Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_0/V15NO085.TXT

Internet Message Format | 1993-07-13 | 30KB

Date: Sat,  8 Aug 92 05:02:03
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #085
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat,  8 Aug 92       Volume 15 : Issue 085

Today's Topics:
                       Atlas and Soyuz (2 msgs)
                  Circle-like things on shuttle map
                           Fermi's Paradox
                            Galileo issues
             Giotto - First Results from Comet Encounter
    Iron, stars, and magnetic fields (was Re: Red-blooded ET's : )
                        Meteor Soaks Datona FL
                     More second-hand info on TSS
                   Origin of Life article (3 msgs)
       Oxygen pills for EVA (was Re: Medicine for space walks)
               Question about shuttle launches (3 msgs)
                  Source of moon/apollo pix (2 msgs)
    Two questions about the shuttle tethered satellite experiment
                             Water-worlds
           Weird circle-like things on shuttle map (3 msgs)

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

Date: 7 Aug 92 04:17:32 GMT
From: [e-mail]
Subject: Atlas and Soyuz
Newsgroups: sci.space

Dennis Wingo writes in response to Allen Sherzer

>Also I have not seen your derated values for your Atlas payloads to
>270 nm. I think your numbers are for a 105 nm transfer orbit.
>Subtract a VERY significant amount for this.  Is that right Wales?

  In defense of Allen's numbers, he hasn't been quoting numbers for
the Atlas launcher...
   However, in general, you are right Dennis -- Atlas performance
has to be derated for launch to SSF nominal altitude, 220 nmi.  The
largest Atlas available, the Atlas IIAS, can put about 7500 kg into
220 nmi, 28.5 deg circular orbit using a direct insertion (including
a Centaur) from CCAFS. This vehicle has flown once.

   This is pretty close to the weight of a Soyuz TM... There are
sufficient uncertainties in the weight statements I've seen on the
Soyuz - the best I've seen show a Soyuz TM to mass 7070 kg at
liftoff, but I've seen others with masses up to 7100 kg.  However,
we still have to add any ASE for Soyuz/Atlas interface, a launch
escape tower, the mass of an androgynous docking adaptor (in place
of the existing Kurs automatic docking system, and any modifications
desired to extend Soyuz life beyond the current 180 days.  Not to
mention any other mods necessary to upgrade the unmanned Atlas to a
"man-rated configuration" - with increased mass TBD.
   In my opinion, those masses will probably put the total mass over
the Atlas 7500 kg capability.
    But it is close enough to be interesting.
 ------------------------------------------------------------------
 Wales Larrison                         Space Technology Investor

--- Maximus 2.00

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

Date: 7 Aug 92 12:50:34 GMT
From: [e-mail]
Subject: Atlas and Soyuz
Newsgroups: sci.space

Several points on the issue of using Atlas as a launch vehicle for Soyuz:

The nominal SSF orbit is somewhat higher than the nominal Atlas orbit cited
(220 nmi). However, the Centaur upper stage is very good at creating Delta V;
it is not so good at lifting realtively large payloads, such as a oyuz.Soiyuz

--- Maximus 2.00

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

Date: 7 Aug 92 19:46:20 GMT
From: John Eisenberg <[e-mail]>
Subject: Circle-like things on shuttle map
Newsgroups: sci.space

On NASA television, the globe that has the shuttle moving around
it has strange circle-like objects on it.  They appear to be
centered on possible tracking stations or emergency landing
areas.

Does anyone know what they are and why the are shaped as they are?

Thanks,
John

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

Date: Fri, 07 Aug 92 17:24:13 EDT
From: Tom <[e-mail]>
Subject: Fermi's Paradox

>The only argument against extraterrestrial life/intelligence that strikes
>*me* as being particularly telling is the Fermi Paradox:  if they're out
>there, why didn't they colonize this planet long before we evolved?

Maybe they did.  As long as we are going to speculate, and create wild
hypotheses:

A few billion years ago, some Intelligent Imperial Extra-Terrestrials (IIET's)
noticed that a star had recently formed that had a couple goodly sized
worlds in the liquid-water belt.  So they 'innoculated' them with primitive
life-forms, which eventually evolved into us and the martians.  The martians,
since they lived on a smaller world, with less atmosphere, evolved
intelligence first, being subject to a higher mutation rate. They either
decimated their environment or made it out of the planetary system, or
whatever, died for some reason.  Maybe they were never there.  Who cares,
really?  We're the ones that matter in this discussion.

So why don't we see IIET's?  For the same reason that people aren't allowed
to fly over the White House, or muck around in other people's experiments:
The head honchos said so, because they wanted to see what happened, and
didn't want anyone interfering, and are mean, ugly, mother****ers with
really bad breath and no manners or stylish clothes.  So the ET's that
actually ARE intelligent stay away from us, out of fear.

See, they (the one's in charge) are curious about the origin of life, too,
and hope our biosphere's changes will shed some light on the subject.   No
one uses planets to LIVE ON anymore, so why not use them for cool biological
experiment stations?

Of course, some rouge has to horse around, drop by, maybe, and create
stupid artifacts (Mars-Face, Tekites, Giza) to fuel their ego, giving
us a rich UFO/God legend.  They probably get their asses kicked as soon
as they try to sneak home (gamma-ray bursters?) as punishment.

Just an idea, of course, but it does explain some observations.

I mean, if these IIET's (which Fermi suggested had the ability to
colonize different stars) wanted to, they would have the power to
isolate particular stellar systems, work over billion-year periods, or
kill off dangerous, toxic life-forms (The Martians) after they developed
inter-stellar travel (or broke quarantine, depending on your point-of-view).

On the other hand:

The Sun is about 5E9 years old.  The Earth is about the same age.
A sun so bright as to have a significantly higher mutation rate
would burn out before anything really got going.  And the Milky Way,
depending on your source (theory) is anywere from the sun's age to
20e9 years old.  Let's assume that it's true that galaxies are darn
violent until they get kinda old.  Maybe, we've evolved as fast as
life could in the galaxy, and there's lots of life out there,
but none of it is significantly farther along than us, so it hasn't
looked that far (yet).

Questions to address:
 How fast do inter-stellar colonizers move? (No data)
 How soon did life-bearing conditions arrive, galaxy-wide? (Other galaxies?)
 What are life-bearing conditions?  (Water vs methane, C vs. Si, etc.)
 Any question that fills in the drake equation (Honey?  Where's the darts?)

I believe this has all been hashed through before.  Maybe the interested
should scope the archives.

-Tommy Mac                     .  "                  +
.------------------------  +                      *       +
|   Tom McWilliams; scrub       ,     .                        "        +
|  astronomy undergrad, at     *       +;.     .  '             There is
| Michigan State University   '                      .    "   no Gosh!
|   [e-mail]                        '      ,   *
|       [phone]       ;  +  '                                 *
'-----------------------

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

Date: 7 Aug 92 12:47:10 GMT
From: [e-mail]
Subject: Galileo issues
Newsgroups: sci.space

Why use Cassini as a relay for Galileo?

Cassini could act as a relay for Galileo to empty its flight recorder,
*while* continuing to perform science at Jupiter itself, storing  the
information on *its* recorder.

No matter how much better Cassini's instruments are than Galileo, Cassini
will be flying faster and further from Jupiter and its moons than Galileo.

--- Maximus 2.00

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

Date: 7 Aug 92 17:45:42 GMT
From: Stan Ryckman <alden!sgr>
Subject: Giotto - First Results from Comet Encounter
Newsgroups: sci.space,sci.astro

In article <[e-mail]> [e-mail] writes:
>ESA News Release

[...]

>     At 15:30:56 the Dust Impact Detectors reported the first impact of
>a fairly large particle, followed by two smaller ones.

What is the range of "fairly large?"

Thanks,
Stan.
--
This .signature has expired.  Call 1-900-YOU-FOOL to find out why.
    Stan Ryckman   [e-mail]

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

Date: 7 Aug 92 20:44:27 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Iron, stars, and magnetic fields (was Re: Red-blooded ET's : )
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] writes:
[Quoting Paul Dietz here, but Dale doesn't have spiffy newsreaders
that retain attribution of earlier articles and insert ">'s"
easily...]
>> The Sun also has a magnetic field, as do many stars.  They have
>> little iron (all of it vaporized).  The interaction of convection
>> and magnetic fields on these bodies causes all sorts of interesting
>> effects.
>
> Stars not only have Fe, they are the producers of it. [...]
> Fe is the end product of
> nucleo-synthesis... that is when supernova's happen in big stars.

Dale, you sure have chutzpah giving Paul Dietz a hard time on a topic
like this!

Paul was responding to somebody who claimed that a planet couldn't
have a magnetic field unless it had iron.  He pointed out that
Jupiter, and stars, have big fields despite having very little iron
(as a fraction of their composition).  He's right.

And the iron in a star has just about *nothing* to do with the
origin or behavior of its magnetic field.

Bill Higgins          |  If we can put a man on the Moon, why can't
Fermilab              |  we put a man on the Moon? -- Bill Engfer
[e-mail] |  If we can put a man on the Moon, why can't
[e-mail]   |  we put a woman on the Moon? -- Bill Higgins

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

Date: Fri, 7 Aug 1992 20:10:36 GMT
From: Martin Connors <[e-mail]>
Subject: Meteor Soaks Datona FL
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] (Jim Scotti x2717) writes:
> if it survived intact.  A 1 meter object deposits about 0.6 kilotons of
> TNT equivalent into the atmosphere/ground, while a 10 meter object ...
> I would conclude that the probability of
> seeing impacts of objects larger than 1 meter diameter is very high and
> that it would require an object of at least a few meters to have caused
> a wave as seen in this case.  A 1 meter object would likely not strike
> the surface with enough velocity to cause "a darn sight more than a
> splash", though it would make a nice little splash.

The key here is 'atmosphere/ground' - for this specific case I have not
yet seen any reports of sound which would certainly be loud in the case of
an object able to make a large wave. How could an object get down to the
ocean surface and be seen but not be heard?

Martin Connors - Space Research - University of Alberta

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

Date: 5 Aug 1992 18:51:02 GMT
From: Chuck Shotton <[e-mail]>
Subject: More second-hand info on TSS
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Mark
Bixby) wrote:
>
> I was monitoring shuttle air-to-ground on my scanner this morning at 0700 PDT
> 8/5/92 and at that time the TSS had been deployed to a length of 800 (feet?
> meters?).  Attempts at increasing the length kept failing, due to the vernier
> motor at the end of the boom failing to maintain tension on the tether.  An
> intermittent clutch failure is suspected.

Running 12 miles of cable off a spool doesn't seem to be a particularly
difficult task, even in zero G. Why is it that we have another
over-engineered solution that has apparently failed? Is this really any
more difficult to engineer that an elaborate fishing reel? I'm sure it's a
LOT simpler than most other shuttle systems (including the toilet!).

It's a little discouraging to continually see minor things screwing up
over-hyped shuttle missions (like non-functional grapple bars, jammed fax
machines, burned out cooling fans, untested telescope mirrors, etc.)

I'm not flaming anyone. I seriously want to know how this cable mechanism
was designed and tested and how such a simple mechanism can be so screwed
up.

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

Date: Fri, 07 Aug 92 19:09:19 GMT
From: Ithlial the Archer <[e-mail]>
Subject: Origin of Life article
Newsgroups: talk.origins,sci.skeptic,sci.space

In article <[e-mail]> David O Hunt <[e-mail]> writes:
>

>>   Just to nit pick, but given a fair coin, the previous 1,000,000
                   ^^^^^
>>   tosses have absolutely no bearing on the next.  The odds of the
>>   next toss being tails are still 50-50.
>
>You forget the possibility that we're dealing with a loaded coin!  :)
>
>David,

Can you read or have you forgotten how? 8}  If it is loaded this only makes
the probability lopsided, the extreme case is a two -headed or -tailed
coin.  In this case the prob is 1:0 or 0:1.  In any event the trials
are still independent.

Ithlial

To me, boxing is like ballet, except there's no music, no choreography,
and the dancers hit eachother.

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

Date: 7 Aug 92 20:03:09 GMT
From: John Roberts <[e-mail]>
Subject: Origin of Life article
Newsgroups: sci.space

-From: [e-mail] (Bob Beauchaine)
-Subject: Re: Fwd: Origin of Life article
-Date: 6 Aug 92 15:59:27 GMT
-Organization: Tektronix, Inc., Beaverton,  OR.

-In article <[e-mail]> [e-mail] (David O Hunt) writes:
->...suppose
->I give you a coin.  You flip it 1,000,000 times, and 999,999 times it comes
->up heads, once tails.  Are you _seriously_ going to tell me that the odds
->of the next one being tails are favorable?  Definite?  Because that's what
->you're claiming with the _overwhelming_ evidence for evolution.

-   Just to nit pick, but given a fair coin, the previous 1,000,000
-   tosses have absolutely no bearing on the next.  The odds of the
-   next toss being tails are still 50-50.  I understand your point,
-   but your analogy is flawed.

Is "given a fair coin" an article of faith? Observation of results alone
would seem to indicate that it *probably* isn't. :-)

There are mathematical formulas for the evaluation of the probability of
a hypothesis being correct given a particular number of observations.
Putting biogenesis into mathematical terms may be of limited usefulness
at this point, because we know so little about it.

John Roberts
[e-mail]

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

Date: 7 Aug 92 22:43:23 GMT
From: "R. Kym Horsell" <[e-mail]>
Subject: Origin of Life article
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>There are mathematical formulas for the evaluation of the probability of
>a hypothesis being correct given a particular number of observations.
>Putting biogenesis into mathematical terms may be of limited usefulness
>at this point, because we know so little about it.

This is rather misleading. The area alluded to is called induction.
To consider the difficulty of comming up with such formulae -- consider
the following. An event happens ``n'' times in a row. What is the
prob of it happening the ``next time''. You may say: n/n=1 (i.e.
it is certain to happen). You may say 1/2 (i.e. 50:50) or you
may say 1/(n+1). This last formula is meant to be a compromise
(we have learnt _something_ from the string of n events; but
there is still some uncertainty).

All formulae above can be used (so far as I know) interchangabley;
none leads to a contradiction. (Unless you set up your system of
math logic to, e.g., specifically preclude it :).

There are thus no ``mathematical formulas for evaluation of
the probability of a hypothesis''. Various statisticians will
give me an argument. But they are wrong. :)

-kym

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

Date: 7 Aug 92 22:11:05 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Oxygen pills for EVA (was Re: Medicine for space walks)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (SCOTT I CHASE) writes:
> to prepare for [EVA]
> contingency, the appropriate crew members had been instructed to take
> some medication necessary for space walks.
>
> What was he talking about?  What does it do?

Don't know about NASA, but on *Fireball XL5* (once my favorite TV
show),  whenever the crew needed to leave the ship they took "oxygen
pills" first. Then they strapped on rocket thruster packs and floated
out the hatch.

This system eliminated the need for space suits.  A good thing, too,
because the XL5 was crewed by marionettes, who find it difficult to
don spacesuits.  It's hard to get a good seal around the strings.

(How marionettes even survived in a weightless environment, without
getting tangled, is something I never quite figured out.)

     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     [e-mail]
   -   -       Internet:  [e-mail]
     ~         SPAN/Hepnet:      43011::HIGGINS

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

Date: 7 Aug 92 17:15:29 GMT
From: Mark Littlefield <[e-mail]>
Subject: Question about shuttle launches
Newsgroups: sci.space

'lo all,

A thought occured to me the other day and I havn't been able to find
an answer on my own, so I thought I'd ask the net.  Does anyone know
if the shuttle cargo bay is evacuated (all the air sucked out) before
a launch.  It would stand to reason that if it were not, the shuttle
would be dragging a bunch of mass to orbit that it would not need to.

Along that same reasoning, SSF modules could be launched evacuated, or
at least at a reduced pressure, to help save weight.

Thanks in advance,

mark


--
=====================================================================
Mark L. Littlefield              Intelligent Systems Department
internet: [e-mail]
USsnail:  Lockheed Engineering and Sciences
          2400 Nasa Rd 1 / MC C-19
          Houston, TX 77058-3711
====================================================================

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

Date: 7 Aug 92 20:34:08 GMT
From: Henry Spencer <[e-mail]>
Subject: Question about shuttle launches
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>know if the shuttle cargo bay is evacuated (all the air sucked out) before
>a launch...

It's not.  The bay is at more or less the outside pressure at all times,
meaning that it slowly bleeds off pressure as the shuttle ascends.

>would be dragging a bunch of mass to orbit that it would not need to.

The mass of the air in the bay is really miniscule.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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

Date: 7 Aug 92 20:50:32 GMT
From: Jim Dumoulin <[e-mail]>
Subject: Question about shuttle launches
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Mark Littlefield) writes:
> 'lo all,
>
> A thought occured to me the other day and I havn't been able to find
> an answer on my own, so I thought I'd ask the net.  Does anyone know
> if the shuttle cargo bay is evacuated (all the air sucked out) before
> a launch.  It would stand to reason that if it were not, the shuttle
> would be dragging a bunch of mass to orbit that it would not need to.
> Along that same reasoning, SSF modules could be launched evacuated, or
> at least at a reduced pressure, to help save weight.
>
> Thanks in advance,
> mark

  The shuttle cargo bay is not evacuated before launch but it is
  usually purged with GN2.  The cargo bay isn't a pressurized container
  and is therefore impossible to evacuate.   Most hollow structures
  in the shuttle as well as ground support areas are "inerted" with
  Nitrogen to cut down on the fire risk.  Of course, this increases
  the risk to ground personnel and has been the cause of a death at
  KSC due to oxygen deprivation.  This occured many years ago and there
  are many safety procedures in place to insure it will not happen
  again.

--------------------------------------------------------------------------
   Jim Dumoulin                      INTERNET: [e-mail]
   NASA / Payload Operations      SPAN/HEPnet: KSCP00::DUMOULIN
   Kennedy Space Center
   Florida, USA  32899



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

Date: 7 Aug 92 19:56:32 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Source of moon/apollo pix
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Mike Smithwick) writes:
[...Mike found his old Apollo 15 Moon slides]
> These were published by a company called "Holiday Films". Anyone know
> if these people are still around? If not, anyone know of a good source
> of Apollo or Moon (lunar orbiter, etc.) slides (or gifs).

Finley Holiday Films is still in business.  Information on ordering
from them is given in the FAQ (Frequently Asked Question) posting.

The Lunar and Planetary Institute has some interesting slidesets on
the Moon, too, I think.

I suspect the Moon just is *not* available in digital form.... though
Dennis Wingo has talked about digitizing some of the Lunar Orbiter
microfiche just for fun.  The USGS people in Flagstaff would know more
than anybody about the availability of Moon data.

Submarines, flying boats, robots, talking         Bill Higgins
pictures, radio, television, bouncing radar       Fermilab
vibrations off the moon, rocket ships, and        [e-mail]
atom-splitting-- all in our time.  But nobody     [e-mail]
has yet been able to figure out a music           SPAN:  43011::HIGGINS
holder for a marching piccolo player.
                     --Meredith Willson, 1948

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

Date: Fri, 7 Aug 1992 22:22:34 GMT
From: Edmund Hack <arabia!hack>
Subject: Source of moon/apollo pix
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Bill Higgins-- Beam Jockey) writes:
>I suspect the Moon just is *not* available in digital form.... though
>Dennis Wingo has talked about digitizing some of the Lunar Orbiter
>microfiche just for fun.  The USGS people in Flagstaff would know more
>than anybody about the availability of Moon data.

According to my contacts at JSC and LPI, none of the Lunar Orbiter or
Apollo CSM photography is in useable digital form.  All that exists for
Apollo are long rolls of B&W prints (and the negatives) and maps made by
USGS and DMA from the stereo pairs.  A project I am working on part-time
may turn some of the photography and cartography data from the landing
sites into digital terrain maps.

Due to the early date of the lunar spacecraft designs, the maps we have
of Mars are more comprehensive and accurate than those of the moon.


--
| Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
| [e-mail]    SpokesPersonp(Me,or(NASA,LESC)) = NIL
| "No the game never ends when your whole
|       world depends on the turn of a friendly card"

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

Date: 7 Aug 92 13:36:25 CDT
From: Alan Kilian <[e-mail]>
Subject: Two questions about the shuttle tethered satellite experiment
Newsgroups: sci.space,sci.space.shuttle

I have two questions about the tethered satellite experiment:

1) The shuttle is at one end of a conductive wire. The satellite is at
   the other. If the wire moves through a magnetic field you can generate
   an electric potential. Now how do you measure the potential?
   They were hoping for 5000 Volts on a 12 Mile tether but got 40 Volts
   on a 750 Feet tether.

2) Why does the ball (It's easier than satellite) keep moving away from
   the shuttle as you unwind the tehter?

3) (I know I said two but what the heck) How can you use the potential
   from the one wire tether?

                         -Alan Kilian
--
 -Alan Kilian           [e-mail] 612.683.5499 (Work) 612.729.1652 (Home)
  Cray Research, Inc.   655 F Lone Oak Drive, Eagan  MN, 55121
                        "It's based on actual math". -Dilbert

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

Date: Fri, 07 Aug 92 18:25:49 EDT
From: Tom <[e-mail]>
Subject: Water-worlds

>> There is no reason to believe that our solar system is unusually
>>heavily populated in its inner regions, and indeed considerable reason
>>to believe that it is fairly typical.  Based on what we know now, most
>>any planetary system around a reasonable star should have at least one
>>planet in the liquid-water zone.  The major uncertainty is whether
>>that planet will be the right size for its location.  The odds of that
>>aren't 100% by any means (Earth hit, Mars missed), but they aren't one
>>in a million either.  One in two?  Maybe one in ten if you're a pessimist.

>Sample of one. All reports of extrasolar planets have been super Jovian.

But our methods for detecting other planets can only find Super-Joves (and
brown dwarf companions, etc.)

>We don't know if liquid-water zone planets are likely or not.

But we can trust the anthropic principle at least as much as anything else
in this context (We aren't unique).  Of course, I can include my 'Moon
as proof of God' for an example of deviation from the anthropic priciple,
if you care to hear it.  (Earth-moon is a binary planet: Unusual by
solar standards)

>Certainly as a percentage of total solar system volume, the liquid water
>zone is small. Other stellar types also have liquid water zones of different
>extents.

As a percentage of planets formed, we get 1/9th, not including 'stroids.

For that matter, the 'planet-forming' zone is small, compared to the
heliopause, so that percentage strikes me as meaningless.

Example:  The liquid water zone is pretty darn big, compared to the
rocky-planet zone.

I seem to recall that simulations based on the 'solar nebula' model almost
always produce a rocky planet or two in the liquid water zone.  Anyone
know more about this?

-Tommy Mac                     .  "                  +
.------------------------  +                      *       +
|   Tom McWilliams; scrub       ,     .                        "        +
|  astronomy undergrad, at     *       +;.     .  '             There is
| Michigan State University   '                      .    "   no Gosh!
|   [e-mail]                        '      ,   *
|       [phone]       ;  +  '                                 *
'-----------------------

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

Date: 7 Aug 92 19:38:11 GMT
From: John Eisenberg <[e-mail]>
Subject: Weird circle-like things on shuttle map
Newsgroups: sci.space

On the NASA channel, when they display the globe with the
shuttle moving around, there are all these cirlce-like things
that have strange grooves.  They seem to all be around places
that could track or serve as emergency landing areas.

What are they and why are they shaped as they are?


Thanks,

John.

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

Date: Fri, 7 Aug 1992 19:55:33 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Weird circle-like things on shuttle map
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Eisenberg) writes:
>On the NASA channel, when they display the globe with the
>shuttle moving around, there are all these cirlce-like things...

>What are they and why are they shaped as they are?

Those are called Crop Circles. Nobody knows what causes them.

 Allen

PS. :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-)

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------259 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 7 Aug 92 20:36:47 GMT
From: Henry Spencer <[e-mail]>
Subject: Weird circle-like things on shuttle map
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Eisenberg) writes:
>On the NASA channel, when they display the globe with the
>shuttle moving around, there are all these cirlce-like things
>that have strange grooves.  They seem to all be around places
>that could track or serve as emergency landing areas.
>What are they and why are they shaped as they are?

Those are the areas where a shuttle at orbital altitude is in line-of-sight
(for radio transmissions) of a ground station in the center of the circle.
There are bites out of some of them because of things like mountains that
block the view in some directions for some stations.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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End of Space Digest Volume 15 : Issue 085
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