the surface to retrieve a marsupial rover the airship could home in the signal from the rover and lower an end effector at the tether end the end effector will attach to the rover and the rover can then be lifted using the winch to rewind the tether line and or by lifting the aircraft 10 higher into the atmosphere the aircraft 10 could also vary its buoyancy using the ballonets etc and land at selected locations for extensive scientific research onsite when finished at one site the aircraft 10 could then increase its buoyancy and take off to fly to another site the aircraft 10 could also lower sensors into lower portions of the atmosphere but without landing the sensors onto the surface for scientific purposes such as sampling of atmospheric conditions imaging etc in the areas below the aircraft 10 in a further embodiment of the invention which may be applicable for high altitude applications on earth the helium or other lifting gas is included within expandable balloons positioned within the larger envelope the larger envelope is pumped or otherwise provided with air which when combined with the helium in the expandable balloons therein maintains the envelope in the desired shape e g airfoil shape the outside air.