Squad Mission Support System

The Squad Mission Support System (SMSS) is an unmanned ground vehicle (UGV) developed by Lockheed Martin for the United States Army. It was designed to provide logistical and transport support to infantry squads, particularly in rugged and hostile environments. The SMSS represents a major advancement in robotic support technology, aiming to reduce the physical load on soldiers and enhance mobility, efficiency, and safety during field operations.

Background and Development

The development of the SMSS originated from the U.S. Army’s objective to lighten the logistical burden on troops and to integrate robotic systems into ground operations. Early prototypes, known as Block 0 and Block 1 models, were developed to test autonomy, navigation, and load-carrying capacities.
The system underwent rigorous testing during deployments in Afghanistan between 2011 and 2012, where it carried supplies for light infantry units. These field assessments demonstrated the feasibility of unmanned logistics support on the battlefield and provided valuable insights into the integration of autonomous vehicles within military units. The SMSS became one of the first operationally deployed robotic support platforms tested in real combat conditions.

Design and Technical Features

The SMSS was built as a multi-terrain, all-purpose support vehicle capable of carrying large payloads while maintaining operational flexibility. Its design incorporated a combination of manual, remote-controlled, and autonomous operating modes to adapt to various combat and support scenarios.
Key features include:

• Payload Capacity: The SMSS Block 0 variant could carry up to 1,200 pounds (approximately 544 kg) of supplies, including ammunition, medical kits, water, and batteries.
• Mobility: Designed for high manoeuvrability, the vehicle can navigate slopes up to 30 degrees and rough terrain including mud, sand, and rocky surfaces.
• Operating Modes: It can operate in several modes—manual (with a driver on board), remote-controlled, or semi-autonomous (including “follow-me” and “go-to-point” modes).
• Power and Engine: Equipped with a diesel engine, it offers long operational endurance and can serve as a portable power source for recharging soldier batteries and electronic equipment.
• Sensors and Navigation: Advanced electro-optical and infrared (EO/IR) systems enable obstacle detection and terrain mapping, with options for satellite communication for beyond-line-of-sight control.
• Adaptability: The platform can be reconfigured for various missions, such as logistics transport, reconnaissance, casualty evacuation, and mobile power supply.

Operational Use and Field Testing

During its deployment in Afghanistan, the SMSS was used primarily for logistical resupply missions. It transported equipment and rations to forward bases and remote outposts, reducing the physical strain on troops and the need for vehicle convoys in hazardous areas.
The field trials demonstrated that the SMSS could operate effectively in semi-autonomous mode, following troops or pre-determined paths. It provided valuable support during long-range patrols, particularly in mountainous and arid regions where manual carriage of loads was impractical.
However, challenges were observed in autonomous navigation, especially in complex terrain and densely vegetated areas. The system sometimes required manual intervention to avoid obstacles or to ensure precise movement through unpredictable environments.

Advantages of the SMSS

• Reduced Soldier Fatigue: By carrying heavy loads, the SMSS allows troops to move more efficiently and maintain higher combat readiness.
• Enhanced Tactical Mobility: Troops can operate with lighter personal loads, improving speed and endurance during extended missions.
• Operational Flexibility: Capable of performing diverse roles including logistics transport, casualty evacuation, and surveillance.
• Autonomy and Remote Operation: Enables missions in high-risk zones without exposing personnel to danger.
• Force Multiplication: Acts as a mobile logistics unit, freeing soldiers for combat and reconnaissance tasks.

Limitations and Challenges

While technologically advanced, the SMSS faced several operational and logistical constraints:

• Autonomous Navigation Issues: The system’s obstacle detection and decision-making capabilities were limited in highly irregular terrains or congested environments.
• Payload-Terrain Trade-off: Carrying heavier loads often reduced manoeuvrability and endurance on difficult terrain.
• Maintenance and Training Requirements: The system demanded skilled operators and a supporting technical infrastructure, which added to logistical complexity.
• Programme Competition: Despite its capabilities, the SMSS was not selected for the U.S. Army’s Squad Multipurpose Equipment Transport (S-MET) programme, as other platforms were found to better meet evolving operational requirements.

Broader Military Implications

The SMSS represents a major step in the evolution of robotic support for ground forces. It showcases the potential of unmanned systems to enhance operational sustainability and efficiency on the battlefield. The concept of “soldier load reduction” has gained significant importance in modern military planning, and the SMSS directly contributes to this objective.
The vehicle also underscores the future of human–machine teaming, where robotic platforms operate alongside soldiers to improve safety and performance. It offers valuable lessons for future unmanned ground vehicles, particularly in terms of navigation autonomy, adaptability, and maintenance integration.

Significance and Legacy

The Squad Mission Support System is significant for being one of the first large unmanned ground vehicles deployed for practical combat use. It not only validated the feasibility of robotic logistics but also influenced subsequent military projects focused on autonomous ground mobility.
Its development provided critical insights into how unmanned systems can transform traditional battlefield logistics—shifting the role of robots from surveillance and combat support to direct participation in supply and sustainment operations.