Sandia LabNews

Sandia team supports development of US Army's new lightweight, high-caliber, self-propelled cannon system

Researchers at Sandia/California have emerged as key players in a US Army program that focuses on the design and manufacture of a lightweight, high-caliber, self-propelled cannon system.

The weapon system, known as the Non-Line-of-Sight Cannon (NLOS cannon), is fully automated and can fire at a sustained rate of six rounds per minute. The artillery system, once completed, must be light and agile enough to fit three vehicles comfortably onto a C-17 cargo aircraft.

According to project manager Nipun Bhutani (8774), Sandia’s primary contribution in the program to date has been a critical adjustment to a laser ignition system that serves as the heart of the NLOS cannon vehicle. The cannon is part of Future Combat Systems (FCS), the Army’s premier modernization program.

BAE Systems is developing this system as part of The Boeing Company/SAIC-led FCS program.

The laser ignition system was developed by the Army’s Armament Research, Development, and Engineering Center (ARDEC), in collaboration with Kigre, Inc. The ignition unit is mounted on the back of the cannon’s gun barrel, where a laser beam is fired through an opening mechanism (the breech) to ignite a charge and launch an artillery shell.

However, says Nipun, the recoil force and shock of the projectile (bullet) discharge had caused an increase in observed failures during early prototype testing.

“The laser ignition system offers much better precision, rapid fire, and automation than the mechanical method, and it’s safer,” Nipun says. “But it’s obviously not going to be an effective long-term solution if reliability cannot be maintained.”

Instead of abandoning the laser ignition concept in favor of traditional, mechanical ignition, the Army called in experts at Sandia who deal with shock issues surrounding a wide range of components.

To absorb the force from the discharge, Sandia proposed a new isolation system between the laser and the breech. Vibration isolation systems are widely used to protect sensitive devices from vibrations or shock produced in their environment. Typical examples include isolating delicate laboratory experiments from floor-borne vibrations, or isolating a car body or airplane frame from engine vibrations.

Sandia, in collaboration with BAE Systems and ARDEC, is developing an isolation system for the NLOS cannon that acts much like a filter and results in much lower shock levels.

In addition to working on the isolation system, Sandia researchers have applied the Labs’ modeling and experimental capabilities to hardening the laser igniter.

In an effort to develop the most effective isolation system possible, the Sandia team needed to model the physics and inner workings of the laser system components. This involved modeling the gun loads and other physical dynamics inside the laser ignition system, particularly as it is fired.

“In keeping with Sandia tradition, we developed an entire systems approach to the problem,” says Nipun. That approach included not only analysis and modeling of the isolation system but building a prototype and further researching the system’s performance and reliability. Sandia also did modeling work on the laser and breech. Sandia is supporting BAE Systems’ test efforts.

One of Sandia’s long-term objectives with its NLOS cannon work, says Nipun, is to enhance its reputation for customer service and strengthen alliances with BAE Systems, ARDEC, Benet Laboratories, and others.

“We want to be known among our current and future customers as the ‘go-to’ lab,” says Bhutani.

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