Not according to the schematics I've seen; http://www.space.com/media/pdf/spc_lib_gdyson_preview.pdf check out the diagram on page 4. One single pusher plate. This thing, as proposed, could lift off, but not steer. At 200 tons, standard manouvering thrusters or retro rockets would not be able to orient the vehicle. It would be impossible, therefore, to stop. The only way it would work, was if it were a cube, and able to eject nukes in every direction.