Sol's Shipbuilding Industry

[Corvus 501]

This is just some ideas that I had about industrial scale shipbuilding in the Sol system. Questions, comments, and ideas?
1. Some raw materials (iron, nickel, copper, titanium, molybdenum, tungsten, beryllium, aluminum, boron, graphite, carbon silica, and silicon) come from the Belt, others from the Oort cloud (water, water components like o2 and hydrogen, and deuterium). Still others come from Titan, things like methane, ethane, and many other hydrocarbons.
2. From there, the non-metallic elements and molecules are shipped to orbital factories over Mars for processing, than to Earth's L5 point. Metals (and some other materials) go to some mirror array factories in orbit of the sun for processing of their own. Afterwords, they are boosted using laser launch ion drive freighters to bring them to the L5 shipyards.
3. These components are than combined with finished products from Earth, Luna, and Mars, and assembled into everything from garbage scows, ore freighters, and merchant freighters, to warp capable warships and parasite craft like shuttles and fighters.

[NecronLord]

Welcome to the board. Please use less smilies.

Anyways, why is it necessarily more cost effective to get water from the Oort cloud than from Earth? Water's abundant in space, yes, but Earth is very close. This is really an engineering problem so it depends on what kind of machines you're building, what is the most efficient approach; ostensibly moving a comet is one of the easiest ways to get water, but it's not always going to be the fastest or most practical.

[Iroscato]

What is this, exactly? An idea for world-building for a novel? Your predictions on what shipbuilding will be like in the future? Rambling, incoherent rantings of a drunken/baked madman?

[Sea Skimmer]

Sounds like you have far more interplanetary transport then is necessary, why build anything at earth if resources are coming from as far as the Oort cloud? Even if certain equipment is made on earth or the moon, it would be easier to ship that stuff out then bring in the bulk mass of hull material.

[Corvus 501]

Basically, it's simpler to build things where industry already exists, like what would exist on Luna, Mars, and Terra, and raw materials come from their areas of origin, but factories should be in a centralized area, or at least the shipyards should be. This is mostly for commuting and protection purposes.

[Corvus 501]

The system that I outlined is concurrent with what I know about the factory system, and this is my attempt to adapt it to space. It's just a thought experiment for now, but if anyone thinks that this is worth writing about, I encourage them to, seeing that I really don't have the patience to write it, and would love to read any story that results from this idea.

[biostem]

Depending upon just how advanced space travel is, setting up something on one of Jupiter's small rocky moons might be ideal - you could get all the water you need from that one icy moon, all the methane or w/e from that other one, and so on. If space travel wouldn't permit casual travel between said moons, then perhaps a base on Earth's moon could work - last I read there was ice in the polar craters, and you should be able to process the moon rocks for ore and so forth.

[Corvus 501]

The idea is that the ships are built in a centralized, protected area in a zero g envirement, ant the Earth-Moon L5 point is ideal, because that's where the gravaty of the Earth and Luna are balanced, meaning that verry little effort is needed for station keeping. As for why build in that L5 point, well, the indrustry is already there, or products produced by thoes indrustries can be brought to the shipyards, as can workers.

[Simon_Jester]

The main issue here is that it takes considerable expenditure of energy to lower a billion tons of rocks into Earth's gravity well, then hoist them back out again in the form of processed ship or throwaway slag.

[What, you say, you're not planning to remove the slag? This results in a very, very big pile of mine tailings floating in Earth orbit, which may or may not be a problem]

Therefore, at some point not too far into this process someone is going to notice that it's probably less work in energy terms to move the factory once than to move each shipment of raw materials. The factory will be relocated to minimize transport costs as far as practical.

If the available space transport technology does not allow this, then moving shipments of ore or water across the solar system won't be very practical either.

[Corvus 501]

The shipyard isn't on Earth, it's at the Earth/Moon L5 point, and the forges are in orbit of the sun. the slag can be stored and sold, or, if no one is buying, than it can be dumpted into the Sun.

[Simon_Jester]

...

You DO realize that dumping things into the sun takes a massive investment of delta-v, right? Anything in a more or less circular solar orbit at the Earth's orbital radius, including the Lagrange points, is moving. Moving at roughly thirty kilometers a second sideways relative to the sun, as per the definition of "solar orbit."

So to "dump it into the sun," you can't just somehow shove it out the back of a dump spacetruck and let gravity take its course. You have to use some sort of retro-rocket burn to decelerate the material, cancel virtually all of its orbital velocity, and let it go. You have to take all that stuff and perform the equivalent of accelerating it to 30 km/s relative to the Earth.

And you DO have to cancel all of it, not just a little; otherwise the millions of tons of rocks will enter an elliptical orbit about the sun, with the aphelion at... pretty much wherever you dumped them from. In which case, thanks to Kepler's Third Law, we've now got a cloud of interplanetary buckshot which will come zooming through the general vicinity of Earth once a year, every year, as the anniversary of your stupidity.

I can't think of anything more pointlessly wasteful than taking huge chunks of useless, heavy matter (like a pile of mine tailings) and deliberately accelerating them so they fall into the sun. It might make sense to do this with relatively low-mass objects that you MUST make sure you visibly dispose of (say, radioactive waste, or hazardous biological materials), but that's a very different story.
___________________________

Moreover, while putting the shipyards at the L5 point reduces the gravity well problem, it's still there: it still takes a lot of unnecessary delta-v to carry an asteroid to the L5 point compared to, say, moving the same asteroid to a shipyard located on Ceres. Moreover, moving whole asteroids and comets is a slow procedure, because of their great weight you have to nudge them gently and let them coast a long time. For business purposes it's much better to NOT have a time delay of years between the time you set the supplies in motion and the time they arrive.

And the last point to consider involving the Lagrange points is that they're so easy to hang around in that they're cluttered. It's not just you who will be occupying that real estate, it's all the drifting rocks and sand floating around in space. The Lagrange points become attractors for all sorts of miscellaneous dust and gravel; the maintenance cost of keeping your factory running while being hit by a constant stream of micrometeorites is an issue.

[Borgholio]

As an example of what makes sense, look at the movie "Alien". The movie is set on a small "tugboat" freighter towing an entire refinery and mining station between Earth and a location in another solar system. They basically haul the mining rig out there, mine, process, refine, and store the output, then tow the whole thing back to Earth and profit. Within our own solar system, it would only take weeks / months to move a prefabricated factory to the mining location where it can stay for years without worrying about slinging asteroids towards something squishy...like Earth.

[Corvus 501]

To Simon_Jester First, whole astaroids are not towed out, just semi-refined (or unrefined) ore in ore freghters. Second, the solar smelters are mirror arays in orbit of the sun. Power is therefor cheap. Third, like the freghters designed to take metals from the forge, the slag ships use laser powered silaca ion drives. It's just using garbage (and a little enegry) to get rid of garbage. I'm sorry if I was not clear on this matter.

[Corvus 501]

Furthurmore, the cometary matiral is not just used fo provide atmosphere for the ships and reaction mass for the ships, but is used to fuel the (extremly fast) plasma drives of the ore freghters outbound from the Belt.

[Terralthra]

...
And you DO have to cancel all of it, not just a little; otherwise the millions of tons of rocks will enter an elliptical orbit about the sun, with the aphelion at... pretty much wherever you dumped them from. In which case, thanks to Kepler's Third Law, we've now got a cloud of interplanetary buckshot which will come zooming through the general vicinity of Earth once a year, every year, as the anniversary of your stupidity.

emphasis mine

I love you.

I'm curious what "mine tailings" even means in space. Once you're outside a well, and moved into a relatively unoccupied orbit, structures can be made out of fairly weak materials so long as they have the ability to be repaired from micrometeorite impacts.

[Corvus 501]

The forges arn't in orbit of the Earth, they share an orbit with Mercury.

[Terralthra]

The forges arn't in orbit of the Earth, they share an orbit with Mercury.

That just compounds the problem. Unless lots of people are living in orbits near Mercury (unlikely), you now have to spend even MORE delta-v moving your desired ores and forge products back out to an orbit where people live and work. Also, who's running these forges? How are you keeping them habitable? The orbit of Mercury is really really hot[citation needed], and it's going to be a rather large engineering challenge to get people living there to run the forge (and also to temper metals, which requires you cool them down, in addition to heating them up).

[Corvus 501]

Also, the slag ships would use a flyout system to reach a safe distence from the forges, or in other words, they leave ouner low velocity, and THEN accelerate into the Sun.

[Corvus 501]

To Sith Devote: good points all, but the delta-v problem solves itself. The purpolsion system of the outbound forged metel freghters is a laser powered ion drive, one which uses ionised silaca gas as reaction mass. It's bascialy a cross between a solar powered ion drive, and a laser launch rocket system.
As to your piont about coolin the metel down, why don't you pitch your own idea? Mine is to spray it with gas liberated from cometary matiral, but I could use some new ideas there .

[GrandMasterTerwynn]

Also, the slag ships would use a flyout system to reach a safe distence from the forges, or in other words, they leave ouner low velocity, and THEN accelerate into the Sun.

Why are you so insistent on the idea of throwing slag into the Sun? For that matter, why locate your forges that close to the Sun in the first place? If you're using giant mirrors to melt down asteroids, it'd be simpler to to just use bigger mirrors. Or solar collectors close to the Sun beaming power to the smelters via huge lasers. Altough, if you insist on keeping your smelters near the bottom of the Sun's gravity well, your "slag" can be used to solve the problem of keeping the parts of the industry cool that you need to keep cool. You could build a sunshade and a lot of insulation using your asteroid mining waste products.

[Terralthra]

Also, the slag ships would use a flyout system to reach a safe distence from the forges, or in other words, they leave ouner low velocity, and THEN accelerate into the Sun.

Why are you so insistent on the idea of throwing slag into the Sun? For that matter, why locate your forges that close to the Sun in the first place? If you're using giant mirrors to melt down asteroids, it'd be simpler to to just use bigger mirrors. Or solar collectors close to the Sun beaming power to the smelters via huge lasers. Altough, if you insist on keeping your smelters near the bottom of the Sun's gravity well, your "slag" can be used to solve the problem of keeping the parts of the industry cool that you need to keep cool. You could build a sunshade and a lot of insulation using your asteroid mining waste products.

That would work a bit, but I'm not sure that'd work all that well. Anything close enough to Sol to shade a Mercury-distance orbiting forge is also going to be hot as balls - several hundred degrees K, enough to start radiating heat of its own. It'd have to be near-planet-sized itself to have enough thermal mass to have any significant insulation on the dark side.

[GrandMasterTerwynn]

Also, the slag ships would use a flyout system to reach a safe distence from the forges, or in other words, they leave ouner low velocity, and THEN accelerate into the Sun.

Why are you so insistent on the idea of throwing slag into the Sun? For that matter, why locate your forges that close to the Sun in the first place? If you're using giant mirrors to melt down asteroids, it'd be simpler to to just use bigger mirrors. Or solar collectors close to the Sun beaming power to the smelters via huge lasers. Altough, if you insist on keeping your smelters near the bottom of the Sun's gravity well, your "slag" can be used to solve the problem of keeping the parts of the industry cool that you need to keep cool. You could build a sunshade and a lot of insulation using your asteroid mining waste products.

That would work a bit, but I'm not sure that'd work all that well. Anything close enough to Sol to shade a Mercury-distance orbiting forge is also going to be hot as balls - several hundred degrees K, enough to start radiating heat of its own. It'd have to be near-planet-sized itself to have enough thermal mass to have any significant insulation on the dark side.

Presumably, you could make the Sol-facing side a mirror, which would cut down on the insolation of the sunshade by quite a bit. Granted, the other side of the shade would get quite warm, since there's no way that I know of to create a 100% reflective mirror, but the radiant heat of the sunshade might be easier to cope with than full-on sunshine.

[Corvus 501]

Good idea, but what I was thinking of was a open set of mirrors that reflect sunlight onto the target mass of ore, instead of the usual setup that a Earthbound forge.

[Corvus 501]

To Sith Acolyte: as for my insistence on throwing stuff into the sun, well, some people see it as the thing that heats the Earth, but I see it as the Solar System's biggest incinerator. What could be cooler?

[Batman]

Throwing stuff into the sun works splendidly in soft sci-fi scenarios where you can casually accelerate so fast you need to actually compensate for that or watch your crew go splat. You seem to be going for a halfway realistic setup, where all the mentioned problems DO apply, And Sith Acolyte has yet to post in this thread?