Attitude Determination and Control Systems
The ADCS uses an array of sensors, including an Inertial Measurement Unit (IMU), a sun sensor, and a magnetometer to determine the current kinematic state of the satellite. This is used in combination with physical models and the previously known kinematic state to produce a precise pointing vector in an algorithm called a Kalman filter.
The ADCS Flight computer
Sun sensor close-up
Knowing the satellite's pointing direction, the ADCS will then decide the optimal direction to point the satellite. After computing this direction, the ADCS computers will send commands to the satellite's actuators, the magnetorquers. By passing current through an electromagnet, we can generate a magnetic dipole in the satellite, which will exert a torque against Earth's magnetic field, allowing us to aim the body of the satellite.
The full magnetorquer array, with X and Y coils on the left and Z coil on the right