Is space weather a threat to satellites?

Space weather is a significant threat to satellites in orbit. The biggest threat to any human-made objects in space are the solar storms that may substantially increase the flow of charged particles from the Sun. Solar flares emerging from sunspot groups and regions of magnetic anomalies on the solar disc may be associated with phenomena called solar particle events, in which electrons and protons from the Sun are accelerated to relativistic speeds. When these particles hit a satellite, its solar panels and onboard electronics may experience radiation damage that would normally take several years in space to accumulate. These high-energy particles may also cause malfunctions in satellite electronics and memory circuits, causing transient or permanent damage and potentially even causing the loss of the satellite.

Big solar flares are also often associated with coronal mass ejections – huge eruptions with billions of tonnes of matter from the Sun ejected into space at speeds reaching up to 3,000 kilometres (1,864 miles) per second. When such a cloud of plasma hits the magnetic field around Earth, it may trigger a geomagnetic storm that makes the radiation environment for satellites much harsher than it is normally.

Particularly in geostationary orbit, where most of our communications satellites are, parts of the

“These high-energy particles may also cause malfunctions in satellite electronics” Melanie Heil & Juha-Pekka Luntama

satellites may become electrostatically charged, and the onboard electronics can be damaged by the eventual discharge. Geomagnetic storms may also produce very high-energy electrons in the outer radiation belt – ‘killer electrons’ that can permanently damage satellite electronics and kill the mission. Melanie Heil, space weather space segment coordinator in the European Space Agency Space Weather Office, and Juha-Pekka Luntama, head of the Space Weather Office