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How would a spaceship made in space and for space only look like?


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Let's say that asteroid mining gets big and it's gold rush all over again. Lots of people, individuals and corporations, set out to make a fortune in the asteroid belt. People live there and work there for a significant amount of time. They need vehicles to get from place to place. And it's cheaper to make spaceships using materials mined from asteroids. Assuming the technology used in making it is not too far from today's technology, how would such spaceship look like?

 

(And please don't say "it's all going to be automated anyway so why do you need people working in space.")

Edited by Algiark
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Probably like a hybride of Mir and Nautilus-X but with solar panels on long ISS/Mir2-like cross trusses.
Modules built on the Earth to be docked to the base. Of course, rigid, not inflatable.
The base module probably in size of Skylab, 6.5 m. Others probably in common railway-derived size 4.2-4.5 m.
The smallest modules - like Almaz/MOL 3 m cylinders (because of 2x2 m corridor/cubicle inside: exactly to place a Vitruvian human).
Originally probably with different sticks and boxes around all over the body and with a rusty pick-up behind the barn.  Then covered with veils and shrouds to protect from the dust and rays and increase lifespan.

Edited by kerbiloid
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Also have a look at the plans for NASA's Orion MTV:

Orion_docked_to_Mars_Transfer_Vehicle.jp

With the exception of the small return pods docked on the front and side, the Orion MTV is designed to be assembled in space (albeit from parts fabricated on Earth) and remain in space for the duration of its service life.

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It's probably going to look much like the Apollo Lunar Lander - angular, unaerodynamic crafts build out of metal sheets just thick enough to hold a breathable atmosphere. That, or inflatable crew modules fitted on trusses with parts like cargo containers, propellant tanks, and other miscellanea bolted on.

Lunar_Module_diagram.jpg

 

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Depending on the asteroid composition and size (a 'rubble pile' asteroid probably wouldn't be much good), the 'roid itself could be the outer hull of your ship. Dig a hole at one end for a nuclear reactor, dig out more holes at the other end for living space, spray some polymer sealant over the inside for added airtightness if needed, hang some thrusters off it somewhere and presto - one luxury rock-et ship.

 

 

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I think maybe the first question to ask is "what is the easiest thing to make in space?" Going from raw materials to vehicles is quite the operation. Each step would need to be carefully considered. Honestly, a good place to look would be the Rouge River industrial complex which was designed to go from raw materials like soda lime and iron ore to cars. Everything to build cars was done there except acquiring raw materials. Steel mills, foundries, machine shops, assembly line all of that was in one spot. I would assume that space manufacturing would be somewhat similar where everything would be in one spot. So then the next question is that for each one of those parts of the manufacturing chain, what is the best way of doing it? Do you grab an asteroid whole and melt it down?

How do you melt it down? They already use electric arc furnaces in steel mills and foundries so that might not be a bad idea.

How do you purify the ore? Normally, once it is liquid any gas would bubble out but it doesn't work like that in zero g. Hypothetically you could centrifuge it but that would be a pretty huge centrifuge.

After melting down ore and purifying it into usable alloys, how do you produce the next rough shapes? 3D printing seems like a cool way of doing it but it is an incredibly slow process. Do you make structural shapes like I beams, tubes, and flat sheets? These are things that engineers are already used to working with.

How are they assembled? Bolting and riveting could be done like current spacecraft. Are the fasteners made in onsite as well? Electric arc welding could be beneficial. Hypothetically in space you wouldn't need shield gas so that seems promising.

There are many questions to answer about in orbit raw material to finished product manufacturing that need to be answered. To me, they are all interesting and exciting because no one has ever done it before but that doesn't mean that there aren't analogs here on the ground. As for what spacecraft would look like, they would likely be a product of "whatever is easiest" along each step of the process.

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13 hours ago, Racescort666 said:

Do you make structural shapes like I beams, tubes, and flat sheets? These are things that engineers are already used to working with.

That would actually be a really interesting question. What sort of structural shapes would be optimal when you don't have to contend with gravity? Anyone any good at finite element analysis? :)

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Any KSP player will tell you that you'd want a spaceship to be :

- light (the lesser dry mass, the better)
- not wobbling

Carrying human add a few requirements :
- Efficient shielding
- Artificial gravity would be good

Ferrying goods :
- normalized containers


I'm no space engineer (except in KSP), but spherical tanks seems obvious : best volume/surface. May not apply for high pressure content.
You'd probably want your containers to be assembled in a compact way, forming a stiff structure. So hexagonal-based containers fitting in honeycomb bays could be used.

Main structure would be beam and struts (can be made light and rigid)

Smaller ship would have living quarters surrounded by 6 containers lines, so that containers provide shielding.

For bigger ships, you'd probably want artificial gravity. Easiest way to rotate the structure is to have two parts with tethers in-between : one main cargo + engines, the other with living space. When cruising, you'd rotate the whole structure. When thrusting, you'd have to kill rotation first, and shorten the tethers to bring the two parts together. Engines would be positioned on the sides, so that no exhaust can damage any part of the ship when in "compact" mode.

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It depends a fair bit on just what sort of ship it is. Any sort of electric propulsion, you're gonna need giant radiators. Nuclear propulsion, electric or otherwise, you're well served by having a long spine to put the radiation source further from the sensitive bits. Want to aerobrake on return to Earth or wherever you're going? Something like SpaceX's ITS. (This sort of thing can also be open-topped, sort of like a partial shell around your ship, look up NASA's ellipsled)

There's a ton of different designs on Project Rho, including a ship specifically designed to transport crew and cargo to and from the asteroid belt.

http://www.projectrho.com/public_html/rocket/realdesigns.php

Edited by Elukka
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A sphere is best for this. For each containing thing anyway. Spheres don't need to be aerodynamic and they aren't. You get the most volume for your surface area, and you get the least surface area for your volume, and spheres hold in pressure the best. I envision a big spherical fuel tank with a smaller sphere or a torus in front for habitation. And the engine on the back. If it's supposed to be able to aerobrake then it gets a little different. I'd put the habitation behind the fuel, and the engine somehow behind the habitation. On struts with a hose feeding fuel and oxidizer to it or something.

Bottom line is, they'll probably be ugly.

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lots of exterior structure. a lot of space craft designs seem to have exterior panels and i think thats kind of backwards. if you have a pressure hull its better to have your skin inside the structural bits since the pressure forces are pushing outward rather than inward. this applies to both fuel tanks and habitable spaces.

spherical pressure hulls are certainly desired. i also imagine double hull spacecraft with an outer fuel hull and an inner habitation hull. you can use fuel as radiation shielding.

on ships with reactors you might see a long boom with a reactor module at the end, this geometry allows for less shielding to be used and provides a good safety margin for the crew. think event horizon.

 

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14 hours ago, Findthepin1 said:

A sphere is best for this. For each containing thing anyway. Spheres don't need to be aerodynamic and they aren't. You get the most volume for your surface area, and you get the least surface area for your volume, and spheres hold in pressure the best. I envision a big spherical fuel tank with a smaller sphere or a torus in front for habitation. And the engine on the back. If it's supposed to be able to aerobrake then it gets a little different. I'd put the habitation behind the fuel, and the engine somehow behind the habitation. On struts with a hose feeding fuel and oxidizer to it or something.

Bottom line is, they'll probably be ugly.

The problem with spheres is cost. This can be reduced thanks to super technology in the far future.

Also, in some cases you want to maximize area (solar panels, radiators).

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horizontal_pour_1.jpg

I've spent some more time thinking about this and I think cylindrical structure would be a good way to go. Centrifugal casting is already a pretty common process and could be easily scaled up. Ships could end up looking like the ones from Children of a Dead Earth. Basically big unexciting tubes.

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22 minutes ago, Racescort666 said:

horizontal_pour_1.jpg

I've spent some more time thinking about this and I think cylindrical structure would be a good way to go. Centrifugal casting is already a pretty common process and could be easily scaled up. Ships could end up looking like the ones from Children of a Dead Earth. Basically big unexciting tubes.

Easily scaled up?

You mean to somehow cast a huge structure as a single part? Not easy at all. To start you'll need a mold bigger than the final part, and it presumably needs to be reusable. Your illustration shows gravity as a thing. Why is the metal flowing into the mold in microgravity? If you spin the whole foundry (to get a gradient for the molten metal), then the resultant part will likely show signs of that preferred direction. 

 

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On 11/11/2016 at 1:02 AM, KSK said:

That would actually be a really interesting question. What sort of structural shapes would be optimal when you don't have to contend with gravity? Anyone any good at finite element analysis? :)

For space construction, you want lightweight rigid structural elements that can be mass produced and then fit together like tinkertoys to create the framework for whatever you want to attach to it. Such as:

7dd703b0ceea81079f8cea451295f34f.jpg

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