It seems improbable that a satellite designed to monitor polar ice sheets and floating sea ice could accurately measure a disturbance in Earth's magnetic field. But that is just what ESA's CryoSat mission did earlier this year. This is a story of unique innovation in satellite technology. At the end of last year, the CryoSat mission, which has been operating for almost 16 years, was given a remote upgrade of new software for its platform magnetometer. This instrument is installed on the satellite to ensure it orbits at the right altitude and directs its science instruments toward the right part of Earth's surface. The platform magnetometer is therefore an operational instrument and was not designed to produce scientific data about Earth's magnetic environment.