A 1959 NASA depiction of the Ernst Stuhlinger “Umbrella” ship. This design was nuclear-electric, the electricity powering a bank of ion engines providing a trickle of high ISP thrust. The large circular “umbrella” was the radiator for the nuclear reactor, located at the far end of the “handle.” This design is a little different from the usual depiction with the crew compartment divided into two semi-toroidal segments. Normally this design is shown with a single torus with a maximum diameter much smaller than that of the radiator; here the crew compartments are shown to be relatively gigantic. I assume that this is artistic license as it also depicted the crew compartments as having *vast* circular windows in the floor. The crew compartments would spin (apparently independent of the rest of the ship) to generate some amount of artificial gravity to keep the crew healthy.
