But space is pretty big, why would you expect to need high acceleration? Since you have to apply more or less equivalent braking force, you might as well get up to speed gradually, then slow down gradually. It is going to take a long time, one way or the other, but reducing the stresses of high acceleration will probably be better for your ship and its wetware.
I am going to go for modular. Cylindrical components that fit together lego-wise.
It is quite possible that any interplanetary manned missions will have ships constructed on earth, assembled and fueled in space and launched from there. The ISS and MIR were both like this with docking stations used for all supply needs. I can’t see why the same wouldn’t apply if we ventured further out.
Interstellar – well that’s a whole 'nother thing. I just don’t see that happening.
It depends on how you apply the force. If you’re thinking of the ship being pushed by a rocket, you need some bulk to hold the thing together. If you think of a structure being pulled by a tether behind the engine component, it can be a lot less bulky since the structure is held together by tension.
Try this site. If you’re interested in hypothetical space warfare, then I highly suggest the page on space weapons.
Several good suggestions so far -
Cylindrical combines ease of manufacture with pressure containment.
Multiple cylinders means redundancy if ther is a breach - somewhere to hide while you fix the problem.
If we assume some low thrust system - like an ion engine, slow thrust, longer duration - the craft has to “balance” on the engine thrust. There will be a certain amount of ability to steer the craft, but if you have, say, 3 engines widely spaced tehe’s the danger of throwing your craft off course if one engine fails; so the main thrust will be concentrated in a central point.
You can have antennae on long booms, etc. but they have to stand up to whatever maneuvering the ship will do; plus, long fragile things are points of vulnerability - anything from collisions with other craft to hitting debris. Long and thing sounds safest.
the most significant, visible part of the ISS is the huge solar panels. It’s free energy, but perhaps too fragile to leave extended during maneuvers. Also, beyond Mars the solar power drops off quite a bit. So it depends on the mission profile of your craft. if it is a behemoth with fusion engines, it will look different than a 2050 earth-to-mars orbiter using chemical and ion engines.
I’m having trouble imagining an asymmetrical airplane…wouldn’t that be inherently unstable?
Not necessarily.
Ok, cool…see, I was assuming asymmetric weight distribution etc., not just appearance. Why I’m not an engineer, right?
Interesting to note that the first aircraft had some instability that had to be compensated for, but the second was actually designed to remain stable in the event of the loss of one engine.
Thanks for the links.
Robert Goddard’s first rockets had the engine at the top, the fuel tanks and payload in the back-would such a configuration make sense for an interstellar ship?
Looks are certainly one aspect of design, and anybody looking to build a space ship is going to look at competing designs. A cool looking design could give the impression of being more complete, better thought out or modern. At some point somebody is going to be writing a big check and all else being equal, they might prefer the ‘cool looking’ one.
The ISV Venture Star–the interstellar ship in Avatar–is one of the more plausible interstellar ship designs, and the radiator fins (glowing red) are a prominent part of the design.
Another asymmetric concept is the Oblique Wing. One reason this makes sense is that the trailing end of the wing creates a drag vortex: eliminate one of these and your efficiency goes up. The downside is that the powerplant has to be fuselage-mounted (noisier for passengers) and the wing becomes a little less practical for fuel storage.
Assuming constant accel/decel, you’d still want the highest acceleration/deceleration you could manage given all design points (including wetware), to reduce transit time. 1G is “high acceleration” compared to microgravity.
Whether compressile or tensile strenth is required, catenary arches are ideal since they minimize the transverse forces. (A catenary is the shape an infinitely flexible chain falls into when suspeneded at its ends.)
So, to explore ideal architectures assuming significant acceleration, look at buildings designed by Gaudi. 
I would assume spherical due to the efficiency of the shape with respect to handling pressure differentials…OTOH, should the shape have to deal with friction, either atmospheric or other environmental particles, especially at high impact speeds, there might be a bias towards a minimized profile facing the direction of movement.
What you really want is a shape-shifting craft. 
People have to look at bridges and skyscrapers every day. Governments are loathe to approve the building of eyesores that will be standing for 75 years. Out in space, you have very little opportunity to leave the ship and admire the paint job.
If we’re talking passenger ship, clean flowing symmetry is going to portray a sense of security and quality. People like that, and you need to have a ship people like.
If we’re talking a working ship, one that mines asteroids, or transports goods between stations, it’s going to have the high style of a UPS truck.
The best starship is a hollowed-out asteroid. Radiation shielding from hundreds of feet of rock is great, and you can rotate it to provide the travelers with gravity.
Since this ship is going to take hundreds of to reach its destination, you need enough resources such that generations of astronauts can live in it.
Plus, the mass is needed to absorb the shock of the nuclear bomb explosions needed to propel the ship.
Form follows function. We can’t say with any certainty what a future spaceship or starship will look like, because there will be design considerations, technological advances and mission requirements that we can’t predict.
I wonder if cube designs will ever catch on: http://www.startrek.com/legacy_media/images/200508/tng-142-j25-borg-cube/320x240.jpg
I think the best, and most practical, design are the city shaped spaceships used by the government (Alliance?) in Firefly. They had skyscrapers and everything. Sorry, I couldn’t find an image to link to.
Bob
Unless the power is incredibly cheap, the overriding factor will be minimizing weight. Unncessary decoration or structure for “aesthtics” will be dropped in favour of simplicity and low weight - if you don’t need it, don’t bolt it on. If all you need is a reinforcing strut, it does not need an aerodynamic outer shell. The only conceivable reason for a pretty “Shell” would be side protection from meteors.
Look at the functional but ugly lunar lander - nowhere near aerodynamic. I think long and thin to minimize the cross-section and risk from oncoming debris, the most likely direction; I would conceive of a “meteor shield” up front that is basically a foamed aluminum lump where the foam is filled with something like hydrogen or xenon to provide maximum stopping power while weighing as little as possible. Another suggestion was that the fuel be stored as ice in a shield up front of the ship too.