Satellite Attitude Control & Mission Simulation with Ansys STK | CADFEM

0:20 Welcome to this technical demonstration of ANSYS Systems ToolKit or STK. In today's session, we are going to explore how to transition smoothly from basic orbital scenario setup to high-fidelity physics-based spacecraft attitude co-simulation. We begin inside a standard digital mission environment where our central body is fully rendered. To initialize our space asset, we navigate up to the primary toolbar, click on insert, and select new. This launches the central insert STK Objects dialog window. STK offers multiple methods to build out an operational scenario, ranging from analytical propagation models to direct database queries. From the object list on the left, we select satellite. On the right-hand panel, rather than manually defining the orbit from scratch using classical orbital elements and propagation parameters, we instead choose the option labeled from standard object database.

1:12 This approach allows STK to directly connect with verified and continuously updated global satellite catalogs. Engineers can rapidly initialize operationally accurate mission assets while significantly reducing manual setup time and minimizing configuration errors during early scenario development. In the query interface, we input our specific catalog ID or naming convention to isolate the asset. Once the system cross-references and populates the database match, we select our target satellite. Clicking insert automatically pulls down the real-time ephemeris and data structure directly into our current timeline. With the asset successfully imported, STK immediately calculates and projects its orbital trajectories and ground tracks onto the 3D map. This allows for instant visual validation of line of sight geometries and regional coverage. To begin deeper engineering adjustments, we right click our newly populated object in the browser and open its properties panel. The properties panel serves as the primary engineering control center for this specific space asset. From here, engineers can review orbital propagation settings, validate the integrity and source of the imported ephemeris data, and define precise mission start and stop conditions for the simulation timeline. These configuration controls become especially important when managing longer duration mission analyses, multi-satellite coordination studies, or high-accuracy orbital prediction workflows. Beyond basic orbital pathways, we can adjust the graphical representation of our system. By modifying these visualization attributes, we set the stage for moving beyond standard point mass approximations and stepping into true multi-physics body-fixed coordinate simulations. This transition becomes critical when analyzing realistic spacecraft orientation, geometry interactions, and subsystem visibility conditions. Now, let's transition into high-fidelity spacecraft modeling. Under the 3D graphics properties, we navigate into the vectors configuration tab. This section allows engineers to precisely control which coordinate frames, velocity vectors, attitude references, and directional pointing indicators remain actively visible during simulation playback. Visualizing these dynamic vectors is extremely important for evaluating complex spacecraft behaviors such as nadir pointing, antenna targeting, sensor alignment, and solar array orientation throughout the orbital mission timeline. To ensure that our digital twin more accurately reflects the real physical spacecraft, we now replace the generic orbital marker with a highly detailed 3D CAD geometry model complete with structural components, antennas, and deployable solar arrays.

3:48 By loading this high-fidelity spacecraft representation directly into STK, the platform can more accurately evaluate body fixed coordinate systems, external sensor visibility constraints, solar exposure conditions, and geometric interactions relative to the surrounding space environment. This significantly improves mission realism during advanced attitude and operational analysis. Next, we delve into the core dynamics of the system by launching the attitude simulator. This workspace allows engineers to configure complex rotational kinematics.

4:19 Within these subpanels, we can set up specific initial angular velocities, select rigorous numerical integration schemes like Runge-Kutta formulation, and incorporate environmental torque disturbances like solar radiation pressure and atmospheric drag. Together, these models allow for highly realistic spacecraft attitude prediction and stability analysis. To validate real-world flight software and onboard control behavior, STK also supports direct co-simulation with external programming environments and custom engineering logic. By expanding the control configuration panel, we browse and link an external Python-based control script. In this case, our custom attitude_torque_controller.py implementation. This integration effectively bridges software development with high-fidelity environmental simulation, enabling real-time control algorithms to continuously interact with the STK solver during execution. The result is a far more realistic closed-loop spacecraft dynamics workflow. To validate real-world flight code, STK supports direct co-simulation with external programming environments.

5:23 By expanding the control configuration, we browse and link an external Python script. In this case, our custom attitude_torque_controller.py. This bridges the gap between software development and environmental physics, feeding real-time control loop logic directly back into the STK solver. This seamless workflow demonstrates the power of Ansys STK for end-to-end mission design. By combining actual database tracking assets, high-fidelity geometry modeling, and custom control algorithm co-simulation, engineers can fully verify satellite attitude behaviors and performance long before the physical hardware ever leaves the ground.