ExxoTank

ExxoTank is a Mars-orbiting propellant resupply station intended to support future human missions to Mars by providing a reliable source of fuel for the crew’s return journey. The concept addresses the challenge of transporting enough propellant for a round trip while reducing dependence on producing fuel from Martian resources. Because a single resupply vehicle must remain within the payload and dimensional limits of a Starship launch, the team proposed a constellation of smaller resupply stations rather than one extremely large vehicle. The station carries approximately 119 tonnes of propellant using a Raptor Vacuum engine, with a 3.7:1 oxidizer-to-fuel ratio, and includes solar arrays and batteries, guidance/navigation/control hardware, communications antennas, thermal and micrometeoroid protection, and a robotic refueling arm. The team analyzed the structural frame under severe launch loads, including 6 g vertical and 2 g lateral acceleration, and evaluated the robotic arm for fluid losses, dynamic loads, and structural stresses. Thruster positioning was also studied to determine the thrust, mass flow, burn time, and fuel consumption needed to despin and stabilize the station. The resulting design combines orbital mechanics, propulsion, structural analysis, robotics, power, communications, and thermal protection into a reusable infrastructure concept for supporting crewed Mars transportation.