CHEOPS LP project started in February 2021. During the first period, the project team refined the specifications of the low power propulsion system and its components to take account of actual developments in the LEO/MEO satellite market segments. The main system requirements were updated after the requests for information/proposal received from Primes since early 2021. Workshops, and co-engineering sessions with the equipment manufacturers were organized to assess the technical impact of these updates on the sub-systems and to release system and sub-system requirements and design adapted to the current market need. Evolutions and working plan to achieve the maturity levels in the upcoming development phase were presented to the Commission, Experts and PSA members during the Maturity assessment key point and agreed during the 1st annual review. The target levels and associated dates are consistent with the achievement by 2024 of a TRL7 for the low power EPS, the TU and the FMS, and of a TRL6 for the PPU (the LP EPS Functional Design Review was successfully held in July 2023, the coupling tests are planned end 2023 and the Qualification Status Review in 2024). At the end of the first period the TU, PPU and FMS operational compatibility with both Xenon and Kr up to 1kW was confirmed with performance comparable or above the state-of-the-art.
Value drivers were refined and led to analyses of system alternative architectures with improved performance and or new functionality with regards to existing concepts, to meet the target costs.
Improvements were brought to the HYPHEN-2 simulation tool by the implementation of news algorithms better representative of the plasma discharge, the thruster design and the boundary conditions. These studies included alternative propellants and the ability to estimate the system lifetime. Also, significant progress were made in the simulation time (-33%).
To study and analyze the plasma parameters, diagnostics were improved:
- Optical Emission Spectroscopy (OES), which, coupled with a Collisional Radiative Model (CRM) was used during a test campaign on the LP TU and compared to Langmuir probe measurements. The similarity of the obtained internal plasma parameters validate the OES technique, as a very interesting non-invasive diagnostic for its implementation in testing facilities, and even in flight to monitor and detect in real time any drift in the key parameters.
- Time-Resolved Laser Induced Fluorescence (TR LIF), which, correlated to the TU transients or oscillatory behavior, brings precious information about the physics of the processes that cause instabilities or oscillations.
The dissemination activities led to the creation of the project public website and logo. Communication and promotional materials were produced (project templates, conference roll-up and social media - LinkedIn, Twitter, Youtube). About 13 participation or presentations to a congress were done during the first period of the project.
