Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V09_2/V9_265.TXT

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Subject: SPACE Digest V9 #265

SPACE Digest                                      Volume 9 : Issue 265

Today's Topics:
           Re: Manned vs unmanned space exploration
        Re: An integrated space program for the world
               Re: the un/manned debate
        Re: Orbital debris study completed (Forwarded)
              Re: Space colonies
            NASA, Soviets, gripes
             Re: Synthetic Aperture Radar
               Re: the un/manned debate
              Re: 1992 moon base
              Re: Voyager Images
           Re: What ever happened to NERVA?
             Re: approaching "C"
----------------------------------------------------------------------

Date: 22 Feb 89 17:58:33 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Manned vs unmanned space exploration

In article <[e-mail]> [e-mail] (John McKernan) writes:
>... It's interesting to think about how little of NASA would
>be left if all launch activities, the unmanned space program, and the space
>station were removed.

Yeah, you'd be left with just the technology R&D... supposedly NASA's primary
purpose in life...

> In my opinion the station is premature at current launch
>costs, and I know some of Henry's postings have been critical of it, though I
>can't say for sure whether he supports building the station now or not.

I have deeply mixed feelings about the current space station project.
I don't consider launch costs a major factor, though -- that's not a big
part of the budget for it.  I don't think it's impossible to build a good
and relatively economical space station at current launch costs, but I
don't think NASA can.

The space-station concept I liked was Art Dula's:  you keep the hardware
costs modest by having it built by construction companies instead of
aerospace contractors, and you get cheap and prompt launches by buying
them from the Soviets.
--
The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
our nine months are up.        | uunet!attcan!utzoo!henry [e-mail]

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

Date: 22 Feb 89 21:48:54 GMT
From: minke![e-mail]  (Nick Szabo)
Subject: Re: An integrated space program for the world

In article <[e-mail]> [e-mail] (Tim Shimeall x2509) writes:

[Concerning "terraforming" the Sahara]
>I'll also invite you to consider the social effects of converting the
>Sahara into farmland.  There are widespread and ancient cultures built
>around desert life, with many active advocates.  I don't think that
>they'll welcome the sacrifice of their culture.
>
>Note that these criticisms apply ONLY to the Sahara reclamation
>process.  Terraforming Mars involves nothing close to these political
>problems.

Actually, similar problems might arise, if the project to terraform Mars
starts after the first Martian settlements are already laid down.  Granted,
these won't be ancient cultures, but imagine crashing comets or seeding
genetically engineered organisms (to name just a couple of terraforming
techniques) onto an already inhabited planet.  These issues may need to be
resolved before the first Mars bases and settlements are laid down.
Should the terraformation of Mars be sacrificed for the sake of its first
settlers?  Or vice-versa?



Nick Szabo              [e-mail]

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

Date: 22 Feb 89 17:34:17 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] (John McKernan) writes:
>... The focus of unmanned space today is launching
>probes with the launchers we have now, not building new launchers.

In fact, one sometimes gets the impression that unmanned space today isn't
interested in *anything* that won't help their current missions.  Give
them all the money they want, and they'll still be flying the same sort
of missions a century from now. :-)  "We can't fund your new technology
because no current mission requires it.  And of course we can't design
it into any of our missions until it's developed properly.  And of course
our current missions should have priority over developing it."
--
The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
our nine months are up.        | uunet!attcan!utzoo!henry [e-mail]

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

Date: 22 Feb 89 08:32:50 GMT
From: portal!cup.portal.com![e-mail]  (H Keith Henson)
Subject: Re: Orbital debris study completed (Forwarded)

A proposal I have not seen (doesn't mean it hasn't been made) to clean up
orbital debris would be to construct one large ground based laser and a few
orbital redirection mirrows.  Very small stuff could be vaporized, but even
the large pieces could be de-orbited and dumped into the atomosphere by
vaporizing a small fraction of the junk on the forward (in orbit) side.

There should be several groups that could support this project.  The laser
would be useful for launching material, and it would provide definative
answers to many SDI projects.  One system would not be enough for significant
defense, so those opposing SDI might not fight it.  And after all, it is
a cleanup project, so we might get environmental support.

Keith Henson, a founder of the L5 Society

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

Date: 22 Feb 89 06:06:13 GMT
From: blake!ogccse!littlei!omepd!psu-cs!reed![e-mail]  (Michael Sandy)
Subject: Re: Space colonies

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>>According to my sources existing technology *is* more or less adequate
>>to the task of building space colonies -- at least there are no
>>"show-stoppers" --, it's just that they're not *affordable*.  What's
>>needed is cheaper space transportation, more experience working in
>>space, and a good economic motive for building them.
>
>I consider orders of magnitude too expensive == inadequate by orders
>of magnitude.
>
>We don't need experience if that experience will not be applied for
>decades.  Consider all the experience gained in Apollo, and subsequently
>lost, because it wasn't "steam engine time".
>
>    Paul F. Dietz
>    [e-mail]

Hi!  I just started reading this newsgroup, but since I recently read an
article relevant to this discussion, I thought I'd share.

There already is a "much cheaper space transportation technology" in the
works, like 20$ per pound of payload to get to orbit.  Its based on the
good 'ole electromagnetic railgun.  The current technology can get
small (~1 pound) objects up to 4 miles per second by accelerating them
at 48,000 g.  Current technology, and technology that can easily be
developed in the next ten years can make semi-conductors and other
electronic packages capable of withstanding that acceleration.  A launch
facility that could launch payloads of up to a ton could be built for
300 million dollars, a fraction of the space shuttle cost.  Used in conjunction
with the shuttle, with the shuttle transporting such fragile things as
humans and the rail launcher the more massive stuff, we could redo the
moon launch project like it was originally intended.

The original plan had the US first establishing space stations as refueling
points.  With a cheap method for getting fuel into orbit and other new
technologies like the ion drive the solar system is back in reach again.

The article in question was the February 1989 Discover.

Michael Sandy
[e-mail]

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

Date: 23 Feb 89 05:29:11 GMT
From: silver![e-mail]  (thomas matzat)
Subject: NASA, Soviets, gripes



    Here we sit, waiting patiently for the next shuttle launch,
while the Soviets have tested not only a new HLV, but their own
shuttle.  As much as I hate to say it, the Soviet space program
has got NASA beat bad.  I say this because I'm really sick of seeing NASA,
and the U.S. government in general, screw up time and time again!

    The Soviets have built up a great deal of confidence in
their equipment over the years, to the point where they can test
their shuttle on a booster that's only being launched for the
second time, and do it all by remote control.  Hell, we can't
even launch a satellite on a Titan II without worrying about it
blowing up!

    The Soviet space program has built itself up the slow, but
cautious way by basing the next generation of lifter and spacecraft
on the previous design.  It has been slow, but it has worked.  NASA
started out that way, but got hooked on the glitz and promise of
the shuttle.  Developing new technology is fine, but NASA was in such
a rush to "beat the Russians", that they lost sight of what they
should have been doing: Improving on the Saturn V and putting up a
space station a bit more permanent than Skylab.  Instead, they scrap
our only REAL HLV and go all out for the space shuttle, a plan which
hurt NASA in the long run.   Now NASA is in a position where it will
take them twice as long as the Soviets to put up a "real" space station.
With Energia and Buran, the Soviets could build a large station in no
time at all.  Mir could serve as the base for all of this construction.
Just add a few modules, and presto, instant large scale space station.

    Right now I believe NASA can do one of two things:

        1) Spend large sums of money on bringing back the
           Saturn V or building an HLV from scratch, and
           getting the space program going in the right
           direction again.

                    or

        2) Work together with the Soviets , ESA, and any
           other space program that wants to get in on the
           act, because it's going to take more money than
           any one country can come up with to really
           explore space in the right way.
           (My definition of the "right way" is by moving
            from space stations, to a Moon base, to Mars, etc.
            in an organized, cautious, and PERMANENT manner.)

    These are my ramblings on this whole affair.  If I have offended
anyone, I apologize.  If you have a different opinion, I'd like to hear
it.


                        -Tom
                             "the illogical one"

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!    Thomas R. Matzat    !  UUCP: {inuxc,rutgers,pyramid,pur-ee}!   !
!    Indiana University  !        iuvax!silver!matzatt              !
!    Bloomington, In.    !  ARPA: [e-mail]   !
!!!!!!!!!!!!!!!!!!!!!!!!!!  BITNET: [e-mail]           !
!                                                                   !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

DISCLAIMER: These are my opinions only.  (Who else would want them?)

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

Date: 22 Feb 89 21:27:07 GMT
From: math.ucla.edu!julia![e-mail]  (Harold Wong)
Subject: Re: Synthetic Aperture Radar

In article <[e-mail]> [e-mail] (Tom Mitchell) writes:
>In article <[e-mail]>, [e-mail] (Joe Dellinger) writes:
>
>The best way to research this is a computer search on the "Palmdale
>Bulge".  There was a large bunch of articles c.5 years back when
>someone noted that geodedic leveling indicated a 'uplift' of a
>large area adjadcent to the San Andreas fault.
>
>As always only believe a bit of what you read,
>

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?


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

Harold Wong         [phone]
UCLA-Mathnet; 3915F MSA; 405 Hilgard Ave.; Los Angeles, CA 90024-1555
ARPA: [e-mail]          BITNET: hgw%math.ucla.edu@INTERBIT

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

Date: 23 Feb 89 04:20:01 GMT
From: minke![e-mail]  (Nick Szabo)
Subject: Re: the un/manned debate

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

>one sometimes gets the impression that unmanned space today isn't
>interested in *anything* that won't help their current missions.

You are caught up in your own rhetoric, Henry.  I can't speak for specific
scientists, but unmanned activities in general are far more future-oriented
than manned projects, which exist mainly to satisfy the present pleasure of
witnessing a few people in space.  The future-oriented aspects of our
space program--private industry in space, exploration of the entire solar
system instead of just LEO, the development of deep-space communications and
operations, etc.--are unmanned.  You will note that I have not been advocating
*just* unmanned; I have been advocating unmanned *and* basic R&D.  Both have
been shafted by funding priorities.  (As an aside, note that the development
of EML and gas-gun technology is far more relevant to unmanned than manned
activities.  Cheap unmanned launch methods will enable us to send thousands
of probes to all corners of the solar system, and later to launch automated
prospecting and mining missions.)


Nick Szabo              [e-mail]

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

Date: 22 Feb 89 17:50:12 GMT
From: mahendo!jato!jpl-devvax![e-mail]  (Larry Wall)
Subject: Re: 1992 moon base

: >While earth-operated rovers may be slower, they could be operated around
: >the clock (at least during the lunar day).  Earth-bound operators would be
: >many times less expensive than lunar colonists.
:
:     I fail to see why rovers couldn't be operated around the clock,
: period.  Putting searchlights on them is no big deal.

You'd almost certaintly want to keep them operating to avoid getting them
too cold.  Even if nothing is overtly damaged by the cold, the thermal
cycle is vicious.

Unless you make the rovers so they can dig in for the lunar night, of course.
Even then, you want to produce enough heat to offset what is lost through
whatever insulation you've collected around the rover.

On the other hand, if you've designed them to run at night, the problem
may be to get rid of the excess heat during the day...

Larry Wall
[e-mail]

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

Date: Thu, 23 Feb 89 10:11:03 PDT
From: Peter Scott <[e-mail]>
Subject: Re: Voyager Images
X-Vms-Mail-To: EXOS%"[e-mail]"
Cc: romeo![e-mail]

romeo![e-mail]  (Bob Currier - DCAC Network Comm. Specialist)
writes:

>Does anyone know if the Voyager images are available to the public?
>If so, can they be obtained in machine-readable format, i.e. 9 track
>tape, or better yet, by anonymous FTP?  For that matter, are there
>*ANY* images available free of charge, or for a modest fee that can be
>had for experimentation with image processing?
>
>We want to use our new NeXt box to play with the images...

The Voyager Imaging Library here says that the images are not available
in machine-readable form to the public at present, *however*, the NSSDC
*does* plan to release them on CD-ROM in the near future.

Peter Scott ([e-mail])

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

Date: 23 Feb 89 00:21:49 GMT
From: amdcad!weitek!sci![e-mail]  (Dave Rickel)
Subject: Re: What ever happened to NERVA?

I had heard that NERVA, in spite of having such a good specific impulse
(the number posted (800 sec) (ick--specific impulse should be a velocity)
looks to be about twice that of the SSME--did i mess up in the conversion
somewhere?), was no better, and indeed a bit worse, than a chemical rocket.
The problem was that the NERVA engine was much heavier than a conventional
chemical rocket engine with the same thrust; in most of the proposed missions
you could get better (and more reliable) performance by using a chemical
rocket and some extra fuel.  Of course, that's an unfair comparison--comparing
a mature technology (chemical rockets) to a developing technology (nuclear
rockets), but what the hell.  The anti-nuclear movement of the 60's certainly
didn't help NERVA along any.


david rickel
decwrl!sci!daver

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

Date: 22 Feb 89 01:34:56 GMT
From: tektronix!tekig5![e-mail]  (Robin Adams)
Subject: Re: approaching "C"


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.

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).

If it does'nt, it seems like the ship would pile into its own photons.
- Did I miss something?



                       o         o                o
                                              o                  o
                    o                  o            o
----------------------------------------------------------------------------
                            |       |
                            |       |   Robin
                           /---------\  Adams

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

End of SPACE Digest V9 #265
*******************