The huge robotic mule developed by Boston Dynamics on behalf of the U.S. Marines has been put down for good.

Called the Legged Squad Support System, or LS3, it was often described as a robotic dog because of its appearance, hobbling about on four legs while carrying cargo for soldiers on the battlefield, according to an NBC News report.

The Defense Advanced Research Projects Agency (DARPA) funded the program in the hopes of creating a platform that could carry up to 400 pounds of gear in support of Marines, and able to run for 24 hours straight on a 20-mile mission over rough terrain, navigating itself from both visual and verbal cues.

But what ultimately killed it was its complete lack of stealth. The platform featured a gas-powered engine, making it nothing more than an extremely loud robot that would betray their location. It made the robot essentially useless for the Marines.

It’s not necessarily the end of the technology — many programs are experimental in nature and while they don’t end up seeing the field, the technology enhancement inform future programs.

Instead, the Marines are looking at LS3 not as a failure but as a “waypoint” of development toward unmanned systems that could do important jobs like lightening the load for Marines.

“LS3 is a rough-terrain robot designed to go anywhere Marines and Soldiers go on foot, helping carry their load,” Boston Dynamics describes the robot on their website. “Each LS3 carries up to 400 lbs of gear and enough fuel for a 20-mile mission lasting 24 hours. LS3 automatically follows its leader using computer vision, so it does not need a dedicated driver. It also travels to designated locations using terrain sensing and GPS. LS3 began a 2-year field testing phase in 2012. LS3 isfunded by DARPA and the US Marine Corps.

“Boston Dynamics has assembled an extraordinary team to develop the LS3, including engineers and scientists from Boston Dynamics, Carnegie Mellon, the Jet Propulsion Laboratory, Bell Helicopter, AAI Corporation and Woodward HRT,” the company added.