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

[Kelly St <KellySt@aol.com>]

In a message dated 12/20/97 7:21:47 AM, TLG.van.der.Linden@tip.nl wrote:

>Kelly,
>
>>>>Oh, I was thinking of fuel minning.  If you want to manufacture things
from
>>>>local resources, you'll need to do some ore refining.  Since you'll need
to
>>>>do more of that for a 1-way mission, you can't save any weight by leaving
>>>>that stuff off.
>>>
>>>?? At most we'd need to rebuild the starship. That still is a lot less
>>>material than the fuel. Actually we'd need much less than the whole
>>>starship. Likely most mass of the ship (engine structure, shield, hull,
>>>wall) does not need to be rebuild. That fraction of the mass left could be
>>>stored in a refined but raw form onboard the ship. So not much mining would
>>>be necessary.
>>>(BTW the heavy parts likely are metal, I believe metals can be quite easely
>>>recycled.)
>>
>>The mass to be processed would be greatest for the fuel, but I was refuring
to
>>the mass of equipment you'ld need to bring along for a 2-way vs 1-way
mission.
>
>So was I.
>
>>A 2-way mission requires fuel minnig and processing equipment.  It and a
1-way
>>mission also require ship repair systems, and the spare parts, materials,
and
>>mining and refining equipment for that (i.e. unrelated to fuel processing).
>>The second catagory of equipment and supplies would need to be greater for a
>>1-way mission given its much greater length.
>
>Indeed you'd need more to repair more, but would you need to do that much
>more mining? I was argueing that several materials could be easely recycled
>and those that couldn't be recylced would not necessarily need to be mined,
>but could also be stored on board in raw but refined form.
>
>>However the 2-way mission
>>requires far more fuel mining and processing equipment.  A 1-way probably
>>could save some weight by procesing simple ores (space has extreamly high
>>grade ores floating around in it), and manufacturing somethings from that
>>rather then stored raw materials, but in most cases that wouldn't be
critical.
>
>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.  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.)

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.
(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).


>Timothy

Kelly