I think the advantages of O'Neil type colonies vs building civilization and industry on planetary surfaces are often not recognized. In space you can have whatever strength of gravity that suits the process you're performing, you can have 24/7 sunlight - at 1 AU from the sun that's over a kW of free energy for each m^2of collection surface, you can have temperatures of thousands of degrees using mirrors, and still have near absolute zero temperatures in the shade only inches away.You don't have to contend with a pesky atmosphere, and you don't have to battle that gravity every time you bring something in or take something out.Even the raw materials are available in the form of NEO's, a meteoroid just 50 meters in diameter masses over a 150,000 tonnes (at 2.5g/cc).
Since 1g gravity is required to long term habitation, the only acceptable location for permanent human presence in space is on space stations.
Quote from: DarkenedOne on 08/19/2011 06:13 pmSince 1g gravity is required to long term habitation, the only acceptable location for permanent human presence in space is on space stations. Prove it.
A lot of things in even fractional gee are far improved over zero gravity.There's no compelling proof I've seen that Mars gravity will be insufficient for long-term habitation.
What is there to prove? Unless a way to eliminate the negative effects of low or zero gravity on humans, then permanent human settlement on low gravity objects can be ruled out.The only way we know to counter eliminate these effects is by centrifugal force.
Quote from: Robotbeat on 08/19/2011 06:58 pmA lot of things in even fractional gee are far improved over zero gravity.There's no compelling proof I've seen that Mars gravity will be insufficient for long-term habitation.Wasn't the canceled centrifuge for the ISS supposed to settle this?
Planetary surfaces like Mars, definitely.
You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot),
you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet,
you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc),
the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.
All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
The surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.
Quote from: Andrew_W on 08/20/2011 01:09 amThe surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.This we won't know for sure until we go there with a pick and shovel.Mick.
Quote from: MickQ on 08/20/2011 01:13 amQuote from: Andrew_W on 08/20/2011 01:09 amThe surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.This we won't know for sure until we go there with a pick and shovel.Mick.I'm betting that, as would be expected, any heavy metal riches have sunk to the planets core.
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?