Cell phone companies would have a hard time setting up service on Mars. There are no maps of where communications signals will break up and no way to tell how radio waves will travel through the planet’s thin atmosphere or how the iron-rich soil might blur them, at least not yet. It’s not likely cell phone companies will set up service on the planet anytime soon, but a network could certainly help the National Aeronautics and Space Administration as it sends rovers to explore the remote and often rocky terrain, said Steve Horan, director of the Center for Space Telemetering and Telecommunications Systems at New Mexico State University.