Attitude Determination and Control (ADCS)

The attitude determination and control subsystem is tasked with identifying the location and the orientation of the satellite at all times during the orbit. It is also designed to change the orientation of the satellite to get pictures of the desired target area.

Reaction wheels on the mechanical structure

One of the two main OBCs is almost exclusively performing the ADCS task. The satellite uses a multiple components to autonomously resolve the position and orientation and to change the orientation of the satellite:

  • a GPS receiver serially connected to the OBC providing accurate position determination
  • an independent orbit propagator based on the SGP4 model is implemented on the OBC for rough estimates of the position
  • a 3 axis magnetometer is used to measure the magnetic field values at the present position
  • an IGRF11 model implemented on the processor estimates the magnetic field at the present location and compares it to the magnetometer measurements identifying the orientation of GOLIAT's reference frame with respect to the an Earth based reference frame
  • to change the orientation GOLIAT integrates two reaction wheels situated on perpendicular axes which are commanded independently by the OBC.

    Reaction wheel assembly

Time since launch: