Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_1/v16no192.txt

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Date: Wed, 17 Feb 93 05:11:19
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #192
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 17 Feb 93       Volume 16 : Issue 192

Today's Topics:
                          Anonymous posters
                          Cassini Fact Sheet
                           Daniel S. Goldin
                   flashlights aboard the shuttle?
                            Life on Saturn
                        Mars observer arrival
                         NASA Select (2 msgs)
                  Nobody cares about Fred? (2 msgs)
                       Privatization of space s

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

Date: Tue, 16 Feb 93 21:27:53 EST
From: Tom <[e-mail]>
Subject: Anonymous posters

How about a FAQ regarding anonymous posts?  I think this issue has
brought up enough discussion to warrant it.  If there isn't one already,
I'd be willing to write up a paragraph or two about them.

I figure if it includes a good representation of people's feelings
about anonymous posters and their opinions, as well as a way to
deal with unwanted anonymous posts, as the system currently
operates, that should cover most of what all the posts (both from
anon. and about anon.) have been about.

It could even be included in the FAQ on netiquette.  Problem is, I
forgot who/how to add to the FAQ's.  I suppose I'll learn that when
the FAQs come around again :-)

BTW, until the FAQ exists, and people can just refer to it, instead of
going over and over the same ground, does anyone know a way to rig
a kill file to remove any message about anonymous posts, rather than
just posts from anonymous-ies?

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: 16 Feb 1993 17:22 UT
From: Ron Baalke <[e-mail]>
Subject: Cassini Fact Sheet
Newsgroups: sci.space,sci.astro,alt.sci.planetary

                     FACT SHEET: THE CASSINI MISSION
                           February 15, 1993

     Circled by distinctive rings and attended by a coterie of a
dozen and a half moons, Saturn has been called one of the most
intriguing planetary realms in the solar system.  Its largest
moon, Titan, boasts organic chemistry that may hold clues to how
life formed on the primitive Earth.

     Saturn and Titan will be the destination for the Cassini
mission, a project under joint development by NASA, the European
Space Agency and the Italian Space Agency.  The U.S. portion of
the mission is managed for NASA by the Jet Propulsion Laboratory.

     After arriving at the ringed planet, the Cassini orbiter
will release a probe, called Huygens, which will descend to the
surface of Titan.  The Cassini orbiter will then continue on a
mission of at least four years in orbit around Saturn.


MISSION PROFILE

     Launched in October 1997 on a Titan IV-Centaur rocket from
Cape Canaveral, Florida, Cassini will first execute two gravity-
assist flybys of Venus, then one each of the Earth and Jupiter to
send it on to arrive at Saturn in June 2004.

     Upon reaching Saturn, Cassini will swing close to the planet
-- to an altitude only one-sixth the diameter of Saturn itself --
to begin the first of some five dozen orbits during the rest of
its four-year mission.

     In late 2004, Cassini will release the European-built
Huygens probe for its descent of up to two and a half hours
through Titan's dense atmosphere.  The instrument-laden probe
will beam its findings to the Cassini orbiter to be stored and
finally relayed to Earth.

     During the course of the Cassini orbiter's mission, it will
execute some three dozen close flybys of particular bodies of
interest -- including more than 30 encounters of Titan and at
least four of selected icy satellites of greatest interest.  In
addition, the orbiter will make at least two dozen more distant
flybys of the Saturnian moons. Cassini's orbits will also allow
it to study Saturn's polar regions in addition to the planet's
equatorial zone.

     Throughout the mission, costs will be contained and
efficiency enhanced by streamlined operations.  The Cassini
Project uses simplified organizational groups to make decisions;
flight controllers will take advantage of high-level building
blocks of spacecraft action sequences to carry out mission
activities.


SATURN SCIENCE

     "I do not know what to say in a case so surprising, so
unlooked for and so novel," Galileo Galilei wrote in 1612.  The
source of the Italian astronomer's astonishment:  Only two years
after he discovered them, the rings of Saturn vanished before his
eyes.

     Not that Galileo, however, recognized the rings for what
they were when he first sighted them in 1610.  Having recently
discovered Jupiter's major moons, he assumed that what he saw
next to Saturn were two sizable companions close to the planet.
Two years later, however, they abruptly disappeared.  In a few
more years, they mysteriously returned, larger than ever.
Galileo concluded that what he saw were some sort of "arms" that
grew and disappeared for unknown reasons.

     Nearly half a century later, the Dutch scientist Christiaan
Huygens solved the puzzle that vexed Galileo.  Thanks to better
optics, Huygens was able to pronounce in 1659 that the companions
or arms decorating Saturn were in fact a set of rings.  The rings
were tilted so that, as Saturn orbited the Sun every 29 years,
the sheet of rings would occasionally seem to vanish as viewed
on-edge from Earth.

     While observing Saturn, Huygens also discovered the moon
Titan.  A few years later, the French-Italian astronomer Jean-
Dominique Cassini added several other key Saturn discoveries.
Using new telescopes, Cassini discovered Saturn's four other
major moons -- Iapetus, Rhea, Tethys, and Dione.  In 1675, he
discovered that Saturn's rings are split largely into two parts
by a narrow gap -- known since as the "Cassini Division."

     We now know that Saturn is one of four giant gaseous (and
ringed) planets in the solar system, joined by Jupiter, Uranus,
and Neptune.  Second in size only to Jupiter, Saturn is nearly
ten times the diameter of Earth and its volume would enclose more
than 750 Earths.  Even so, its mass is only 95 times that of
Earth; with a density less than that of water, it would float in
an ocean if there were one big enough to hold it.

     Unlike rocky inner planets such as Earth, Saturn and the
other gas giants have no surface on which to land.  A spacecraft
pilot foolhardy enough to descend into its atmosphere would
simply find the surrounding gases becoming denser and denser, the
temperature progressively hotter; eventually the craft would be
crushed and melted.

     A large, modern telescope will reveal Saturn banded in pale
yellow and gray; photos from the Voyager 1 and 2 spacecraft that
flew by Saturn in the early 1980s showed even more detail in the
cloud tops of its upper atmosphere.  Its neighbor Jupiter runs
toward reds, whereas the more remote Uranus and Neptune are
shades of blue.

     Why the distinctive colors?  The answer, in part, is because
of how far each planet is from the Sun.  This in turn determines
the temperature, which decides which chemicals will be gases,
fluids or ices.  At Saturn -- some 10 times more distant from the
Sun than the Earth is -- the temperature is about -180 C (-290
F).  In addition to two primary, colorless gases -- hydrogen and
helium -- ammonia is relatively plentiful in the planet's upper
atmosphere.  We do not understand fully, however, the source of
the colors in Saturn's clouds -- an issue that the Cassini
mission may well resolve.


The Rings

     Although the best telescopes on Earth show three nested main
rings about Saturn, we now know that the ring system is a
breathtaking collection of thousands of ringlets.  They are not
solid but rather are made up of countless unconnected particles,
ranging in size from nearly invisible dust to icebergs the size
of a house.  The spacing and width of the ringlets are
orchestrated by gravitational tugs from a retinue of orbiting
moons and moonlets, some near ring edges but most far beyond the
outermost main rings.  Instruments tell us that the rings contain
water ice, which may cover rocky particles.

     There are ghostly "spokes" in the rings that flicker on and
off.  What causes them?  Scientists believe they may be
electrically charged particles, but we do not really know.  Where
do the subtle colors in Saturn's rings come from?  We cannot say;
the Cassini mission may well provide the answer.

     And what is the origin of the rings themselves?  One theory
is that they are the shattered debris of moons broken apart by
repeated meteorite impacts.  Another theory is that the rings are
leftover material that never formed into larger bodies when
Saturn and its moons condensed.  Scientists believe that Saturn's
ring system may even serve as a partial model for the disc of gas
and dust from which all the planets formed about the early Sun.
The Cassini mission will undoubtedly give us important clues.


Mysterious Moons

     Saturn has the most extensive system of moons of any planet
in the solar system -- ranging in diameter from about 20
kilometers (12 miles) to 2,575 kilometers (1,600 miles), larger
than the planet Mercury.  Most are icy worlds heavily studded
with craters caused by impacts very long ago.

     The moon Enceladus, however, poses a mystery.  Although
covered with water ice like Saturn's other moons, it displays an
abnormally smooth surface; there are very few impact craters on
the portions seen by Voyager.  Has much of the surface of
Enceladus recently melted to erase craters?  Could the moon also
contain ice volcanoes that provide particles for Saturn's most
distant faint ring beyond the three main rings?

     Saturn's moon Iapetus is equally enigmatic.  On one side --
the trailing side in its orbit -- Iapetus is one of the brightest
objects in the solar system, while its leading side is one of the
darkest.  Scientists surmise that the bright side is water ice
and the dark side is an organic material of some kind.  But how
the dark material got there is a mystery.  Did it rise up from
the inside of the moon, or was it deposited from the outside?
The puzzle is compounded by the fact that the dividing line
between the two sides is inexplicably sharp.


Titan

     But by far the most intriguing natural satellite of Saturn
is its largest.  Titan lies hidden beneath an opaque atmosphere
more than fifty percent denser than Earth's.  Titan has two major
components of Earth's atmosphere -- nitrogen and oxygen -- but
the oxygen is likely frozen as water ice within the body of the
moon.  If Titan received more sunlight, its atmosphere might more
nearly resemble that of a primitive Earth.

     What fascinates scientists about Titan's atmosphere is that
it is filled with a brownish orange haze made of complex organic
molecules, falling from the sky to the surface.  Thus in many
ways it may be a chemical factory like the primordial Earth.

     Most scientists agree that conditions on Titan are too cold
for life to have evolved -- although the most daring speculate
about the possibility of lifeforms in covered lakes of liquid
hydrocarbons warmed by the planet's internal heat.  Yet even if
Titan proves to be lifeless, as expected, understanding chemical
interactions on the distant moon may help us understand better
the chemistry of the early Earth -- and how we came to be.


THE CASSINI SPACECRAFT

     The Cassini orbiter weighs a total of 2,150 kilograms (4,750
pounds); after attaching the 350-kilogram Huygens probe and
loading propellants, the spacecraft weight at launch is 5,630
kilograms (12,410 pounds).  Because of the very dim sunlight at
Saturn's orbit, solar arrays are not feasible and power is
supplied by a set of radioisotope thermoelectric generators,
which use heat from the natural decay of plutonium to generate
electricity to run Cassini.  These power generators are of the
same design as those used on the Galileo and Ulysses missions.

     Equipment for a total of twelve science experiments is
carried onboard the Cassini orbiter.  Another six fly on the
Huygens Titan probe, which will detach from the orbiter some four
to five months after arrival at Saturn.

     The Cassini orbiter advances and extends the United States'
technology base with several innovations in engineering and
information systems.  Whereas previous planetary spacecraft used
onboard tape recorders, Cassini pioneers a new solid-state data
recorder with no moving parts.  The recorder will be used in more
than twenty other missions both within and outside NASA.

     Similarly, the main onboard computer that directs operations
of the orbiter uses a novel design drawing on new families of
electronic chips.  Among them are very high-speed integrated
circuit (VHSIC) chips developed under a U.S. government-industry
research and development initiative.  Also part of the computer
are powerful new application-specific integrated circuit (ASIC)
parts; each component replaces a hundred or more traditional
chips.

     Elsewhere on the Cassini orbiter, the power system benefits
from an innovative solid-state power switch being developed from
the mission.  This switch will eliminate rapid fluctuations
called transients that usually occur with conventional power
switches, with a significantly improved component lifetime.


Huygens Titan Probe

     The Huygens probe, supplied by the European Space Agency,
carries a well-equipped robotic laboratory that it will use to
scrutinize the clouds, atmosphere, and surface of Saturn's moon
Titan.

     Released by the Cassini orbiter in late 2004, the Huygens
probe will drop into Titan's atmosphere some three weeks later.
As the 2.7-meter-diameter (8.9-foot) probe enters the atmosphere
it will begin taking measurements in the haze layer above the
cloud tops.  As it descends -- first on a main parachute and
later on a drogue chute for stability -- various instruments will
measure the temperature, pressure, density, and energy balance in
the atmosphere.

     As the Huygens probe breaks through the cloud deck, a camera
will capture pictures of the Titan panorama.  Instruments will
also be used to study properties of Titan's surface remotely --
and perhaps directly, should the probe survive the landing.

     Many scientists theorize that Titan may be covered by lakes
or oceans of methane or ethane, so the Huygens probe is designed
to function even if it lands in liquid.  If the battery-powered
probe survives its landing, it will relay measurements from
Titan's surface until the Cassini orbiter flies beyond the
horizon and out of radio contact.


Cassini Orbiter Experiments

     -- Imaging science subsystem:  Takes pictures in visible,
near-ultraviolet, and near-infrared light.

     -- Cassini radar:  Maps surface of Titan using radar imager
to pierce veil of haze.  Also used to measure heights of surface
features.

     -- Radio science subsystem:  Searches for gravitational
waves in the universe; studies the atmosphere, rings, and gravity
fields of Saturn and its moons by measuring telltale changes in
radio waves sent from the spacecraft.

     -- Ion and neutral mass spectrometer:  Examines neutral and
charged particles near Titan, Saturn, and the icy satellites to
learn more about their extended atmospheres and ionospheres.

     -- Visual and infrared mapping spectrometer:  Identifies the
chemical composition of the the surfaces, atmospheres, and rings
of Saturn and its moons by measuring colors of visible light and
infrared energy given off by them.

     -- Composite infrared spectrometer:  Measures infrared
energy from the surfaces, atmospheres, and rings of Saturn and
its moons to study their temperature and composition.

     -- Cosmic dust analyzer:  Studies ice and dust grains in and
near the Saturn system.

     -- Radio and plasma wave science:  Investigates plasma waves
(generated by ionized gases flowing out from the Sun or orbiting
Saturn), natural emissions of radio energy, and dust.

     -- Cassini plasma spectrometer:  Explores plasma (highly
ionized gas) within and near Saturn's magnetic field.

     -- Ultraviolet imaging spectrograph:  Measures ultraviolet
energy from atmospheres and rings to study their structure,
chemistry, and compositon.

     -- Magnetospheric imaging instrument:  Images Saturn's
magnetosphere and measures interactions between the magnetosphere
and the solar wind, a flow of ionized gases streaming out from
the Sun.

     -- Dual technique magnetometer:  Describes Saturn's magnetic
field and its interactions with the solar wind, the rings, and
the moons of Saturn.


Huygens Probe Experiments

     -- Descent imager and spectral radiometer:  Makes images and
measures temperatures of particles in Titan's atmosphere and on
Titan's surface.

     -- Huygens atmospheric structure instrument:  Explores the
structure and physical properties of Titan's atmosphere.

     -- Gas chromatograph and mass spectrometer:  Measures the
chemical composition of gases and suspended particles in Titan's
atmosphere.

     -- Aerosol collector pyrolyzer:  Examines clouds and
suspended particles in Titan's atmosphere.

     -- Surface science package:  Investigates the physical
properties of Titan's surface.

     -- Doppler wind experiment:  Studies Titan's winds from
their effect on the probe during its descent.


THE INTERNATIONAL TEAM

     Hundreds of scientists and engineers from 14 European
countries and 32 states of the United States make up the team
designing, fabricating and flying the Cassini-Huygens spacecraft.

     In the United States the mission is managed by NASA's Jet
Propulsion Laboratory in Pasadena, California, where the Cassini
orbiter is also being designed and assembled.

     Development of the Huygens Titan probe is managed by the
European Space Technology and Research Center (ESTEC).  ESTEC
will use a prime contractor in southern France, with equipment
supplied by many European countries; the batteries and two
scientific instruments will come from the United States.

     The Italian Space Agency is contributing the Cassini
orbiter's dish-shaped high-gain antenna as well as significant
portions of three science instruments.

     Communications with Cassini during the mission will be
carried out through stations of NASA's Deep Space Network in
California, Spain, and Australia.  Data from the Huygens probe
will be received at an operations complex in Darmstadt, Germany.

     At JPL, Richard J. Spehalski is Cassini project manager.
Dr. Dennis Matson is Cassini project scientist.

                              #####

     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | If you don't stand for
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/  |_|/       |_____|/                     | for anything.

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

Date: 15 Feb 93  12:35:20
From: [e-mail]
Subject: Daniel S. Goldin
Newsgroups: sci.space

        The California Space Development Council, a federation
of chapters of the National Space Society, has announced its
support of Daniel S. Goldin as Administrator of the National
Aeronautical and Space Administration (NASA). It also announced
its support of Goldin's reforms of the space agency.
        President Clinton has not yet announced his decision as to
whether Goldin will remain as Administrator of NASA. CSDC urges
everyone interested in the future of NASA and the nation's space
program to write Bill Clinton, Al Gore, their Congresspersons and
Senators in support of Daniel Goldin *immediately*.


--- Maximus 2.01wb

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

Date: Tue, 16 Feb 1993 14:17:07 GMT
From: Daniel Burstein <[e-mail]>
Subject: flashlights aboard the shuttle?
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Bruce Watson) writes:

>In article <[e-mail]| [e-mail] (Frank Reid) writes:
>|What kind of flashlights are used aboard the shuttle?  Are there
>|special NA$A $pace-qualified fla$hlight$, or do they use
>|something more mundane?
>|
>There is a picture of a penlight on page 2.20 of _The Space Shuttle
>Operators Manual_, Joels, Kennedy, Larkin, Ballantine Books, NY, 1982,
>IBSN 0-345-03021-0. It looks very much like those mundane mini-lights that
>are made by a number of manufacturers except that there is a band
>of velcro hooks (if you need a flashlight you need to know where it is.)
>and the paint has been stripped off (The paint on one of mine has
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>chipped off in places. I hope those chips didn't make it into my
>floppy drive.)

>NASA tries to use off-the-shelf components when possible
>and adapt them to Shuttle conditions, but if nothing commercial exists
>they've go to spend the money to build it.

>--
>Bruce Watson ([e-mail]) Bulletin 629-49 Item 6700 Extract 75,131

Since the shuttle (and Skylab, etc) are sealed environments (by normal
human standards...) NASA is -very- concerned about "outgassing".  Quite a
few common materials have this property, and while it might not be an
issue in the normal Earth-based environment, even minute amounts of some
of these things can rapidly become an issue up there.

Paints could very easily be a problem in this regard, so it is quite
possible they sanded it off.

[e-mail]

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

Date: 16 Feb 1993 16:43 UT
From: Ron Baalke <[e-mail]>
Subject: Life on Saturn
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Peter T.) writes...
>Recently a friend of mine asked me if I know anything about
>life on Saturn {no not interdimensional garb}. Apparently a
>friend of a friend of .......   , said something about life being
>found on Saturn and heard it on the local news.
>
>Correct me if I'm wrong but if I remember correctly, Voyager 2
>detected organic molecules in Saturn's upper atmosphere or
>in one of it's rings, and I concluded that thats what this is all
>about.

No life has been detected on Saturn, nor anywhere else in the solar system
outside of Earth.  Organic molecules were detected by Voyager in the
atmosphere of Titan, the largest moon around Saturn.  Even though the
surface of Titan is obscured by its dense atmosphere, it is a very
tantalizing object.  So much so that Titan was chosen over Saturn as
to where the probe in the Cassini mission will be dropped off at.
One of Voyager 1's main objectives at Saturn was to make a close flyby of Titan.
Had Voyager 1 failed from some reason, then Voyager 2 would of been directed
towards Titan and would of been unable to have gone on to Uranus and
Neptune.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | If you don't stand for
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/  |_|/       |_____|/                     | for anything.

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

Date: 16 Feb 1993 16:49 UT
From: Ron Baalke <[e-mail]>
Subject: Mars observer arrival
Newsgroups: sci.space

In article <[e-mail]>, Andrew Todd Weinstein <[e-mail]> writes...
>
>I calculated when the Mars Observer will get to Mars, I did
>42,000,000 km from Mars divided by 18,000 km/hour and then divided that
>by 24 hours to get the number of days, and it came out to be 97 days
>from Mars.  Is this a valid calculation or does the speed of the
>observer change periodically?

Mars Observer will arrive at Mars this coming August.

>Also, when it gets there does anybody know if it will be taking better
>pictures of the enigmatic Cydonia region of Mars than the previous
>viking explorer in the mid 70's?? I am sure if it is that with the
>higher resolution, it will be definite whether the mysterious objects at
>the Cydonia region of Mars are artificially formed or naturally formed,
>don't you think??

Mars Observer will be mapping the entire planet at higher resolution
than the Viknig Orbiters, so yes we will be getting better images of
the Face on Mars.

>If the formations at Cydonia are shown to be artificially formed then it
>could be the biggest discovery ever in all of history, and I guess this
>will be found out in only 3 months from now.  I think 1993 will be a
>very interesting year.

After orbit insertion, Mars Observer will perform seven maneuvers to
adjust its orbit and do a thorough checkout of all of its subsystems, so
it won't start mapping until the Dec 1993/Jan 1994 time frame.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | If you don't stand for
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/  |_|/       |_____|/                     | for anything.

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

Date: 16 Feb 93 11:03:54 +0600
From: [e-mail]
Subject: NASA Select
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (John Roberts) writes:
>
> Does anybody know what's going on with NASA Select lately? They provide
> a schedule stating that their programming will be repeated at midnight,
> then when midnight comes around, there's nothing but a schedule of the
> next day's programming, and a scrolling message stating that they replay
> their programing at midnight. Are they actually showing any programming
> during the day? Are they possibly having equipment problems, so that they have
> to work on their equipment at night?
>
> This policy is particularly troublesome to me because the local cable
> company mainly provides NASA Select on a local access channel after midnight.
> I believe several other cable companies do this as well.
>
> Did anything ever come of the discussion of an address to send email to
> provide input to NASA Select programming? I'm generally very much in favor
> of NASA Select, so when they don't bother to broadcast, it's discouraging.
>
> John Roberts
> [e-mail]

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

Date: 16 Feb 93 11:08:29 +0600
From: [e-mail]
Subject: NASA Select
Newsgroups: sci.space

John,
You can reach Pete Satterlee of NASA Select at 202-453-1199.  I
was unable to reach him this morning to find out about the problems
you were experiencing with Select, but he will be able to help you.
Tricia Porth
[e-mail]


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

Date: 16 Feb 93 16:44:32 GMT
From: "Kieran A. Carroll" <[e-mail]>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
> >If this claim is based on recent discussions here regarding
> >the change-over from the rectangular assemble-in-space truss
> >to the hexagonal pre-integrated truss, then I think that you're
> >way off the mark.
>
> As to the changeover to the pre-integrated truss...
> ...this change was mandated
> by Congress and not NASA who wanted the truss which didn't work (but kept
> Shuttle crews busy). Yet this change from an unbuildable truss to a
> buildable one is decried as micromanagement by Congress.

The change to PIT came about during NASA's ``90-day'' SSF re-design workshop.
To the best of my knowledge, Congress' main input to that process was to say,
``You remember how much money we said last year that you could have to build
SSF? Well, now we've decided that you can't have that much, which puts your
current design way over our revised budget. Bad management on your part!
Fix it!'' Previous scrubs to the design had involved incremental changes to
the dual-keel concept; I for one had expected a similar result from this one.
The scope of the changes that came out of the workshop were quite surprising,
although they made sense in light of the Fisher-Price report that had come out
a few months before the workshop started.

When NASA initially selected the box-truss concept, it seemed to make sense. A
design was developed based on this concept; during the process of development,
problems were found with the concept. The truss was not ``unbuildable''; the
ACCESS/EASE experiments on the shuttle show that if anything the SSF truss
would be >easier< to build than initially thought. The real problem was in
another area---maintenance would require more time than anyone had thought,
and adding time to the maintenance budget required time to be taken from other
budgets. The only sufficiently-large reservoir of time was that to build the
truss and hook up its utilities; by changing over to PIT, the truss-building
time budget was raided to augment the maintenance time budget.

> ...This still ignores the total lack of integration testing and huge
> unknowns about our ability to assemble things in space...

No, there will be integration testing at various levels. They won't build the
entire structure on the ground and hang it from wires; is that what you mean?
As spacecraft get larger, pre-integration of the entire structure before
launch eventually has to be foregone; SSF will teach us a lot about how to do
this. As for assembling things in space, much has been learned in water-tank
practice sessions, and subsequently validated by carrying out corresponding
experiments in orbit. Sure, plenty of unknowns remain, but a >lot< of work is
being done right now on illuminating these areas of darkness.

> Those of you who think ending Fred will be an end to manned space, think
> about this. What happens if Fred simply can't be built because of the
> lack of integration testing and poor EVA practice our astronauts receive?

I guess that people who oppose SSF, and especially people who oppose manned
spaceflight, will certainly get a warm feeling from indulging in this fantasy.

(regarding the systems design approach)
> My experience is that it only works
> when the requirements are well understood and there is a single project
> manager (like von Braun for Apollo) who keeps track of the whole thing.
> None of these conditions hold for Freedom.

Von Braun worked on Saturn. I believe that Joe Shea was the NASA manager that
pulled off the Apollo miracle. However, I will agree with this point.

> Saturn received lots of integration testing and each component
> received realistic tests working with the other modules of the system.
> None of this applies to Freedom.

Come off it! >Plenty< of testing will be done on the ground. For the
ground tests in which I'm involved (space-to-ground antenna dynamics), the
only objection is that they're probably going to be too severe! Tell me
this---as far as you're concerned, how much testing is enough? testing is a
way to manage risk, in order to keep budgets reasonably low; if you specify
too-ambitious a test program, then schedule and budget will balloon to the
point that the customer will rebel. As for the Saturn example, many engineers
on the program were very upset at the >lack< of integrated testing in the
program plan---remember ``all-up testing''? i.e. testing by flying the entire
vehicle, rather than flight-testing each stage in turn. The design was good,
and the vehicle flew. Many of the organizations involved in SSF were also
involved in Saturn and Apollo; why should their SSF designs be any worse than
those of earlier projects?

> Freedom never had a clear cut set of requirements (unless you consider
> 'be everything for everybody' clear cut)...

SSF had clear-cut requirements. In retrospect, they were too ambitious, and
have since been scaled back.

> >To characterize this as "covering up" seems absurd; >every< engineering design
> >has many intermediate design problems and issues (including Apollo, and the
> >design of whatever car that you drive); as long as the problems are
> >dealt with (even if it takes some time to do so, due to the complexity
> >of the system being designed), then why should anyone outside of the design
> >organization want to know about these issues?
>
> If that where the case, I would have no problems. The problem is that we
> only seem to see corrective action taken when outside agencies mandate it.
       ^^^^

Perhaps that's the key: ``seem''. People >in< the program see corrective
action being taken all the time, in response to problems of varying magnitude.
People >outside< the program only see the major changes, generally very large
changes that come about as a result of Congress changing their collective mind
about how much they want to spend.

--

     Kieran A. Carroll @ U of Toronto Aerospace Institute
     uunet!attcan!utzoo!kcarroll [e-mail]

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

Date: Tue, 16 Feb 1993 16:10:58 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas Clarke) writes:
>In article <[e-mail]> [e-mail] (Kieran A.
>Carroll) writes:
>>
>> Regarding my "off the mark" contention, I wonder if you understand
>> the systems engineering approach that is being used to design
>> SSF (and whish was also used on Apollo, and most NASA programs
>> since then). In that approach, design is carried out  by a
>> hierarchy of organizations/departments, organized in a tree
>> structure---one group at the top (NASA Level II), and many
>> groups at the bottom (i.e. at the "leaf nodes" of the tree).
>>
>> ... Intersting, but long explanation deleted.
>>
>Thank you for the explantation.
>
>I can only say AMAZING!!!
>There is no one in charge!!
>No one at the top seems to have the knowledge/information to
>make better than order of magnitude guess's as to what things
>are going to cost.
>
>The people at top have to deal with political realities such as
>that they can get X $billion from US Congress to build Fred.
>
>They then specify (on what basis?) that they want Y cubic meters
>of experiment space, Z kilowatts of power, etc.
>
>They then invoke systems engineering and after everything
>goes down the tree and back up after an expenditure of probably
>X/2 $billion for detailed design, they discover that Fred with
>Y and Z capabilities will cost $4X >> X.
>
>So they revise Y and Z downward and invoke systems engineering
>all over again.  At what cost?  Will the revision be enough?
>
>AMAZING!!!  No wonder NASA has problems.  Someone at the top
>has to be smart enough to juggle the realities of X $ versus the
>engineering constraints on Y and Z before spending $X/2 billions.
>
>Is Goldin that man?

No. And neither were those gods on Earth Werner von Braun or
Kelly Johnson. Fred is simply the most complex aeronautical
engineering exercise ever attemptedi out of whole cloth. No
one man could hold all the variables in his hands *before*
detail design work was accomplished by those lower down the
tree. Lot's of the variables are *unknown* until that preliminary
design is done. Any revisions generate new sets of unknowns. It's
necessarily an iterative process.

One could argue that Fred is too ambitious at our current
state of knowledge. We tried to leapfrog the Russians by
jumping straight from Skylab to Fred while they've plodded
along with Salyuts and Mir until they are now ready for
a truss based Mir II. This has been typical of the two
programs, we occasionally wake up and try to make heroic
leaps while they just plod along like the tortoise and
the hare.

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: 15 Feb 93  12:05:10
From: [e-mail]
Subject: Privatization of space s
Newsgroups: sci.space

CM>What would happen if a prospective space-services company were to appr
CM>governments of the world an offer to bring back a bucket of Mars dirt,
CM>with other samples and measurements, to the highest bidder?
CM>
CM>Would agencies like NASA and ESA oppose such private-run operations?
CM>they be happy to buy the product--if the offered price were less than
CM>could match?
CM>
CM>Is there entrepreneurial potential in such projects?

Is this good enough?

      Lunar Resources Data Purchase Act
   "Back to the Moon Bill"
-
 The Lunar Resources Data Purchase Act is a bill to encourage
the development of a commercial space industry in the United
States, and to regain the leadership of the United States in the
field of lunar science.
-
     Executive Summary
-
 The Lunar Resources Data Purchase Act authorizes the U.S.
government to purchase lunar science data from commercial and
non-profit suppliers, selected via competitive bidding.
 This and future science surveys of the Moon will be conducted
similarly to the aerial photography surveys of the continental
U.S. managed by the U.S. Geological Survey since the late 1930's.
NASA has also recently begun to purchase space science from the
private sector, under the SeaWIFS program. As the Congress of the
United States creates requirements in the future for data from the
Moon, the acquisition of the data will be conducted under the
authorization within the Lunar Resources Data Purchase Act.
 Furthermore, the Lunar Resources Data Purchase Act contains
an initial  authorization for a survey of the lunar surface for
elemental and mineralogical content, including the polar regions.
Once funding for this survey is authorized and appropriated, bidders
will be evaluated on the basis of price, instrument resolution, and
time to survey completion, under the current Federal Acquisition
Regulations (FAR).
 The last dedicated U.S. mission to the Moon was Apollo 17,
launched in December, 1972.  To date, most available lunar data
is of the regions of the lunar equator. Some scientists believe
there is possible water ice in deep craters at the lunar poles,
but the available data, including recent Galileo imagery and
data to be obtained from the future SDIO Clementine program,
cannot resolve this issue.
 Whether or not the Moon is a suitable area for future human
exploration, it would be foolhardy to not explore it robotically
for resources such as water ice that, if available, would make
human exploration of the Solar System more economical and safe.

 A briefing book on the bill, which includes the first draft,
is now available to those who furnish a mailing address. For more
information, please call 714/524-1674 (David Anderman), 619/295-3690
(San Diego L5) or 310-364-2290 (OASIS), or forward E-Mail via
Internet to: [e-mail]



___ WinQwk 2.0b#0


--- Maximus 2.01wb

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End of Space Digest Volume 16 : Issue 192
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