The E-6 ABNCP modification program was established to upgrade TACAMO operational capabilities by incorporating a subset of United States Strategic Command (USSTRATCOMM's) EC-135 ABNCP equipment into the E-6 aircraft. The modified aircraft have the designation changed from E-6A to E-6B. The E-6B modified an E-6A by adding battlestaff positions and other specialized equipment. 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 US land based intercontinental ballistic missiles. The E-6B is capable of performing both the TACAMO and ABNCP missions. This modification enables USSTRATCOM to perform current and projected TACAMO and ABNCP operational tasking using the sixteen dual mission E-6B aircraft. The E-6B provides survivable Command Control & Communications (C3) force management communications for the NCA via multiple frequency band communications. The E-6B was conceived as a replacement for the Air Force's Airborne Command Post due to the age of the EC-135 fleet. The first E-6B aircraft was accepted in December 1997 and the E-6B assumed its dual operational mission in October 1998. The E-6 fleet will be completely modified to the E-6B configuration by the year 2003.
Nuke launcher in the sky. Doomsday.
https://fas.org/nuke/guide/usa/c3i/e-6.htm