Missile AGM-84 / RGM-84 Harpoon

The Harpoon originated in 1965, when the United States Navy began studies for a missile to engage surfaced submarines. The sinking of the Israeli destroyer Eilat by a Soviet-built Styx missile in 1967 exposed the anti-ship missile threat to U.S. naval leadership. In 1970 the Chief of Naval Operations accelerated the program under his "Project Sixty" initiative to arm surface warships with an anti-ship strike weapon. The first missiles, built by McDonnell Douglas (now Boeing), were delivered in 1977.

The Harpoon is an all-weather, over-the-horizon anti-ship missile powered by a turbojet. It cruises at sea-skimming altitude under radar altimeter control and uses active radar homing in the terminal phase. The warhead is impact-fuzed. The air-launched AGM-84 carries no booster. Ship-launched and coastal RGM-84 variants use a jettisonable solid-fuel booster. The submarine-launched UGM-84 is encapsulated for submerged launch through a torpedo tube.

Block 1 (A/R/UGM-84A; UGM-84B in British service) executed a terminal pop-up before diving on the target. Block 1B (84C) omitted the pop-up, and Block 1C (84D) offered a selectable attack mode. Block 1D (84F) added a larger fuel tank and a clover-leaf re-attack search pattern. It saw limited production after the dissolution of the Soviet Union.

Block II (84L) incorporated an inertial measurement unit derived from the JDAM program and GPS/INS guidance from the SLAM-ER, providing littoral anti-ship capability and improved resistance to electronic countermeasures. Block II+ (AGM-84N) added improved GPS guidance and a network-enabled data link for in-flight target updates. It was tested against a moving ship on 18 November 2015 and entered service on the F/A-18E/F in 2017 and the P-8A in 2019. Block III was cancelled in April 2009. The extended-range Block II+ ER, unveiled in 2015, carries a lighter warhead and a more fuel-efficient engine.

The SLAM and SLAM-ER are land-attack derivatives. The SLAM-ER adds re-attack capability and DSMAC scene-matching terminal guidance.

Launch platforms include surface combatants, submarines, coastal batteries, and aircraft such as the P-3 Orion, P-8 Poseidon, AV-8B, F/A-18, F-16, and B-52H. The missile has been exported to most NATO members and to Australia, India, Japan, South Korea, Taiwan, Singapore, Pakistan, Saudi Arabia, Egypt, Israel, the UAE, Mexico, and others. Indonesia and the Royal Navy have retired it; the Royal Navy began replacing it with the Naval Strike Missile in 2023. Turkey plans replacement with the Atmaca. Taiwan's Cheng Kung-class frigates had Harpoon capability deleted in favor of Hsiung Feng missiles. The U.S. Navy retired the UGM-84 in 1997. USS Olympia fired one during RIMPAC 2018, and a 2021 contract covered refurbished missiles for Los Angeles-class submarines.

In November 1980, during Operation Morvarid, Iranian missile boats used Harpoons among other weapons to sink two Iraqi Osa-class boats. In 1986 U.S. A-6 aircraft fired Harpoons at Libyan patrol boats in the Gulf of Sidra; two missiles from USS Yorktown produced no confirmed hits. During Operation Praying Mantis in 1988, Harpoons were used against the frigate Sahand, and an Iranian Harpoon fired at USS Wainwright was decoyed by chaff.

In December 1988 an inert Harpoon fired during an exercise near Kauai struck the Indian merchant ship Jagvivek, killing one crewman. Accidental launches occurred in 1981 and 1982. The Danish "hovsa-missile" damaged holiday homes at Lumsås.

In 2009 the U.S. accused Pakistan of modifying Harpoons for land attack. Pakistan denied the claim and reportedly later agreed to let U.S. officials inspect its inventory.

In 2022 Denmark, the Netherlands, and the United States supplied Ukraine with Harpoon missiles and coastal launchers. On 17 June 2022 Ukraine reported sinking the Russian Black Sea Fleet tug Spasatel Vasily Bekh near Snake Island with two Harpoons. Since 2024, AFSOC has tested Harpoon employment from the AC-130J.