US Army orders next-gen robot mule to haul a literal ton of gear

Soldiers' new best friend does all the heavy lifting

Soldiers bear a heavy burden while serving their homelands, which is why the US Army has awarded contracts this week to two companies for a new generation of equipment-hauling robots. 

The Small Multipurpose Equipment Transport Increment II (S-MET II) is set to be built by American Rheinmetall Vehicles and HDT Expeditionary Systems, the Army said. The pair were awarded a combined total of $22 million for eight prototype vehicles to be delivered at an unspecified future date. 

The award for Increment II of the S-MET comes rapidly on the heels of the delivery of the original version, built by General Dynamics Land Systems. Sixteen of the original S-MET were delivered to the Army in late 2022, and by early 2024, the call had already gone out for the new one. 

That original version of the eight-wheeled, radio-controlled vehicle, the US Army said, had the ability to carry half a ton of equipment and generate power for portable electronic equipment, along with having capabilities for weapon system mounting and casualty evacuation. 

S-MET II will retain those capabilities, but the Army wants it to be quieter, have double the payload capacity, improved power export capabilities "to enable modern mission payloads like unmanned air systems," a more modular design, the ability to serve as the hub for a wireless mesh network, and "worldwide grid charging" capabilities. 

"S-MET Increment II addresses capability gaps associated with excessive physical burdens, recharging batteries during continuous operations, and reducing sustainment burden for semi-independent operations," said Kyle Bruner, project manager for the Army's Force Projection program. It's not clear if S-MET II will have more autonomy than the first version, or if it will also be radio-controlled by an operator.

The original version of S-MET is based on an existing General Dynamics vehicle, the Multi-Utility Tactical Transport, or MUTT. However, the Army didn't specify in the announcement how the MUTT is different from the original S-MET, or why General Dynamics wasn't selected to build the newer version.

Adios, ruck march

Depending on your military occupation, it's not uncommon for a load of field equipment to weigh in excess of 100 lbs (45 kg). Even if you're young and extremely fit, that's still a lot of weight, and it's incredibly common for soldiers to suffer injuries due to carrying excessive weight over long distances in some of the least supportive footwear known to humanity.

Injuries aside, no one is functioning their best after walking ten miles carrying 100 lbs and wearing a Kevlar helmet – sure, it builds character, but in an actual combat situation, exhaustion can be the difference between life and death.

"The S-MET reduces Soldier load and enhances small unit combat effectiveness by reducing fatigue and injury caused by excessive physical loads, shifting the burden to the robotic platform," Bruner said of the so-called robotic mule. "S-MET supports the Army's mission to implement robotic and autonomous system capabilities with urgency to lessen risk to Soldiers in multi-domain operations."

If the S-MET II is successful, the Army said it intends to acquire as many as 2,195 systems by late fiscal 2027. The original model was being considered for infantry brigade combat teams, explosive ordnance disposal, and security force assistance brigades. It's not immediately clear if the S-MET II will be deployed to additional unit types.

We've reached out to the US Army, Rheinmetall, and HDT with questions, but haven't heard back. ®