[P-CG21] Future missions and instrumentation for space and planetary science

[PCG21-02] Difficulty to Apply DC probe measurement to a samll satellite Mission and its Solutions

*Koichiro Oyama¹, Hui-Kuan Fang¹ (1.Institute of Space Plasma and Sciences, National Cheng Kung University,Taiwan)

Keywords:Tiny satellite, Ionopshere, New instrument

Tiny satellite such a scubsat is expexted to be useful for scientific purpose, especially if the mision is organized as constellation. One field is ionosphere research. Dc Langmuir probe has been used since 1945 to measure two basic parameters (Te and Ne). The measurement with DC probe works only when conductive surface of reference electrode (satellite surface) is large enough compared with the surface area of the electrode. However this requirement is not fullfilled for tiny satellite. Accordingly this leades to serious problem by two reason: (1) potential of the satellite changes as the voltage of DC Langmuir probe is swept, and (2) contamination of both satellite and electrode can't provide us relialbe measurent values.
The paper discusses problems discribed above and propose two possible solutions.