Dione: A Pathfinder Mission for Understanding the Ionosphere-ThermosphereResponses to Magnetospheric Forcing at High Latitudes

Dione is a NASA small satellite prototype for future constellations that in different configurations can provide global and localized measurements of Ionosphere-Thermosphere responses to magnetospheric energy input in a variety of scales, enabling their better forecast and prediction.

Dione has a comprehensive sensor package which includes four instruments: a miniaturized fluxgate magnetometer providing magnetic field measurements with two sensor heads, an ion sensor that measures vector plasma drifts and can deduce the in-situ electric fields, an electrostatic analyzer that measures precipitating electrons and up-going secondary electrons, and a neutral mass spectrometer measuring total neutral density and composition. Dione is 3-axis stabilized in a circular low-earth (400-600 km), high-inclination orbit, traversing the auroral precipitation and high latitude currents in every orbit, providing simultaneous measurement of both magnetospheric energy inputs and the associated ionosphere-thermosphere responses in latitude and local time. This presentation focuses on the Dione science objectives of probing the cusp and midnight region dynamics by combining in-situ Dione observations with conjunctions with ground radar and all-sky imagers.