The problem of having a spacecraft visits a given set of target sites on the Earth within a given time frame is solved. The solution is the optimal natural orbit for the spacecraft. Natural orbit solution will enable the spacecraft to achieve the mission without the use of propulsion. The performance index poses multiple minima and the calculus based methods for optimization are not efficient. Genetic Algorithms are used effectively to find a good solution to the problem. In general, a solution may not be found for a single spacecraft to achieve the mission. In that case, the set of target sites is divided optimally into groups. The optimal solution is found for each group. Each group will have a different spacecraft, or one spacecraft can be used by maneuvering it from one orbit to another.