Gas giant mining

[abomination]

You can't actually use the vacuum of space to pull up the hydrogen because things don't work that way. I'll explain:

The reason a straw works is because when you reduce the pressure in the straw, the atmospheric pressure on the top of your drink pushes the drink into the straw. If you sealed your cup and had only the straw coming out, you couldn't suck up any liquid. (Unless your glass was flexible, like when you use those little milk cartons and close the top on your straw, or when you suck on a water bottle that doesn't have a good enough vent - when you suck in, the sides of the container collapse.) Likewise, if you were in a vacuum, you couldn't drink an unsealed container with a straw, though you could squeeze the container, effectively providing your pressure through mechanical means instead of gas pressure.

Another way to think about it - if a tube in space could suck away a small amount of atmosphere, then a really big tube could suck away a whole lot of atmosphere. What if the tube were as big as the whole planet? Since we still have an atmosphere, empirically the vacuum of space won't suck away an atmosphere.

Doh, I hadn't thought of that. Can't suck harder than a vacuum. But you can push stuff up from below

The bigger the hose, the more gas it can move.



I suggested plasma, since you could use magnetic fields in the tubes to "pump" it up. But mostly because I thought a giant pulsing tube of plasma would look cool, and the whole gas mine idea has "Rule of Cool" written all over it.

or some sort of mechanical device pushing gas past some sort of one way valve. Which isn't as pretty.

 

[Rigel Stardin]

As a kid (Many many many moons ago), I watched an experiement where they attached a balloon to a hose, placed it in a chamber and reduced the air pressure around the ballon. The ballon inflated because there was no pressure surrounding the outside of it?

 

[hdan]

As a kid (Many many many moons ago), I watched an experiement where they attached a balloon to a hose, placed it in a chamber and reduced the air pressure around the ballon. The ballon inflated because there was no pressure surrounding the outside of it?

Yes, but the hose didn't have to lift that air into a much higher potential energy state. In fact, the weight of that air pushed into the balloon, in a way going "down hill", until the elasticity of the balloon matched the pressure of the air.

If you stick a straw into a glass, does the water spout out the top? The water between the surface of the glass and the end of the straw weighs more than (and is obviously denser than) the air at the other end of the straw, yet it can't push the water up.

But if you put the end of that straw (say it's a bendy straw or something) LOWER than the top of the glass, the water will flow up and over, ultimately winding up "down hill". (The Siphon effect.)

Which gives me an idea - if you put a gravity generator on one edge of the siphon calibrated to a higher force than the planet you're siphoning from, things might work out. I'll let those better at physics than me work that out...

 

[aramis]

Siphoning only works if you can get pressure to lift it in the first place.

 

[Rigel Stardin]

My limited knowledge of real world science suggest that sticking a straw into a basketball would force the air out straw because of the pressure inside the basketball. Yes I know atmospheric pressure is putting pressure on the outside of the ball as well which inturn aides in the release of air from the basketball.

(Warning: Discovery Channel Science involved

One documentary on volcanic lakes in Africa stated that gases form layers in these lakes and if a landslide disrupts these layers the lake turns overs. To stop this from happening, they inserted a tube into that layer which cause the gases to be released using the pressure of the water.

The thought here is gas gaint atmospheres are at a higher density than earth atmosphere. Striking the right layer would allow the hydrogen to be expelled using the weight of the atmosphere to push the gas up the pipe to the station.

Question: Would a platform placed in geocentric orbit also provide force through rotation to pump the gas upward?

 

[Icosahedron]

My 2Cr:
Orbital elevators and tubes are probably an interrim tech if they ever prove feasible at all. IMO, once grav propulsion is matured it will supplant any such devices.

H&S-free drone or remote-piloted fuel shuttles (of whatever size you like) can bring fuel up to an orbiting station (in close orbit, so reducing time and effort) using off-the-shelf components rather than manufacturing a specialised tube.

And a hull fracture on a shuttle results in a single vessel leaving the conveyor belt, whereas a hull fracture on a tube could result in half the tube plummeting into the murky depths...

And you could use the shuttles for surveying, or use them as launches, or lifeboats, or mount a turret on them to help defend the station, or...

 

[HG_B]

The thought here is gas gaint atmospheres are at a higher density than earth atmosphere. Striking the right layer would allow the hydrogen to be expelled using the weight of the atmosphere to push the gas up the pipe to the station.

You are forgetting that gravity is pulling it towards the planet. The pressure would have be strong enough to propel the weight of the column of gas to greater than escape velocity. Not gonna happen as there is no pressure vessel in the 1st place

 

[hdan]

My limited knowledge of real world science suggest that sticking a straw into a basketball would force the air out straw because of the pressure inside the basketball. Yes I know atmospheric pressure is putting pressure on the outside of the ball as well which inturn aides in the release of air from the basketball.

The walls of your basketball are trying to contract. The air in the ball prevents that. If you place that ball in a vacuum, the air will flow out to the lower energy state.

In the case of a planet, the gravity is holding in the air. If you put a straw into space, the gravity will still hold in the air since "higher up" is a higher potential energy state.

Otherwise, you could build a perpetual motion machine by making a 50 mile high tower and mounting a wind turbine in it.

One documentary on volcanic lakes in Africa stated that gases form layers in these lakes and if a landslide disrupts these layers the lake turns overs. To stop this from happening, they inserted a tube into that layer which cause the gases to be released using the pressure of the water.

Right. It is just the same as your basketball example.

The thought here is gas gaint atmospheres are at a higher density than earth atmosphere. Striking the right layer would allow the hydrogen to be expelled using the weight of the atmosphere to push the gas up the pipe to the station.

This really does all come down to why does an atmosphere stay on a planet? If pressure was what held the air down, then sure, the straw thing would work. But it's not pressure holding "in" the atmosphere, it's gravity, which is working on all the air, all the time. Those "sea level" experiments where you create a vacuum work because you are at roughly the same gravitic potential, and you are making a lower pressure zone than would normally exist at that altitude.

I hope I'm explaining this correctly. (And even more so that I'm actually not mistaken myself.) You can't make a "more vacuum-y vacuum" in orbit. Right inside the edge of the atmosphere (where you can still measure air pressure), you could make a vacuum, but the amount of "suck" you'd get out of it is very slight compared to what you get down in the thicker parts of the atmosphere. And since gravity is holding the atmosphere in place, the best you could do is slightly de-pressurize the upper parts of the straw. And even that involves YOU doing the pumping, not a gusher effect.

Question: Would a platform placed in geocentric orbit also provide force through rotation to pump the gas upward?

An interesting question. My supposition is that no, it wouldn't work unless the planet was spinning very quickly, but I was never any good at centripetal acceleration calculations.

 

[aramis]

No, the geostationary orbit would NOT work; if the planet was spinning fast enough for the gas to rise, it already would have risen. Same issue as a siphon.

 

[hdan]

No, the geostationary orbit would NOT work; if the planet was spinning fast enough for the gas to rise, it already would have risen. Same issue as a siphon.

Doh, of course.

 

[Rigel Stardin]

So we are left with only one option then.
...The Rule of Cool...
Converting the Hydrogen into plasma and sending it up to the tanks in orbit.

Power requirement?

Using the planet's magnosphere, reactor or solar?

 

[AlHazred]

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.

 

[whartung]

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.

If you're mining fuel in bulk from a Gas Giant, and shipping them in system to the starport(s), you're not going to be using 30ton cutters.

You're going to be using the biggest tanks you can. Like 5000 ton fuel shuttles.

In fact, what you would probably do use fuel tugs to take large (1000s of tons) tanks to put them on course. Tugs at the giant fling them in system, and tugs at the other end "catch" them, dock them, transfer them (or stash them, or whatever) at the starport, then fling the empties back.

Doesn't really matter if they take a couple weeks to get where they're going. There's just a long chain of tanks going in and out.

 

[Spinward Flow]

@whartung answered before I could.

If you're industrializing the production in order to meet demand, you're probably looking at something akin to a kind of "bucket brigade" doing a sort of "pitch & toss" on orbital trajectories between locations. Rather than doing a powered fuel shuttle for every shipment, instead you've just got a lot of "unpowered tanks" that get filled up and accelerated onto a trajectory by a maneuver tug. Once the trajectory on the "throw" end gets finalized, the tug undocks from the tank and leaves the tank flying on an inertial trajectory towards a destination point (which gets reported). Same thing happens on the "far end" of the operation, except there it's more of a catch and retrieve for detanking. The tanks can then be filled with "whatever is needed for the return journey" (water, oxygen, nitrogen, whatever) and the tanks get "thrown" by maneuver tug back towards the orbit where they started from, completing the round trip.

Capital investment is needed for the maneuver tugs on both ends (will need some extras so you can have maintenance rotations without disrupting service) and the tankage infrastructure needed to "fling supplies" between both ends of the operation. The orbital trajectories of the unmanned tanks will be known to system defense boats (if any) so attempting to steal any of the (unattended and unmanned) tanks while on inertial orbit trajectories becomes something of a "steal from at own risk" type of venture (of course, some will still try it when desperate enough). There also the "mining station" and contracts with starport(s)/spaceport(s) to manage, along with all of the personnel needed to keep the party going.

 

[Condottiere]

On site.

 

[AlHazred]

You don't want to risk the very big, expensive ships in the GG's atmosphere, though. I'd pictured the modular shuttles running the loads to the larger ship, orbiting above the atmosphere. The tanks can pump while the ship continues its orbit, then, when full, it launches to the star ports.

I'd imagine you'd have several stations in operation.

Docking is easier if the tanker is smaller than the mining rig...

 

[AlHazred]

I guess I'm trying to find reasons to use the deckplans. Might require some handwaving, like you do for a lot of the Travellerisms (no widespread AI, fuel costs low enough to allow for interstellar trade, etc.)

 

[whartung]

You don't want to risk the very big, expensive ships in the GG's atmosphere, though

Of course you do.

It's, apparently, not that risky of an endeavor if every Tom, Dick, and Free Trader has fuel scoops and is running around skimming Gas Giants.

The single dominant factor in fuel production is TIME. Extracting the raw materials (from wherever), and then processing it.

This is an operation that scales well to volume, and you have to appreciate just how much fuel is necessary, especially how much is necessary to justify the operation in the first place.

A 30 ton fuel shuttle is, literally, a drop in the vast tanks of a 10K, 20K, 100K J2-J3 freighter. "You're going to need a bigger boat."

I actually ran the math on this, it does take capital (but if there's anything in the Imperium, there's capital -- holy dollar signs, is there capital!).

But it's "worth it" at 500Cr per ton, if the demand is there.

Even in a "small ship" universe, the ships may be smaller, but the cargo demand is there, so it's just more ships. More, less efficient ships, so, even more fuel is needed.

 

[Spinward Flow]

Things get fun when you need to start thinking in terms of interstellar industrial scale gas giant extraction for fuel(s).
Use of a map will be helpful for how to frame this possibility.

Gitosy/Rhylanor is TL=9 with a type B starport ... and it's a spherical asteroid belt rather than an ecliptic orbit belt.

For "extremely high volume" transport of fuels from other star systems there are logistical challenges.

@ J1:

• Gerome/Rhylanor is an interdicted mainworld. There are 10 other planets in the system and 1 gas giant (which has no details in the Travellerwiki).
• Heroni/Rhylanor has an exotic atmosphere (code: A) and no hydrographics (code: 0) ... and there's no gas giant in the star system, so "gas mining" for starport fuel(s) is basically in the category of "you took a wrong turn at Albaquerque Rhylanor").

@ J2 ... you've got Kegena, Cipatwe and Vanejen all within range ... but now you've got a different problem.
And of those choices, Vanejen requires a streamlined hull (atmosphere: 8) in order to reach the world's ocean, rather than being able to get away with a Close Structure (configuration: 4) gas giant orbital skimmer.

No matter what happens, any kind of fuel tanker/transport starship is going to need to be able to make 2 jumps before needing to refuel.

• J1+1 between Gerome <> Gitosy isn't that bad, consuming 20% of the hull displacement in order to make a round trip.
• J2+2 between Kegena or Cipatwe (or Vanejen) <> Gitosy starts getting prohibitive, because now you're consuming 40% of the hull displacement to make a round trip. That's going to have a pretty significant impact on the "delivery fraction" that can be deposited at Gitosy with each run.

What's probably going on would be some sort of interstellar "skimmer" fleet of 800 ton tankers equipped with TL=9 D/D/D drives that are dedicated to making the Gitosy -> Gerome -> Gitosy run on the regular in order to obtain sufficient fuel reserves for the Gitosy starport (type B). Could even be done as a sort of "modified pitch & toss" with an additional (jump) step.

1. Large tanks are marshaled by non-starship maneuver tugs from the production plant in close orbit around the Gerome system gas giant out to a "beyond jump shadow" parking orbit for rapid pickups.
2. Large tanks in the parking orbit are collected by starship jump tugs for transit to Gitosy.
3. After breakout in the Gitosy system, the large tanks are put into a parking orbit convenient for retrieval.
4. Non-starship maneuver tugs deorbit maneuver the large tanks from Gerome to their intended destination(s) @ Gitosy.
5. The starship jump tug maneuvers to collect a different large tank from a different parking orbit for tanks intended for transport back to Gerome.
6. After breakout in the Gerome system, the large tank is put into another parking orbit around the Gerome gas giant.
7. Non-starship maneuver tugs deorbit maneuver the large tanks from Gitosy to their intended destinations(s) @ Gerome.
8. Wash. Rinse. Repeat.

Point being that if you've got 8 starship jump tugs working in a rotation, they can basically spend "almost all of their time in jump" without entering the jump shadows. With good navigation and piloting, a jump tug could spend slightly over 16 hours (for routine basic post-jump maintenance) between jumps for a very rapid turnaround tempo of operations. You wind up needing fewer non-starship maneuver tugs on each end than the number of starships making jumps between the two star systems. The whole arrangement turns into a sort of "mult-modal" transport deal (non-starships plus starships) to increase the transfer rate of the operation, allowing different craft to "specialize" in different segments of the business use case (maneuver tugs don't need jump drives, for example).

 

[AlHazred]

I came up with a list of systems in the Spinward Marches with gas giants, but no hydrographics on the mainworld, since those would be the prime candidates for this sort of thing. I need to go through the list and filter out systems that have no other possibilities for fuel hydrogen -- no asteroid belts, no hydrographics on other worlds in the system. Those systems will need to use gas giant mining rigs.

Mainworld	Hex	Subsector	GG
Zeycude	0101	Cronor	3
Reno	0102	Cronor	3
Atson	0111	Querion	3
Bael	0218	Querion	2
Sansibar	0412	Querion	1
Jinx	0440	Five Sisters	2
Penelope	0533	Five Sisters	3
Terant 340	0622	Darrian	3
Spume	0727	Darrian	4
Anselhome	0820	Querion	1
975-452	0840	Five Sisters	1
Quare	0915	Vilis	4
Inchin	0938	District 268	3
Ruby	1005	Jewell	1
Zenopit	1010	Jewell	2
Choleosti	1018	Vilis	1
Mjolnir	1121	Sword Worlds	2
Bowman	1132	District 268	1
Ao-dai	1201	Jewell	2
Edinina	1213	Vilis	1
Nirton	1332	District 268	1
Farreach	1402	Jewell	5
Caliburn	1430	Sword Worlds	4
Smoug	1729	Lunion	2
Grote	1731	Glisten	4
Lydia	1733	Glisten	2
Melior	1736	Glisten	4
Dinom	1811	Lanth	1
Zaibon	1825	Lunion	2
Pixie	1903	Regina	1
D'Ganzio	1920	Lanth	2
Ianic	1924	Lunion	4
Glisten	2036	Glisten	1
Yori	2110	Regina	3
Romar	2140	Glisten	2
Inthe	2234	Glisten	4
Tsarina	2236	Glisten	1
Shionthy	2306	Regina	4
Resten	2323	Lunion	1
Rethe	2408	Regina	3
Gandr	2425	Lunion	3
Pimane	2527	Mora	3
Squanine	2536	Trin's Veil	3
Dobham	2537	Trin's Veil	3
Thisbe	2539	Trin's Veil	2
Macene	2612	Rhylanor	1
Robin	2637	Trin's Veil	2
Jae Tellona	2814	Rhylanor	3
Pavanne	2905	Aramis	5
Brodie	3021	Mora	4
Grille	3026	Mora	1
Tee-Tee-Tee	3038	Trin's Veil	2
Patinir	3207	Aramis	3
Bevey	3216	Rhylanor	4
Tacaxeb	3218	Rhylanor	1
Ramiva	3233	Trin's Veil	3