Like the Orbiter Vehicle of the Space Shuttle was mounted on its external tank, the "gondola", the crewcar of the airship, could be likewise mounted on the last stage of the launch rocket, that would serve as the envelope of the airship.
Like with the Space Shuttle, the external tank should be connected to two solid rocket boosters that provided over 70% of the Space Shuttle's thrust. And like the Orbiter Vehicle, the gondola could have the main engines which are fueled from the external tank.
The empty weight of the Orbiter Vehicle and that of the external tank of the Space Shuttle were 78,000 kg and 26,535 kg, respectively.
Would this be achievable and would it be more economical than using a complete airship mounted on top of the launch rocket ?