AGM-84 HarpoonAGM 84 Harpoon missile model. The Harpoon is an all weather, over the horizon, anti ship missile, developed and manufactured by McDonnell Douglas. The AGM 84E Standoff Land Attack Missile is a land attack variant. The Harpoon Missile is the preferred stand off land attack missile (SLAM) in the US Arsenal., They have a range of over 67 miles and a speed of 537 mph. It was originally designed to destroy naval ships of the enemy's fleet without having to