DEFINE – a multidisciplinary 3d digital models for AIT

Simulation and testing play a big role in the development of complex products, such as, satellites. Currently, a wide variety of digital models are used during the Assembly, Integration and Test (AIT) phases of such systems at ESA, in particular when dealing with multi-disciplinary aspects and multi-physics phenomena, e.g. thermoelastic behaviour. The models often contain different kinds of information at different levels of detail. Establishing and maintaining the true baseline of the item under test and the test facility, parameters, as well as the combination of diverse physical parameters is a cumbersome, time-consuming and error-prone procedure. Defining a format capable of maintaining the same configuration as during the tests is therefore a crucial step.

Since 1994 when the first ISO 10303 STEP standard was released, "STEP" (Standard for the Exchange of Product Model Data) has become the global reference for neutral open standard representation of 3D geometry and topology. Since then, several editions were released, allowing a larger amount of information to be captured. Exploitating this enhanced standard could help with representation of the space system during a space craft’s lifetime.
An activity between Jotne, Norway, and GSTP has improved the integration of 3D digital models to make them more efficienct and effective when they are used during these assembly, integration and test (AIT) procedures and fully integrated it into the overall space system lifecycle.  The activity has identified issues in models across AIT processes and the deviations between the simulation and testing parameters. It has also made it easier to locate processes for AIT models and documents.

Called the DEFINE Project, it is a contribution to the ESA Agenda 2025 by supporting “digital continuity throughout the life cycle of projects” and “enabling the development of digital twins”. DEFINE addresses daily issues in AIT processes at the Agency amd shows how these could be overcome.  Beyond addressing the internal needs of AIT at the Agency, DEFINE provides a general foundation of a digital twin for spacecraft. Extensions into other lifecycle phases, such as, conceptual design and spacecraft operation, and other domains, such as, kinematics and electrical wire harness are being considered.

GT1P-007MX closed in 2022 and was presented at the Final Presentation Days in March.