Future exploratory missions of celestial bodies in the solar system will require spacecraft capable of landing precisely near to predefined targets, such as places of high scientific interest usually on topographically hazardous terrains, human outposts and pre-positioned assets. This thesis work analyses and implements the guidance problem for a pinpoint landing on Mars. Which requires finding a feasible reference trajectory to safely land a spacecraft on the Martian surface precisely close to a predefined target, optimizing at the same time the fuel consumption. The Lossless Convexification (LCvx) theory is identified as a very promising method to solve this type of problem.