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Questions tagged [sub-cooled]

Cooling liquid propellants well below their boiling point - increases density and other benefits.

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How do they know how much liquid propellant is in a rocket just before launch?

In this answer I wrote: In other words, a few tons here or there could depend on something as simple as the weather, or trying to squeeze a little extra propellant in for a given mission with a ...
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What about recycling the helium used for sub-cooling the LOX in the tank of a rocket before launch?

Helium is a rare and expensive noble gas. When it is loaded into a rocket to be used after launch, it is not possible to recycle it. But the helium used for sub-cooling the LOX before launch (see ...
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Why would sub-cooled LOX tanks need to “topped-off” until the last minute or so?

Here is my understanding, let me know if I've got it right or wrong: Until recently, most cryogenic propellants were at or close to their boiling points. Each unit of heat leaking into the tank would ...
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Could super-cold LOX be used in every rocket engine?

Super-cold LOX gives advantages in performance for a rocket. But it isn't used in all rockets. SpaceX's Merlin 1D rocket engine uses super-cold LOX. Also NK-33 use sub-cooled LOX. Could super-cold LOX ...
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Can SLS use subcooled LOX?

The SpaceX Falcon 9 FT is using subcooled liquid oxygen. I understand that LOX gets significantly denser at lower temperatures so more propellant can be filled in the rocket's tank. Can NASA SLS RS-...
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Liquid Helium (4.2K) sealed, then raised to sub-LOX temperature (~70K) - what is the new pressure?

In this question there is discussion of the large differences in temperature between liquid helium-4, subcooled liquid oxygen (sub-LOX) and cold kerosene (RP-1). Approximate temperatures are 4.2K, ~...
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How (actually) do sub-cooled propellants reduce cavitation within turbo pumps and make feed easier?

Starting at about 32:38: "We sub-cool the oxygen and methane to densify it, so compared to... propellants normally used close to their boiling point in most rockets, in our case we actually load ...
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Autogenous pressurization with sub-cooled propellant

In his IAC 2016 talk, Elon Musk said (at 28m 4s in the video) that the ITS booster tanks would use autogenous pressurization. This means there is gaseous oxygen resp. methane in the tank. To stay ...
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Is the “cryogenic helium” system in recent discussions actually LHe for cryopumping?

I am wondering if the "cryogenic helium" system discussed in articles about the 1-Sept-2016 SpaceX Falcon 9 anomaly (see this answer for a good summary to date) is not actually related to the high ...
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Problems compressing the helium tanks inside the F9 2nd stage LOX tank at the last minute?

A recent "Anomaly Update" dated September 23, 1:00pm EDT by SpaceX, includes the sentence: "At this stage of the investigation, preliminary review of the data ...
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Does the NK-33 engine require subcooled kerosene so cold that it turns to wax?

It was mentioned in this answer and in several other places on the internet that the kerosene fuel used by NK-33 engines needed to be subcooled enough so that it reached the same density as the LOX, ...
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Is the supercooled LOX used in Falcon 9 Full Thrust a first?

One of the changes made to the Falcon 9 v1.1 Full Thrust was using supercooled liquid oxygen at 66 K (-340 F) as well as chilled RP-1. I've seen various claims that this is a first in the industry. ...