Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v15_1/v15no101.txt

Text File | 1993-07-13 | 31KB | 754 lines

Date: Wed, 12 Aug 92 05:06:03
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #101
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 12 Aug 92       Volume 15 : Issue 101

Today's Topics:
         Beanstalks in Nevada Sky (was Re: Tethers) (2 msgs)
                Energiya's role in Space Station assem
              Energiya's role in Space Station assembly
                  ftp location of xsat and database
                   Germans drop European Shuttle ?
                     Marshal Krylov (SESS) visit
                     More second-hand info on TSS
              Need Shuttle Launch Dates Aug 20 - Sept 20
                          Parsecs? (2 msgs)
                        Seeding Mars with life
        SPS feasibility (WAS: SPS fouling astronomy) (2 msgs)
                    SPS fouling astronomy (3 msgs)
                  Star Trek (anti-)realism (2 msgs)
                          What about Saturn?

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: 12 Aug 92 03:06:34 GMT
From: [e-mail]
Subject: Beanstalks in Nevada Sky (was Re: Tethers)
Newsgroups: sci.space

"a free body that stays on its path without applying any thrust."

Let me rephrase this, what power of thrust would be needed?  Let's
say I wanted to keep a casino in orbit over Nevada for instance.

"nothing we have now is strong enough."

This is true.  Let me rephrase this, by the year 2026 do you think
we will have a material strong enough?

                                                        Eric Klien

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

Date: 12 Aug 92 03:14:39 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: Beanstalks in Nevada Sky (was Re: Tethers)
Newsgroups: sci.space

Although a permanent beanstalk over Nevada is not really feasible, as
Bill Higgins explains, I wonder about the potential of temporary ones.
Neat center of mass trick, and better than those misused by Wile E.
Coyote:

Fire a rocket into orbit. Have it play out a counterweight farther into
space, and then have another line with a grappling hook descent down
through the atmosphere (making the crack of a sonic boom). Make this
grappling hook intelligent, so it can find you, grab you, and pull you
into space.

Wow, what a ride! Makes me motion sick just to think of it. But a
version of it just might be useful for planetary sample return
missions...

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

Date: 11 Aug 92 23:50:32 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: Energiya's role in Space Station assem
Newsgroups: sci.space

[e-mail] (Matthew DeLuca) writes:

>In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:

>>Now suppose an Energia blows up? Let's assume the average payload can be
>>replaced for $4 billion and a replacement launch costs nothing (since this
>>is a commercial procurement and we only pay for success). Let's also assume
>>that the Energia blows up half the time (which seems a worse case to me).
>>This means we need to pay an additional $8 billion for the launch as the
>>worse case which raises the cost of Scenario B to $12 billion.

>>So now we have a Scenario A which costs $15 billion (assuming no failures)
>>and a Scenario B which costs $12 billion (assuming half the flights fail).

>>Which would you prefer?

>Scenario A, of course, since a failure in Scenario B results in the loss of
>a third or a half of the station hardware, resulting in a multi-year delay
>of the station, if not the complete abandonment of the project.

>Allen, why won't you understand that there is more involved than simple
>finance here?  You can 'save' $3 billion, but you better be happy spending
>that $3 billion on social welfare programs, because it sure as hell won't be
>spent in space.

If the project costs 3 billion more, that 3 billion won't be spent in
space either, won't be spent on other space projects, and won't be
spent on social welfare. The only way Congress would be able to get
that 3 billion for social welfare would be to shut the whole thing
down. Which they would do...

--
Phil Fraering [e-mail] where the x is a number from 1-5.
Phone: [phone]
SnailMail: 2408 Blue Haven Dr., New Iberia, La. 70560
"Sweet dreams and fine machines in pieces on the ground" - James Taylor

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

Date: 12 Aug 92 03:54:15 GMT
From: "James T. Green" <[e-mail]>
Subject: Energiya's role in Space Station assembly
Newsgroups: sci.space

[e-mail] (Gerald Cecil) speakith unto us:
>   knowing which half. ** Be terse: each line cost the Net $10 **
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Can you give sources for this claim
(Sorry it's not about space, but I don't know how to redirect it...)


/~~~(-: James T. Green :-)~~~~(-: [e-mail] :-)~~~\
|                                                               |
|    Slogans of two generations:  1972:  Question Authority!    |
|                                 1992:  Why Ask Why?           |

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

Date: 11 Aug 92 21:57:52 GMT
From: Greg Egan <[e-mail]>
Subject: ftp location of xsat and database
Newsgroups: sci.space

Can anyone help with the ftp location of xsat whch I believe predicts
weather satellite orbits and runs under X on sparcs etc.
Thanks,
       Greg.

--
Professor G.K. Egan
Director, Laboratory for Concurrent Computing Systems
Swinburne Institute, John Street, Hawthorn 3122, AUSTRALIA.
Phone: + 61 3 819 8167 Fax: + 61 3 819 6443 email: [e-mail]

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

Date: Wed, 12 Aug 1992 00:06:19 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: Germans drop European Shuttle ?
Newsgroups: sci.space

<[e-mail]> writes:

>Whilst skimming thru the TV channels last week, I caught sight of the
>German research minister, Riesenhuber, saying that Hermes was 'unacceptable'
>(not exact translation) to the German government in either manned or unmanned
>form. Two days later he showed up at the European Space Operations Centre to
>congratulate senior management on the fine job they'd done on Eureca. I'm
>cynical enough to believe that when politicians start throwing praise around,
>one should watch one's back. The ESA ministerial conference in November will
>probably contain some nasty surprises.........

Hey! He's probably just tired of the way the French have shut down all
launch vehicle research besides Hermes/Ariane V in ESA...

To wit, Saenger and Hotol...

--
Phil Fraering [e-mail] where the x is a number from 1-5.
Phone: [phone]
SnailMail: 2408 Blue Haven Dr., New Iberia, La. 70560
"Sweet dreams and fine machines in pieces on the ground" - James Taylor

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

Date: Wed, 12 Aug 92 02:19:58 GMT
From: Tom Roach <[e-mail]>
Subject: Marshal Krylov (SESS) visit
Newsgroups: sci.space

Last night I tuned across R. Moscow and I think I heard them say
that the Marshal Krylov (sister ship to the Space Event Support
Ship Marshal Nedelin) was in some sort of joint operation with the
Americans and was going to help recover some sort of object.

I also thought I heard them say the Krylov would be docking in Seattle
at the end of October (I think). Mention of the Coast Guard as well, I
think this offers a unique opportunity to see this giant vessel.

My hobby has been to monitor their communications (any Soviet maritime)
with special interest on the Academy of Science ships (NIS).  All very
fascinating and there is nothing I would love more than a chance to
go aboard the Krylov.  I'd gladly fly to Seattle just to see and
photograph her, and would be even happier to meet the crew or go
aboard.  Has anyone heard anything about this trip?

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

Date: Wed, 12 Aug 1992 00:57:07 GMT
From: "   Joseph F. Hull" <[e-mail]>
Subject: More second-hand info on TSS
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] (Chuck Shotton) writes:
>Running 12 miles of cable off a spool doesn't seem to be a particularly
>difficult task, even in zero G. ... Is this really anymore difficult to
>engineer than an elaborate fishing reel?  I seriously want to know how this
>cable mechanism was designed and tested and how such a simple mechanism can be
>so screwed up.

And [e-mail] (J. D. McDonald) Doug McDonald writes:
>But how hard would it be to carry several spooling systems, and try
>them all?

And [e-mail] (John Stevenson) writes:
>Well, Science News reports that the tether spooling mechanism was built
>and tested for $128 MILLION. ... It was Martin Marietta who built the
>spooling (NOT) system.

First, it is quite obvious that it is more difficult than engineering an elaborate fishing
reel, although it shouldn't be beyond us.  The cable mechanism was thoroughly tested to NASA
(remember them?  They`re the customer.  You know, the ones who have to authorize ALL
expenditures.) specifications, specifications intended to cover all operational conditions
except one, a microgravity environment with minimal tension on the tether, i.e., the
conditions that apply when the satellite is being deployed or retrieved very near the
Shuttle Orbiter.  Everyone involved knew that portion of the mission had not been fully
tested because it can't be tested on Earth (definitely not a microgravity environment, the
tether's own weight puts more tension on it than exists in the mission environment).

If you really think it is that simple, Chuck, why don't you bid for the deployer contract
for TSS-2.  Until you are willing to put that kind of money where your mouth is, please try
to be a little less derogatory.  BTW, no one yet knows exactly what it was that failed to
function properly, so maybe we could wait until after the Post-Flight Analysis.

The primary reason for not carrying several spooling systems is weight, although John
Stevenson's point about cost is well made.

--
       _   _
    /_    / ) / ) Jeff Hull          [e-mail]
   //_) -/- -/-   1544 S. Vaughn Cir
/_/ \_/ /   /      Aurora, CO 80012   303-977-1061

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

Date: Tue, 11 Aug 1992 22:53:14 GMT
From: Steven_Cohn <[e-mail]>
Subject: Need Shuttle Launch Dates Aug 20 - Sept 20
Newsgroups: sci.space

In article <[e-mail]>, [e-mail]
(keith schultz ldv/cl) wrote:
>
> Hi Netters,
>
>     The Subject says it all. My going to Florida and would like to
>     see a real live shuttle launch so if a kind soul would be kind
>     enough to give me the information or me to an e-mail site
>     I'd appreciate it very much !! Thanx for your patience, time and
>     efforts. I'm on the internet. See my adress bleow. Please
>     e-mail me since others may fell this to be a nuciance.
>
PLEASE POST THIS DATA!

Steven Cohn
Motorola CoveragePLUS Engineering
[e-mail]

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

Date: Wed, 12 Aug 92 01:30:40 GMT
From: Brian Kemper <[e-mail]>
Subject: Parsecs?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Richard Martin) writes:
|> Please forgive my ignorance, but what the heck is a parsec?
|> Richard.

OK, I'm going to take a stab at this one.  I know a parsec is a unit of
distance equal to roughly 3 light-years (a little more, I think).  I
*believe* it is defined as the distance at which a star "directly above"
the sun (i.e. so that the line from the sun to the star is perpendicular
to the earth's orbital plane) would have one arc-second of parallax due
to the earth orbiting the sun.  If I'm mistaken, I'd appreciate knowing
my error.

Brian


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

Date: 12 Aug 92 02:41:41 GMT
From: "Arlin B. Collins" <[e-mail]>
Subject: Parsecs?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Kemper) writes:
>In article <[e-mail]>, [e-mail] (Richard Martin) writes:
>|> Please forgive my ignorance, but what the heck is a parsec?
>|> Richard.
>
>OK, I'm going to take a stab at this one.  I know a parsec is a unit of
>distance equal to roughly 3 light-years (a little more, I think).  I
>*believe* it is defined as the distance at which a star "directly above"
>the sun (i.e. so that the line from the sun to the star is perpendicular
>to the earth's orbital plane) would have one arc-second of parallax due
>to the earth orbiting the sun.  If I'm mistaken, I'd appreciate knowing
>my error.
>Brian
>
 Brian's reply sounds fine to me, here is the definition quoted from
 'Facts on File Dictionary of Astronomy'
 parsec. Short for parallax second Symbol: pc. A unit of length normally
 used for distances beyond the solar system. It is the distance at which the
 semimajor axis of the earth's orbit subtends an angle of one arc second.
 It is thus the distance at which a star would have an *annual parallax of
 one arc second.  A star with a parallax of 'p' arc seconds is at a distance
 'd' parsecs, given by  d=1/p (accurate up to distances of about 30pc).
 One parsec equals  30.857x10**12 km, 206265 astronomical units, and
 3.2616 light-years.
 --

--
Arlin B Collins     CompuServe:  INTERNET:[e-mail]   :-)

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

Date: 12 Aug 92 01:43:36 GMT
From: John Roberts <[e-mail]>
Subject: Seeding Mars with life
Newsgroups: sci.space

-From: [e-mail] (David Knapp)
-Subject: Re: Seeding Mars with life
-Date: 11 Aug 92 15:38:58 GMT
-Organization: University of Colorado, Boulder

-In article <[e-mail]> [e-mail] writes:
->Even the "vent" organisms are exploiting the chemical gradient set up
->by photosynthesis (they oxidize the reduced chemicals coming out of the
->vents), and are therefore not completely geothermally powered.

-The do not comsume photosythesized materials. (at least according to National
-Geographic...)

I think the point Paul's trying to make is that the organisms take advantage
of oxidizing chemicals (perhaps oxygen among them) produced by photosynthetic
life. I don't know enough on the subject to confirm or deny that. I have
read that some bacteria get their energy by some chemical change in iron
compounds, and that others get it by converting one sulfur compound to another,
and it would be helpful if Paul would comment on whether both of these are
tied in with compounds produced by photosynthesis.

-If we get cocky and think we can forcast everything that might ever happen
-concerning life on another planet or moon, we could quite easily destroy our
-ability to detect it or study it.  You might not think that would be a waste,
-but luckily, NASA and ESA (and many others) do. For the cost of creating a
-sterilization policy, we insure a better possiblity of finding life if it
-exists on Mars.  We've already mucked up this planet enough with ego-
-centricity, I don't think it's a bad thing at *all* to treat the only other
-planet in our solar system, which might be able to support humans, with kid
-gloves.

If there were some cheap and easy way to get humans to Mars in the near
future, I'd say we should forget about Mars contamination issues, and go
for it. However, that does not appear to be the case, so an argument can
be made in favor of playing it safe with unmanned spacecraft.

John Roberts
[e-mail]

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

Date: 11 Aug 92 23:59:51 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: SPS feasibility (WAS: SPS fouling astronomy)
Newsgroups: sci.space

I have to reply this way because you never know if Dennis
Wingo's email address is going to work.

Basically: the war (or wars) in Ethiopia are what caused (or greatly
greatly aggravated) the famines.

Maslow's "hierarchy of needs" is IMHO not very accurate. For more
on this, read some of Eric Hoffer's early work...


--
Phil Fraering [e-mail] where the x is a number from 1-5.
Phone: [phone]
SnailMail: 2408 Blue Haven Dr., New Iberia, La. 70560
"Sweet dreams and fine machines in pieces on the ground" - James Taylor

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

Date: 12 Aug 92 04:19:45 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: SPS feasibility (WAS: SPS fouling astronomy)
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] writes:

> I don't usually go this orbital on a post like that but somtimes the arrogance
> and presumption of the poster just begs for it.

Look who's talking!

At least when presented with a sound argument, I can change my mind.
Can you?

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

Date: 12 Aug 92 01:18:47 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: SPS fouling astronomy
Newsgroups: sci.space

Actually, this is a very easy calculation.

Take W(in) to be the Solar constant, 1340 W/m^2;
take W(out) to be the satellite's reflected flux, seen at Earth;

take a to be the albedo of the satellite,
take A to be its area, and
take r to be its distance from Earth.

Assume satellite is same distance from Sun as Earth;
it will be, on the average, plus the maximum difference is <1%.
Also ignore Sun angle, i.e. phasing, and go for just an upper limit;
i.e., find the maximum brightness.

Then
W(in)/W(out) = aA/r^2

And it's easy enough, from this ratio, to estimate the apparent
magnitude of the satellite, given V(Sun) = -26.7. If you don't believe
me, try this calculation yourself on the Moon.

For a satellite in geostationary orbit, where most SPS designs have
them,
of 10 km^2 area (I believe a 1977 NASA design favored by O'Neill was
this size),
and albedo a = 1, at full phase, it'd shine at V = -6. Brighter than
Venus!

More realistically, take a = 0.07, that of Lunar basalt (a Solar power
satellite is supposed to absorb energy, after all: it'd be silly to
make one as reflective as a mirror), which brings it to V = -3.0. Less
bright than Venus, at its brightest, but brighter than Jupiter.

Now, a Solar power satellite would probably be blackened on purpose, to
absorb more energy, so as a lower limit on albedo, take a = 0.01. This
gives V = -1.0, comparable to the brightest stars.

And now for the really interesting part:
at 10 km^2, and A = 0.01, an SPS would gather in the neighborhood of
13.4 GW. So, ignoring losses (large assumption here), you'd need about
1000 of them to run the world (assuming rather profligate energy use,
which deflates the large loss-free assumption). That makes about 500
SPSs in anyone's sky at once (and material for a bad pun: a
Con-Ed-stellation), strung along the celestial equator. Another 29%
(1-sqrt(2)/2) of the light would be cut out by phasing. (You were
wondering where that'd come up, weren't you?) So, the total integrated
brightness is about V = -9, about 3% that of a Full Moon.

The sky brightness at Kitt Peak has increased by about 7% in recent
years (Pilachowski et al. 1989, Pub. Astr. Soc. Pacific, 101, 707) and
I saw the Milky Way very well up there in 1988-1992. So, even with a
ring of SPSs, you probably could still see the Milky Way, from a dark
site, and not where it crosses the equator (Jupiter alone trashes the
Gegenschein; at least it did, last February). Also, the objection that
"there'd be nowhere on Earth you could get away from the handiwork of
humans - no remaining true wilderness" isn't really true: try Alaska
(bonus point: tell me why).

Well, I never thought I'd turn into a proponent of SPS, but safety and
esthetics actually do appear manageable (see other recent posts). The
issue of COST is unresolved, however, but come to think of it, is there
any reason SPS *must* be a mega-engineering project? Might there be
some way of doing it simply?

Fred Ringwald
Department of Physics & Astronomy
Dartmouth College
Hanover, NH 03755-3528 U.S.A.

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

Date: 12 Aug 92 03:27:47 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: SPS fouling astronomy
Newsgroups: sci.space

Actually, this is a very easy calculation.

Take W(in) to be the Solar constant, 1340 W/m^2;
take W(out) to be the satellite's reflected flux, seen at Earth;

take a to be the albedo of the satellite,
take A to be its area, and
take r to be its distance from Earth.

Assume satellite is same distance from Sun as Earth;
it will be, on the average, plus the maximum difference is <1%.
Also ignore Sun angle, i.e. phasing, and go for just an upper limit;
i.e., just find the maximum brightness.

Then
W(out)/W(in) = aA/r^2

It's easy enough, from this ratio, to estimate the apparent
magnitude of the satellite, given V(Sun) = -26.7. If you don't believe
me, try this calculation yourself on the Moon.

For a satellite in geostationary orbit, which most SPS designs have,
of 10 km^2 area (the size of a 1977 design favored by O'Neill),
and albedo a = 1, at full phase, it'd shine at V = -6.
Brighter than Venus!

More realistically, take a = 0.07, that of Lunar basalt. A Solar power
satellite is supposed to absorb energy, after all: it'd be silly to
make one as reflective as a mirror. This brings it to V = -3.0. Less
bright than Venus, at its brightest, but brighter than Jupiter.

Now, a Solar power satellite would probably be blackened on purpose, to
absorb more energy, so as a lower limit on albedo, take a = 0.01. This
gives V = -1.0, still comparable to the brightest stars.

And now for the really interesting part:

At A = 10 km^2, and a = 0.01, an SPS would gather in the neighborhood
of
13.4 GW. So, ignoring losses - large assumption here - you'd need about
1000 of them to run the world, assuming rather profligate energy use,
which deflates the large loss-free assumption. That makes about 500
SPSs in anyone's sky at once, strung along the celestial equator, and
material for a pun: a Con-Ed-stellation. Another 29% (1-sqrt(2)/2) of
the light would be cut out by phasing. (You were wondering where that'd
come up, weren't you?) So, the total integrated brightness is about V =
-9, about 3% that of a Full Moon, for a necklace about the celestial
equator.

The sky brightness at Kitt Peak has increased by about 7% in recent
years (Pilachowski et al. 1989, Pub. Astr. Soc. Pacific, 101, 707) and
I saw the Milky Way very well up there in 1988-1992. So, even with a
ring of SPSs, you probably could still see the Milky Way, from a dark
site, and not where it crosses the equator (Jupiter alone trashes the
Gegenschein; at least it did, last February). Also, the objection that
"there'd be nowhere on Earth you could get away from the handiwork of
humans - no remaining true wilderness" isn't really true: try Alaska
(bonus point: tell me why).

Well, I never thought I'd turn into a proponent of SPS, but safety and
esthetics actually do appear manageable (see other recent posts). The
issue of COST is unresolved, however, but come to think of it, is there
any reason SPS *must* be a mega-engineering project? Might there be
some way of doing it simply?

Fred Ringwald
Department of Physics & Astronomy
Dartmouth College
Hanover, NH 03755-3528 U.S.A.

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

Date: 12 Aug 92 04:49:59 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: SPS fouling astronomy
Newsgroups: sci.space

Actually, this is a very easy calculation.

Take W(in) to be the Solar constant, 1340 W/m^2;
take W(out) to be the satellite's reflected flux, seen at Earth;

take a to be the albedo of the satellite,
take A to be its area, and
take r to be its distance from Earth.

Assume satellite is same distance from Sun as Earth
it will be, on the average, plus the maximum difference is <1%.
Also ignore Sun angle, i.e. phasing, and go for just an upper limit;
i.e., just find the maximum brightness.

Then
W(out)/W(in) = aA/r^2

It's easy enough, from this ratio, to estimate the apparent
magnitude of the satellite, given V(Sun) = -26.7. If you don't believe
me, try this on the Moon. You should get V(Moon) = -12.7.

For a satellite in geostationary orbit, which most SPS designs have,
of 10 km^2 area (the size of a 1977 workshop design favored by
O'Neill),
and albedo a = 1, at full phase, it'd shine at V = -6.
Brighter than Venus!

More realistically, take a = 0.07, that of Lunar basalt. A Solar power
satellite is supposed to absorb energy, after all: it'd be silly to
make one as reflective as a mirror. This brings it to V = -3.0. Less
bright than Venus, at its brightest, but brighter than Jupiter.

Now, a Solar power satellite would probably be blackened on purpose, to
absorb more energy, so as a lower limit on albedo, take a = 0.01. This
gives V = -1.0, still comparable to the brightest stars.

And now for the really interesting part:

At A = 10 km^2, and a = 0.01, an SPS would gather in the neighborhood
of
13.4 GW. So, ignoring losses - large assumption here - you'd need about

1000 of them to run the world, assuming rather profligate energy use,
which deflates the large loss-free assumption. That makes about 500
SPSs in anyone's sky at once, strung along the celestial equator, and
material for a pun: a Con-Ed-stellation. Another 29% (1-sqrt(2)/2) of
the light would be cut out by phasing. (You were wondering where that'd
come up, weren't you?) So, the total integrated brightness is about V =
-9, about 3% that of a Full Moon, for a necklace about the celestial
equator.

The sky brightness at Kitt Peak has increased by about 7% in recent
years (Pilachowski et al. 1989, Pub. Astr. Soc. Pacific, 101, 707) and
I saw the Milky Way very well up there in 1988-1992. So, even with a
ring of SPSs, you probably could still see the Milky Way, from a dark
site, and not where it crosses the equator (Jupiter alone trashes the
Gegenschein; at least it did, last February). Also, the objection that
"there'd be nowhere on Earth you could get away from the handiwork of
humans - no remaining true wilderness" isn't really true: try Alaska
(bonus point: tell me why).

Well, I never thought I'd turn into a proponent of SPS, but safety and
esthetics actually do appear manageable (see other recent posts). The
issue of COST is unresolved, however, but come to think of it, is there
any reason SPS *must* be a mega-engineering project? Might there be
some way of doing it simply?

Fred Ringwald
Department of Physics & Astronomy
Dartmouth College
Hanover, NH 03755-3528 U.S.A.

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

Date: 12 Aug 92 01:38:24 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: Star Trek (anti-)realism
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] (Kenneth Ng) 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.

Ah, yes, and then there's the view of a galaxy from outside (e.g., end
of the second Star Wars movie). Never mind that the surface brightness
would still be low, not unlike that of the Milky Way! Or, more like
Andromeda...

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

Date: 12 Aug 92 02:45:28 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: Star Trek (anti-)realism
Newsgroups: sci.space

In article <[e-mail]>
Nicholas C. Hester <[e-mail]> writes:

> Being mostly ignorant about these things, what would an asteroid field
> look like if one flew into it?  I always assumed that it would be alot
> calmer, w/o the asteroids tumbling like in StarWars.

Probably you wouldn't even notice it. Even the scene in 2001 is an
exaggeration (one of still impressively few, neglecting the Turing
test). It'd be unlikely you'd ever come close enough to a large
asteroid to see it look like a rock. Pioneer 10 and the subsequent
craft that did fly through it gave surprisingly low counts of even
dust. You're right about the tumbling, too: most asteroid rotation
rates are hours-to-days long.

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

Date: 12 Aug 92 01:34:02 GMT
From: "Richard A. Schumacher" <[e-mail]>
Subject: What about Saturn?
Newsgroups: sci.space

An exactly duplicate of Saturn, using the same prints?
More than it would cost to do something from scratch, and much more
than it would cost to do something based on Saturn. The problem
is that all the tooling, and hundreds of subcontractors who knew
just how to make widget X out of alloy Y using their own process
Z, are gone. It's a loooong way from a set of prints to a working
system, even if you used to know how to get there...

-----------
Forget about ultimate truths! Just abandon your preconceptions!
                        -Lao Tse

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Date: 
P
From: 
P

Organization: University of Maine System
Date: Tuesday, 11 Aug 1992 18:03:15 EDT
From: "Nicholas C. Hester" <[e-mail]>
Message-Id: <[e-mail]>
Newsgroups: sci.space
Subject: Re: Star Trek (anti-)realism
References: <[e-mail]:
 <[e-mail]>
 <[e-mail]>
Lines: 15
Sender: [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]>, [e-mail] (Kenneth Ng) says:
>
>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.

Being mostly ignorant about these things, what would an asteroid field
look like if one flew into it?  I always assumed that it would be alot
calmer, w/o the asteroids tumbling like in StarWars.
___

    Nick Hester                     "Time time time
[e-mail]                 for another peaceful war..."
[e-mail]                     - Warren Zevon
                                       "Roland the Headless Thompson Gunner"

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End of Space Digest Volume 15 : Issue 101
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