AN/DRC-8 Emergency Rocket Communications System

The Emergency Rocket Communications System (ERCS) was designed to provide a reliable and survivable emergency communications method for the United States National Command Authority, using a UHF repeater placed atop a Blue Scout rocket or Minuteman II intercontinental ballistic missile. ERCS was deactivated as a communication means when President George H.W. Bush issued a message to stand down SIOP-committed bombers and Minuteman IIs on 27 September 1991.

Source: Wikipedia — AN/DRC-8 Emergency Rocket Communications System (CC BY-SA 4.0)