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Message from discussion SF Predictions that ain't funny anymore
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James Nicoll  
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 More options Jul 8 2000, 3:00 am
Newsgroups: rec.arts.sf.written
From: jame...@morse.uwaterloo.ca (James Nicoll)
Date: 2000/07/08
Subject: Re: SF Predictions that ain't funny anymore
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In article <8k7ncn$q9...@news.cs.tu-berlin.de>,
Sebastian F. Mix <cha...@cs.tu-berlin.de> wrote:

>-----BEGIN PGP SIGNED MESSAGE-----

>jsbass...@aol.com (Jordan S. Bassior) writes:

>>James Nicoll said:

>>>Take, for example, a 1 km rock in a faavourable orbit. Say
>>>we have an ion drive able to kick material out at 200 km/s.  Say we
>>>need a delta vee of 5 km/s to move the rock into orbit around Earth.
>>>Say we have a 1 gigawatt reactor for power. What's the maximum
>>>acceleration we can get out of our set up and how long will it take
>>>to do that 5 km/s delta vee?

>>I truly don't know, but ...

>>1) I was thinking more in terms of nuclear impulse propulsion for a rock that
>>big, and

>>2) Why do our asteroid miners have to select a "1 km" rock? Why not something
>>smaller?

        Very roughly a years worth of iron ore.

>3) Why the heck 5km/s? That's no "favourable orbit" by any stretch of
>the imagination. There are loads of rocks around that need much less
>deltaV to the Earth-Moon system. The lowest I remember having read
>about was 60m/s

        For an Earth intercepting orbit. You may have trouble getting
permission to aero or lithobrake asteroids on Earth.

        Heh. Although you could go to one of the NEOs, set up a
linear accelerator and fire metalic lawn darts at the Earth.
Say the window is open a week, a gigawatt generator will let you
fire off 500 tonnes a second so up to 300 million tonnes of
iron delivered.

        Hmmm. Make each lawn dart 10 tonnes, you can deliver
one lawn dart per 8 km^2 of surface. Pay people to report where
they came down. Then all you have to do is collect them and
deliver tham to market.
--
        "Sure, Len, just because something is old doesn't mean it's
engraved in stone. We know a lot more about entertainment now than they
did back then. Look at Lawrence Olivier! You think he was in any of
Shakespeare's original productions? No! They added him years later!"      


 
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