Off world built spaceships

[Spacescifi]

It dawned on me that another use for exoplanetary resources is builiding new spaceships.

While we are not anywhere near this, in a far future setting it could be possible.

So my question is, what sort of spaceship hulls would you get from...

 

Asteroids? The moon? Mars? Mercury?

The moon I can partially answer, alluminum.

I also know that some resources must be imported from earth to do the refining and processing, as I do not know of any other world that has ALL the chemicals/resources required for ore to metal processing. Nonetheless, the ore will definitely be exoplanet or asteroid ore.

What planets would provide the strongest hull materials? Those with 2g or higher. Problem then becomes getting the stuff off the planet. It's like for really awesome stuff you need to have better tech to even access it. It also means that super advanced spaceships of the future that CAN mine ore from 2g or higher worlds could have hulls far stronger than modern hulls using materials from earth.

 

Your thoughts?

Edited September 6, 2019 by Spacescifi

[wumpus]

Asteroid steel seems the most obvious, although if you have enough time and solar power, lunar aluminum would make sense.

I'd assume that for a long time, off world hull construction would be for spaceships were shielding is far more important than mass, so hollowing out an asteroid would make a lot of sense.

"Those with 2g or higher." Sorry, chemistry doesn't care a hoot about gravity.  Forging might  be easier under some considerations (although probably not others), but you really don't want to build you hull in Earth's gravity well, let alone something with a 2g acceleration.  Space construction will be done in zero-g until energy (and lifting into orbit) is essentially free.

[Spacescifi]

3 hours ago, wumpus said:

Asteroid steel seems the most obvious, although if you have enough time and solar power, lunar aluminum would make sense.

I'd assume that for a long time, off world hull construction would be for spaceships were shielding is far more important than mass, so hollowing out an asteroid would make a lot of sense.

"Those with 2g or higher." Sorry, chemistry doesn't care a hoot about gravity.  Forging might  be easier under some considerations (although probably not others), but you really don't want to build you hull in Earth's gravity well, let alone something with a 2g acceleration.  Space construction will be done in zero-g until energy (and lifting into orbit) is essentially free.

 

You misunderstand my point.

 

The resources on a 2g, 3g, or 4g world are NOT the same as on a 1g world.

Some resources under great pressure can exist in states we do not naturally have on Earth.

Granted, you may have to dig for metallic gases, but I rest my case.

That rests heavily on whether or not they stay metallic without the pressure.

 

Mine them and process them elsewhere. As you definitely won't find some resources in abundant quantities on 1 g worlds that you will find in abundance on higher g worlds.

 

Edited September 7, 2019 by Spacescifi

[kerbiloid]

3 hours ago, Spacescifi said:

The resources on a 2g, 3g, or 4g world are NOT the same as on a 1g world.

So, stack two 100 kg steel bricks on each other and mine the 2g-steel (whatever it is) from beneath.

[KSK]

4 hours ago, Spacescifi said:

You misunderstand my point.

The resources on a 2g, 3g, or 4g world are NOT the same as on a 1g world.

Some resources under great pressure can exist in states we do not naturally have on Earth.

Granted, you may have to dig for metallic gases, but I rest my case.

That rests heavily on whether or not they stay metallic without the pressure.

Mine them and process them elsewhere. As you definitely won't find some resources in abundant quantities on 1 g worlds that you will find in abundance on higher g worlds.

Unless you're planning to make your hull out of raw rock, I can't see that it would make any difference. Sure, you might find some unusual ores or other minerals on a high-g world but once you've extracted the relevant metals from that ore - you've got plain old metal again, the same as you'd find on a 1g world or anywhere else.

 

[Spacescifi]

11 minutes ago, KSK said:

Unless you're planning to make your hull out of raw rock, I can't see that it would make any difference. Sure, you might find some unusual ores or other minerals on a high-g world but once you've extracted the relevant metals from that ore - you've got plain old metal again, the same as you'd find on a 1g world or anywhere else.

 

 

I wonder if it would be possible to make a metastable metallic gas alloy?

Mix it with another element to make it stable without the pressure?

Time will tell...

[kerbiloid]

25 minutes ago, Spacescifi said:

metallic gas alloy

(That strange moment when I realize that know nothing from fizzix).

26 minutes ago, Spacescifi said:

Time will tell...

This! A timed metal.
Slow down the time flow in the metal, and its atoms will never move, and the piece will never crash.

Edited September 7, 2019 by kerbiloid

[KSK]

1 hour ago, Spacescifi said:

I wonder if it would be possible to make a metastable metallic gas alloy?

Mix it with another element to make it stable without the pressure?

Time will tell...

Depends on the gas. I can give you any number of examples of metastable oxygen 'alloys'.

For hydrogen then, as you say, time will tell but personally I'm skeptical. By alloy, I'm presuming you mean something that's mostly hydrogen with just enough of another metal dissolved in it to stabilise it. There's already been quite a lot of research into such things back when everyone was getting excited about fuel cells and the so-called hydrogen economy. The big drawback to that was hydrogen storage and I'm not aware that it was a problem that was ever satisfactorily solved apart from good old fashioned high pressure gas cylinders. A metastable hydrogen alloy is revolutionary enough that I'm reasonably sure we'd have heard about it.

Metal hydrides are also a thing, although they're not really alloys. I've used some of them myself, lithium aluminium hydride for example, is a standard lab reagent. Just don't let it get in contact with air or water unless you particularly enjoy burning down your lab.

 

[Spacescifi]

18 minutes ago, KSK said:

Depends on the gas. I can give you any number of examples of metastable oxygen 'alloys'.

For hydrogen then, as you say, time will tell but personally I'm skeptical. By alloy, I'm presuming you mean something that's mostly hydrogen with just enough of another metal dissolved in it to stabilise it. There's already been quite a lot of research into such things back when everyone was getting excited about fuel cells and the so-called hydrogen economy. The big drawback to that was hydrogen storage and I'm not aware that it was a problem that was ever satisfactorily solved apart from good old fashioned high pressure gas cylinders. A metastable hydrogen alloy is revolutionary enough that I'm reasonably sure we'd have heard about it.

Metal hydrides are also a thing, although they're not really alloys. I've used some of them myself, lithium aluminium hydride for example, is a standard lab reagent. Just don't let it get in contact with air or water unless you particularly enjoy burning down your lab.

 

You work with chemicals? Nice!

I dunno... I just think in the mankind future will develop resources that we do not have now, which is what mankind has done in the past. We used to use bronze, then we developed our heating skills well enough for iron, and later steel.

It seems that there is a definite tech development path that must be taken that sooner or later results in new materials.

I really do find solid gases fascinating though. Read somewhere online where scientists made gas glass with interesting ( potentially useful) properties.

Edited September 7, 2019 by Spacescifi

[kerbiloid]

"solid" and "gas" are antonyms.

[Guest]

2 hours ago, kerbiloid said:

"solid" and "gas" are antonyms.

They're not. The antonym of "solid" is "non-solid". A solid gas is an oxymoronic expression, 

Also, "solid gas" is an awkward way of referring to what can better be described as a solidified gas. That is, a substance that is "normally" a gas, solidified one way or another.

The downside is, those exotics tend to fall apart outside extreme conditions. They can sometimes survive conditions that are slightly less extreme than the ones they were formed in, but not by much.

5 hours ago, Spacescifi said:

I dunno... I just think in the mankind future will develop resources that we do not have now, which is what mankind has done in the past. We used to use bronze, then we developed our heating skills well enough for iron, and later steel.

The next "resource" that will be developed will be carbon. It's perfect for making things out of because each carbon atom can connect with up to four others. You can get nanotubes, sheets of graphene, as well as more complex structures just by joining carbon atoms together. Amorphous carbon also has very good material properties.

BTW, iron is not more "advanced" than bronze. In fact, it's worse in most regards. Bronze cannons were much better than iron ones, for instance. However, the problem with bronze was always its expense. Making it required tin, which was extremely rare. Only a few deposits were known in ancient times, and tin trade shaped much of the early civilization development. Once it was discovered how to make iron useful for anything at all, it became widespread just because of how common it was. It wasn't until the discovery of steel that we had something better than bronze, and it was also an expensive good for a very long time.

[kerbiloid]

12 minutes ago, Dragon01 said:

The next "resource" that will be developed will be carbon. It's perfect for making things out of because each carbon atom can connect with up to four others. You can get nanotubes, sheets of graphene, as well as more complex structures just by joining carbon atoms together. Amorphous carbon also has very good material properties.

Then you make carbon nanorings and weave a nanocarbon 3d chainmail.
To protect against metallic gas swords.

Edited September 7, 2019 by kerbiloid

[Shpaget]

35 minutes ago, Dragon01 said:

iron is not more "advanced" than bronze. In fact, it's worse in most regards

I started to list all the reasons why bronze is better than iron, but you seem to have done that, so I'll just add that those same reasons are still true, and bronze is still ridiculously expensive compared to iron.

Recently I bough a piece of round bronze stock 20 mm in diameter, 300 mm long. It was $25. For pretty much the same amount I got more steel stock than I could carry.

[kerbiloid]

There are many bronzes, not every one requires tin. Just tin is the best. But as well (and much wider) the ancients were using arsenic.

Bronze is usually harder, but steel is stronger and has much higher melting point.
Also there is by orders of magnitude more iron ore than sulfide ones.

Edited September 7, 2019 by kerbiloid

[farmerben]

I was about to mention arsenical bronze.  

The great thing is every metal has value in space.  Even pure calcium can be used to make mirrors.  There is no oxidation problem to worry about.  

I expect asteroid miners to target high value, rare elements, but in the process produce lots of useful byproducts.  

There needs to be technologies and regulations to prevent asteroid mines from discharging dust.  There will be a strong incentive to find uses for everything.  

Sometimes in terrestrial mining the cost to move ore to a refining mill, or build a new refining mill is a huge portion of the cost. In the asteroid belt, transport costs are very low.  I suspect the largest ships for a long time will be ore carriers.  Even with mass drivers on some of the larger bodies, there will be plenty of demand for mining ships and ore carriers to go after small asteroids.   

[Guest]

In the asteroid belt, transport costs are actually very high. Asteroids are very far apart, and coasting between them takes a huge amount of time. In terms of travel time, each asteroid is closer to Mars and Jupiter than to one another. Asteroid miners would have to be self-contained colonies, with a refinery capable of processing everything that is on the rock it's attached to. Everything that isn't would have to be imported. You'd sell valuable stuff, and retain everything that's not worth transporting for local use.

19 minutes ago, kerbiloid said:

Bronze is usually harder, but steel is stronger and has much higher melting point.

Steel is stronger, but iron (cast or wrought) is pretty much inferior to bronze in every way, except for the price, which tends to trump everything else ever since money was invented. Yes, you could use arsenic instead of tin, but it's not all that common, either, and it complicates the manufacturing (though admittedly, manpower was cheap early on). In the end, unless you were nobility, you weren't getting any kind of bronze. Copper, at most, though of course iron ended up much cheaper than copper, too, thanks to its sheer abundance.

And yeah, this mostly stands today, except that steels is now cheap, while historically it was also expensive, because it was hard to make. There's a reason you occasionally hear of desperate morons trying to steal live copper wire for scrap (usually with predictable results). Bronze and brass are still status symbols today (it helps that they're very long-lasting, too).

[KSK]

9 hours ago, Spacescifi said:

You work with chemicals? Nice!

I dunno... I just think in the mankind future will develop resources that we do not have now, which is what mankind has done in the past. We used to use bronze, then we developed our heating skills well enough for iron, and later steel.

It seems that there is a definite tech development path that must be taken that sooner or later results in new materials.

I really do find solid gases fascinating though. Read somewhere online where scientists made gas glass with interesting ( potentially useful) properties.

Used to. It's been well over 20 years since I was allowed anywhere near a chemistry lab.

Regarding a tech development path that must be taken, I think it's probably only with hindsight that it looks like a path. In reality I suspect its a mix of many factors - the copper vs iron posts above this one being a good example of two of them (availability and therefore cost). Some materials were deliberately researched for a particular application, some were serendipitous discoveries that found an application later.

And, whilst we do still discover startling new materials occasionally (such as graphene), materials science is also getting good enough to give us fairly sound ideas of what is possible (even if impractical) and what will remain unobtanium for the foreseeable future. So I'm not convinced that it's merely a matter of waiting and radically new materials will be there to be discovered and used.

[StrandedonEarth]

About the only advantage I can see to mining a hi-gee world is that, depending on size, it could be more dense, implying more (and more pure) metals and less “slag”. Possibly more of the heavier metals too

[magnemoe]

52 minutes ago, StrandedonEarth said:

About the only advantage I can see to mining a hi-gee world is that, depending on size, it could be more dense, implying more (and more pure) metals and less “slag”. Possibly more of the heavier metals too

High gravity planets is probably not much of an thing, even terrestrial super earths tend to stay below 1.5g, distance to core also increases. 
We know one type of planets who has high gravity, its an rare class with density in the 15-20 kg/ liter ,  I assume planet is the core of an stripped bare gas giant, and lots is degenerated matter who is kind of metastable.
 They obviously is very close to the stars and tend to be places who makes Venus look very friendly. 

Now you could have some rare event there it get pushed outwards, graze it with an terrestrial planet to give it an terrestrial planet surface. 
And no mining them will not be practical. 
If you travel from another star in system dV is an joke, your engines however are optimized for space not landing. 
You are also gathering for your own use. Export does not make sense  

[Scotius]

Thing is: only things you would really need super-strong, exotic materials for would be military applications. And crazy, brachistochrone-flying interplanetary SSTO's. Your run-off-the-mill cargo\passenger hauler will only need to be strong enough to withstand the stress of its own engines firing. It even should be built of lightest materials possible, to get best thrust-to-weight ratio. And it should be cheap and widely accessible. Aluminium, steel, carbon, relatively low tech composites and alloys. IMO, the biggest advances in materials science probably will be concentrated on things like coatings, isolations, paints etc. Stuff that protects your ship from wear and tear in space - things like vacuum welding, outgassing and radiation-induced degradation.

[Spacescifi]

5 hours ago, magnemoe said:

High gravity planets is probably not much of an thing, even terrestrial super earths tend to stay below 1.5g, distance to core also increases. 
We know one type of planets who has high gravity, its an rare class with density in the 15-20 kg/ liter ,  I assume planet is the core of an stripped bare gas giant, and lots is degenerated matter who is kind of metastable.
 They obviously is very close to the stars and tend to be places who makes Venus look very friendly. 

Now you could have some rare event there it get pushed outwards, graze it with an terrestrial planet to give it an terrestrial planet surface. 
And no mining them will not be practical. 
If you travel from another star in system dV is an joke, your engines however are optimized for space not landing. 
You are also gathering for your own use. Export does not make sense  

 

Depends on how advanced propulsion systems or transport methods are.

 If reueling is no longer an issue, or asteroid bases can literally base site to ship teleport fuel to a ship on a ranged flyby, refueling becomes easier.

In the cases of teleport refueling, resource bases would have to be built beforehand for any future exploring ships.

In that case, provided one had a moon base... export would be a more reasonable endeavor.

 

3 hours ago, Scotius said:

Thing is: only things you would really need super-strong, exotic materials for would be military applications. And crazy, brachistochrone-flying interplanetary SSTO's. Your run-off-the-mill cargo\passenger hauler will only need to be strong enough to withstand the stress of its own engines firing. It even should be built of lightest materials possible, to get best thrust-to-weight ratio. And it should be cheap and widely accessible. Aluminium, steel, carbon, relatively low tech composites and alloys. IMO, the biggest advances in materials science probably will be concentrated on things like coatings, isolations, paints etc. Stuff that protects your ship from wear and tear in space - things like vacuum welding, outgassing and radiation-induced degradation.

 

You want the best fuel to weigh ratio ever? Use semi-rigid inflatable spacecraft.

 

If we ever develop materials that are inflatable yet heat resistant, it could lead to some weirdly useful spaceship equipment.

 

Imagine... inflatable NTR engine cores! Inflatable fuel bladders (tanks but inflatable).

 

May be not possible now, but with science it seems the answer to many developments is often it depends, rather than a hard no.

Powered flight was impossible for a long time since we lacked powered motors.

Thus the necessary unknown technology path that only the future shall reveal.

Edited September 8, 2019 by Spacescifi

[Guest]

1 hour ago, Spacescifi said:

Inflatable fuel bladders (tanks but inflatable).

This has been possible since the 50s, and used on a rocket way back then. The Atlas series used literal inflatable fuel tanks made out of very thin aluminium foil, before Atlas V changed the first stage to get rid of them. Centaur upper stage also uses similar structure. It is called a balloon tank, and makes the rocket very lightweight. The downside is, handling the tank is hard. You have to keep the pressurized with nitrogen when empty. As it happens, most such tank designs don't take being deflated too well. Although you could probably built ones that can be deflated for storage, if you needed to.

NTR engine cores can't be made inflatable, because they're filled with uranium. Inflatables are useful, but they're not miracle tech. They give you free volume, but not free mass.

Edited September 8, 2019 by Guest

[Spacescifi]

2 hours ago, Dragon01 said:

This has been possible since the 50s, and used on a rocket way back then. The Atlas series used literal inflatable fuel tanks made out of very thin aluminium foil, before Atlas V changed the first stage to get rid of them. Centaur upper stage also uses similar structure. It is called a balloon tank, and makes the rocket very lightweight. The downside is, handling the tank is hard. You have to keep the pressurized with nitrogen when empty. As it happens, most such tank designs don't take being deflated too well. Although you could probably built ones that can be deflated for storage, if you needed to.

NTR engine cores can't be made inflatable, because they're filled with uranium. Inflatables are useful, but they're not miracle tech. They give you free volume, but not free mass.

 

My solution would be liquid methane inflatable bladders with liquid oxygen.

 

For deep space missions I would add more more inflated bladders to it while in orbit. It will basically look like a rocket with a bunch of balloons strapped to the side walls.

Before the mission, I would send up a nuclear reactor, install it on the ship in orbit, and use NTR LOX/methane propelled rocketry for orbit to orbit transfer. If I wanna land I would just have to use smaller shuttles or pods.

 

Actually, ot made me think of a ship composed of tons of pods fitted together that can detach, like the Suliban helix composed of many pids joined together. In real life each could be equpped with a parachute and landing thrusters so that gradually, the whole ship could land. Taking off again is not happening though, as it likely took several launches to assemble the thing.

[kerbiloid]

10 minutes ago, Spacescifi said:

My solution would be liquid methane inflatable bladders with liquid oxygen.

???

Spoiler

Well... That's rather unusual...
But why not?

Just it would take a lot of cows to get them. On another hand, they also produce the required methane.

[Spacescifi]

1 minute ago, kerbiloid said:

???

  Hide contents

Well... That's rather unusual...
But why not?

Just it would take a lot of cows to get them. On another hand, they also produce the required methane.

 

Haha, goat haggis. One day I might try it.