That is the best solution for Mars, but you might need to build the rover in a freezer. Tires that would be soft at Mars temperatures would be liquid or worse a

That is the best solution for Mars, but you might need to build the rover in a freezer. Tires that would be soft at Mars temperatures would be liquid or worse at Earth temperatures. For example, you might fill a normal tire mold with diesel, then cool it with liquid nitrogen and there you go -- a lovely tire for Mars that will melt at normal Earth temperatures. You'd still want to go airless probably, due to a lack of repair shops.