Ukraine has cracked the riddle of strange metal "whiskers" that appeared on Russian jet-powered drones striking Kyiv, and they don't appear to be some clever new sensor. They are a simple mechanical detonator, a metal tube, and a rod that, on impact, closes a circuit to set off the warhead, Serhii "Flash" Beskrestnov, presidential adviser, says, ending online guessing about the strange devices.

Photos of Russian drones with long metal prongs jutting from the nose had set off speculation about what they were for. The answer, Flash explains, is low-tech: when the prong hits something, the contact closes, and the charge goes off, with no sensors or electronics.

That simplicity sits against a more worrying trend: Russia is steadily upgrading what its drones carry, from the mix of warheads on the jet-powered Geran-4 and Geran-5 to a new charge designed to sever power pylons.

A contact closes the circuit

"It's all mechanically simple, no sensors or complex detectors," Flash says, commenting on the "whiskers".

It is the kind of crude, cheap fuze that suits a weapon meant to be built and spent in the thousands, where cost matters more than finesse.

Russia upgrades the warheads

Russia's jet drones, now built at roughly 3,000 a month, have become the dominant threat in its nightly campaign. The day when Flash published his "whiskers" post, Russia hit Kyiv with another round of drone strikes, hitting a school, a café, and warehouse buildings across the capital. The children inside the school were in its shelter. Fires broke out across two districts, and one person in the city was wounded.

On 28 September, Russia struck Kyiv's Academy of Sciences, which has a century-old history.

After Russia hits Kyiv’s Academy of Sciences with jet-powered drone, the Kremlin says Ukraine must “pay a price”

On the same day, Dmitry Peskov, Kremlin spokesperson, said Ukraine must "pay a price" for its actions in recent months and calls Russia's intensified strikes "part of this price."

Last winter, eight Ukrainian companies told the defense minister that their interceptors were ready to knock Russia's jet-powered drones out of the sky. They were not. A fast-flying drone is the easy part of the design, while combat testing exposed what the interceptors lacked in key features to chase an evading jet-powered Geran, presidential adviser Serhii Beskrestnov, known as Flash, said in an interview with NV.

Ukraine's answer to Russia's fast, hard-to-stop jet drones was supposed to be cheap interceptors, and last winter, their makers said they had them. But a jet Geran flies 450 to 500 kilometers an hour, up from the Geran-3's 320, varies its speed to slip past defenses, and will dodge harder once interceptors appear.

Catching one takes maneuverability, machine-vision target-lock, and fuel to loiter and search, not just speed, Flash said. Ukraine's cheap interceptors have already downed about half of Russia's slower drones, but the jet-powered systems have stayed a step ahead.

Eight makers said "ready"

At a meeting last winter called by Mykhailo Fedorov, then-defense minister, all eight interceptor makers reported the same thing: "everything's ready, the solution exists, it flies, we tested it, speed is sufficient," Flash recalled.

The mistake, he said, was that no one checked on them week to week. There were also too few jet Gerans in the skies then to test against.

"On the range, they showed: it flies. That was the problem," explained Flash.

Speed is the easy part

The engines are not the obstacle, Flash continues, since they can be bought abroad, and neither is a plane that flies fast in a straight line. The hard part is a machine agile enough to chase a jet-powered Geran, which is far more maneuverable than the propeller kind and will start changing altitude and throwing evasive maneuvers once interceptors appear.

Because an operator's aim frays at such speeds, he said, the decisive pieces are automatic target capture by machine vision and automatic terminal guidance.

"Building a construction that just flies fast is the easiest part," he added.

Mass orders must wait

That is why Ukraine cannot simply order thousands to blanket the country, Flash said: it first needs a proven design that works for any crew, from Security Service specialists to territorial defense soldiers, and is simple to launch, operate, and maintain.

Once such a sample exists, he said, scaling up is only a question of money. Meanwhile, the work is moving: a Ukrainian interceptor recently notched its first kills against jet Gerans and is heading toward mass production.