Even some military aircraft like the SR-71: http://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-could-be-the-key-to-winning-future-fights-in-gps-denied-envi

Even some military aircraft like the SR-71: http://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-could-be-the-key-to-winning-future-fights-in-gps-denied-environments http://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-coul... Does star navigation work once you’re far beyond locations where we’ve previously been able to map stars from? Or put another way, is our "3D" map of the stars sufficiently accurate, or is it more of a "2D" map. Perhaps you could update the map as you move (SLAM?)