Methods and apparatus for controlling the attitude of a mobile platform with a resolution suitable for vernier attitude control. In one embodiment a method includes flowing fluid through an orifice of an aerodynamic surface. The method also includes modifying a boundary layer of the aerodynamic surface with the flowing fluid. Another embodiment provides an aerodynamic member of a mobile platform. The aerodynamic member includes an aerodynamic surface, an orifice, an actuator, and a fluid moving member. The orifice is in the aerodynamic surface and the actuator is subject to friction and backlash. The fluid moving member communicates with the orifice and causes the fluid to flow through the orifice to modify the boundary layer of aerodynamic surface.