The Kalindan Defense System was a series of centrally controlled, unmanned defense network of planetary ion cannons and orbital ion mines. The system was controlled from a central base, and required a modular command circuit to function. The system was under the command of the Galactic Empire until the Kalindans revolted following the Battle of Endor. The technician in charge disabled the system and took the command module with him. Fortunately for the New Republic, the technician was picked up by a New Republic frigate disguised as an Imperial frigate and he surrendered it into their custody. Around 6 ABY, the New Republic arranged for the return of the command circuit in exchange for notes on cloaking device countermeasures that the Kalindan Royal Research Facility was developing.