From: barry@netcom.com (Kenn Barry)
Subject: Re: Space, the final frontier
Organization: QQQCLC
Date: Sat, 2 Jan 1993 18:35:22 GMT

In article <1339@abb-sc.abb-sc.COM> ksm@abb-sc.abb-sc.com (Ashley) writes:
>	Over the hollidays I had the oportunity to speak with a person
>who is working on space station Freedom for LMSC, subcontracted to 
>McDonald-Douglas. I discussed all the various space tech plans here
>with him  (brought a lot of print-outs so I wouldn't mis-quote anyone)
>and then he  refered me to some folks at McDonal-Douglas. After talking
>with several  space engineers and physiscists there, I arranged one
>last interview with  someone at Rockwell International who specializes
>in railgun tech.

	I wish you had said something more specific about what the
railgun guy told you.

>	The ideas of mining asteroids, industry in space and railguns 
>as a cheap way to get there nearly got me laughed out of every office I
>visited. I'm not going to waste my time going into deatails here, but
>the  theories espoused here are full of holes and are basic flights of
>fancy.  The one of the engineers from  McD-D said "Tell those fools to
>go back to  reading analog". I don't know what this means but he
>assured me everyone  who espoused these ideas would.

	It's difficult to evaluate this without knowing more about what
you asked them. I can assure you there are many people at NASA
interested in ideas like industrializing space, railguns, laser launch,
etc. I work at NASA myself. That doesn't make me an authority on this
stuff, and I'm not, but it does mean I know a lot of NASA people, and
many are enthused about space industrialization. Of course there's no
grant money in these things; that cools a scientist's professional
enthusiasm :-). Of the topics we've discussed, I believe only railguns
attract any measurable support.

	I'm certainly aware of some of the practical difficulties in
these ideas. For example, I consider railguns, lasers and
cable-to-orbit as means of orbiting payloads from Earth, long-term
possibilities, at best. The engineering difficulties involved with all
three seem enormous. But, as others have noted, railguns have real
potential away from Earth (e.g., launching things from the Moon, or
altering the orbit of asteroids). More immediate solutions to the cost
of ferrying up payloads from Earth are possible, however. We are
working on a space plane, which should lessen the cost of launching
small payloads, especially crew. But the main solution is to get the
bulk of our raw material from out in space, so we don't _have_ to
bring it up from Earth.

	I don't know what their objection to asteroid mining is; so much
depends on what you asked, and how you asked it. Our theoretical ability
to bring metal back from asteroids seems unarguable, so I presume their
objections must have come down to cost.

>	In short, I consider anyone with a degree in astro-physics who 
>is working in these fields to be pretty damned knowledgeable and I 
>will take their word over any of the thoeries posted on the net any
>day.

	A good policy, in general. Though I hope your mention of
"astrophysics" was metaphorical, as that is a field far removed from the
questions we're addressing.

	Arthur Clarke has said that when an old and distinguished
scientist says something is possible he is almost certainly right, while
when he says something is impossible, he is almost certainly wrong.
Billy Mitchell, the army general who commanded US air forces in WW I and
who is the spiritual father of today's US Air Force, was court-martialed
in 1925 for insisting on the importance of air power, and ridiculed for
predicting a kind of air war that would become a reality only 16 years
after his trial.

	Argument from authority is always suspect. There's a guy,
Stanton Friedman I think his name is, who's big on flying saucers,
thinks they're space aliens. He's always identified as a "former NASA
scientist", and he did in fact work for NASA at one time, as an engineer
I think. But that doesn't make him a reliable authority on flying
saucers. I also know at least one rather senior scientist at NASA today
who takes flying saucers seriously, and there are probably others. I'm
not convinced :-).

	Science is a specialized business. I've discussed Einstein's
Special Theory of Relativity with physics PhDs who said, basically,
"gimme a break, I haven't looked at that stuff since I was an
undergrad".

	You're right not to trust the net. But you don't have to. Scarce
grant money notwithstanding, NASA has put out actual government
publications on space industrialization, space settlement, solar power
satellites, etc. Check with the Government Printing Office for details.
You can be inundated with more technical detail than you'll likely care
for, if you choose to look. Space industrialization is a controversial
topic, but not some kind of nut cult.

>	As for transmitting energy to the earth in the form of 
>"harmless" microwaves, I haven't looked into that, but I would suspect 
>that if the microwave is weak enough not to harm the environment, it 
>would not be able to carry a lot of energy. Does anyone *really* know
>about  this? I'm with Steve on this one, let's ask the tough questions
>and  see if it works.

	The idea is to use slightly defocused masers to transmit to
large "antenna farms" on Earth. The defocusing keeps the energy density
down to a few watts per meter^2, a safe level. Feedback would cause
automatic shutdown in the event the beam wandered. Transmission via
maser has been tested, and is exceptionally efficient, up in the high
90s, far more efficient than electrical transmission by wire. On paper,
solar power satellites look like far and away the cleanest way to
generate and distribute large amounts of energy ever imagined. The
problem is in what it takes to build the satellites. If such satellites
are built on Earth and launched, the cost of putting significant
generating capacity into space is prohibitive, and will remain so for the
forseeable future. The only way to do it is to build a support
structure in space: mines, factories, people. And that's the sticking
point. Startup costs are large, and the thing sounds as visionary as
Billy Mitchell's vision of the attack on Pearl Harbor sounded to the
judges at his court martial in 1925.

-  Nothing fails like success  -             Kenn Barry
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