During two weeks in late October and early November 2003, a series of large solar events led to high levels of energetic particles in geospace and produced overlapping large geomagnetic storms on 28-30 October. These storms caused effects ranging from power grid failures to satellite shutdowns. A Japanese satellite was lost completely, the U. S. Federal Aviation Administration issued their first-ever high radiation dosage alert for high-altitude aircraft, and astronauts in the International Space Station had to retreat into their heavily shielded service module.