Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_2/V15NO213.TXT

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Date: Fri, 18 Sep 92 05:00:43
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #213
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 18 Sep 92       Volume 15 : Issue 213

Today's Topics:
                  Clinton and Space Funding (2 msgs)
                      Craters of Venus Inventory
                       Drop nuc waste into sun
                   Ethics of Terra-forming (2 msgs)
                      Hubble's constant (2 msgs)
              Ion for Pluto Direct was Re: Pluto Direct
                             Moving Venus
                         Nasa's Apollo rerun
               Pluto Direct Propulsion Options (2 msgs)
                        Pulsing rocket engines
 PUTTING VENUS IN AN ORBIT SIMILAR TO THE ORBIT OF THE EARTH (2 msgs)
             Space Platforms (political, not physical :-)
             Two-Line Orbital Element Set:  Space Shuttle

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

Date: 16 Sep 92 14:33:09 GMT
From: [e-mail]
Subject: Clinton and Space Funding
Newsgroups: sci.space,sci.astro

In article <[e-mail]>, [e-mail] (Jon J Thaler) writes:
> [e-mail] (Doug Mohney) says:
>
> I suspect that the spin-off argument is about as bogus for military research
> as it is for other fields (eg, the SSC).  For example, unclassified work
> on laser guide stars was proceeding at the same time that the SDIO was
> pursuing its own program.  Needless to say, the budget for the former was
> vastly smaller than for the latter.  My conclusion:  If you want some benefit,
> then go for it, but don't hope that by doing some unrelated work at much
> greater expense you'll be lucky.
>

The only reason that the laser guide star work was declassified is that they've
got a better and more effective method already developed.

Research procedes better when conducted in an open unclassified environment.
This is one *good* reason why military research does not generally work as
well.

--
================================================================================
Dave Clements, Oxford University Astrophysics Department
================================================================================
clements @ uk.ac.ox.vax            |  Umberto Eco is the *real* Comte de
dlc      @ uk.ac.ox.astro        |           Saint Germain...
================================================================================

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

Date: 16 Sep 92 13:43:05 GMT
From: "Ethan T. Vishniac" <ut-emx!ethan>
Subject: Clinton and Space Funding
Newsgroups: sci.space,sci.astro,talk.politics.space,alt.politics.bush,alt.politics.clinton

The summary says it all.  If there were some content to this then
some political newsgroup would do.  As it is, then only
talk.liberal.bashing would seem appropriate.  Maybe Mr. Vignes
could create such a group.  In any case there seems to be nothing
in this relevant to astronomy.
--
"Quis tamen tale studium, quo ad primam omnium rerum causam evehimur,
tamquam inutile aut contemnendum detractare ac deprimere ausit?"-Bridel
Ethan T. Vishniac, Dept. of Astronomy, The University of Texas at Austin
Austin, Texas, 78712                   [e-mail]

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

Date: 17 Sep 92 11:03:49 GMT
From: Ron Baalke <[e-mail]>
Subject: Craters of Venus Inventory
Newsgroups: sci.space,alt.sci.planetary

                              ====================
                                Craters of Venus
                               September 16, 1992
                              ====================

     The USGS inventory of the craters of Venus is now available as a text
file.  This file contains the text of Schaber's Appendix A from his
"JGR-Planets" paper, but it can easily be turned into a database or
spreadsheet.  The file can be retrieved using anonymous ftp from:

        ftp:      ames.arc.nasa.gov (128.102.18.3)
        user:     anonymous
        cd:       pub/SPACE/MAGELLAN
        file:     craters.txt
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Quiet people aren't the
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/  |_|/       |_____|/                     | much.

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

Date: 17 Sep 92 06:54:18 GMT
From: Nick Janow <[e-mail]>
Subject: Drop nuc waste into sun
Newsgroups: sci.space

[e-mail] (John Stevenson) writes:

> Why not drop all the longlived nuclear waste into the sun to permanently
> dispose of it. The waste is a *very* expensive problem that will otherwise be
> with us (children's children to the nth power) for along time.
>
> ....
>
> So, oh wise ones, enlighten me. What am I missing? Thanks

Simple: that mass of transuranics isn't waste, it's a valuable resource we
simply haven't developed a market for...yet.  Politicians, supported by
ignorance, have made it difficult to do anything with the "waste".  From an
engineering standpoint, that "waste" is a compact source of high-level energy,
with many uses.  It can sterilize/preserve foods better than toxic chemicals,
it can provide safe heat for remote areas, it could sterilize sewage, or it
could be "burned" in a different reactor, providing more energy.

Sending nuclear waste into the sun is like dumping platinum in the ocean
because it isn't the metal you wanted at the time (gold).  Was it the Spaniards
who did that off the S.American coast?  Think of how many people threw out
"trash" such as baseball trading cards, or any other collectibles.


"They threw away transuranics?  WERE THEY CRAZY?"

--

[e-mail]

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

Date: Thu, 17 Sep 1992 03:51:22 GMT
From: David Knapp <[e-mail]>
Subject: Ethics of Terra-forming
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Thomas H. Kunich) writes:
>>We don't know if there is or if there isn't any life on Mars.
>
>We clearly need to find out before we do any major alterations.
>
>>What is to prevent there being some sort of life-form analogous to
>>the vent creatures of the deap oceans living subterrameanly at
>>some depth at which water, heat and chemical sustanance is available
>>from interior heating?
>
>What is to prevent such life on Earth?  Maybe we are unknowingly wiping
>it out right now.  We always have to act on imperfect knowledge, but we
>should make a reasonable effort.
>
>Consider also that any present life on Mars is probably having a hard
>time of it.  Maybe some environmental changes are just what is needed
>to *save* it from extinction.
>
>>What ever life there might be on Mars, or anywhere else for that matter,
>>at least has the right to exist. Is man God, to destroy other life-forms
>>without much measured forethought?
>
>Actually, the correct line is "Is man Nature?".  Nature recognizes no
>"right to exist"; extinction was a routine event long before we arrived.

But one question most people forget to ask is 'who was doing the extincting?'

How many species do you know of that:
1) Can think about long term consequences of their actions.
2) Are capable of at least some degree of terraforming.
3) Causes mass extinctions on a daily basis.
4) Should, many times, "know better"
4) Has the capability to wipe out all life currently known in one fell swoop.
5) Controls their enviroment, in all aspects, to suit their needs.
6) Expands to live in every environment on the planet.
7) etc. The list can get very long. Point to anything that differentiates
   us from all other life.

After considering all these things, we have to conclude that mankind is not
just your average-joe species is just carrying a long with the rest of them.
We are a *major* influence here like no othe species before us. Mankind
is most certainly a special case when you point to 'nature.'

>Are we Nature?  Well, yes, we're part of it.  We should act cautiously,
>especially given our relative ignorance

That is the understatment of the day (IMO) The power that mankind currently
has along with the collective stupidity he posesses, I must liken to
giving a toddler an AK-47 and hoping for the best. You can see the
bullet holes all around you.

>, and bearing in mind that it's
>hard to reverse extinction... but there is nothing morally wrong about
>making changes.  Nature does it all the time.

*We* decide what is moral. Just one man saying so isn't enough. *We* are
also not nature. What you see in nature is nothing near the result of a
'relatively ignorant' species.

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

Your .sig is quite relevant here.



--
David Knapp                                      University of Colorado, Boulder
Perpetual Student                                   [e-mail]

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

Date: 17 Sep 92 07:25:24 GMT
From: Bertil Jonell <[e-mail]>
Subject: Ethics of Terra-forming
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (David Knapp) writes:
>But one question most people forget to ask is 'who was doing the extincting?'
>
>How many species do you know of that:
>3) Causes mass extinctions on a daily basis.
>5) Controls their enviroment, in all aspects, to suit their needs.
>6) Expands to live in every environment on the planet.

  All species that have the capability of doing so.

  To make a very silly example, if mooses suddenly would become capable of
living anywhere, escape any predator and plan for the future, I'd expect them
to use all this (especially the last thing) to exapand and spread to their
utmost limits.

>After considering all these things, we have to conclude that mankind is not
>just your average-joe species is just carrying a long with the rest of them.

  Consistent along the latter history of mankind has been an inflated sense
of self-importance. It seems to have started with the 'in gods image' idea,
moved on to 'crown of creation' and 'lord of nature' and then on to 'most
dangerous animal', 'controls their enviroment, in all aspects, to suit their
needs', 'expands to live in every environment on the planet' and 'most
disruptive influence in the history of the planet'.

  The common theme of all this is obviously a self-congratulatory "We're
Special!"(1).

>We are a *major* influence here like no othe species before us.

  Changed the environment more than the blue-green algae did?

reformatted quotes:
>....Mankind is most certainly a special case when you point to 'nature.'..
>..The power that mankind currently has....You can see the bullet holes all
>around you....*We* decide what is moral....What you see in nature is nothing
>near the result of a 'relatively ignorant' species.

>David Knapp                                      University of Colorado, Boulder

(1) This also has some connection to the question "What's the difference
    between George Bush and Noam Chomsky?" where the correct answer is that it
    is very small. Both believe that the US is the mightiest country in the
    world. Both believe that US domestic politics drives all international
    politics. Both believe that the world as it looks today is a creation of
    the US.
    1/2:)

-bertil-
--
"It can be shown that for any nutty theory, beyond-the-fringe political view or
 strange religion there exists a proponent on the Net. The proof is left as an
 exercise for your kill-file."
"This is the famous Hasan B Mutlu-trigger, insert it in your .sig file today!"

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

Date: 16 Sep 92 15:25:41 GMT
From: Richard J Brooks <[e-mail]>
Subject: Hubble's constant
Newsgroups: sci.space

Hi Gang

I read this past week about a researcher stating that some measurements
indicate that the HUBBLE constant is changing with time.  The acticle
stated that the change was fast enought that a remeasurement in 2 or 3 year
would verify this.

Could any of you on the NET comment about this.

(As a side comment - If my memory is correct, Hubble's constant is used
in determining distances in space.  Does this mean that the size of the
universe is changing?)


-----------------------------------------------------------------------------
 Richard J Brooks                    | To know wisdom and instruction
 [e-mail] | To discern the saying of understanding
                                     | Proverbs 1:2
-----------------------------------------------------------------------------

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

Date: 17 Sep 92 01:21:16 GMT
From: Steinn Sigurdsson <[e-mail]>
Subject: Hubble's constant
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Richard J Brooks) writes:


   Hi Gang

   I read this past week about a researcher stating that some measurements
   indicate that the HUBBLE constant is changing with time.  The acticle
   stated that the change was fast enought that a remeasurement in 2 or 3 year
   would verify this.

   Could any of you on the NET comment about this.

Sure, not only is the Hubble "constant" (sic) changing
in time, the value is in fact oscillating, the frequency of
oscillation increasing with time while the amplitude appears
to have decreased slightly... ;-)


Seriously: there is a deceleration paramater, a non-zero value
of which can be considered equivalent to a changing hubble constant,
and it might even be detectable this decade, however, there is (still)
and uncertainty of factor two in the present value of the hubble
constant, so don't bet on it.

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |

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

Date: Thu, 17 Sep 1992 04:36:27 GMT
From: Dave Tholen <[e-mail]>
Subject: Ion for Pluto Direct was Re: Pluto Direct
Newsgroups: sci.space

Greg Macrae writes:

> Well, you're actually wrong on all counts.  The biggest problem that ion
> thruster technology faces is being unproven in the field.  In a mission
> that is such high risk as planetary robotic exploration, no one want to
> be the first to use ion propulsion.  For a Pluto mission, ion thrusters
> enable the mission.  The Aerospace Analysis Office here published a study
> that showed ion thrusters could place twice the payload in orbit (or on)
> Pluto that chem. rockets could fly past Pluto and ion did it in less than
> 1/2 the time with the same Leo mass!  The study assumed a Jupiter slingshot
> for the chem. system and not for ion.  In general, ion has time and mass
> advantages for all missions beyond the asteroid belt.  At Pluto's orbit,
> the advantage is very significant.  As for on-going work with ion thrusters,
> the focus is currently on station keeping and other near earth satellite
> applications in hopes of establishing the track record of success required
> for serious consideration for interplanetary missions.  Research is funded at
> fairly low levels at both Lewis Research Center and JPL.  Hughes is marketing
> flight qualified ion thrusters for station keeping use.

The current Pluto flyby mission design calls for chemical rockets and NO
Jupiter flyby, and the flight time is about seven years.  Your posting seems
to be claiming that an ion drive can place twice the payload into orbit around
Pluto with a flight time of about 3.5 years.  If this were true, I'm quite
certain that the Outer Planets Science Working Group would have heard of it.

Agreed that ion has FLIGHT time and mass advantages beyond the asteroid belt,
but once we get there, we'd like to have some time to study the object, and
a fast ion drive flyby provides less time to do that.  True, ion can be used
to slow down, even enough to go into orbit, but then the flight time increases,
and the estimates we were given were much, much longer than 3.5 years.

And I wouldn't go so far as to say that ion drive enables a Pluto mission.
The implication is that without ion drive, you can't do a Pluto mission, and
that simply isn't true.  We've looked at several mission options all based
on chemical rockets.  Many of them are quite attractive.  Ion drive options
are also attractive, but riskier.  Therein lies the Catch 22.

Regarding my comment about development of ion drive not being funded, I was
referring to the type of long duration mechanism proposed for the TAU mission.
The station-keeping application is rather different than that needed for
interplanetary propulsion, which is also long duration, continuous duty cycle.

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

Date: Wed, 16 Sep 1992 22:44:59 GMT
From: David Knapp <[e-mail]>
Subject: Moving Venus
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (pete) writes:
>Hey, that's what we like to see; a good practical civil
>engineering problem. (^: So hey: here's the cheap easy way
>to do it (and you get Mars in a warmer orbit as a bonus).
>Just build a whole bunch of big electron accelerators,
>and fire off kiloamps of e+ at Mars and a similar quantity
>of e- at Venus. After a few centuries of constant current,
>the E field will start pulling the 2 planets toward each
>other, moderating both their climates. Or maybe it will
>just charge up their atmospheres, causing Venus to lose
>a whole lot of unwanted cloud cover by repulsion.
>      This also guarantees lots of jobs for generations
>of us accelerator folk.   (^: (^: (^:
>
>===========================================================================
>Now what we really need is a scheme                    Pete Vincent
>for Mars and Venus to trade atmospheres.
>


It's good to finally see some reasonable arguments here!


--
David Knapp                                      University of Colorado, Boulder
Perpetual Student                                   [e-mail]

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

Date: 16 Sep 92 07:30:13 GMT
From: "John A. Weeks III" <[e-mail]>
Subject: Nasa's Apollo rerun
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Craig Keithley) writes:
> The gist of the report was that we goofed in our choice of going to the
> moon.  During the late 50s and early 60s, we were faced with the choice of
> developing things like DynaSoar and MOL (these were Air Force) or going for
> the moon shot.

In retrospect, I think that there are a lot of people who feel this way.
It is depressing to think of what might have been if the space program
had continued along the X-15 path to space rather than the man-in-a-can
program.  Then again, one has to keep in mind that the US went to the
moon only because we thought the Soviets would beat us to it.  No cold war,
no moon shot.  I doubt that the US would have spent a similar amount of
money on space without the cold war or the race to the moon.  The real
crime is that the US spent a ton of money going to the moon rather than
spending the money on a space program.  Once the moon goal was reached,
everything came to a halt and the Apollo program was scrapped.

-john-

--
==============================================================================
John A. Weeks III        [phone]            [e-mail]
Newave Communications, Ltd.                ..!uunet!tcnet!newave!john

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

Date: 17 Sep 92 01:36:58 GMT
From: Dave Tholen <[e-mail]>
Subject: Pluto Direct Propulsion Options
Newsgroups: sci.space,sci.astro,alt.sci.planetary

> Wonder if there would be "snow" storms when Pluto's atmosphere freezes out,
> or would just form frozen "dew" on the surface.  Maybe both, as the gas
> with the higher freezing point "snows" out before the gases with lower
> freezing points condense out.  (Do I remember correctly that there are
> more than one gas in Pluto's atmosphere?)

"Storm" is a relative term.  Pluto's atmosphere is so thin that you'd never
get anything like what we have on Earth.  On the other hand, Voyager showed
streaks on Triton, apparently driven by winds, even though Triton's
atmosphere is about as thin as Pluto's.  Whether Pluto also has winds is an
excellent question.  If the surface is isothermal, which could be the case
if methane frost is everywhere, then there isn't much of a mechanism to
drive winds, but if the darker regions are exposed rock, for example, then
temperature differences could exist, thereby driving some weather on Pluto,
so you might have something more than just the equivalent of dew forming.

Yes, there are several gases in Pluto's atmosphere.  Methane, nitrogen, and
carbon dioxide have all been detected spectroscopically (the latter two
only very recently).  The vapor pressure of nitrogen is highest, followed
by carbon dioxide, so nitrogen is probably the dominant gas.

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

Date: 17 Sep 92 01:41:42 GMT
From: Dave Tholen <[e-mail]>
Subject: Pluto Direct Propulsion Options
Newsgroups: sci.space,sci.astro

Josh Hopkins writes:

> Do we need to worry about pulling another Titan?  It would be kind of
> embarrassing to dedicate a half billion, two probes and ten years of ops, only
> to find out that Pluto's atmosphere is opaque :)

I can assure you that Pluto's atmosphere is not opaque.  At the limb, the
optical depth might approach unity if Jim Elliot's haze layer model is
correct (and there are good chances that it isn't correct), but at normal
incidence, it is rather transparent.  Why do you think we see a lightcurve,
and a substantial one at that?

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

Date: 17 Sep 92 05:36:20 GMT
From: Dave Rickel <[e-mail]>
Subject: Pulsing rocket engines
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Michael K. Heney) writes:
|> In article <urf.716491099@sw2001> [e-mail] (Urban F) writes:
|> >Ali AbuTaha, of Dynamic Transients, is claiming that
|> >pulsing-engine technology could enable the Shuttle to carry a
|> >payload of 105.500 kg, as apart from 29.500 today, and also that
|> >an Ariane 4:s first stage could become so efficient as to make it
|> >a SSTO vehicle.
|>
|> I saw an abstract of a paper he wrote for the World Space Congress here in
|> DC last month.  He talks about "rectifying" the engine thrust to effectively
|> double the Isp - for the SSME, that moves it from 455 to the 900 sec range.
|> He claims (correctly; I assume) that you could launch without the SRBs,
|> making the shuttle/ET combination an SSTO.


Such Isp increases are bogus.  It might be that he thinks he can get a
dramatic increase in the thrust:weight ratio of the engines--a ratio of
around 200:1 should be about right for eliminating the SRBs.  The SSMEs have
a thrust:weight ratio of about 60:1.


david rickel
[e-mail]

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

Date: 17 Sep 92 00:58:47 GMT
From: David Smith <[e-mail]>
Subject: PUTTING VENUS IN AN ORBIT SIMILAR TO THE ORBIT OF THE EARTH
Newsgroups: sci.space

I think we've found Dan Quayle's advisor on the Mars speech!


--
David L. Smith
[e-mail] or [e-mail]

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

Date: Thu, 17 Sep 92 14:07:59 BST
From: [e-mail]
Subject: PUTTING VENUS IN AN ORBIT SIMILAR TO THE ORBIT OF THE EARTH

> sustaining ecology on the planets (like Venus or Mars) whose
present cosmic
> parameters, to begin with do not allow the existence of life on
them, seems
> improbable and impractical.
>


Your statement is not correct. The current states of Mars and Venus,
while associated with their origin at a closer distance to the sun
are not fully constrained by that location. Even if moved, the dense
CO2 atmosphere and H2 deficit will still be there for Venus. Venus
would cool, but something has to be done to get rid of (or bury) the
excess carbon. If Venus had been at Earth orbit billions of years
ago, before it lost it's water, geochemistry might have done the
trick. But it unfortuneately too late for that.

Not to mention which, you could have nasty side effects like causing
other planets to leave the solar system. As recent papers have shown,
all 9 planets are in chaotic orbits. There are two time constants
involved, neither of which has been identified. The solar system
exhibits long term stability nonetheless, so it could be that only
those proto planetary bodies which were at the right place relative
to other protoplanets survived, ie were not kicked out of the solar
club.

If you moved Venus, all the resonances change drastically and there
is no certainty whatever that the end result would look any thing at
all like the current solar system. Of course, the Earth might make a
nice Interstellar Generation Spaceship if we get fusion power going
soon enough...



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

Date: 17 Sep 92 06:55:33 GMT
From: Bertil Jonell <[e-mail]>
Subject: Space Platforms (political, not physical :-)
Newsgroups: sci.space,talk.politics.space,alt.politics.libertarian,alt.war

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>* Privatize the radio spectrum and orbital slots, and disavow all
>  treaties (Sea, Moon, Antartica, etc.) that prohibit private
>  property and enterprise in frontier areas.

  That sounds almost as anti-social as when the Soviet union voided all
international agreements (including the Geneva convention) or when the Mullas
in Iran felt they were above worldly stuff like diplomatic status.

  If the US did something like that, and stepped somebody on the toes (like
drowning out others transmissions, crowding out their satelites, and start
drilling for oil in the Norwegian zone (or Russian zone, or Argentinean zone),
I'd expect an international conflict on the level of at least trade war.

>[e-mail]        Tuesday, November third  ##  Libertarian  $$  vote

-bertil-
--
"It can be shown that for any nutty theory, beyond-the-fringe political view or
 strange religion there exists a proponent on the Net. The proof is left as an
 exercise for your kill-file."
"This is the famous Hasan B Mutlu-trigger, insert it in your .sig file today!"

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

Date: 16 Sep 92 20:49:42 GMT
From: TS Kelso <[e-mail]>
Subject: Two-Line Orbital Element Set:  Space Shuttle
Newsgroups: sci.space

The most current orbital elements from the NORAD two-line element sets are
carried on the Celestial BBS, [phone], and are updated daily (when
possible).  Documentation and tracking software are also available on this
system.  As a service to the satellite user community, the most current
elements for the current shuttle mission are provided below.  The Celestial
BBS may be accessed 24 hours/day at 300, 1200, 2400, 4800, or 9600 bps using
8 data bits, 1 stop bit, no parity.

Element sets (also updated daily), shuttle elements, and some documentation
and software are also available via anonymous ftp from archive.afit.af.mil
(129.92.1.66) in the directory pub/space.

STS 47
1 22120U 92 61  A 92259.91666666  .00076267  00000-0  25599-3 0   136
2 22120  57.0011  92.2892 0008799 291.0911 351.7450 15.89483576   529
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]                    Air Force Institute of Technology

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

End of Space Digest Volume 15 : Issue 213
------------------------------