As space missions grow increasingly demanding—driven by tighter pointing requirements, larger deployable structures, and more complex operational scenarios—the need for efficient and accurate preliminary design frameworks has become critical. Early-stage design errors or simplifications can propagate into costly redesign cycles, delays, or degraded mission performance. This motivates the development of simulation tools capable of capturing realistic spacecraft dynamics, structural flexibility, and environmental disturbances from the very beginning.

This study presents a high-fidelity spacecraft AOCS simulation framework developed in MATLAB/Simulink and designed to support advanced analysis of flexible spacecraft dynamics under realistic orbital and environmental conditions. The simulator incorporates a comprehensive suite of perturbation models—including gravity-gradient effects, geopotential harmonics, geomagnetic torques, third-body interactions, solar and Earth radiation pressure, and atmospheric drag—and its orbital and attitude propagation have been rigorously validated against Orekit and Basilisk, respectively.

A key feature of the framework is its integration with the Satellite Dynamics Toolbox library (SDTlib), which provides a parametric Linear Fractional Transformation (LFT) representation of the spacecraft’s flexible structure, including uncertain and time-varying parameters. Previous results demonstrate the tool’s applicability to missions involving complex control–structure interaction problems, such as on-orbit servicing using robotic arms.

Through this SDTlib-enhanced architecture, the simulator can efficiently perform high-fidelity nonlinear and linear parameter-varying (LPV) simulations of flexible and dynamically evolving spacecraft. At each simulation step, key structural and dynamic quantities, such as mass properties, inertia tensors, center of mass position and hinge-joint angles are updated based on both internal linearized structural dynamics and external nonlinear orbital disturbances, as well as sensor and actuator dynamics. A case study on the ESA mission BIOMASS demonstrates the simulator’s capability to accurately and efficiently model the deployment of a large flexible antenna, highlighting its ability to handle complex spacecraft missions with high fidelity and computational speed.