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Saturn's largest moon may be the only place beyond Earth where humans could live

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Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#231

Post by hutzlibu »

Aardwolf wrote: post #226
hutzlibu wrote: post #155

Earlier quoted context omitted.

Venus has the very big advantage of having allmost earths g. That is a big deal. The very big disadvantage except the atmosphere is the lenght of a venus day: 116 earth days and 18 hours. So a science fiction solution is asteroid bombardment to make venus spin faster ..

Day length seems less of a concern than the temperature and resources issues (since you can use artificial lighting), plus you can float around in the balloon to choose to be in a light, dark, dusk or dawn place, and even enjoy an eternal sunset. This almost sounds like it would fit Le Petit Prince

The floating cities are surely a way to circumvent the daylength issue. But the daylength is directly linked to the temperature - even if you could normalize the atmosphere, the day side would still get just too hot and the nightside too cold.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#232

Post by btkramer9 »

NortySpock wrote: post #229
btkramer9 wrote: post #222

Earlier quoted context omitted.

The only thing going for the moon is its proximity to Earth. Mars has more than double the gravity of the moon, an atmosphere, nearly earth-like day night cycle and satellites have a much easier time orbiting mars

The moon has water ice in dark craters, as well as minable ore that contain aluminum, iron, silicon and oxygen. You will "just" need to use heavy mining and smelting gear to extract it. Solar power and batteries should work assuming you're willing to build your base among the "peaks of [near] eternal light" which get sunshine nearly ninety percent of the time.

This is mostly true on Mars too except perhaps the eternal light part

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#233

Post by btkramer9 »

theseadroid wrote: post #224
btkramer9 wrote: post #222

Earlier quoted context omitted.

The only thing going for the moon is its proximity to Earth. Mars has more than double the gravity of the moon, an atmosphere, nearly earth-like day night cycle and satellites have a much easier time orbiting mars

And its proximity is probably the most important factor?

I'm not so sure about that. It takes more delta-v to get to the moon than mars and both are still too far for immediate response to emergencies. Sure the moon has the advantage of emergency assistance of a few days (?) but I don't think that's more valuable than all of Mars's pros

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#234

Post by stagger87 »

vl wrote: post #134
JoeAltmaier wrote: post #127

Earlier quoted context omitted.

Ha! Though actually you can't eat on top of Mt Everest. Your digestion stops moving at the previous base camp.

But why? Due to low air pressure? McDonald’s obviously will be pressurized.

The previous comment is wrong. Not only can you eat at those elevations, but you have to eat. Yes, your body is shutting down, and that includes digestion. You won't want to eat, but you have to force yourself to. Most people eat high carb, high calorie foods on summit day. Your body is burning a lot of calories at high elevations, and you have to replenish them. Your body shuts down faster if you don't regularly eat.

There are lots of accounts and theories about the best foods to eat at these elevations, they are easy to search online. Search for high-elevation diets, or "foods to eat on summit day".

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#235

Post by btkramer9 »

rbanffy wrote: post #170
Dumblydorr wrote: post #118

Earlier quoted context omitted.

Mars is definitely the easiest place to colonize, by far. It's much closer than the gas giants, there's no craft capable of taking people to Saturn even devised, let alone constructed. Meanwhile, we have SpaceX actively building a rocket for Martian colonization. Second, the Venusian atmosphere is oppressive as hell, you'll not be solving that problem anytime soon, as we can't even solve Earth's much easier atmospher…

> SpaceX actively building a rocket for Martian colonization. It's unknown whether it is capable of protecting the human cargo on its way to Mars. Maybe a design with habitation encased in the propellant tanks is a better idea for longer transits. In any case, Starship is well positioned for Earth and Moon travels, as well as for sending equipment to LEO and the Moon.

Worst case radiation they'll receive is comparable to if they've been smoking cigarettes the whole trip. That's pretty damn good if you ask me

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#236

Post by stromgo »

mannykannot wrote: post #204

Am I missing something here? "On the surface, vast quantities of hydrocarbons in solid and liquid form lie ready to be used for energy. Although the atmosphere lacks oxygen, water ice just below the surface could be used to provide oxygen for breathing and to combust hydrocarbons as fuel. " [my emphasis.] They are proposing splitting water to get oxygen for burning hydrocarbons to produce energy - but splitting water…

I'll answer the energetic question. Splitting water produces oxygen and hydrogen, so with our oxygen we have the choice between burning hydrogen or burning Titan's hydrocarbons. Burning the hydrogen would bring us back to square one, so the question is whether burning hydrocarbons yields more energy than burning hydrogen. It appears to not be the case. Some numbers I found online:

  burning 1 mole of O2 with hydrogen yields 572 kJ
  burning 1 mole of O2 with methane yields 444 kJ
  burning 1 mole of O2 with butane yields 443 kJ
  burning 1 mole of O2 with octane yields 437 kJ
  burning 1 mole of O2 with glucose yields 467 kJ
https://personal.utdallas.edu/~metin/Merit/MyNotes/energySci...

https://www.ausetute.com.au/fuelenergy.html

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#237

Post by jccooper »

TheOtherHobbes wrote: post #165
keiferski wrote: post #31

Two thoughts on this topic: 1. The film Gattaca (1997), in addition to being an excellent, inspiring film all around, centers on an aspiring astronaut's upcoming trip to Titan. Highly recommended. - https://www.youtube.com/watch?v=lZa83dTf4JA 2. The colonization of Venus is also a fascinating idea that isn't talked about much in comparison to the Moon or Mars. Essentially, the surface is too hot for colonization, but…

Unless you're planning to build a literal castle in the sky out of convenient gasses, this is completely unworkable. Even at that altitude the cloud layer is still very turbulent and very toxic, and no structure will be absolutely gas-tight. And if the temperature is 75 °C outside, it's going to take insane amounts of energy to keep the inside of your hab cool - especially if it's made of metal and not rock. (A thin…

There are perhaps ways to mine Venus surface materials; something like dredging. Dedicated development of high-temp computing may also make longer-term robotic operations possible. None of that's particularly convenient, of course, and I can't imagine why you'd want to do it. But one can say that about every other extra-terrestrial option, too.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#238

Post by gpm »

lolc wrote: post #87
101404 wrote: post #74

Earlier quoted context omitted.

Stopping climate change isn't even hard, just place a large solar sail on a sun synchronous orbit to block part of the sun's energy from reaching Earth.

Now I'd like to know what you consider hard if launching a solar sail is not.

Colonizing mars. It takes more mass and the mass has to be "smart" instead of just some dumb sails with some station keeping thrusters attached.

This is actually one of the best reasons to support SpaceX in my opinion. They are doing the R&D needed to provide a viable solution to global warming at a reasonable cost as a positive externality.

Source on sun-shade working at 20 million tonnes - https://en.wikipedia.org/wiki/Space_sunshade

Sources on SpaceX intending to be able to launch far Cargo than that every year (note: I'm lazy so I didn't find a source that did the multiplication of 100,000 tons * 1000 ships for you): https://www.cnbc.com/2020/03/09/spacex-plans-how-elon-musk-s...

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#239

Post by btkramer9 »

rootbear wrote: post #230
beefman wrote: post #201

The dangers of radiation on Mars are greatly exaggerated. The dangers of low gravity on Titan and elsewhere are greatly understated, as is the immense distance between Mars and Titan. A floating habitat on Venus is harder and less attractive in every way than a rotating space station, which is clearly our next milestone in space. In terms of planets though, there's a reason Mars gets the most attention: it's obviousl…

I, too, have concerns about how well humans will thrive in low gravity (the moon, Mars, etc). Over time, we could evolve a branch of humanity, "Homo ares", for Mars, but it won't be easy. Venus is just a tragic waste of a planet. So close to Earth in size, so wrong in every other way.

I've always wondered if Venus was as habitable as Mars on the surface which we'd choose. The lower gravity well of Mars makes it much easier to come back from which is practically a requirement to go there. But like you said, the jury is still out on how well we can live in lower gravity.

Getting back from Venus after just beginning to colonize it may not be possible with current technology.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#240

Post by JdeBP »

tantalor wrote: post #120
Symmetry wrote: post #79

Earlier quoted context omitted.

I think colonizing the Moon is a good idea must mostly just the south pole to start with. On most of the Moon you have 2 weeks of frigid darkness you where you're living off batteries followed by 2 weeks of intense sunlight. At the peak of eternal light at the south pole you can just slowly turn your solar array 360 degrees over the course of a month and have (nearly) continuous power. There's a big difference betwee…

> slowly turn your solar array Sure that's nice but the angle of sunlight is very low so you are limited in that respect, e.g,. available surface area.

Then do not turn the array and do not put it at the pole.

Build a ring of static solar collectors at some respectable km distance out, such that some will always be in sunlight, and transmit the power back. It brings up the engineering challenges of high-voltage power transmission in low gravity, zero atmosphere, and various forms of radiation (e.g. how far apart one could place pylons); but I suspect that these are more likely solvable than some of the things that futurist ideas bring up. (As yet uninvented, or not manufactured in large quantities, materials with really high tensile strengths, for example.) And it avoids the problems (construction and maintenance) of continously moving large numbers of solar panels around in a vacuum. It even introduces redundancy.

Moreover we definitely already know how to cope with an electrical power grid where only some of the generators are currently supplying power. (-:

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