posted on Jan, 19 2009 @ 10:45 PM
I think just about any spacecraft design is viable, depending on the technology.
As to Human-designed automobiles....we've some that defy the 'four-wheel' planform. AND, if you compare, say a Prius to an
eighteen-wheeler....well, since you Humans are already familiar, of COURSE you recognize them as some-what kindred forms of surface transport.
Then, one can consider variatons on the locomotive and the train cars, all with specific roles, designed for specific functions.
Lighter-than-air craft (dirigibles, or 'blimps'). Sailplanes (gliders) versus piston airplanes and jet airplanes...the 'flying-wing' B-2 bomber.
Even passenger jet configurations vary, although most more modern designs are sticking to the 'under-the-wing engine location designs, as opposed to
tail-mounted engines.
ALL of these various designs, which each providing a specific role, are nonetheless designed by ONE species....us!
SO, if one will allow, for a moment, the mere possiblity of more than one intelligent species with FTL travel, within our Galaxy...then the variety of
craft could prove to be quite large.