The Extended Range Guided Munition was a

precision guided A precision-guided munition (PGM), also called a smart weapon, smart munition, or smart bomb, is a type of weapon system that integrates advanced guidance and control systems, such as GPS, laser guidance, or infrared sensors, with various type ...

rocket A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

-assisted 5-inch (127 mm)

shell (projectile) A shell, in a modern military context, is a projectile whose payload contains an explosive, incendiary device, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military ...

development by

Raytheon Raytheon is a business unit of RTX Corporation and is a major U.S. defense contractor and industrial corporation with manufacturing concentrations in weapons and military and commercial electronics. Founded in 1922, it merged in 2020 with Unite ...

for the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Department of Defense. It is the world's most powerful navy with the largest displacement, at 4.5 million tons in 2021. It has the world's largest aircraft ...

. The program was cancelled in March 2008 after twelve years of development and over 600 million dollars in funding. The developmental round was designated EX 171.Raytheon ERGM (5" Projectile MK 171) - Designation Systems
/ref> ERGM consisted of three major subsections: propulsion (rocket motor), warhead, and Guidance, Navigation and Control section. ERGM is fired from the 127 mm (5-inch) 62-caliber Mark 45 gun Mod 4, at which point the fins would deploy and the rocket motor would ignite, lifting the munition to at least , after which the canards would deploy and guide the ERGM to the target using

GPS The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide geol ...

guidance. It was to be used on s hulls DDG-81 onward. A similar system (though for

MLRS A multiple rocket launcher (MRL) or multiple launch rocket system (MLRS) is a type of rocket artillery system that contains multiple launchers which are fixed to a single platform, and shoots its rocket ordnance in a fashion similar to a vol ...

) developed by

SAAB Saab or SAAB may refer to: Brands and enterprises * Saab AB, a Swedish aircraft, aerospace and defence company, still known as SAAB, and together with subsidiaries as Saab Group ** Datasaab, a former computer company, started as spin off from Saab ...

and

Boeing The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support s ...

reached production in 2019 and is known as the

GLSDB The Ground Launched Small Diameter Bomb (GLSDB) is a weapon developed by Boeing and the Saab Group to allow Boeing's GBU-39 Small Diameter Bomb (SDB), originally developed for use by aircraft, to be ground-launched from a variety of launchers an ...

Synopsis

Despite the long development time, the ERGM never worked as reliably as the older but significantly less expensive laser-guided

M712 Copperhead The M712 Copperhead is a 155 mm caliber cannon-launched guided projectile. It is a fin-stabilized, terminally laser guided, explosive shell intended to engage hard point targets such as tanks, self-propelled howitzers or other high-value tar ...

. During development, the ERGM failed several tests in which the tail fins failed to deploy at launch, rocket motors did not ignite, or the electronic components did not survive the stress of being fired from a gun.Guided munition may be canceled - Navy Times
/ref> In February 2008, guidance components, rocket motors, and tail fins all failed in tests; Raytheon claimed they were testing specific functionalities rather than overall functionality and that they were "on the verge" of making the whole system operate reliably, but the Navy had lost confidence after years of issues and were no longer expecting a return on investment. Rising cost was another factor in cancellation. The unit cost of the shell more than quadrupled, from

US$ The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introdu ...

45,000 in 1997 to $191,000 by 2006 (the Copperhead unit production price was about $30,000), reducing the projected buy from 8,500 to about 3,150. Program research-and-development costs had increased from $80 million to $400 million between 1997 and 2004, with total program costs increasing from $400 million to $600 million. The Navy formally cancelled the ERGM program on 19 March 2008. BTERM was another U.S. Navy developmental round that included GPS guidance in an artillery shell; it too was terminated in 2008 after over four years of development by ATK.

Specifications

* Caliber: 127 mm (5 in) * Length: 1.55 m (5 ft 1 in) * Weight: 50 kg (110 lb) * Speed: >3000 km/h (1860 mph) * Range: 110 km (60 nm) * Guidance:

INS INS or Ins may refer to: Places * Ins, Switzerland, a municipality * Creech Air Force Base (IATA airport code INS) * Indonesia, ITF and UNDP code INS * INS Park, an entertainment complex in China Biology *'' Ins'', a New World genus of bee flie ...

* Accuracy: < 20 m CEP independent of range. * Propulsion:

Solid-propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, th ...

rocket motor A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed jet of high-temperature gas produced by the combustion of rocket propellants stored inside t ...

. * Warhead: 72

DPICM A dual-purpose improved conventional munition (DPICM) is an artillery or surface-to-surface missile warhead designed to burst into submunitions at an optimum altitude and distance from the desired target for dense area coverage. The submunitions ...

submunition A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller submunitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill personnel and destroy veh ...

s (EX 1) or unitary

high-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 exp ...

Program timeline

* 1996 - Program started. * December 2001 - All-up round guided test flight of an ERGM at

White Sands Missile Range White Sands Missile Range (WSMR) is a United States Army military testing area and firing range located in the US state of New Mexico. The range was originally established in 1941 as the Alamogordo Bombing and Gunnery Range, where the Trinity t ...

, NM.EX-171 ERGM Extended-Range Guided Munition - Global Security
/ref> * February 2005 - Successfully test-fired two tactical ERGM rounds. * April 2005 - U.S. Navy closes original ERGM program and re-opens new competition to meet the requirement.Navy Smart Shell Does a Crash and Burn - Strategy Page
/ref> * March 2008 - Navy ends funding to Raytheon, effectively killing the program.Navy ends ERGM funding - Navy Times
/ref>

References

External links

Raytheon Company: Products & Services: ERGM

Missile Systems - Precision Guided Projectiles - Raytheon
* {{cite web, url=http://www.dtic.mil/ndia/2004armaments/DayII/SessionII/03MAJ_Graham_NSFS_Overview.pdf, last=Graham, first=Major Jeff, title=Extended Range Guided Munition (ERGM) Program, work=Brief for the NDIA International Armaments Technology Symposium and Exhibition, publisher=Naval Surface Fire Support Program Office, date=June 2004, accessdate= , archive-url=https://web.archive.org/web/20120927202420/http://www.dtic.mil/ndia/2004armaments/DayII/SessionII/03MAJ_Graham_NSFS_Overview.pdf, archive-date=2012-09-27, url-status=dead Artillery of the United States Cannon-launched guided projectiles

Synopsis

Specifications

Program timeline

See also

References

External links