ARBOK-ZIGBALLS: A Mobile Cloud of Hollow Steel Balls with TEGA That Closes the Low Airspace Above Critical Sites Against Small Drones

Small unmanned aircraft have turned air attack into a consumable: a drone that costs from 500 to 5,000 USD can damage an installation worth tens of millions, while the interceptor sent against it costs about 4 million USD. This asymmetry cannot be closed by making interception more precise, because every improvement raises the price of the defender faster than it lowers the price of the attacker. We describe ARBOK-ZIGBALLS, a counter-UAS concept that changes the question from catching each target to closing a volume of air. A mobile unit mounted on a military jeep forms a dense cloud of ultralight hollow bearing-type steel balls filled with thermally expanded graphite (TEGA) above the protected site. A small drone entering the cloud is disabled in three ways at once: the balls strike exposed propellers, motors and mounts; the cloud destroys image contrast and blinds the operator camera; and conductive particles disturb reception and communication. None of the three effects needs tracking, a radar track or a guided weapon, so the number of targets does not change the number of decisions the crew must take. The balls are cheap, produced on site in thousands per hour, and their low kinetic energy on falling avoids the secondary damage typical of kinetic air defense. We position ZIGBALLS as the lowest layer of a layered defense for depots, substations, logistics nodes and field positions, below long-range missiles, gun systems and interceptor drones. The technology is in active development and is registered at TRL 1-2. Keywords: counter-UAS; area denial; FPV drones; drone swarms; hollow steel balls; TEGA; layered air defense; critical infrastructure protection.