Scientific objectives and technologies for the solar orbiter dust detector

Sources of Interplanetary Dust Particles (IDPs) and physical processes drive their composition, size, abundance and dynamical evolution. In particular, in the inner solar system, measuring these parameters could improve significantly the comprehension of the processing of IDPs and their origin. Also, recent results indicate that an interstellar dust component is present in the circum-solar environment at least at 1 AU. Solar Orbiter gives a unique opportunity to address the above-mentioned topics, mainly regarding the solar system environment (with contribution from both local and external dust components) inside the Earth orbit. In particular it can address the following issues: • identification of dust sources in the inner solar system; • determination of the relative contribution of dust components and physical effects on them; • characterisation of the interplanetary and interstellar dust flow through the planetary system, including a direct observation of the heliosphere environment effects on dust properties; • determination of mass, size, speed and electrical charge distributions from measurements of individual particles. The importance and technical solutions for a suitable dust detector are discussed, depending also on mission plan and available resources.