A rotary steerable drilling system can be positioned in a subterranean formation to steer a drill to form a wellbore in the subterranean formation. An orientation of a steering valve, which is positioned in the rotary steerable drilling system, can be adjusted to cover each channel of one or more channels of a valve seat adjacent the steering valve to deactivate each steering pad of one or more steering pads of the rotary steerable drilling system. The orientation of the steering valve can be adjusted to activate at least one steering pad of the one or more steering pads of the rotary steerable drilling system.