M777 Lightweight 155 mm. Howitzer
A new, winged projectile for a standard 155-mm Howitzer is designed to achieve the achieve the same range as a proposed, ramjet-powered projectile fired by the U.S. Army’s Extended Range Cannon Artillery (ERCA) system, a General Atomics-Electromagnetic Systems (GA-EMS) official said Oct. 12.
The Reuleaux triangle-shaped Long Range Maneuvering Projectile (LRMP) is scheduled to perform the first wing-extension test during a launch test next week, said Gary Hopper, a GA-EMS vice president, on the sidelines of the Association of the U.S. Army’s annual meeting and exposition in Washington.
The test firing be the first chance for the LRMP to display the advanced choreography of its flight profile. A standard 155-mm projectile leaves the howitzer barrel at a spin rate of about 200 revolutions per sec. The six control fins on the LRMP carefully counter that rotation, slowing the spin to about 20 revolutions per sec., allowing the pair of dihedral wings to deploy.
The combination of the wings and the lifting body shape of the Reuleaux triangle airframe are designed to allow the LRMP to achieve a maximum range of about 150 km, Hopper said. The distance can be achieved using a standard, 24-ft.-long, 39-caliber barrel.
The Army is developing the ERCA with a 30-ft.-long, 58-caliber barrel to potentially fire the XM1155 Nammo ramjet-powered projectile for the same distance.
GA-EMS plans to test an all-up round of the LRMP by the end of next year. The LRMP has been self-funded by the company so far, Hopper said.
The LRMP is among several projectiles and powered munitions being developed by GA-EMS. All of the proposed munitions, including a scramjet-powered, hypersonic missile, feature the Reuleaux triangle, in which the three sides of the object are curved at constant width rather than straight.
