Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v12_4/v12_485.txt

Internet Message Format | 1991-06-28 | 15KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/wb9c0V200VcJAkfk5K>;
          Thu, 25 Oct 1990 02:03:13 -0400 (EDT)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Thu, 25 Oct 1990 02:02:39 -0400 (EDT)
Subject: SPACE Digest V12 #485

SPACE Digest                                     Volume 12 : Issue 485

Today's Topics:
              Re: Launch cost per pound
             NAVY WITHOLDING EVIDENCE!!!
             Re: Theories needed on life
     Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)
                  Re: Pluto

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 23 Oct 90 20:40:11 GMT
From: hub.ucsb.edu!ucsbuxa![e-mail]  (Charles Frank Radley)
Subject: Re: Launch cost per pound

In article <[e-mail]> [e-mail] (David Anderman) writes:

>Actually, it might be cheaper to launch the Soviet rockets from the Cape
>(Canaveral) than Baikonur. Yes, workers here get paid more $, but the
>decrease in Delta V needed to get into orbit from Florida may make up
>the difference.....


>--
>David Anderman
>Internet: [e-mail]

It depends on the destination orbit.    For LEO, KSC is a superior site
because you can get from 28 deg to about 55 deg inclination.
From Baikonur they are limited to about 45 deg or greater inc.
But for Geosynchronour orbit, the plane change penalty is
relatively small, and outweighs any advantage of relocating
infrastructure to a different location.
:

>--------------------------------------------------------------------------

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

Date: 23 Oct 90 03:09:00 GMT
From: sgi!cdp![e-mail]
Subject: NAVY WITHOLDING EVIDENCE!!!



                         "UFO CENTRAL"
                        The Forbidden City
                            Area# 51

Produced by: Audrey Lauin
Reported by: Bill McGowen both of "Current Affair(10/11/90)8:00p.m.

Just afew miles from Las Vegas, there exists a "TOP SECRET" installation
called area# 51. This area is run by the U.S.Dept of Energy. Jaime Shandera
calls the top secret area within area# 51: "DREAMLAND"! A ring of mountains
surrounded by another ring of mountains.

An Electro Physicist named: Bob Lazar known for his work with Los Alamos
Meson Physics facility along with his many years with NASA has come forward
with information on the Navy's (9) captured disks(U,(UFOs). He was employed
and/or assigned to analize one of these crafts. He Says: 'these things
were not built by human hands as the technology is far beyond anything we
have; Just the reactor & power source alone put out a tremendous amount
of power! It was very obvious what was in the hanger---a typical flying
saucer! The fuel that the reactor uses is a SUPER heavy element, something
described as 115 on the periotic charts! It's a material that we cannot
create here on earth, nevertheless find naturally in nature. It just doesn't
exist!!!

Ten years ago this was the place where the top secret stealth bomber &
fighters were designed and flight tested, along with countless under-
ground nuclear bomb testing. Many researchers state that if the military
wanted to hide an alien space craft; this would be the place to hide it!!!

Mr.Lazar brought friends to the parimeter of the base on the evening of
March 29th,1989 @ 8:29p.m. & photographed the first "TEST FLIGHT" of
said alien space craft by our own military scientists!!!

Soon thereafter Mr.Lazar became a modern man without a country!
His birth certificate, records of government jobs, coworkers,
everything vanished.....................As if I was never born!!!

Doesn't this piss you off to realize that our own government(CRIMINALS),
are withholding evidence from the American public on things such as
the discovery of life outside our own universe and the hardware thereof????

Something should be done to force these criminals to release these glorious
things that belongs to the American people; NOT THE GOD DAMBED NAVY!!!!

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

Date: 22 Oct 90 13:05:48 GMT
From: uceng!minerva![e-mail]  (Daniel Mocsny)
Subject: Re: Theories needed on life

In article <[e-mail]> [e-mail] (Kevin D. Quitt) writes:
>In article <[e-mail]> [e-mail] (Michael McNeil) writes:
>>It's highly likely that humanoid life wouldn't exist even on a planet
>>just like the Earth -- if life were to independently evolve again.
>>There are just too many other possible pathways for it to follow.
>    Either that, or the humanoid form is like a chaotic attractor, and
>almost all evolutionary forms end up with it - which seems a whole lot
>more likely to me.  (Not that I feel it's all that wonderful, I just
>don't see anything wrong with it, and I doubt we're really all that
>special).

Precedent exists of distinct evolutionary lines converging on a
common form. E.g., compare the dolphin, the swordfish, and the
ichthyosaur. The laws of hydrodynamics and physiology guarantee
that medium-sized aquatic predators have to have a certain shape
if they are to succeed, regardless of whether they are mammal,
fish, or reptile. The hydrodynamic penalty for the wrong shape is
so large that significant variation is unlikely. (Although I see
no reason to rule out mammallian or reptillian analogs of something
like, say, the manta ray.)

Also consider the bat and the pterosaur.

But the human form is not especially adapted for maximum mechanical
performance in any environment that I know. Humans seem to succeed
because they are so adaptable, and this is mostly a function of
mobility, intelligence, communication, binocular vision, and manual
dexterity.

An extraterrestrial creature capable of science and civilization
would have to duplicate some of the capabilities of the human
(or substitute something equivalent). Mobility appears to be
essential for the development of intelligence (see "The Rovers",
by Hans Moravec, in "Robotics", ed. by Marvin Minsky, Omni Press,
1985). Successfully mobile creatures must have some method of
rapidly sensing their changing environment (vision, sonar), and
the brain development to match. Alternative senses that could
provide similar information about the environment may be possible,
but are somewhat hard to imagine. For example, olfactory and tactile
senses are very important to lower animals, but these do not seem as
generalizable as vision and hearing, so we would not expect them to
be as important to a creature capable of developing a human-like
culture.

The versatility of carbon chemistry seems to rule out life evolving
from anything else, and I doubt that we will be seeing a protein-based
radar set!

I would be surprised to see our humanoids depending on much other
than vision and hearing, the way humans do. Sonar appears to be
popular only in environments where vision doesn't work too well,
such as underwater (cetaceans) or in darkness (bats). Some good
evolutionary reason may exist for this, but I couldn't guess what
that might be. Higher vertebrates overwhelmingly use binocular vision
(although invertebrates have many other arrangements), and this may
represent some fundamental optimum. And the higher the vertebrate,
the greater the overlap between the visual fields of the eyes. This
may also be unavoidable, but who knows?

Manual dexterity would require something like the hand, with its
exquisite motor control and tactile feedback. Without this, technology
would be impossible. However, the humanoid's manipulator need not
resemble the hand exactly, beyond the need for opposable grippers.
Something like the elephant's trunk might do as well, although the
need for more than one of them seems fairly clear.

For communication, speech is hard to beat. Chemical communication
on the insect model is probably too specific to be generalizable
to an advanced culture. Visual communication on the animal model
(plumage display, etc.) has mostly to do with mate selection and would
not seem to generalize readily. Although one wonders about the possibility
of an intelligent chameleon-like creature with pixel-addressible
pigment cells developing a visual language by displaying symbols on
its skin! (Squids may have a rudimentary communication based on
pigmentation changes. This might conceivably replace speech in our
humanoids, given that vision is probably going to be necessary
anyway. However, acoustic signalling has many advantages for
coordinating group action in emergencies, since it does not rely
on line-of-sight or focused attention.)

Bipedal stance exists in humans probably as a side effect of the need
to free up the manipulators (hands), of which at least two must
exist, and having only four limbs to work with. Why four limbs, we
can't say, given that invertebrates do well with any number of limbs.
The number of limbs will probably be even, as this seems to be
preferred, unless we count prehensile tails.

So our humanoid could wind up looking like almost anything, except
that it would probably have at least two hand-like things, and probably
two forward-facing eyes. It would be mobile, but not especially good
at it compared to other creatures in its environment. It would
probably be unspecialized for combat, speed, digging, or any other
mechanical function, forcing it to rely on its wits and cooperation
with others of its kind.


--
Dan Mocsny                Snail:
Internet: [e-mail]    Dept. of Chemical Engng. M.L. 171
      [e-mail]        University of Cincinnati
513/751-6824 (home) 513/556-2007 (lab)    Cincinnati, Ohio 45221-0171

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

Date: 23 Oct 90 02:07:17 GMT
From: zephyr.ens.tek.com!tektronix!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>the biggest gap is between Madrid and Canberra.  Maybe they could
>>put one is, say, India? ...

>
>Why bother? In principle two would suffice, if you put them precisely
>180 degrees apart and didn't mind working right down on the horizon
>just before switchover.  In practice you don't want to work at that
>low an angle, and the choice of positions is limited, but three is
>quite adequate to give complete coverage for anything not enormously
>out of the ecliptic.  If you just want to add more antennas, it is
>almost certainly more cost-effective to add them at existing sites and
>make use of existing support facilities.

There are scheduling advantages to putting new antennae in, say, India
and Brazil instead of adding to exisiting sites.  The DSN is typically
scheduled in several-hour long blocks; it usually takes 15 minutes to two
hours to reconfigure an antenna and associated equipment for a different
mission.  There are many constraints due to round-trip light time and
mission requirements.  For example, Magellan in "continuous coverage 70m"
mode requires Magellan always be covered by at least one of the large
antennae, due to Magellan's relatively small on-board data storage.
(Magellan can't store its data long enough to skip an antenna).

I can't do it over news, but draw a circle representing the earth
with tangents through points 90, 210, and 360 on the circle
representing the three DSN sites.  (In reality horizon constrains to
around 150 degrees, not 180 tangent, depending on horizon, and the earth
is 3D, but this model will illustrate the point).  We get 6 regions
of space, 3 viewable from 2 sites, and 3 viewable from 1.  The regions
viewable from only 1 site are a significant fraction of deep space.  Now try
4 sites, evenly spaced at 90 degrees.  The regions covered by only 1
antenna are now merely earth-diameter cylinders, an infinitesimile fraction
of deep space.

With the 4 evenly spaced sites (or, in reality, 5 oddly spaced sites,
with one in India and one in Brazil) we always have 2 dishes to
choose from instead of 1.  In the Magellan example, currently there
are several hours per day per site that an (often specific kind of) antenna
*must* be pointed at Magellan.  With 5 sites this requirement is eliminated,
and we can always cover another important mission or emergency at any site
without losing a chunk of Venus.

This flexibility may or may not be enough to offset the added costs
(economic and political, as was pointed out) of building at new sites.
The most flexible arrangement of all would be a nice large antenna in
GEO.....

Nick Szabo
*** NEW ADDRESS ***
uunet!sequent.com!szabo
These are my opinions, not Sequent's.

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

Date: 24 Oct 90 15:47:25 GMT
From: munnari.oz.au!uhccux![e-mail]  (David Tholen)
Subject: Re: Pluto

In article <[e-mail]>, [e-mail] (Ron Baalke) writes:

> I did a little further research on this.  In the 1990 Astronomical Almanac,
> page F2, it lists Pluto  of having a 94 degree orbital inclination to the
> planetary equator of 1950.  In the book called "Planets Beyond, Discovering
> the Outer Solar System",  1990 edition, page 296, Pluto is also listed as
> having a 94.0 degree inclination of equator to orbit.  However, in the
> "The New Solar System", 3rd edition, page 291, Charon is listed as having
> an orbital inclination of 98.8 degrees.

The Astronomical Almanac stills uses my 1985 orbit, which is quite out of
date (doesn't include ANY of the new mutual event data).  The New Solar
System is more recent, but still out of date.  I'll be introducing the
new 99.0 degrees inclination in a few hours at the Division for Planetary
Sciences meeting.  Planets Beyonds probably took their figure from the
Astronomical Almanac, which is usually a reliable source, but they don't
update their data every year.

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

End of SPACE Digest V12 #485
*******************