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

[Kelly St <KellySt@aol.com>]

In a message dated 12/29/97 10:31:16 AM, TLG.van.der.Linden@tip.nl wrote:

>>>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.

True, but that might not be possible.  For example: Lab chemicals, industrial
maintenence/clening chemicals, medicines, IC chips, etc would fall into the
complex chemical and alloy catagories.



>>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?

Depends on what it takes to do the recycling?  Could be the equipment would be
harder to keep runing then the equip needed to split water.


>>(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.

True, but the need for ores should lessen dramatically with shorter mission
times.

>Tim

Kelly