Timeline for Why does the Falcon 9 consume hydraulic fluid?
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
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| Dec 21, 2015 at 3:21 | comment | added | SF. | Personally, I wonder why not a simpler solution based on a couple of valves: two tanks, one as source of the fluid, the other for return fluid. A pair of valves decides which of the tanks sources the fluid and which collects it, and another pair pressurizes the source tank and depressurizes the return tank. This could actually be driven from a single actuator for the four valves. | |
| May 27, 2015 at 18:34 | comment | added | pbristow | @NickT You are absolutely right - thank you for explaining why the terminology seemed broken in my head. Reason: broken head, not terminology :) | |
| May 27, 2015 at 14:20 | comment | added | Nick T | @pbarranis from what's been described, the nitrogen provides pressure, but the working fluid is a liquid (i.e. hydraulic, not pneumatic) | |
| Jan 15, 2015 at 14:49 | comment | added | pbristow | @slebetman It's definitely a potAto/potaato situation. If they're using compressed gas, like nitrogen, to move the fins directly then just like in an aerosol can, it seems to me to be a propellant. If the compressed gas is pushing a liquid to move the fin, then I guess it's reasonable to say the gas is the propellant and the liquid is a hydraulic fluid. I work in software tho... our industry has no legs to stand on while complaining about misnomers in other industries :) | |
| Jan 13, 2015 at 6:47 | comment | added | slebetman | @pbarranis: Why would you call the fluid that drives pistons to control the rocket's tail fins "propellant"? | |
| Jan 12, 2015 at 7:23 | comment | added | Hobbes | @Anthony, good point. Can you create this as a new question? It deserves more than a comment. | |
| Jan 12, 2015 at 2:55 | comment | added | Anthony X | Could STS SRBs not have used hydrogen peroxide instead of hydrazine? Equally nasty? Lower energy density? | |
| Jan 11, 2015 at 22:14 | vote | accept | pbristow | ||
| Jan 11, 2015 at 22:14 | comment | added | pbristow | Ahh, so obvious! I didn't know an "open system" exists in the hydraulic world, but it makes perfect sense. Of course, calling it "hydraulic fluid" seems like a misleading name. In almost any other field the term would be "propellant". But I digress :) Thanks! | |
| Jan 11, 2015 at 15:55 | comment | added | Organic Marble | The first Delta III launch failed because it ran out of hydraulic fluid ~70 seconds after launch. The engine nozzles were limit cycle gimbaling. | |
| Jan 11, 2015 at 15:35 | history | edited | Hobbes | CC BY-SA 3.0 |
added references
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| Jan 11, 2015 at 15:22 | history | answered | Hobbes | CC BY-SA 3.0 |