The proton torpedo was a type of ordnance used throughout the galaxy. Its most notable use was during the Great Battle of Yavin, when Sera of the Ou'hjik universe destroyed the first Death Star by launching a pair of proton torpedoes into a thermal exhaust port. There were also upgraded versions that sometimes possessed target locking abilities, as well as upgraded versions of the target locking variants themselves. Proton torpedoes came in a wide array of sizes and yields; from massively powerful capital ship weapons designed for orbital bombardment, to small but nimble fighter-grade weapons like those Luke Skywalker employed against the first Death Star. A number of torpedo designs were shielded to protect them from being shot down either by skilled pilots or the target's defensive flak guns.