On Friday I began a discussion of how to apply the Moonbase hybrid-inflatable design.
I took the opportunity to draw a quick diagram to visualise what I was trying to describe. Access it from the Space section of my website. Please take a look.
As I mentioned on Friday, placing a floor inside a Moonbagel a third of the way up its diameter maximises usable floorspace, and this diagram illustrates the concept quite well. To me, the positioning looks like the optimal configuration for such a small module; in a larger module, I would put two floors in, at a third and at two thirds of the way up inside.
By now you've no doubt noticed the caption: "Moonbagel/Space Shuttle". That's because I chose the dimensions for this example quite carefully to fit into the Space Shuttle's main bay: the module as shown would fit into exactly a quarter of the bay, uninflated (the dashed outline).
I tackled another problem with this sketch. The bulkiest part of a module is the central core, which must contain hardware (wet & environmental systems) and the envelope, when uninflated. The original sketches show the core being held above a vacuum space by the pressure in the inflatable section. I don't like that configuration, because it would impose unnecessary stresses on the points where the ring meets the core. As shown, I've chosen a configuration where the base of the core is on a level with the base of the ring, and rests on the same surface.
Those are the main points I tried to fit into the diagram. Once I'd drawn it problems with it started appearing to me: I'm forever self-analysing. For instance, where should an airlock go? In this design, I can't find a suitable place to fit one. And where could the flooring be stored while in transit? Where could power cables connect to the module? The expansion coefficient isn't as big as it could be, either. However, I can't see a module much larger than this in its uninflated form being practical to move around on the Moon.