Space weather observations and the prediction of expected disturbances on ground- and space-based infrastructure are critical for the safety and evolution of our modern society. Space weather events, like solar storms, can have a significant impact on navigation, communication, power grids and other electrical conducting infrastructures. Therefore, space weather predictions are very important, but recently lack a reliable estimation of the geo-effectivity as well as detailed information for regions and systems potentially affected.

In the Sun-to-Earth interaction chain, the plasmasphere is a central source of information in respect to the geo-effectivity of solar storms and not well covered until now. This is surprising since the compression and change of the plasmapause is a direct information source for the strength of the solar wind and solar storm impact. With this project 'Plasmasphere Monitoring for space weather impact prediction' the German Aerospace Center (DLR) and Fraunhofer IPM suggest a mission concept to continuously monitor the movement/shift in the plasmapause boundary, using GNSS and DORIS signals as well as an onboard Langmuir probe on a satellite constellation of three CubeSats, orbiting in polar orbits at altitudes of about 10 000 km. The radial location of the plasmapause is controlled by a combination of the co-rotational and solar wind-driven convectional electric fields and the size as well as shape of the plasmasphere is dependant on the level of geomagnetic activity. Therefore, it represents an indicator of space weather events and early warning can be given to terrestrial and orbital users based on the measurements. Although thousands of ground GNSS receivers provide a continuous, but regional, monitoring of the ionosphere and plasmasphere (without distinction between both layers), the plasmasphere monitoring above 10 000 km is never done and the data will be a unique source for ionosphere/plasmasphere model calibration at higher altitudes.