## 3 Workflow and Software  
The multifaceted design of a Cubesat mission presents various engineering challenges. Specifically, one must contend with minimal geometric dimensions, reduced weight for each unit of the platform, and stringent scientific requirements. It is essential to generate and refine a mechanical baseline for the core of the instrument, the sensitive part of CUSP, while harmonizing the different mission requirements. Starting from the phase A design we implemented a method to assess each mechanical part and the internal and external interfaces of the payload. Finally, an iterative optimization preliminary method was developed and is reported here, encompassing various physical aspects (mainly mechanical and thermal) and potentially leading to the refinement of the mission design. The software used for this project are the following:  
* **SolidWorks** SolidWorks is a three--dimensional parametric design software, produced and marketed by Dassault Systemes. Useful for the design of mechanical devices, even complex ones, it involves the creation of 2D and 3D drawings of solids and surfaces, through a parametric geometric system [3]. * **ANSYS SpaceClaim** ANSYS Space Claim is a parametric solid modeling software available in the ANSYS package that operates mainly according to the direct modeling logic, thanks to which it is possible to define the construction and modification operations of the desired geometry, without the need to define interdependent features. * **ANSYS Meshing** ANSYS Meshing is the software responsible for generating the calculation grid. This process is automated in its simplest application although it is possible to add control settings to act directly on those parameters that define the mesh in terms of morphology, topology and dimensions of the constituent cells. * **ANSYS Workbench** The Workbench platform is the tool designed to put in communication the various modeling and numerical analysis software that fall within the ANSYS landscape, facilitating the management of the project that is articulated there through various work steps. Its key feature is to allow the transfer and sharing of input and output data not only between the different tools used in pre and post processing, but also between multiple simulation models (which allows for the easy implementation of sophisticated multi-physical simulations) [4]. * **Systema Thermica** Thermica [5] is a sophisticated thermal analysis software widely used in the aerospace industry to simulate and evaluate the thermal behavior of spacecraft and their components in orbit. By modeling the thermal environment and the heat exchanges between various parts of the spacecraft, Thermica provides accurate predictions of temperature distributions and thermal loads. These simulations are crucial for ensuring that the spacecraft's thermal control systems can maintain operational temperatures within safe limits, thereby protecting sensitive equipment and ensuring mission success. * **Ansys Twin Builder** Twin Builder is a tool that enables the processing of a dataset and the creation of a Reduced Order Model (ROM). The ROM allows for real-time evaluations of field quantities (such as stresses) and supports more informed decision-making during the design phase. This paper presents the development of a working methodology designed to support design modifications and performance enhancements, starting from Phase B of the CUSP mission (Figure 1). The evolution of the mission design relies on the creation of a simplified numerical model, where non-critical features such as fillets, rounds, and secondary attachment points are removed. The model combines 2D shell elements and 3D solid parts, providing a streamlined representation suitable for early-stage numerical assessments. This simplified model serves to validate the initial design assumptions through a series of multiphysics numerical simulations, conducted in compliance with the mission requirements and the relevant European ECSS standards [6] for CubeSat missions.