LAUSR

The sweeping Langmuir probe instrument is a part of the payload of PICo-satellite for atmospheric and space science observations (PICASSO), an ESA in-orbit demonstrator. It includes four thin cylindrical probes whose electrical potential is swept to measure both plasma density and electron temperature together with the spacecraft (S/C) potential. PICASSO is a triple unit CubeSat of dimensions $340.5~\text {mm} \times 100~\text {mm} \times 100$ mm. The orbit is expected to be a high inclination low-earth orbit. The main issue implied by the use of a pico-satellite platform for a Langmuir probe instrument is the limited conducting area of the S/C, which leads to S/C charging and drift of the instrument’s electrical ground during the measurement. A specific measurement technique that includes the simultaneous measurement of the potential and current of different probes has been developed to retrieve consistent current–voltage characteristics that can be used to estimate the plasma parameters mentioned above.