Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V16_0/V16NO017.ZIP/V16NO017

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Date: Fri,  8 Jan 93 05:04:38
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #017
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri,  8 Jan 93       Volume 16 : Issue 017

Today's Topics:
                             DC-Y funding
        HST Discovers Double Nucleus in Core of Active Galaxy
                      is the Lunar Society real?
                              man-rating
                     Moon Dust For Sale (2 msgs)
     Question:How Long Until Privately Funded Space Colonization
                         Question about SETI
           question on privately funded space colonization
                       Railgun in Southwest US
                  RTG's on the Lunar Module (2 msgs)
      Shuttle a research tool (was: Re: Let's be more specific)
         Who can launch antisats? (was Re: DoD launcher use)

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

Date: Thu, 7 Jan 1993 14:08:50 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: DC-Y funding
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:

>->(And if these incidental payloads were not subsidized, the market
>->might be even smaller.)

>-Not so. If NASA implements the voucher system authorized in last years
>-authorization bill they could launch more payloads for less cost.

>I was thinking of the commercial (rather than government) payload market.

That's the rub. The governemnt launches (some of which are commercial)
account for well over half the market. It it all swiched to commercial,
we wold see at least a 30% reduction in cost to orbit.

>The Shuttle has lots of "nooks and crannies" for small payloads, and if
>the government is using the Shuttle anyway for the large payloads and
>human-tended experiments, then there's very little marginal cost to the
>government in also using the Shuttle for small payloads

But at what cost? Providing these people subsidies to fly Shuttle only
kills alternatives like ISF and Commet. All we are doing is keeping
the expensive system and killing the cheaper alternatives. I submit
that this is a bad idea.

What's wrong with vouchers? That way the users are encouraged to use
the cheapest service available. Doint this will cut costs and allow
more payloads to fly. It will encourage the creation of cheaper
alternatives and help everybody.

>which need to be returned to Earth after several days in orbit),

Why do you assume that Shuttle is the one and only way to do that?
If your correct, then the voucher holders will pick Shuttle. If not,
then a market suddenly exists to provide these services.

>You seem to be implying that the market even for small payloads is almost
>exclusively government-funded - that the private sector for the most part
>just isn't interested in launches of small payloads - because if there were
>a private market, and if commercial launchers were cheaper to the customer
>even with the subsidized prices of GAS cans, etc. on the Shuttle, then the
>private customers would choose the private launchers even with the current
>setup.

Except that Shuttle distorts the market. It makes it seem much smaller
than it actually is. This slows or halts the competition which reduces
costs. Vouchers wold open the whole makret to competition.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------107 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Thu, 7 Jan 1993 17:12:00 GMT
From: Ron Baalke <[e-mail]>
Subject: HST Discovers Double Nucleus in Core of Active Galaxy
Newsgroups: sci.space,sci.astro

Paula Cleggett-Haleim
Headquarters, Washington, D.C.               January 7, 1993
(Phone:  [phone])

Jim Elliott
Goddard Space Flight Center, Greenbelt, Md.
(Phone:  [phone])

Ray Villard
Space Telescope Science Institute, Baltimore
(Phone:  [phone])

RELEASE:  93-006

HUBBLE  DISCOVERS A DOUBLE NUCLEUS IN CORE OF ACTIVE GALAXY

     Astronomers, using the Hubble Space Telescope, now
believe that a galaxy they have observed for a decade
actually is composed of two merged galaxies and that the
collision has provided new fuel for a massive black hole
which is spewing out a jet of gas and other matter 240,000
light-years long.

     The galaxy is Markarian 315 located about 500 million
light-years from Earth.  The collision and refueling theory
emerged after the Hubble Telescope revealed that the galaxy
has a double nucleus or two core-like regions.

     The brighter core-like region is believed to harbor the
massive black hole which accounts for the tremendous amounts
of energy produced by the galaxy.  The fainter nucleus is
considered to be the surviving core of a galaxy that recently
merged into Markarian 315.

     "The galaxy's active core presumably harbors a black
hole which has been re-fueled by the galactic collision,"
said Dr. Jack MacKenty, Assistant Scientist at the Space
Telescope Science Institute in Baltimore.

     "The Hubble images provide support for the theory that
the jet-like feature may be a 'tail' of gas stretched out by
tidal forces between the two galaxies as they interacted,"
explained Dr. MacKenty, Assistant Scientist at the Space
Telescope Science Institute.

     "The jet feature is most likely a remnant of a merger
between Markarian 315 and a smaller galaxy," said MacKenty.
This observation best explains the extraordinary 240,000-
light-year long jet-like feature of Markarian 315.

     An image of the core of Markarian 315, taken with the
Hubble Space Telescope's Wide Field and Planetary Camera
shows a second, fainter nucleus located approximately 6,000
light-years (or 2 arc seconds in angular separation) from the
galaxy's bright central nucleus.  One light-year equals
approximately 5.8 trillion miles (9.3 trillion km).

     Galaxy mergers may be one mechanism for driving gas deep
into the heart of a galaxy, astronomers believe.  This raw
material fuels massive black holes, theorized to be the
"central engines" in Seyfert galaxies and other active
galaxies.

     The Hubble Space Telescope's high spatial resolution
allows astronomers to probe the cores of Seyfert galaxies in
unprecedented detail.  In exposures taken with ground-based
telescopes, the companion nucleus is drowned out by the
brighter Seyfert nucleus.

     The report on this discovery is by Drs. John MacKenty
and Andrew Wilson of the Space Telescope Science Institute,
Baltimore; Richard Griffiths of The Johns Hopkins University,
Baltimore; and Susan Simkin of Michigan State University,
East Lansing.  The report was delivered at the 181st Meeting
of the American Astronomical Society meeting in Phoenix,
Ariz.

     The Hubble Space Telescope is a project of international
cooperation between NASA and the European Space Agency.

- end -


NOTE TO EDITORS:  A photograph to illustrate this story is
available by calling NASA's Broadcast and Imaging Branch on
202/358-1900.

             Color:   92-HC-733              B&W:   92-H-794
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Choose a job you love, and
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/  |_|/       |_____|/                     | a day in your life.

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

Date: Thu, 7 Jan 1993 12:10:11 MST
From: "Richard Schroeppel" <[e-mail]>
Subject: is the Lunar Society real?

Randall Tyers <tyersome@toxic> writes
>   Subject: Question:How Long Until Privately Funded Space Colonization
    In response to this question, a group called the Lunar Society appears
    to be interested funding space colonization.  I would like to know
    whether they are for real.  Does anyone know if this group is
    legitimate and whether they have any chance of reaching their stated
    goals?

and reprises the original LS announcement asking for support.

I sent them a $25 check in August (enough to get the newsletter), and
haven't heard a peep from them.  They haven't cashed the check though.
Perhaps they're just slow.

Rich Schroeppel  [e-mail]

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

Date: Thu, 7 Jan 1993 15:24:56 GMT
From: Dillon Pyron <[e-mail]>
Subject: man-rating
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] writes:
>>>There is no need to man rate. It adds cost but doesn't affect
>>>safety. If it where your money would buy the $70 million 98% safe
>>>Atlas or the $90 million 98% safe Atlas?
>>
>>YOU say there's no need to man-rate. The astronaut community and anyone who
>>goes up on it IS going to disagree with you.
>
>Depends on *who* goes up on it; sensible people will look at the reliability
>figures and conclude that man-rating decreases the chances of a successful
>flight (because it runs up the cost without increasing reliability).
>
>The astronaut community is less conservative, overall, than their official
>public image would have you think.  You'd have plenty of volunteers from
>there if the engineering looked sensible and the purposes looked worthwhile,
>even disregarding the number of qualified volunteers from elsewhere.

These are guys (mostly guys) have a professional career of flying aircraft
on/beyond the edges.  I worked at Edwards for a short while, and one AF
construction types repeated the morbid joke that they are always building new
roads there.  Why should "astronauts" suddenly develop a need for perceived
safety?

BTW, the STS is the safest transportation system we have, based on fatalities
per passenger mile.  But who would pay $1 billion apiece for a 747?  (Please
attach a smiley to the safety record).
>
>However, Doug's point is nevertheless valid, because the original context
>was official government projects... and it is official NASA dogma that
>man-rating is mandatory for such purposes.
 And we all know that a dog ma is a bitch  :-)
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |"Pacts with the devil are not legally
[e-mail]          |binding!"
PADI DM-54909                     |-Friar Tuck   _Robin Hood:The Hooded Man_

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

Date: Thu, 7 Jan 1993 15:04:25 GMT
From: Dillon Pyron <[e-mail]>
Subject: Moon Dust For Sale
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]>, [e-mail] (fred j mccall 575-3539) writes:
>In <[e-mail]> [e-mail] (Thomas E. Smith [LORAL]) writes:
>>I'm just guessing on my figures, but wasn't 500 lbs of moon rock and dust
>>brought back from the moon? And didn't the entire Moon program cost around
>>$67 billion? I think that puts the moon dust/rocks at about $134,000,000 a
>>pound! But as Ken says, it ain't fer sale by Nasa.
>
>Of course, the preceding reasoning assumes that the sole function of
>the entire Moon program was to produce those rocks as a product.  I
>think there was just a BIT more to it than that.  Using the same
>logic, one could say that we paid $67 billion to develop Tang.
>
For $67 billion, I would have thought they could have also freeze dried the
vodka :-).  (Has anyone tried the freeze dried beer from Japan.  It tastes like
hell until you are about four days out on the trail.)
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |"Pacts with the devil are not legally
[e-mail]          |binding!"
PADI DM-54909                     |-Friar Tuck   _Robin Hood:The Hooded Man_

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

Date: Thu, 7 Jan 1993 17:20:32 GMT
From: Bob Martino <[e-mail]>
Subject: Moon Dust For Sale
Newsgroups: sci.space,sci.astro,alt.sci.planetary

     A truly simple calculation.

     (A)  Determine the mass of all moon rocks recovered.  (use a
          REAL unit like kilograms, please)
     (B)  Determine the total cost of the Apollo program.  (Probably
          should include the cost of Gemini also)
     (C)  Divide (A) into (B) to arrive at the figure.

     Any questions?      :-)
_________________________________________________________________________
                                    | "...for since the creation of the
      - that Bob Martino guy -      |  world His invisible attributes,
 [e-mail] |  His eternal power and divine
                                    |  nature, have been clearly seen,
   God invented science.  so there. |  being understood through what
       ^^^^^^^^                     |  has been made        -Romans 1:20
-------------------------------------------------------------------------
 "That's the whole problem with science.  You've got a bunch of
  empiricists trying to describe things of unimaginable wonder."
                                                  -Calvin

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

Date: Wed, 6 Jan 1993 23:54:38 GMT
From: Brian Rauchfuss <[e-mail]>
Subject: Question:How Long Until Privately Funded Space Colonization
Newsgroups: sci.space

In sci.space, [e-mail] (Chris Marriott) writes:

> The "space elevator" - basically dropping a cable from a geosynchronous
> satellite to Earth (and, of course, another one upwards so the centre of
> mass stays still) is probably the most *lethal* device one might conceive
> of building!  Imagine the cable breaks near the mid-point.  You have 38000km
> of cable falling to earth at *orbital* velocities, enough to wrap itself
> around the entire equator of the planet!  Go figure out the kinetic energy

> involved.  How much ocean would it vaporize?  Massive medium-term climatic
> changes at best - "nuclear winter" scenarios.  A new Ice Age a distinct
> possibility.

Most of the cable would vaporize long before it could do any damage.  The
cable doesn't mass enough to survive reentry.  That is why we can have so many
meteors hitting earth at orbital velocities and not even notice.

Of course the first few miles of it would survive, which would be an
impressive fall (!), but probably not disasterous if it lands in the ocean.

----------------------------------------------------------------------
Brian Rauchfuss (Smokefoot)  "... the world could change in the blink
[e-mail]           of an eye."

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

Date: Thu, 07 Jan 93 15:46:31 MET
From: [e-mail]
Subject: Question about SETI

From "New Scientist", 12 December 1992:

WHEN WILL EARTHLINGS SEE THE LIGHT?

Nigel Henbest believes that NASA's search for ET is on the wrong wavelength

  Amid much hullabaloo, the US space agency NASA has just embarked on a
mission to search out extraterrestrial beings, wherever they may be
in the Galaxy. Over the next 10 years, American scientists at giant
radiotelescopes all over the world will scan the skies for radio messages
from ET. But why does their search for extraterrestrial intelligence
(SETI) involve looking for radio waves?

  Put that question to most NASA scientists, and you get a stock answer.
Because, they explain, radio waves can travel thousands of light years
through the dust of interstellar space. And, natural sources of radiation
happen to be "quietest" at short radio wavelength, so we get less hiss on
the line. Even if ET is not broadcasting intentionally to space, we can
try to eavesdrop on his - or her - television broadcasts.

  There are, of course, many other possible wavelengths that extra-
terrestrials could use. Having spent the past few months making a
television program on SETI, I have found NASA's stock answer profoundly
dissatisfying: why, I still ask, is NASA searching for radio waves?

  The answer, I believe, is simply that the idea of interstellar
communication began in the 1950s when radio technology was a white-hot
subject. Powerful radio telescopes were receiving faint whispers from
galaxies so far off that they were invisible to even the mightiest
optical telescopes. Human beings were transmitting radio waves ever
more powerfully. The strongest broadcasters were the television stations
disseminating 'I Love Lucy' to millions of fans, and the military radars
on the lookout for enemy missiles about to rain down from the skies.
What was more natural, than to imagine a sensitive radio telescope
tuning into radio transmissions of another civilisation?

  But another civilisation "out there" is likely to be thousands of years
more advanced than us, if not millions. It's very unlikely that they
would think the same way that we did in the 1950s. Indeed, our own
situation has changed in only 35 years.

  Take the point about eavesdropping. An advanced planet is likely to be
a radio-quiet zone. Even in the past few years, our planet has become a
quieter place. For broadcasters, every watt of radio power that leaks
away into space is a watt of power wasted. Television is increasingly
being transmitted by cable or by satellites that beam only onto a small
region of the Earth, with no wastage into space. And a civilisation
that survives past the stage of "mutually assured destruction"
presumably has no need for powerful military radars.

  And if you want to send an interstellar message, radio, as a medium,
has one overriding drawback. Its frequencies are so low that you can
transmit information only at quite a slow rate. So let me rewrite the
history books a bit. Suppose the idea of SETI had come along a decade
later than it did. The leading edge of technology is now the laser.
Scientists regard the laser as the ideal mean of communication.

  Hold on, astronomers may say. The dust in interstellar space will
absorb your laser beams as surely as earthly clouds hide the Sun. That's
true for long distances - but don't forget that enough light gets through
space for us to see thousands of stars with the naked eye, and millions
with an optical telescope. And if we tune our laser to a wavelength
into the infrared, it can slice through dust clouds as easily as radio.

  But surely a laser's light would be overwhelmed by the brilliance of
starlight - especially by the light from the sun of the civilisation
sending the message? In fact, that is not a problem either. A laser
crams all its energy into just one specific wavelength. If you are
receiving the signal, you split the light into a spectrum. Now stretch
out the spectrum. The whitish light from the star is diluted more and
more as it is stretched, while the single narrow spectral line from the
laser keeps its intensity. With enough stretching of the spectrum, the
laser will eventually stand out clearly.

  Laser communication has two great advantages. Due to its high
frequency, you can send a lot of information very quickly. Laser beams
are also narrow: whereas a radio signal spreads out as it travels
through space, diluting its power all the way, you can use comparatively
little power with a laser because it does not spread out.

  For these reasons, NASA spacecraft engineers are planning to use
lasers to communicate on its future missions to the outer parts of the
Solar System. Lasers are small, too, so spacecraft will not need large
radio antennas to communicate with Earth. This will avoid some
embarrassing debacles: the Galileo spacecraft, for example, on its way
to Jupiter, is gagged because its umbrella-like antenna has not
unfurled.

  Next month, in Los Angeles, the international Society for Optical
Engineering (SPIE) is holding a symposium on laser communications in
space. Here, ironically, communications specialists from NASA will
discuss laser links with spacecraft, while their SETI colleagues just
up the road in Pasadena in the Jet Propulsion Laboratory - who are
supposed second-guessing the thoughts of far more advanced
civilisations - are pursuing the dinosaur route of radio communiaction.

  Still, I am delighted to see that one session at the SPIE meeting is
devoted to "SETI in the optical spectrum". Stuart Kingsley, a pioneer
of optical SETI who runs an optoelectronics company in Colombus, Ohio,
argues that an optical search for ET would be cheap as well as effective.
It need not take optical telescopes away from their scheduled night-time
task, because the laser power in a narrow band would stand out even
above the brightness of daylight, if you stretch the spectrum enough.

  The optical SETI symposium is being opened by Arthur C. Clarke - and
that, I reckon, is a sure sign of what the future holds in store.

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

Date: 7 Jan 93 14:09:54 GMT
From: Herman Rubin <[e-mail]>
Subject: question on privately funded space colonization
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:

>-From: [e-mail] (Herman Rubin)
>-Subject: Re: Question:How Long Until Privately Funded Space Colonization



>->In <[e-mail]> [e-mail] (Randy Burns) writes:
>->>What are the current estimates of folks in this newsgroup of how long it
>->>will be until the world starts to see privately funded space colonization?

>-Can one
>-reasonably expect people to do things when the government can step
>-in at any time and say no, or say that what you have done belongs
>-to it?

>If it's the principle of eminent domain that you're worried about, then
>yes, that could theoretically happen. But the same applies to activities
>on the Earth. Does it make sense to refuse to buy a house or a car because
>in principle the government could take it away? In practice, most people
>don't have their houses or cars taken by the government - the political
>cost of doing so is high, serving to act at least as a partial check on
>the use of eminent domain. In fact, government seizure of a privately built
>lunar base could well be harder than (for instance) taking property on
>the Earth for a road or a landfill - not only is it much more "visible",
>but the US government hasn't claimed that the moon is part of its territory.

My concern has nothing to do with the principle of eminent domain.  It also
has nothing to do with claims about ownership of the moon.

Consider the possible scenario:  An American organization raises enough
money to produce and operate a space station, acquires launching rights
in Tanzania, acquires the necessary equipment, and then existing law is
invoked to tell the organization that they cannot do it.  I believe that
this law could be invoked if Americans even participate in a foreign
organization.

Or the bureaucrats decide that the presence of a lunar colony would
"not be in the national interest," and invokes RICO (it sure is that
broad) to seize at least any American assets of the organization.
I doubt that the government of any industrial nation wants man in
space unless it is strictly under its control, or at least under the
control of those who would stifle mankind.

--
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399
Phone: [phone]
[e-mail] (Internet, bitnet)
{purdue,pur-ee}!snap.stat!hrubin(UUCP)

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

Date: Thu, 7 Jan 93 10:34:57 CST
From: ssi![e-mail] (Louis F. Adornato)
Subject: Railgun in Southwest US

uunet!eros.calpoly.edu!jgreen writes:
> I've heard a rumor that some organization (SSI?) has actually
                                             ^^^^<--- (see signature line)
> built a large railgun somewhere in the SW USA.  It's apparently
> supposed to be big enough to put small payloads (>5 kg) into
> orbit, though I don't know if they've done that yet.
>
> Is this a rumor or is there some truth to it?

I can state with some certainty that it wasn't us.

Seriously, I saw a public demonstration of a rail gun on the tube a few
years back, but it was intended as an onorbit weapon for SDIO (this
whas when they where fighting their "No, we're really not a pipe dream"
funding battle).  I think this was in So. California, which is
certainly SW USA.  As I recall, it fired something about the size and
shape of a hockey puck (there's that Canadian influence again, eh
Henry?).  I haven't heard anything about a ground based version.

Personally, I don't know that a railgun is going to be worth much for
anything other than ASAT and ABM applications.  The problem is that a
ground launched body can't attain orbit (at least, not an orbit that
doesn't intersect the surface) without a circularizing burn at
periapsis.  This means that you have to carry propulsion (motor and
fuel), GNC hardware (star trackers or a gyro/accelerometer platform,
momentum wheels or an RCS, guidance computer and control hardware),
power and cooling, a shroud capable of protecting the whole shebang
when it exits the launcher in sea level air at better than 17,000 mph
(orbital velocity at 150 mi), aerosurfaces to prevent tumbling, and
probably active control of same, and still retain enough mass
capability for a payload.

On the other hand, if all you want to do is intercept incomming
missiles, you can scrap most of this except the shroud and the
aerosurfaces.  Approriate sensor technology in the nose and a
"bang-bang" control system for terminal homing, and you have enough
payload space for a fuze and some plastique (although the entire
vehicle becomes a warhead at the kind of intercept speeds involved).
Of course, a rail launcher certainly wouldn't be portable, and the
power generating equipment (if not the rail itself) would be pretty
noticeable from orbit.  Might as well put up a big sign that reads
"Please Nuke Me".

Seems to me that something like Pegasus is a better investment for both
types of applications in this payload mass category.

Lou Adornato                 |    "Sure, the cow may have jumped over the
Supercomputer Systems, Inc   |      moon, but she burned up on reentry"
Eau Claire, WI               | The secretary (and the rest of the company)
uunet!ssi!lfa or [e-mail] | have disavowed any knowledge of my actions.

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

Date: 7 Jan 93 14:45:16 GMT
From: Dave Garnett <[e-mail]>
Subject: RTG's on the Lunar Module
Newsgroups: sci.space

Peering at a cut-away drawing of the Lunar Module the other day
I noticed what appears to be a Radioisotope Thermal Generator
mounted on the outside low down.

Was this intended to power some experiment - I don't think
that they generate very much power (order 80 watts ?)

What are the radiation hazards (to the crew) associated
with such a thing, as I understand that they comprise an
unshielded lump of plutonium ?

Dave

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

Date: 7 Jan 93 16:26:06 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: RTG's on the Lunar Module
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Dave Garnett) writes:
> Peering at a cut-away drawing of the Lunar Module the other day
> I noticed what appears to be a Radioisotope Thermal Generator
> mounted on the outside low down.
>
> Was this intended to power some experiment - I don't think
> that they generate very much power (order 80 watts ?)

Yup.  They powered the Apollo Lunar Science Experiment Packages
(ALSEP), various experiments left behind on the Moon, such as heat
flow measurements and seismographs.

> What are the radiation hazards (to the crew) associated
> with such a thing, as I understand that they comprise an
> unshielded lump of plutonium ?

Fairly negligible.  Escaping radiation is probably some gamma rays,
but the bulk of the radiation is alpha particles which are stopped
very quickly in the casing of the RTG.  The RTGs were probably fairly
far from the astronauts with considerable material intervening for
shielding.  With care, handling them to set up the experiments was
probably not very dangerous.  My guess is they are really plutonium
dioxide, which is chemically quite inert (insoluble in water and very
weakly soluble in acid, so pretty resistant to corrosion).  Anybody
got more facts?

For lots more detail on plutonium see the references given in the
sci.space FAQ.  They deal mostly with the Galileo and Ulysses RTGs but
there is a good general rundown on Pu toxicity: "Hazards from
Plutonium Toxicity", by Bernard L. Cohen, *Health Physics*, Vol 32
(may) 1977, page 359-379.

A relevant quote from the FAQ:

   Two interesting data points are (1) The May 1968 loss of two SNAP
   19B2 RTGs, which landed intact in the Pacific Ocean after a Nimbus
   B weather satellite failed to reach orbit. The fuel was recovered
   after 5 months with no release of plutonium. (2) In April 1970, the
   Apollo 13 lunar module reentered the atmosphere and its SNAP 27 RTG
   heat source, which was jettisoned, fell intact into the 20,000 feet
   deep Tonga Trench in the Pacific Ocean. The corrosion resistant
   materials of the RTG are expected to prevent release of the fuel
   for a period of time equal to 10 half-lives of the Pu-238 fuel or
   about 870 years.

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

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

Date: 7 Jan 93 16:16:38 GMT
From: Francois Yergeau <[e-mail]>
Subject: Shuttle a research tool (was: Re: Let's be more specific)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Francois Yergeau) writes:
>
>>But the airlines do not contract out their operations.  They procure
>>planes, and fly them, just like NASA buys shuttles and operates them.
>>It's certainly proper, legal, and it's not clear to me that doing
>>otherwise would be beneficial.
>
>Commercial launch services cost the government 30% to 50% less then when
>government buys and operates the system itself. It is therefore very clear
>that doing otherwise would be very beneficial.

This has never been demonstrated for manned spaceflight, but may very
well be.  DC will be a very good occasion to try out, if Murphy's law
can be circumvented.  But didn't I read not long ago that MacDD would not operate DC?  Who would?

--
Francois Yergeau ([e-mail]) |  De gustibus et coloribus
Centre d'Optique, Photonique et Laser    |  non disputandum
Departement de Physique                  |          -proverbe scolastique
Universite Laval, Ste-Foy, QC, Canada    |

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

Date: Thu, 07 Jan 93 17:24:05 GMT
From: Doug Mohney <[e-mail]>
Subject: Who can launch antisats? (was Re: DoD launcher use)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Josh 'K' Hopkins) writes:

>>It is likely we have a quick-launch replacement capability, either through
>>air breathing mysterious aircraft or (more likely) derivative ballistic missile
>>capability, on land and at sea.
>
>Could you please cite a shread of evidence that such a system is operational?
>Stipulating for a moment that the capability exists, please explain how many
>ground based backups there are for KH-12s or how long it takes to replace them.
>Quick launch capability is after all quite useless without something to launch.

Josh, Aviation Week has published material on the possible existing
air-breathing quick-launch capability. It is also known some Minuteman
missiles are not loaded with nuclear weapons, but comm relays and such.

As for the exact number of ready-launch backups, what their capabilities
are, and so forth, it falls under "black" programs and you won't find it
published on the front page of the Washington Post.

Since the ex-Sovs demonstrated a capability to hit targets in orbit, it HAS
been a worry of warplanners and certain contingencies have been planned for.

>>It is unlikely the attacking third-world country would have an equalivent
>>replacement capability for whatever assets it has.
>
>If you're assuming the attacker is a third world country than you seem to be
>ignoring the possibility that it doesn't have significant assests worth
>worrying
>about.  That doesn't mean that they wouldn't love knocking ours out.

Satellite-based communications and imaging are both within in the grasp of any
third world country which can put up an ASAT to successfully attack orbital
assets.

>>>That didn't stop Saddam Hussein from invading Kuwait.
>
>>Sure it didn't. However, the UN voted to remove Iraqi troops by the use of
>>force and thereby did so accordingly. Had Iraqi troops seized anything less
>>than Kuwait City, or removed themselves from Kuwait City without committing
>>anything more than token atrocities, Iraq would not be divided into three parts
>>today.
>
>And the threat of that didn't stop Saddam Hussein from invading either.  Keep
>in mind that attackers frequently think along different lines than their
>enemies expect them to.

What threat? Hussein was not THREATENED with anything until after he took over
Kuwait and the stories of atrocities came out.

Had Mr. Hussein limited himself to redrawing the borders of Kuwait and not
invaded Kuwait City; he wouldn't be in the trouble he (still) is in today.

The original point is "World Opinion DOES count." Iraq would not be abused if
it behaved.

                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

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End of Space Digest Volume 16 : Issue 017
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