A reason to go to Mars

From: Marcel

> Mars has the soil to easily protect human habitats from cosmic
> radiation and the water (derived from ice) to protect pressurized
> biodomes from cosmic radiation. The Martian environment has all of the
> chemical elements essential for human survival.

I still say that an orbital habitat built next-door to a well-selected NEO would have all of the chemical elements available to it as are available on the surface of Mars.

> And the gravity Mars
> should be significant enough to keep people physically fit on the
> surface.

We don't yet know this for certain. This is simply an oft-repeated assertion from Mars advocates, but they believe this because they have to.

The beauty of the notion of spinning for gravity is the flexibility afforded. If it turns out that we've been far too pessimistic, and gravities of 1/3 or even 1/6 are perfectly alright, then we can enjoy smaller-scale habitats at an earlier point than we might otherwise anticipate. But if it turns out we've been far too optimistic, and any gravity below 1 G results in health problems, then we simply engineer for that. The settlement program need not be hopelessly derailed by bad news on the gravity/health front.

> Mars also has two tiny moons (Phobos and Deimos) which are probably
> captured asteroids. These could be mined for oxygen, hydrogen, and
> platinum.

As could any Near-Earth Asteroid (NEA), with a round-trip delta-V far less than for any object orbiting Mars.

> The soil and rocks from these tiny moons could also provide
> radiation shielding for small manned habitats orbiting the Earth,
> Moon, or Mars.

Orbiting Mars, I have no doubt. But for any platform in cislunar space, the moons of Mars would be uncompetitive sources of raw material. They orbit inside the gravity well of Mars (Phobos, very deeply inside). This means the gravity of Mars adds a significant levy to the charge of transporting material. Especially if we're only talking about radiation shielding, the moon is the most economical source of raw materials.

> And there's also enough material to provide shielding and structural
> material for the first large rotational space habitats. So the first
> space colonies might get their building material not from the
> asteroids, or the lunar surface, but from the moons of Mars.

I think the only way raw materials from the moons of Mars will get used to build orbital habitats is if someone wants to build them in high orbit around Mars. And the only reason I can think of to build habitats in high orbit around Mars would be if someone wanted to teleoperate some operation on the surface, but wanted to live under more Earthlike conditions while doing so.

I have heard people say perhaps O'Neill habitats will get built in orbit around Mars to house the people overseeing the terraforming operations on Mars. But I think if one allows for the possibility of O'Neill habitats at all, terraforming becomes completely irrelevant.

Regards,

Mike Combs