The perils of Gas Giant Fuel Skimming

[Bishop]

We're not talking about parking and sticking a hose out a window here. The ship is still going to be orbitting the GG. The only manuever force required is whatever is needed to counteract the atmosphereic drag. 1-G should be more than capable for allowing a orbitting streamlined ship to skim. 3-G would allow the same ship to skim through higher density gas and fill up faster. I don't see any problem as long as the atmospheric drag is less than the manuever G regardless of GG size.

IMHO

T.

Originally posted by Anthony:
Realistically, gas giant densities probably aren't very variable, but anything other than a small gas giant (saturn-sized) isn't safely skimmable by a 1G ship at all. A 3G ship can do jupiter-sized objects, larger objects require increasingly high thrust.

 

[themink]

Originally posted by Bishop:
[QB]We're not talking about parking and sticking a hose out a window here. The ship is still going to be orbitting the GG. The only manuever force required is whatever is needed to counteract the atmosphereic drag. 1-G should be more than capable for allowing a orbitting streamlined ship to skim. 3-G would allow the same ship to skim through higher density gas and fill up faster. I don't see any problem as long as the atmospheric drag is less than the manuever G regardless of GG size.

IMHO

T.

QB]

But surely the ship has to be going slowly enough that the atmospheric friction doesn;t just melt the ship arround you. The orbital mechanics allows you to make a slingshot pass without manuevering at all and dipping into the atmosphere, but all that comes out the other end is a fused blob of metal. At least in MTU

I put limits on the G rating needed at each gas Giant - they have to be going slowly enough that the hull survives, which means that they need the maneuver drive to escape plummeting to their deaths.

Older gas Giants and those with higher proportions of iron get a higher G rating (IMTU). Without this, everyone just puts a fuel processor on their ship and stops buying fuel - Many ships do that anyway, but hey.

 

[Vorlanth]

Originally posted by savage:
How deep into a gas giant would a ship need to go for hydrogen? Certainly not the surface.

By the surface, do you mean atmospheric surface or actually the surface of the semi-solid core that usually exists under all that gas?

My guess is you don't need to go that deep, depending on how long you're willing to wait for the fuel tanks to fill. Since Hydrogen is the lightest of gases, any pure hydrogen that hasn't escaped into space is likey to be in a highly diffuse state at the periphery of the gas giant's atmosphere. For heavier, but more likely candidates for fuel to refine, you might dive deeper to access large, dense clouds of methane - which are themselves fairly bouyant. So overall, IMHO you wouldn't have to head in to deep to find suitable fuel (sure it has contaminates, but that's what a fuel processor is for).

Anyone have a differing opinion regarding this issue of how deep you'd have to dive?

 

[savage]

Wow. Plently of healthy discussion.

Far-trader
Well I won't judge if it's an excellent or scientific description, nor even if it's a great reference, but it is at least canon. It's part of the same text for CG Lifters in FF&S "... neutralize most... (approximately 99% of gravitational force, beyond which power use becomes prohibitive)." I'm sure they could have just as easily picked 99.9% or 90%, or any value, being that it's a handwave anyway.

Thanks for pointing out its canon. I won't have my Traveller books for several weeks. I suppose we could except it as standard. I'll have to reread it but it seems to me that CG Lifters would allow high atmosphere access to almost every world.

Bishop

We're not talking about parking and sticking a hose out a window here. The ship is still going to be orbitting the GG.

Not exactly. But for the Imperium to survive a TL15 govt would be thinking of refueling much the way we think of mid-air refueling. Not easy but a repeatable activity.

Vorlanth
Since Hydrogen is the lightest of gases, any pure hydrogen that hasn't escaped into space is likey to be in a highly diffuse state at the periphery of the gas giant's atmosphere. For heavier,...

That is what I thought. So, it really depends how much of a hurry your in.

The Mink
But surely the ship has to be going slowly enough that the atmospheric friction doesn;t just melt the ship arround you.
Without this, everyone just puts a fuel processor on their ship and stops buying fuel

Mink, we're talking TL10-15. The shuttle (at least durring early operations) would reach reentry speeds of Mach25. Do we really think that 3-G acceleration would burn up an armoured starship?

I really haven't seen much addressing the simplicity of TL17 refueling and the risks of TL10
refueling on a GG. Wouldn't TL15 piloting programs and sensors be more likely to pick up probably issues during the skimming?
Seems to me that you might actually get a million ton refueler in orbit around a key GG (with refuelling skimmers hanging in the high atmosphere all the time pumping fuel into its tanks). The govt might prohibit refueling due to the high quantities of vessels doing it (Capital or a sector capital for example). "Sorry, ya have to pay at this gas station we'd rather ya didn't drain our oceans or destroy the environment...and yes there is a fine for illegal skimming."

Savage

 

[Liam Devlin]

AGreed, lots of good thinking going on in this topic. IIRC, in the MT-TNE universes the 3ktn Tukera Freighter (J4/1G) has no CG lifters, and is an USL hull. They were posted to C-class or better Starports runs across the Imperium. No CG lifters, no landing on worlds- an orbital only craft/ and even without USL, no CG to counteract the GG's pull.

gotta run now...

 

[trader jim]

you know....everyone should have no problems unless someone screwed with your computers....like LIAMS.....hhhmmmnnnn...just a few mor degrees......YES....thats it......

 

[trader jim]

you know....everyone should have no problems unless someone screwed with your computers....like LIAMS.....hhhmmmnnnn...just a few mor degrees......YES....thats it......

 

[Liam Devlin]

Originally posted by RichardP:
oops forgot,

several gas giants have large animals/plants drifting in the upper atmosphere and collisions are nasty - see the linkworlds adventure, and on in the Megatraveller Journel (No2 I think)

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Also the collision of the 400dtn fuel shuttle on the Arival vengeance with a TL-7 Frontier fuel harvester crossing Gushmege towards Strephon's Stronghold. is another Mt example. Sensors difficulties of the vessel skimming are also a hazard.

 

[Liam Devlin]

Originally posted by trader jim:
you know....everyone should have no problems unless someone screwed with your computers....like LIAMS.....hhhmmmnnnn...just a few mor degrees......YES....thats it......

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If'n it was you that sent that bug, TJ, ye've sunk to an all new low.