Modern planetary rovers are based on aluminum chassis, but thanks to carbon fiber composites, the weight of such mobility platforms can be dramatically lowered. This paper describes the design of a 6-wheeled rover with a rocker-bogie suspension, adopting carbon fiber laminates and short-fiber-reinforced polymers. This last feature is an innovative approach that fits well with the use of additive manufacturing, allowing for both highly optimized parts and rapid fabrication of spares in future manned missions on the Lunar surface. The structural design was validated against a set of boundary conditions (static analyses) and requirements of launch and space environments (dynamic analyses) as prescribed by European Cooperation for Space Standardization standards. The composite rover was designed to lighten the structure itself and increase the payload-to-total-mass ratio: the composite solution offers a ratio three times higher than the typical rover (ratio from 0.12 to 0.38).