A plan for a mission to other planet with return

In a spaceship that wouldn’t have an internal engineering, just the explosion, the fuselage and the launch base, and would be like this the rocket would have a launch base on Earth but what would be the base of launch in other planet, like mars? So the launch base in other planet would be one of the parts of the rocket and would be left behind. Rute Bezerra de Menezes Gondim