AGM/RGM/UGM-84 Harpoon

CG Ticonderoga class

DDG-51 Arleigh Burke class

SSN-688 Los Angeles class

FFG-7 Oliver Hazard Perry class

F-18 Hornet

F-14 Tomcat

B-52 /H Stratofortress

The Harpoon is the only dedicated anti-ship missile in service with U.S. armed forces. It has been developed into several advanced versions, including the SLAM (Stand-off Land Attack Missile) derivatives for high-precision attacks on land targets. The Harpoon and SLAM will remain in service with the U.S. Navy for the foreseeable future.

The Harpoon missile provides the Navy and the Air Force with a common missile for air, ship, and submarine launches. The weapon system uses mid-course guidance with a radar seeker to attack surface ships. Its low-level, sea-skimming cruise trajectory, active radar guidance and warhead design assure high survivability and effectiveness. The Harpoon missile and its launch control equipment provide the warfighter capability to interdict ships at ranges well beyond those of other aircraft.

The Harpoon missile was designed to sink warships in an open-ocean environment. Other weapons (such as the Standard and Tomahawk missiles) can be used against ships, but Harpoon and Penguin are the only missiles used by the United States military with anti-ship warfare as the primary mission. Once targeting information is obtained and sent to the Harpoon missile, it is fired. Once fired, the missile flys to the target location, turns on its seeker, locates the target and strikes it without further action from the firing platform. This allows the firing platform to engage other threats instead of concentrating on one at a time.

An appropriately configured HARPOON can be launched from an AERO-65 bomb rack, AERO-7/A bomb rack, MK 6 canister, MK 7 shock resistant canister, MK 12 thickwall canister, MK 112 ASROC launcher, MK 8 and MK 116 TARTAR launcher, or submarine torpedo tube launcher.

Submarines fire a capsule containing the Harpoon from their torpedo tubes. When the capsule breaches the surface, the top is blown off and the missile is launched. Aircraft launched Harpoons do not require a Booster. Depending upon launch conditions, the Harpoon engine generally will not start until after the missile is dropped from the wing. This allows firing from higher altitudes and longer range flights. The Guidance Section consists of an active radar seeker and radome, Missile Guidance Unit (MGU), radar altimeter and antennas, and power converter. The MGU consists of a three-axis attitude reference assembly (ARA) and a digital computer/power supply (DC/PS). Prior to launch, the DC/PS is initialized with data by the Command Launch System. After launch, the DC/PS uses the missile acceleration data from the ARA and altitude data from the radar altimeter to maintain the missile on the programmed flight profile. After seeker target acquisition, the DC/PS uses seeker data to guide the missile to the target.

The Warhead Section consists of a target-penetrating, load-carrying steel structure containing 215 pounds of high explosive (DESTEX) and a safe-and-arm/contact fuze assembly. The safe-and-arm/contact fuze assembly ensures the warhead will not explode until after the missile is launched. It is designed to explode the warhead after impacting the target. The warhead section can be replaced by an exercise section which transmits missile performance data for collection and analysis.

The Sustainer Section consists of a fuel tank with JP-10 fuel, air inlet duct, and a jet engine. This provides the thrust to power the missile during sustained flight. The Sustainer Section has four fixed fins which provide lift.

The Control Section consists of four electromechanical actuators which use signals from the Guidance Section to turn four fins which control missile motion.

The Booster Section consists of a solid fuel rocket and arming and firing device. Surface and submarine platforms use a booster to launch Harpoon and propel it to a speed at which sustained flight can be achieved. The Booster Section separates from the missile before sustained flight begins.

The Harpoon missile is powered by a Teledyne/CAE J402 turbojet in an A/B44G-1 propulsion section, giving it a maximum range of about 185 km (100 nm) for the air-launched version. For surface launches, RGM/UGM-84 variants use a solid-fueled rocket booster in an A/B44G-2 or -3 booster section, which is discarded after burn-out. Maximum range for surface launches is around 140 km (75 nm). After launch, the missile is guided towards the target location as determined by the launching aircraft or ship by a three-axis Attitude Reference Assembly (ATA) in an AN/DSQ-44 guidance section. The ATA is less accurate than a full-fledged inertial system, but good enough for Harpoon's range. For stabilization and control, the AGM-84A has four fixed cruciform wings (3x BSU-42/B, 1x BSU-43/B) and four movable BSU-44/B tailfins. The missile flies at a low cruise altitude, and at a predetermined distance from the expected target position, its AN/DSQ-28 J-band active radar seeker in the nose is activated to acquire and lock on the target. The radar switch-on distance can be set to lower or higher values, the former requiring a more precisely known target location but reducing the risk to be fooled by enemy ECM. An alternative launch mode is called BOL (Bearing-Only Launch). In this mode, the missile is launched in the general direction of the target, and its radar activated from the beginning to scan for the target in a +/- 45° sector in front of the flight path. Once a target has been located and the seeker locked, the xGM-84A missile climbs rapidly to about 1800 m before diving on the target ("pop-up manoeuver"). The 221 kg (488 lb) WDU-18/B penetrating blast-fragmentation warhead (in the WAU-3(V)/B warhead section) is triggered by a time-delayed impact fuze. When no target can be acquired after radar activation, the Harpoon will self-destruct.

The RGM-84A is usually fired from MK 140 (light weight) or MK 141 (shock-hardened) canister launchers, which hold four missiles, but older MK 112 (ASROC) or MK 26 (Standard) launchers can also be used. The RGM-84A has folding wings and fins which flip out immediately after exit from the launcher. For target acquisition and tracking, Harpoon-equipped surface ships use the AN/SWG-1 Harpoon Fire Control System.

The AGM-84D Harpoon is an all-weather, over-the-horizon, anti-ship missile system produced by Boeing [formerly McDonnell Douglas]. The Harpoon's active radar guidance, warhead design, and low-level, sea-skimming cruise trajectory assure high survivability and effectiveness. The missile is capable of being launched from surface ships, submarines, or (without the booster) from aircraft. The AGM-84D was first introduced in 1977, and in 1979 an air-launched version was deployed on the Navy's P-3 Orion aircraft. Originally developed for the Navy to serve as its basic anti-ship missile for fleetwide use, the AGM-84D also has been adapted for use on the Air Force's B-52G bombers, which can carry from eight to 12 of the missiles.

The AGM-84D Harpoon Block 1D (with a larger fuel tank and reattack capability) was developed in 1991. With the reduced threat because of the break-up of the Soviet Union, this upgrade was shelved and never produced.

The AGM-84E Harpoon/SLAM [Stand-Off Land Attack Missile] Block 1E is an intermediate range weapon system designed to provide day, night and adverse weather precision strike capability against high value land targets and ships in port. In the late 1980s, a land-attack missile was needed. Rather than design one from scratch, the US Navy took everything from Harpoon except the guidance and seeker sections, added a Global Positioning System receiver, a Walleye optical guidance system, and a Maverick data-link to create the Stand-off Land Attack Missile (SLAM). The AGM-84E uses an inertial navigation system with GPS, infrared terminal guidance, and is fitted with a Tomahawk warhead for better penetration. SLAM can be launched from land-based or aircraft carrier-based F/A-18 Hornet aircraft. It was employed successfully in Operation Desert Storm and UN relief operations in Bosnia prior to Operation Joint Endeavor.

The SLAM-ER (Expanded Response) Block 1F, a major upgrade to the SLAM missile that is currently in production, provides over twice the missile range, target penetration capability, and control range of SLAM. SLAM-ER has a greater range (150+ miles), a titanium warhead for increased penetration, and software improvements which allow the pilot to retarget the impact point of the missile during the terminal phase of attack (about the last five miles). In addition, many expansions were made to improve performance, survivability, mission planning, and pilot (man-in-the-loop) interface. SLAM ER's man-in-the-loop control system offers several tactically significant advantages over other types of standoff weapon guidance systems. Viewing the target in real time prior to impact allows target identification, reduces collateral damage, provides an immediate indication of mission success, and permits the pilot to select an alternate aimpoint if desired. SLAM ER combines man-in-the-loop control with a highly precise inertial navigation system, jam resistant GPS, and a hardened data link. In combination, these features negate the usual inherent errors associated with ship motion, target location, and GPS navigational accuracy. The SLAM-ER development contract was awarded to McDonnell Douglas Aerospace (Now BOEING) in February of 1995. SLAM-ER achieved its first flight in March of 1997. All Navy SLAM missiles are currently planned to be retrofitted to SLAM-ER configuration. About 500 SLAM missiles were converted to the SLAM-ER configuration between FY 1997 and FY 2001. The Navy plans to upgrade its entire inventory of 700 SLAMs into the SLAM ER configuration. In mid-2001 the Naval Air Systems Command (NAVAIR) entered into sole source negotiations and subsequently award a contract to McDonnell Douglas Corp. (MDC), a Wholly Owned Subsidiary of the Boeing Company for the integration and test and evaluation of a Global Positioning System (GPS) receiver equipped with a Selective Availability Anti-Spoofing Module (SAASM) for the Stand-off Land Attack Missile-Expanded Response (SLAM-ER) weapon system. The purpose of this effort is to comply with current Department of Defense GPS security requirements for those weapon systems that contain GPS components.

The SLAM-ATA (Automatic Target Acquisition) Block 1G, a follow on enhancement to SLAM-ER with reattack capability and new seeker, is under development. SLAM-ERs equipped with ATA will match the seeker images of a target scene with an on-board reference image. This process will improve the missile's ability to strike targets in cluttered spaces, such as urban areas. It will also improve missile targeting capability in poor weather, counter measure protected environments, and better enable offset aimpoint targeting.

The Harpoon Block II is an upgrade program to improve the baseline capabilities to attack targets in congested littoral environments. The upgrade is based on the current Harpoon. Harpoon Block II will provide accurate long-range guidance for coastal, littoral and blue water ship targets by incorporating the low cost integrated Global Positioning System/Inertial Navigation System (GPS/INS) from the Joint Direct Attack Munitions (JDAM) program currently under development by Boeing. GPS antennae and software from Boeing's Standoff Land Attack Missile (SLAM) and SLAM Expanded Response (SLAM ER) will be integrated into the guidance section. The improved littoral capabilities will enable Harpoon Block II to impact a designated GPS target point. The existing 500 pound blast warhead will deliver lethal firepower against targets which include coastal anti-surface missile sites and ships in port. For the anti-ship mission, the GPS/INS provides improved missile guidance to the target area. The accurate navigation solution allows target ship discrimination from a nearby land mass using shoreline data provided by the launch platform. These Block II improvements will maintain Harpoon's high hit probability while offering a 90% improvement in the separation distance between the hostile threat and local shorelines. Harpoon Block II will be capable of deployment from all platforms which currently have the Harpoon Missile system by using existing command and launch equipment. A growth path is envisioned for integration with the Vertical Launch System and modern integrated weapon control systems. With initiation of engineering and manufacturing development in 1998, initial operational capability for Block II will be available by 2001.

At the direction of Headquarters Strategic Air Command, the Harpoon Air Command and Launch Control Set was fully integrated into a fully operational B-52G from Mather AFB, Calif., in March 1983. Three successful live launches at the Naval Air Warfare Center, Point Mugu, Calif., led to the modification of a total of 30 B-52Gs with Harpoon launch control equipment, enough to provide two squadrons of Harpoon-capable B-52Gs by June 30, 1985. The 42nd Bombardment Wing, Loring Air Force Base, Maine, and the 43rd Bombardment Wing, Andersen Air Force Base, Guam, were first tasked to perform the Harpoon mission. Both wings refined tactics and doctrine to merge the long-range, heavy-payload capability of the B-52 with the proven reliability of this superior stand-off attack weapon.

After Loring AFB closed and the retirement of the last B-52G at Castle AFB, Calif., the Harpoon mission was moved to the 2nd Bomb Wing at Barksdale AFB, La. Four B-52H models were rapidly modified (as an interim measure) to accept Harpoon launch control equipment pending B-52H fleet modification. By 1997, all B-52H airframes were Harpoon capable, providing both the 5th Bomb Wing at Minot AFB, N.D., and the 2nd Bomb Wing at Barksdale, full squadron strength capability.

The AGM-84K is an upgraded variant of the AGM-84H SLAM-ER with internal improvements. Developmental tests of the hardware and software updates of the AGM-84K were conducted in early 2001, followed by operational test and evaluation in the first half of 2002, and Initial Operational Capability in July 2002. Existing AGM-84Hs will be upgraded to AGM-84K standard. Training versions are the ATM-84K and CATM-84K.

The latest upgrade of the AGM-84H/K SLAM-ER is the SLAM-ER ATA (Automatic Target Acquisition). This missile can be launched in the general direction of the target and will automatically select a target by comparing the stored reference image with the IIR seeker image without the need for operator intervention. However, the operator can take over control of the missile at any time in the mission, thereby retaining the capabilities of the basic SLAM-ER. The ATA system was released to the Fleet in 2002, and existing AGM-84H/K missiles will eventually be upgraded.

Although the GPS-equipped Harpoon Block 2 was not ordered by the U.S. Navy, the missile was offered for export, and eventually ordered by several contries, including Egypt, the United Arab Emirates, Taiwan, and South Korea. These export missiles are designated RGM-84L. Korea has also ordered the air-launched AGM-84L variant.

More than 7000 Harpoon anti-ship missiles (including production for foreign countries) and 1000 SLAM variants have been built so far. Production of the anti-ship missiles continues for non-US customers, while productuon for the U.S. Navy will continue with the AGM-84K SLAM-ER ATA. Current U.S. platforms for the AGM-84 anti-ship Harpoon are the Navy's F/A-18, P-3C and S-3B and also a few B-52Hs of the USAF. The AGM-84E/H/K SLAM is mainly employed by the F/A-18, but has been used by the P-3C.