home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Space & Astronomy
/
Space and Astronomy (October 1993).iso
/
pc
/
text
/
spacedig
/
v15_1
/
v15no122.txt
< prev
next >
Wrap
Text File
|
1993-07-13
|
36KB
|
762 lines
Date: Tue, 18 Aug 92 05:10:09
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #122
To: Space Digest Readers
Precedence: bulk
Space Digest Tue, 18 Aug 92 Volume 15 : Issue 122
Today's Topics:
ACRV/Soyuz P # of Passengers
Deep-sea Diving on Europa
Early Warning of missiles and meteors
Energya and Freedom and Soyuz ACRV and... (2 msgs)
Global Positioning System (GPS)
Private space ventures (2 msgs)
REQUEST: Mars face gif
Seeking SSF payload user requirements
SPS feasibility and other space development
SPS fouling astronomy (long)
Star Trek (anti-)realism
Welcome to the Space Digest!! Please send your messages to
"space@isu.isunet.edu", and (un)subscription requests of the form
"Subscribe Space <your name>" to one of these addresses: listserv@uga
(BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: 17 Aug 92 15:06:41 GMT
From: Gary Coffman <ke4zv!gary>
Subject: ACRV/Soyuz P # of Passengers
Newsgroups: sci.space
In article <1992Aug15.222003.751@iti.org> aws@iti.org (Allen W. Sherzer) writes:
>In article <_kbyx3j@rpi.edu> strider@acm.rpi.edu (Greg Moore) writes:
>
>> One poster sent me a message explaing partly why. It's typical for
>>contractors to underbid and ask for more money later.
>
>When the government is paying for hardware to be developed this can indeed
>happen. This can't happen when the government is only buying services. Like
>anything else, if the service is not provided, the contractor isn't paid.
The problem with this scenario is *the service isn't provided*. That
can't be tolerated when there are crews up there. So the government
*will* pay, and the contractor knows it. When salaries in the CIS
go up, and they will, what happens to the bargain Soyuz prices?
CIS space workers now make $12 a month. Assume their real wages only
go to $1200 a month. Since the bulk of *any* high tech operation's
costs are personel, figure on Soyuz per each prices climbing 100 fold.
Either that, or the CIS factories will start making toasters instead
of rockets.
Gary
------------------------------
Date: 18 Aug 92 02:02:30 GMT
From: Nick Janow <Nick_Janow@mindlink.bc.ca>
Subject: Deep-sea Diving on Europa
Newsgroups: sci.space
barrett@iastate.edu (Marc N Barrett) writes:
> My question is: do we have any deep-sea diving equipment that could survive
> the great pressures that exploration of the bottoms of the Europan oceans
> would entail?
I've been helping develop a new science fiction role-playing game, and both
Europa and Ganymede are the sites of colonies, so I've been looking into the
possibilities for both worlds. The figures I have for their ice and water
layers are:
Europa: 70km ice, 100km of water or slushy ice, then a silicate core of 1400km
radius, heated by radioactive decay and tidal friction (10% of Io's).
Ganymede: 100km ice, 400-800km water or slushy ice, then a silicate core of
1800-2200km radius.
Assuming that pressure is directly proportional to gravity, the bottom of
Europa's ice layer should have a pressure equivalent to Earth's ocean at around
10km. We have vehicles that operate that deep in our ocean. The bottom of
Europa's ocean might be equivalent to 25km of Earth's ocean. Whether we can
manage to send a manned vehicle that deep is up to some creative engineers. :)
Maybe a combination of scaling up present technology (thick-walled spheres) and
providing concentric layers of gradually decreasing pressure towards the
central manned chamber would manage it. Then too, remote vehicles are easier
to design and have a longer possible duration, so they could handle much of the
exploration.
I was wondering how deep humans could feasibly handle free-swimming, with
artificial blood oxygenation. I came across a comment about high pressures
distorting the shape of molecules, interfering with biochemical activity (the
proteins don't match up anymore), so there does appear to be a limit.
Europa (and many aspects also apply to Ganymede) should have had a deep ocean
for quite a while in its past, heated by radioactive decay, accretion heat,
tidal friction and heat radiated from Jupiter (I assume Jupiter radiated a lot
more in its earlier stages). There would probably have been a greenhouse
effect due to evaporated water, methane and ammonia. A nice warm, wet moon
with lots of geological activity might be suitable for starting life.
Life could have started there at underwater vents. Photosynthesis might not
have developed, due to the low light levels. Then again, maybe it was
efficient enough to compete with sulfide-reduction life, or whatever else there
might have been.
Another possibility is that Europa's life could have been based on radiation
from Jupiter's belt. The radiation levels might have been high enough to
provide a significant energy resource, ripe for exploitation. Perhaps the
radiation produces significant quantities of free radicals, without the help of
photosynthesis. Unfortunately, this form of life would probably have died when
the thick ice layer formed.
Is there any way to exploit the other radiation from Jupiter (decimetric,
decametric, thermal)? Maybe impurities along edges of ice formed antennas,
creating a weak electrical current, which powered a chemical reaction among the
organic impurities. If the resulting chemicals improved the ability to extract
energy...evolution? :)
Europa has lots of potential for speculation. Was there life on Europa at one
time? Is there life down there? Are there physical processes in the core,
ocean and ice that fractionate elements to commercially-valuable levels? Are
there "veins" of mineral-rich ice, formed by upwellings and slow freezing in
relatively low gravity?
...and of course the most important question of all: is Elvis there? :-)
--
Nick_Janow@mindlink.bc.ca
------------------------------
Date: 17 Aug 92 14:35:54 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Early Warning of missiles and meteors
Newsgroups: sci.space
In article <Bt1Fwn.It8@usenet.ucs.indiana.edu> turner@bigbang.astro.indiana.edu (George Wm Turner) writes:
>
>>In article <6202@ucru2.ucr.edu>, judson@watnxt2.ucr.edu (Michael Judson) writes:
>>
>>A friend and I were having a discussion as to whether or not the early
>>warning system used in detecting missiles can actually detect meteors
>>that pass through the Earth's atmosphere.
>
>i know that they can track anything larger than a softball in close
>earth orbit (70's technology, today maybe they can track metallic tennis balls.
>
[good discussion of radar fundamentals deleted]
>
>they could detect it; if their systems were looking. the military
>is rather sensitive about how sensitive their equipment is. they
>wouldn't brag about seeing a 5 inch nick in the theorized meteor
>nor would they admit that a 1 meter chunk of iron plopped down
>in the good ole U.S. of A. & they missed it. (they were probably
>looking for plane loads of marijuana anyway.)
The one thing missing from this radar discussion, and the key thing
from the standpoint of meteor detection, is the clutter suppression
systems used on these radars. Because these strategic radars have
the mission of detecting incoming hostile missiles or aircraft, and
because there are thousands of sources of radar returns, the systems
are designed to automatically suppress returns that don't match the
threat profile. In particular they are set so that they don't report
objects travelling faster than an ICBM. Therefore a fast meteor will
not show up on the screens. If this were not done, literally thousands
of incoming threats would be reported per hour as small meteors were
detected. The raw radar data is too large to be permanently stored.
Only the filtered returns are committed to tape. So it's very likely
that the military has no record of this meteor.
Gary
------------------------------
Date: 17 Aug 92 15:49:37 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Energya and Freedom and Soyuz ACRV and...
Newsgroups: sci.space
In article <16l1h1INNa8t@agate.berkeley.edu> gwh@soda.berkeley.edu (George William Herbert) writes:
>In article <1992Aug14.130334.8888@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>>
>>But we will have long duration Shuttles by the time of PMC. So the
>>Shuttle can be crew transport, resupply, material return, and ACRV
>>until we get something better. Not great, but workable with the current
>>fleet. We also get the use of the docked Shuttle's middeck and Canadarm
>>at no extra cost.
>
> Oh great. We're eating up months of shuttle time just sitting them
>at Freedom. With a four orbiter fleet and one permanently on station,
>the number of flights per year will drop around 25% due to less time to
>refurbish (or the same time with a two month delay). We don't need the
>middeck or Canadarm; we've got plenty of lab space (well, not enough, but
>_enough_) and an arm on the station already.
>
> Think these things through...
Indeed. If we follow the plan of using Soyuz and HL Deltas, the Shuttle
fleet is *gone*. That's Sherzer's plan anyway. With this plan 3/4 of the
Shuttle fleet is available for other work than servicing Fred. Now if
your plan includes operating the full Shuttle fleet in *addition*
to Soyuz at the station, then *never mind*. Expensive though.
As to the $65 million firm price for Soyuz, I've posted about this
several times. That may be the price quoted *now*, but wage rates
in the CIS simply can't stay at $12 a month as their economy changes
to a market based system. That's going to have a major impact on
what their space hardware costs. I doubt that *they* have a good idea
what their hardware costs *now* given the baroque accounting methods of
the former Soviet Union, and certainly they can't predict what it
will cost in ten years given the dramatic changes in their economy.
Gary
------------------------------
Date: 17 Aug 92 15:59:55 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Energya and Freedom and Soyuz ACRV and...
Newsgroups: sci.space
In article <1992Aug16.203805.12423@iti.org> aws@iti.org (Allen W. Sherzer) writes:
>In article <1992Aug16.160633.20164@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>
>>No. Launch costs are dominated by support personel costs. Since we
>>only require one Shuttle launch to serve the function that you
>>want to service with four separate launches, we save support costs.
>
>The numbers simply don't bear that out. Shuttle fixed costs are enoumous
>and for the past 11 years have been pretty independant of the number
>of flights. Therefore the reduced suuttle utilization required by
>using Shuttle for ACRV WILL increase costs.
>
>As to my needing more launches, So what? All launches are not equal and
>mine cost a fraction of what yours cost. The bottom line is that shuttle
>based approaches for station crew rotation and resuply costs about $5 billion
>per year and expendable approaches costs about $1 billion per year. The
>expendable approaches also offer greater flexability and fallbacks should
>one component because grounded.
Shuttle fixed cost is around $5 billion a year, but support for Fred
after PMC will only occupy 1/4th the Shuttle fleet at any given time.
That makes the cost of Shuttle support of Fred $1.2 billion per year.
That's close enough to your figures that the increased program risk of
developing *3* new vehicles easily makes the slightly higher cost
acceptable. Using Shuttle keeps 3/4 of the fleet available for missions
*other* than Fred. With your plan, that capability is lost.
Gary
------------------------------
Date: 18 Aug 92 00:36:54 GMT
From: Kenneth Ng <sugra!ken>
Subject: Global Positioning System (GPS)
Newsgroups: sci.space
In article <rabjab.6.0@golem.ucsd.edu:, rabjab@golem.ucsd.edu (Jeff Bytof) writes:
: I am in need of technical reports describing the Global Positioning
: System (GPS). Are they obtainable from NASA or DOD?
Try the Institute of Navigation in Washington DC. Ask for their reprints
on GPS. For the government, contact the Air Force base in Los Angeles. Also
look into Radio Electronics, Hardware Hacker, within the past year.
--
Kenneth Ng
Please reply to kdn5669@hertz.njit.edu for now.
Apple and AT&T lawsuits: Just say NO!
------------------------------
Date: 17 Aug 92 21:41:47 GMT
From: "Edward V. Wright" <ewright@convex.com>
Subject: Private space ventures
Newsgroups: sci.space
In <ZOWIE.92Aug16114108@daedalus.stanford.edu> zowie@daedalus.stanford.edu (Craig "Powderkeg" DeForest) writes:
>Truax is the fellow who built Evil Knievel's steam rocket to jump the Snake River
>canyon.
Not to mention the fellow who studied under Robert Goddard, designed the
US Navy's Polaris missile, and helped design the Atlas ICBM.
>The idea was to have sea launch and recovery to make it cheap, and to adapt
>existing parts rather than build custom ones to build the craft. A few
>years ago, the Air Force bought the prototype from him for a cool 3/4 of a
>million dollars -- enough to buy a house in Palo Alto!
Uhm, not exactly. It wasn't the Air Force, it was the Naval Research
Laboratory, and Truax built the (subscale) prototype under contract
for them.
>Are there any other people around who've come as close to success (defined
>as a private launch) as even Truax did?
Well, Gary Hudson's GCH, Inc. got as far as blowing up a Percheron
rocket on the launch pad (much like NASA in the early 60's) and Pegasus
has gotten as far as placing a few small payloads into orbit.
>[It bugs me that there are people like H Ross Perot, who themselves
>have enough cash to finance their own space programs, but that none, so
>far, has underwritten one.]
What, after his Presidential bid? I can see it now. The launch of
Perot I. T-plus-60 seconds. All systems nominal, in the green, and
go for orbit. Quick, abort, abort, abort! :-)
------------------------------
Date: 18 Aug 92 01:29:00 GMT
From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov
Subject: Private space ventures
Newsgroups: sci.space
In article <ewright.714087707@convex.convex.com>, ewright@convex.com (Edward V. Wright) writes...
>In <ZOWIE.92Aug16114108@daedalus.stanford.edu> zowie@daedalus.stanford.edu (Craig "Powderkeg" DeForest) writes:
>
>>Truax is the fellow who built Evil Knievel's steam rocket to jump the Snake River
>>canyon.
>
>Not to mention the fellow who studied under Robert Goddard, designed the
>US Navy's Polaris missile, and helped design the Atlas ICBM.
And started Project Private enterprise in 1980 which would have been the first
suborbital flight of a manned rocket by a private venture. The astronaut was
a guy by the name of Fell Peters. The plan fell through due to lack of cash
to finace the flight vehicle. Mr. Truax did all of the ground testing.
>
>>The idea was to have sea launch and recovery to make it cheap, and to adapt
>>existing parts rather than build custom ones to build the craft. A few
>>years ago, the Air Force bought the prototype from him for a cool 3/4 of a
>>million dollars -- enough to buy a house in Palo Alto!
Mr. Truax's house was already owned by him in 1980 when I first met him.
Address is 1240 Greenmeadow lane in Palo Alto. He started getting contracts
from the Navy in 1987 if I remember right. The Navy of course is interested
in Mr. Truax's water launched rocket ideas which were proven way back in the
early sixties on the big dumb booster project when he was at aerojet.
>Uhm, not exactly. It wasn't the Air Force, it was the Naval Research
>Laboratory, and Truax built the (subscale) prototype under contract
>for them.
>
The subscale prototype was used for helicopter drop tests to see how much
damage would occur in a typical splash down. The last I heard (about two years
ago) the first tests were unsuccessful due to excessive damage to the rocket.
The idea was complete reusablity with the recovery of the Allen's precious
RL-10's. Did not work so well.
>>Are there any other people around who've come as close to success (defined
>>as a private launch) as even Truax did?
Deke Slayton's Space Services Incorporated for one. He has been launching
sounding rockets for 12 years and will launch his first orbital vehicle with
the launch of COMET I next march.
Payload Systems Inc from up in the northeast run by Brian Lichetenburg is
another company that is making it.
Battelle Labs who flies many payloads with our Consortium is another one.
McDonnell Douglas here in Huntsville does microgravity payloads all the time.
Essex corp does mockups for most of the major Nasa programs is another success.
New Technology Incorporated here in Huntsville provides personnel to support the
Marshall spacelab missions is another private company.
Orbital Sciences is also a success at least for the time being.
Defense Systems is a maker of small satellites for both the military and
other buyers in the commercial market.
Starsys provides radiolocation services to a wide entirely commercial market
as well as emergency beacon location services for local, state and federal
customers.
I can go on and on.
>Well, Gary Hudson's GCH, Inc. got as far as blowing up a Percheron
>rocket on the launch pad (much like NASA in the early 60's) and Pegasus
>has gotten as far as placing a few small payloads into orbit.
>
>
>>[It bugs me that there are people like H Ross Perot, who themselves
>>have enough cash to finance their own space programs, but that none, so
>>far, has underwritten one.]
Ross is a computer geek. No one has approached him yet with a good enough
idea that I know of.
By the way message to Allen. Your infrastructre costs are about 2 billion over
what you project for a similar project in your HL Delta and Atlas. Also have
you read abouty all of the troubles with the mere upgrade of the Titan IV
SRB's? That has cost 200 megabucks already. What about the Titan pad upgrads
at LC 40. That alone was 400 million. Where do you get your low numbers for
all of your pads and clean rooms and etc..... Also your number for the
S V engines are 20 percent over what Rockwell has stated the cost would be.
(400 million vs your number of 500 million) How many other times have your
numbers had this over statement for other projects?
I like HL Delta and and Atlas. HL Titan is way overpriced however, with Titan
IV launches already in the Shuttle ballpark per mission. I hope the other
"new and improved" ideas of yours are not similiarly fated to cost jump. Oh
by the way, it is unfortunate but true that Pegasus launches have went from
a six million dollar quote to ten million dollar quote. I love Pegasus and
wish it the best but hey that is a 40% increase between vaporware and hardware.
Funny how that happens in this business.
Dennis, University of Alabama in Huntsville
------------------------------
Date: 18 Aug 92 02:11:43 GMT
From: Chris Petersen <bungee@Apple.COM>
Subject: REQUEST: Mars face gif
Newsgroups: sci.space
I actually have a need for the GIF of the "face" on the surface of Mars. I
grabbed it when it appeared in sci.space before...but I seemed to have
misplaced it.
Could someone please post it, or email it, or simply give me an address where
I can find it.
Thanks,
-chris
bungee@apple.com
------------------------------
Date: 17 Aug 92 21:32:50 GMT
From: David Cornutt <cornutt@lambda.msfc.nasa.gov>
Subject: Seeking SSF payload user requirements
Newsgroups: sci.space
I am seeking requirements and inputs from SSF payload users whose
payloads are sponsored by one of the three NASA payload offices (Office
of Space Science and Applications (OSSA), Office of Aeronautics and
Space Technology (OAST), and Office of Commercial Programs (OCP)). My
group, working for the Marshall Space Flight Center Mission Operations
Lab, is gathering information about user requirements for the U.S.
Operations Center (USOC). We would like to get information about
people's operations concepts: how would you like to control your
payload, where and how do you want to run things, and what kind of
interfaces and services (telemetry, command, voice, video, ancillary
data, etc.) do you need to do science? Some general background info on
your payload would be nice too. (I'm not asking anyone to reveal
private or proprietary information.) Also, if you have flown previously
on Shuttle or Spacelab, a summary of your experiences, and suggestions
for how SSF could improve on these things, would be appreciated. I can
be of help in providing information about ground systems concepts, and
dispelling rumors.
If you are seriously persuing flying a payload on SSF anytime during
the man-tended phase (or even later), I would like to hear from you.
Please contact my by:
1. reply to this message
2. E-mail: Internet: cornutt@lambda.msfc.nasa.gov
SPAN: 8849::CORNUTT
NASAmail: DCORNUTT
GSFC Telemail: (UN:DCORNUTT, SITE:NASA)
3. Phone: (205) 461-4517 (commercial and FTS)
Note that I am interested in hearing from potential payload users only;
flames about SSF from casual onlookers will be cheerfully ignored.
Also, I work ground systems. I have no direct influence over the
onboard system. (If you want to send me comments about the onboard
system, I will pass them on, but I make no promises in that area.)
--
David Cornutt, New Technology Inc., Huntsville, AL (205) 461-6457
(cornutt@freedom.msfc.nasa.gov; some insane route applies)
"The opinions expressed herein are not necessarily those of my employer,
not necessarily mine, and probably not necessary."
------------------------------
Date: 18 Aug 92 02:28:29 GMT
From: "Frederick A. Ringwald" <Frederick.A.Ringwald@dartmouth.edu>
Subject: SPS feasibility and other space development
Newsgroups: sci.space
Listen, Dennis, a scientist's job is ask questions: and the harder they
are, and the more skeptical they are, the better they are. That's how
you get important results!
I am doing my job. What are you doing?
Uncritical acceptance of ideas, no matter how appealing they might
seem, is very bad for any field, and space flight is no exception.
People will hold you to promises you make, and will hold it against you
if you tell them things that aren't right. Undisciplined grand
speculation isn't even good science fiction. Even at best, boosterism
(good pun intended) can be misleading; and at worst, it makes you look
kooky. Believe me, kooky is NOT an image you want to project when
writing a research proposal, especially not when you get to the budget
section!
If you can't provide me with even approximate literature references
better than newspaper articles, especially when I repeatedly request
them, I wonder how much you really know about this stuff. I suppose
I'll have to go back to doing my own homework, and so much for the net
as a research tool. Never mind numbers accurate to the nth digit; I'd
welcome numbers *reliable* to the first digit. Also, I always get very
suspicious about anything I'm not allowed to ask questions about!
What is it about this field that so often elicits a quasi-religious
response? My fondest dream that still hasn't come true is to find a way
to fly to the stars and be back by Monday morning. But there are some
good reasons to believe this might not be so easy. Until I figure out
some even better reasons to believe it might be feasible after all,
I'll keep busy with practical, mundane, unimaginative things like
outbursts around neutron stars, bending waves in accretion disks, and
dwarf nova outbursts going off before my very eyes (or instruments).
I've certainly had enough of *this*!
P.S. Your new postings about reviving the Saturn are *much* more like
it. Not only is this of potential long-term interest, but there's
nothing like the immediate applicability of the rumble of a rocket
engine. With all the excitement lately, I'm almost scared to ask
another question, but ask I will: what are the F1A engines for? Why
revive the Saturn class? It makes no sense to have capability for no
reason; the taxpayers won't like it. So, what are the reasons? Most
interestingly, what are the payloads? SSF parts? Large comsats? Lunar
or planetary spacecraft?
------------------------------
Date: 18 Aug 92 01:18:53 GMT
From: "Frederick A. Ringwald" <Frederick.A.Ringwald@dartmouth.edu>
Subject: SPS fouling astronomy (long)
Newsgroups: sci.space
In article <roelle.714081429@uars_mag>
roelle@uars_mag.jhuapl.edu (Curtis Roelle) writes:
> Are there really persons out there who believe a fair assessment of
> the physical universe can be made by restricting our view to the
> celestial cones around Earth's polar regions?
I'm fond of the Milky Way myself, but I'm not *too* worried about its
imminent demise at the hands of SPS. Much of this thread shows that SPS
is a very advanced concept, and maybe necessarily so (although no one
so far has picked up on the idea of making them out of gossamer, the
whole satellite resembling a gigantic net of fine wire; this idea is
only partly stolen from Freeman Dyson). I think we've seen clearly that
many problems need to be solved if SPS is going to become economically
feasible. In the meantime, competing technologies may not be standing
still. A breakthrough in superconducting cable (either solve the flux
creep problem in the new kind, or perfect an inexpensive manufacturing
process for the old kind), or improvements in hydrogen combustion
technology, are only two examples what might solve the energy storage
problems that ground-based solar and wind power now have. So might a
breakthrough in nuclear fusion technology, although if you like hard
problems to solve, this is the field for you. You can start with the
basic plasma physics, one problem being the equations are linearized,
although high-order effects often dominate the observed behavior of
real plasmas. Another problem is that we really don't have enough
observations of the behavior of real plasmas, and there is little
funding to do it; I know several young experimental plasma people who
used to be interested in fusion, but have now defected to space
physics. Then there's the first-wall problem, and of course the heating
and confinement problems. Maybe if they started all over from scratch,
with magnetic bottles...
Of course, breakthroughs being breakthroughs, they're unpredictable,
and so by definition you can't count on them for anything in advance.
But, SPS itself will require it own breakthroughs in space launch and
operations technologies. For example, anything the Space Shuttle now
carries has to be worth about its weight in gold, to be profitable
(that's $4e8/65000 lbs, or about $400/oz). This isn't so bad, though,
since some things, such as communications satellites, are worth more
than this (and the photons streaming through their channels are
massless). It will be interesting to see if space manufactured
materials, such as pharmaceuticals, can beat the transportation costs,
although they too will have competition from the ground; adapting the
technology from film recovery from photo reconnaissance satellites
might help in bringing things down. DCX may also help, but space flight
will still be much more expensive than jet travel, and while jets are
fine for passengers and FedEx packages, they're still very expensive
for bulk freight. So, there's an incentive to develop extraterrestrial
resources, such as lunar concrete for construction. But current
estimates (all sketchy) for a Moon base are in the range of $100-500
billion. This is more expensive than even the Apollo project, which was
carried out in the best of economic times and even then widely
criticized as too expensive. But of course, the Apollo project did not
have making a profit among its primary goals. So, there's an incentive
to automate as much as possible, and to develop less expensive
technologies for getting lunar material into space, such as
electromagnetic mass drivers and powdered aluminum/oxygen rockets.
Industrial processing will need to be worked out in the space
environment, where air, water, and human supervision come at a premium.
There may be advantages in readily available solar energy, hard vacuum,
and microgravity, although there may be liabilities, too, such as
radiating waste heat away from a large structure. (Sound familiar?)
SPS is also not without its own unique problems. Microwave power
transmission presents safety problems, and terawatts of transmitted
power may well generate enough static to interfere with
telecommunications, not to mention cause the demise of ground-based
(i.e., inexpensive) radio astronomy. Laser transmission, at various
wavelengths, has problems with clouds and atmospheric water vapor,
which you might be able to get around by putting the receivers on large
balloons, but these present problems, too. (There aren't too many large
balloons, these days. But there used to be. Many of them crashed.)
I don't know about you, but this is beginning to sound like epicycles
upon epicycles to me. When I was little, I heard a lot about the "world
of the future": but if there's anything I've learned about the future,
it's that it always comes out a LOT different from how you think it'll
come out. We don't have jet packs or flying cars, which even if they
were practical, would probably be noisy and dangerous. But we do have
personal computers, which are perhaps much more wonderful, especially
for a kid who really hated adding up long columns of numbers (and
really hated typing, too). The Cold War is over, too, something I
certainly never expected to live to see.
So don't worry about the demise of the Milky Way. It's already taking a
beating in every city in the world! And if it becomes profitable to
construct SPS, it'll happen; if not, then not. This whole argument has
taken on the air of a SETI debate: every contingency entails multiple
uncertainties and lots of assumptions. This concept is just plain too
advanced: the only way to get away from lots of the uncertainties is to
try to run experiments (e.g., for SETI, do radio searches, or
orgin-of-life laboratory experiments, or searches for extrasolar
planets). I think I've had enough, for now!
P.S. At the South Pole, there is some interesting astronomical work
going on. When the weather is clear, a solar telescope takes
measurements of the Sun used to probe its interior by analyzing
pressure waves in its surface, in a manner not unlike seismology;
helioseismology, it's called. The South Pole has an important
geographic advantage: the last I heard, the longest uninterrupted run
they had was eight days long. This makes for tasty frequency
resolution, the best so far. Then there's the cosmic ray project, to
analyze waves in the interplanetary medium. (They wanted to hire me to
take care of it, but I turned them down. Living at the South Pole would
be fun, for three weeks, but they wanted me to stay for 53 weeks!
Anytime anyone razzes me about this decision, I say "Well, there's a
job open: why don't YOU do it?") There's also a high energy gamma ray
instrument, and interest in infrared instruments, to take advantage of
the high altitude and dry air, at least one being a cosmic background
experiment, to follow up on the COBE results. There's even talk of a
2.5-m class optical telescope, mainly for time series work such as
asteroseismology, although it'll have to deal with the aurora and with
the normally just-awful weather.
------------------------------
Date: 18 Aug 92 00:39:28 GMT
From: Kenneth Ng <sugra!ken>
Subject: Star Trek (anti-)realism
Newsgroups: sci.space
In article <713917714snx@pands.demon.co.uk:, paul@pands.demon.co.uk (Paul Wilson) writes:
: > My favorite in science fiction space travel like Star Trek and Star Wars is
: > the asteroid field. Never mind that even crowded fields they are still (in
: > reality) mostly space.
: True, but reality can make for some pretty lousy TV!
True, and conversely, I must commend Star Trek for being *IN* *GENERAL* the
most accurate of the various popular Science Fiction television shows.
--
Kenneth Ng
Please reply to kdn5669@hertz.njit.edu for now.
Apple and AT&T lawsuits: Just say NO!
------------------------------
Date: P
From: P
Received: from VACATION.VENARI.CS.CMU.EDU by isu.isunet.edu (5.64/A/UX-2.01)
id AA20039; Mon, 17 Aug 92 18:04:24 EDT
Received: from crabapple.srv.cs.cmu.edu by VACATION.VENARI.CS.CMU.EDU
id ab02674; 17 Aug 92 17:56:14 EDT
To: bb-sci-space@CRABAPPLE.SRV.CS.CMU.EDU
Path: crabapple.srv.cs.cmu.edu!cantaloupe.srv.cs.cmu.edu!das-news.harvard.edu!ogicse!uwm.edu!cs.utexas.edu!convex!convex!ewright
From: "Edward V. Wright" <ewright@convex.com>
Newsgroups: sci.space
Subject: Re: Whales and Dolphins
Message-Id: <ewright.714085091@convex.convex.com>
Date: 17 Aug 92 20:58:11 GMT
Article-I.D.: convex.ewright.714085091
References: <9208081935.AA29109@cmr.ncsl.nist.gov>
Sender: news access account <usenet@neptune.convex.com>
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
Lines: 46
Nntp-Posting-Host: bach.convex.com
X-Disclaimer: This message was written by a user at CONVEX Computer
Corp. The opinions expressed are those of the user and
not necessarily those of CONVEX.
Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU
Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU
In <9208081935.AA29109@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes:
>Reread what I posted. Humans take calculated risks, and sometimes there
>are mistakes in the calculations.
Reread what I posted. There are many people whose job is to save other
people's lives *regardless* of the risk to their own.
Suppose, for example, the President of United States, or one of his
family, was kidnapped by a foreign power. Do you believe that the
United States government would not try to rescue him if it believed
more than one soldier would die in the attempt?
>Whales that beach themselves entirely seldom if ever survive (though on
>the "R-rated Gory Animal Videos" series commercials on television, they
>show a killer whale getting its head out on the beach to chomp a sea lion).
Nope. Not true. Not even close. Killer whales have been known to
deliberately wash schools of fish up onto the beach, then beach themselves
to snatch up the helpless, flopping fish, and roll back into the water.
They have been observed and photographed doing this. You aren't proving
that whales aren't intelligent. You're simply showing how little you
know about whales.
>If whales have anything akin to human intelligence, and if they have a
>community that communicates and passes down lore, then they must realize
>that if they beach themselves, they're going to die,
If humans have anything akin to intelligence, and if they have a
community that communicates and passes down lore, then they must
realize that if they beach themselves, they're going to be exposed
to dangerous levels of UV radiation, contract skin cancer and die.
Ergo, humans cannot be intelligent.
>If what the whales do is deliberate suicide, it's even less akin to normal
>human behavior.
Of course. One human being may voluntarily expose himself to
dangerous levels of UV radiation at the beach, but certainly
his entire family wouldn't follow, would they? If one human
is out drinking with his buddies, gets drunk and jumps into
his car, his friends aren't going to pile in with him, are they?
Nah, that could never happen, could it?
------------------------------
End of Space Digest Volume 15 : Issue 122
------------------------------