Laboratory measurements of the performances of the Sweeping Langmuir Probe instrument aboard the PICASSO CubeSat

Abstract. The Sweeping Langmuir Probe (SLP) is one of the instruments on board triple-unit CubeSat PICASSO, an ESA in-orbit demonstrator launched in September 2020, which flying at about 540 km altitude. SLP comprises four small cylindrical probes mounted tip solar panels. It aims to perform situ measurements plasma parameters (electron density and temperature together with ion density) spacecraft potential ionosphere. Before launch, instrument, accommodated electrically representative PICASSO mock-up, was tested a chamber. shown that traditional orbital-motion-limited collection theory used for cannot be applied directly interpretation because limited dimensions respect Debye length Nevertheless, this method can adapted take into account short probes. To reduce data downlink while keeping most important information current-voltage characteristics, includes on-board adaptive sweeping capability. This functionality has been validated both chamber space, it demonstrated reduced number points electron retardation saturation regions well resolved. Finally, effect contamination probe surface, serious issue analysis, investigated. If not accounted properly, could lead substantial errors estimation temperature.