"350"^^ . "6000"^^ . "Mark 21 Mod 2 torpedo"@en . . . "1946"^^ . . . "Gyroscope"@en . . . "22.5"^^ . "The Mark 21 Mod 2 torpedo, was a passive acoustic homing variant of the Mark 13 torpedo intended for use as a payload for the AUM-N-2 Petrel guided missile. Development of this torpedo was discontinued and it was not used in service to any extent."@en . "312"^^ . "The Mark 21 Mod 2 torpedo, was a passive acoustic homing variant of the Mark 13 torpedo intended for use as a payload for the AUM-N-2 Petrel guided missile. Development of this torpedo was discontinued and it was not used in service to any extent."@en . . . . "1943"^^ . "2130"^^ . "Aircraft"@en . . . . . "Mark 21 Mod 2 torpedo"@en . "161"^^ . "never in service"@en . . "Mark 8 contact exploder"@en . "Steam turbine"@en . "Mk 21, HBX-3"@en . . "33.5"^^ . "yes"@en . "Ordnance Research Laboratory, Pennsylvania State University"@en . "yes"@en . "Underwater Sound Laboratory, Harvard University"@en . "yes"@en .