Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V09_2/V9_267.TXT

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Subject: SPACE Digest V9 #267

SPACE Digest                                      Volume 9 : Issue 267

Today's Topics:
          Re: Forbes article on manned space program
Re: Cosmos mission results and future U.S./USSR missions announced (Forwarded)
              Re: 1992 moon base
    Discover article on railguns (was Re: Space colonies)
             Re: approaching "C"
Re: Cosmos mission results and future U.S./USSR missions announced (Forwarded)
               Re: the un/manned debate
    The Palmdale Bulge (was Re: Synthetic Aperture Radar)
              Re: 1992 moon base
              Re: MARS the Movie
               Re: the un/manned debate
----------------------------------------------------------------------

Date: 24 Feb 89 04:10:53 GMT
From: minke![e-mail]  (Nick Szabo)
Subject: Re: Forbes article on manned space program

[Free fall health problem]
>It is noted that merely rotating a space station is not a reasonable
>solution, the example given being that to generate 1 g at 1 rotation per
>minute requires a station either 10 miles wide, or a tether with a counter-
>balance of the same length, not a trivial engineering problem.

Do we need 1 g, and do we need 1 rotation per minute?  I suggest an experiment
using long tethers, with small biological modules spaced at intervals
(or sliding) to provide various levels of gravity from 0 to 1 g.  For
example, a module could be placed for a time at lunar gravity (g/6).  The
rotation rate would be varied.  Small mammals, such as mice, would be placed
in the modules, observed, and experimented with.  The minimum healthy levels
of gravity and rotation would thereby be found.



Nick Szabo              [e-mail]

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

Date: 23 Feb 89 19:06:07 GMT
From: blake![e-mail]  (Michael M. Martinez)
Subject: Re: Cosmos mission results and future U.S./USSR missions announced (Forwarded)

In article <[e-mail]> [e-mail] (Peter E. Yee) writes:
>RELEASE:  89-18
>
>COSMOS MISSION RESULTS AND FUTURE U.S./USSR MISSIONS ANNOUNCED

[lots of stuff deleted]

>     Muscle studies on the rats showed that, while individual
>muscle weights were similar for both flight and ground control
>animal groups, the fast muscle types showed significant decrease
>in cross-sectional area, atrophy and extracellular edema, while
>at the same time showing increased necrotic fibers and motor end
>plate degradation.  Slow muscle types showed little evidence of
>atrophy but some biochemical changes.  The mitochondria in the
                                            ^^^^^^^^^^^^
>heart muscle also showed degeneration and fiber changes.
>

I note one thing about which I have a question, and that is the reference to
a loss of mitochondrial fiber. Mitochondria are not tissue, they are organelles
within all procaryotic cells that provide the electron transport necessary to
provide energy. I don't know what possible fiber would be involved with them.
If there is any way that you can use the network to question this wording, I
wish that you would do so for me. Thanks.

Come to think of it, if you can do that, would you also please ask if these
rather dramatic effects of a mere 12 days are reversed upon a longer exposure
to light or null gravity? Surely similar tests must have been done on the
humans who spent such long periods in space.

[  I am posting this question for a friend; please post your comments and I
will forward them. ]

Michael M Martinez
[e-mail]

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

Date: 23 Feb 89 16:43:50 GMT
From: nih-csl![e-mail]  (jim sullivan)
Subject: Re: 1992 moon base

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (daniel mocsny) writes:
>>... We can't just dump people in cans and expect
>>them to huddle heroically while we try to build a reliable launcher to
>>get them back home. We have to give them the tools to not simply
>>survive on the moon, but to take it.
>
>"We can't just dump people in covered wagons and expect them to huddle
>heroically while we try to build a railroad to bring them back."
>
>(Only half :-))

    The analogy does not apply.

>Agreed that a lunar colony has to have enough power over its environment
>to do something practical rather than just huddling.  (If all you can do
>is huddle and wait for the return flight, what you have is a base, not a
>colony.)

    Agreed, but what is wrong with starting with a base which would
    be revisited, each visit bringing along an addition or improvement
    eventually leading to a permanent base or colony.  The USSR
    keeps men in space very long with continual resupply, the moon
    is only a few days away.

           It is a mistake to assume that massive sophistication is needed
>for this, though.  It is also a mistake to assume that 100.00% probability
>of success *must* be assured before making the attempt.  (NASA has done
>spaceflight a huge disservice by propagating the myth that everything can
>be planned in advance and there is no reason for anything to ever go wrong.

    Where is this myth?  Does NASA deny the Apollo I fire, the Soviets
    killed on re-entry a few years ago, Challenger?  What NASA propagates
    is an assurance that all safty procedures possible are undertaken
    and backups to them.  I remember the Apollo flights very well and
    everyone was worried about an accident.  NASA stated that they
    were implementing all safty procedures but no one assumed an accident
    could not occur nor that an accident would stop the program.
    Remember Apollo 13?

>In the long run, the exploration of space will be like the exploration of
>Earth some time ago:  a slightly risky business that occasionally kills
>people and is *expected* to do so, and thus does not stop for agonizing
>reappraisals each time that happens.)

    Yes, people will die just as they do in every exploration project
    since by definition there are many unknowns BUT that does not mean
    that we should just ignore a death or accident and continue on blindly.
    I, for one, am happy to see the shuttle redesigned.  The reappraisals
    are those of how to continue *with more safty* than they are of
    whether to continue at all.

                    Jim Sullivan
                    [e-mail]

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

Date: 23 Feb 89 16:04:43 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Discover article on railguns (was Re: Space colonies)

This article is being discussed in the space-tech mailing list, where
previously gun-type launchers using chemical energy were discussed.
The opinion of several contributors seems to be that the ram
accelerator is simpler and potentially cheaper than the railgun for
use as a launcher.  Also, it would subject its payloads to lower
accelerations, perhaps 1000 g.

If nothing else, a low cost launcher that could send bulk materials to
LEO (and higher orbits) would make many space operations less
expensive.  For example, you could launch consumables to a space
station and avoid the need for closed cycle life support, or you could
use it to launch rocket fuel for use in and beyond earth orbit.  Many
raw materials for space construction are acceleration insensitive.

It was claimed in space-tech that a laser launch system could be
developed in 5 years for $500 M; the system would have a max
acceleration of 5 g.

It kinda makes you wonder what we're getting for $10B+/year, when they
could be working on things like these.  Ah, I know, "experience".  What
a bargain.

    Paul F. Dietz
    [e-mail]

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

Date: 23 Feb 89 16:00:05 GMT
From: mailrus!uflorida!haven!uvaarpa!hudson!astsun1![e-mail]  (Greg Hennessy)
Subject: Re: approaching "C"

Robin Adams writes:
#
#A space ship is travelling through space at 75% light speed. It is headed
#toward our moon and is 50,000 miles distant. A powerful laser is mounted at
#the front of the space ship. When the beam is switched on, the light should
#reach the moon in approximately 0.27 seconds.

For an observer on the earth fine. An observer on the ship would see
it arrive in a different amount of time.

#
#Regardless of where any observer is, the photons in the beam would appear to
#impact the surface at a speed greater than "C" (This is a kind of Michelson -
#Morley experiment out in the open).
#

No. regardless of where any observer is, the photons in the bean would
appear to impact the surface at a speed of EXACTLY "C". (This is a
kind of Special Relativity experiment out in the open.)


#If it does'nt, it seems like the ship would pile into its own photons.

The ship sees the photons traveling ahead of the ship at exactly "C".
It never piles into its own photons.

#- Did I miss something?

Special Relativty. Try Taylor and Wheelor, Special Relativity.
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 23 Feb 89 22:16:29 GMT
From: csli![e-mail]  (John Kallen)
Subject: Re: Cosmos mission results and future U.S./USSR missions announced (Forwarded)

What are the main arguments against not having some kind of "centrifuge"
to generate artificial gravity? Stability reasons (i.e. the whole vessel
would start spinning, making it difficult to dock to it) ? The little
problem that occurs when the bearings of the "centrifuge" jam (oops,
got some angular momentum there :-) ?

Surely such a "centrifuge" module could be added to a space station/vessel
just like any other module...

_______________________________________________________________________________
 | |   |   |    |\ | |   /|\ | John Kallen
 | |\ \|/ \|  * |/ | |/|  |  | PoBox 11215             "Life. Don't talk to me
 | |\ /|\  |\ * |\ |   |  |  | Stanford CA 94309        about life."
_|_|___|___|____|_\|___|__|__|[e-mail]___________________________

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

Date: 23 Feb 89 19:23:47 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: the un/manned debate

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>>one sometimes gets the impression that unmanned space today isn't
>>interested in *anything* that won't help their current missions.
>
>... I can't speak for specific
>scientists, but unmanned activities in general are far more future-oriented
>than manned projects...

"Orbital assembly?  No, no, we don't want any work on orbital assembly,
none of our current projects need it, so we don't care that it would give
much larger payloads for planetary missions."  This was said, almost in
so many words, not too long ago.  The unmanned activities may be "future
oriented" in the sense that their advocates (including Nick) think they
are the Wave Of The Future, but they have demonstrated very little desire
to improve technology in their own long-term interests.  Others have
observed that the planetary-science people aren't pushing for cheaper
launchers, for example.  Much of the technological improvement that does
occur, occurs because people are forced into it:  Galileo will use CCD
imagers because the image tubes used on earlier missions are no longer
in production.

More generally, the most striking thing about most of the reports that
attempt to set goals for future unmanned activity is the near-complete
lack of any underlying long-term vision.  They have no goals, just some
missions they want to fly.
--
The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
our nine months are up.        | uunet!attcan!utzoo!henry [e-mail]

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

Date: 24 Feb 89 05:43:19 GMT
From: shelby!Portia!forel![e-mail]  (Chuck Karish)
Subject: The Palmdale Bulge (was Re: Synthetic Aperture Radar)

In article <[e-mail]> [e-mail] (Harold Wong) wrote:
>If my source is correct, the Palmdale Bulge turned out to be an error in
>instrumentation.  It's suppose to be a long story.  Anybody else know
>anything about it?

    It is, indeed, a long story.  As I understand it, there's still
    disagreement whether the observed changes were significantly
    larger than the expected instrumental error.

    Surveying instruments and techniques, ground based as well as
    satellite-assisted, have improved quite a bit in the last 15
    years, so it would be easier now to document a similar effect
    than it was in the mid '70s.  Indeed, a bulge of about 10 cm.
    (less than the debatable change near Palmdale) was firmly
    documented, in Long Valley.  It was caused by the intrusion of
    a dike into the floor of the caldera left by a large volcanic
    eruption about 725,000 years ago.

    Elevation changes of 15 cm. or more should be detectable with
    careful gravity surveys.  You have to be doing it in the right
    place, though, and such experiments aren't done as often as
    precise surveying is.

    Chuck Karish    [e-mail]
            hplabs!hpda!mindcrf!karish

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

Date: 23 Feb 89 21:14:41 GMT
From: [e-mail]  (Jordan Kare)
Subject: Re: 1992 moon base

In article <[e-mail]> [e-mail] (Keith P. Mancus) writes:
>
>>From the "The Columbus Project" by Hyde, Ishikawa, and
>>Wood:
>
>>Thus the total mass available from 6 flights would have been
>>35.4 tons.  2.7 tons were reserved for a modified Apollo
>>capsule  for emergency return.
>
>    That's some modification...the CSM weighed 55,000 lbs and the
>LM 35,000 lbs.  That's 45 tons.  The fact that you wouldn't need
>the mass to slow down, enter lunar orbit, and land would be helpful,
>but you have to bring more people back now, which should account for
>most of it.  Moreover, if the CSM is landed on the moon instead of
>left orbiting, the fuel requirements go up drastically.
>
No LM.  Much reduced service module -- bare minimum life support
for 6 people for a one-way trip.  Minimum fuel -- just enough
to get out of Lunar orbit and back to Earth.  The emergency
ascent stage (and fuel) to get up to the return capsue was included
in the rest of the mass budget.  Again, the program as a whole
may have been optimistic (and, of course, became impossible after
Challenger), but the basic numbers _were_ carefully checked.

Jordin Kare







.

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

Date: 23 Feb 89 05:34:00 GMT
From: arisia!cdp![e-mail]
Subject: Re: MARS the Movie


>Don't hold your breath; production has been halted due to a battle over
>merchandising right.

Maybe NSS could carry a line of >> Henry Spencer the Tooth Brush >> in the
next Space Shoping....The Catalog Srikes Back.

       Jordan Katz

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

Date: 24 Feb 89 04:50:20 GMT
From: minke![e-mail]  (Nick Szabo)
Subject: Re: the un/manned debate

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>>>one sometimes gets the impression that unmanned space today isn't
>>>interested in *anything* that won't help their current missions.
>>
>>... I can't speak for specific
>>scientists, but unmanned activities in general are far more future-oriented
>>than manned projects...
>
>More generally, the most striking thing about most of the reports that
>attempt to set goals for future unmanned activity is the near-complete
>lack of any underlying long-term vision.  They have no goals, just some
>missions they want to fly.

Alas, for science missions, I must concur.  Most planetary scientists
are more concerned about "the evolution of the solar system" than future
technology development, and surprisingly few are interested in prospecting
or mining.  Meanwhile, surprisingly few space activists are interested in the
99%+ of our solar system beyond the Moon.  The people exploring deep space
ignore the future, and the people exploring the future ignore deep space.
The cultures need to join up, because deep space is the most important part
of our space future.
I suggest the following:
--Space development activists get involved in the planning and promotion
of unmanned planetary missions.  The main reason I am actively campaigning
for the "unmanned" side is to get more future-oriented people involved in
it.
--Planetary scientists explore ways to apply their science, such
as prospecting for resources in space.


Nick Szabo              [e-mail]

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

End of SPACE Digest V9 #267
*******************