E-6B Mercury

The E-6B Mercury is a strategic airborne command post and communications relay aircraft, based on the Boeing 707 airframe. It provides a survivable communications link to the United States' nuclear triad, capable of launching intercontinental ballistic missiles and communicating with ballistic missile submarines.

Developed in the United States, the E-6B entered service in 1998, evolving from the E-6A to enhance its command and control capabilities for nuclear deterrence.