Life & Temperatures on Titan

[DataPacRat]

If you visit Saturn's moon Titan, you can expect temperatures around -290 F. As best as I can figure from p430, this counts as a 'cryogenic environment', so a PC who wanders outside of a nice, warm dome without a heated suit would roll against HT every minute at -29, with the PC losing one FP (and then HT) per point of failure; implying an average survival time of under a minute. Given that I've found webpages suggesting that survival times at -40 F are on the order of 5 to 7 minutes, that seems approximately reasonable.

I'm looking to build the cheapest Titanian heat-suit I can manage, and am willing to apply Pulver's armor-building system from Pyramids 52, 85, and 96. Assuming a standard human wearer, and roughly no-superscience TL10, I've ended up with this; I'm having a hard time gauging is plausibility. Anyone care to comment?

** Basic Titanian heatsuit (150 lb wearer, TL10):
* Face: 0.7 sf
- Transparent Bioplas, DR 1, Fabric: 0.0105 lbs, $12.60
* Everything other than face: 20.65 sf. (Actually in pieces: feet, trousers, jacket, gloves, hood)
- Kevlar, DR 1 (vs pierce/cut, DR 0.25 vs crush), Fabric: 2.065 lbs, $41.30
- Total cost so far: $54. (Stylish: $216. Fashion original: $1,080.)
* Addons
- Sealed: $5*21.35 sf = $106.75
- Extreme Climate Control: $200, 1 lb
- Air supply, tiny tank (15 min): $50, 0.5 lbs
- Power Pack, C cell (18 hours): 0.5 lb
* Stats
- Total weight: 4.0755 lbs
- Total cost: $410.75 + $10 battery (or $572.75, or $1,436.75)

(And for less-cheap versions, all sorts of other options can be thrown in from the Pyramid articles or Ultra-Tech.)

I'm a little hesitant to go with that strictly as written, that a thin para-aramid bodysuit with an electric heater is enough; but maybe I can throw in some extra lingo, such as 'aerogel insulation'. (I found an article suggesting such suits could have 'trapped gas insulation 7.5 cms thick'

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Anyone have stats for Titanian strap-on wings? Or do I need to dig into 3e Vehicles' for, say, a muscle-powered engine, ornithopter drivetrain, and strap-on harness crew station?

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Anyone have any good numbers on how large a dome would be feasible in 0.138 G? (Stresses on the frame could probably be made a bit easier by keeping internal and external pressures the same.) UltraTech suggests at TL9+, something 2 miles wide and 1 mile high is feasible... and 3e's GURPS Mars suggests $25M per square mile.

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Anything I might be forgetting about, beyond what has to be worried about for colonies on more ordinary, airless moons? (Eg, I've already found a note that, on average, the lighting is about 1/3000th the lux of Earth, and I can use that table from High-Tech Electricity for vision penalties.)

[AlexanderHowl]

Titan is a cold climate, unsuitable for normal heat systems (extreme is for Antarctica, not Titan). A TL10 smart vacc suit is probably your best bet, though it costs $5,500 with a TL10 flexible helmet. Then again, $5,500 is 11% of starting wealth at TL10 and would likely be considered normal clothing on Titan (coming out of the 80% allocated for assets).

[DataPacRat]

Originally Posted by AlexanderHowl

Titan is a cold climate, unsuitable for normal heat systems (extreme is for Antarctica, not Titan).

The sidebar on Pyramid 96 p26 says that a sealed suit with "extreme climate control" provides temperature tolerance of "-459°F to 250°F", which is what I based the above heat-suit build around.

[Anders]

My main problem with living on Titan is the gravity. Humans really are adapted to 1 G, and living in a place with 1/7th the gravity... I foresee all sorts of unforeseen problems.

[DataPacRat]

Originally Posted by Anthony

The big problem for a suit able to handle supercool temperatures is that the flexible polymers we generally use for things like joints aren't flexible at cryogenic temperatures (and there probably aren't any options that work over the entire range of temperatures needed); the actual insulation and heating requirements aren't all that dramatic.

It's TL10; I'm willing to posit a variety of advances in material science. (If nothing else, there should be more than enough computer power to brute-force through potential manufacturing paths.) Eg, having the suit made of clusters of atoms that gradually change in distributions between the inner and outer surfaces. Or some approach I'm not thinking of; any suggestions?

Originally Posted by Anders

My main problem with living on Titan is the gravity. Humans really are adapted to 1 G, and living in a place with 1/7th the gravity... I foresee all sorts of unforeseen problems.

I'm drawing on Transhuman Space a lot, given that it's one of the few reasonably-hard GURPS settings of close to the right TL. I've already posited something equivalent to the "calcium hack" used by THS's Duncanites. (Mostly because I'm already positing that Titan is populated, and I don't feel like forcing everyone to live in always-circling "gravity trains".)

I'm also positing that Luna has also been colonized, and so most of the solutions the Loonies came up with to deal with gravity got imported to Titan essentially wholesale. (I'm currently skimming through a pile of PDFs of '90's-era magazines from the "Moon Miners' Manifesto" with all sorts of such ideas; the most entertaining so far of which, if not the most practical, is building airlocks in the forms of shallow, U-shaped tunnels filled with mercury, kept liquid by weak heat-lamps.)

There are a few exceptions, such as Titan's atmosphere providing a terminal velocity. For a character in the classic sky-diving position, belly-down and limbs spread, their terminal velocity on Earth is around 120 mph; on Titan, I estimate it at around 37 mph. Which, according to Basic p430, implies a top falling damage of about 4d; or half that if falling into a lake or other soft surface. That's practically survivable even without a parachute or other protection, which has interesting implications for air travel.

Say, anyone have any thoughts on how small and light a parachute a typical human PC would be able to get away with, on Titan?

[dcarson]

Long term affects of low gravity are debatable. We have data points regular, 0 and 2.5 gravity. Turns out 2.5gs is good for chickens. The funding to co-fly a centrifuge with ISS has never been approved sadly.

[Donny Brook]

Originally Posted by AlexanderHowl

Titan is a cold climate, unsuitable for normal heat systems (extreme is for Antarctica, not Titan). A TL10 smart vacc suit is probably your best bet, though it costs $5,500 with a TL10 flexible helmet. Then again, $5,500 is 11% of starting wealth at TL10 and would likely be considered normal clothing on Titan (coming out of the 80% allocated for assets).

All characters get free basic clothing. This is regardless of whether they have 80% of wealth allocated to a settled lifestyle under the optional 80/20 split for starting wealth.

[DataPacRat]

Anyone have a clue on how deep a borehole could be dug with non-^ TL10?

The current best model of Titan posits a liquid-water ocean about 75 km down, and presumably there'd be at least one exploratory tunnel, if it's feasible. (There don't seem to be any resources worth digging that deep for, that I can find.)

Here on Earth, we made it about 12 km down before the rocks got so hot they became too melty to drill through, but Titan's a lot colder - of course, its surface 'rocks' are actually mostly water-cooled ice.

I thought GURPS: Alpha Centauri's thermal boreholes might have some relevant numbers, but didn't find any; ditto Pulver's article in Pyramid on red mercury.



In case you're curious, here's my current notes on Titan's layers:
- Surface, 150 kPa, 94 K
- 2500-2573 km: Decoupled shell of normal ice (type 1h), somewhere within the bands ~0.15-200 MPa, ~170-270 K
- 2100-2500 km: global subsurface ocean of salty liquid water and ammonia, ?at least 200-500 MPa, ?170 K+
- 1700-2100 km: high-pressure Ice (type VI), ~0.5-2 GPa, ~170-355 K
- 1300-1700km: Hydrous silicate core, ~500-800 K
- 0-1300km: Anhydrous silicate inner core, 900-1275K
- ? 0-500km: iron-rich core

[Anthony]

Originally Posted by DataPacRat

Anyone have a clue on how deep a borehole could be dug with non-^ TL10?

If you're digging through ice, you can probably drill through the crust to the underlying ocean by just melting your way through and relying on water pressure to prevent your hole from collapsing. That doesn't work on Earth because our instruments don't like liquid rock and other substances we can fill the hole with have much lower density than rock, but it shouldn't be much of a problem on Titan (you'll need continual energy to prevent it from freezing up again, but not very much, ice isn't a terribly good thermal conductor).

[DataPacRat]

Originally Posted by Anthony

just melting your way through

That'd do it. :)

Next up - coming up with a Ghost-computer-running submarine that can handle around 3,400 atmospheres of pressure (sphere, extra-heavy frame, and for a SM+2 ship, call it 1,000 DR)... and figuring out what all is there to be found, aside from mind-bogglingly massive amounts of salty water-ammonia. (Close to 20 times the volume of all of Earth's oceans, and the typical depth is 35 times the Mariana Trench's maximum.) I'm not really sure if Titan's geology leans towards the existence of hydrothermal vents, or any of the CHON compounds up on the surface would be found deeper below.

Still, even if organic life is infeasible, it could be a place for AIs and Ghosts who just want to get lost. After all, even the most expensive sonar systems in THS's Under Pressure only have a range of 30 miles, which isn't much compared to the 400-mile depth of Titan's subsurface ocean.