For the purpose of astro nav:
NP303 is calculated for an epoch of 5 years (and it's only 3 books). Until its end of life, it has to be "updated" in the sense that corrections need to be applied as they are released.
I don't think the point of the books has ever been disaster proofing. For the most part, books were good enough for the job before computers and still are. They're cheap, come from trusted sources (and it's easy to verify that they're legitimate), and they're easy to correct should they have errata.
Windows PCs and excel spreadsheets are used in navigation all the time. Nobody's forcing navigators to use books. If they do, though, they probably have a good reason for it.
For the purpose of astro nav: NP303 is calculated for an epoch of 5 years (and it's only 3 books). Until its end of life, it has to be "updated" in the sense that corrections need to be applied as they are released.
I don't think the point of the books has ever been disaster proofing. For the most part, books were good enough for the job before computers and still are. They're cheap, come from trusted sources (and it's easy to verify that they're legitimate), and they're easy to correct should they have errata.
Windows PCs and excel spreadsheets are used in navigation all the time. Nobody's forcing navigators to use books. If they do, though, they probably have a good reason for it.