With China’s recent hypersonic cruise missile test and its ever-expanding reach in the South China Sea, people wonder if perhaps China is plotting an electromagnetic pulse (EMP) attack on the United States. Problem is, in order to generate an EMP field large enough to cause widespread outages, they would have to toss a multi-megaton nuke over the U.S., and then detonate it at the right altitude. Who thinks that would NOT start World War 3?

 

What Is an EMP?

EMP, or electromagnetic pulse, is a sudden burst of electromagnetic energy. Solar flares are the most common causes of EMP, but those are rarely large enough to cause more than minor disruptions on Earth. Good thing, too, because the right solar flare could knock out the entire Earth’s electrical grid. One old crusty civilian I worked with, blamed solar flares for most of the C-5’s navigation problems. Interestingly, during times of increased solar activity, phantom communication and navigation problems were more abundant. Anyone in maintenance can tell you intermittent problems are the bane of every maintainers’ existence.

advanced airborne command post
A right front view of an E-4 advanced airborne command post (AABNCP) on the electromagnetic pulse (EMP) simulator for testing. (Photo by Sgy Ernie Stone/U.S. Army)

Here on Earth, though, the mechanics of producing large-scale EMPs have only been accomplished through the use of nuclear weapons. Smaller EMP bursts can be produced using energy weapons, but these have a limited range and are more suited to disrupting individual systems or small areas. These non-nuclear EMP (NNEMP) weapons have promise, though.

 

EMP as Weapons

Fifth-gen fighter jets loaded with NNEMP missiles, could conceivably penetrate enemy airspace and target air-defense systems, communications systems, and radar sites. With the right placement, these non-destructive weapons could cripple the command and control functions of an enemy state. Non-destructive is a relative term, however. While there will be little to no physical carnage, electrical systems would be completely destroyed, requiring millions of dollars in repairs. All while having no communications and with no way to track further airspace penetration.

Numerous world powers, including the U.S., Russia, and China, all have some sort of NNEMP research and development programs. For obvious reasons that research is shrouded in secrecy, and very little has been done openly with this. In the 1960s, both the U.S. and Russia were hard at work developing more and more powerful nuclear weapons. During the Starfish Prime tests in 1962, a 1.4 megaton bomb was detonated 250 miles above the earth, roughly between the Marshall Islands to the west, and the Hawaiian Islands to the east. While EMP was already a known side effect of nuclear explosions, the range and effect of Starfish showed that these after-effects were a weapon in their own right.

Starfish prime nuclear test
The Starfish Prime high-altitude nuclear test explosion produced in Operation Dominic on July 9, 1962, yielded 1,450 kilotons. (US Defense Threat Reduction Agency)

Shortly after the explosion, and in the months following, several unintended consequences of the test emerged. In Hawaii, about 900 miles from the detonation area, electrical grids failed, telephone systems were knocked out, and automobiles reportedly malfunctioned. Three satellites in low Earth orbit were quickly disabled, with at least six more failing over the next few months. These later failures were attributed to man-made radiation belts orbiting the Earth as a result of the testing.