A number of military aircraft have incorporated systems as well, and they can be combined with automated celestial fixing systems for a hybrid astro-inertial na

A number of military aircraft have incorporated systems as well, and they can be combined with automated celestial fixing systems for a hybrid astro-inertial navigation system. The SR-71 Blackbird used one, the Nortronics NAS-14V2 [0], and it was pretty amazing for the time (same as everything about the SR-71 granted). Even with a much less accurate INS then this one and primitive computer/star tracker it could maintain high accuracy to enable the precise flight paths and camera activation needed for a spyplane like that to get exact images from 85k feet going Mach 3.2. At altitude an aircraft can always see the stars with the right filter even in the day, which can be used to precisely correct drift. I'm glad this piece itself got some attention, the AIRS system to me is one of the most impressive pinnacles of electromechnical technology and fine machine crafting, feels kind of like the ultimate evolution of efforts dating back to the earliest days of watch making. But there are definitely a range of other systems from the 60s-90s still incredible in their own right but all the more so for what was made to work without all sorts of tools and modeling we take for granted now. And I think ongoing research to allow production of modern such systems at a more mass scale (perhaps a modern AINS using laser or fiber gyros and taking advantage of advancements in cheap quality digital cameras) is worthy of continued effort, just in case. Precise navigation via GPS has become central to an enormous range of modern human activity, but it is relatively fragile and easily jammed. If we can use tech to also create a reasonable fallback that seems like a valuable hedge. ---- 0: https://airandspace.si.edu/webimages/collections/full/NAS-14V2%20ANS%20System.pdf https://airandspace.si.edu/webimages/collections/full/NAS-14...