Evan Kirstel TechFluencer on Instagram: "The SR-71 wasn’t just fast—it was impossible by most engineering standards of its time. Built mostly from titanium that had to be imported (secretly) from the USSR, it could fly over Mach 3 for hours—so fast that it outran missiles. The skin expanded in flight from the heat, which is why it leaked fuel on the runway. A machine so advanced that even 60 years later, we’re still trying to catch up. ✈️ #SR71 #EngineeringMarvel #AviationHistory"