Path: utzoo!attcan!uunet!husc6!rice!uw-beaver!uw-larry!szabonj
From: szabonj@uw-larry (Nick Szabo)
Newsgroups: sci.space
Subject: Re: NSS Board membership
Message-ID: <96@beaver.cs.washington.edu>
Date: 23 Jan 89 02:16:25 GMT
References: <6145@thorin.cs.unc.edu> <1989Jan15.095906.18357@utzoo.uucp> <92@beaver.cs.washington.edu> <1989Jan18.043708.27547@utzoo.uucp> <93@beaver.cs.washington.edu> <5740@cbmvax.UUCP>
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Reply-To: szabonj@uw-larry.UUCP (Nick Szabo)
Organization: U of Washington, CSCI, Seattle
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In article <5740@cbmvax.UUCP> jesup@cbmvax.UUCP (Randell Jesup) writes:

>	There's one very valuable thing there: energy.

There are several ways SPS technology could go:

CASE 1: Greenhouse concerns, lack of good nuclear technology, and tolerance
of SPS transmission effects lead to SPS as a major source of electricity.

a. SPS could be built as per your scenario, with lunar materials.  
(Space Research Associates, with whom I participate, has done the
premiere studies for Space Studies Institute on SPS from lunar materials).
b. ELM, laser-launch, gas guns, etc. make Earth launch cheap. 
Pre-fabbing SPS's on Earth becomes cheaper than building expensive        
construction and living infrastructure in space.
c. SPS is built with asteroidal materials, which may provide better
quality materials for less delta-v to GEO.
d: We learn how to generate solar power near Mercury, or tap the
power of Jupiter's magnetic field at Metis (see previous discussion of
this by Dietz et. al.), and transmit the power back to Earth, more
inexpensively than generating and transmitting power from GEO.

CASE 2: Environmental effects and real estate required for SPS energy
transmissision prove too costly.

CASE 3:  Nuclear energy, fission and/or fusion, becomes safe and cheap,
obviating the need for SPS.

CASE 4: Greenhouse effect does not become a problem, and we learn to
burn coal without acid rain (we have reserves to last several hundred
years).  Again SPS is not needed.

The Moon only figures in one of these scenarios (1a).  To rely on that
scenario to build a $100+ billion lunar base, requires a long leap of
blind faith.

>	Asteroids are very far away (energy-wise)

Nope.  Some are closer to LEO and GEO, energy-wise, than the surface of the
Moon.

> and are unknown quantities for the most part
>(compared to the moon).

Because we haven't explored them.  QED.


Nick Szabo              szabonj@fred.cs.washington.edu