SERENA: Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo

The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous
measurements from two spacecraft, offering an unprecedented opportunity to investigate
magnetospheric and exospheric particle dynamics at Mercury as well as their interactions
with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA
(Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space
on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for
ion and neutral particle detection aboard the MPO. It comprises four independent sensors:
ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for
planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA
is managed by a System Control Unit located inside the ELENA box. In the present paper
the scientific goals of this suite are described, and then the four units are detailed, as well
as their major features and calibration results. Finally, the SERENA operational activities
are shown during the orbital path around Mercury, with also some reference to the activities
planned during the long cruise phase.