Photograph of flight hardware, showing a cluster of four colloid thrusters. Two such clusters form the actuators of the Disturbance Reduction System (DRS) on LISA Pathfinder.
Each colloid thruster can deliver a continuously modulated force of between 5 µN and 30 µN. The two clusters of colloid thrusters are controlled by the Instrument Avionics Unit (IAU), which is the dedicated computer of the DRS (see related images). The DRS is provided by NASA/JPL.