Today, more than 16 years of space-weather data is publicly available for the first time in history. The data comes from space-weather sensors developed by Los Alamos National Laboratory on board the nation’s Global Positioning System (GPS) satellites. The newly available data gives researchers a treasure trove of measurements they can use to better understand how space weather works and how best to protect critical infrastructure, such as the nation’s satellites, aircraft, communications networks, navigation systems, and electric power grid.