The M712 Copperhead is a

155 mm 155 mm (6.1 in) is a common, NATO-standard, artillery caliber. It is defined in AOP-29 part 1 with reference to STANAG 4425. It is commonly used in field guns, howitzers, and gun-howitzers. Land warfare The caliber originated in France aft ...

caliber In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matc ...

cannon-launched guided projectile Cannon-launched guided projectiles (CLGP) are precision-guided munitions launched by howitzers, mortars, tank guns, and naval guns. Those projectile main propulsion system is the initial kinetic shoot, directed as much as possible toward the target ...

. It is a fin-stabilized, terminally

laser guided Laser guidance directs a robotics system to a target position by means of a laser beam. The laser guidance of a robot is accomplished by projecting a laser light, image processing and communication to improve the accuracy of guidance. The key ide ...

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

intended to engage hard point targets such as

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and good battlefield mobility provided by tracks and a powerful ...

s, self-propelled

howitzer A howitzer () is a long- ranged weapon, falling between a cannon (also known as an artillery gun in the United States), which fires shells at flat trajectories, and a mortar, which fires at high angles of ascent and descent. Howitzers, like ot ...

s or other high-value targets. It may be fired from different

artillery piece Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, ...

s, such as the

M114 M114 or M-114 may refer to: * M114 155 mm howitzer, a towed howitzer used by the United States Army * M114 armored fighting vehicle, a Vietnam War-era tracked armored fighting vehicle, used by the United States Army * M114 bomb The M114 bomb was a ...

M109 The M109 is an American 155 mm turreted self-propelled howitzer, first introduced in the early 1960s to replace the M44. It has been upgraded a number of times, most recently to the M109A7. The M109 family is the most common Western indirect ...

M198 The M198 is a medium-sized, towed 155 mm artillery piece, developed for service with the United States Army and Marine Corps. It was commissioned to be a replacement for the World War II-era M114 155 mm howitzer. It was designed and prototyped a ...

M777 The M777 howitzer is a British towed 155 mm artillery piece in the howitzer class. It is used by the ground forces of Australia, Canada, Colombia, India, Saudi Arabia, Ukraine, and the United States. It was first used in combat during the US ...

and

CAESAR Gaius Julius Caesar (; ; 12 July 100 BC – 15 March 44 BC), was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in a civil war, an ...

howitzers. The projectile has a minimum range of 3 km and a maximum range of 16 km.

Development

The concept for Copperhead was originally made in 1970 by engineers at the US Army's Rodman Laboratories, with feasibility studies conducted in 1971. In 1972 development contracts were awarded to

Martin Marietta The Martin Marietta Corporation was an American company founded in 1961 through the merger of Glenn L. Martin Company and American-Marietta Corporation. In 1995, it merged with Lockheed Corporation to form Lockheed Martin. History Martin Mari ...

and

Texas Instruments Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...

. After testing Martin Marietta was chosen for continued development through the 1970s. Inventories of March 1, 1995: * US Army : Usable : 16,095 - Unusable 0 - Total : 16,095 * USMC : Usable : 1,873 - Unusable : 894 - Total : 2,767

Description

At and long, Copperhead is longer and heavier than traditional 155mm ammunition. The warhead assembly consists of a

shaped charge A shaped charge is an explosive charge shaped to form an explosively formed penetrator (EFP) to focus the effect of the explosive's energy. Different types of shaped charges are used for various purposes such as cutting and forming metal, ini ...

loaded with of

Composition B Composition B, colloquially Comp B, is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades and various other munitions. It was also use ...

. For Copperhead to function, the target must be illuminated with a

laser designator A laser designator is a laser light source which is used to designate a target. Laser designators provide targeting for laser-guided bombs, missiles, or precision artillery munitions, such as the Paveway series of bombs, AGM-114 Hellfire, o ...

. Once the laser signal is detected, the on-board

guidance system A guidance system is a virtual or physical device, or a group of devices implementing a controlling the movement of a ship, aircraft, missile, rocket, satellite, or any other moving object. Guidance is the process of calculating the changes in po ...

will operate the steering vanes to maneuver the projectile to the target. The Copperhead targeting

logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from prem ...

is designed to ensure (1) that the optical system will always be able to detect the target, and (2) that once the target has been detected there will be sufficient time and

velocity Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity i ...

to maneuver to hit the target. Copperhead must be below any cloud cover at critical parts of the trajectory, and there must be sufficient visibility to ensure that when the target is acquired the projectile will have sufficient time to maneuver.

Modes of operation

Copperhead CLGP axial section with description

Copperhead has two modes of operation: ballistic mode and glide mode. Ballistic mode is used where the cloud ceiling is high and visibility is good. When the projectile is 3,000 meters from the target, the guidance vanes extend, the target is acquired, and then the on-board guidance system adjusts the guidance vanes to maneuver onto the target. Glide mode is used when the

cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...

ceiling and/or the

visibility The visibility is the measure of the distance at which an object or light can be clearly discerned. In meteorology it depends on the transparency of the surrounding air and as such, it is unchanging no matter the ambient light level or time o ...

is too low to permit the use of the ballistic mode. A glide mode

trajectory A trajectory or flight path is the path that an object with mass in motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates; hence, a complete tr ...

consists of two phases: a ballistic phase and a glide phase. At a predetermined point along the trajectory, the guidance vanes extend and there is a transition from ballistic phase to glide phase. Glide phase targeting logic is designed to ensure the largest possible angle of fall permitted by the

cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud c ...

and the visibility. The target is acquired when the projectile is close enough to detect the laser illumination or when the projectile emerges from the cloud cover, whichever event occurs later in the trajectory. When a trajectory solution has been obtained, time-to-target and

terminal velocity Terminal velocity is the maximum velocity (speed) attainable by an object as it falls through a fluid ( air is the most common example). It occurs when the sum of the drag force (''Fd'') and the buoyancy is equal to the downward force of grav ...

are checked to ensure that there will be enough time to maneuver and that the projectile is

aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...

ally stable—that it will not stall while maneuvering. Initially the laser designation was intended to be performed by the MQM-105 Aquila pilotless drone.

Combat history

Copperhead was used in

Operation Desert Storm Operation or Operations may refer to: Arts, entertainment and media * ''Operation'' (game), a battery-operated board game that challenges dexterity * Operation (music), a term used in musical set theory * ''Operations'' (magazine), Multi-Ma ...

, with 90 rounds fired against hardened Iraqi fortifications and radar stations. One of these strikes caused an Iraqi unit to surrender. Lebanese Armed Forces fired several hundred Copperhead shells at

ISIL An Islamic state is a state that has a form of government based on Islamic law (sharia). As a term, it has been used to describe various historical polities and theories of governance in the Islamic world. As a translation of the Arabic term ...

targets in east

Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus lie ...

during the

Qalamoun offensive (July–August 2017) The Qalamoun offensive (2017) was a military operation launched by Hezbollah, the Syrian Armed Forces, and later the Lebanese Armed Forces, against members of Tahrir al-Sham and the Islamic State of Iraq and the Levant on the Lebanon–Syria bor ...

. At least five

technicals Technicals may refer to: * Technical (vehicle), an improvised fighting vehicle often used in civil conflict * TECHNICALS, a clothing brand owned by Blacks Leisure Group See also * Technical (disambiguation) * Cambridge Technicals Cambridge Tech ...

, five occupied buildings, and several troop formations were struck with precision. The US replenished 827 shells after the successful completion of the offensive.

Operators

Current operators

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...

Jordan Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the no ...

Former operators

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

– now replaced by

SMArt 155 SMArt 155 is a German 155 mm artillery round, designed for a long range, indirect fire top attack role against armoured vehicles. The SMArt carrier shell contains two submunitions with infrared sensor and millimeter wave radar, which des ...

References

Sources

* Yenne, William, Yenne, Bill, ''Attack of the Drones: A History of Unmanned Aerial Combat'', Zenith Imprint, 2004 {{ISBN, 0-7603-1825-5 155mm artillery shells Anti-tank rounds Guided artillery shells Military equipment introduced in the 1980s