There is a another story in Sled Driver that goes along the same lines. Pilots requesting to fly at higher altitutes to show off. Some fighter joke request 50 or 60 thousand feet. He gets cleared and then the SR71 requests 80,000 the controller says and just how do you think your going to climb to 80,000? And the sled driver says “we want to descent to 80,000”.
Oh man - I could listen to/read about Blackbird all night long; and I have. I never had the chance to see one in flight, but saw one at an Edwards AFB air show in 1984 (IIRC). I was awestruck and I probably will never get the chance (in what’s left of my lifetime) to see anything to match it. It was sitting inside a hangar with drip pans all around it catching the gelatin-like fuel that was seeping out of every seam of the fuselage. A serious WTF sight until one hears the reason for it. Seeing it straight on, I instantly recognized a plausible explanation for some of those frequently reported UFO sightings out in the desert back in the day.