It's crazy to me that once they had this high-performance jet fuel, they also used it as a coolant and as hydraulic fluid.<p>I guess the main requirement for the latter two purposes is that it doesn't break down at really high temperatures. The jet fuel needs to be stable at high temperatures too (additionally, you need to be able to burn it to make the engine go) so once you put all this research into finding the right jet fuel you have a liquid that will do OK on the other jobs.<p>Edit: and also it was used for lubrication! Good fuels definitely do not necessarily make good lubricants...it must just be really hard to find anything with the right thermal stability.
I was an inflight-refueling technician in the USAF and there was a variant of the tanker (KC-135T) that had isolated tanks to specifically carry this stuff, for refueling an SR-71. Sadly that was before my time. A neat little factoid tho, I guess.
"Manufacturing several hundred thousand gallons of the new fuel required the petroleum byproducts Shell normally used to make its Flit insecticide, causing a nationwide shortage of that product that year."
> However, very high skin temperatures are generated at this speed due to friction with the air.<p>I remember reading somewhere that this is a common misconception and that most of the heat is generated not by friction but by air compression.<p>But that may have been about the Space Shuttle re-entry, which has considerably higher speeds.
They used two massive Buick V8s to get the turbines started. They eventually switched to Chevy V8s. Another person commented about fuel leaking, it must have been a sight to watch one start up.<p><a href="https://youtu.be/JjdyQpEUYzI" rel="nofollow">https://youtu.be/JjdyQpEUYzI</a>
I've read many years ago that in low temperatures, the SR-71 was prone to leaking fuel while in its hangar. But that was not dangerous because JP-7 won't catch flame without TEB.<p>EDIT: oh yes <a href="https://theaviationgeekclub.com/the-story-of-the-sr-71-blackbird-that-slid-on-jp7-fuel-residue-while-taxing-into-kadena-hangar/" rel="nofollow">https://theaviationgeekclub.com/the-story-of-the-sr-71-black...</a>