So, when a CME, or enemy, wipes out most of our GPS birds, will be all be screwed? I gotta believe keeping a working network of VOR (or even the old LORAN navigational system) would be a no-brainer. Can military aircraft even fly without GPS assist? I certainly believe that we have to have a backup. Even our police and fire departments have to have a backup- in our city they have ham radio operators to man the hospitals, squads and fire stations.