‘Here’s a news item you may have missed over the holidays. The “doomsday planes” are being upgraded. Four E-4B flying command posts that would be used by U.S. leaders to manage military operations in a nuclear war will receive communications upgrades to enhance their “connectivity” during a conflict that could spell the end of civilization as we know it.’
via A Doomsday Plane Reminder: Nuclear Weapons Haven’t Gone Away.