Ukraine has employed a new tactic during its major Operation Vivaldi in Donetsk Oblast. During the 3rd Army Corps' offensive, fighters from the world's first experimental unit of unmanned ground-strike vehicles, "NC13", have upgraded their kamikaze ground drones with grenade launchers.

Vivaldi is the counteroffensive the corps is running near Lyman in northern Donetsk Oblast. Over its first two "seasons," the 3rd Army Corps and attached units have retaken more than 125 square kilometers, half of it de-occupied outright, and inflicted more than 3,000 casualties on Russian forces.

Through this offensive operation, the 3rd Army Corps, commanded by Brigadier General Andrii Biletsky, disrupted Russian forces' plans to encircle the fortress-belt cities in Donetsk Oblast from the north and south. Among them are Sloviansk, Kramatorsk, Druzhkivka, and Kostiantynivka. These cities have helped hold back Russian forces since 2014.

From intensive training to the world-first operations

The NC13 unit has been through Bakhmut, Avdiivka, and other of the toughest sections of the front.

Among its achievements: the world's first robotic assault carried out without infantry involvement, resulting in the capture of two Russian soldiers, a sabotage operation in the enemy's rear — blowing up a crossing and disrupting an offensive — using UGVs alone, and Ukraine's first fully robotic defense of a position for 45 days without involving infantry.

"No one in the history of warfare has used this kind of tactic before," the soldiers commented on the offensive.

The defenders say that a lack of combat experience is no barrier to joining the unit. Every recruit goes through an intensive training course led by experienced instructors.

Grenade launchers were developed based on the Soviet RPG-22

During the operation, UGVs equipped with two Bullspike grenade launchers attacked Russian positions, then detonated directly inside their shelters. The occupiers believed they were being attacked by an entire assault group. In reality, they were being torn apart by robots from the 3rd Assault Corps.

"Yes, the UGVs carry out three tasks at once: they strike, they exert psychological pressure, and they clear the position. And most importantly, this happens without risk to our infantry," the force says.

The Bullspike grenade launchers were developed based on the Soviet RPG-22 anti-tank grenade launcher, which was previously manufactured under license by a Bulgarian defense company.

According to data from the manufacturer's website, the Bullspike RPG has a maximum aimed firing range of 350 meters, a direct-fire range of 150 meters, and armor penetration of 400 mm, Militarnyi reports.

The total weight of the launch unit, together with the 72.5 mm PG-22 grenade, is 3.4 kg. The length of the launcher is 780 mm.

The manufacturer states that the Bullspike-AT round is designed to destroy tanks, self-propelled artillery, and other armored vehicles, as well as to target enemy personnel located in bunkers, field fortifications, and urban-type brick fortifications.

The robots were controlled by operators from a safe shelter dozens of kilometers from the line of contact.

Earlier, for the first time in the world's history, the 3rd Army Corps dropped ground robots behind Russian lines from the air. The soldiers behind the mission say their heavy drones delivered kamikaze unmanned ground vehicles more than 10 kilometers into the Russian rear during the "second season" of Operation Vivaldi, letting Ukrainian troops flank them and clear another 40 square kilometers.

The Institute for the Study of War (ISW) published a map in its analytical report on 24 September that contrasts the claimed Russian encirclement with the location of Russian forces as assessed by the experts. Based on the evidence observed by ISW, the nearest area where Russian forces are present is 10.2 kilometers from the southeastern outskirts of Dobropillia.

Russia has been spreading disinformation about its successes around Dobropillia as part of what ISW calls a cognitive warfare effort to portray Ukrainian defenses as on the verge of collapse. Russia's Defense Ministry published a map claiming the city was surrounded. ISW's own map challenges it. The Ukrainian military says the city remains under its control.

Russian Defense Ministry claims it is already destroying encircled Ukrainian troops in Dobropillia and moving further

Units of Russia's Center Grouping of Forces continue combat operations against encircled Ukrainian forces in the Dobropillia area of Donetsk Oblast while simultaneously advancing toward Oleksandrivka, the Russian Defense Ministry claimed. ISW analysts, meanwhile, said they have not observed evidence supporting Russia's claim that the city is encircled. They also noted that Ukrainian officials "directly refute" the claim.

ISW observed evidence that Russian infiltrators, small groups, were operating east and northeast of Dobropillia on 19 and 20 September. The institute did not assess that these infiltrators had consolidated their positions.

Ukrainian forces maintain positions south and northeast of Dobropillia, military observer Kostiantyn Mashovets said on 20 September, according to ISW.

Russian forces have not made major gains in the Dobropillia direction, the chief of staff of an artillery reconnaissance battalion said on 22 September, according to the institute. On the same day, a Russian milblogger described the "alleged Russian encirclement of Dobropillia" as potentially meaning not the direct presence of infantry, but only the establishment of fire control over Ukrainian logistics, including roads west of Dobropillia and toward Sviatohorivka, according to ISW.

ISW noted that Russia's pervasive military culture of lying—what Russian milbloggers themselves call "beautiful reports"—has degraded the Defense Ministry's own ability to understand the battlefield and enabled inflated claims like the Dobropillia encirclement.

Russia uses this disinformation as a "diversion"

In its statement, the Russian Defense Ministry itself described Dobropillia as a "strongly fortified settlement" whose seizure would threaten key Ukrainian supply lines running from Dnipropetrovsk Oblast toward the Fortress Belt—the Sloviansk-Kramatorsk-Druzhkivka urban agglomeration.

Russia has recently renewed its attempts to break through toward Dobropillia.

Third Army Corps Commander Andrii Biletskyi said that Russian forces sought to bypass the fortified cities through Dobropillia and link up with troops advancing from north of Lyman, rather than launch a direct assault. ISW noted on 16 September that the Vivaldi operation disrupted Russia's two-pronged plan. In its 24 September report, ISW said Russia's claims about Dobropillia were partly intended to divert attention from Ukraine's elimination of the Russian salient north of Lyman, which has likely forced Russia's command to rethink its wider encirclement plans.

Ukraine's Third Army Corps says it became the first military unit in the world to use ground robots for mine clearance inside a live offensive, sending the machines ahead of its infantry into the deadliest sectors to keep soldiers out of the line of fire, Censor.NET reported. The corps built the capability from nothing during its Operation Vivaldi counteroffensive in Donetsk Oblast.

Keeping soldiers alive has become the organizing principle of how Ukraine fights, and handing the jobs most likely to kill them to ground robots is how an army that refuses to treat its people as expendable defends the line.

Robots cleared 30 km of routes in two nights

On the Shandryholove axis, the robots cleared 30 kilometers of routes in two nights—work that two companies of sappers would have needed a full week to finish. The corps reported no losses among its sappers there. Announcing the operation's second phase, corps commander Brigadier General Andrii Biletskyi said protecting personnel drives how his troops plan and fight:

"People often ask, but what about our losses? My answer: we minimize them by every possible means. In assault operations, drones and ground robots always move ahead of the infantry," he said.

Robots clear most of the mines and mine Russian routes in return

The corps says it built the system from scratch and scaled it from a single squad up to the entire corps, arguing that manual clearing would be impossible across open terrain swept by fire. Ground robots now lift roughly 60% of the anti-personnel mines in its area of responsibility. They also work in reverse, remotely mining Russian advance routes—one crew can lay up to 200 meters a day, cutting off enemy reserves. The same machines carry frontline logistics, evacuating the wounded and hauling in provisions and equipment.

Operation Vivaldi continues in Donetsk Oblast, where the corps recently air-dropped robots behind Russian lines. Its advance has disrupted Russia's plan to encircle the fortified belt of Donetsk cities. In the second phase, the Third Army Corps liberated Shandryholove and Derylove and took full control of Drobysheve. Across the operation's first two phases, it has retaken 125 square kilometers.