Multi-Needle Langmuir Probe (m-NLP)

Photo: ESA/P.Carril – CC BY-SA IGO 3.0

EIDEL has space qualified the m-NLP system for 10 years of operation on satellites in Low Earth Orbit. The instrument unit is designed and space qualified by EIDEL, while the boom system is developed by the University of Oslo. The intended operational environment for the m-NLP system is Low Earth Orbit (LEO) up to 1000 km alititude.

The space qualification of the multi-Needle Langmuir probe system has ben funded by the ESA General Support Technology Programme (GSTP) under ESA Contract No. 4000109398/13/NL/AK. The project started in November 2013, and delivery of the qualifed Engineering Qualification Model (EQM) to ESA was in March 2018.

The m-NLP IPR is licensed from UiO.

Shown above is a 3D CAD rendering the m-NLP Electronics Unit developed by EIDEL
Shown above is a 3D CAD rendering the m-NLP Electronics Unit developed by EIDEL

History of m-NLP development at UiO

The University of Oslo has for the last 13 years developed a new Langmuir probe system for high spatial resolution measurements of ionospheric electron density, together with measurements of the spacecraft floating potential. The system consists of four miniaturized cylindrical Langmuir probes, and is therefor referred to as the multi-Needle Langmuir Probe system (m-NLP).

The system is tested on six sounding rockets flights from 2003 – 2012 to altitudes of 350 km, and several upcoming CubeSat mission will have the m-NLP system as the science payload, i.e. the QB50 multi-satellite mission. The advantages of the m-NLP system compared to other Langmuir probes are the unprecedented high sampling rate, and the capability of on-board processing of electron density and spacecraft floating potential with low computational power requirements. For the spacecraft operators this means that the can get valuable info on the plasma conditions around the satellite, as well as the spacecraft charging levels. Both at low telemetry cost, and with high time resolution.