EOR environment and SADC tool Electric Orbit Raising Radiation Environment and Solar Array Degradation

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The project objective is to provide a user friendly and fast way to predict solar cell degradation due to space exposure. In particular, the provided tool is validated against ground tests. The ground tests are designed specifically to assess core assumptions of the models used in the project. The end result is provided as both a standalone tool as well as integrated in the ESA Network of Models (nom.esa.int). An error of 2% is expected on the results.

EOR environment and SADC tool objectives



The project produced a new environment model, OMEP, as well as a new calculation tool, SCAD, adapted to current and future missions. Ground testing needed to be tuned to target core assumptions of the current theories and methods regarding solar cell degradation.


Added to the enhanced precision regarding the proton belt model, the standalone tool provides the user with the capability to blend the solar cell aging with the coverglass aging. The resulting degradation is closer to the actual solar cell performance loss as the optical layer darkening is now considered. The simulation tool can be used in either omnidirectional mode (space exposure simulation) or unidirectional mode (ground test simulation) to allow for ground testing tuning. Advanced users can also use the post-flight mode to compare actual performance losses (telemetry) with the expected degradation. Sun angle, temperature effect and yearly solar constant variations are considered for a better visibility on model accuracy.


The project outcome is a new environment model especially designed to provide better accuracy in the trapped protons belt region. This model is standalone and can be used outside of the solar cell degradation tool. The degradation tool is also standalone and the user can provide details regarding the mission environment as well as the solar cell structure. Various examples are provided with the tool along with a user manual.

System Architecture

The tool is a modular system and the various intermediate results can be retrieved if needed.

EOR environment and SADC tool system architecture

The architecture of the provided tool is shown in the picture above. This approach is compatible with the NoM platform where one can combine various models from different projects to create one’s own calculation scheme. The SADC can be built back from the individual modules (see figure) or can be tailored by the end user to suite any specific need. For example, the original environment model or degradation models can be swapped with any other compatible model featured in NoM as long as the inputs/outputs are compatible (see NoM taxonomy for more details).


The project is divided into several work packages as per the figure below.

EOR environment and SADC tool project plan


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