Abstract: A computer-controlled shock strut for a vehicle suspension system includes an infinitely adjustable damping valve connecting two internal fluid-filled chambers within the strut, such that compression and extension of the strut piston causes fluid to pass between the chambers through the damping valve. A microprocessor-based controller continuously and actively controls the position of the damping valve in response to input signals from various sensors associated with the strut, with the vehicle, and/or with the suspension system, so as to vary the damping rate of the strut to control piston position and motion. The strut also includes fluid supply and return valves which couple the two chambers to a pressurized fluid supply and a fluid return, respectively, to permit fluid to be added to or discharged from the strut. The supply and return valves are also controlled by the controller so that strut length can be controlled.