A system for in-flight attitude control and side-force steering includes a thruster body and a plurality of valves capable of generating side thrusts put into communication with the thruster body. The valves are arranged in two sets of valves spaced apart from each other towards the front and towards the rear of the thruster body in substantially symmetrical manner relative to the center of gravity of the vehicle situated on a longitudinal axis (A) of the vehicle. Each set comprises a first pair of valves generating thrust in opposite directions along axes that are not in alignment and are parallel to a first axis, and a second pair of valves generating thrust in opposite directions along axes that are not aligned and are parallel to a second axis. The first and second axes are distinct and perpendicular to the longitudinal axis of the vehicle.