The Harpoon is an all-weather, over-the-horizon, anti-ship missile, developed and manufactured by McDonnell Douglas (now Boeing Defense, Space & Security). The Standoff Land Attack Missile (SLAM) is a land-attack variant.
The regular Harpoon uses active radar homing and flies just above the water to evade defenses. The missile can be launched from:
- Fixed-wing aircraft (the AGM-84, without the solid-fuel rocket booster)
- Surface ships (the RGM-84, fitted with a solid-fuel rocket booster that detaches when expended, to allow the missile’s main turbojet to maintain flight)
- Submarines (the UGM-84, fitted with a solid-fuel rocket booster and encapsulated in a container to enable submerged launch through a torpedo tube);
- Coastal defense batteries, from which it would be fired with a solid-fuel rocket booster.
In 1965 the United States Navy began studies for a missile in the 45 kilometres (24 nmi) range class for use against surfaced submarines. The name Harpoon was assigned to the project. The sinking of the Israeli destroyer Eilat in 1967 by a Soviet-built Styx anti-ship missile shocked senior United States Navy officers, who until then had not been conscious of the threat posed by anti-ship missiles. In 1970 Chief of Naval Operations Admiral Elmo Zumwalt accelerated the development of Harpoon as part of his “Project Sixty” initiative, hoping to add much-needed striking power to U.S. surface warships such as theTiconderoga-class cruiser.
The first Harpoon was delivered in 1977; in 2004, Boeing delivered the 7,000th.
The Harpoon has also been adapted for carriage on several aircraft, including the P-3 Orion, the P-8 Poseidon, the AV-8B Harrier II, the F/A-18 Hornet and the U.S. Air Force B-52H bombers. The Harpoon was purchased by many American allies, including India, Japan, Singapore, South Korea, Taiwan, the United Arab Emirates and most NATO countries.
The Royal Australian Air Force can fire AGM-84-series missiles from its F/A-18F Super Hornets, F/A-18A/B Hornets, and AP-3C Orion aircraft, and previously from the now retired F-111C/Gs. The Royal Australian Navy deploys the Harpoon on major surface combatants and in the Collins-class submarines. The Spanish Air Force and the Chilean Navy are also AGM-84D customers, and they deploy the missiles on surface ships, and F/A-18s, F-16s, and P-3 Orion aircraft. The British Royal Navy deploys the Harpoon on several types of surface ships.
The Royal Canadian Navy carries Harpoon missiles on its Halifax-class frigates. The Royal New Zealand Air Force is looking at adding the capability of carrying a stand-off missile, probably Harpoon or AGM-65 Maverick, on its six P-3 Orion patrol planes once they have all been upgraded to P3K2 standard.
The Republic of Singapore Air Force also operates five modified Fokker 50 Maritime Patrol Aircraft (MPA) which are fitted with the sensors needed to fire the Harpoon missile. The Pakistani Navy carries the Harpoon missile on its frigates and P-3C Orions. The Turkish Navy carries Harpoons on surface warships and Type 209 submarines. The Turkish Air Force will be armed with the SLAM-ER.
At least 339 Harpoon missiles were sold to the Republic of China Air Force (Taiwan) for its F-16 A/B Block 20 fleet and the Taiwanese Navy, which operates four guided-missile destroyers and eight guided-missile frigates with the capability of carrying the Harpoon, including the eight former U.S. Navy Knox-class frigates and the four former USN Kidd-class destroyers which have been sold to Taiwan. The two Zwaardvis/Hai Lung submarines and 12 P-3C Orion aircraft can also use the missile. The eight Cheng Kung-class frigates, despite being based on the US Oliver Hazard Perry class, have Harpoon capabilities deleted from their combat systems, and funding to restore it has so far been denied, the Republic of China Navy (Taiwan) decided to switch to the Hsiung Feng II and Hsiung Feng III.
The Block 1 missiles were designated AGM/RGM/UGM-84A in US service and UGM-84B in the UK. Block 1B standard missiles were designated AGM/RGM/UGM-84C, Block 1C missiles were designated AGM/RGM/UGM-84D. Block 1 used a terminal attack mode that included a pop-up to approximately 1,800 metres (5,900 ft) before diving on the target; Block 1B omitted the terminal pop-up; and Block 1C provided a selectable terminal attack mode.
Harpoon Block 1D
This version featured a larger fuel tank and re-attack capability, but was not produced in large numbers because its intended mission (warfare with the Warsaw Pact countries of Eastern Europe) was considered to be unlikely following the Dissolution of the Soviet Union. Range is 278 kilometres (173 mi) Block 1D missiles were designated RGM/AGM-84F.
SLAM ATA (Block 1G)
This version, under development, gives the SLAM a re-attack capability, as well as an image comparison capability similar to the Tomahawk cruise missile; that is, the weapon can compare the target scene in front of it with an image stored in its on-board computer during terminal phase target acquisition and lock on (this is known as DSMAC). Block 1G missiles AGM/RGM/UGM-84G; the original SLAM-ER missiles were designated AGM-84H (2000-2002) and later ones the AGM-84K (2002 onwards).
Harpoon Block 1J
Block 1J was a proposal for a further upgrade, AGM/RGM/UGM-84J Harpoon (or Harpoon 2000), for use against both ship and land targets.
Harpoon Block II
In production at Boeing facilities in Saint Charles, Missouri, is the Harpoon Block II, intended to offer an expanded engagement envelope, enhanced resistance to electronic countermeasures and improved targeting. Specifically, the Harpoon was initially designed as an open-ocean weapon. The Block II missiles continue progress begun with Block IE, and the Block II missile provides the Harpoon with a littoral-water anti-ship capability.
The key improvements of the Harpoon Block II are obtained by incorporating the inertial measurement unit from the Joint Direct Attack Munition program, and the software, computer, Global Positioning System (GPS)/inertial navigation system and GPS antenna/receiver from the SLAM Expanded Response (SLAM-ER), an upgrade to the SLAM.
The US Navy awarded a $120 million contract to Boeing in July 2011 for the production of about 60 Block II Harpoon missiles, including missiles for 6 foreign militaries. Boeing lists 30 foreign navies as Block II customers.
India acquired 24 Harpoon Block II missiles to arm its maritime strike Jaguar fighters in a deal worth $170 million through the Foreign Military Sales system. In December 2010, the Defense Security Cooperation Agency (DSCA) notified U.S. Congress of a possible sale of 21 additional AGM-84L HARPOON Block II Missiles and associated equipment, parts and logistical support for a complete package worth approximately $200 million; the Indian government intends to use these missiles on its Indian Navy P-8I Neptune maritime patrol aircraft. The Indian Navy is also planning to upgrade the fleet of four submarines – Shishumar class – with tube-launched Harpoon missiles.
Harpoon Block 2 missiles are designated AGM/RGM/UGM-84L.
In early 2018, the U.S. State Department approved the sale of Harpoon Block II to the Mexican Navy for use on their future Sigma-class design frigates, the first of which is being built by Damen Schelde Naval Shipbuilding.
Harpoon Block II+
On 18 November 2015, the U.S. Navy tested the AGM-84N Harpoon Block II+ missile against a moving ship target. The Block II+ incorporates an improved GPS guidance kit and a net-enabled data-link that allows the missile to receive in-flight targeting updates. The Block II+ is planned to enter service in 2017.
The USN intends to deploy the Harpoon Block II+ in late FY2018 by upgrading its existing inventory of Harpoon IC missiles.
Harpoon Block III
Harpoon Block III was intended to be an upgrade package to the existing USN Block 1C missiles and Command Launch Systems (CLS) for guided missile cruisers, guided missile destroyers, and the F/A-18E/F Super Hornet fighter aircraft. After experiencing an increase in the scope of required government ship integration, test and evaluation, and a delay in development of a data-link, the Harpoon Block III program was canceled by the U.S. Navy in April 2009.
Harpoon Block II+ ER
In April 2015, Boeing unveiled a modified version of the RGM-84 it called the Harpoon Next Generation. It increases the ship-launched Harpoon missile’s range from the Block II’s 70 nmi (81 mi; 130 km) to 167.5 nmi (192.8 mi; 310.2 km), along with a new lighter 300 lb (140 kg) warhead and a more fuel-efficient engine with electronic fuel controls. Boeing offered the missile as the U.S. Navy’s Littoral Combat Ship frigate upgrade over-the-horizon anti-ship missile as a cost-effective missile upgrade option; complete Next Gen Harpoons would cost approximately as much as a Block II at $1.2 million each, with upgrades for an existing missile costing half that. The version is also called the Harpoon Block II + ER. Boeing claims the Block II+ ER is superior to the Naval Strike Missile through its improved turbojet giving it greater range and active radar-homing seeker for all-weather operation, as well as a lighter but “more lethal” warhead. Test shots in 2017 had been confirmed. In May 2017, Boeing revealed it was no longer offering the upgraded Harpoon for the frigate OTH missile requirement, but would continue development of it.
|Mass||1,523 lb (691 kg) with booster|
|Length||Air-launched: 12.6 ft (3.8 m); Surface- and submarine-launched: 15 ft (4.6 m)|
|Diameter||13.5 in (34 cm)|
|Warhead||488 pounds (221 kg)|
|Engine||Teledyne CAE J402 Turbojet/solid propellant booster for surface and submarine launch; greater than 600 pounds (greater than 272.2 kg) of thrust|
|Wingspan||3 ft (0.91 m)|
|in excess of 150 nmi (280 km) depending on launch platform|
|Maximum speed||537 mph (864 km/h; 240 m/s; Mach 0.71)|
|Sea-skimming cruise monitored by radar altimeter / active radar terminal homing|