Attitude Determination and Control System

ADCS (engl. A ttitude D etermination and C ontrol S ystem ) or AOCS (engl. A ttitude and O rbit C ontrol S ystem ) is in the space technology a common name for the position - and orbit control system of a spacecraft (engl. Spacecraft ) or . satellite .

Such a system typically consists of sensors , the position control computer and actuators . With the AOCS, a GPS receiver or on-board navigation system is usually added, which also enables the orbit position to be determined.

Position control strategies

A distinction is made between the active ADCS / AOCS systems:

• engl. momentum-bias systems
  • Spin stabilized systems
  • Twist-stabilized systems
• engl. non-momentum-bias systems
  • 3-axis stabilized systems.

Sensors

Position control sensors are used to determine the orientation of the spacecraft in space.

• Absolute sensors
  • Star sensor
  • Sun sensor
  • Earth sensor
  • Magnetic field sensor ( magnetometer )
• Inertial sensors
  • Spinning top
  • Accelerometer

Actuators

Position control actuators are used to change the orientation of the spacecraft in space.

• Control nozzles
• Reaction wheels (at least three; more than three, if used redundantly)
• Twist wheel (always only one; at most two, if used redundantly; unlike the other actuators, it is not used for active change , but for passive maintenance of the alignment in space)
• Solenoids
  • Air coils (coils with a hollow inner cross-section)
  • Magnetorquer / Torqrods (reels with iron core )