Magnetic Torque Rods / Magnetorquers

Torque rods are electromagnets mounted on a spacecraft for attitude control. When a current passes through the torque rod, it produces a magnetic field that interacts with the Earth's geomagnetic field, thus producing a torque on the spacecraft and changing its orientation.

Sources

Stickler, A. Craig, and K. T. Alfriend. "Elementary magnetic attitude control system." Journal of spacecraft and rockets 13, no. 5 (1976): 282-287.