HORNET Mines are a type of UNSC ordnance commonly carried aboard UNSC prowlers. They are stealthy, plutonium-cored, nuclear devices with a nominal yield of 30 megatons. During the Battle of Onyx, the UNSC Dusk laid a field of HORNETs, destroying twelve and damaging four Covenant warships. This prolonged the survival of Battlegroup Stalingrad, which was facing an overwhelming number of Covenant ships at the time. The severe reduction in the number of Covenant ships allowed the UNSC fleet to score a brief victory, before Covenant reinforcements arrived and destroyed the surviving human ships.