The Carbon Monoxide Silicate Reduction System (COSRS) is an innovative method that for the first time uses the strong reductant carbon monoxide to both reduce iron and to evenly deposit carbon. This enables high temperature carbothermal reduction of silicon oxide yielding five times as much oxygen recovery from planetary regolith compared to hydrogen-based reduction systems. COSRS is an in situ planetary resource utilization process that yields useful oxygen and metals by reducing the majority of metal oxides in undifferentiated lunar, asteroidal, and Martian surface materials. The COSRS initially heats the materials to temperatures where the iron-bound oxygen combines with carbon monoxide, a strong reducing agent (reductant). Simultaneously, the produced iron metal catalyzes the disproportionation of carbon monoxide to carbon and carbon dioxide. The temperature is then raised for carbothermal reduction of the silicates, producing carbon monoxide, which is recycled back to the first stage process, and silicon metal. The carbon dioxide created in the iron reduction/disproportionation step is processed with hydrogen in a Reverse Water Gas Shift (RWGS) unit to make carbon monoxide and water. After electrolysis, the oxygen is stored while the CO is recycled to the reactor.