Robots decommission 700,000 submunitions for recycling

A team of nine robots developed by Sandia National Laboratories (SNL) has disassembled or “demilitarized” 700,000 submunitions at the US Army’s Anniston Munitions Center Multiple Launch Rocket System Recycle Facility in Alabama. The new system not only makes such decommissioning faster and safer, but it also allows the Army to recycle the components for the first time.

Getting rid of obsolete or out of date munitions has been a major problem ever since the invention of gunpowder. Up until relatively recently, the only alternatives have been to explode them, bury them, burn them, or dispose of them at sea. None of these are ideal and all them have serious safety and environmental issues as well as being expensive, so finding alternatives is a high priority for major military powers.

One example of this is the Multiple Launch Rocket System, which was developed during the Cold War by Britain, the United States, West Germany, France, and Italy. It was in production from 1983 to 2003 and used a track-mounted rocket launcher that fires 12 rounds at a time, each of which contains 644 M77 grenades.

That makes disposing of these submunitions a very big job as the system goes out of service. To address this, the US Department of Defense-funded SNL project developed, built, and programmed a robotic system that not only makes the submunitions safe, but also recycles the aluminum warhead skin, steel grenade bodies, and copper.

Though the robots are overseen by human operators, the system removes workers from harm’s way and uses computer vision to detect any anomalies in individual rockets as they are dismantled and alert their supervisors if there are any problems the robots can’t handle.

According to SNL, the robots themselves are standard commercial models that have been modified for their particular tasks. This involves going through nine steps where the warheads are cut into their separate foam-packed sections, then moved on to the next steps or cells, where the grenades are removed from the foam. After that, each grenade is defused, rendering it harmless. To do this, the robots need to be able to move and rotate the packs and munitions precisely.

“Part of the challenge is when you demilitarize warheads like this, you’re working on munitions that are 10, 20, 30 years old,” says Bill Prentice, Sandia software lead for the project. “You test on inert munitions that are in pristine condition, but when you start cutting apart warheads and looking at live grenades, they might have some environmental effects that cause process abnormalities, such as grenades being stuck together during removal.”