The modern day expeditionary warfighter faces extraordinary challenges in the battle field and being a beast of burden should not be one of them. Currently the dismounted warfighter is impeded with carrying over 100lbs of tactical gear and supplies for multiday missions in remote territory. Expeditionary forces are also facing an energy and logistical crisis getting water, fuel, and batteries to the tip of the spear. Finding ways to enable self-sufficiency and reducing resupply tethers for small unit operations is a high priority for the armed forces. The Hybrid Electric Autonomous Tactical Support System directly and efficiently tackles both problems head on by synergizing efforts to lighten the load and self sustaining base power by combining the capabilities of the Ground Unmanned Support Surrogate (GUSS) and the Experimental Forward Operating Base projects. Hybridization of the drivetrain of the GUSS vehicle will provide the reliable power for onboard autonomous systems and also enable silent operation modes. The hybrid onboard generator can efficiently provide generous amounts of exportable DC and AC power on demand and is an ideally sized backup/primary power system for small unit bases and forward command posts. The vehicle's onboard energy storage and generator system can also be linked with renewable energy sources to demonstrate the tactical smart mini grid concept. This thesis develops the power requirements for an autonomous system, GUSS mission derived hybrid electric drivetrain specifications, and Marine Corps small echelon bases for the development of the multifunction Hybrid Electric Autonomous Tactical Support System. / Master of Science