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Old July 17th 18, 12:24 PM posted to sci.space.policy
Jeff Findley[_6_]
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Default Soyuz fueling

In article ,
says...

On 2018-07-15 14:34, Jeff Findley wrote:

If you're going to launch (presumably hours) after fueling, keeping the
LOX below the boiling point would be very difficult. Launch vehicles
that do this typically let the LOX boil off and just continuously
replenish with liquid oxygen to make up for the boil off. Most US
launch vehicles have done it this way.


So basically, most launchers get their LOX at just under liquid
temperature and doesn't really warm up over time because the boiling off
process keeps the remaining fuel liquid ?


Yes.

In the case of SpaceX, once they have loaded supercooled LOX, does it
stay put as liquid until it warms up enough for boiling to begin? Or
does boiling happen because of the realitty of Fliorida and the sides of
the tank warming up the supercooled LOX to boiling tempoerature almopst
instantenously, but hopefully keeping the core well below that for long
enough?


As you can see in videos, there is some boil-off. I'm guessing due to
"hotter" areas in the stages like plumbing and etc.

And if there were a delay, how long would it take before the whole tank
warms up to normal "LOX" temperature just under boiling off point?
Minutes? Tens of Minutes? an hour ? hours ?


Google how long their launch windows are. That's your answer.

With regards to Northorp Grunman: The transaction had just been
completed. That Cygnus craft had been launched as Obrital ATK, but was
released from ISS as a Northorp Grunman craft. There is a long period
between the time a merger is announced and the time when the paperwork
is signed and transfer/]urchases of shares executed.


As far as I know, the transaction is complete, hence the reason that the
press is using the new name. According to the NASA page below, the
official acquisition date was June 6, 2018.

https://www.nasa.gov/mission_pages/s...unch/northrop-
grumman.html

From above:

Editor's note:
On June 6, 2018, Orbital ATK, one of the original commercial
resuppliers along with SpaceX, was officially acquired by
Northrop Grumman.

Official enough of a cite for you?

Jeff
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