Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v15_0/v15no084.txt

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Date: Sat,  8 Aug 92 05:00:03
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #084
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat,  8 Aug 92       Volume 15 : Issue 084

Today's Topics:
     [news.announce.newgroups] 2nd CFV: talk.politics new groups
                           Comm. Space Act?
                 Heavy Boots (and Uniforms) (2 msgs)
                      Home made rockets (2 msgs)
                Mir Cosmonauts in Woodstock, Illinois
                        Origin of Life article
                      Source of moon/apollo pix
                      Soyuz-Progress data (long)
                        Soyuz as ACRV (2 msgs)
                   SPS and light pollution (2 msgs)
                        SPS fouling astronomy
                          What is the ASRM??

    Welcome to the Space Digest!!  Please send your messages to
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Date: Thu, 6 Aug 1992 09:17:54 GMT
From: Jyrki Kuoppala <[e-mail]>
Subject: [news.announce.newgroups] 2nd CFV: talk.politics new groups
Newsgroups: alt.sex.motss,alt.sex.bondage,soc.motss,alt.politics.homosexuality,soc.rights.human,alt.individualism,sci.space,sci.physics,talk.politics.space,sci.misc

In article <[e-mail]>, jkp@cs (Jyrki Kuoppala) writes:
>CALL FOR VOTES: talk.politics new groups

[ rest deleted ]

For your information, the list of newsgroups on the vote follows.  See
article <[e-mail]> in
news.announce.newgroups to which this article is a followup to for
detailed information on the vote.

talk.politics.usa.misc        Misc. USA politics.
talk.politics.usa.constitution    U.S. Constitutional politics
talk.politics.canada        Politics of and in Canada
talk.politics.asia.japan    Politics of and in Japan
talk.politics.asia.taiwan    Politics of and in Taiwan
talk.politics.europe.britain    Politics of and in Great Britain
talk.politics.org.ec        European Community politics
talk.politics.org.un        Politics of United Nations
talk.politics.org.spook        "Spook" organizations around the world
talk.politics.org.misc        Political organizations
talk.politics.europe.misc    Misc. discussion on European politics
talk.politics.europe.nordic    Politics of Norden
talk.politics.europe.baltic    Politics of Baltic countries
talk.politics.europe.east    East European politics
talk.politics.europe.balkan    Balkanese politics
talk.politics.latin-america    Latin American politics
talk.politics.north-america    Politics of Northern America
talk.politics.americas        Geopolitics on the American continents
talk.politics.africa.misc    Politics in Africa
talk.politics.asia.misc        Politics in Asia
talk.politics.asia.southwest    Politics in South-West Asia
talk.politics.asia.southeast    Politics in South-East Asia
talk.politics.asia.south    Politics in South Asia
talk.politics.australasia    Politics in Australasia
talk.politics.antarctica    Politics of the Antarctic
talk.politics.elections        Elections discussions and reports
talk.politics.sex        "Blue laws", decency laws, sexual behaviour
talk.politics.equality        Equality and discrimination
talk.politics.civil-liberty     Civil liberties
talk.politics.libertarian    The libertarian ideology
talk.politics.constitution    A constitution as a basis for a society
talk.politics.economics        Political economics: taxes, gov. budgets
talk.politics.media        Media and politics
talk.politics.usenet        Politics of Usenet
talk.politics.science        Politics in science.
talk.politics.health        Health care, politics in medicine, etc.
talk.politics.ethics        Ethics in politics.
talk.politics.work        Workplace and employment politics
talk.politics.reform        Political reform

//Jyrki

------------------------------

Date: Fri, 7 Aug 1992 13:19:35 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Comm. Space Act?
Newsgroups: sci.space

In article <geU5Lse00WB60BCoF=@andrew.cmu.edu> David O Hunt <[e-mail]> writes:
>What _is_ the commercial space act?  Could someone please post some
>information?

Below is a summary of this bill I posted to talk when it was introduced:


                  One Small Step for a Space Activist...
                                      by
                            Allen Sherzer & Tim Kyger

On November 21, 1991 the Democrat version of the Omnibus Commercial Space
Act was introduced in Congress. HR 3848, the "Commercial Space Competitiveness
Act" is primarily a subset of the Walker bill. The "Hall/Walker" (HR 3848);
(confused yet?) does the following:

Section 201 - Extends government payment of excess third party claims from the
five year period specified in the 1988 Commercial Space Launch Act Amendments
to January 1, 2000.

Section 202 - Extends the Launch Services Purchase Act to cover suborbital
flights. This section also requires NASA to submit to Congress a plan to make
better use of commercial suborbital rockets.

Section 203 - Launch vouchers. NASA will be authorized to issue vouchers good
for the purchase of commercial launch and payload integration services. This
provision will encourage scientists to standardize payload interfaces and buy
turnkey launch services.

Section 204 - Infrastructure matching grants. The DoT will form a selection
committee with one representative from DoT, DoD, and NASA. This committee can
make matching grants for projects to build space infrastructure.

Section 205 - Commercial Space Transportation Trust Fnd. All fees collected
by DoT for licensing of commercial launch activities will be placed in a trust
fund which will be used for projects which will benefit the US space
transportation industry.

Section 206 - Identification of excess facilities.  NASA, DoT, and DoT will
produce an inventory of all US launch facilities and identify those which
are not needed. Unlike the Walker bill, HR 3848 does not require that the
extra facilities be sold.

Section 301 - Use of missile assets by federal agencies. This is where it
can get nasty. Section 301 grants the government permission to use existing
missile inventory for launches. Although it has provisions requiring that all
costs be accounted for and that the effects it has on commercial providers be
considered this is still a dangerous section. Large numbers of surplus ICBM's
being dumped on the market could well bankrupt commercial providers.

Section 401 - Anchor tenancy and termination liability. This section
authorizes the government to engage in anchor tennancy agreements with
providers of commercial services. In addition, the National Aeronautics and
Space Act is amended to allow the government to provide better termination
liability. Arrangements like this have worked well in other industries and
should be a big help here as well.

Section 402 - Use of government facilities. This section authorizes non-federal
entities to use space related facilities on a reimbursement basis.

Section 403 - Protection of information developed under space act agreements.
This section will allow the government to protect research results and valuable
discoveries. This will help to provide more incentive to companies because
they will retain patent rights to discoveries jointly made with NASA.

Section 404 - Commercial space achievement award. The Secretary of Commerce
and the Chair of the National Space Council will award Commercial Space
Achievement Awards to individuals, corporations, and corporate divisions for
getting more than half their revenue from space activity funded by sources
outside the federal government, or for other significant space advances.


--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------259 DAYS TO FIRST FLIGHT OF DCX----------------------+

------------------------------

Date: 6 Aug 92 18:53:05 GMT
From: Bruce Watson <[e-mail]>
Subject: Heavy Boots (and Uniforms)
Newsgroups: sci.astro,sci.space,sci.misc

In a recent article in our local sunday newspaper magazine supplement
investigating the availability to consumers at some future date of
the technology featured in the TV program "Star Trek: The Next
Generation", faster-than-light travel was considered.

A pphysicist at Lawrence Livermore was interviewed for the topic.
He said, "traveling faster than light is "in the unforeseeable future".
That may require new physics that we don't have today." So far, so good.

But then the reporter takes over:

"Textbooks state that nothing can travel faster than the speed of light,
which is 186,282 miles a second. And there are daunting problems just
getting close to light speed -- matter tends to get much heavier,
for instance, raising the possibility that travelers would be crushed
by their own bulk."
--
 __________________________________________________________________________
|[e-mail]|    "Another Case of too many scientists and     |
|Bruce Watson            |     not enough hunchbacks." -- Gary Larson      |

------------------------------

Date: 7 Aug 92 16:43:37 GMT
From: Don Roberts <[e-mail]>
Subject: Heavy Boots (and Uniforms)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Bruce Watson) writes:
>
>In a recent article in our local sunday newspaper magazine supplement
>investigating the availability to consumers at some future date of
>the technology featured in the TV program "Star Trek: The Next
>Generation", faster-than-light travel was considered.
>
>A physicist at Lawrence Livermore was interviewed for the topic.
>He said, "traveling faster than light is "in the unforeseeable future".
>That may require new physics that we don't have today." So far, so good.
>
>But then the reporter takes over:
>
>"Textbooks state that nothing can travel faster than the speed of light,
>which is 186,282 miles a second. And there are daunting problems just
>getting close to light speed -- matter tends to get much heavier,
>for instance, raising the possibility that travelers would be crushed
>by their own bulk."
>--
> __________________________________________________________________________
>|[e-mail]|    "Another Case of too many scientists and     |
>|Bruce Watson            |     not enough hunchbacks." -- Gary Larson      |


The physicist interviewed in the article (which first appeared in the San
Jose Mercury News) is two doors down from me here at the Lab. I pointed out
this passage to him when the article appeared, and he was pretty embarrassed.
The reporter, it seems, saw fit to embellish the information he'd obtained
without checking with anyone on his accuracy.

This demonstrates that we must be *very careful* of what we say when trying
to explain physics in a non-technical context. To someone well versed in
special relativity, pointing out that near c, masses approach infinity seems
a convincing argument against faster-than-light travel by conventional means.
But tell a reporter that as you approach the speed of light, things become
infinitely heavy, and what conclusions do you expect he'll draw?

    -- Don
--
 Dr. Donald W. Roberts
   University of California                              Physicist
   Lawrence Livermore National Laboratory             Weightlifter
   [e-mail]

------------------------------

Date: 7 Aug 92 12:45:35 GMT
From: John Roberts <[e-mail]>
Subject: Home made rockets
Newsgroups: sci.space

-From: [e-mail]
-Subject: Home made rockets
-Date: 5 Aug 92 19:36:06 GMT
-Organization: University of Cape Town

-I have recently got into the field of making home-made rockets and have been
-experimenting with various types of cheap, readily availible fuels and
-cannisters. We have found that the best rockets to date are made of salt peter
-and castor sugar, mixed in a half, half ratio. This is then heated to melting
-point and spooned into container.

-The best launch went to about 250m for 100gms of ingredients. Launch sites have
-proved to be a bit of a problem as with the current state of political affairs
-here, we are a touch scared of being arrested.

-If anyone has any new/different ideas for fuels, chemical components, homemade
-flares, please let me know.

Now that commercial model rocket engines are readily available, building
your own rocket engines is strongly discouraged, except perhaps for hotshot
mechanical engineers who have had extensive training in the field.

In the old days when people made their own rocket engines, KNO3 and sugar was
discouraged, because of safety problems:
 - The flash point of the mix is not a whole lot greater than the melting
   point. This would be adequately controllable with industrial processing
   equipment, but just heating it in a pan over a stove, there's too much
   risk of getting a local hot spot.
 - Molten sugar is extremely sticky, and tends to coat everything it touches.
   When pouring the mix into the engine, there's a significant risk of getting
   some of it in the wrong place.
 - Sugar is prone to absorbing moisture from the atmosphere, changing the
   properties of the fuel (perhaps even causing it to drip out of the engine).
 - There's a pretty good chance of getting covered with flaming syrup while
   processing the mix. You can probably write off any skin surface this
   happens to.

Again, back in the old days, the recommended mix was powdered zinc and sulfur.
I can find you a reference to an old Air Force book on model rockets, if you
like. Don't forget the sandbags around the fuel press, the square miles of
safety range, the sunken launch pad, the safety observers, the concrete
bunker,.... :-)

I can't do anything about the local laws. Maybe you can get yourself declared
an experimental rocket institute. :-)

You may get the impression from all this that building rocket engines is
an extremely difficult and potentially dangerous undertaking, that should
only be attempted with extreme care, concentration, and observance of the
local laws. That is a correct impression.

John Roberts
[e-mail]

------------------------------

Date: Fri, 7 Aug 1992 17:09:44 GMT
From: Henry Spencer <[e-mail]>
Subject: Home made rockets
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Frederick A. Ringwald) writes:
>> I have recently got into the field of making home-made rockets ...
>
>What you describe doing is amazingly dangerous. If you persist in it, I
>hope you do get caught and arrested, as you are a public menace, if
>you're still alive to read this post!

What I posted the last time this came up:

From henry Sat Jan 14 23:49:34 EST 1989
Article: 9131 of sci.space:
Newsgroups: sci.space
Path: utzoo!henry
From: [e-mail] (Henry Spencer)
Subject: Re: Re: Making model rocket engines.  ---> Don't!
Message-ID: <[e-mail]>
Organization: U of Toronto Zoology
References: <[e-mail]> <[e-mail]>
Date: Sun, 15 Jan 89 04:48:47 GMT

In article <[e-mail]> [e-mail] (Bob Pendleton) writes:
>If you're not a pro, DON'T try it. It just isn't as simple as it
>looks.

I'd revise that slightly:  if you're not a pro, don't try it unless you
are prepared to turn yourself into at least a semi-pro first.  Study the
field rather than trying to just blunder ahead on your own; pros know
that it's not an easy job, and are grateful for all the help they can get.
Take precautions against damage to equipment (minor), yourself (serious),
or innocent bystanders (awful damn serious, especially in a country like
the US that has let its liability lawyers go berserk); pros know that
explosions and other violent failures are a normal part of rocket-engine
development, and that a small quantity of explosives (e.g. rocket fuel)
will produce a much bigger explosion than most laymen think.  Plan for
thorough testing under varied conditions before trying to use the engine
"for real"; pros know that having it work once or twice doesn't mean it
will always work under those conditions, never mind others.

Once all rocket engineers were amateurs, but the sensible ones turned
themselves into pros as quickly as they could.  Oddly enough, they were
the ones who ended up building reliable, useful engines.
--
"God willing, we will return." |     Henry Spencer at U of Toronto Zoology
-Eugene Cernan, the Moon, 1972 | uunet!attcan!utzoo!henry [e-mail]


--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

------------------------------

Date: 7 Aug 92 18:32:49 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Mir Cosmonauts in Woodstock, Illinois
Newsgroups: sci.space,chi.general

           MIR COSMONAUTS TO SPEAK IN WOODSTOCK, ILLINOIS

Cosmonauts Sergi Krikaliov and Anatoli Artsebarski will speak
next week at the Woodstock Opera House, 121 Van Buren St., Woodstock,
Illinois. Box office number is [phone].  Admission is $5.00 per
person; tickets will be available at the door.

Presentations will be:

Monday, 10 August 7:30 PM
Tuesday, 11 August 10:00 AM

They were on the crew of Soyuz TM-12 in May 1991, which brought
British cosmonaut Helen Sharman to the Mir space station.  Artsebarski
was commander of Mir during 5/91 to 11/91.   He returned home, but due
to budget constraints  Krikaliov remained aboard Mir until 25 March
1992 for a 312-day stay.  (He has entered into folklore-- yes, there
is even a song about this-- as "the guy who was stranded," although,
of course, a Soyuz capsule was docked to the station at all times and
the crew could have departed quickly if any emergency occurred.)

The cosmonauts will be bringing never-before-seen personal video &
photographs taken aboard the station, including shots of the Gulf War
aftermath from space, extensive spacewalk construction activities,
and, of course, the ever-popular "playing with our food in
weightlessness."  There will be a reception after the talk.

                     ===========================
I attended a dinner last night where Artsebarksi and Krikaliov spoke.
I'm afraid I don't have time to write it up in detail now, but thought
you'd like to know that they're talking in Woodstock.  (It's a little
town about an hour northwest of O'Hare, pretty far from Chicago. The
Opera House is right in the town square, so you can find it if you can
find Woodstock at all.  Nice little theater.)

Other ex-Soviets I met included  Dr. Gulsra ("Julia") Ospanova,
Assistant Minister of Health for Dentistry in the Russian Federation,
and formerly  personal dentist to the cosmonauts & other high
officials.  She was on the barricades defending the Russian White
House  during the attempted coup last summer.  I also met an engineer
from Energiya NPO, the "company" responsible for space stations and
the Energiya rocket, named Alexander Jereniotsky. He designed the
memory-metal devices the cosmonauts added to Mir last summer.
It's possible that these people or their families may be appearing in
Woodstock with the cosmonauts, but I'm not really sure and the box
office doesn't know.

Krikaliov and Artsebarski will be attending the meeting of the
Association of Space Explorers in Washington, D.C., just before the
World Space Congress at the end of this month, so I may get to see
them again.

     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     [e-mail]
   -   -       Internet:  [e-mail]
     ~         SPAN/Hepnet:      43011::HIGGINS

------------------------------

Date: Fri,  7 Aug 1992 12:45:37 -0400
From: David O Hunt <[e-mail]>
Subject: Origin of Life article
Newsgroups: talk.origins,sci.skeptic,sci.space

>>As to the few problems that arise in the evolutionary support...suppose
>>I give you a coin.  You flip it 1,000,000 times, and 999,999 times it comes
>>up heads, once tails.  Are you _seriously_ going to tell me that the odds
>>of the next one being tails are favorable?  Definite?  Because that's what
>>you're claiming with the _overwhelming_ evidence for evolution.
>
>   Just to nit pick, but given a fair coin, the previous 1,000,000
>   tosses have absolutely no bearing on the next.  The odds of the
>   next toss being tails are still 50-50.  I understand your point,
>   but your analogy is flawed.

You forget the possibility that we're dealing with a loaded coin!  :)

David
[e-mail]

------------------------------

Date: Fri, 7 Aug 1992 06:08:03 GMT
From: Mike Smithwick <[e-mail]>
Subject: Source of moon/apollo pix
Newsgroups: sci.space

[]

I've recently uncovered a great set of slides I picked up about 10 years ago. It
is 80 (yup, 80) color slides of the Apollo 15 mission for about 15 bucks.
These were published by a company called "Holiday Films". Anyone know
if these people are still around? If not, anyone know of a good source
of Apollo or Moon (lunar orbiter, etc.) slides (or gifs).


Mike

--
"There is no problem too big that can't be solved with high explosives"-Rush

Mike Smithwick - ames!zorch!mike

------------------------------

Date: 7 Aug 92 15:20:18 GMT
From: "R. Cage" <[e-mail]>
Subject: Soyuz-Progress data (long)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dennis Newkirk) writes:
>The capsule was designed to perform ballistic reentry from lunar
>distances which resulted in from 10 to 16 gravities.

If reentry from LEO results in accelerations anywhere near
as high, it appears that Soyuz is unsuitable for safe return
of an ill person from orbit.  A lifting capsule is required.
--
    "And I don't think cripples, gays or Jews make particularly good
citizens.  Killing them is a positive moral good to the human race and
to the planet." -- Steve Arnold, <[e-mail]>,
his entire text, later disclaimed; sarcasm, or Freudian slip?  You decide.

------------------------------

Date: Fri, 7 Aug 1992 17:01:19 GMT
From: Henry Spencer <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>>Unless COMET has changed radically since the early proposals, only a
>>fraction of the mass that comes down in its capsule actually counts as
>>payload.  But most of the extra is things that aren't needed for a
>>dedicated payload-return capsule.
>
>Henry the extras on the COMET are for the return capsule. The data system and
>almost everthing else is in the orbiting portion that will not return...

Okay, that *is* seriously different from the proposal I saw, which emphasized
maximum re-use and hence had everything come back down.

None of which invalidates the basic point:  that substantial reentry capsules
are a proven technology, presenting no major difficulty or great development
cost for individual loads up to a ton or so.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

------------------------------

Date: Fri, 7 Aug 1992 17:07:50 GMT
From: Henry Spencer <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (University Space Society) writes:
>... ignoring physics. The exaust velocity of the fuel is in the
>thousands of meters per second which means that neither one will be a
>pollution producer.

Sorry, Dennis, that exhaust velocity is an *average*.  There is always
some small fraction which emerges at much lower velocity.  Hence the
well-known problems with plume contamination of things that are far away
from the exhaust nozzles.  I've seen designs for new-technology capsules
with two maneuvering systems, a conventional one for most purposes and
a xenon-gas system for maneuvering near pollution-sensitive satellites.

>the large payloads that need returning will have to use Shuttle...

What large payloads?

>any delicate experimental result must also use shuttle due to the much milder
>G environment than is possible with any type of ballistic trajectory be it
>a tether or retropropulsion.

Remember that a lifting capsule flies a rather gentler trajectory than a
straight ballistic one.  Not as gentle as wings, admittedly.  On the other
hand, not all experimental results are as delicate as they first seem.
PSI got their protein-crystallization results down fine on a Soyuz.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

------------------------------

Date: 7 Aug 92 17:14:23 GMT
From: "R. Cage" <[e-mail]>
Subject: SPS and light pollution
Newsgroups: sci.space,sci.energy

In article <[e-mail]> [e-mail] (Frederick A. Ringwald) writes:
>(My biggest problem with SPS still is: do you really think you can make
>a living at it? Seems to me that ground-based Solar would be amazingly
>cheaper and less trouble. Wind is making surprisingly good progress,
>too. And these contraptions are made of native materials, too: from
>Earth.)

Ground-based solar is available only during daylight, and has
seriously reduced availability in the winter months at higher
latitudes.  This requires long-distance transport or long-term
energy storage, which would be real nice to have anyway; we
don't.  SPS is there almost all the time, and its out-periods
are quite predictable (and at low-demand hours, too).  Wind
is also quite irregular.

The entire rationale behind SPS is the provision of base-load
power from renewables.  Peaking power in SoCal could be from
ground-based solar, but that won't charge the batteries in
the electric cars at 2 AM, to give just one example.  Wind is
so irregular that its only value is to offset some fossil
consumption.
--
Russ Cage   [e-mail]  [e-mail]
  *  When Ford pays me for my opinions, THEN they can call them theirs. *

                           _Bad_ cop.  No donut.

------------------------------

Date: Fri, 7 Aug 1992 17:18:55 GMT
From: Henry Spencer <[e-mail]>
Subject: SPS and light pollution
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Frederick A. Ringwald) writes:
>(My biggest problem with SPS still is: do you really think you can make
>a living at it? Seems to me that ground-based Solar would be amazingly
>cheaper and less trouble...

Ground-based solar has one huge problem:  it's at the bottom of a murky
atmosphere on a rotating planet.  An SPS is in 24-hour 365-day sunlight.
(Well, not quite true -- short predictable eclipses at midnight around
the spring and autumn equinoxes -- but close enough.)  Ground-based
solar is actually producing useful power only about a third of the time
even if you assume excellent weather.  And you can't assume excellent
weather, not if you want generating stations near industrialized areas.
(Long-distance power transmission is inefficient and costly.)

The big win of an SPS is that you don't need a energy storage system.
Energy storage is immensely costly and is not improving very quickly.

Is this sufficient advantage to make up for higher installation and
maintenance costs?  ...possibly.  It is quite sensitive to assumptions
about costs of various things -- you can easily come up with an analysis
which says it doesn't pay, just by choosing pessimistic assumptions.
But it might.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

------------------------------

Date: Fri, 07 Aug 92 13:04:21 EDT
From: Tom <[e-mail]>
Subject: SPS fouling astronomy

John Roberts writes:

>> I don't know how much SPS would affect ground-based searches for asteroids
>> and comets, since they're basically searches for point sources that move
>> over time, without much need to exactly characterize those point sources
>> in the initial observations.

Fred ringwald replies:

>It probably would affect them adversely. The SpaceWatch telescope on
>Kitt Peak is used for asteroid searches in dark time, when the Moon is
>close to New. David Rabinowitz is a regular in the dining hall then (at
>dinner time, or when it's cloudy). During bright time, that telescope
>is used for a precision radial velocity program, to search for
>extrasolar planets.

>A telescope with a relatively short focal length and wide field of view
>will be easy affected by background; they don't even use the
>Burrell-Schmidt during bright time, unless there is an exceptionally
>bright comet around. Considering SPS are to ring the celestial equator,
>near the ecliptic where the asteroids are, this doesn't bode well.

>(My biggest problem with SPS still is: do you really think you can make
>a living at it? Seems to me that ground-based Solar would be amazingly
>cheaper and less trouble. Wind is making surprisingly good progress,
>too. And these contraptions are made of native materials, too: from
>Earth.)

About the resource-value.  Earth can't provide as much solar energy as is
available in space, as you know.  And even if you could get decent
solar power despite clouds, etc., you still have competing uses of the
land invloved.  Remember that the only use Romans had for that sticky,
smelly, dirty gunk that came out of the ground was sometimes as medicine.
But the mid-east is now making a hell of a living at it, and it's far more
limited (and polluting) than solar.  From muscles, to wood, to coal, to
oil, we've seen living standards increase with energy use.  SPS can
continue that trend.  France is reaching the limits of fission, fusion
is still ellusive, if not illusive, and I don't know of anything that can
provide more total energy than SPS.  Am I missing the boat, or is that
the situation?

About the sky-brightness:  I have found (sorry, forgot the ref.) that the
best designs for SPS use, not solar panels, but a heat sink and radiator,
with, essentially, a turbine between them to extract the energy from the
heat exchange.  In this case, won't the 'input' parts (those most likely
to reflect) be as dark as possible, to absorb as much heat as possible?
In that case, can't we expect them to appear rather dim from earth?

Or, if you decide to use large, thin-membrane reflectors for focus, wouldn't
it be just as easy to make, not a dish-shaped parabola, but rather a
cone-head shaped one, similar to x-ray or gamma detectors, thus keeping
stray reflected light to minimum, by containing it within?  Does SPS
_require_ lots of stray reflected light?  I have a telescope too.  Even
though I'd like to see SPS a reality, I like to see the reality that
includes galaxies, nebulae and clusters, too :-)

-Tommy Mac                     .  "                  +
.------------------------  +                      *       +
|   Tom McWilliams; scrub       ,     .                        "        +
|  astronomy undergrad, at     *       +;.     .  '             There is
| Michigan State University   '                      .    "   no Gosh!
|   [e-mail]                        '      ,   *
|       [phone]       ;  +  '                                 *
'-----------------------

------------------------------

Date: 7 Aug 92 14:37:27 GMT
From: Mark Purtill <idacrd!purtill>
Subject: What is the ASRM??
Newsgroups: sci.space,sci.space.shuttle

[e-mail] (Gary Coffman) writes:
>In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>>In article <[e-mail]> [e-mail] (James B. Pettengill) writes:
>>
>>>fred can't get off the ground without asrm.
>>
>>Unless they use Energia.

>Don't count on it. The CIS appear to be our friends today, but don't
>forget that only a year ago Soviet tanks were firing on civilians in
>the Baltics. International relations have a way of changing rapidly.
>Even if the CIS remains friendly, they can't yet be considered a
>reliable business partner. Dealing with them now would be like letting
>Frank Lorenzo run your airline. The odds of bankruptcy are too high.

Another point is that Energia has only flown a handful of times (two?
three?), and as I recall one of those flights was not exactly a
success (the payload ended up in the Pacific Ocean, although
apparently this was not directly related to Energia, but rather to the
secondary booster or something like that, i.e., the flight was a
success just like the teathered satellite deployment this week was).
As far as I know, there are no current plans to fly Energia again in
the near future, either, because the CIS space program hasn't got
enough money.
    For all of these reasons, I don't see any possibility of
shipping Fred to the CIS for launch in Energia (which would also
involve fun problems involving technology transfer), or even shipping
Energia here from a factory in the CIS to launch Fred.  What might be
possible is to buy the Energia plans and/or parts of the factory and
build Energia's in (say) Arkansas.

DISCLAIMER: There are no actual facts in this article, only the result
of having facts passed thru a special fact-distorting neural net (my
memory).

^.-.^ Mark Purtill, [e-mail]; uunet!idacrd!purtill. [phone].
((")) \@_: IDA/CCR-P, Thanet Road, Princeton NJ 08540;           [phone].

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End of Space Digest Volume 15 : Issue 084
------------------------------