The E-6 TACAMO Enables America’s Nuclear Deterrent

Equipped to each carry two dozen multiple-warhead Trident II ballistic missiles, the Navy’s 14 Ohio-class submarines comprise the most survivable part of the U.S. nuclear deterrent.  But those subs would be nearly useless without E-6 Mercury TACAMO (“Take Charge And Move Out”) airplanes, which support communications between the submarine force and national command authorities. Since the submarines cannot effectively accomplish their missions without E-6 planes, the U.S. needs to ensure it maintains a modern fleet of aircraft to provide submarines with the ability to receive orders.

Ballistic missile submarines (SSBNs in naval nomenclature) are designed for stealth – to remain undetected — as they roam the world’s oceans. To remain unnoticed, Ohio–class submarines have sound-reducing features, such as insulated propulsion systems and machinery mounted on vibration-damping mounts.  The mobility of SSBNs and the 4,000 nautical mile range of the missiles they carry enhance deterrence against a nuclear assault by assuring Washington has enough weapons and delivery systems post-attack to launch a credible second-strike.

The U.S. Navy operates the E-6 Mercury, the airborne portion of the TACAMO communications system, to ensure survivable communication links between decision makers and the fearsome power of Ohio subs. This aircraft receives, verifies, and retransmits Emergency Action Messages to U.S. strategic forces by communicating on practically every radio frequency. The planes are able to connect with all relevant players in the event of nuclear warning, from ground forces all the way up to Air Force One.

To converse with the SSBN fleet, the E-6 uses Very Low Frequency (VLF) radios and a Long Trailing Wire Antenna. The Trident missiles are assigned targets through secure and constant radio communications links at sea. The E-6 TACAMO is also designed to serve as backup if the Global Operations Center, the nexus for United States Strategic Command, is ever destroyed or incapacitated.

Boeing recently upgraded all Mercury aircraft to the E-6B configuration with added battle staff positions and other specialized equipment. The E-6B is currently undergoing a Service Life Extension Program designed to prolong the useful life of the E-6B to 2040.

To abide by the 2011 New START Treaty, the U.S. will eliminate four launch tubes from each of its 14 SSBNs beginning in 2015 — each sub will have 20 functional launch tubes instead of 24 by the end of 2016. Moreover, SSBN(X), the future submarine program to replace the aging Ohio–class vessels, is expected to only have 16 launch tubes on 12 new submarines – further reducing missile numbers by subtracting four more launch tubes per vessel and eliminating the existence of two subs altogether. These future reductions in the strategic force mean that the U.S. must maintain the power of its nuclear deterrent in the future with fewer warheads and delivery systems.

Subs play an especially critical role in nuclear deterrence because they carry over half of the U.S. nuclear warhead arsenal. The E-6 Mercury is an example of a program that enables the strategic triad as a whole and submarines in particular to be effective.  Since the total number of deployed nuclear warheads and submarines will decrease in the future, the U.S. must at least ensure it provides a modernized TACAMO program to enable the reduced submarine force to communicate effectively. Without an assured means of communication, the strongest leg of the nuclear triad may become the weakest. Upgrades and modernization implemented as a result of this program must maintain the aircraft’s connectivity and survivability. It is a frightening thought that without a successful E-6 Mercury TACAMO program, Washington would not be able to communicate with over half of its nuclear arsenal.