Bors, Thanks for answering. I must have been absent from school that day. My thought area was the Hawaiin Islands, but given the distance to Continental US that is a lot of Strats to relay-link just to replace undersea cables. I seem to recall some 2500-3000 miles, to hit US soil- so a 500 mile line of site between Strats would require say 5 Strats as relay duty units, and if you lose any one of those 5 you have a broken chain and no communications.
I would still think from your math two strats could provide 100% coverage and excellent reliability for the Island Chain, ( I looked quick, but a guess using the map scale eyeballed onto the computer screen was maybe 400 miles from tip to tip of the most populated islands). Perhaps a reasonable economic expenditure, but I don't know if the subscribers are there to support the placement. Sure would save a lot of towers and undersea cabling that would be needed.
Anyway thanks for doing math on my question. I have trouble when my electronic dashboard goes to KM instead of MPH! I also like to ask lot's of dumb questions so I can learn enough to ask more involved dumb questions. Every once in a while you can make someone else come up with a bright idea!
Stakddek