At a launch site deep in a pine forest in central Ukraine, five men in balaclavas removed a camouflage cover from a lightweight replica of a Russian-made Shahed drone. “Pull!” one man shouted, and the winged, triangular drone flew up over the trees.
Standing nearby was a miniature black rocket with four propellers. This was the P1-Sun Long, one of Ukraine’s first interceptor drones powered by artificial intelligence. Trained to find and knock down Shahed-type aircraft, it, too, took off.
The P1-Sun reflects both the Ukrainian military’s embrace of A.I. and the rapid evolution of its defenses against Shaheds. Russia fires the drones — essentially flying bombs — into Ukrainian cities in relentless daily waves, destroying infrastructure, killing civilians and sowing terror.
Earlier in the war, Ukraine relied mostly on heavy machine guns, electronic warfare and occasionally missiles to bring down Shaheds. Last August, the Ukrainian military began to widely deploy interceptor drones piloted by humans, without A.I.
Now, a major Ukrainian drone manufacturer, SkyFall, which conducted the recent test in the forest, says its interceptors have made dozens of A.I.-assisted strikes on Shahed-type drones since November, among thousands of interceptions overall.
The interceptor drones are among a range of A.I.-powered weapons that have been deployed in recent months after being trained on the immense troves of data that the war has produced.
These weapons include unmanned ground vehicles equipped with machine guns that use A.I. to help them quickly identify small quadcopters known as F.P.V. drones, because of the first-person view they offer to remote pilots. A.I. is also used in so-called terminal guidance systems, in which a weapon locks onto a target in its final approach and completes its strike without further human intervention.
Many A.I. systems under development can autonomously identify objects like enemy vehicles. Some, in a more sensitive potential application, can single out people, like enemy soldiers. SkyFall is among those quietly testing people-targeting capabilities in Ukraine.
A.I. developers and Ukrainian leaders say they are aware of the risks as the war spawns a technological revolution. As an era of fully autonomous lethal weapons approaches, human rights groups say that reducing life-or-death decisions to an algorithmic calculation is a threat to humanity.
At the same time, Ukraine is eager to use any technology that can increase its interception rate against Shaheds, and that means turning to highly automated air defenses.
As of now, A.I. does only part of the work. Humans remain involved in critical aspects.
SkyFall’s A.I. system has been trained on more than 10,000 videos of interceptions of Shaheds. According to Brave1, a Ukrainian government defense technology hub, dozens of companies are using the videos to train A.I. systems to recognize Shaheds.
SkyFall also regularly conducts exercises using replica targets, but it could not possibly fly enough decoys to fully train the system.
During the recent demonstration in a small forest clearing, the pilot of the SkyFall interceptor, holding a remote control, guided it into the sky. The A.I. system was first to detect the Shahed decoy, long before the pilot could have. It marked the target with a green square on the pilot’s screen.
The pilot flew the interceptor drone toward the decoy until its shape was clear on his screen. Then he gave the auto-targeting system an order to follow it, and he let go of the controls.
Once the interceptor had steered itself close enough to hit the Shahed, the pilot gave a final order, pressing the button to go in for the kill.
The goal of the A.I.-driven system is to significantly shorten the time needed to detect and track enemy drones.
Recently, the Ukrainian defense minister, Mykhailo Fedorov, said that a company participating in the Brave1 program had created a technology that automated 95 percent of the interception process.
This system cannot yet initiate a launch automatically. It takes over, Mr. Fedorov said, after an operator selects a target and authorizes engagement. From there, it independently guides the interceptor toward the Shahed, autonomously identifies it and homes in. The company is MaXon, a defense technology start-up founded early last year.
With even more autonomy, interceptors could stand ready to launch automatically after radar detects an attack. SkyFall says it is testing such a system.
The advances may eventually allow one pilot to oversee several missions, instead of just one at a time, as is the case now, helping Ukraine’s outmanned military.
In part because of its personnel shortages, Ukraine is producing a wide range of aerial, sea and land drones. The hundreds of companies producing the drones aim to make them as inexpensive and as automated as possible.
According to the head of autonomy and computer vision for SkyFall, who asked not to be named for security reasons, his company alone can make 50,000 interceptors a month. A bigger challenge is training enough skilled pilots; they remain on duty around the clock.
Ukraine and other countries require highly autonomous systems to be able to operate at scale. Such development is important to Ukraine not just for its own defense, but also for its hopes of becoming a major defense exporter.
After the United States and Israel began their war against Iran this year, those two countries and Persian Gulf nations used hundreds of costly interceptor missiles to shoot down inexpensive Iranian-made Shaheds. Ukraine quickly offered its cheap interceptor drones, without A.I. systems, as an alternative.
Several Ukrainian companies have introduced remote-control technologies that allow missions to be piloted from Kyiv. Such offerings have helped Ukraine’s president, Volodymyr Zelensky, cut security deals with Gulf states.
In return, Mr. Zelensky has hoped to receive U.S.-made Patriot air defense systems, which Ukraine needs to shoot down Russian ballistic missiles.
The Ukrainian leader has acknowledged the perils of A.I.-powered weapons, saying, “It’s only a matter of time — not much time — before drones are fighting drones, attacking critical infrastructure and targeting people all by themselves.”
Weapons are evolving faster than humanity’s ability to protect itself, Mr. Zelensky said in a speech to the United Nations General Assembly in September. As A.I.-enhanced drones got cheaper and proliferated, even small terrorist groups and cartels would use them in attacks, he said.
Officials at companies like SkyFall and military commanders continue to stress the need for human confirmation before completing a kill. But at this point it is clearly an ethical, rather than a technological, limitation.
The forest tests also involved applying A.I. to help F.P.V. drones find targets — both equipment and personnel — on the ground.
As a dark green minivan drove in and out of the trees, a pilot designated points near it as a target. The A.I. automatically adjusted its aim onto the vehicle.
In addition, the exercise involved identifying potential human targets: Members of the team walked around the clearing pretending to be Russians.
Developers from SkyFall, eating sandwiches and cookies, watched on a monitor while a drone’s A.I.-assisted targeting system located a colleague whose call sign was Forest. The system locked in on him and waited for the pilot’s order to strike or stand down.
