Final work on the algorithms of the attitude control system (ACS) was finished last week.

The pointing accuracy and -stability requirements are fulfilled in all pointing modes (Inertial-, Nadir- and Target Pointing). The support modes (Detumbling, Safe Mode and Idle Mode) are also fully functional.

As the final feature of the attitude control algorithms the so called State Estimation was added. Using the State Estimation, the satellite is now able to estimate its position, velocity, attitude and rotation rates, even if the corresponding sensors are temporarily not available. Internal software models for the Earth's magnetic field and the sun direction, combined with the very robust magnetometers and sun sensors enable the estimation of the attitude and the rates. Thanks to the internal orbit propagator, the Flying Laptop knows its orbital position at all times.

This important milestone marks the beginning of the development of the actual attitude control software. The current MATLAB/Simulink model of the attitude control will be transformed to C code and tested on the MDVE.

- Oliver Zeile