Gas giant mining

[warwizard]

Now I have seen attempts to bridge a J-4, J4 gap using book 2 designs. Most of you should know of me as a T4 FF&S starship engineer. So in T4 we can over engineer our jump drives to accomodate external cargos. So J-6 drives require 7% of the hull volume, and a J-1 drive requires 2% of hull volume. So a 100dT J-6 ship can carry 250dT of external cargo for the same size jump drive, while limiting jumps to J-1. As J-6 can use drop tanks, we have a few points of usage where drop tanks can be used.
J-1 (has max jumpable volume of 350 dT) costs 35 dT of fuel at max load.
J-2 (has max jumpable volume of 233 dT) costs 46 2/3 dT of fuel at max load.
J-3 (has max jumpable volume of 184 dT) costs 55.2 dT of fuel at max load.
J-4 (has max jumpable volume of 140 dT) costs 56 dT of fuel at max load.
J-5 (has max jumpable volume of 116.6 dT) costs 58.3 dT of fuel at max load.
Note that for J-1 and J-2 jumps the external tanks carry the grappels for the 100 dT ship saving 7.5 dT, and 1.8 dT respectivly. And the drop tanks at the initial jump carry armor factor 20, and the drop tank carries the grappel and a small thruster to aid in positioning and recovery. Sort of like a fuel tender that comes up to the ship grapples it and goes through the pump for jump phase before detaching and thrusting away from the jump bubble danger zone.
The crew of this ship is one person with Engineering 6 and pilot 6, no bridge is required for a 1 person crew, just a workstation and a half stateroom.
The J4 point is interesting for this discussion, as the 40 Dt external tankage is a traditional 40 Dt drop tank, giving you the initial jump with the fuel tender , the intermediate jump with the drop tanks, and the ship arriving at the destination with internal tankage of jump fuel untouched, and 2 weeks of power plant fuel consumed. (T4 FF&S this PP fuel is much less than book 2's 20 tons, especially for a 6 power point plant used at power -4).

There is nothing in the rules stopping you from installing a larger than needed jump drive so that you can act as a jump frame for a detachable LHyd tank. Although as you get larger you trigger having to have a bridge and a larger crew.

I just would not want to be the poor pilot spending 95% of life in jump space, alone.

 

[Enoki]

For large-scale gas giant harvesting of gases, it would be easier to choose a close in satellite of the gas giant and use essentially a long flexible hose to move / draw gas from the gas giant to the satellite where it is processed. That way you avoid the need for an expensive space station or ship replacing it with a base on the chosen rock orbiting the gas giant.

To do this you use something like this:

What you do is use locally produced gas and inject it at high pressure via the nozzle (red arrow). This creates a low pressure zone behind it drawing gas from the gas giant (blue arrows) and both are ejected to a storage tank (purple arrow). You can cycle the same gas repeatedly through the nozzle to make this work. Run multiple hoses to get greater quantity. Shouldn't be too hard to get very high pressure, high velocity gas to run the system given decent high tech level equipment.

So, if you have say, 5000 psi gas being shot through this eductor, it will create a massive low-pressure zone behind it that pulls the gas through the hose. The volume of gas will roughly equal the volume of gas used to create the low-pressure zone. So, if you were putting a cubic meter of gas through this every second, it sucks up a cubic meter of gas from the gas giant. You can just keep reusing the already harvested gas to keep the system going. All you need is a way to build the necessary pressure for the nozzle gas.

 

[Spinward Flow]

For large-scale gas giant harvesting of gases, it would be easier to choose a close in satellite of the gas giant and use essentially a long flexible hose to move / draw gas from the gas giant to the satellite where it is processed. That way you avoid the need for an expensive space station or ship replacing it with a base on the chosen rock orbiting the gas giant.

Um ... no ...

Your first problem is going to be the Roche Limit ... which means that any "close in satellite" is still going to be a "long way away" from the cloud tops of a gas giant.

The second problem is that your "long flexible hose" is going to have to be sweeping through a region of space that has "nothing else moving/falling through it" ... which will NOT be the case if there's any sort of Ring Rain going on (or indeed, any other variety of "abrasive matter" spiraling down from orbit into the planetary atmosphere). If the region of space you're sweeping through IS NOT CLEAR of Foreign Object Debris (FOD), you can expect your "long flexible hose" to have a limited lifespan (potentially VERY limited!). Let's just say that mean time between failures is not going to be measured in decades ...

And before anyone suggests that "nothing like that could possibly happen" ... consider that an impact from FOD has already occurred on the James Web space telescope orbiting the L2 point of Terra. A small interplanetary fragment struck the telescope mirror, causing irreparable damage (which the telescope can compensate for and has ever since).

We like to think that "space is just a big empty" and call it a day.
Unfortunately, that's not actually true.

At orbital velocities, even paint chips can cause pretty significant impact damage (LINK).

While the tiny sizes of most micrometeoroids limits the damage incurred, the high velocity impacts will constantly degrade the outer casing of spacecraft in a manner analogous to sandblasting. Long term exposure can threaten the functionality of spacecraft systems.

My point being that ANY gas giant with rings (and at this point, we've confirmed that ALL of the gas giants in the Sol star system have rings!) is going to experince some form of Ring Rain which will then make it hazardous to "dangle a long flexible hose" from a satellite outside the Roche Limit.

 

[Dragoner]

Just make it self sealing. A siphon is pretty simple. KISS is a basic principle of engineering.

 

[Condottiere]

Technological level nine hull.

 

[Spinward Flow]

Your first problem is going to be the Roche Limit ...

For those who don't know (without a lookup table).
LINK

Technological level nine hull.

A "long flexible hose" ... made out of TL=9 hull material (which is TL=7-9 Composite Laminates) ... that will need to be hundreds of thousands of kilometers long ... will be cheaper than building a "floating" mining platform station that runs on gravitics located within the atmospheric envelope of a gas giant ...?

Color me skeptical of that idea ...

 

[Enoki]

For those who don't know (without a lookup table).
LINK

A "long flexible hose" ... made out of TL=9 hull material (which is TL=7-9 Composite Laminates) ... that will need to be hundreds of thousands of kilometers long ... will be cheaper than building a "floating" mining platform station that runs on gravitics located within the atmospheric envelope of a gas giant ...?

Color me skeptical of that idea ...

Use one of those tethered space station things. A hollow tether allows for siphoning of gas. At higher tech levels I would suspect you could use a pair of asteroids as the end points.

I see the biggest drawback to gas giant gas mining as being gravity.

 

[Condottiere]

Self sealing materials are worth volume in gold.

 

[kilemall]

Whenever TL for beanstalks are viable, this should be too.

On the other hand independent of the orbiting debris issues, the wind storms of a gas giant would present stresses. The hoses would only run down to the thin part of the atmosphere so maybe less stress than a thicker atmosphere of a rock planet, but definitely there.

Maybe an electronically controlled wing surface with weights near the intakes to keep the hoses pointed down and not break suction by whipping around.

I would envision 3 or 7 hoses bundled together as one for mutual strength and failover in case one or more hoses gets damaged.

 

[whartung]

I dunno, there has to be some practical limit on how long a hose can be. Or the ratio of length to diameter. Some kind of over powering friction that cancels out the the suck force (that's a technical term) making super long hoses impractical or impossible. At some point the medium in the tube outweighs the strength of the suction and things stall, or the housing collapses.

(Let me cite the disaster that is paper straws and milk shakes...)

 

[Spinward Flow]

I see the biggest drawback to gas giant gas mining as being gravity.

I see the biggest drawback being ... displacement tonnage.

Let's be conservative and suggest using a 10cm diameter cylinder that is 100,000,000 meters in length.
What's the volume of that cylinder?
And from that, what's the displacement tonnage?

πr² for the circular area = π(0.05)² for the tubular diameter in m²
πr² * length for the volume = π(0.05)² * 100,000,000 meters

m³ answer ... 785,398.16339745m³ per 100,000 km of length

785,398.16339745 / 14 = 56,099.8688141 displacement tons per 100,000 km of length

And that's JUST for a "thin flexible straw hose" that's a mere 10cm in diameter to siphon gas from the upper atmosphere to beyond the Roche Limit.

Now consider that if you're using a "beanstalk" arrangement at a gas giant, if you have to respect the Roche Limit then you're probably going to need ... 2+ ... 100,000 km lengths of your "thin flexible straw hose" ... which means you're spending OVER 100+k dtons just on the "pipe" before even allocating anything towards doing "useful work" of collecting and processing those atmospheric gases.

Self sealing materials are worth volume in gold.

Being able to create matter out of nothing lets you MAKE the gold too ...

 

[Silverhawk]

Of course, at a sufficiently high tech level where you can completely manipulate gravity you make a gravity source that just pulls the gas off.

 

[AlHazred]

Of course, at a sufficiently high tech level where you can completely manipulate gravity you make a gravity source that just pulls the gas off.

Look, if we're being that advanced, then I'm just popping J- and M-drives on Jupiter and tooling around the cosmos with my own gas giant. And when Jupiter runs out of hydrogen, I'll just use another gas giant... maybe Assiniboia. There's no law that says I can't!

 

[Dragoner]

I've been noodling around with Mark Lucas reimagined deckplans for the Ormston-class 5000-ton Gas Mining Station [elevations, deckplans: deck 1-3, deck 4-6, deck 7-12, deck 13-16, deck 17-20, all decks on one sheet; renders: 1, 2 (with callouts)], which was inspired and informed by the gas-mining ship in the adventure "Sky Rig" by Paul Ormston from White Dwarf #57 (September 1984). Mark Shepard put in a lot more space, which I like -- I'm one of those who loves the sense of interior space in the movie Alien. Empty (?) space. So, I'm a fan. But that leaves a lot of extra spaces to define. I like the three rings of staterooms, and how some staterooms are obviously meant as quarters for shuttle crews, as they have limited access to the rest of the station. But what sorts of rooms are they going to need in a Gas Mining Station? Probably labs, for testing samples and new refining processes. Recreation rooms? I'm tempted to put in a franchise or two, so it more resembles the mining station from Outland (1981).

My thought process was, some systems are very high traffic, but they don't have any water worlds and few asteroids. You can mine the gas giant rings (probably?) but it would probably be more efficient to have gas giant mining operations to support the merchant traffic. That would require steady shipments of refined hydrogen from the rigs to the starports, which I imagine is probably accomplished with Modular Cutters fitted with 30dt fuel modules.

I use this just with a tether.

 

[Silverhawk]

Look, if we're being that advanced, then I'm just popping J- and M-drives on Jupiter and tooling around the cosmos with my own gas giant. And when Jupiter runs out of hydrogen, I'll just use another gas giant... maybe Assiniboia. There's no law that says I can't!

Okay, so how much a square foot does Jupiter cost? Or is this the ultimate heist?

Our top story tonight, Jupiter is gone. Authorities baffled.

 

[AlHazred]

Okay, so how much a square foot does Jupiter cost? Or is this the ultimate heist?

Our top story tonight, Jupiter is gone. Authorities baffled.

A heist implies a crime was committed, and I see no laws about "stealing a planet!" Carry on as normal!

 

[Spinward Flow]

A heist implies a crime was committed, and I see no laws about "stealing a planet!"

Only because Grandfather arranged for the deaths of everyone who thought "stealing a planet star system" was deplorable ...

 

[kilemall]

A heist implies a crime was committed, and I see no laws about "stealing a planet!" Carry on as normal!

Normal in the Zimverse.

 

[Condottiere]

Home Owners Association injunction.