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Why does SpaceX load the LOX first?
http://www.spacex.com/Maiden_Flight_Overview.pdf
They must have some good reason that makes it worthwhile to boil off as much LOX as they can before launch, right? Does anyone know what it is? |
#2
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Why does SpaceX load the LOX first?
richard schumacher wrote:
http://www.spacex.com/Maiden_Flight_Overview.pdf They must have some good reason that makes it worthwhile to boil off as much LOX as they can before launch, right? Does anyone know what it is? I don't know so i guess, chill structures to prevent thermal stresses? And rp-1 can't be pumped in because of the common bulkhead thing until just before launch (it'd warm up the lox). And you can't do the opposite because of some thermal stress issues? It's also noticeable that the second stage filling takes longer and is started earlier, both for lox and rp-1. Page 12 has a hilarious picture of the satellite in the shroud. The fairing isn't big, but that payload is such a tiny tiny cube, 30 cm a side, that it feels the rocket is launched empty... Of course, with their "cheap" price, it makes sense, but it's also a dod sponsored test launch the way it is (someone can argue against this). |
#3
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Why does SpaceX load the LOX first?
"meiza" wrote in message ... richard schumacher wrote: http://www.spacex.com/Maiden_Flight_Overview.pdf They must have some good reason that makes it worthwhile to boil off as much LOX as they can before launch, right? Does anyone know what it is? I don't know so i guess, chill structures to prevent thermal stresses? And rp-1 can't be pumped in because of the common bulkhead thing until just before launch (it'd warm up the lox). And you can't do the opposite because of some thermal stress issues? It's also noticeable that the second stage filling takes longer and is started earlier, both for lox and rp-1. I spoke to our SpaceX "expert" at work (he's responsible for tracking their activities) and he tells me it's so they can finish propellant loading almost simultaneously late in the count. It takes longer to load the LOx, so they start with it, then begin RP-1 load. When both systems are loaded, the count is generally down around T-25m or so. Sorry for the late answer. |
#4
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Why does SpaceX load the LOX first?
In article ,
"Kim Keller" wrote: "meiza" wrote in message ... richard schumacher wrote: http://www.spacex.com/Maiden_Flight_Overview.pdf They must have some good reason that makes it worthwhile to boil off as much LOX as they can before launch, right? Does anyone know what it is? I don't know so i guess, chill structures to prevent thermal stresses? And rp-1 can't be pumped in because of the common bulkhead thing until just before launch (it'd warm up the lox). And you can't do the opposite because of some thermal stress issues? It's also noticeable that the second stage filling takes longer and is started earlier, both for lox and rp-1. I spoke to our SpaceX "expert" at work (he's responsible for tracking their activities) and he tells me it's so they can finish propellant loading almost simultaneously late in the count. It takes longer to load the LOx, so they start with it, then begin RP-1 load. When both systems are loaded, the count is generally down around T-25m or so. Sorry for the late answer. No indeed, thanks! So in fact they're not boiling off more than necessary. I had assumed that they would load the propellants sequentially, for simplicity or safety. |
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