Hybrids combine aerostatic buoyancy and aerodynamic lift. Atmospheric satellites remain aloft through atmospheric lift, either aerostatic/buoyancy (e.g., balloons) or aerodynamic (e.g., airplanes). In most winds the aerodynamic lift is greater than the aerostatic lift from the helium. Typically, conventional aerostatic bearings are implemented with chambers and canals. This pressure may be generated externally (aerostatic) or internally (aerodynamic). Since the late 1980s, aerostatic bearings with micro canal structures without chambers are manufactured. Theoretically, an aerostatic vehicle could be made to use a vacuum or partial vacuum.