Attitude Determination and Control System (ADCS)

Team Leader: Maxime Barthélémy (Aerospace Engineering, 2rd cycle)

ADCS

The attitude determination and control system (ADCS) is the module of the satellite aimed at stabilizing and then orienting the satellite towards a given direction.

When the satellite is dropped by its launcher, it certainly will not be stable but it will twist upon itself. The first mission of this system is thus to stabilize the satellite.

Then, the system has to control the attitude of the satellite. Its orientation is a critical part of the mission. Indeed, the satellite needs to point its solar panels towards the sun to get the most power possible and its attitude has to be set to the correct value, to use the ion drop system in order to change the orbit or to deorbit the satellite.

Two different parts compose the ADCS:

  1. First, the data from the sensors (gyroscopes, magnetometers, accelerometers, sun sensors) have to be collected and used to determine the satellite attitude. An EKF (Extended Kalman Filter) is used to achieve the determination

  2. Then, a control law is followed to use properly the actuators (reaction wheels, magnetorquers) in order to set the satellite attitude to the appropriate value.