The principle mission of the E-6 Mercury is to connect the national command authority with the U.S. Navy’s nuclear missile force carried aboard at-sea ballistic missile submarines.
The E-6B is a dual-mission aircraft capable of fulfilling either the E-6A mission or the airborne strategic command post mission and is equipped with an airborne launch control system (ALCS). The ALCS is capable of launching U.S. land based intercontinental ballistic missiles.