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

blogs.scientificamerican.com

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

#141

Post by PeterisP »

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.

Mass change of human behavior is one option for solving climate change, but IMHO doing that takes much, much more coordination and effort, and is less likely to succeed than a "apollo project" to launch a lot of foil pieces / chaff in proper orbit to achieve a slight shading of the sun.

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

#142

Post by acheron »

jessaustin wrote: post #95
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.

The ultimate weapon of imperialist terror! Why haven't we built this already?! "It's most unfortunate, and not only for your farmers, that you've chosen not to have sunlight this year... perhaps you should reconsider our demands?"

Ian Fleming’s James Bond in Sunlight is Forever

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

#143

Post by siffland »

Serious question, since this is out of my swim lane. The Author keeps talking about the effects of Galactic Cosmic Rays, do we have any usable materials we can build habitats out of that can block them? I mean usable in the sense we can produce in scale and they are non toxic to humans.

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

#144

Post by openasocket »

muzani wrote: post #33

> It’s cold on Titan, at -180°C (-291°F), but thanks to its thick atmosphere, residents wouldn’t need pressure suits—just warm clothing and respirators. I'm no space colony expert but am I missing something here? -180°C sounds like constant space suit level, not "just warm clothing".

Yeah that confused me too. You'd definitely need your suit to be watertight (or rather liquid-methane-tight) so that the liquid doesn't touch your skin to prevent immediate frostbite. Maybe you won't need a fully pressurized suit, but that's just so low I feel like you wouldn't be able to survive for long periods without some sort of active heating (i.e. walking around with a portable furnace).

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

#145

Post by PeterisP »

muzani wrote: post #39
keiferski wrote: post #28

Earlier quoted context omitted.

> Mainly because right now, any significant endeavour is tied to using massive amounts of fossil fuel. But does that actually matter in space? I am asking out of genuine curiosity here: does using fossil fuels in space have any real downside? There is no atmosphere, ergo no greenhouse effect. The vastness of space would seem to swallow up any sort of pollution.

That's... a different question. Where would you find fossils on other planets? The article says Titan has seas of hydrocarbon, but otherwise Moon and Mars, it's just not an option. One reason why Musk has invested so much in non-fossil fuel tech is not so much to save this planet but to operate things on other planets.

You can manufacture burnable 'fossil' fuels (usually from water and co2) using solar energy. We don't do that on Earth much because it's simpler and cheaper just to mine it.

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

#146

Post by perilunar »

3solarmasses wrote: post #129
tantalor wrote: post #119

Earlier quoted context omitted.

The article is about human colonization, so Fahrenheit is more appropriate unit because it represents human compatible temperature ranges better than C or K.

Exactly. Very few people get this. Fahrenheit is better for communicating temperatures in daily life. Plus we can be more precise in our language due to the expanded scale. e.g. We can say 62 degrees F, rather than 16.6667 degrees C.

Absolutely. Those of us outside the US have terrible trouble with temperatures. We're constantly confused. Just the other day I was trying to measure something to a tenthousandth of a degree and I said to my friend "I wish we used Fahrenheit — they only have integer temperatures".

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

#147

Post by rbanffy »

aaron695 wrote: post #131
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…

> floating cities We have decided on Mars, can we stop forking it. Have we learning nothing from Linux? But if you have to, could you hurry up and make a floating city on earth to practice ? People would pay a tonne of money for that, and having floating cities (In reality small communal groups, so more a village) would be very very neat.

> make a floating city on earth to practice?

Earth's atmosphere is lighter than the Venusian one at that altitude. A balloon filled with breathable air would float naturally. You can't do that on Earth.

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

#148

Post by TheGallopedHigh »

siffland wrote: post #143

Serious question, since this is out of my swim lane. The Author keeps talking about the effects of Galactic Cosmic Rays, do we have any usable materials we can build habitats out of that can block them? I mean usable in the sense we can produce in scale and they are non toxic to humans.

One of the simplest methods would be to bury habitats in conjunction with materials to block cosmic rays.

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

#149

Post by ryanmercer »

siffland wrote: post #143

Serious question, since this is out of my swim lane. The Author keeps talking about the effects of Galactic Cosmic Rays, do we have any usable materials we can build habitats out of that can block them? I mean usable in the sense we can produce in scale and they are non toxic to humans.

Any material will work if thick enough. Thick concrete, water/ice. It just has to be thick enough to also handle the secondary radiation from higher energy stuff. We're talking a need for several feet of concrete or several inches of lead.

For a rocky body like Mars the 'easiest' solution is simply excavate trenches to put your habitats in and then piling several meters of regolith over the top, or using lava tubes/caves. If excavating was too difficult you could similarly just make bricks of compressed/fused regolith and pile them up. Titan has a rocky core but is mostly ice where a manned mission would be, there you'd probably just carve out large blocks of ice and place them around your habitat.

The best universal solution would probably be some sort of sandwich of materials that was still decently thick.

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

#150

Post by state_less »

garmaine wrote: post #49
state_less wrote: post #42

Let's colonize LEO. You get radiation protection from earth's magnetosphere. You get zero G for funsies. You get a new perspective on earth and interesting new kinds of manufacturing. It's not too far away, so you can get there and back in a day. It's far enough in space that you need to improve your closed cycle systems. You might survive a number of different cataclysms. It seems like a good stepping stone.

> You get radiation protection from earth's magnetosphere. Only in very specific orbits (NOT the ones we are currently using, btw.) The Earth's magnetosphere actually captures dangerous radiation and various anomalies in the belt distribution cause portions of low-Earth orbits to be irradiated. > You get zero G for funsies. And the medical issues. > interesting new kinds of manufacturing. There are a handful of (very…

I'm not trying to take the wind out of the sails of any vehicles going elsewhere, just think LEO is a good place to start. Something like, before crossing an ocean, let's cross the Florida straits over to the Bahamas.

> The Earth's magnetosphere actually captures dangerous radiation and various anomalies in the belt distribution cause portions of low-Earth orbits to be irradiated.

Pick the favorable orbits. We have data on our ISS astronauts. Seems like we can go years up there if we wanted.

> And the medical issues.

Most folks are going to want to go up for a few weeks/months and then come back to tell the tale. A habitat might employ centripetal acceleration. Anyhow, I think medical issues will be manageable. I suspect there are a few orders of magnitude more people who are interested in a vacation in space or work from space scenario than a long distance voyage to the moon or mars where you are cut off from the home world and have a big latency cost on communications.

I think this is about filling rockets with large sums of cargo to keep the space business growing. If a starship can be made for $5 million, there are plenty of yachts just down the coast from Cape Canaveral that cost more than that. If you could give folks a stay in LEO for ~$50k, there will be plenty of people who can afford that. I bet you could find tech companies that would let you work remotely from space as a signing bonus.

> There are a handful of (very interesting) crystal manufacturing that requires zero-g. These could be done in automated or human tended LEO or LLO manufacturing labs. You don't need a large human presence.

Agreed, I'd add that this isn't so much about keeping the number of people down, but increasing the demand for people to go into space. I'm excited about the side effects it will have for technology and science.

> To the downsides, LEO lacks any resources whatsoever, and still has a nontrivial delta-v to the rest of the system. All your arguments in favor could be applied to the Moon, which does have LOTS of resources and better radiation shielding.

The moon and mars are good places to settle too. I'm only arguing that Earth LEO is easier to start with because Earth has more readily available resources than any of the other locations. LEO is still hard enough where we'll have to improve our ships and space quarters for design and comfort. So I think it's a good stepping stone.

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