A magnetic recording medium comprises a magnetically soft underlayer having a plurality of cavities in a surface thereof, and a magnetic recording material in the cavities, wherein a surface of the magnetic recording material in the cavities is substantially coplanar with the surface of the soft underlayer. The vanes are attached to each other at their inner ends. An opening may then be formed in the second layer and metal may be selectively deposited over substrate layer. The second member is also attached to the platform. The control system provides, in response to operator requests for propulsion and in response to the state of charge of the batteries, for allocating available power between propulsion and battery charging.