Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_4/V16NO418.TXT

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Date: Sun,  4 Apr 93 05:07:30
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #418
To: Space Digest Readers
Precedence: bulk


Space Digest                Sun,  4 Apr 93       Volume 16 : Issue 418

Today's Topics:
                         Atlas rocket questio
                          Metric vs English
                         NASA (dis)incentives
                    Prefab Space Station? (2 msgs)
                         pushing the envelope
               Small Astronaut (was: Budget Astronaut)
                         Why is Venus so bad?

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Date: 03 Apr 93  07:59:00
From: [e-mail]
Subject: Atlas rocket questio
Newsgroups: sci.space

P >
P >AW had an article that mentioned the improvements in the launcher
P >families,  and cited the Atlas 2AS???  as an example of what can happe
P >with incremental improvement of existing launchers.
P >
P >MY question is what sort of gains are we getting out of these?

The original Atlas could put about 2200 lbs (as in a Mercury capsule) into
LEO, back in the early 1960's. Today's Atlas IIAS can orbit 18,000 lbs.


___ WinQwk 2.0b#0

--- Maximus 2.01wb

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

Date: Sun, 4 Apr 1993 02:03:09 GMT
From: Keith Mancus <[e-mail]>
Subject: Metric vs English
Newsgroups: sci.space

[e-mail] (Bruce Dunn) writes:
> SI neatly separates the concepts of "mass", "force" and "weight"
> which have gotten horribly tangled up in the US system.

  This is not a problem with English units.  A pound is defined to
be a unit of force, period.  There is a perfectly good unit called
the slug, which is the mass of an object weighing 32.2 lbs at sea level.
(g = 32.2 ft/sec^2, of course.)

>       People working in the US system have thus had to invent two different
> "pounds", the "pound force" and the "pound mass"... SI uses a distinct unit
> of force called a newton.  Pushing on a 1 kilogram mass with a force of
> 1 newton produces an acceleration of 1 m/s^2.

  It is true that many people use "lbm" to mean 1/32.2 of a slug.  Very
sloppy and confusing.  But SI is not a magic bullet; I've seen respectable
engineering papers use "kgf".  That's right, "kilograms force".  If
people don't use the system correctly, nothing will save them.

  Personally, I can work comfortably in either system, but I *despise*
conversions.  Once you start a project in one system, I believe you should
stick to it all the way through.

--
 Keith Mancus    <[e-mail]>                           |
 N5WVR           <[e-mail]>                        |
 "Black powder and alcohol, when your states and cities fall,          |
  when your back's against the wall...." -Leslie Fish                  |

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

Date: 3 Apr 1993 19:52 CST
From: [e-mail]
Subject: NASA (dis)incentives
Newsgroups: sci.space,talk.politics.space

In article <[e-mail]>, [e-mail] (Nick Szabo) writes...
>[e-mail] (Andrew C. Welch) writes:
>
>>Perhaps a solution would be for Congress to let NASA (or any other agency)
>>conduct business the way they choose while at the same time holding them
>>responible for the results.
>
>Problem is, how or why would Congress hold a government agency like
>NASA responsible for its results?  When NASA succeeds (eg Apollo)
>its budget gets cut.  When it fails (eg Challenger) its budget rises.
>With most NASA projects, the greater their cost overrun, the greater
>their revenue stream.  Attempts to reverse this built-in incentive
>towards bureaucracy and failure are shouted down as "NASA bashing", so
>there is no incentive, beyond the most rare self-sacrficing altruistic
>motives, to use political action to correct this situation, even if
>(a) said altruistic lobbyists recognized the problem for what it was,
>(b) knew how to correct it, and (c) were effective enough to reverse
>decades of contracting practice, attitude, and habit.  In my experience,
>with all due appreciation towards Allen Sherzer and several of his colleagues
>valiantly struggling against the corruption of NSS activism by NASA
>lobbyists, there is no group of space activists that come anywhere close to
>meeting these lofty demands, and thus no effective way of holding NASA
>responsible for failures, or rewarding it for successes.
>
>

Now black when it is white is just white. Except that when black is called
white money is put into the system in a study to find out just when it is
justified to call black, white.  It is also apparant that when white is called
black, just the opposite occurs. Now white is a color, but when white is
called black, it calls into question the validity of the color spectrum.
Now is the color spectrum, black or white? When white is called black a
government/industry/university consortium can be formed that will be an
order of magnitude more expensive to find out the ultimate validity of the
postulation. However when private industry that is doing cometary resource
utilization work is contracted the entire solar system benefits? Why, you the
gentle reader may ask?  Because it is clearly evident to even the most
casual observer that the government could never ever figure out the difference
between black and white. At most the question will devolve into one of how
white is black and how black is white? At most this will become a grey
area of study.

It is a given however that NASA nor the military, whose competence in
differentating black from white is well known (remember the black and
white paint on the Saturn V rocket?) That nothing will occur here either.
When black and white are used by congress, who cares nothing for results,
just more money for pork barrel jobs brought about by the black/white
controversy.  Also this is good for NASA and its contractors who by the
look of things could turn this into the technology development of the
century thereby helping the Clinton administration in its bid to
develop new technology to fight the incursion of the Japanese and their
grey area tactics.

Note: This makes as much sense as the first part of this post.

Dennis, University of Alabama in Huntsville

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

Date: Sun, 4 Apr 1993 03:41:57 GMT
From: Frank Crary <[e-mail]>
Subject: Prefab Space Station?
Newsgroups: sci.space

In article <1pl3f8$[e-mail]> [e-mail] (Andy Carol) writes:
>Since one of the largest expenses of Freedom will be the many trips
>required to get the pieces up, and the many EVAs required to put
>the whole thing together, why do they not consider a lesson from
>SkyLab?

>Build a prefab station module similar to a shuttle in size and design
>except it will never return to Earth and will not be manned at launch.
>Because it is never going to land, it does not need wings, landing
>gear, most avionics etc.  It will be, in effect, a module with 3 large
>shuttle engines mounted under it which will only get one use.

This is, essentially, the Shuttle-C concept: A idea which was
fairly popular a few years ago, but which seems to have faded into
obscurity. The idea was to develop a 75-tonne to orbit launch
vehicle, using the Shuttle SRBs, ET and two main engines. Some
studies concluded that Space Station Freedom components could
be launched in only three or four Shuttle-C missions, plus two
or three Shuttle missions for assembly. NASA rejected this
concept, for reasons that would be better suited for
talk.politics.space...

>A shuttle could be used to ferry the crew up.  Emergency return would
>still be difficult (like with Freedom), maybe we could 'buy' a Russion
>vehicle.

Or build our own: The Shuttle isn't well suited for crew transfers,
but there are designs floating around for ~10 tonne, 6-man crew
capsules, that would be very effective for such roles.

                                                       Frank Crary
                                                       CU Boulder

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

Date: Sun, 4 Apr 1993 00:38:51 GMT
From: Dave Michelson <[e-mail]>
Subject: Prefab Space Station?
Newsgroups: sci.space

In article <1pl3f8$[e-mail]> [e-mail] (Andy Carol) writes:
>
>Since one of the largest expenses of Freedom will be the many trips
>required to get the pieces up, and the many EVAs required to put
>the whole thing together, why do they not consider a lesson from
>SkyLab?
>
>Build a prefab station module similar to a shuttle in size and design
>except it will never return to Earth and will not be manned at launch.
>Because it is never going to land, it does not need wings, landing
>gear, most avionics etc.  It will be, in effect, a module with 3 large
>shuttle engines mounted under it which will only get one use.  It would
>also need OMS engines etc.  The 'one-launch' idea may also allow savings
>with structure design.

Of all the space station concepts, I always liked the Manned Orbital
Systems Concept (MOSC) from 1975...

Developed by McDonnell Douglas Astronautics for the Marshall Space Flight
Center, the concept envisaged a basic facility comprised of four modules
derived from Spacelab hardware.  The "station" would be brought to orbit
in two shuttle flights.  A solar array would generate 25 kW of power with
8 kW available for scientific payloads and such.  A crew of four would stay
for about 90 days before rotation.

Such a station would provide much valuable experience at a fraction of the
cost of Freedom, particularly in life sciences research.  It wouldn't last
for more than a few years before requiring replacement.  But, at this point
in our experience, that sounds more like a feature than a flaw...

A reasonably good description is presented by J.D. Hodge and C.C. Priest
in "The Space Station: An Idea Whose Time Has Come."  (T.R. Simpson, Ed.)
(New York: IEEE Press, 1985, pp 126--128.)

It is unfortunate that MOSC (in some ways, a SkyLab mark II) was abandoned
as NASA's emphasis shifted from research in orbit to space construction.
It seems that one can obtain funding and political support for grandiose
projects like Freedom and NASP much more easily than for intrinsically more
sensible projects like MOSC and HALO.

<sigh>

---
Dave Michelson                             University of British Columbia
[e-mail]                                  Antenna Laboratory

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

Date: Sat, 3 Apr 1993 23:31:54 GMT
From: Elijah Millgram <[e-mail]>
Subject: pushing the envelope
Newsgroups: sci.space

A friend of mine and I were wondering where the expression "pushing
the envelope" comes from.  Anyone out there know?

Thanks,

Lije

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

Date: Sat, 3 Apr 1993 10:19:37 GMT
From: Dave Michelson <[e-mail]>
Subject: Small Astronaut (was: Budget Astronaut)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] ("RWTMS2::MUNIZB") writes:
>
>Does anyone know where I can rent/buy a video copy of "Destination Moon"?

According to Leonard Maltin's 1992 Movie and Video Guide, you might try

   Movies Unlimited
   6736 Castor Avenue
   Philadelphia, PA  19149

   800-523-0823
   215-722-8398
   215-725-3683 (fax)

Maltin describes this place as "the definitive source for practically
every currently available video in print".

There are many other mail-order sources for videos, though.  Check out
Maltin's book... (And let us know what you find out!)

It's too bad that the Conquest of Space isn't available on home video
as well. <sigh>

---
Dave Michelson                             University of British Columbia
[e-mail]                                  Antenna Laboratory

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

Date: 3 Apr 1993 20:30:51 -0500
From: Pat <[e-mail]>
Subject: Why is Venus so bad?
Newsgroups: sci.space,rec.scuba

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In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>In <1pchne$[e-mail]> [e-mail] (Pat) writes:
>The Navy dive tables are maximum numbers assuming divers in very good
>physical condition.  Personally, I would be inclined to use a *large*
>safety margin with them.



The Commercial divers do seem to be in very good physical conditions.
Granted i have only met 2,  but they didn't seem to be louts.

The big problem seems to be management wants to save money, by
saying the table is the safety margin.

The navy also has the advantage of their divers move on to
other activities after a few years,  Commercial divers
work for years.

Of course, this illustrates, that even a "Well Known" technology
can still have hidden risks  that take a while to be discovered.

pat

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End of Space Digest Volume 16 : Issue 418
------------------------------