The shuttle is interesting in particular because it is unique is its use of a hydrazine powered APU to pressurize the hydraulics, but I was mainly wondering if anybody could tell me what type of hydraulic fluid it used? Was a special fluid developed specifically for the shuttle? Reason is, I would presume that it might just use ordinary Mil-spec red oils like MIL-H-5606, 83282.
Because of the extreme temperatures experienced by the shuttle though, given the extended cold-soak in orbit, and then extreme heating on re-entry, I think that the Shuttle engineers must have used something higher-performance than a bog-standard Mil-spec red oil fluid - and I'm very doubtful that it used skydrol, which isn't much better! (Blergh)
Red oil fluids have very poor viscosity at extreme low temps, and are flammable at extreme high temps, so did the Shuttle have it's own special fluid? Maybe a silicate ester like Concorde, or maybe even ethylene glycol?
Wingscrubber From UK - England, joined Sep 2001, 858 posts, RR: 0
Reply 2, posted (4 years 4 weeks 1 hour ago) and read 6644 times:
Thanks for that link kalvado - I did wonder if it was 83282 spec fluid - that's one of the higher temperature rated red oils, so it makes sense, I just wondered if there was a special 'space shuttle fluid' used, but that's a regular aircraft grade fluid.