On or before Saturday, Russian troops somewhere along the 700-mile (about 1,100-km) front line of Russia’s 40-month wider war on Ukraine detected incoming Ukrainian drones. Specifically: fiber-optic first-person-view drones that send and receive signals via millimeters-thick, but miles-long, spools of optical fiber.
Fiber-optic FPVs are extremely difficult to defeat. The main defense against wireless FPVs, which send and receive signals by radio, is electronic jamming that can ground the drones before they strike. But fiber-optic FPVs can’t be jammed. That’s why both the Russian and Ukrainian armed forces are building more of the fiber-optic models—even though they’re several times more expensive than the $500 wireless models.
But sever a drone’s optical fiber, and it’ll fall from the air. Optical fiber is tough, but it can be broken by bending it 180 degrees. Surgical scissors can also cut right through it—as the Russians were well aware. “Got the scissors?” one hidden Russian asked after a Ukrainian FPV buzzed past, trailing its optical fiber, in a video from the Saturday incident. “Got ‘em,” another hidden Russian responded.
The soldiers hurried from their hiding spot, found the drone’s thin optical fiber—and cut it.
The drone lost its command signal. “It’s falling,” one Russian breathed right before the drone exploded a short distance away.
The circumstances of the Saturday fiber-cutting will be difficult for the Russians—and Ukrainians, for that matter—to duplicate. The soldiers had to have ample warning of the incoming drone raid, opportunity to hide from the passing drone and plenty of luck. If a second drone had followed the first, it might’ve struck the Russians as they tried to scissor the first drone’s fiber.
Cut the cord
Yes, scissors are an effective defense against fiber-optic drones—but only in the most extraordinary circumstances. That’s why both sides are literally digging in, going underground to avoid the millions of FPVs swarming the front as the war grinds into its fourth year.
More and more, armored vehicles and infantry hide indoors or underground when they’re not actively attacking or defending. It’s a new “era of the cautious tank,” according to David Kirichenko, an analyst with the Center for European Policy Analysis in Washington, D.C.
The only scalable active defenses against fiber-optic drones are to shoot them down right before they strike, usually with shotguns. That’s risky, however. Miss with your first shot, and you might not get a second one before the drone strikes.
Acknowledging the difficulty of stopping fiber-optic FPVs right before they explode, the Russians and Ukrainians are trying to stop them “left of the boom,” to borrow a US Army term. That might mean detecting the optical fibers left over from earlier attacks, tracing the fibers back to the drone operators—and bombarding the operators with drones or artillery.
That only works if the operators unwisely linger in the same location long enough for the enemy to hunt them down.
Ukrainian forces are trying to get even farther left of the boom—attacking the factories that produce Russia’s FPVs.
On 13 March, long-range drones belonging to the Ukrainian defense intelligence agency struck a hidden drone manufacturing facility in Obukhovo, just outside Moscow, 300 miles (about 480 km) from the border with Ukraine. A few weeks later, in April, Ukraine sortied one of its then-new Aeroprakt A-22 sport plane drones to strike a drone plant in Yelabuga, 550 miles (about 880 km) east of Moscow.
And on 4 April, a dozen Ukrainian attack drones motored 460 miles (about 740 km) into Russia and struck a factory in the city of Saransk. The target was the Optic Fiber Systems factory, which produces—you guessed it—fiber-optic cables. The critical component in Russia’s best unjammable FPVs.
