May 272013
The concept of an orbital fuel depot, supplied from Earth in order to fuel missions to Mars and the like, is not especially new. Shown below is a concept from General Dyanamics from 1963, depicting a toroidal propellant depot. A torus is a rather poor shape for such a thing… not only is it heavier than an equivalent-mass spherical tank, it also has substantially more surface area. But the advantage of this configuration is that it would easily pack in excess payload space aboard a partially-loaded Nova launch vehicle. Dimensions weren’t given, but maximum diameter would be less than 70 feet.
toroidal tank shape make on first look no sense
but it has some advantage.
i think that this fuel depot, is launch as secondary payload with Nova
and that docking spacecraft simply use the center opening of toroidal tank
also i note that the toroidal tank show sidewise to sun (see solar collector)
so expose only small surface section to sun