Re: Re: starship-design: Does a one-way mission need mining?

[TLG.van.der.Linden@tip.nl (Timothy van der Linden)]

To Kelly:

>>My arguement was the opposite for a one-way mission: Rather than taking
>>large and specialized mining equipment with us, we'd recycle some of the
>>easiest substances and take with us that what we can't recycle in its purest
>>form.
>>Recycling equipment would likely be little different from refining
>>equipment, and recycling has the advantage that it already has quite pure
>>materials to start with. (Metals are still pure, but merely a bit brittle)
>
>Recycling here and there would both have similar limitations.  Some things
>like pure metals (aluminum)) or certain plastics are simple to
>reprocess/recycle.
>Other substances (composites, alloys, chemical componds,)
>are very dificult to disassociate down to pure chemical stock or simpler forms
>and reprocess back to usable form.

True, so we should try to avoid these substances. This may mean shorter
durability and other undesired characteristics. Whether we should really
avoid them, will depend on how undesired the properties are and how heavy
the are to take with us, or how difficult they are to mine in space.

>So there, like here, its to
>difficult/expensive/massive to recycle; and synthasising replacements from
>freash ore is preferable.  (Often a reason why recycling projects here fail,
>or are kept runing only as show peaces.  Paper recycling is famed for that.)

I don't think we'll be harvesting wood at Tau Ceti though... So we'll have
to replace some things we take for granted here at Earth anyhow.

>Given the fairly easy to access and  rich sources of raw material in space,
>this would be even more desirable.  Even systems like air recyclers might be
>shut down in favor of electralesizing water to make replacement air.

Well, I don't know that much about lifesupport systems, but I wonder: When
air can be kept usable for a 5 to 10 year trip trough space, is it that much
harder to keep it usable for a much longer period?

>(Certainly thats less difficult then breaking down CO2 and safer then alge.)
>
>The other major question is which would weigh more or be more relyable;
>carrying enough pre processed ore for the mission journey, or carrying
>refining equipment.  Generally small ore processing systems weigh much less
>then the ore they process, but their may be a minimum effective size for some
>systems.  If you might need a ton of processe ore, but the processor costs you
>10 tons.  You carry the 1 ton (assuming its stable).

I agree, however if we need all kinds of ores, we'll spent a lot of time
searching for accessable mining places.

Tim