Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V09_2/V9_256.TXT

Internet Message Format | 1991-07-08 | 19KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from holmes.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/4Y0xcny00UkZ0Y705N>;
          Thu, 23 Feb 89 05:17:23 -0500 (EST)
Message-ID: <[e-mail]>
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Thu, 23 Feb 89 05:17:14 -0500 (EST)
Subject: SPACE Digest V9 #256

SPACE Digest                                      Volume 9 : Issue 256

Today's Topics:
              Re: 1992 moon base
              Re: 1992 moon base
               Voyager Bulletin
         Re: French small space shuttle: A go ahead !
              Re: 1992 moon base
         Congressional Members and Addresses
                Voyager Images
               Synthetic Aperture Radar
----------------------------------------------------------------------

Date: 19 Feb 89 01:09:31 GMT
From: ndcheg!uceng![e-mail]  (daniel mocsny)
Subject: Re: 1992 moon base

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
> In article <[e-mail]> [e-mail] (daniel mocsny) writes:
> >... We can't just dump people in cans and expect
> >them to huddle heroically while we try to build a reliable launcher to
> >get them back home. We have to give them the tools to not simply
> >survive on the moon, but to take it.
>
> "We can't just dump people in covered wagons and expect them to huddle
> heroically while we try to build a railroad to bring them back."

I see similarities in the analogy, but important differences. When
people know they aren't going back, you can count on a maximum effort,
and you might be pleasantly surprised. But comparing the American West
to the Moon?

Before the White Man "developed" the West, it already boasted a
thriving ecosystem supporting a few million people. Game was so
insanely plentiful that if you were hungry you had only to step out of
the wagon and open fire. Dealing with hostile natives (and they
generally were not initially hostile) was usually a fairly simple
matter of introducing firewater and European diseases. Weather was a
problem, but to get a nice fur coat, you only needed a large-bore
rifle and a steady aim. Building materials were plentiful if you could
swing an axe, the soil was fertile, the land was free, draft animals
were simple to raise...

On the moon you have to make everything out of rocks. I need to see
those ISS studies (I couldn't find them at the University of
Cincinnati libraries). Any references/pointers, anyone?

Dan Mocsny
[e-mail]

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

Date: 15 Feb 89 22:15:10 GMT
From: [e-mail]  (Jordan Kare)
Subject: Re: 1992 moon base

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>>Wonderful, Henry.  Lunar colonies (= a handful of people huddled
>>underground) are feasible if you don't have to pay for little things
>>like labor, materials or launchers...
>
>Not quite what I said, which was that a startup lunar colony was very cheap,
>and looked feasible *BY 1992*, if most of the big-ticket items were donated.
>(As for "a handful of people huddled underground", most of the early colonies
>in North America started with not much more, especially after the first
>winter.)

From "Toward a Permanent Lunar Settlement in the Coming Decade:
The Columbus Project" by R. Hyde, M.Y. Ishikawa, and L. Wood:

    PURPOSEFUL EXISTENCE.  The essence of a human settlement is not
    just to permit people to survive, but to thrive.  The lunar
    settlement must therefore provide for purposeful activity by
    the settlers, not just huddling in a shelter waiting for ... the
    time to return to Earth to finally arrive.  Exploration and
    exploitation of the nearby lunar environment, primarily to extend and
    enrich the settlement, is thus provided for, by both tele- and
    directly-operated lunar rover-type vehicles... and by lunar soil
    processing modules.

>
>>By the way, how many shuttle
>>flights per year would be needed for support of this thing?
>
>This was a *colony*, not a base, meaning no crew rotation and the intent
>to be self-sufficient in basic materials essentially at once.
...
>--
>The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
>our nine months are up.        | uunet!attcan!utzoo!henry [e-mail]

The colony was to be self-sustaining for two years, and had its own
return capability, so no further flights were required if the colony
were to shut down.  The total cost was to be $500 million, including
6 shuttle flights "having a current NASA-assigned value of about
$240 million" (remember, NASA in those days was pricing Shuttle flights
at $40 million each.  sigh.)  To quote further,

    To this cost of the hardware base must be added that
    of the human endeavor to carry out the Project.  One
    peculiarly American way for the necessary effort to be
    provided would be on a completely volunteer basis from
    all walks of American life, particularly the technical
    professional ones.  The self-selected portion of what we
    confidently believe is a huge talent pool committed to an
    American manned presence in space could clearly carry out
    the Project on the required time scales, and with magnitudes
    of ... personal contribution consonant with volunteer effort
    by professionals holding more-or-less unrelated full time jobs.

One can argue that the Columbus Project was overly optimistic,
but the authors of the proposal _had_ done their homework.

    Jordin Kare

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

Date: Sun, 19 Feb 89 10:33:50 PDT
From: Peter Scott <[e-mail]>
Subject: Voyager Bulletin
X-Vms-Mail-To: EXOS%"[e-mail]"

The following is extracted without permission from the _Voyager Bulletin_,
Mission Status Report #84, January 30, 1989, published by NASA at JPL.
(Comments in [] are mine.)

Update:
-------
    Voyager 2 is 4.36 billion kilometers (2.71 billion miles) from Earth.
Neptune lies 298.95 million kilometers (185.76 million miles) and slightly
more than six months ahead.  With a velocity of about 18.9 kilometers per
second (42,380 miles per hour), Voyager 2 travels over a million miles a day.
[...]

Encounter Period Overview:
--------------------------

    The Neptune encounter period will officially begin on June 5, 1989,
81 days before Voyager 2's closest approach to Neptune.  The first 62 days
are called the "observatory" phase, and will consist of continuous observations
of the Neptunian system and numerous pre-encounter calibrations (checkouts)
of Voyager 2's instruments.  Science observations will include repeated scans
across the entire Neptunian system with the ultraviolet spectrometer to
look for neutral hydrogen and excited ions.  The imaging cameras will monitor
long-term atmospheric motion on the planet and search for ring arcs and
satellites.  A trajectory correction maneuver is scheduled for August 1.

    On August 6, 19 days before closest approach, the "far encounter"
phase will begin.  By then, at least two narrow-angle camera frames will
be required to capture the entire planet and the ring-arc region.  Satellite
observations, detailed ring observations, and infrared observations of
Neptune will begin.
[...]

    The "near encounter" period, from August 24 to August 29, will contain
all of the highest value Neptune science, including a distant look at tiny
Nereid, a close swing over Neptune's north pole, and a close look at Triton,
as well as characterization of Neptune's magnetic field and searches for
possible ring arcs and other satellites.

    Voyager 2 will pass about 4,850 kilometers (3,000 miles) above the
cloudtops of Neptune at about 76 degrees north latitude.  This will be Voyager
2's closest approach to any object in the Solar System since it left Earth
nearly 12 years ago.

    Voyager 2's aimpoint at Neptune has been carefully chosen to bend
the flight path sharply below the equator again, where Voyager 2 will intercept
Neptune's large moon Triton at a distance of about 40,000 kilometers (25,000
miles) five hours after the spacecraft's closest approach to Neptune.
[...]

New News about the Neptunian System:
------------------------------------

    The imminent encounter with Neptune has sparked increased Earth-based
observations of Neptune's system, and some of the information is summarized
below.

Neptune:    Using the Infrared Telescope Facility (IRTF) at Mauna Kea,
    Dr. Heidi Hammel of JPL has detected discrete cloud features moving
across the disk of Neptune as the planet rotates.  These features are clearly
visible at 6190 Angstroms, the same wavelength as the methane-band filter
on Voyager's wide-angle camera.  As Voyager 2 gets closer to Neptune, these
features should become apparent in Voyager images.  Dr. Hammel also reports
that clouds at 38 degrees south latitude have a roation period of 17 hours,
while at 30 degrees south latitude the rotation period is 17.7 hours.
In addition, she reports a deep haze (down to an atmospheric pressure of
about 100 millibars) at the south pole, and a higher haze (down to about
50 millibars) at the north pole and in the northern hemisphere.
    Spectrophotometry observations indicate that Neptune may have a
three-layer cloud structure of icy hydrocarbons, a thin methane haze, and
a hydrogen sulfide cloud [thereby qualifying it as the most obnoxious-smelling
planet in the Solar System].
[...]

Triton:        Estimates of Triton's size are shrinking as some researchers
    now believe that the largest diameter that Triton could have is about
4,000 km (2,500 mi).
    Judging from light reflected by Triton, the satellite's temperature
may be about 52 K for a diameter of 3760 +/- 780 km (2340 +/- 480 mi).
[...]

Rings?        And finally, the question of Neptunian rings remains open.
    Out of 110 observed occultations of stars by Neptune, only 8
occultations produced effects that could be attributed to rings or ring
arcs near Neptune.  Small satellites shepherding ring particles at Neptune
could be as small as 10 km (6 mi) in diameter at distances of a few hundred
kilometers.  And, going far out on a limb, simulations show that polar rings
around Neptune would be stable [sheesh!].
[...]

Peter Scott ([e-mail])

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

Date: 20 Feb 89 18:53:36 GMT
From: mcvax!kth!osiris!sics![e-mail]  (Bruno Poterie)
Subject: Re: French small space shuttle: A go ahead !

In article <[e-mail]> [e-mail] (Jean-Marc Debaud) writes:
>   [... news about Hermes]
>   *Beware ! Europe (beside England) is waking up !*

You should care about your titles: Hermes is a *European* project, backed
up by the ESA. Your national pride, although comprehensible, gives a strange
idea of Europe to the locals on your side of the Atlantic:
    France first
    Great Britain never
    Germany sometimes
Believe me - a *lot of* subjects of H.G.M. are pro-Europe, including most
of their companies. It is actually Tatcher and Co who give the impression
that UK wants to remain out of the game. So _please_ do not confuse the UK
as a whole with the attitude of the British government.
[Personal note: Ne prend surtout pas ca pour un ordre, simplement je pense
qu'une attitude plus positive envers nos voisins d'outre-Manche avancera
davantage le schmilblick tant spatial qu'europe'en. Il y a d'ailleurs en
ce moment sur ce sujet une discussion tres inte'ressante dans eunet.politics,
dommage que tu ne puisses pas la suivre.]

And *for once* i may share some of Tatcher's fears: The Hermes project is
more the result of national/european pride and political motives than the
outcome of a real need. It will be dependant on a heavy and expensive booster,
and will be redundant with the American and Soviet shuttles. In order to
use it with reasonnable costs, we would need as well a sort of vehicle to put
it outside the Earth' attraction, at least high enough outside the atmosphere
(like a wind-glider is put in position by a small plane). But this project is
not going to be implemented abny time soon. So... It is time we stop spending
too much money on expensive projects, when those costs could be shared between
all (and i mean, all space-faring entities). Military/civil control would be
the major problem i believe, but there should be a way to work that out.

*Beware* is  therefore a ill-choosen word. Why not try this line:

    *Hello* America & Russia, Europe is there and ready to cooperate!

-- Bruno Poterie, IM, Kista, Suede   email: [e-mail]

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

Date: 19 Feb 89 20:43:24 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: 1992 moon base

One additional problem with the shuttle (vs. the Saturn V) is that a
lunar vehicle launched by the shuttle must use solid or storable
propellant rockets to leave earth orbit, rather than oxygen/hydrogen,
unless you are proposing to refuel in orbit with propellants launched
by something other than the shuttle.

If a shuttle can carry 27 tons and we use storable propellants with an
Isp of 300 to inject to and land on the moon, then six shuttle flights
lets us land about 21 tons on the moon (including the dry mass of the
landing vehicle).  Question: what was the mass and payload capacity of
the LEM?

Henry argued for the lunar colony not needing to be totally
independent by asking (rhetorically) what communities on Earth are
independent.  I do not think the comparison is fair, because
transportation costs to any community on Earth, even in Antarctica,
are far lower (by orders of magnitude) than the cost to the moon.
Therefore, we'd expect an "Earth colony" to be much more dependent
on imports than an economically viable lunar colony.

I noted with interest that the quotes from the document describing the
moon base mentioned teleoperated rovers.  This is a wonderful idea.  I
assume the teleoperation is from Earth.  If so, isn't their use
independent of whether a manned base is set up?

    Paul F. Dietz
    [e-mail]

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

Date: 20 Feb 89 00:06:30 GMT
From: deimos.cis.ksu.edu!uxc!tank!nucsrl!accuvax.nwu.edu![e-mail]  (Rob Lentz)
Subject: Congressional Members and Addresses

Hello,
    Since we have all these wonderful ideas and opinions about what
should (and what is going to) be done with/in the space program I was
wondering if there was anybody who could post the new congressional
members of the various committees (and just plain influential positions)
that deal with space/science.  This would be especially helpful with Quayle's
report coming up and all the dire consequences people are forecasting.
Or has the list not changed at all since last year?
    Thank you.

                    Robert Lentz
                  Internet: [e-mail]
                Bitnet: lentz@nuacc
                  UUCP: {gargoyle,chinet}!nucsrl!accuvax!lentz
------------------------------------------------------------------------------
"How can you be a man, til you see beyond the life you live?"
            -Boston, "What Does It Take To Be a Man?" _Third Stage_

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

Date: 20 Feb 89 19:36:03 GMT
From: romeo![e-mail]  (Bob Currier - DCAC Network Comm. Specialist)
Subject: Voyager Images



Does anyone know if the Voyager images are available to the public?
If so, can they be obtained in machine-readable format, i.e. 9 track
tape, or better yet, by anonymous FTP?  For that matter, are there
*ANY* images available free of charge, or for a modest fee that can be
had for experimentation with image processing?

We want to use our new NeXt box to play with the images...

Bob



|============================================================================|
| La prima parola della guerra e pronunciata                                 |
| dal cannone ma l'ultima e sempre detta dal pane.                           |
|                                                                            |
| Robert D. Currier                                                          |
| Duke University                                  [e-mail] |
| Department of Network Communications                                       |
|============================================================================|

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

Date: 21 Feb 89 01:00:05 GMT
From: Portia!hanauma.stanford.edu![e-mail]  (Joe Dellinger)
Subject: Synthetic Aperture Radar


    I attended a seminar here recently about the devastating Sept, 1985
earthquake in Mexico (the one that showed why it is not a good idea to
have highly populated flimsy buildings on top of jello).

    In order to predict how often you can expect such an earthquake,
it is useful to know how much the ground actually statically moves during
one. In California, for example, they do "we expect 5cm / 1 year movement
on the San Andreas, the 1906 earthquake moved 21 feet, so expect an
Earthquake like that every 120 years or so".

    Unfortunately, they lamented at the seminar that in Mexico there
HAS NEVER BEEN A GEODETIC SURVEY! (For some reason the English and all
English-influenced cultures are big on drawing straight lines on the
ground, while Spanish-influenced cultures are not.) So although they
suspect there was a large static ground motion, they really don't know
how much there was.

    The question is, is there some way to CHEAPLY measure such
ground motions (on the order of a meter or two) from space? We had
a professor here a year ago (Fabio Rocca from Italy) who used Stolt
migration of SeaSat data from two passes over Death Valley to create
"interference fringes".  The result clearly showed elevation changes
of ~6cm in the very flat Death Valley floor. So it seems it should
be possible.

    I asked him about it, and he said if you wanted to be accurate
you'd probably need to lay out a grid of Radar corner reflectors. These
would be half-cubes of metal about ~1m on a side. Should be cheap.

    So, questions:
1) Would countries like Mexico be amenable? Would the DOD be amenable?
2) Is there going to be a SAR equivalent to LandSat anytime soon, that
   seismologists could use to measure relative displacements of their
   corner reflectors?
3) Who would be in charge of actually setting up such a thing? The USGS?
   NASA? A University?
4) Has it already been done anywhere? How did it work?

    Enquiring minds want to know...
\    /\    /\    /\/\/\/\/\/\/\.-.-.-.-.......___________
 \  /  \  /  \  /Dept of Geophysics, Stanford University \/\/\.-.-....___
  \/    \/    \/Joe Dellinger [e-mail] decvax!hanauma!joe\/\.-._

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

End of SPACE Digest V9 #256
*******************