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0 pointsmikro2nd9y ago0 comments

Interested to know more about the fuels... when I searched for info about Falcon-9 fueling a week or two ago (having briefly conceived of a semi-idle interest in rocket propellants) I read it was RP-1 plus oxidiser - so basically "just" high-spec kerosene. That doesn't jibe with supercooling in my mind... Please enlighten us further.

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Tuna-Fish9y ago

They chill the fuel and oxidizer to slush, just above their freezing point, to fit more of it into the same volume and save on structure.

angryspacesheep9y ago

How many Falcon 9s have been launched using this fueling method?

ygra9y ago

As far as I know that was one of the defining changes of the Falcon 9 Full-Thrust, which flew first in December 2015 with Orbcomm OG2 M2. So, every Falcon 9 this year, plus one.

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TrevorJ9y ago

At least the last two launches, off the top of my head.

Retric9y ago

Liquid O2 aka oxygen is a common and cryogenic oxidizer. Loading cold liquid fuels also has benefits like lower volume, but few things stay liquid at cryogenic temperatures.

PS: When dealing with rockets oxidizer is also a fuel because they need both it and something to burn.

DigitalJack9y ago

For oxygen to be liquid it needs high pressure and low temperature.

shoegumfoot9y ago

Actually, atmospheric pressure is enough, and oxygen boils at a slightly higher temperature than nitrogen.

DigitalJack9y ago

thanks, I should have said "or."

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0 pointsmikro2nd9y ago0 comments

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Tuna-Fish9y ago

They chill the fuel and oxidizer to slush, just above their freezing point, to fit more of it into the same volume and save on structure.

angryspacesheep9y ago

How many Falcon 9s have been launched using this fueling method?

ygra9y ago

As far as I know that was one of the defining changes of the Falcon 9 Full-Thrust, which flew first in December 2015 with Orbcomm OG2 M2. So, every Falcon 9 this year, plus one.

1 more reply

TrevorJ9y ago

At least the last two launches, off the top of my head.

Retric9y ago

Liquid O2 aka oxygen is a common and cryogenic oxidizer. Loading cold liquid fuels also has benefits like lower volume, but few things stay liquid at cryogenic temperatures.

PS: When dealing with rockets oxidizer is also a fuel because they need both it and something to burn.

DigitalJack9y ago

For oxygen to be liquid it needs high pressure and low temperature.

shoegumfoot9y ago

Actually, atmospheric pressure is enough, and oxygen boils at a slightly higher temperature than nitrogen.

DigitalJack9y ago

thanks, I should have said "or."

j / k navigate · click thread line to collapse