In December 1979, Boeing delivered the first E-4B Advanced Airborne Command Post to the U.S. Air Force. The E-4B evolved from the earlier E-4A, of which three were built. By 1985, all A models had been upgraded to B models. Based on the 747-200B, the E-4B provides a highly survivable command, control and communications center in case of national emergency, with “nuclear hardening” to withstand the effects of an electromagnetic pulse from a nuclear blast. All E-4Bs are assigned to the 595th Command and Control Group at Offutt Air Force Base, Neb., with at least one on alert at all times.
The Space Force is playing midwife to a new ecosystem of commercial satellite constellations providing alternatives to the service’s own Global Positioning Service from much closer to the Earth, making their signals more accurate and harder to jam.
