Characterising Space Weather Risks for LEO SmallSats Using the ESA Space Weather Service Network.

SmallSat missions in Low Earth Orbit (LEO) operate in an environment that can change rapidly in response to space weather. Limited design margins, growing levels of autonomy, and the increasing number of satellites in orbit make it essential for operators to understand and anticipate space weather–driven risks. This paper focuses on three operationally significant categories: atmospheric drag, spacecraft charging, and particle radiation induced effects.

Atmospheric density in the upper thermosphere can increase significantly during periods of enhanced solar and geomagnetic activity, leading to accelerated orbit decay and more frequent orbit control manoeuvres. Variations in the plasma environment, particularly at high latitudes can result in surface charging, increasing the risk of electrostatic discharges and associated system anomalies. In addition, radiation from trapped particles (especially in the South Atlantic Region), solar energetic particles, and galactic cosmic rays contributes to single event effects and the long-term degradation of spacecraft components, affecting mission performance and lifetime.

The ESA Space Weather Service Network provides a coordinated European capability for monitoring, nowcasting, forecasting, and analysing the space environment across multiple user communities. All services include a wide range of data visualisations, alerts and tailored domain expertise and are accessible through the ESA SWE Portal. Through this portal, operators can find timely information on atmospheric density, particle radiation, and charging-related conditions relevant to LEO missions.

This paper demonstrates how these capabilities can support SmallSat operators in characterising the space environment and support pre-operational risk assessments. Selected use cases illustrate how such vital information can improve space situational awareness, and aid post-event analysis.