The CNES Concurrent Design Facility develops and provides free access to the IDM (Integrated Design Model) toolbox dedicated to the design and preliminary dimensioning of space vehicles.
The approach consists of establishing a technical reference framework comprising a description of the spacecraft (CAD, mass, power consumption, etc.) and mission scenarios (modes, trajectories, attitudes, etc.). This structured and standardized model enables engineers to share information, integrate calculation modules and draw up system budgets.

The objective of this poster is to present the new IDM-ACS (Attitude Control System) module dedicated to the calculation of disturbing torques and the establishment of the torque profile that reaction wheels and magneto-torquer bars must produce to compensate for these external torques and to follow commanded attitude profile.
 
The calculated disturbing torques are the torques due to solar pressure, aerodynamic drag, gravity gradient and Earth's magnetic field. Calculations of atmospheric density and Earth's magnetic field are performed, based on standard international models, and the perturbing torques are estimated taking into account the description of the vehicle (geometry and mass), its commanded attitude and trajectory.
These results are used as input for the ‘Torque profiles’ module to calculate the needed torque produced by the reaction wheels and by the magneto torquer bars in charge of wheel desaturation.
 
The presentation will describe the principles of the calculations implemented, the application's user interface and some representative examples performed at at the Concurrent Design Facility at CNES.