Disney’s 1957 TV program “Mars and Beyond” introduced the world to a spacecraft design like nothing ever before seen – the “Umbrella Ship”.
The ion-drive Atomic Umbrella Spaceship, so called for obvious reasons. The umbrella is a vast radiator surface for dissipating the heat from the reactor at the end of the long boom.
The original source was this paper: ELECTRICAL PROPULSION SYSTEM FOR SPACE SHIPS WITH NUCLEAR POWER SOURCE by Ernst Stuhlinger.
Most of the details are available elsewhere, largely due to Ron Miller’s “Dream Machines” compendium of fictional spacecraft. From the paper itself we get the following data:
The asterisk denotes quantities I’ve derived. The payload, which includes the landing vehicle and crew habitat, is 20.5% of the launch mass, which is quite impressive. However the acceleration is very low, albeit optimized for the trajectory chosen. These days we wouldn’t want a crewed vehicle spending weeks crawling through the Van Allen Belts, but back when Stuhlinger computed his trajectory and even when the design aired, the Belts were utterly unknown. Now we’d have to throw in a solar radiation “storm shelter” and I’d feel rather uncomfortable making astronauts spend two years soaking up cosmic-rays in interplanetary space. Even so, the elegance of the design, as compared with the gargantuan Von Braun “Der Mars Projekt” for example, is a testament to Stuhlinger’s advocacy of electric propulsion.