TIL The Lockheed SR-71 Blackbird used an Astro-inertial Navigation System to track Stars and determine its position and altitude. At Mach 3, the navigation system was accurate enough to limit drift to 1,000 feet (300 meters) off course.
en.wikipedia.orgSubmitted by shamelessterminator t3_118drfj in todayilearned
Keuleman t1_j9gk38z wrote
Drift... just under 300m. Your captain will be pleased.