Development and Implementation of an In-Situ Plasma Measurement System for MEO in a Cost-Effective Microsatellite Platform

The Institute of Space systems (IRS) of University of Stuttgart in collaboration with Space Payload Laboratory of International Space University (ISU) is developing an in-situ plasma measurement instrument for characterizing the plasma environment of MEO with improved resolution, thus implementing the NewSpace philosophy in MEO. This experiment is a part of novel small satellite “Research and Observation in Medium Earth Orbit” (ROMEO), which is being developed at the Institute of Space Systems (IRS) targeting Van Allen radiation belt. After initial in-orbit tests in a 600 km sun-synchronous orbit, the satellite will transition to an elliptical orbit (330km × 2500km) using its state-of-the-art water-based electrolysis propulsion system, enabling it to reach MEO. Conventionally, the satellites are designed to withstand the thermal constraints while the radiation effects are rather overlooked. Due to the presence of high-energy particles and unpredictable anomalies in the MEO region the sensitive electronics present in the satellites are at high risk of failure. For resolving these issues, the ROMEO aims to investigate the space weather of the radiation belt using ESA Distributed Space Weather Sensor System (D3S) to measure the space radiation and the Earth’s Magnetic Field, Particle Detector RUBIK to measure cosmic particles, and a Plasma Measurement Instrument to measure the plasma characteristics. The ROMEO shall measure the plasma environment with its space weather payloads throughout its orbital transitions from LEO to MEO. The investigation of near-space environment namely, ionosphere, plasmasphere, lower magnetosphere indicates that the ROMEO is expected to encounter the plasma with an electron density of ~1×10^8 m-3 - ~3×10^12 m-3 and electron temperatures ranging from 0.06eV to 2eV. Different invasive plasma probe methods for plasma diagnostics are studied based on Plasma Sheath theory. An appropriate method is selected based on the small satellite platform. Subsequently, the structural integrity will be analysed using FEA. To simulate the plasma conditions encountered by the ROMEO, Particle-in-Cell (PIC) simulations are performed using SPIS software. To ensure the reliable functioning of the instrument in MEO, environmental testing strategies are studied. Magnetic screening of a Linear Quantum Cascade thruster is proposed to achieve the required range of plasma temperatures. The instrument’s electronics architecture is designed and tested using LTspice, while experimental methodologies, functional validation, and system behavior are methodized using LabVIEW. Furthermore, data handling strategies, operational modes, and radiation mitigation schemes are developed and integrated into the system to enhance robustness and ensure mission success in the harsh space environment.