Astronomy and Space
Re: Astronomy and Space
Apparently the destroyed ship was called SN8. How is that irreverent? I don't get it.
Re: Astronomy and Space
Has someone said it is? The next one is SN9, which seems fairly straightforward and not like a jokey naming scheme which SpaceX sometimes do. I thought last night’s test flight was awesome, that “bellyflop” manoeuvre was actually quite graceful to the point I could imagine people being inside one, once they sort out the landing.
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
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- Catbabel
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Re: Astronomy and Space
But SSN8 would be a killer name
If you bring your kids up to think for themselves, you can't complain when they do.
Re: Astronomy and Space
View of the landing - from the landing site.
https://video.twimg.com/ext_tw_video/13 ... mp4?tag=10
You can see the burn weaken at the end
https://video.twimg.com/ext_tw_video/13 ... mp4?tag=10
You can see the burn weaken at the end
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
What makes the flame go green?Gfamily wrote: ↑Thu Dec 10, 2020 2:02 pmView of the landing - from the landing site.
https://video.twimg.com/ext_tw_video/13 ... mp4?tag=10
You can see the burn weaken at the end
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
- Matatouille
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Re: Astronomy and Space
The chatter speculation has settled upon copper as the motor eats itself. As the propellent & oxidiser pressures dropped, the engines started combusting bits of itself.
Re: Astronomy and Space
Copper seems an unlikely metal to use in a rocket motorMatatouille wrote: ↑Thu Dec 10, 2020 3:09 pmThe chatter speculation has settled upon copper as the motor eats itself. As the propellent & oxidiser pressures dropped, the engines started combusting bits of itself.
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
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- Clardic Fug
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Re: Astronomy and Space
It's used in combustion chamber linersGrumble wrote: ↑Thu Dec 10, 2020 3:24 pmCopper seems an unlikely metal to use in a rocket motorMatatouille wrote: ↑Thu Dec 10, 2020 3:09 pmThe chatter speculation has settled upon copper as the motor eats itself. As the propellent & oxidiser pressures dropped, the engines started combusting bits of itself.
Re: Astronomy and Space
At 25 seconds both engines are still running but by 26 seconds the engine on the left has cut out.Gfamily wrote: ↑Thu Dec 10, 2020 2:02 pmView of the landing - from the landing site.
https://video.twimg.com/ext_tw_video/13 ... mp4?tag=10
You can see the burn weaken at the end
Re: Astronomy and Space
Huh, I’d have thought a refractory metal would be more obvious. Is it used for cooling reasons?insignificant wrote: ↑Thu Dec 10, 2020 3:48 pmIt's used in combustion chamber linersGrumble wrote: ↑Thu Dec 10, 2020 3:24 pmCopper seems an unlikely metal to use in a rocket motorMatatouille wrote: ↑Thu Dec 10, 2020 3:09 pmThe chatter speculation has settled upon copper as the motor eats itself. As the propellent & oxidiser pressures dropped, the engines started combusting bits of itself.
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
Re: Astronomy and Space
The fuel and oxidiser are commonly circulated in pipes around the combustion chamber to cool it before they are fed into the chamber, so yeah, it could be for heat transfer reasons.Grumble wrote: ↑Thu Dec 10, 2020 3:57 pmHuh, I’d have thought a refractory metal would be more obvious. Is it used for cooling reasons?
And the low fuel/oxidiser pressure would reduce the amount of cooling, and thus lead to overheating. The fuel/oxidiser ratio changing with reduced pressure could also make the combustion run hotter (running a car engine lean can lead to overheating, as another example. There the incoming fuel charge is part of the cooling of the piston and valves - running lean tends to burn valves first).
Re: Astronomy and Space
Ok, cooling the nozzle and preheating the fuel makes sense. Judging by the size of the bang there was plenty of fuel, and probably oxidiser, left so I wonder why pressure dropped.dyqik wrote: ↑Thu Dec 10, 2020 4:16 pmThe fuel and oxidiser are commonly circulated in pipes around the combustion chamber to cool it before they are fed into the chamber, so yeah, it could be for heat transfer reasons.
And the low fuel/oxidiser pressure would reduce the amount of cooling, and thus lead to overheating. The fuel/oxidiser ratio changing with reduced pressure could also make the combustion run hotter (running a car engine lean can lead to overheating, as another example. There the incoming fuel charge is part of the cooling of the piston and valves - running lean tends to burn valves first).
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
Re: Astronomy and Space
SN8 has a separate smaller fuel tank for re-entry because the large tank fuel would slosh around.Grumble wrote: ↑Thu Dec 10, 2020 4:30 pmOk, cooling the nozzle and preheating the fuel makes sense. Judging by the size of the bang there was plenty of fuel, and probably oxidiser, left so I wonder why pressure dropped.dyqik wrote: ↑Thu Dec 10, 2020 4:16 pmThe fuel and oxidiser are commonly circulated in pipes around the combustion chamber to cool it before they are fed into the chamber, so yeah, it could be for heat transfer reasons.
And the low fuel/oxidiser pressure would reduce the amount of cooling, and thus lead to overheating. The fuel/oxidiser ratio changing with reduced pressure could also make the combustion run hotter (running a car engine lean can lead to overheating, as another example. There the incoming fuel charge is part of the cooling of the piston and valves - running lean tends to burn valves first).
Also the re-entry fuel has to be kept colder for longer. It may have only been 6 minutes in this case, but normally it would be a lot longer between launch and landing.
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
From my understanding the engine started to run oxidiser rich, as there was a problem with the methane tank being tested. Hot oxygen with nothing to burn decided to the eat the engine instead, including copper alloys. Green flames, not enough thrust to stop it + hard pad = RUD.
Re: Astronomy and Space
RUD? Even urban dictionary isn’t giving me anything. Thanks for the extra detail though.bjn wrote: ↑Thu Dec 10, 2020 9:00 pmFrom my understanding the engine started to run oxidiser rich, as there was a problem with the methane tank being tested. Hot oxygen with nothing to burn decided to the eat the engine instead, including copper alloys. Green flames, not enough thrust to stop it + hard pad = RUD.
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
Re: Astronomy and Space
Rapid unscheduled disassembly. Originally a joke, Space X actually use the term in their communications.
Re: Astronomy and Space
Mid Air Passenger Exchange. To be avoided.
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Re: Astronomy and Space
Re: Astronomy and Space
I'd assumed it was a nod to the culture novels?
Re: Astronomy and Space
I'd guess that working directly with NASA for crewed vehicles means that they are being more staid about the naming.TimW wrote: ↑Fri Dec 11, 2020 7:25 amNah, it just seems to be a Musk thing. The Boring Company, Tesla models, Falcon Heavy, I assume there are more.
Re: Astronomy and Space
Or that they are launching satellites for DOD, which is not known for its sense of humor.
Re: Astronomy and Space
To be fair, Bragg did more to ensure the defeat of the Confederacy than most Union generals.
And remember that if you botch the exit, the carnival of reaction may be coming to a town near you.
Fintan O'Toole
Fintan O'Toole