Reaction Wheel Unit (RWU)
The RWA is a rotating inertial mass, driven by a brushless DC electric motor. When power is applied to the motor, the wheel accelerates, causing the satellite body to which the motor housing is attached to rotate in the opposite direction due to the induced counter torque.
Coarse Sun Sensor (CSS)
The CSS is a rugged, highly reliable, self-redundant device designed to detect sunlight in potentially a hemispherical field of view (FOV).
The FSS is an analogue sensor, based on the use of a quadrant detector which is capable of measuring the solar aspect angle in two axes. The FSS provides four quadrant output voltage and a sun presence output voltage.
Mini Fine Sun Sensor (Mini-FSS)
The Mini Fine Sun Sensor (Mini-FSS) is designed to deliver exact information about the position of the sun. This information is used for yaw steering of the spacecraft and therefore applied in earth pointing devices and solar array orientation.