The Methane to Aromatics on Mars (METAMARS) system is anin situresource utilization (ISRU) technique that converts methane produced from the carbon dioxide in the martian atmosphere to low hydrogen content liquid aromatic fuels for an Earth Return Vehicle, thus greatly increasing the leverage of the hydrogen imported from the Earth. More importantly, the METAMARS system reduces the amount of hydrogen imported from Earth by a factor of four, leading to dramatic reductions in mission cost. This project involves design and construction of two fully functional oxygen/aromatic hydrocarbon production facilities (brassboard and protoflight) sized to produce 1 kg of bipropellant per day. Because aromatic fuels contain only about one hydrogen atom per carbon atom, the METAMARS system gives extremely high leverages on the order of 53 in the production of fuel and oxidizer for a Mars Sample Return (MSR) mission and human Mars missions. In addition, there are extensive potential commercial applications for the technology in converting trillions of cubic feet of stranded natural gas into easily transportable liquid aromatic products. © 2004 American Institute of Physics