[ExI] META: List Over Posting

[Natasha Vita-More]

Please watch the number of posts.


Thank you.


Nlogo1.tif Natasha Vita-More

-----Original Message-----
From: extropy-chat-bounces at lists.extropy.org
[mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of hkhenson
Sent: Friday, May 01, 2009 4:51 PM
To: ExI chat list
Subject: Re: [ExI] Power satellites

At 12:30 PM 5/1/2009, Ben Zaiboc wrote:

snip

>OK, I'm way behind on this list, so someone may have asked this 
>already, but I'm interested in the issue of NEOs as a source of raw 
>materials, and whether this is even remotely feasible.

Sure.  A reasonable mass budget for a processing plant is ~50,000 t or 5
million kg.  At current launch prices, it would cost $1000 billion just to
launch it.

>I'm thinking NEOs, like most things in space, go fast, relative to the 
>earth.  Really fast.  Getting to them, extracting useful resources and 
>getting back with those resources isn't at all like drilling for oil or 
>digging up metal ore here on earth.  I suspect it's possible that the 
>energy required to get there and get the hydrocarbons or ores or 
>whatever back, would far outweigh their value.

>Anybody know some hard facts about this?

In the context of a power sat construction project that is using a million
tons per year of materials, it's just a matter of delta V and payback time.
For example, GEO and asteroid 1986 DA are only 140 m/sec from each other.
If the processing plant was turning out 2% of its mass per day, in say
Invar, it would take 50 days for the investment in the processing plant to
repay its mass.

Simple math.

It does take some design thought.  My suggestion is an open ended induction
furnace where the metal is drawn off in a fast moving rod.

Keith 

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