Every time we post a video about drones, radios, satellites, autonomous weapons and anything with a circuit, there are always people in the comments who say something like “Worthless, an EMP will take it out.”
Electromagnetic pulses, or EMPs, have been part of doomsday scenarios for decades. They pop up in television, movies and video games with catastrophic and often unrealistic effects. While EMPs are very real, they’re not the magic wands that can bring an entire country and its military to its knees.
What is an EMP?
As the name implies, an electromagnetic pulse is a burst of electromagnetic energy that can disrupt or damage electronics. Three phases make up an EMP, and there are three main types of EMP. First, the phases, and we’ll use their enlisted equivalents to help explain:
- E1 – Like an actual E-1 that just showed up, this is high energy and capable of incredible destruction. This phase is rapid, measured in nanoseconds, and typically fries microelectronics like processors, avionics, radios, and anything with delicate circuitry that is sensitive to variations in power. The smaller and more efficient the device, the more vulnerable it is.
- E2 – This phase is most like a lightning strike. It is a little slower than E1 and more deliberate, but it can still ruin your day and potentially week. Most gear with surge protection can handle it, but unprotected antennas, power lines, unsuspecting second lieutenants, and older systems are still at risk of the sudden surge in current.
- E3 – The longest of all three, this low-frequency energy is caused by the distortion of the Earth’s magnetic field. The E3 phase, like its enlisted counterpart, understands that time is undefeated and chooses to wear things down over time. Things like electrical transformers are vulnerable to this phase, making it a significant threat to the power grid.
Depending on the EMP type, you could see just one or all three phases, so let’s explain the types:
- High-altitude EMP (HEMP) – This is typically what most people picture when they hear “EMP attack.” This is created by detonating a nuclear device 30-400 kilometers above the Earth, which then showers objects in space, like satellites, and the surface of the Earth with all three phases.
- Non-nuclear EMP, or NNEMP, is generated by devices like microwave weapons, specialized bombs, and cruise missiles, and is made up primarily of the E1 phase. These are localized and intense, designed to fry microelectronics without causing kinetic damage. Weapons like the CHAMP cruise missile and the Air Force’s THOR microwave anti-drone system are examples of NNEMP, and have become more relevant as small drones take over the battlefield.
- Finally, there are solar flares, or Coronal Mass Ejections (CME). These are not man-made like HEMP and NNEMP, but are still a significant threat. CMEs are the result of space weather events on the surface of the sun that eject charged particles toward Earth. The famous 1859 Carrington Event and the 2022 solar flare that took out 38 Starlink satellites are solid examples of what happens when this long-duration E3 blast occurs.
Starfish Prime
In 1962, the United States conducted a secret nuclear test called Starfish Prime. From a remote location in the Pacific Ocean, a nuclear missile topped with a 1.4 megaton bomb was launched and detonated 250 miles above the Earth as part of Operation Fishbowl.
The idea was to see if high-altitude detonations could be used for ballistic missile defense or to disrupt enemy communications. Scientists had theories as to what would happen, but nobody knew what the true outcome would be.
The results surprised most involved. Roughly 900 miles away in Hawaii, about 300 streetlights were knocked out. Burglar alarms were set off. Several satellites, including the Soviet Cosmos 5, were damaged or destroyed by the artificial belt of radiation left lingering in space for months.
Starfish Prime didn’t plunge us into a dystopian worldwide blackout, but it was enough to convince both the U.S. and Soviet Union to start hardening their nuclear command-and-control systems against EMP effects. It also helped spur the 1963 Partial Test Ban Treaty, which banned nuclear tests in the atmosphere, space, and underwater.
How bad could it be today?
Most of America’s civilian infrastructure is not hardened against EMPs. Aging transformers, vulnerable SCADA systems, and our reliance on GPS for both navigation as well as timing for our networks make us especially susceptible to the effects of an EMP, whether that’s man-made or courtesy of the sSun.
The military isn’t as susceptible, but it’s also not invincible to EMP as some may believe. Strategic systems like ICBM launch sites, nuclear bombers like the B-2 and B-52, and deep bunkers are built to survive EMP effects in a nuclear war.
Tactical gear like vehicles, radios, GPS receivers, and engine control units are vulnerable. In 2017, AM General pushed the Humvee as an EMP-resistant option for the military due to its lack of technology and circuits, but other platforms aren’t as resilient. Aircraft that rely on fly-by-wire and sophisticated avionics, which is most at this point, could require significant repairs depending on the strength of an EMP. Drones, loitering munitions, and other small electronics are extremely susceptible to the threat of E1 pulses.
Navy warships and their steel hulls are naturally and artificially hardened against the effects of an EMP. Most of the sensitive electronics are surrounded by steel, forming a Faraday cage-like shelter over them, but any loss of navigation and communication aids could degrade their effectiveness.
Recovery of many assets could take days to weeks, depending on what was damaged and the availability of spare parts.
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How prepared is the U.S. military?
In 2016, the Government Accountability Office released a report to Congress with its assessment of federal efforts to reduce the risk from EMPs. It found some notable issues. One was that the Department of Defense had no department-wide policy to cover EMP protection across all services and mission areas. Testing was only being conducted on strategic assets and not across the force. A big revelation was that the DoD hadn’t fully assessed how EMP effects on civilian infrastructure, like power and communication networks, would affect military readiness.
In 2019, the White House issued an Executive Order to harden systems against EMPs, calling for risk assessments, EMP-resistant technology, and a national response strategy. In 2022, the Department of Homeland Security (DHS) published best practices discussing shielding, surge protection, and testing —— but it was all non-binding. Currently, it isn’t clear if any steps were taken in response to the Executive Order or the DHS report, so those problems discovered in 2016 could still apply to today.
The bottom line
Could an EMP knock out satellites or disrupt battlefield communications? Absolutely. Would it collapse the U.S. military overnight? Not likely. Strategic systems are hardened, and tactical systems can be repaired or replaced. And, as we go more in-depth on YouTube, there’s a big difference between what’s technically possible and what’s strategically likely — especially when the most probable large-scale EMP event wouldn’t come from a nuclear weapon at all, but from the sun.
