With an eye on China and Russia, the US Army wants to make its smart munitions more lethal

Worried that its new generation of weapons has a longer range but less destructive power, the U.S. Army wants to develop a new explosive to create powerful warheads.

The Multi-Phase Blast Munition project aims to mix conventional explosives with reactive materials – similar to the way that aluminum is added to high explosives – to maximize blast effects.

The underlying issue is that the Army’s new munitions weapons come at a price: longer range and more sophisticated guided systems in a shell or rocket mean less room for explosives.

“The US Army is developing new munitions that require more space for electronics, sensors, and rocket motors in order to increase range and accuracy,” according to the Small Business Innovation Research solicitation. “As a result, these munitions have less room for payload and lethal mechanisms while still requiring the same performance or in some cases, increased performance.”

For example, new extended-range artillery projectiles, propelled by ramjets just like missiles are, will be able to hit targets 100 kilometers (62 miles) away. However, this is being achieved at the cost of explosive power.

extended-range cannon artillery army munitions — Prior to firing the projectile from the Extended-Range Cannon Artillery members of the team inspect the test item. (Photo by Ana Henderson/U.S. Army Yuma Proving Ground)

“There are several Long Range Precision Fires (LRPF) projects on-going that require significantly longer range munitions, particularly in the 155-mm size (XM1113 & XM1155),” the Army noted. “These munitions will have notably smaller payload volumes and therefore decreased lethality unless new warhead technologies are implemented in these systems.”

The idea is to mix reactive materials into the casing of the munition, thus magnifying the blast effects.

“Based on the type of munition, further improvement of performance can be obtained by the incorporation of reactive materials (RM) in the surrounding casings of HE charges,” the solicitation said. “The benefits of this type of configuration are numerous, and include an ease of incorporation of these RM liners into existing systems, along with the ability to maintain munition design specifications while improving performance.”

For munitions that are already fielded, one option is to replace inert casings with reactive material liners, which would offer the ability “to produce blast performance attributes beyond simple metalized explosives. While the metal content of HE formulations is limited, an RM liner can easily supply a larger mass of the metal additive, thus enhancing blast performance.”

However, there are numerous technical hurdles to overcome. For example, “the performance of blast munitions is currently limited by the incomplete combustion of the metal additives, either within the HE formulations or as part of RM liners,” the Army said. To optimize blast effects, researchers will have to determine the kinetic and thermodynamic interactions between detonation pressure and pressure of high explosive energy release, and the combustion of reactive materials.

Better warheads for smarter Army munitions

army munitions howitzer — A howitzer cannon fires off a blank round during a 21-gun salute in honor of the 88th Regional Support Command’s centennial anniversary at Fort McCoy, Wisconsin on Aug. 19, 2017. The cannons were provided and fired by the 2nd Battalion, 122 Field Artillery Regiment from the Illinois National Guard. (U.S. Army photo by Sgt. Aaron Berogan)

Phase I of the project will involve experimenting with different formulations of high explosive and reactive materials. Phase II will focus on developing optimum mixtures to maximize blast effects, as well as delivering prototype formulations for field testing. Phase III will see this technology handed over to a major defense contractor for incorporation “into next-generation munitions for the Long Range Precision Fires (LRPF), Next Generation Combat Vehicle (NGCV), & Air and Missile Defense (AMD) Cross Functional Teams (CFTs).”

Improved explosives also have dual-use benefits, for example in the mining and timber industries; they can also be used to blow paths through arctic sea ice and glaciers.

The U.S. military is already working on several projects to improve warheads, including Advanced Warheads Technology (AWT) and Advanced Propulsion & Explosives (APEX) projects. The U.S. Navy is working with manufacturers of energetic materials for warheads and propellants.

The Army fears that its current artillery arsenal is outgunned and outranged by Russian and Chinese artillery. The Army’s Long Range Precision Fires program will redress the balance by creating a new generation of munitions that is able to hit targets a thousand miles away, far beyond the traditional reach of field artillery. More accurate shells for armored vehicles, and air and missile defense, will appear. But hitting a target isn’t the same as destroying it. Smarter munitions need better warheads.

Michael Peck is a defense journalist and contributing writer for Forbes. His work has appeared in Defense News, Foreign Policy Magazine, National Defense Magazine, The National Interest, and other publications. He can be found on Twitter and Linkedin.