On 9 May 2015 at 12:10, David Jaques-Watson wrote:

>     Leonard wrote:
>     >(lithium hydroxide cartridges deal with humidity and CO2, and
>     activated charcoal deals with trace gases).
>      
>     How do you manufacture these at TL 5? And if you are on an airless
>     world, where do you get the materials, such as charcoal?

Well, they recycle well.

And you make charcoal from carbon in your biosphere.

Lithium hydroxide is made from lithium oxide & water. The lithium
oxide is found in rocks. And you can use sodium or potassium
hydroxide instead, just not as efficient.

Calcium hydroxide is *way* down the list and a lot more of a pain to
work with. But even it is doable.

All of these can be extraced from rocks. Doesn't take high tech.
Breaking the oxides down into the metals takes electricity, but that
isn't necessary.

The real limits on an "airless" world are carbon, hydrogen and
nitrogen. All tend to go away if you are that sort of planet. So
they'll want to grab every bit of those they can from visitors, and
hunt aggressively for any ice, ammonia or methane deposits created
impacts of cometary fragments and carbonaceous chondrites.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com