Solar Orbiter will explore inner heliosphere to determine the links between activity in the magnetic field-dominated regime of the solar corona and their consequences in the particle-dominated regime of the interplanetary medium. These links will be revealed through analysis of observations of the Sun from a complement of powerful, high-resolution optical instruments, together with those from state-of-the-art instruments which sample, in situ, the properties, dynamics and interactions of plasma, fields and particles in the near-Sun heliosphere. In addition, these plasma and field instruments have high temporal resolutions, and thus offer unique possibilities for resolving plasma kinetic processes at small scales.

In order to achieve the mission science goals, high-cadence measurements of 3D velocity distribution functions of the solar wind electron, proton and alpha particle populations are required, together with abundant heavy ions such as O6+ and low iron charge states such as Fe9+ or Fe10+. These measurements will be made by the Solar Wind Analyser (SWA) suite on Solar Orbiter. This investigation is led by the UK (P.I. Prof. C.J. Owen, UCL/Mullard Space Science Laboratory) with major hardware collaborations from international partners.

In this poster we briefly review the mission science goals related to the in situ exploration of the inner heliosphere. We update progress on the SWA sensor build program and discuss sensor and mission operational planning which will ensure we meet these goals under Solar Orbiters challenging constraints and measurement environment.