Think your network is hard to manage? Try remote diagnosis and repair when you’re relying on radio signals from Mars. Eighteen days after landing on Mars, the robotic explorer named Spirit squawked in distress and went silent for nearly 24 hours. Listening anxiously for any sign of life were navigators at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif. They had to fix a broken interplanetary communications link that reached more than 100 million miles (and counting-the distance keeps growing as the orbits of Earth and Mars draw apart).