Supposing a planned long-term manned-flight with a spaceship that has to be fairly large to accommodate many people and meet some requirements like decent shielding from radiation.
Is it better to build a large space ship in total and launch it from Earth, considering places of production, technology available, resources for logistics and costs of fuel, or is it better to construct modules/parts, which are brought to and assembled in space, also considering places of production, technology available (especially for the later assembly), resources for logistics and costs for fuel?
