A new strategy for the design of tracking control laws is presented for line-of-sight (LoS) pointing control of satellites that use only magnetorquers. This strategy makes use of the backstepping approach, and applies to satellites that require the LoS of a single instrument, such as a transmission antenna or camera, to be pointed at a given time, but not both simultaneously. Asymptotic stability of the desired trajectory is proved, provided the target pointing-direction lies outside some critical range. A control law so developed is numerically simulated for a nanosatellite mission scenario to demonstrate feasibility. © 2013 2013 California Institute of Technology.