Not only satellites are vulnerable to the Sun's variability. Astronauts are also at risk. Sergei Ardeyev, a Russian cosmonaut who spent time on the MIR space station, considered a period of high solar activity a terrifying experience. He recalls seeing strange flashes of light. It is well known that high energy proton radiation can destroy the body's cells.
Space weather modelling With the establishment of global space weather studies, help is available.
A network of space weather centres around the world collect real-time data from satellites and ground stations. The ultimate aim is to use these data in space weather models, which can advise when power companies should isolate vulnerable parts of their grid system, when GPS users should switch to other navigation systems, when satellites can be shut down, and when astronauts should retreat to safe quarters. In order to make accurate predictions, it's necessary to understand the physical processes involved in the flow of energy from the Sun to Earth. This is currently underway worldwide, and in the USA it has culminated in the National Space weather Program, an interagency initiative with the National Science Foundation, NASA, the Department of Defence and the National Oceanic and Atmospheric Administration, as the major players. This coordinated effort incorporates physical understanding with model development and observations.