Abstract: A rocket propellant tank arrangement (40) for storing fuel and oxidizer for launching a rocket includes an oxygen tank (42) for storing liquid oxygen and a fuel tank (52) for storing liquid fuel, wherein the fuel tank is at least partially arranged within the oxygen tank.

Abstract: A recoverable rocket stage (2) for propelling a rocket (100) towards space includes a rocket propellant tank assembly (4) having a generally cylindrical outer shape; at least one engine (6), coupled to the rocket propellant tank assembly (4); and a plurality of drag enhancing elements (8), the plurality of drag enhancing elements (8) forming longitudinal extensions of the generally cylindrical outer shape of the rocket propellant tank assembly (4) in their launch positions and being inclinable with respect to the generally cylindrical outer shape of the rocket propellant tank assembly (4) for return of the recoverable rocket stage (2) to earth.