The Solar Wind Analyser is a key component of the Solar Orbiter mission. SWA will measure the in-situ solar wind, determining its speed, density and composition. Together with remote sensing instruments, SWA will allow us to confidently relate the solar wind with its source regions.
SWA/EAS – Solar Wind ‘strahl’ electrons will allow an independent determination of the direction of the magnetic field at the spacecraft, and, crucially, will provide more global information on the nature of the magnetic field by providing a diagnosis of whether the local magnetic field line is connected to the Sun at one end, both ends or not at all;
SWA/PAS – Measurements from this sensor will be used to define the state of the solar wind itself (e.g. whether it is fast / slow), together with providing a key means to identify its structure (e.g. the passage of shocks);
SWA/HIS – Information on solar wind composition from this sensor will provide the key connection to spectroscopic remote sensing measurements – providing a means to identify the solar source regions of the ambient solar wind passing the spacecraft.