Beam weapons never run out of ammunition, but physics keeps blurring their aim
A directed-energy weapon hits with focused energy instead of a bullet, whether that means laser light, microwaves, particle beams or sound. Its appeal is simple arithmetic: a British radio-wave system unveiled in 2024 reportedly costs under 10 pence a shot. Yet after decades of work, most such weapons remain experimental.
The advantages read like a wish list. Light moves at light speed and ignores gravity, wind and the Coriolis effect, so it flies almost perfectly flat and can strike anything in line of sight. Beams outside the visible spectrum make no sound and cannot be seen. As long as there is electricity, there is nothing to reload, which removes a whole supply chain, and in some settings each shot is far cheaper than a missile.
Nature pushes back. Diffraction and spreading dilute a beam over distance, and dust, moisture and air absorb or scatter it. Particle beams suffer a problem called blooming: in any beam, particles jostle one another and collide with air molecules, and in charged beams ions of like charge also repel each other, so energy that should land on one spot smears out. Practical particle-beam weapons have yet to be demonstrated. Even fighter radars proposed as missile killers turn out to be lethal only within about 100 metres.
Microwaves have found the clearest role, frying or confusing electronics. Raytheon announced Vigilant Eagle in 2005 to steer shoulder-fired missiles away from airliners with microwaves, and shoulder-held anti-drone devices shaped like rifles jam the links a drone uses to navigate and talk to its pilot, so it drops out of the sky. Queensland police carried such guns while guarding the 2018 Commonwealth Games. On the laser side, Britain's DragonFire, reportedly in the 50 kW class, has been trialled against drones and mortar rounds, with ships, aircraft and vehicles due to carry it from 2027.
Many countries, including China, France, India and Israel, are developing such systems, and Turkey claimed the first combat use, in Libya in August 2019. American missile-defence versions are not expected before the mid to late 2020s.
Source: Directed-energy weapon
