- The U.S. Army is testing the Next Generation Rocket Assisted Projectile at Yuma Proving Ground to replace the M549A1 155mm rocket-assisted round.
- The new projectile is designed to extend artillery range beyond the current 30 kilometers while undergoing structural and rocket performance stress tests.
United States Army Yuma Proving Ground is conducting live-fire tests of the Next Generation Rocket Assisted Projectile, a new 155mm artillery round designed to replace the legacy M549A1 and extend the range of current howitzer systems.
According to officials at YPG, the Next Generation Rocket Assisted Projectile, or NGRAP, is intended to dramatically increase the roughly 30-kilometer range that a currently fielded 155mm howitzer shell can achieve when fired at top zone with rocket assistance.
“It’s going to replace the legacy M549A1 rocket projectile that was developed in the 1970s,” said Steve Flores, YPG Long Range Precision Fire Integrator.
The new projectile incorporates a larger rocket motor than current fielded rounds and is being evaluated for structural strength, rocket performance, and compatibility with future larger cannon systems.
“We are testing a new, one-piece joint with a base closure on the end,” said Jonathan Armijo, test officer. “It is a characterization test of the strength of the design, how the projectile holds up to the stresses of firing and how the rocket performs.”
Testers are subjecting the NGRAP to stress conditions by using standard charges augmented with additional propellant to approach the maximum permissible pressure levels for the cannon.
“We have standard charges we upweight with extra propellant to try to reach the maximum permissible pressure for these cannons to put these bullets through the highest amount of stress that they would see in this caliber tube,” Armijo said. “It is a stress test.”
Although the projectile resembles current 155mm rounds in external appearance, the larger rocket motor represents the primary design change. The Army is examining how the round performs under high-pressure firing conditions and how its rocket behaves once in flight.
To collect performance data, YPG personnel are using high-speed cameras and tracking systems. The proving ground’s scientific photography team operates cameras capable of recording up to 100,000 frames per second, though only a portion of that capacity is used for these tests. Pressure gauges inside the howitzer barrel capture internal readings, while radar systems and Kineto Tracking Mount operators monitor the projectile’s flight to the target area.
Following each test fire, teams recover the projectiles to examine structural integrity and dimensional changes.
“We will recover the rounds to measure post gun launch dimensions,” Armijo said.
William Gardner, the Next Generation Rocket Assisted Projectile test lead, said YPG’s infrastructure and environment support extended-range testing.
“There’s year-round good weather here,” Gardner said. “We consider it a top-notch facility that has very good applicability toward extended range tests.”
Yuma Proving Ground has historically served as a primary site for artillery testing, including guided and semi-guided munitions capable of striking targets within meters at extended distances. The current NGRAP effort reflects the Army’s focus on increasing artillery reach while maintaining reliability and compatibility with existing and future systems.