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Comment by IntemerateApe | Hacker News Reader

in Delta-V - one character goes on a rant about how Mars is pretty much a dead end. Does anyone know how true this is?

Mars will certainly be challenging to colonize, but it has some major advantages that I believe outweigh the disadvantages.

First, water is pretty abundant almost everywhere on Mars.

Second, carbon is abundant and nitrogen is abundant enough to make food and plastic production viable.

Third, Mars has an atmosphere which is thick enough to provide some protection from radiation and meteorites but thin enough that conductive heat loss isn't too big of a concern. Also, aerobraking massively decreases the amount of fuel required to get to Mars.

Fourth, Mars probably has enough gravity to prevent most of the health risks associated with low gravity.

I don't think either Mars, the Moon, or asteroids are dead ends for colonization. In the long, long run I think more people will live in rotating habitats in cis lunar space than on Mars, and more people will live on Mars than the Moon, but I think there are enough resources for millions or perhaps billions of people to live on Mars.

What Mars lacks is a source of power. The solar incidence may be too weak to support much of anything. No fissile materials have yet been discovered there.

The Moon has plenty of solar to harvest.

> What Mars lacks is a source of power. The solar incidence may be too weak to support much of anything.

Says who? The solar constant on Earth is about 1360 W/m².

Due to the atmosphere, only about 1025 W/m² actually get to the surface.

Mars, just from applying the inverse-square law has an average solar constant of about 589 W/m². Due to the lack of clouds and thin atmosphere, most of that reaches the surface.

So basically you get more than half the energy per unit area than on Earth. Coupled with batteries or power-to-gas and even wind power, I see no major power problem on Mars.

It's not as if there's a lack of usable land for solar arrays or big stacks of batteries on Mars...

The battery issue really cuts against most places on the Moon. Getting through 12 hours of night is a lot easier than getting through 2 weeks of night. There is the peak of eternal sunlight on the Moon's south pole where the sun marches around the horizon forever[1] but the lunar night is a big challenge everywhere else.

[1] And right next to an eternally shadowed crater we know has hydrogen, probably in water.

I haven't read the book and maybe the argument is solid, but I'm inclined to disagree. For mining, maybe Mars isn't the best place (hoisting stuff out of the gravity well might not be worth it except for high-value metals), but on the other hand it has decent gravity and an atmosphere, which means it's more suitable for human habitation and fuel processing than the asteroids. And living on a planet has a certain appeal that living on a ship doesn't.

In the far future we might have better habitats in the asteroid belt than on Mars, but that's pretty far out. In the medium term, I expect Mars will be an important fuel stop at the least.

I guess there'd be a kind of a self-perpetuating economic force at work: mining would be most lucrative when the products can be consumed near where they're made, and if there's a heavy demand for construction in the asteroid belts then the asteroid belts are where most of the materials will come from. If it's on Mars, then the materials will be gotten on Mars. (That's assuming that material shipment is expensive. On the other hand, if you can mine iron in the belts and then just lob it at Mars with a rail gun and have the Martians drive out in rovers to collect the splatters of molten metal off the surface, then maybe the economics of non-local mining can work out.)

Mars might not be worth the effort if you have good asteroid mining - you could say build a O'Neil type cylinders inside an asteroid from local resources and spin them up. Some of the Tech you need for mining might transfer directly into tech or building structures like this. For instance refining metals in zero-G via rotating smelters to separate materials might serve as system to spin up and control the cylinder rotation.

You might even get most of the stuff aside from metals as byproducts of the metal refining process (water, oxygen(from oxids) and carbon mostly). Nitrogen and Phosphor might need importing.

Most of the leftover asteroid serves as Protection against small collisions.

If water/oxygen/carbon are readily available, I guess that would go a long ways towards making asteroids self-sufficient. On the other hand, if they're available but one can only extract a small amount at a time as a byproduct of mining, then Mars might still be pretty attractive where those things are available in inexhaustible quantities with low effort.

I'm assuming that huge amounts of methane (or other suitable fuel) and oxygen will be wanted for propellant, though maybe ion propulsion makes that less essential.

Mars is a good training ground as it does provide you something (gravity, abundance of resources), but after we're reading to take off the training wheels, moving enough resources from Earth to Mars to build a civilization is almost the same as moving the resources to ... not Mars - keeping them in space, in (probably rotating) space stations, and moving the whole station around to wherever the resources you need are (sunlight, water, carbon, metals, ...)

I’m not familiar with the contents of the rant but I don’t think anyone can know how well Mars colonization would go.

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