Starship Hull Shape Analysis: Discuss the Reality of Sci-Fi

[Bab5space]

Using real science we can extrapolate what hull shapes could be used, assuming we actually did have high thrust constant acceleration drives (we don't because it requires energy/mass ratios that tend to cancel each other out).

So what shapes?

Pill capsules are ideal for crewed vessels. Even belly lander style. You could even put a sphere habitat inside it at the middle and rotate it so the crew feels 1g acceleration under thrust in space.

The curved outline of the hull is ideal at holding air pressure, which lends itself to crewed vessels.

Something blocky could also be used for crewed vessels, but to not put extra pressure on the hull, the inner hull would need to be cylinderal or spherical anyway. The outer blocky hull could just be armor since it surely is not optimal for pressurization.

We do not make blocky fuel tanks or gas tanks for a reason. Sharp corners would form stress cracks and leak sooner or later.

For vessels without internal pressurization or crew... the stargate Prometheus would work quite well.

Not the first nor the last time pop scifi was at odds with reality applied to s pace physics.

What do you think on this subject?

Discuss.

 

[GTOM]

I think my pirate ship should have a sharp nose to minimise impact angle of micrometeors. It can be opened to reveal the lasers.
Cylindrical fuel block. Cube like cargo block (no need for pressure)
And big radiator wings.

 

[Bab5space]

I think my pirate ship should have a sharp nose to minimise impact angle of micrometeors. It can be opened to reveal the lasers.
Cylindrical fuel block. Cube like cargo block (no need for pressure)
And big radiator wings.

Meteorites are the least of a pirate ship's problems. For the most part there is little reason for two warring spaceships to close within a few kilometers of one another, since missiles can kill at beyond that range and can cover kilometers in a matter of seconds in space.

And at those speeds unless pirate ship armor is fictionally tough, I doubt angling will make much difference due to the fact that IRL DPS increases dramatically with kinetic energy increasing.

I can understand the necessary conceit of scifi shields due to this.

As for radiators, they too are it seems... not up for the job assuming a starship wields or harnesses the tremendous energies required to pull off scifi FTL or warp.

The radiator size would scale so large that one would see the radiators... not your ship.

The little speck on the several kilometers,wide array of radiator wings would be the shipm

 

[member 656954]

Discuss.

LOL, what is this, LinkedIn!

But as with most answers in the sci-fi writing forum (and I'm concluding you are not writing a book, @Bab5space, because you ignore the question when asked), "it depends".

Atmospheric pressure can be contained in a non-spherical hull shape - the ISS includes some 'canister' shaped modules - but a tube is probably used more because it matches the shape of the lifting craft than it's the necessary shape for a pressurized habitat. Also, you can conceptually spin them to simulate gravity (they have to be large enough for this, and SpinCalc is good to calculate what radius works to minimize unwanted effects) in a way that is more convenient than a square shape.

In a non-hard sci-fi scenario, with AG thrown in, all bets are off and craft would most likely revert to a facsimile of Earth interior shapes - squarish with a floor, vertical walls, and ceiling. This then leads to blocky craft design, though the aerodynamic aspect for non-atmospheric ships is always amusing.

 

[Vanadium 50]

and I'm concluding you are not writing a book

Holy moly, I hope not! It would be all over the map!

This topic strikes me as odd:

"In the future, our technology will have advanced to the point where we can visit the stars! What shape could we make these starships?"
"Uh, if we are that advanced, can't we make them any shape we want? I mean we can practically do that today."
"That's completely unrealistic! Nobody will believe such crazy talk!"

 

[GTOM]

Holy moly, I hope not! It would be all over the map!

This topic strikes me as odd:

"In the future, our technology will have advanced to the point where we can visit the stars! What shape could we make these starships?"
"Uh, if we are that advanced, can't we make them any shape we want? I mean we can practically do that today."
"That's completely unrealistic! Nobody will believe such crazy talk!"

While contain 1 atm pressure isn't the main bottleneck, but if the ship attacked, it has to face bigger mechanical and heat stress.
Also i think nothing wrong with design match practicality.

 

[member 656954]

but if the ship attacked, it has to face bigger mechanical and heat stress.

You're adding a new parameter to your OP, but if they are under attack the shape probably does not make much difference. Kinetic energy strikes in the real world are going to punch through pretty much any material we can devise, and you can't maneuver much in space, and certainly not like we see in the movies, so dodging, ducking, or weaving is not really a practical tactic.

Also i think nothing wrong with design match practicality.

True, but unless you're writing a really hard sci-fi novel, most stories are going to be entirely unreal with regards spaceship design practicality.

(I'm re-reading one of Iain M. Banks Culture novels, Excession, and the ships are tens of kilometers long with HUGE inner spaces and interior surfaces that move about as needed. Do I believe this is possible? Not really. Do I care that it isn't? Nope. His imagination, expressed so eloquently, evaporates any such concerns and I just enjoy the ride.)

 

[Bab5space]

While contain 1 atm pressure isn't the main bottleneck, but if the ship attacked, it has to face bigger mechanical and heat stress.
Also i think nothing wrong with design match practicality.

You're adding a new parameter to your OP, but if they are under attack the shape probably does not make much difference. Kinetic energy strikes in the real world are going to punch through pretty much any material we can devise, and you can't maneuver much in space, and certainly not like we see in the movies, so dodging, ducking, or weaving is not really a practical tactic.
True, but unless you're writing a really hard sci-fi novel, most stories are going to be entirely unreal with regards spaceship design practicality.

(I'm re-reading one of Iain M. Banks Culture novels, Excession, and the ships are tens of kilometers long with HUGE inner spaces and interior surfaces that move about as needed. Do I believe this is possible? Not really. Do I care that it isn't? Nope. His imagination, expressed so eloquently, evaporates any such concerns and I just enjoy the ride.)

GTOM that's more or less why I think outside the fictional box and use reality where it is not story-breaking.

Certain concepts really are story breaking if we follow reality, but I temd to always compensate somehow. Examples:

How do starships deal with meeting mass/energy ratios that would properly kill anything we can currently design?

Energy to matter conversion fields, so if soneone fires a terawatt laser beam at your starship, it is converted into a stream of atomic particles as it hits the shield while being simultaneously deflected at the same time. The whole process happens so fast all one see's is a flash where the laser hits.

The same method would be used for waste heat, and the power source could be something as mundane in scifi as hyperspace... because reality as we understand it would not allow it anyway.

 

[Vanadium 50]

You're adding a new parameter to your OP,

This happens a lot with this OP. "Guess what I am thinking of!" is not a fun game.

Fictional starships don't have to look like anything. Timothy Zahn's Quadrail looks like a train. Because it's a train. The FTL physics is no crazier than anything else and it's better than most. It's also described just well enough to advance the plot.

And there are no pirates.

 

[GTOM]

Pirates have an important role in my story although ransoming is more common than actual boarding actions, which needs special circumstances (close flight paths)

 

[essenmein]

In my story ship design follows function, and function is simple. Carry a gun big enough to destroy the enemy.

I just love the story of how the A10 warthog came into existence, here is the gun, the GAU-8, now make it fly.