That's what Sea Launch used[1]. Note that the drone ship doubles up as a recovery vehicle to ferry back the stage to land. Also a sea launch platform will be a

That's what Sea Launch used[1]. Note that the drone ship doubles up as a recovery vehicle to ferry back the stage to land. Also a sea launch platform will be a permanent structure while the drone ship's purpose is to be a test platform for landing on land. [1] http://en.wikipedia.org/wiki/Sea_Launch http://en.wikipedia.org/wiki/Sea_Launch