Attitude control system

The attitude & orbit control system (AOCS) controls the attitude and position of a complete space vehicle or satellite. Based on this function, the spacecraft orients its solar generators, thermal radiators, thrusters and particularly its payload units, optical instruments and antennas. 

OHB, as system house, controls for all phases of a space program the related AOCS activities  or is directly responsible for:

  • the architecture and design of the AOCS subsystem
  • the development of the control software
  • the integration of AOCS Units (sensors and actuators)
  • and for verification and validation of the integrated attitude control system as well

The attitude control system comprises tested and flight-proven components (star sensors, gyroscopes, momentum wheels, thrusters) which are specified by OHB and supplied by specialised companies. The system added value results from the appropriate selection, the combination of all elements, and from the AOCS Software.

One key process in this respect is the mathematical modelling of the AOCS units, the satellite dynamics and the environmental influences. Thus it becomes possible to perform tests and analyses under simulated space conditions. The necessary simulators and test benches are developed as well.

OHB has extensive experience in all aspects pertaining to attitude control, such as:

  • the development and operation of cost effective attitude control systems for small and mid-sized satellites (BREMSAT, SAFIR, ABRIXAS, MITA, AGILE)
  • contributions to the modelling, development and successful testing of the automatic landing system for ASTRA/PHOENIX (in collaboration with EADS)
  • full-scale development of a dynamic and high-precision attitude control system for the reconnaissance satellites of the German Federal Armed Forces (SAR-Lupe)

Current activities include:

  • the development of the attitude control system for the EnMap scientific satellite
  • the overall responsibility for the attitude control system of the geostationary SGEO satellite series, based on novel star sensors and electric propulsion
  • the operation of the SAR-Lupe satellite constellation (5 satellites)
  • the AOCS development for the European navigation satellites (14 satellites)
  • and the development of a highly accurate attitude control system for 6 MTG (Meteosat third generation) satellites, in close cooperation with Thales Alenia Space.