Starship hulls, an idea or two

[Swank]

I'd assume if they went with the overlaid method, it would make it easier to replace damaged sections or even perform maintenance.

As for viewports, I think it depends on which method the writers come up with. Trek apparently uses transparent aluminium but they never go into detail about how it's installed and the actual windows on the Enterprise D don't really show off many clues there either. And those things look about 2 meters long in some cases!

I'm not sure if transparent metals are a thing in real life though.

Aluminium oxynitride - Wikipedia

en.wikipedia.org

But what do you need uncovered windows for? Subs don't have them. Cameras are easy to protect and replace.

 

[Swank]

BTW, a product you can make in space, which would have many excellent properties at a weight savings, is foam steel. Essentially, cast steel full of inert gas bubbles. (Or maybe nitrogen if you are able to control using it in a nitrogen hardening alloy.)

You can also get away with making things like steel reinforced aluminum (the moon is largely aluminum) in a metal matrix.

 

[Wayne Mack]

For military concerns, I kind of like @Venusian Broon's idea of using ice or perhaps water. I can see building an outer perimeter of ice or water housed between some membrane. I can see three aspects to protect against: impact, thermal, and radiation.

For impact, one wants to redirect the force from direct on to radially outwards. This is essentially how a bulletproof vest works. Imagine a layer of ice-filled balloons just beyond the surface of the ship's hull. I'm not sure of the coupling force between these balloons, but they could dissipate energy form any sort of collision. I do wonder about use of ice versus water, as ice would require some means of maintaining a low enough temperature and bleeding heat. Water, though, could be maintained at a liquid state by having a fixed volume for the container.

Water works for thermal dissipation as well. The temperature difference between ice and water probably doesn't matter for military level attacks. There would be a need of some mechanism to seal holes after a thermal attack, though, so as not to open a vulnerability.

Water also provides dampening against radiation, though this can be augmented with a metal hull inside the external layer of water bubble wrap.

The remaining challenge would be how to harden the engines against attack. I assume that the shielding would need an opening to allow for propulsion.

 

[THX1138]

I was just about to suggest Foamed Steal @Swank!
Also, angling the front of the haul to say, 30deg, would also increase the horizontal thickness of the haul too. So, a half meter think bulkhead set at 30deg would become 1 meter or so along the horizontal.

So, using an angled Foam Steal haul with the ice up front would give a multi-layer protection and you could reduce the weight even further if your haul was 250cm of Foam Steal at 30deg. (500cm equivalent +-)

Being Foam Steal, 100cm thick would be more than enough I would think.

 

[hitmouse]

A couple of people have mentioned radiation shielding. This is an interesting subject.

A magnetic field of some description, which could possibly be designed to be much larger than the vessel, is a good way to protect against charged particles, but would have no effect on high energy photons(x-rays). Charged particles are also generally absorbed by a fairly modest solid barrier.
High energy x-rays are the real problem: the question is how high a dose is likely in deep space and what kind of construction is proportionate. Practical safety in this setting depends on attenuation rather than total elimination: this is a product of density and thickness. For example, in a therapeutic linear accelerator bunker in a radiotherapy department (x-rays up to about 15 mV, much less than some cosmic radiation) the walls are 2-3m thick high density concrete in order to attenuate any penetrating radiation to publicly acceptable levels. It is possible to build bunkers of so-called leadite bricks with walls a couple of feet thick. The problem is that however you cut it, radiation sheilding is very heavy.