From one SR-71 memoir I remember the factoid that sometimes the electromechanical star tracker was sensitive enough to catch stars in the daylight while the pla

From one SR-71 memoir I remember the factoid that sometimes the electromechanical star tracker was sensitive enough to catch stars in the daylight while the plane was still on the ground. Makes one wonder what is possible now with modern digital photographic sensors and processing power. And miniaturisation of course, the 60s celestial navigation unit was the size of a fridge.