The AGM-84 Harpoon is a guided missile used by the United States Navy and Air Force as a common anti-ship weapon. Developed in the early 1970s, and produced by Boeing (formerly by McDonnell Douglas) as an all weather, over the horizon, fire and forget anti ship weapon. Although other weapons in the U.S. arsenal can be used in anti-ship roles, such as the Standard or the Tomahawk missiles, the Harpoon (along with the Penguin) is the only dedicated anti-ship missile system currently employed by the United States. The Harpoon was designed to be operated from a number of different platforms, increasing its flexibility. The Harpoon can be drop-launched from fighter and bomber aircraft, launched from ship-based missile launchers, from ground trucks, as well as fired by submerged submarines.

The submarine launch system is unique, in that it is different from the standard method of launching submarine missiles. In the standard method, the submarine launches a missile (such as the Trident, or the old Polaris or Neptune missiles) from vertical launch silos, where they pushed up to the surface. Upon hitting air, they would ignite their engines and launch. The Harpoon is different primarily in that it is launched from the sub's horizontal torpedo tubes, in a special casing that resembles a torpedo with a blunt nose. It is referred to as an ENCAP (for encapsulated). When the torpedo casing reaches the surface (it does this with no power, it simply floats upwards), it bursts open with a rocket charge, brings the Harpoon to a firing angle, and a special rocket booster powers the missile into the air. When the Harpoon is safely away from the water, its own engines will activate, carrying it to the target area.

The targeting system of the Harpoon does not depend on having a fixed target from launch to impact. Instead, the Harpoon's digital computer/power supply (dc/ps) is directed to fly the missile to the area of the target. When in flight, the missile uses its on-board radar altimeter, and attitude reference assembly (ARA) to follow the prescribed flight path. When the missile has arrived in the target area, the Missile Guidance Unit (MGU) begins to feed the dc/ps with data from the active radar seeker located at the forward tip of the missile. The active radar seeker searches out the precribed radar silhouette, and directs the missile to that location. If the Harpoon misses the target, and is still in flight, it is generally unable to reaquire its target (however, a planned upgrade to the Harpoon (AGM-84D Harpoon Block 1D) would have added a larger fuel supply and reattack capability, but was discontinued before production in 1991 due to the collapse of the Soviet Union.)

The Harpoon is powered by a jet engine. The original models introduced in 1977 and 1979 had a range of over 60 nautical miles, however the Stand-off Land Attack Missile (SLAM), was developed in the 1980s, with a number of improvements and modifications to the standard Harpoon design. The guidance and seeker section of the Harpoon was tossed out, and replaced with parts from other weapon systems. Added were a Global Positioning System receiver, a Walleye optical guidance system, and a Maverick data-link. Also, the warhead was replaced with that on a Tomahawk crusie missile, for better target penetration.

A development contract for the more advanced SLAM-ER (Expanded Response) Harpoon was awarded to McDonnel Douglas (now Boeing) in 1995. The SLAM-ER (pronounced 'slammer' by some) incorporates a new 'titanium-based' warhead for penetration in addition to that of the Tomahawk warhead. In addition to the general performance improvements the SLAM-ER also includes a number of software upgrades that allow human controllers and pilots to direct the missile in the last stages of its 'terminal' approach (the last five nautical miles before striking the target). The SLAM-ER first flew in 1997, and the United States Navy intends to have all of their current SLAM missiles upgraded, and approximately 500 were converted by the end of (fiscal year) 2001.

AGM-84 Harpoon
Primary Function: Air-to-surface anti-ship missile

  • Mission: Maritime ship attack
  • Targets: Maritime surface
  • Service: Navy and Air Force
  • Contractor: Boeing (ex McDonnell Douglas)
  • Power Plant: Teledyne Turbojet and solid propellant booster for surface and submarine launch
  • Program status: Operational
  • Development cost: $320.7 million
  • Production cost: $2,882.3 million
  • Total acquisition cost: $3,203.0 million
  • Acquisition unit cost: $527,416
  • Production unit cost: $474,609
  • Quantity Navy: 5,983; Air Force: 90

    Launch Platforms:

    Surface Vessels
  • Conventional/Nuclear Guided Missile Cruisers (CG/CGN)
  • Guided Missile Destroyers (DDG)
  • Destroyers (DD)
  • Guided Missile Frigates (FFG)
  • Frigates (FF)
  • Fast Attack Craft (FPB)
    Aircraft
  • P-3 Orion ASW Patrol
  • S-3 ASW Patrol
  • F/A-18 Hornet (Attack Fighter)
  • B-52 Stratofortress (Bomber)
  • F-16 Fighting Falcon (Fighter)
  • Nimrod
    Submarine
  • Los Angeles Class Sub(SSN)
  • Seawolf Class Nuclear Attack Submarine (SSN)
  • Virginia Class Nuclear Attack Submarine (SSN)
    Other
  • Costal Defense Batteries*

    *A Harpoon-equipped coastal defense battery would consist of two trucks, one with the missile, and another for firing and targeting control. The two trucks would be parked several miles off the coast (though they could be placed many miles inland, making detection and elimination of the battery difficult). They would be connected by a series of cables, and would wait for targeting information. With firing orders and targeting information, the battery could begin launching missiles at targeted ships off the coast (likely within the 60+ nautical mile firing radius, but perhaps also in the 150+ radius). These coastal batteries would effectively interdict an area of coast from large scale enemy landings, or hold a strait or other strategically important body of water.


    Statistics for four types of AGM-84 Harpoon


    Sea Launched Harpoon
  • First capability: 1977
  • Length: 15 feet (4.55 meters)
  • Weight: 1,470 pounds (661.5 kilograms)
  • Diameter: 13.5 inches (34.29 centimeters)
  • Wingspan: 3 feet (91.44 centimeters)
  • Thrust: 660 pounds
  • Range: Greater than 60 nautical miles
  • Speed: 855 km/h
  • Guidance System: Sea-skimming cruise with mid-course guidance monitored by radar altimeter, active seeker radar terminal homing
  • Warheads: Penetration high-explosive blast (488 pounds)
  • Explosive: Destex
  • Fuse: Contact


    Air Launched Harpoon
  • First capability: 1979
  • Length: 12 feet, 7 inches (3.79 meters)
  • Weight: 1,145 pounds (515.25 kilograms)
  • Diameter: 13.5 inches (34.29 centimeters)
  • Wingspan: 3 feet (91.44 centimeters)
  • Thrust: 660 pounds
  • Range: Greater than 60 nautical miles
  • Speed: 855 km/h
  • Guidance System: Sea-skimming cruise with mid-course guidance monitored by radar altimeter, active seeker radar terminal homing
  • Warheads: Penetration high-explosive blast (488 pounds)
  • Explosive: Destex
  • Fuse: Contact


    Stand-off Land Attack Missile (SLAM) Harpoon
  • Length: 14 feet, 8 inches (4.49 meters)
  • Weight: 1,385 pounds (629.55 kilograms)
  • Diameter: 13.5 inches (34.29 centimeters)
  • Wingspan: 3 feet (91.44 centimeters)
  • Thrust: 660 pounds
  • Range: Greater than 150 nautical miles
  • Speed: 855 km/h
  • Guidance System: inertial navigation system with GPS, infrared terminal guidance
  • Warheads: Penetration high explosive blast (488 pounds)
  • Explosive: Destex
  • Fuse: Contact


    Stand-off Land Attack Missile-Expanded Response (SLAM-ER) Harpoon
  • Length: 14 feet, 8 inches (4.49 meters)
  • Weight: 1,385 pounds (629.55 kilograms)
  • Diameter: 13.5 inches (34.29 centimeters)
  • Wingspan: 3 feet (91.44 centimeters)
  • Thrust: 660 pounds
  • Range: Greater than 150 nautical miles
  • Speed: 855 km/h
  • Guidance System: inertial navigation system with GPS, infrared terminal guidance
  • Warheads: Penetration high-explosive blast (488 pounds)
  • Explosive: Destex
  • Fuse: Contact

    Sources
    http://www.fas.org/man/dod-101/sys/smart/agm-84.htm
    http://www.boeing.com/defense-space/missiles/harpoon/flash.html
    http://www.chinfo.navy.mil/navpalib/factfile/missiles/wep-harp.html
    http://www.af.mil/news/factsheets/AGM_84D_Harpoon_Missile.html

    liveforever says re AGM-84 Harpoon: In Denmark, the Harpoon missile has become famous as the "Hovsa-missil" (the "Oops Missile") after an accidental launch destroyed a large area of summer cottages (no casualties) in the 1980s.