The Lockheed SR-71 reconnaissance aircraft introduced in the 1960s cruised at more than three times the speed of sound. Its extreme speed required extremely precise navigation.
Radio navigation could not be relied upon near hostile territory. And no human could keep pace doing celestial navigation. So the Blackbird relied on the automated Astroinertial Navigation System. Its computer performed the functions of a human celestial navigator, but far faster and more accurately.
Advances in computing made celestial navigation practical for the Mach 3+ SR-71.
Image Date: June 1, 1988
Image Taken: Beale Air Force Base, California, United States
Credit: U.S. Air Force; photo by Tech. Sgt. Michael Haggerty.