In-situ exploration of extraterrestrial area of scientific interest remains largely impossible with the state-of-the-art wheeled rovers. To combine the advantages of wheeled and legged robots, DLR’s Institute of System Dynamics and Control is developing a modular rover with rimless wheels, called Scout. To save time and money, the development of the Scout rover makes extensive usage of modeling and simulation. A detailed multibody model of the Scout rover accompanies the system through all phases following the V-shaped development process. This starts with the detailed modeling, analysis, and optimization of the rimless wheels and other central parts. It continues with simulation tests on the full system along with optimizations. For example, the properties of the “vertebrae” that connect segments together have been laid out following a digital optimization campaign. Subjects of this text are the details of the multibody Scout rover model, optimization on the rover and simulation analyses. A first prototype of the Scout rover has been built 1.5 years after the start of the project. It is already exceeding the requirements and expectations. Such good results would not have been possible this fast without simulation and optimization. Refinement of the simulation model and validation against the hardware are the next steps.