Imaging the solar wind – magnetosphere interaction with SMILE

The solar wind magnetosphere interaction has been studied since the first spacecraft in-situ observations in the late 60s. Since then, many missions have made observations of this interaction, first with single point measurements and later using multi-point observations. These observations however lack the full view of the magnetosphere and only statistical studies over long periods of time have been able to provide a global perspective. The SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) mission will give an instantaneous image of the dayside magnetosphere and its interaction with the impinging solar wind.SMILE is a novel self-standing mission dedicated to observing the solar wind - magnetosphere coupling via simultaneous soft X-ray imaging of the magnetosheath, magnetopause and polar cusps, UV imaging of the northern hemisphere auroral oval and in situ solar wind ion and magnetic field measurements. Remote sensing of the magnetosheath and cusps with soft X-ray imaging is made possible thanks to solar wind charge exchange (SWCX) X-ray emissions known to occur in the vicinity of the Earth's magnetosphere. SMILE is a joint mission between ESA and the Chinese Academy of Sciences (CAS) due for launch in quarter 2 of 2026 from Kourou on a Vega C rocket. SMILE science goals as well as the latest scientific and technical developments, jointly undertaken by ESA, CAS and the international instrument teams, will be presented. SMILE will be complemented by ground-based observatories as well as by theory and simulation investigations. A special issue of Space Science Reviews presents the science, mission, spacecraft, instrument, ground segment, modelling activities and public engagement (https://link.springer.com/collections/cfeghhfceb).