NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2026 Aug 8, 09:25 -0700
Hello Dr. Hardy!
Heh. That's a way of saying, please don't call me "Dr. Reed". I appreciate the honorary degree, but just call me 'Frank'.
Yes, the analysis by Linda Mestas is very close to what I would count as the "right way" to puzzle this out. I would modify some details, but I don't think the answer would change much.
You mentioned the "visibility cone of the ISS". I think if you work through that you will discover that this 'cone' distills down to the very large dip of the horizon. Think of the space station as a "tall ship" with an observer height of eye of about 250 miles, zipping along to circumnavigate the globe every 90 minutes. It's rather wonderful that the relatively ordinary principles (if not the tabular methods) of celestial navigation work almost as they would for a surface vessel.
And now some fun. Digging through the NavList archives database last night, I spotted your name: Jurassic NavList.
Frank Reed
