Moon except for the shuttle orbiter itself.
Press F to pay respect

I'd say this is the best thing the Shuttle program could hope, there's no cruelty there. Parts of those great machines served well in the past and will now serve an even greater purpose. Personally I find a bit weird to give human feelings to machines. Well I could change my mind the day I'll meet a convincing android but rocket parts don't have anything like a free will...
 

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It's something to see Discovery at Udvar-Hazy and Atlantis down at KSC as museum pieces, when I spent my formative years watching them actually fly. People see them now as relics of a bygone era, just as I have seen the relics of Saturn/Apollo during my life.

I am wondering if we'll ever see SLS do anything of such import that their hardware will be venerated in museums 20 years hence. I doubt.
 

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I'd say this is the best thing the Shuttle program could hope, there's no cruelty there. Parts of those great machines served well in the past and will now serve an even greater purpose. Personally I find a bit weird to give human feelings to machines. Well I could change my mind the day I'll meet a convincing android but rocket parts don't have anything like a free will...
There had been several attempts to use the "[p]arts of those great machines" to "serve an even greater purpose" before SLS, but none of them served their purpose. Wikipedia has a long list of those attempts, so I don't wanna spoil this comment with the list. However, the craziest of those attempts are Ares I and Boeing SRB-X, whose nasty g-forces make them unreliable for both crew and cargo.
 
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