Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_2/v16no267.txt

Internet Message Format | 1993-07-13 | 29KB

Date: Thu,  4 Mar 93 05:57:51
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #267
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  4 Mar 93       Volume 16 : Issue 267

Today's Topics:
                                <None>
              Alternative space station design (2 msgs)
                      A response from Anonymous
                           Aurora (rumors)
                         Battery help needed!
                                Blimps
                          Followon missions
                 I have a dream! People into Space..
                    Looking for help with Iridium
                      Mars exploration (4 msgs)
                    Opening up Space to everyone!
            Sexy batteries (was Re: Battery help needed!)
                           Space Scientist
                         Stupid Fred Question
                      Water resupply for SSF (?)

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Tue, 2 Mar 1993 19:32:59 GMT
From: [e-mail]
Subject: <None>
Newsgroups: sci.space

In article <[e-mail]>,
[e-mail] (Richard A. Schumacher) writes:

> Most supernovae leave some kind of remnant. (In fact is there any
> known way of blowing up a star and leaving no compact object behind?)

The detonation and deflagration models for type I SNe postulate complete
destruction of the progenitor leaving no compact object behind.

-Bill Gawne,  Space Telescope Science Institute

 "Forgive him, he is a barbarian, who thinks the customs of his tribe
  are the laws of the universe."                       - G. J. Caesar

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

Date: 2 Mar 93 21:32:10 GMT
From: Doug Mohney <[e-mail]>
Subject: Alternative space station design
Newsgroups: sci.space

In article <[e-mail]>, Dr. Norman J. LaFave <[e-mail]> writes:
>* Primary power source---NOT solar arrays!
>
>  RTG pallet---known technology...not subject to shadowing problems...
>        eliminates primary plume impingement problems....eliminates
>largest
>        flexibility problems, both control and structural....proven
>safety.

Politically incorrect.  RTGs would be a no-go. Bad enough to have the Christic
(?) Institute bitching about departing probes with RTGs.

You'd get the double wammie:  How much mass are you talking about for the power
needs of the station?  Now, take that amount of Pu-238(?) and plug it into
the following press release:

    GREENPEACE ALERT!!!!!

    NASA proposes putting over <large number> kilos of high toxic
    plutonium into orbit around our planet.

    (reference to Challenger disaster, Skylab reentry, and other thing)

    (Quote from Sherzer about how inept NASA is and how they would
    be expected to lose at least one payload of RTGs)

    WRITE YOUR CONGRESSMAN TODAY TO SAVE THE EARTH FROM DESTRUCTION!

Now, you may protest all you want, but this is how they'd play it....



    Software engineering? That's like military intelligence, isn't it?
  -- >                  [e-mail]                        < --

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

Date: 2 Mar 93 20:34:00 GMT
From: "Dr. Norman J. LaFave" <[e-mail]>
Subject: Alternative space station design
Newsgroups: sci.space

> [e-mail] (Edward Dansavage Wright) writes...
> >
> >Info request to the net....
> >
> >I am interested in space station designs not based on the
> >"power tower" concept as was/is Freedom.  I am interested in
> >alternative designs such as inflatable structures, geodesic
> >dome configurations etc.  Could someone please provide a starting
> >place to look for this information?  Is there a particular NASA
> >installation I should contact?

Well, I can discuss a design that some colleagues and I worked on
and presented during the last redesign. We believe it to be a superior
design, but we have doubts about whether it will be accepted for the
upcoming redesign. However, we are hoping that aspects of the
design will be considered.

Features:

* Alternative modular structures (NO TRUSS):
   Either:

        Modular self-packing building blocks (Truncated Octahedra) as
        the basic building blocks (fully enclosed, but with removable wall
        plates and edge rib elements). This type of block would allow the
        construction of an arbitrarily large open space (pack the blocks,
        pressurize them, and remove interior walls and ribs).

   Or:

        Cylinders and node modular building blocks based on the current
        Lab/Hab design.

  Either way, the modular concept has alot to say for itself in
flexibility
  of configuration and adaptibility to changing requirements. Furthermore,
  both of these designs are free of the troublesome flexibility inherent
  in the truss and have much more usable pressurized space available.

* Each module, when it is brought up on the shuttle, is equipped with
   its own temporary, modular control and
   maneuvering system (flight control, guidance,  and nav computers,
  jets) which allow it to "fly itself" out of the shuttle bay and "dock"
  with the station. The astronauts then make the "dock" semi-permanent.
  The computers can then be removed from the module and the jets can
  be integrated with the station's over-all flight control and reboost
system.

   This has several advantages: 1.) It removes the most troublesome
aspects
   of using the orbiter in the construction of the station (berthing,
plume
   impingement, etc) and replaces it with simple docking procedures, 2.)
It
  allows reconfiguration of the station at any time by undocking and
flying
  a module to a new docking site, 3.) It allows the station to be "pay as
you go"
  because you are not so locked into one configuration.

As an alternative, a "tug boat" could be designed as part of the station
to
ferry the modules in and dock them.

* Primary power source---NOT solar arrays!

  RTG pallet---known technology...not subject to shadowing problems...
        eliminates primary plume impingement problems....eliminates
largest
        flexibility problems, both control and structural....proven
safety.

  Secondary source: Thermal gradient power generation---This is an idea
  we are toying with. The idea is simple. Use the huge temperature
gradients
  that can be generated between sunlit and shadowed plates to generate
  power. This is much like the concept which was studied to generate power
  using the thermal gradient between the ocean's surface and the ocean
  depths.

* Passive flight control---a return to the "Power Tower".

The present design is one of the few vehicles I can think of that goes
out of its way to fight its natural environment. Think of a ship. Ships
have rudders to use the water for steering, sails to use the wind for
propulsion (or screws), and a keel to use gravity gradients and the water
for stability. The current station's proposed orientation is analogous to
forcing a ship to sail on its side. The aero forces act to turn the
station
with the truss pointing into the wind, and the gravity gradient forces act
to tip the station with the truss pointing up. Flying the station in the
proposed orientation requires alot of active flight control in the guise
of CMGs and RCS jet firings.

We propose returning to the power tower orientation with a "rudder". This
allows the use of aero and grav gradients to achieve 3-axis passive
stabilization and minimize RCS fuel usage.

This isn't the most lucid description of this I have ever given, but
"wadda ya think?"

Norman

Dr. Norman J. LaFave
Senior Engineer
Lockheed Engineering and Sciences Company




When the going gets weird, the weird turn pro
                               Hunter Thompson

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

Date: Tue, 02 Mar 93 20:04:27 CET
From: Alexander EICHENER <[e-mail]>
Subject: A response from Anonymous
Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space,sci.astro

In article <[e-mail]>
[e-mail] (Dave Ratcliffe) writes:

>One thing seems to be getting lost in all the rhetoric. Anonymous
>postings DO have their place, but not in groups like sci.space or any
>other similar groups. Examples of where they might well be acceptable
>have been posted already several times. Why doesn't anyone want to
>discuss this facet?

Grin. Okay, I shall bite. Even though we would argue otherwise, I can
easily agree with you that it is hard to see why a posting in sci.astro
or sci.space should be anonymous. However, there is one major attitude
difference between us. You say: "I can't see any good reason for it. Thus,
it should be forbidden. Where I acknowledge a legitimate reason, I shall
allow it".

And I gently oppose: "If someone has to say something meaningful,
yet wishes to remain anonymous, it doesn't hurt me. If I am interested,
I shall read and judge upon content. If I despise anonymous wimps ;-),
I skip the stuff. But I won't force my attitude upon others' freedom.
In case of abuse (people posting unrelated stuff to a newsgroup that
doesn't want to hear about Serbian crimes, e.g. in soc.culture.german),
the server admin should deal with the abuse."

P.S.: Even though Tarl asserts the contrary, Julf (Johan Helsingius) *is*
dealing with abuse and behaves very considerately and reasonably here.

Alexander Eichener <[e-mail]>

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

Date: 2 Mar 93 21:51:06 GMT
From: Dillon Pyron <[e-mail]>
Subject: Aurora (rumors)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Dean Adams) writes:
>[e-mail] (Dillon Pyron) writes:
> >But the SR-71 is a "hype"rsonic aircraft.
>The Blackbird flies at Mach 3-3.5, and "hypersonic" starts at Mach 5.

Dean!  You missed the sarcasim points!  "Hype"rsonic.
>
> >By flying at FL 850, the intended never heard a pop, nevermind a boom.
>Right.
>
> >I would be sorely disappointed to learn the the Aurora was anything
> >less than 100,000 ft (32000 m) and Mach 3.5.
>Make that Mach 6.

Sometimes my brain just quits early.
>
> >Not that we will learn any of that this century  :-)
>We'll see...(or not).
>
> >The booms LA hears, assuming they come from the Aurora, are due to a
> >Mach 1 aircraft coming home at about 25,000 ft.
>Probably a little higher and faster than that.
>
> >Consider how many approach options there are.
>Apparently there must not always be that many options, otherwise
>they would never have been bringing in in over L.A. so often.

Do we really know how often that was?  Every flight?  Every 10th, 100th,
1000th (right)?
>
> >I'll bet we don't hear many more.
>Why?  Not even the USGS reports stopped them before.
>
> >Finally, SSR is just not an effective surveillence tool.
>
>Well, DoD/NRO/CIA/etc. do not agree with you, since radar imaging has
>been a significant part of reconnaissance systems for decades.  There is
>a LONG list of aircraft which carry "SSR" type equipment, and there are
>currently TWO Lacrosse radar imaging satellites in orbit which cost
>Billions of dollars to develop and launch.  Somebody must think it is
>"effective".  :->
>
> >I might use it to look for the "Lost City of Zur", but
> >not for the "Lost Scuds of Saddam".
>
>Once again that is not the case.  Perhaps the #1 system that DoD wants
>to use for that very role is the new E-8 J-STARS, which stands for Joint
>Surveillance Target Attack Radar.  These aircraft carry SAR and Doppler
>radar systems for locating mobile ground targets such as Scud missile
>launchers...

If I may clarify, SSR, by itself, has not been useful.  Combined with other
inputs, it becomes part of a powerful synergism.  But, my understanding of SSR
(note by my sig that I am now "out of my league") is that it takes multiple
images to produce truly useful information.

More to the point, why spend billions on a single sensor platform?  That would
be like taking only Ektachrome 64 to DisneyWorld!

But, point well taken.
>
--
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)     |No people gave up their rights all at once.
[e-mail]          |Preserve the Bill of Rights.
PADI DM-54909                     |Protect the Second Amendment.

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

Date: Tue, 2 Mar 1993 19:30:59 GMT
From: "Robert F. Drury" <[e-mail]>
Subject: Battery help needed!
Newsgroups: sci.space

In article <1n02n5$[e-mail]>, [e-mail] (Chad Barret
Wemyss) wrote:
>
> In article <[e-mail]> [e-mail] (Henry Spencer) writes:
> >
> >I think I'd look into the sexier battery technologies, like nickel-hydrogen
> >or silver-zinc, first.
> >--
>
> And just how does one decide which batteries are "sexy"  :-)
>
> Chad Wemyss
> Worcester Polytechnic Institute

It's personal--which ones do you get a charge from?

Standard Disclaimer--My opinions are my own, and do not represent those of
my employer.
R.F.Drury
Du Pont Electronics
Internet [e-mail]

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

Date: Tue, 2 Mar 1993 17:44:07 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Blimps
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Josh Hopkins) writes:
>It would certianly be possible to actively heat the lifting gas. However, given
>that Mars has an atmosphere of CO2 and probably has plenty of native Hydrogen
>available for use I don't forsee a real need for active heating.  Passive lift
>should be just fine thank you.

Given that a blimp flies by displacement bouyancy, and given the low
density of Mars' atmosphere, active heating could be very valuable
in increasing the lift capacity of a Mars blimp. Even with hydrogen
as the displacement gas, you don't get a lot of lift. Therefore the
structural mass and payload of the blimp are extremely limited. If
you can heat the hydrogen, according to PV=nRT your displacement,
and hence your lifting capacity, increases in direct proportion to
the displacement gas temperature. Raise the gas temperature to 200C
and you would almost double the lifting capacity of the blimp over
that of an unheated system.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 2 Mar 1993 15:59:59 -0500
From: Matthew DeLuca <[e-mail]>
Subject: Followon missions
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:

>>Galileo and Magellan *are* followup missions, to the Pioneer and Voyager
>>series of probes.  For myself, I'd like to see what Galileo discovers before
>>trying to design a followup to it; there's no telling what we may want...

>Nonsense; there is considerable telling what we may want.

I suspect we have a semantic difference here.  A 'followup' mission implies
that it is building on what was learned from previous missions.  What you are
suggesting are missions that happen to follow in time.  Certainly a good idea,
but not exactly the same.
--
Matthew DeLuca
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp:      ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!matthew
Internet: [e-mail]

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

Date: 2 Mar 93 22:02:39 GMT
From: "Brian A.Laxson" <[e-mail]>
Subject: I have a dream! People into Space..
Newsgroups: sci.space

    International involvement would also help get people into space.
Many conutries can accomplish more together, just like more people can.
The international aspect would make it likely to accomplish some important
goals even if the main objective fails, particularly increase involvement
of people in space.

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

Date: 2 Mar 93 21:33:13 GMT
From: Dillon Pyron <[e-mail]>
Subject: Looking for help with Iridium
Newsgroups: sci.space

In article <[e-mail]>, Katy Root <Katy [e-mail]> writes:
>I am looking for background information on Motorola's telecommunications
>satellite project, Iridium.  I am looking for either information or where
>I can get information.  I am wanting to find out the benefits the
>satellites will offer to different groups of people and if there are any
>negatives, what they are.

I tried to reply by mail, but got bounced.

Katy, I have an article published in _Ocean Voyager_ on Iridium.  Send me your
address if you would like a copy.
>
--
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)     |No people gave up their rights all at once.
[e-mail]          |Preserve the Bill of Rights.
PADI DM-54909                     |Protect the Second Amendment.

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

Date: Tue, 2 Mar 1993 18:00:48 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Mars exploration
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Joe Chum) writes:
>In the  PBS series "Space Age", the first episode was devoted to Mars and
>the future plan to explore.  One  of the topic most interesting is the
>part  where divers were simulated by an underwater vehicle; they wore a
>helmet which they could see the vehicle with a camera attach to it.  The
>feeling described  is really great.  They  want the human mind to explore
>the terrain of Mars first before a man actually land there.   By using
>Virtual Reality, the astronaunt can feel what's it like on the surface of
>the planet without really being there.  This idea is so marvelous.  Why
>didn't they use it in the moon first.  I like to hear more comments about
>this hopefully.  So, if you great scientists out there can please spare
>a knowledge to the little curious one here.

In 1969 no one had even heard of VR telepresence. We still don't do it
very well. One of the larger problems even today is dealing with the
time lag for feedback. Round trip speed of light time to the Moon is
on the order of 2.5 seconds, it's over 4 minutes round trip to Mars
at closest approach. Decoupling your movement commands with your
perceptions by such a temporal displacement makes a mockery of
telepresence. A combination of the ever mythical AI and computer
simulation is usually envoked to get around this temporal barrier.
But with the higher risks to the mission such simulation of reality
entails, and the high cost of *any* mission to another planet, VR
telepresence seems unlikely to play a major role in forthcoming
missions.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 2 Mar 93 22:56:46 GMT
From: Timothy Banks <[e-mail]>
Subject: Mars exploration
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>In 1969 no one had even heard of VR telepresence. We still don't do it
>very well. One of the larger problems even today is dealing with the
>time lag for feedback. Round trip speed of light time to the Moon is
>on the order of 2.5 seconds

    Unfortunately I don't have a reference handy, but wasn't the
    Lunikhod (spelling?) remotely controlled?

--
  Timothy Banks, Physics Department, Victoria University of Wellington, NZ.
       bankst@kauri|rata|matai.vuw.ac.nz, [e-mail].
    "He's dead, Jim!" "OK, you take the tricorder, I'll take the wallet!"

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

Date: 2 Mar 1993 20:22:51 GMT
From: Jon Leech <[e-mail]>
Subject: Mars exploration
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Gary Coffman) writes:
|> In 1969 no one had even heard of VR telepresence.

    Beg to differ. Ivan Sutherland defined VR in a 1965 paper ("The Ultimate
Display"). The hardware wasn't very capable by today's standards. But like
most stuff in computer graphics, the seminal work is a lot older than people
usually think.

    I have around somewhere - can't find it at the moment - a paper by
someone at NASA Ames (Ellis comes to mind). It in part describes a
non-computerized form of immersive VR which involved pasting lunar
photographs to the inside of a dome and putting your head in it. I believe
this was done back during Surveyor.

    So people had thought of it before 1969, impractical though it might
still be.

    Jon ([e-mail])
    __@/

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

Date: Tue, 2 Mar 1993 20:43:45 GMT
From: [e-mail]
Subject: Mars exploration
Newsgroups: sci.space

In article <[e-mail]>, [e-mail]
(Joe Chum) writes:
> By using
> Virtual Reality, the astronaunt can feel what's it like on the surface of
> the planet without really being there.  This idea is so marvelous.  Why
> didn't they use it in the moon first.

I'm reminded of Heinlein's story of the young astronomer from UCSC who
asked him, "Why didn't you just use a computer?" after hearing the story
about how Robert and Virginia spent a week solving the elliptical
integrals for an asteroid intercept using yards of butcher paper and
slide rules in, I think, 1948.

The answer in both cases is essentially the same.  It's related to the
reason my '66 Fairlane didn't have electronic fuel injection.

-Bill Gawne,  Space Telescope Science Institute

 "Forgive him, he is a barbarian, who thinks the customs of his tribe
  are the laws of the universe."                       - G. J. Caesar

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

Date: Tue, 2 Mar 1993 17:52:07 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Opening up Space to everyone!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Simon E. Booth) writes:
>>In article <[e-mail]> [e-mail] (Marvin Batty) writes:
>>>
>>>With equal opportunities legislation, coupled to a good standard of medical
>>>support (not unlike standard life-support!) the presence of disabled people
>>>in space seems a real possibility. There really isn't any need that I can see
>
>I had been wondering the same thing myself.  Due to a back problem I have
>difficulty standing or walking more than 30 seconds at a time.
>
>This makes getting around under normal one-g difficult, to say the least.
>
>Theoretically, would this make adapting to zero-g easier?  I know the
>multiple g's of a launch would probably be a problem, so this is probably
>only a thought-exercise at best.  Still, for someone has has problems under
>normal gravity, would microgravity eliminate those problems or is there
>something I'm missing in this theory.

Unfortunately the back is more than just a support structure against
gravity. It acts as lever or anchor for many muscular exertions that
occur regardless of gravity. Since mass, and inertia, don't decline
in micro-g, you still have need for muscular exertion to get work
done. The documented calcium loss in micro-g might even aggravate an
already weakened skeletal condition.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 2 Mar 93 11:06:54 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Sexy batteries (was Re: Battery help needed!)
Newsgroups: sci.space,sci.electronics,sci.aeronautics,sci.chem,sci.engr

In article <1n02n5$[e-mail]>, [e-mail] (Chad Barret Wemyss) writes:
> In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>
>>I think I'd look into the sexier battery technologies, like nickel-hydrogen
>>or silver-zinc, first.
>>--
>
> And just how does one decide which batteries are "sexy"  :-)

On 9-volts, some people touch the contacts with their tongues...

Bill Higgins                           | "I shop at the Bob and Ray
Fermi National Accelerator Laboratory  | Giant Overstocked Surplus
Bitnet:           [e-mail]  | Warehouse in one convenient
Internet:       [e-mail]  | location and save money besides
SPAN/Hepnet:           43011::HIGGINS  | being open every evening until 9."

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

Date: 2 Mar 93 17:46:28 GMT
From: CLAUDIO OLIVEIRA EGALON <[e-mail]>
Subject: Space Scientist
Newsgroups: sci.space

You can be a technitian to work for  NASA as space scientist but you would have a
better chance if you have a college (university) degree. This degree can be in
Engenering, Physics, Chemistry, Astronomy, Metereology etc... Of course if you
have a Ph.D. or M.Sc. you have more changes but I think that a B.Sc. is enough.

[e-mail]

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

Date: Tue, 2 Mar 1993 20:26:58 GMT
From: Kenji Saito <[e-mail]>
Subject: Stupid Fred Question
Newsgroups: sci.space

In article <[e-mail]> you write:
>In the close-up GIF of the space station,
>on the one module, what does NASDA stand for ?

NASDA is the Japanese version of NASA. I do not know what the name stands
for, but it must be something like National AeroSpace D? Agency. The module
must be JEM, Japanese Experimental Module.

-Kenji Saito
 Department of Computer Science
 Cornell University

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

Date: Tue, 2 Mar 1993 20:39:24 GMT
From: Henry Spencer <[e-mail]>
Subject: Water resupply for SSF (?)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>>>[automated comet mining]
>>Someday.  Not today.  This is *far* beyond what can be done with current
>>robotic systems.
>
>The two most complicated pieces of automation needed are
>(a) ice extraction and (b) solar mirror deployment (for the solar
>thermal version).  Surely you have some confidence in (b), or you
>wouldn't have been designing solar sails for the contest...

Ho ho.  It's obvious Nick has never designed a solar sail. :-(  The
deployment phase is the single diciest part of a sail design, even
with the broad tolerances of a sail, with the possible exception of
heliogyro-type concepts.

>As for
>(a), a similarly complex operation, the extraction and return of
>several comet core samples, keeping them pristine-pure the entire way
>back to earth and through reentry, has been considered feasible
>in the space science community since the mid-1980s...

Slight correction:  it's been considered worth a try, as a high-risk
high-payoff mission, since the mid-1980s.  As I recall, problems like
preservation of the samples during return were considered minor ones
compared to the difficulties and uncertainties of the comet-surface
operations.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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


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Good Luck.

Anything you can talk about?

pat

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End of Space Digest Volume 16 : Issue 267
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