I am probably stating the obvious but it was / is a technological tour de force. The engineering challenges that were over come were immense.
Some years back scientific american did a great article on some aspects on the SR71, one of the challenges the design team faced was that of find a hydraulic fluid that could stand the immense temperatures and still remain a liquid ( not boiling off) and functional.
After trawling many supplies they at last found one who catalogue said they had such a product that could remain a fluid at very high temperatures. The Lockheed team ordered it and when the packaging was removed they had a block of solid powdery material, nobody said it had to be fluid at room temperatures.