08-07-2025
How old-school tech is rewiring drone warfare in Ukraine
DOBROPILLYA, Ukraine—The drone slipped under a bridge and edged toward a human-shaped object resting on a platform inside one of its cement supports.
Through its camera, the Ukrainian pilot saw a sleeping Russian soldier wrapped in a red blanket, apparently oblivious to the deadly machine buzzing beside him.
The ambush that killed the Russian last month was only possible because the drone was guided by a fiber-optic cable that allowed the pilot to maintain a direct connection behind the tons of concrete.
Such ingenious attacks are taking place across the east of the country, where Ukraine is trying to blunt Russia's grinding advance with a new generation of quadcopters steered by long coils of ultrathin and highly versatile wire.
As Russia and Ukraine battle to gain an edge on the battlefield, fiber-optic drones are a distinctly old-school response to the way both sides have used electronic warfare and physical barriers to make most ordinary craft ineffective. Instead of using radio signals that can be easily blocked, fiber-optic drones transmit data back to the pilot through the cable they unspool as they fly.
'If it wasn't for those drones, I'm not sure what I'd be doing right now," said a top pilot with Ukraine's 68th Brigade's Dovbush Hornets, which carried out the bridge ambush that killed several Russians. 'Fiber optics is a lifeline."
The rapid pace of technological innovation that has accompanied the war makes the arrival of fiber-optic drones seem like a logical development.
A shortage of artillery shells since 2023 has forced Ukraine to increasingly rely on millions of so-called first-person-view—or FPV—drones, which are equipped with a camera and a small explosive to take out enemy soldiers, weapons caches and armored vehicles.
But their reliance on radio signals has made them an easy target for electronic-warfare systems positioned all along the 600-mile front line and mounted atop vehicles across eastern Ukraine.
A new solution was needed. That is where fiber-optic drones came in.
On first glance, they resemble traditional wireless quadcopters. But a box strapped to the fiber-optic drone contains a coiled length of cable, usually up to 20 kilometers long, of the type used to power high-speed internet access. This line forms a link between the drone and a guidance device on the ground.
During flight, the cable is unwound and released through a small opening in the box, ensuring an airtight connection between the device and its pilot. The drones can then be deployed at the beginning of a combined attack to disable Russian electronic-warfare systems and pave the way for squadrons of radio-guided drones to decimate the enemy position.
Fiber-optic drones are a gamechanger in built-up areas, where walls or ravines interfere with radio signals. A skilled pilot can maneuver a fiber-optic drone around obstacles and strike the enemy where it least expects to be reached, destroying armored vehicles positioned on low ground or deep in the forest. They can also fly into buildings and wait for the appropriate target, or enter a garage or hangar and ambush the first Russian tank that drives in.
'You can park this drone on the ground and simply wait for a vehicle to come," said Michael Kofman, a defense expert at the Carnegie Endowment for International Peace. 'This is a logical adaptation considering how drones and electronic warfare have been evolving over the course of this war—one countering the other."
The Dovbush Hornets, a unit named after an 18th-century Ukrainian outlaw, now fields one of the army's best drone teams. The 32-year-old pilot, who goes by the call sign 'Respected," spent months trying to adjust the frequencies of radio-guided drones to evade Russian electronic warfare, achieving unimpeded flight for brief periods before the Russians tapped the same wave.
On missions inside Pokrovsk, a city once home to 80,000 people, the quadcopters launched by Respected's unit barely left the ground before they lost signal and became inoperable.
Members of the Achilles Drone Regiment in the Kharkiv region of drones transmit data back to the pilot through the cable they unspool as they fly.
The fiber-optic drones they began receiving in the spring had no such issues.
Respected, an avid videogamer from Lviv who was mobilized into the army while out walking his dog in his pajamas in the fall of 2022, found that the new drones could maneuver around hard obstacles without losing signal.
His unit used them to kill a group of Russians hiding inside a length of metal piping near a construction site close to the front line. In another mission, they flew inside an abandoned school and destroyed vast stores of equipment left by Russian soldiers.
One video posted online showed Russian troops using wooden batons in a futile effort to knock out a fiber-optic drone. In another clip, a Russian emerges from a forest hideout after a fiber-optic drone flew past and films himself using heavy-duty scissors to cut the cable, causing the drone to crash.
'They create an effect of terror when you know there is no escape," said Lt. Andriy Kasianenko, a company commander in the Achilles Drone Regiment. 'You can be reached in buildings, in low-lying areas, anywhere."
Tethered weapons aren't a new concept. Germany developed wire-guided air-to-air missiles during World War II and wire-guided antitank missiles have been in service for decades.
Russia was the first to use fiber-optic drones in the war and deployed them successfully during its offensive to retake parts of the Kursk region last fall. During the fighting, some Russian pilots idled their drones by the roadside, waiting for Ukrainian vehicles to pass by before chasing them down the road and destroying them.
Ukraine has raced to catch up with the Russians. It has started training its troops on the new technology, which it had experimented with earlier but never implemented in combat.
In an age of wireless connectivity, Ukraine realized the weapons represent both a leap forward and an anachronism because cables make drones more unwieldy and often slower. The wire can veer off course in heavy wind or break if it gets twisted over a tree line or built-up area. Tanks and other vehicles with tracks can snap the cable if they drive over it, severing the drone's connection to the pilot.
Before launching one recent flight, Respected's unit asked pedestrians in a busy shopping area to take a circuitous route on their morning errands to avoid interfering with the cable. Respected says the cable still snaps on half the flights he launches.
It is also heavy. Most drones can carry a weight of 3 kilograms in flight, but a box containing 10 kilometers of fiber-optic cable spool weighs around 1.5 kilograms, limiting the payload they can carry.
'The longer the cable, the bigger the drone needs to be," said East, a pilot in Kasianenko's unit. 'But the bigger the drone, the easier it is for the Russians to stop and shoot it."
When a fiber-optic drone reaches its target and detonates, the wire that trailed it remains on the ground. Miles of fiber-optic cable now cover roads and fields throughout eastern and southern Ukraine. Soldiers have posted videos of themselves tripping over wire as they trek through fields. One photographed a bird's nest made out of discarded fiber-optic cable.
It isn't just a long-term environmental issue. Ukrainian soldiers say enemy troops can fly reconnaissance drones and track a line of cable back to the position from where it was launched.
'With fiber optics, it is better to launch a drone and move from the location after the operation is done," said East. 'It is far too easy to track."
The introduction of fiber-optic drones has had such an impact that both sides are scrambling to increase their production while seeking to hobble each other's ability to do so.
Sparrow Avia, one of the largest Ukrainian drone factories, says it is overwhelmed with orders from the military.
'Demand is colossal," said Nikolai, the director of the enterprise, whose 220 employees work from a secret location west of Kyiv. That is despite the fact that fiber-optic drones cost around double the price of normal FPV drones, which are priced at around $500.
Sparrow Avia produces 12,000 fiber-optic drones a month, Nikolai said, and is working to fulfill orders placed a year in advance. 'We're not keeping up," he said. He plans to be producing 20,000 by the end of the year.
In a large section of the plant, automated machines wind spools of fiber-optic cable that are then placed inside cylindrical boxes. The process is becoming more streamlined. It used to take 60 minutes to wind 15 kilometers of cable, Nikolai said—now it takes 20.
Sparrow Avia is also experimenting with green fiber-optic cable that will blend into the verdant surroundings of eastern Ukraine during summer and fall.
His company has invested in pioneering the production of optical cable in Ukraine, using machine tools ordered from abroad. But for now, the company's reliance on China makes it vulnerable.
'If China was to stop deliveries of this cable to us, then all fiber-optic flights in Ukraine would instantly stop," he said.
Meanwhile, Ukraine is trying to level the playing field with Russia. Twice this year, it has struck Russia's only factory producing fiber-optic cable in Saransk, according to Ukrainian officials and open-source intelligence analysts. Russia hasn't confirmed the attacks.
Kasianenko, the Achilles company commander, said these drones will continue to be used for specific targets ordinary drones cannot reach, paving the way for radio-controlled munitions to attack.
To counter them, he and other Ukrainian commanders envision a future where fields near the front line are dotted with scissor-like devices jutting out of the ground and primed to cut through any fiber-optic cable that falls between their razors.
But by that point, the technological revolution will likely have moved on with AI-guided quadcopters locking on to targets on their own and changing frequencies to ensure they are not disabled.
'All radio-controlled frequencies for most drones will eventually be completely jammed," Kasianenko said. 'Soon, auto-guidance systems will be the future."
Until then, the telltale wisps of fiber-optic lines will blanket swaths of the front line, enveloping fields and devastated towns like a vast spiderweb glistening under the sun.
Write to Matthew Luxmoore at
