A Russian radar installation during Vostok-2018 (East-2018) military drills at Telemba training ground on September 12, 2018.MLADEN ANTONOV/AFP via Getty ImagesUkraine said on Tuesday that it used 7 exploding drones to destroy a Russian radar system.Ukrainian media said the destroyed system was a Nebo-U, which monitors hundreds of miles of airspace.Ukraine assessed that the Nebo-U, downed by cheap drones, was worth $100 million.Ukrainian media reported on Tuesday that Kyiv destroyed a sophisticated Russian radar complex using seven exploding drones, in another apparent sign of how the cheap, unmanned devices are changing the face of modern combat.Citing an unnamed source from the Security Service of Ukraine (SBU), the Kyiv Independent and Ukrainska Pravda reported that the Russian system was a Nebo-U radar complex stationed in Bryansk, a Russian region bordering northern Ukraine.It was monitoring Ukrainian airspace as deep as 434 miles past the border, per the SBU source.