Extended Range Guided Munition

The Extended Range Guided Munition was a precision guided rocket-assisted 5-inch artillery shell development by Raytheon for the U.S. Navy. The program was cancelled in March 2008 after twelve years of development and over 600 million dollars in funding [http://www.navytimes.com/news/2008/03/defense_ergm_032408/ Navy ends ERGM funding - Navy Times] ] . The developmental round was designated EX 171. [http://www.designation-systems.net/dusrm/app4/ergm.html Raytheon ERGM (5" Projectile MK 171) - Designation Systems] ] ERGM consisted of three major subsections; propulsion (rocket motor), warhead, and Guidance, Navigation and Control section. ERGM is fired from the 5 inch Mark 45 gun at which point the rocket moter would ignite and lift the munition to at least 80,000 feet when the fins and canards would deploy and guide the ERGM to the target based on GPS guidance. It was to be used on Arleigh Burke class destroyers (hulls DDG-81 through 112).

Despite the long development time the ERGM never worked as reliably as the older but more expensive laser guided M712 Copperhead. During development, the ERGM failed several tests in which the tail fins failed to deploy, rocket motors did not ignite or the electronic components did not survive the stress of being shot from a deck gun. [http://www.navytimes.com/news/2008/03/dfn_ergm_032008/ Guided munition may be canceled - Navy Times] ] Rising cost was another likely factor in cancellation. The unit cost of the shell more than tripled, from $45,000 in 1997 to $191,000 by 2006, reducing the projected buy from 8,500 to about 3,150. BTERM is another U.S. Navy developmental round that includes GPS guidance in an artillery shell. XM982 Excalibur is a U.S. Army round in development.

pecification

* 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: GPS/INS
* Accuracy: <20 m CEP independent of range.
* Propulsion: Solid-propellant rocket motor.
* Warhead: 72 DPICM submunitions (EX 1) or unitary high-explosive.

Program status

* 1994 - Program started.
* December 2001 - All-up round guided test flight of an ERGM at White Sands Missile Range, NM. [http://www.globalsecurity.org/military/systems/munitions/ergm.htm EX-171 ERGM Extended-Range Guided Munition - Global Security] ]
* 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. [ [http://www.strategypage.com/dls/articles2005/20054172332.asp Navy Smart Shell Does a Crash and Burn - Strategy Page] ]
* March 2008 - Navy ends funding to Raytheon effectively killing the program.

References

ee also

* Ballistic Trajectory Extended Range Munition

External links

* [http://www.raytheon.com/products/ergm/ Raytheon Company: Products & Services: ERGM]
* [http://www.raytheon.com/feature/pgp/ Missile Systems - Precision Guided Projectiles - Raytheon]