Satellites are a necessity in modern life for a variety of purposes (weather forecasting, scientific exploration, long-range communications, etc.). The vehicles that place satellites in orbit are sensitive to natural and rocket-induced lightning threats. That is why NASA developed the LLCC set of rules to assess whether the weather conditions permit the launches. Since its application, incidents such as those of Apollo 12 and Atlas-Centaur 67 have not occurred again. Within these criteria, the ambient electric field plays an essential role and is measured by a network of field mills (electrostatic field sensors) at the Kennedy Space Center.