Attitude Control System
From RHESSI Wiki
The Attitude Control System (ACS) consists of many separate instruments which all work together to control RHESSI's pointing. The Fine Sun Sensor (FSS) provides the spacecraft with high-bandwidth solar positions. This information is used to direct current to the Torque Rods in order to keep the RHESSI's pointing consistent. The Torque Rods interact with earth's magnetic field in order to create small restoring forces. Very rarely, they are also used to stabilize RHESSI's spin or to do offpointing maneuvers. For more information click here.