Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_3/V11_389.TXT

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Subject: SPACE Digest V11 #389

SPACE Digest                                     Volume 11 : Issue 389

Today's Topics:
                Re: Apollo 12
                Re: Apollo 12
       this is a test... disregard if you receive this
             Re: Manned Mission To Venus
            Re: Niven's Inertialess Drive
       Re: Hubble Space Telescope Update - 05/09/90 (Forwarded)
              Re: launch windows
               Re: why there are no ETs
             Re: Terraforming Venus/Mars
    Re: Terraforming Venus (was: Manned mission to Venus)
    Re: Terraforming Venus (was: Manned mission to Venus)
    Re: Terraforming Venus (was: Manned mission to Venus)
                  Space List
----------------------------------------------------------------------

Date: 10 May 90 20:00:18 GMT
From: cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!prls!philabs!briar![e-mail]  (Robert Casey)
Subject: Re: Apollo 12

In article <[e-mail]> [e-mail] (David Smith) writes:
>Gregory Bond asked why launch windows happened only a few days a month.
>They wanted to land with a low sun angle, to bring out the relief at the
>landing site.  If they waited too long, the sun would be too high.  I
>presume they didn't want to land near sunset, because if landing or lunar
>takeoff were delayed, they would end up in the dark.

If they were a few days late launching, why not land at another
selected spot on the Moon where the Sun angle would be good at that
time?  I'm assuming that the site selection committee had selected more
than one site.  And in the early flights, one easy spot is as good as
another, if your main objective is to get the flight in before the end
of the decade.

Maybe the problem would be the lack of computing capability to get the later
flight planned out in full?

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A notice attached to a piece of equipment made in Japan:
"It put on the vinyl sheet on the surface of upper & lower panel for the
protection  Please use after tear off vinyl sheet when using."
--ShibaSoku Co., Ltd.

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

Date: 11 May 90 16:21:09 GMT
From: hplabsb![e-mail]  (David Smith)
Subject: Re: Apollo 12

In article <[e-mail]> [e-mail] (Robert Casey) writes:
>If they were a few days late launching, why not land at another
>selected spot on the Moon where the Sun angle would be good at that
>time?  I'm assuming that the site selection committee had selected more
>than one site.  And in the early flights, one easy spot is as good as
>another, if your main objective is to get the flight in before the end
>of the decade.

The crew's preparation was for one landing site.  Once the LM pitched over
so they could see the surface, they started navigating (or checking
navigation) by landmarks they had drilled into memory.  During the
moonwalks and drives, they had a specific well-learned itinerary, which in
the case of Apollo 12 included visiting a Surveyor.
--
    David R. Smith, HP Labs
    [e-mail]
    [phone]

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

Date: Fri, 11 May 90 18:41 CDT
From: Buckaroo Bonzai and the Team of Baker Street Irregulars
 <[e-mail]>
Subject: this is a test... disregard if you receive this
To: [e-mail], [e-mail], [e-mail],
        [e-mail], [e-mail],
        [e-mail], [e-mail],
        [e-mail], [e-mail],
        [e-mail]
X-Envelope-To: [e-mail]
X-Vms-Cc: ELEE6WK

this is a test.. please disregard if you get this... my mail router here
at the university of houston has died a death or two.
william sanders, a subscriber to this list

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

Date: Fri, 11 May 90 17:19:57 CDT
From: [e-mail]
Subject: Re: Manned Mission To Venus

> clyde.concordia.ca!mcgill-vision!quiche!calvin![e-mail]  (Mark SOKOLOWSKI)

> When I was talking "cultural", I was talking about the soil composition,
> landscape features, and gravity, which would make life on Venus so much
> similar to those of Earth's.

Hmmm, not sure how soil composition, landscape features and gravity
became *cultural*, but we'll let that pass.  It's quite simply plain
silly to think that "life on Venus [would be] so much similar to
those of Earth's".

> [Much ranting about "challenge", "adventure", "excitement" and
> such deleted.]

I've got an idea for Mr. Sokolovski.  Rather than going to Venus,
why not launch a pair of missions; one to land on the Sun and one to
land on Jupiter.  Now *there* would be "challenge", "adventure", and
"excitement"!  It also wouldn't be *that* much more difficult than
staying on Venus.

I fail to understand how anyone who is 20 could still be so grossly
misinformed about what is reasonable/possible within the realm of
the current technology.

==============================================================================
| Fred McCall  ([e-mail]) | "Insisting on perfect safety is for  |
| Advanced Systems Division           |  people who don't have the balls to  |
| Defense Systems & Electronics Group |  live in the real world."            |
| Texas Instruments, Inc.             |                     -- Mary Shafer   |
+-------------------------------------+--------------------------------------+
|  I speak for me.  I don't speak for others, and they don't speak for me.   |
==============================================================================

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

Date: Fri, 11 May 90 17:16:25 CDT
From: [e-mail]
Subject: Re: Niven's Inertialess Drive

I find myself under the impression that the 'inertialess drive' was
invented by the Kzinti, and that it was acquired at the end of the
First Man-Kzin War.

This is why the Kzinti were so surprised upon their invasion of the
Solar System and the root of the Kzinti Lesson about fusion drives.

[I have a copy of _The Man-Kzin Wars_ at home somewhere.  Maybe I
need to dig it up and see if this is mentioned.]

==============================================================================
| Fred McCall  ([e-mail]) | "Insisting on perfect safety is for  |
| Advanced Systems Division           |  people who don't have the balls to  |
| Defense Systems & Electronics Group |  live in the real world."            |
| Texas Instruments, Inc.             |                     -- Mary Shafer   |
+-------------------------------------+--------------------------------------+
|  I speak for me.  I don't speak for others, and they don't speak for me.   |
==============================================================================

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

Date: 11 May 90 06:47:39 GMT
From: usc!cs.utexas.edu!texbell!texsun!csccat![e-mail]  (Jack Hudler)
Subject: Re: Hubble Space Telescope Update - 05/09/90 (Forwarded)

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>"Hubble Space Telescope's First Picture Could Come Wednesday"
>
>Rosenthal says the picture would be of a 3-billion-year-old star
>field called Theta Carina, or "Ship's Keel," located in the
>southern sky and that the star cluster is 1,260 light years away
>and visible with the naked eye in Africa, South America and
>Australia.

I figures, tha %*&^%*s wouldn't image anything we can compare it to up here!
--
Jack         Computer Support Corportion        Dallas,Texas
Hudler        UUCP: {texsun,texbell}!csccat!jack

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

Date: 11 May 90 15:51:16 GMT
From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: launch windows

In article <[e-mail]> [e-mail] (Patty Winter) writes:
>What I've been trying to figure out (and some of my friends say the
>same) is why there was a "launch" (release) window for HST....

As I recall, the biggest constraint was that the deployment of the solar
arrays finish at "sunrise" (passage out of the Earth's shadow) to give
maximum opportunity for battery charging at the first possible moment.
The power umbilical from the orbiter had to be disconnected before the
start of deployment, so HST was on batteries thereafter, and they were
*very* concerned about making sure that it not drain them dry.
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 11 May 90 00:45:15 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: why there are no ETs

In article <[e-mail]> [e-mail] (Brian Yamauchi) writes:
>[me]
>>I still like my explanation.  When you achieve interstellar travel
>>or communication, someone comes along and kills you.
>
>Which also has the same flaw mentioned above -- it assumes the killers
>are able to succeed in all cases.  I can believe in berserkers, but
>not in omniscient, omnipotent berserkers.

Aw come on.

If you know how to move asteroids around you can take out Earth's higher
civilization RIGHT NOW.  Splash a few of them and we're back to the Dark
Ages just like >that<.  If we're lucky.  And we won't claw our way up
to today's golden age in 600 years like last time either, because Earth's
climate will SUCK and we already took all the easy minerals.  The survivors
will be SOL for millenia at best.

If the exterminators stick with the program a little longer,  I don't think
we need to worry about any survivors.  Maybe SETI should stand for Search
for Extra-Terrestrial Insects.

The nice part about my theory is that you only need ONE berserker race
to make it work.  The first ones to learn how to move around and do their
jobs, make everything else neat.

My second theory is that everyone figures out the first theory and clams
up out of paranoia.  :-)
--
War is like love; it always      \%\%\%   Tom Neff
finds a way. -- Bertold Brecht   %\%\%\   [e-mail]

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

Date: 11 May 90 17:27:30 GMT
From: mcsun!inesc!unl!unl![e-mail]  (Vitor Duarte & Sergio Duarte)
Subject: Re: Terraforming Venus/Mars


Two habitable planets for the price of one:
take the excedent CO2 from Venus to Mars...


--
---
 Sergio Duarte                     BITNET/Internet: [e-mail]
 +---------------------------------+           UUCP: [e-mail]
 |   Departamento de Informatica   +----------------------------------+
 |   F.C.T. / Universidade Nova de Lisboa                             |
 +--------------------------------------------------------------------+

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

Date: 11 May 90 09:04:24 GMT
From: zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uluru5![e-mail]  (Daniel Ake CAROSONE)
Subject: Re: Terraforming Venus (was: Manned mission to Venus)

In article <[e-mail]>, [e-mail] (Edward Joseph Bennett) writes:
>> [using ice from Saturn's rings is BAD IDEA]
> Good point. We can use rings from Jupiter or Neptune or some set of
> rings that is not as spectacular. Would we have to use enough of the
> rings to make a noticable difference anyhow?

As I understand it, such a system is drectly under the influence of chaos.

ie make a small change in initial conditons, and the resulting system n
time units later is vastly different to that if no change had been made.
Admittedly this is in reference to the positions of individual particles
within the rings, but I think that any amount of ice removed that would
help at all on venus would effect drastic change to the rings.

Note to future^n readers: Please Don't!

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

Date: 11 May 90 18:31:24 GMT
From: [e-mail]  (Paul Hager)
Subject: Re: Terraforming Venus (was: Manned mission to Venus)

[e-mail] (Brian or James) writes:


] I think using Saturn's rings as H2O fodder for terraforming
]Venus is a Bad Idea. There are other sources of ice in the
]Solar System, and destroying a beautiful ring sytem unecessarily
]seems wrong. Kind of similar logic to national parks or
]historic buildings. The Rings have a value where they are.
]                        JDN

I think the poster raises an interesting problem -- aesthetics
versus utilities.  We see this polarity reflected in ideologies
and politics today and as we push out into space there is no
reason to assume that we won't carry our culture and attitudes
with us.

Personally, I'd dismantle the rings in a New York minute if I
could terraform a planet in the process.  This puts me at the
opposite pole.  If the people who move out are no-nonsense,
utilitarian types like me then I venture to say that political
suasion will not prevail against the advantages the colonists
would have with access (the laws of physics being what they
are).  However, I'd expect a few poets and aesthetes would
be along on the trip out -- enough to curb the worst excesses
of people like me.

In the end I'm sure some compromise will be worked out -- it
usually is.  Politics in the 22nd Century promises to be a
real gas.
--
paul hager        [e-mail]

"I would give the Devil benefit of the law for my own safety's sake."
                       --from _A_Man_for_All_Seasons_ by Robert Bolt

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

Date: 11 May 90 20:56:37 GMT
From: thorin!homer![e-mail]  (Jonathan Leech)
Subject: Re: Terraforming Venus (was: Manned mission to Venus)

In article <[e-mail]> [e-mail] (Paul Hager) writes:
>Personally, I'd dismantle the rings in a New York minute if I
>could terraform a planet in the process.

    Why bother, when perfectly good ice moons like Enceladus are
available (as Dyson originally proposed - nobody seems to be giving
credit where due).
--
    Jon Leech ([e-mail])    __@/
    ``The tuba recital is one of the most memorable experiences of
      music school.''
    - Seen on a bulletin board in the UNC Music School

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

Date: Fri, 11 May 90 13:05:37 PDT
From: [e-mail]
X-Vmsmail-To: UTADNX::UTSPAN::AMES::"[e-mail]"
Subject: Space List

Space List: What every Space Enthusiast Should Know

A List of Numbers and Equations Relevant to Space Exploration
  courtesy Dale M. Greer

Numbers
   9.8 m/s^2       (  10) -- Acceleration at surface of Earth (one g)
  7726 m/s         (8000) -- Earth orbital velocity at 300 km altitude
  3075 m/s         (3000) -- Earth orbital velocity at 35786 km (geosync)
  6371 km          (6400) -- Mean radius of Earth (Re)
  6378 km          (6400) -- Equatorial radius of Earth (Re)
  1738 km          (1700) -- Mean radius of Moon (Rm)
  5.974e24 kg      (6e24) -- Mass of Earth (Me)
  7.348e22 kg      (7e22) -- Mass of Moon (Mm)
  1.989e30 kg      (2e30) -- Mass of Sun (Ms)
  3.986e14 m^3/s^2 (4e14) -- Gravitational constant times mass of Earth
  4.903e12 m^3/s^2 (5e12) -- Gravitational constant times mass of Moon
  1.327e20 m^3/s^2 (13e19) - Gravitational constant times mass of Sun
  384401 km        ( 4e5) -- Mean Earth-Moon distance
  1.496e11 m       (15e10) - Mean Earth-Sun distance (Astronomical Unit)
  1371 W/m^2       (1400) -- Mean solar constant at 1 AU

Conversions
  1.61   km / mi
  0.0254 m / in
  3.28   ft / m
  0.3048 m / ft
  1.467  fps / mph  (or 88 fps = 60 mph, exactly)
  0.447  m/s / mph
  2.2    lb / kg  (2.2 pounds-mass, that is)

Comparisons
  1 MJ = 0.28 kW hr

Equations
  Where d is distance, v is velocity, a is acceleration, t is time.

  For constant acceleration
    d = d0 + vt + .5at^2
    v = v0 + at
    v^2 = 2ad

  General Gravity
    f = G m1 m2 / r^2
    a = v^2 / r
    g = G Me / r^2

  For circular Keplerian orbits, where u is gravitational constant, a is
    semimajor axis of orbit, P is period.
      v^2 = u/a
      P = 2pi/(Sqrt(u/a^3))

  Miscellaneous
      f = ma -- Force is mass times acceleration
      w = fd -- Work (energy) is force times distance

  Atmospheric density varies as exp(-mgz/kT) where z is altitude, m is
  molecular weight in kg of air, g is acceleration of gravity, T is
  temperature, k is Bolztmann's constant.  Up to 100 km,
    d = d0*exp(-z*1.42e-4)
  where d is density, d0 is density at 0km, is approximately true, so
    d@12km (13000 m -- 40000 ft) = d0*.18
    d@9 km ( 9800 m -- 30000 ft) = d0*.27
    d@6 km ( 6500 m -- 20000 ft) = d0*.43
    d@3 km ( 3300 m -- 10000 ft) = d0*.65

Selected Planetary Data

        Semimajor Axis   Sidereal Synodic Incl.to Grav.Cst.       Mass
                           Period  Period Eclipt. GM (10^12
          (AU)   (Mm)     (Tr.Y.)  (Days)   (deg)  m^3/s^2)    10^24kg
Mercury  0.3871   57.9    0.24085  115.88  7.0042     22.03    0.33022
Venus    0.7233  108.2    0.61521  583.92  3.3944    324.86    4.8690
Earth    1.0000  149.6    1.00004                    403.50    6.0477
Mars     1.5237  227.9    1.88089  779.94  1.8500     42.83    0.64191
Jupiter  5.2028  778.3   11.86223  398.88  1.3047 126712.0  1899.2
Saturn   9.5388 1427.0   29.4577   378.09  2.4894  37934.0   568.56
Uranus  19.1819 2869.6   84.0139   369.66  0.7730   5803.2    86.978
Neptune 30.0578 4496.6  164.793    367.49  1.7727   6871.3   102.99
Pluto   39.44   5900    247.7      366.73 17.17       40       0.7

The Moon         384.4   27.3217days                   4.90    0.073483

(Suggestions?  Favorite numbers, equations?  Some rocketry info would be nice.)

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

End of SPACE Digest V11 #389
*******************