Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_3/V15NO388.TXT

Internet Message Format | 1993-07-13 | 33KB

Date: Sat,  7 Nov 92 05:00:10
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #388
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat,  7 Nov 92       Volume 15 : Issue 388

Today's Topics:
              "Earth Gains a Retinue of Mini-Asteroids"
          ANSWER: Recognizing a Dyson sphere if you saw one
              Coverup - gravity doesn't exist? (2 msgs)
                  Expected cost of Asteroid Impacts
             Hubble's mirror  or Really Costar. (2 msgs)
                   IS SWIFT-TUTTLE THE REAL THREAT?
                           Magellan CD-ROMs
                        Mars over the Moon???
        Moon can hold its air (was Re: Mars over the Moon???)
                             Nasa Coverup
                       Nuclear waste to Venus?
                             on coverups
                                Oops!
                             Plant growth
                                RD-701
                              Space Law
            Swift-Tuttle Comet a threat to earth? (2 msgs)
                 Swift Tuttle and the satellite belt

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Fri, 6 Nov 92 15:58:38 GMT
From: [e-mail]
Subject: "Earth Gains a Retinue of Mini-Asteroids"

> By the way, the Tuguska event was observed by residents of the

> region and their description of the explosion matchs that of a
nuclear
> bomb blast quite closely.
>


Thanks. I had not heard that. I was thinking in terms of small icy
objects with a downward moving shockwave shattering and spreading
their energy over a wide region rather than a fireball with the
energy density necessary to create a rapidly rising column with
entrained air/debris. The photos and information I had previously
been aware of seemed to indicate an effect more like the mother of
all downbursts for Tunguska. :-)

With objects sized on the order of Barringer I can well imagine the
mushroom cloud occuring: the energy is released very rapidly and in a
very small area. Although at a certain size the explosion simply
blows a hole in the atmosphere, ie it is a circular curtain rather
than a mushroom cloud.

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

Date: Fri, 6 Nov 1992 08:31:29 GMT
From: Steve Linton <[e-mail]>
Subject: ANSWER: Recognizing a Dyson sphere if you saw one
Newsgroups: sci.astro,sci.space

In article <[e-mail]>, [e-mail] (Frederick A. Ringwald) writes:
|> In article <[e-mail]>
|> [e-mail] (Erik Max Francis) writes:

|>
|> No - the main point to the article is that the filling factor does not
|> necessarily have to be high, so plenty of light from the central star
|> would get through. What we'd see is a Sun-like star, with a small IR
|> excess indicating a 300 K shell with size on the order of 1 AU: in
|> other words, something not necessarily easily distinguishable from a
|> natural object. Unless there's something obvious, such as narrow-band
|> radio signals...

I thought the whole point of a Dyson sphere was to utilise the whle energy of the
star, reradiating it as waste heat at some low temperature. I suppose the DS
might not be finished yet, but it strikes me as the sort of thing you build
completely or not at all.

A civilization that is using a substantial proportion of its star's energy would
look like what you describe, but might simply have a large constellation of
orbitting power stations.

I guess it all comes down to definitions.

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

Date: Fri, 6 Nov 92 08:22:19 EST
From: John Roberts <[e-mail]>
Subject: Coverup - gravity doesn't exist?

-From: [e-mail] (Peter J. Scott)
-Subject: Re: NASA Coverup
-Date: 5 Nov 92 18:24:25 GMT
-Organization: Jet Propulsion Laboratory, NASA/Caltech

-Ah, but have you personally verified Newton's Law of Gravitation?  After
-all, who do you think started this whole conspiracy?  Can any of us say
-that we really knew Isaac Newton?

*I* haven't, but my roommate in college did. He was a pretty honest fellow,
so I expect he was telling the truth about the results.

There's an apple tree on the NIST grounds that's a direct descendant of the
tree Isaac Newton was sitting under when he thought up the laws of gravitation.
I suppose we could set up a video camera and determine whether there's
anything unusual about the trajectory of the apples falling from that
particular tree. If they just float in midair or gently drift to the ground,
then there's reason to suspect that Isaac made the whole thing up.

:-)

John Roberts
[e-mail]

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

Date: Fri, 6 Nov 1992 18:21:40 GMT
From: Nick Haines <[e-mail]>
Subject: Coverup - gravity doesn't exist?
Newsgroups: sci.space

John Roberts writes:

   Peter J. Scott writes:

   -Ah, but have you personally verified Newton's Law of Gravitation?  After
   -all, who do you think started this whole conspiracy?  Can any of us say
   -that we really knew Isaac Newton?

   *I* haven't, but my roommate in college did. He was a pretty honest fellow,
   so I expect he was telling the truth about the results.

I've done an inverse-square experiment (not very well), and a big-G
experiment. But gravity is genuinely very difficult to test
accurately. That's why there are still a fair number of people
experimenting with it (and every so often one of them comes up with
evidence for gravitational mass depending on, say, baryon number (I
kid you not)).

   There's an apple tree on the NIST grounds that's a direct
   descendant of the tree Isaac Newton was sitting under when he
   thought up the laws of gravitation.

Cobblers. No such tree. I have, however, bathed in the fountain that
Byron's bear used to play in :-)

Nick Haines [e-mail]

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

Date: Fri, 6 Nov 1992 19:24:10 GMT
From: Nick Haines <[e-mail]>
Subject: Expected cost of Asteroid Impacts
Newsgroups: sci.astro,sci.space

Well, thanks to Duncan Steel for some figures. I've done some
back-of-envelope calculations, and come out with this conclusion:

If we (as a world economy) spent $350 billion this year, and as a
result could guarantee there would be no future impacts by 1km bodies,
this would be money well spent.

Nick Haines [e-mail]

Working:

Probability of a ~1km impact is, say, 1e-5 per year. The effect of
such an impact, I guess, would be to reduce the world economy to 1% of
its current value, which it wouldn't recover for about a century (n.b:
this does not cover impacts of bodies substantially larger than 1km).
So in a cost analysis, the cost of such an impact in any year would be
about 50 times the gross world product for that year, and the expected
loss in any given year (assuming a non-growing economy) is 5e-4 the
GWP. GWP this year is about $2e13, so the expected loss (if this were
stable) would be $1e10 (ten billion dollars).

However, the GWP is not fixed. It grows at about 2% per annum. Cost of
an impact in 2126 would be more than $1.4e16 in 1992 dollars. Expected
loss _for_this_year_ is $1.4e11 in 1992 dollars. Using a figure of 5%
real return on investment, this backdates to $200 million we should
spend _this_year_ to avoid an impact in 2126. And a similar number to
avoid impact in 2127. And so on. The total works out to be

impact * current GWP * 50 * (invest / (invest - growth))

where we're using 1e-5 for impact, 1.05 for invest and 1.02 for
growth, giving $350 billion.

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

Date: Fri, 6 Nov 1992 13:02:30 GMT
From: Pat <[e-mail]>
Subject: Hubble's mirror  or Really Costar.
Newsgroups: sci.space

Ball Aerospace is making costar, and it's  a prety interesting instrument.

it's essentially three little mirrors on a sliding arm on a giant optical
bench (phone booth sized).  each of the little mirrors is calibrated
to adjust each of the intruments.

now here is my question.

why not design costar to also add filters.  given wf/pcs aversion
to the moon and sun,  if you put a filtering mirror in also,  could
you then conduct  really hi res lunar imaging?  or is this just pointless
cuz we already have more then enough capacity.

also if you can put in filters,  i think you could reduce the cone of avoidance
around both the sun and moon,  filters on, slew aroundthe sun to target
filters off.  i would think simpler and easier then the complex
pirouette they do now and safe rthen closing the main aperture door.

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

Date: Fri, 6 Nov 1992 16:56:38 GMT
From: [e-mail]
Subject: Hubble's mirror  or Really Costar.
Newsgroups: sci.space

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

> why not design costar to also add filters.  given wf/pcs aversion
> to the moon and sun,  if you put a filtering mirror in also,  could
> you then conduct  really hi res lunar imaging?  or is this just pointless
> cuz we already have more then enough capacity.

If you get direct sunlight onto the cassegrain secondary you risk breaking
it.  You are also faced with a problem when trying to acquire guide stars
if imaging the moon.  Guide craters have been suggested but the brightness
per unit area is too high for the Fine Guidance Sensors.  Finally, COSTAR
has corrective optics for the FOS, GHRS, and FOC only.  WF/PC II contains
its own corrective optics but still won't be used for solar or lunar
observations.  Interestingly, we use the Earth as a flat field source
all the time with the FGS's paused.  WFPC doesn't mind a bit.

> also if you can put in filters,  i think you could reduce the cone of avoidance
> around both the sun and moon,  filters on, slew aroundthe sun to target
> filters off.  i would think simpler and easier then the complex
> pirouette they do now and safe rthen closing the main aperture door.

You still risk the secondary if you do this.  Since HST has no front end
energy rejection filter it is unwise to get anywhere near solar pointing.
Also, we don't close the aperture door under normal operations.  It only
closes in a deep safe mode.

As for an annoying problem, the South Atlantic Anomaly and flapping of
the solar arrays give a lot more headaches around here than solar avoidance.

-Bill Gawne,  Space Telescope Science Institute

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

Date: Fri, 6 Nov 1992 13:27:34 GMT
From: [e-mail]
Subject: IS SWIFT-TUTTLE THE REAL THREAT?
Newsgroups: sci.astro,sci.space

=========================================================================

The Comet Swift-Tuttle saga : an addendum  - Duncan Steel, 1992 November 6th


One thing that no-one has picked up on so far, it seems, is that it is more
likely that an asteroid or comet big enough to wipe out mankind will hit
the Earth before P/ST may perchance clobber us on 2126 August 14th than
the probability of that comet itself doing the job.  That was a mouthful,
but think about it: what I am saying is that even IF P/ST does hit the
Earth on that date there is a chance that we may have already been hit by
some other as-yet undiscovered object.

A very crude estimate of the chance of P/ST hitting, a priori (that is at
this stage without the observations to be made over the next decade) is
about 1 in 10,000.  That is, the perihelion date is uncertain by about
25 days, and if it does come back so as to pass its node on 2126 August 14th
then since it takes about 3.5 minutes to cross the Earth's path and
24 hours = 400 x 3.5 minutes, more-or-less, the probability is about 1 in
25 x 400 = 10,000.

However, if there are about 3,000 Earth-crossing asteroids larger than 1 km
in size (that is about the size limit for a global catastrophe, depending upon
mass and impact speed) and these have a mean collision probability with our
planet of about 6 x 10^(-9) per year (see Steel & Baggaley, MNRAS, 212, 817,
1985) then one expects one impact by such an object every ~50,000 years.
[See also the discussion in the Spaceguard Survey report, ed. D. Morrison].
That figure may be a little on the high (frequent) side, but I would plump
for one per 100,000 years as being in the right ball park.

This means that in the next century there is about a 1 in ~1,000 chance of
a 1 km asteroid dropping in to play (havoc).  This is 10 times our current
estimate that mankind will be stuffed by P/ST in 2126.  Note that no comets
(either SP or LP) have been included in my sum, and these may comprise
about 25% of the total risk (i.e. asteroids 75% of the hazard).

Now, people get all upset about such calculations for asteroids and comets
and say that the public should not be alarmed.  In fact there are some of
us around who think that there is every reason to be alarmed: not panic-
stricken, just alarmed.  It's about time we took out some insurance against
this hazard.  Yes I do have a vested interest in that this is my area of
work; but I have that vested interest since I have directed myself this way
since I did the sums referred to above over 8 years ago and found that the
results were worrying.

In order to get politicians on the track nowadays, everything has to be done
in terms of economical arguments.  To that extent I commend to you for
perusal the "Mr Statistics" column in FORTUNE magazine for 1992 June 1st.
There it is shown that the annual expectancy of economic loss to the US
alone from asteroid impacts is of order $750 million; and that figure is
derived using a far-too-low probability of impact by a mankind-killing
object of one in a million per year, whereas in fact the estimate of that
probability should be more like 1 in 100,000.  Note that this is the "US
alone" figure (i.e. sod everyone else in the world), and it considers only
the infrequent huge impacts with global effects.  One could add on to that
annual expectancy the much more frequent smaller impactors to get a rather
higher sum.  For example, a Tunguska over Tokyo would bankrupt not only
the US but also the rest of the western world.  Most certainly the
Australian economy could not survive the withdrawal of all Japanese
investment here which would follow from a levelling of Tokyo.

Yes I know that it all sounds very melodramatic and over-stated; but
just look at the numbers.  I am not suggesting that $750 million p.a.
should be spent on looking for these damned things to see whether there are
any due to hit us in the next century; but NOT to spend the $300 million
over 20 years required for Spaceguard would be crazy, and false economy.
Nor am I suggesting that the US should pick up the tab: an international
program is needed.  I pisses me off to hell that my own countries
(Australia and the UK) are doing absolutely nothing, indeed with our
own search program here, the only one covering the southern sky, being
terminated in a few weeks.

Take this seriously, guys, and lobby.  NASA's Spaceguard program must be
implemented, and the time to strike is now.


=========================================================================

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

Date: Sat, 7 Nov 1992 00:59:19 GMT
From: Ron Baalke <[e-mail]>
Subject: Magellan CD-ROMs
Newsgroups: sci.space,sci.astro,alt.sci.planetary,alt.cd-rom,sci.geo.geology

                     =====================================
                             MAGELLAN CD-ROMs
                                 Cycle 2
                             November 5, 1992
                     =====================================

     Fourteen more Magellan CD-ROMs (volumes 53 through 66) have now
been released by the Magellan project.  A total of 77 Magellan CD-ROMs
are now available: 66 CD-ROMs containing radar images, and 11 CD-ROMs
containing altimetry data.  Volumes 1 through 52 contain the radar
images taken by the Magellan spacecraft during Cycle 1, the first 8 month
mapping of the planet Venus.  Volumes 53 through 66 are the first release
of the Cycle 2 radar data.

     The CD-ROMs can be obtained from the National Space Science Data Center
(NSSDC) at the Goddard Space Flight Center.  The "nominal" charge is $20 for
the first CD-ROM, and $6 for any additional CD-ROM in an order.  However,
NSSDC may waive this charge for a small amount of data requested by bona fide
research users, government laboratories, etc.  School teachers who are unable
to pay may be helped on a case by case basis, and/or as resources permit.
Researchers funded by NASA's Solar System Exploration Division can also obtain
the CD-ROMs through the Planetary Data System at JPL.

     NSSDC's address is:

    National Space Science Data Center
    Goddard Space Flight Center
    Greenbelt, Maryland 20771
    Tel: [phone]

        Email address:   [e-mail]

     You can also reach NSSDC by logging on to their computer.  To log onto the
NSSDC computer, telnet to NSSDC.GSFC.NASA.GOV and give the username "NSSDC".
You will then be connected to a menu system which allows you to use the
"Master Directory".  You can also leave questions and orders for the NSSDC
staff.  If this is the first time you have used the NSSDC "NODIS" system, it
will ask you for information (name, address, ...) to keep a database of NSSDC
users.

     NSSDC also provides the following software to display the images:

        o IMDISP       (IBM PC)
        o Browser      (Macintosh)
        o Pixel Pusher (Macintosh)
        o True Color   (Macintosh)

     The Magellan CD-ROMs will also eventually be available at the anonymous
ftp site at the Ames Research Center: ames.arc.nasa.gov [128.102.18.3].
The Ames site has two CD-ROM drives and they are accessible through the
pub/SPACE/CDROM and pub/SPACE/CDROM2 directories.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Give people a second
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/  |_|/       |_____|/                     |

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

Date: 6 Nov 1992 13:26:43 GMT
From: "Dr.Savory" <[e-mail]>
Subject: Mars over the Moon???
Newsgroups: sci.space

Any body to be terraformed should have sufficient gravity to retain
an atmosphere (obvious?), so exclude the moon, OK ;)

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

Date: 6 Nov 92 15:45:20 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Moon can hold its air (was Re: Mars over the Moon???)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Dr.Savory) writes:
> Any body to be terraformed should have sufficient gravity to retain
> an atmosphere (obvious?), so exclude the moon, OK ;)

This is unfair to the Moon.  If it were magically given an atmosphere,
the Moon would retain it for a long time, at least thousands of years.

As somebody already mentioned, the Moon is not a good candidate for
terraforming because it has no large native source of volatiles.
However, claiming that it can't hang on to an atmosphere is not valid
for short timescales.

It seems to me that anybody who had the technology to give the Moon an
atmosphere would find it easy to freshen it up every millenium or so
with new gases...

(Should I mention this?  Oh, what the heck, go ahead, Bill.  In the
absolutely clunker TV series *Space 1999* there is an episode where
precisely this happens: a mysterious alien cylinder suddenly gives the
Moon a breathable atmosphere.  The happy human crew of Moonbase Alpha,
who have spend their whole TV career huddled underground or working in
spacesuits, run outside and begin playing volleyball.  We see a shot
from outside a window of Barbara Bain and Martin Landau watching this
magic moment. Then one of them touches a control AND THE MOONBASE
ALPHA WINDOW SLIDES OPEN ELECTRICALLY.

(Back in grade school we used to say, "That makes about as much sense
as a screen door on a submarine.")

Bill Higgins, Beam Jockey              |
Fermi National Accelerator Laboratory  | "Get the dinosaurs in, Martha,
Bitnet:           [e-mail]  |  they're predicting comets."
Internet:       [e-mail]  |      --Dr. Barry D. Gehm
SPAN/Hepnet:           43011::HIGGINS  |

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

Date: Fri, 6 Nov 92 16:58:23 GMT
From: [e-mail]
Subject: Nasa Coverup

>     This is about the last sort of opinion I would expect from someone  from
>    New  Zealand ,of all places. When did you get to vote on what agencies we
>    need in MY government? If you want a National  Security  Agency  in  YOUR
>    government  in charge of keeping embarrassing information hidden from the
>    general public , you are more than welcome to start lobbying for one over
>    there. None of my business.  I suggest you mind yours.
>


If you are going to argue on the net, you had better get damned used to the fact
that national borders don't exist out here in cyperspace. You are not posting to
americans. You are posting to Terrans. I don't think the USA needs any such
organization as NSA either (although I am presently outside of it's facist sphere
of influence, or at least mostly. Besides which, I voted for Marrou.). I would
argue with our New Zealand friend's opinion, but *NOT* with his right to state
it. Nationalism is for Homo Neanderthalis. No...I wouldn't even insult a
neanderthal with the accusation of being in favor of nationalism.

You are arguing your case with a chip on your shoulder. State it if you wish,
argue it if you wish, and be prepared to take the intellectual rough and tumble
of the net. If you can't stand the heat, tough. Most of the rest of us developed
asbetos covered bottoms years ago.


The people you are arguing with are people who deal with the numbers like lunar
gravity every day. How about the ISEE probe that was turned into ICE by multiple
lunar gravity assists? That required very precise knowledge of lunar gravity. The
FAINTEST of inaccuracies would have caused failure. And then there is the huge
mass of gravimetric data gathered by the Lunar Orbiters before the Apollo
flights. All the MASCON data and such was openly available and used (probably by
people who you are are posting to) in many technical papers. ICE was done
flawlessly, and was mostly the work of one or more key people at JPL (you have
some damn smart cookies out there guys!)

If you are not getting much satisfaction, it is because there are people in this
group capable of doing those same orbital calculations themselves, some of whom
have written their own codes for doing them. Some of who have done it for real
launches. A discrepency such as you describe is simply far too obvious to have
been missed.


I mentioned Paul Deitz: he is part of our community here, and is a very respected
part of it at that. If he is not busy with life outside of cyberspace, I'm sure
he could address what you have said, and far better than most of us. If he is
listening in now, it is up to him. Henry (Spencer) is also pretty good, as is Ron
Baalke and a number of other JPL types. Not to mention several dozen real life
professional astronomers.

Neither Buzz nor any of the Apollo astronauts are on the net, to my knowledge.
The truth is that I find some of them unfortuneately too conservative
technologically for my taste. Which doesn't mean that I don't have a lot of
respect for them. They are NOT liars, and they are not the sort to hold with
coverups.

You wished to know about Buzz's problem? Well after he came back, there was no
place to go. No Mars trip that would come in his professional lifetime. A moon
program that was closing down. He had hit the top and had nowhere else to go. So
he climbed into a bottle for awhile. But he got over that and is about as fine a
person as you would want to know. His wife is charming as well. No, he is not a
personal friend, but I have had a chance to chat with him one on one and we (and
Bill Higgins and a few others in the Space Digest) move in some of the same
physical circles. Oh, and none of the above about Buzz is private info. You can
find out as much in public sources. But I'll vouch for it.

And if you are going to try to lump me in as part of your conspiracy, fine. But
t'would be rather strange since I'm a well known (if easy going) libertarian
anarchist with impeccable anti-all-government-smash-the-state credentials. As I'm
sure many old timers here can testify :-)

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

Date: Fri, 6 Nov 92 08:30:24 EST
From: John Roberts <[e-mail]>
Subject: Nuclear waste to Venus?

-From: [e-mail] (Lauren Podolak)
-Subject: Re: Drop nuc waste into
-Date: 4 Nov 92 23:03:02 GMT
-Organization: Mechanic: The Usenet<->Fidonet Gateway oF St. Pete Florida

-HS>Actually, as Larry Niven pointed out, if you can get the stuff as far as
-HS>Venus, you might as well just fly it *into* Venus.  It's not as if Venus
-HS>is good for anything else.  (Although one would want to do rather more
-HS>thorough studies of Venus before starting to use it as a dump...)

-Why do that?  Conceivably Venusian terraforming could be done and now
-you've contaminated it with radioactives.  If dumping is the solution
-dump on an airless body.

Without working too hard at the math, I strongly suspect that cleaning up
a few million tons of high-level radioactive waste would add far less than
a thousandth of a percent to the cost of terraforming Venus. With that kind
of cost ratio, it would be an insignificant impediment to terraforming.

This is not to say I favor the idea - I think the nuclear waste should be
kept on the Earth.

John Roberts
[e-mail]

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

Date: 6 Nov 92 04:59:14 -0500
From: "Randolph J. Finder" <[e-mail]>
Subject: on coverups
Newsgroups: sci.space

On coverups.

Any coverup that requires active participation of > 1% of the population
and that is believed by >99% of the population is not exactly something
that I tend to believe is a coverup. Something that I do
like to get from people who believe in coverup is the number of people
who would have to be actively in it.

For example, what % of the population would have to be in on
a conspiracy to make people believe that the earth is round.
at least 50% of employees of NASA, most of the commercial airline
pilots, Anyone who has been to Antartica, and large majorities of
lots of other groups

The other side of it is what is the gain of the groups doing the coverup.
On that basis a JFK conspiracy at least has something going for it.

As an example of an event that was called a coverup and actually was:
the Katyn Massacre. The Katyn Massacre was a killing of a large number
of captured Polish Officers in 1941. Of the people who know what it
is a large number (Most Poles) believed that the Soviets did it rather
than the Nazis, who the Soviets said did it. It also is obvious what
the advantage of the cover-up is. the truth would have caused riots in
Poland against Soviet rule.


--
([e-mail])      | Leadership,Friendship, and Service
([e-mail])      |          Alpha Phi Omega
"The service we render to others  | National (Co-ed) Service Fraternity
 the rent we pay for our room on earth" - Sir Wilfred Grenfell

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

Date: Fri, 6 Nov 92 08:07:54 EST
From: John Roberts <[e-mail]>
Subject: Oops!

-From: [e-mail] (Fran Litterio)
-Subject: Re: NASA Coverup
-Date: 6 Nov 92 00:22:39 GMT
-Organization: CenterLine Software, Inc.

-Recall that astronauts did sometimes fall down on the moon and had to
-be helped up due to the bulkiness of the suits.  That's one reason why
-there were always two of them out at once.

-Then the was the time an astronaut caught his foot on a cable and
-knocked over a rack of million dollar equipment.  It was useless
-thereafter (anyone know who did that?).

It was our hero, John Young, who later went on to fame and fortune in the
Shuttle program. He yanked the cable out of the heat flow experiment, and
it couldn't be repaired in the time available. This was a significant loss,
because relatively few of the Apollo missions carried heat flow sensors.

He *did* say he was very sorry. :-)

John Roberts
[e-mail]

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

Date: Fri, 6 Nov 92 13:16:25 GMT
From: [e-mail]
Subject: Plant growth

I'm aware of several studies. There was a group at (I think)
University of Arizona that had a rotating chamber with lettuce and
such growing on the inside.

There was at least one paper presented at the second Lunar Base
Symposium.... (I'm STILL waiting for my proceedings on that. Anyone
else heard anything?)

There also have been experiments on MIR and some seed germination
experiments on the shuttle.

(I'll bet Henry has already responded with a bibliography. Just
*WAIT* until I get my file cabinet on line Henry!!! :-)

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

Date: Fri, 6 Nov 92 13:20:09 GMT
From: [e-mail]
Subject: RD-701

>     Av. Week had a second article on the NPO RD-701, a tri-fuel
> engined which burns kerosene, LOX, and LH2, with continuously
variable
> fuel transition from kerosene to LH2.  Is this to customize the
rocket
> performance as a function of altitude, load, etc.?  The thrust
figures
> for all kerosene were significantly higher than with pure LH2.
>


Very interesting. Gary Hudsen's original SSTO design used a dual mode
engine. You use the denser fuel to get off the ground and switch to
LOX/LH2 at altitude. I would think you would need a dual expander as
well (this appears in all the early Phoenix-E drawings). How do the
russians handle that?

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

Date: Thu, 5 Nov 1992 10:59:48 -0500 (EST)
From: [e-mail] (Tricia Porth [phone])
Subject: Space Law

I am trying to find a source which lists references to space,
astronautics, and aeronautics laws and gives a brief synopsis of
each law.  This is a tall order, but someone out there knows of
a book or report which can help me, right???
Thanks!

Tricia Porth
[e-mail]

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

Date: 6 Nov 92 13:36:43 GMT
From: "keith farmer;S10000" <[e-mail]>
Subject: Swift-Tuttle Comet a threat to earth?
Newsgroups: sci.astro,sci.space

In article <pad.720924805@probitas> [e-mail] (Paul A Daniels) writes:
>    Geologists belive that the earth originally had a super continent
>don't ask me to spell it's name. I'm just curious, could it have broken
>up due to a meteor stike?
>
>Paul.
>
If I remember correctly, Pangaea and Gwandonaland are two names fro the super-continent...

Keith

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

Date: 6 Nov 92 16:37:46 GMT
From: Dave Garnett <[e-mail]>
Subject: Swift-Tuttle Comet a threat to earth?
Newsgroups: sci.astro,sci.space

What is the state of the art in detecting and tracking
objects of this order of size ? Assuming that we have
a pretty good idea of the likely orbit, how far out
could we detect it - would we use radar or optical
means (or w.h.y.) ?

Dave Garnett

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

Date: 5 Nov 92 19:23:02 GMT
From: Bruce Watson <[e-mail]>
Subject: Swift Tuttle and the satellite belt
Newsgroups: sci.space

In article <[e-mail]| [e-mail] (Greg Jensenworth) writes:
|So, suppose P/Swift-Tuttle misses the earth, but is closer than the
|moon.  Will it basically erase all the satellites on that side of the
|earth?  There will be a lot of junk traveling along with the nucleus,
|I would think...
|
The vast majority of artificial earth satellites live within 3000 km
of the earth's surface, the remainder include the GPS sats in 12-hour
orbits, the Molniya which start out low (around 400 km) and rise
to 40000 km, the geostationary sats (at 40000 km) and very little else.
40000 km is 1/10th the distance to the moon, so if the comet is any
danger to the satellites is must go by at 40000 km or come closer
than 3000 km.

--
Bruce Watson (wats@scicom)  Tumbra, Zorkovick; Sparkula zoom krackadomando.

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

End of Space Digest Volume 15 : Issue 388
------------------------------