The Extended Range Guided Munition was a

precision guided A precision-guided munition (PGM, smart weapon, smart munition, smart bomb) is a guided munition intended to precisely hit a specific target, to minimize collateral damage and increase lethality against intended targets. During the First Gulf ...

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

-assisted 5-inch (127 mm) shell (projectile) development by

Raytheon Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitali ...

for the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...

. The program was cancelled in March 2008 after twelve years of development and over 600 million dollars in funding.Navy ends ERGM funding - Navy Times
/ref> The developmental round was designated EX 171.
/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 would fins deploy and the rocket motor would ignite, lifting the munition to at least 80,000 feet (24 km), after which the canards would deploy and guide the ERGM to the target using

GPS The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...

guidance. It was to be used on ''Arleigh Burke''-class destroyers (hulls DDG-51 through 112). 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 targe ...

. 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 (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...

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 The Ballistic Trajectory Extended Range Munition (BTERM) was a failed program to develop a precision guided rocket-assisted 127 mm (5-inch) artillery shell for the U.S. Navy. The program was originally named the Autonomous Naval Support Round ...

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 * 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 other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...

rocket motor A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordan ...

. * Warhead: 72 DPICM

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 vehicl ...

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 expl ...

Program timeline

* 1994 - Program started. * December 2001 - All-up round guided

test flight Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. D ...

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 as the White Sands Proving Ground on 9July 1945. White Sands National P ...

, 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.

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 shells

Specifications

Program timeline

See also

References

External links