Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO305.TXT

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Date: Fri, 12 Mar 93 05:39:10
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #305
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 12 Mar 93       Volume 16 : Issue 305

Today's Topics:
              ***  The Shuttles 5 computers. INFORMATION
                        20Khz Power supplies.
                           Charon (2 msgs)
                         Lunar Ice Transport
                    Moons rotation period question
                      My DCX .sig and DCX update
         Student Design Project (was Re: Lunar Ice Transport)

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Date: 12 Mar 1993 01:41:56 -0500
From: Pat <[e-mail]>
Subject: ***  The Shuttles 5 computers. INFORMATION
Newsgroups: sci.space

I would look into TANDEM computers hardware and
Stratus Computer Systems.  They dominate the
fault tolerant world.

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

Date: 12 Mar 1993 01:33:32 -0500
From: Pat <[e-mail]>
Subject: 20Khz Power supplies.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>In <[e-mail]> [e-mail] (Pat) writes:
>
>>In article <[e-mail]> [e-mail] (David B. Mckissock) writes:
>>>In article <[e-mail]>, [e-mail] (Pat) writes...
|>>>
|>>>Unless you were some sort of demi-god there,  don't expect to
|>>>hear every story in the program.
|>>I worked in a System Engineering organization at the time,
|>>and our job was to help pull together the *ENTIRE* story
|>>concerning the SSF power distribution frequency. We
|>>worked closely with the other work packages, the Internationals,
|>>and Level II. It was our job to hear *EVERY* part of the story
|
|>There were still numerous people in Management whose job was to
|>not hear problems, but to roll the schedule.
|
|So your contention here is that someone who was there and cognizant
|must know less than someone like you who was not?  This logic is as
|interesting as that of 'anonymous poster' about how it takes more
|courage to *not* be associated with what you say.
|

I never said I was there.  I said, I had friends at Reston who
were very frustrated with the management structure and attitude.
These were guys who told me in 1988, the "Damn thing is not meant
to fly".

I don't have to smoke crack to think it's stupid?  why should I
have to work at NASA to know this project was out of control.

|>>relative to the decision. My guess is that your Reston
|>>contact was outside the loop on the 20 kHz decisions, and
|>>heard spurious rumors.
|>><< Discussion attacking 20 kHz deleted >>
|
|>Not how you avoid a very resaonable discussion on how STUPID
|>the 20 KHz idea even was in the first place?
|

NOTE AGAIN:  No-one at NASA or in SSF contract staff has yet
to come up with one reasonable discussion supporting the idea
of 20Khz power.

|>Can you name any competent Electrical engineers, or Computer engineers
|>or PE's  who thought this was a good idea?
|
|Gee, Pat, do you think an accountant dreamed it up, or what?

Yes.  The idea is obviously more oriented at enriching contractors
then at producing working systems.


|Obviously there were some engineering folks who thought it *might* be
|a good idea, or it would never have been investigated in the first
|place.  This is how engineering works, Pat.  You look at various
|possible solutions to the problem, analyse the risks, costs, and
|benefits, and then you pick the one that seems best overall.
|

Yeah, and look at the decision they picked.   They picked Most Risk,
Most Cost, Fewest Benefits.  No-one disputes this.

If the decision making process makes this kind of obvious error,
what makes you think they aren't screwing up elsewhere.

Engineering is a highly conservative field.   It doesn't do things
because it sounds nice,  it does things because it works.  And 20Khz
never worked even on paper.


|>Given how bad the concept of 20 KHz was,  why do you expect me to believe
|>the studies on it's safety.
|
|Because he was there and you weren't?  This starts to sound more and
|more like a "my mind is made up -- don't cloud the issue with facts"
|position on your part.
|

And maybe my friend at Reston was "There" and had a manager tell him
"Don't worry about the safety study, the station will never fly".


|>Name 5 advantages to 20 KHz.  I dare you.
|
|Gee, now *there* is an adult discussion.  Hey, see if you can find
|some and broaden your own mind.  I *double* dare you!
|

Here are a few:

1)  Enrich Boeing, McDac and GD.

2)  Ensure the astronauts have plenty of work to do replacing
    blown out electrical gear.

3)  Ensure the jobs of a lot of NASA people, because it imposes more
    restrictions on the science platforms.

|>Name 5 disadvantages to 20 KHz.  Compare and assess these.
|
|>Now justify all the money spent on the 20 KHz power project.
|

Note how no-one from NASA or the SSF contractor community dares
discuss the engineering decisions on the SSF.

|>>
|>>>Sorry, quoting some rag of documentation doesn't impress me.
|>>The 'rag' of documentation I quoted from is the Program
|>>Definition and Requirements Document, referred to as the
|>>PDRD or SSP 30000. For anyone working on SSF, this document
|>>*IS* the Holy Bible.
|>>
|
|>BIG DEAL.
|>The system requirements document.  I've seen requirements documents
|>on lots of projects.  ANd if the document is poorly done, it doesn't
|>matter.  If the people doing the work don't care about quality
|>it doesn't matter.
|
|>It's just more paper and vapor.  You guys have spent a lot of money,
|>and don't have much product to show.
|
|Once again, you seem to think you know better than someone who was
|there and has seen the things.  That's not to say that there aren't
|problems; I would say there most certainly are, from what I've seen.
|However, I think you'd be better served to address the problems
|instead of random flames.
|

Hey, I have friends there.  And look at skylab.  THey didn't have a
"HOLY BIBLE".  They had a chief engineer who was Great, and they
had a hard budget and they made the bird fly, in slightly uunder a year.

Given the delays on SSF, it is likely SKYLAB will have more flight hours
then SSF this century.

|>>You obviously don't understand how NASA operates. For the SSF
|>>program, NASA has three Contractors responsible for building
|>>SSF hardware (McDonnell Douglas, Rocketdyne, and Boeing). A
|
|>And who is responsible for integrating their work?  How come
|>that's a major management issue?
|
|Bingo!  Real problem #1.
|

And why is it that 10 years into the program, they are finally addressing
a vital up-front problem?

|>>At each design review, the Contractor must provide evidence
|>>that their design meets each and every requirement. In
|
|>And how rigorous does that evidence have to be?  do any
|>PE's stamp off  the designs?
|
|I would say that, in general, no.  Who made a PE ghod?  There are lots

In general, Judge Wapner.   What most CS people don't understand is that
a PE takes LEGAL responsibility for all work done under his stamp.
PE's like most other licensed professionals is Criminally responsible
for any failures that cause loss of life,  as well as bearing a personal
liability for any civil losses.

PE's have done time for people dying, and many of them are sleepless
over things they signed off.   Nobody at NASA or the Contractors is
responsible if something fails on SSF.



|of good engineers who simply can't be bothered with it, since it is
|only in things like structural engineering that it becomes
|particularly meaningful.  I've always found it funny that, except for
|stuff that delivers to the government (which follows more reasonable
|rules about who is an 'engineer'), I would have to get a PE to sign
|off on a software system when there is no such thing as a PE for
|software engineering.  What that means is that someone who is
|specialized in a different field has to sign off on the software.
|Does this strike you as ridiculous?
|

no.  it means someone is willing to lose his license over the quality
of your work.  If software is going to be "Engineering"  then it
better have standards and ethics, and responsibility.

|>>any areas where the design doesn't meet the requirement, a
|>>deviation or a waiver must be processed.
|>>
|>Or a smoke cloud is generated.
|
|>>This whole area of requirements verification is treated
|>>very seriously.
|
|>As serious as the budget over-runs?  i don't think so.
|
|Then you've never been through a requirements audit.
|

Sure, I've been through them, and i've also worked on projects where
the people just kept puffing smoke as opposed to fixing problems
because they wanted to suck off the governments tit.
I've taken heat from management for refusing to sign off on
smoke requirements checklists.

|>Basic engineering criteria and design decisions were made for SSF
|>on fatally flawed reasoning.  all the paper in the world won't
|>make up for those mistakes.
|
|>I dare you to justify 3 things:
|
|Man, I can't tell you how impressed I am with such adult discussion as
|"I dare you".
|

I still don't see mcKissock willing to defend his ideas.

|>    1)  20 KHz power developement.
|
|If you never consider anything new, you continue to build yesterday's
|systems.
|

Gee.  How come my desk lamp is still 60Hz.  That's yesterdays system.
But, It Works!  How come my car is a diesel?  It works!  Why are
houses still built of wood and stone?  they work!  Engineering is based
upon using known solutions.
New ideas are extensively tested infield trials before use in production.

|>    2)  Non Metric (english)  component selection with the
|>    european modules being Metric.
|
|Why should it be metric?  The bulk of the funding is from the United
|States of America -- and we're not on the metric system.  Why not just
|require everyone else to build non-metric to match the main station?
|

Gee, what a great defense.  It's my bag of marbles, i make the rules,
even when my rules are costly and silly,  And given it's an
international station,  we have limited influence on the design of the
japanese and european modules.  They do much of their own work.
In fact, one of my reston contacts was involved in trying to get the
freedom team to switch to metric sizing on fasteners and connectors.
management wouldn't allocate a few million dollars to pay for
costs for this.

|>    3)  Total failure to practice EVA until this year.
|
|Fear of 'adult' critics like you who would flip out over the costs and
|risks of 'unnecessary' EVA's.
|

Gee.  I'mm so glad they listen to me.


Goldin gave a speech this week, he was tired of NASA's existing mentality
and of hearing stories of the apollo age.  He said we have to write
history not read it.  It also looks like he is inviting the russians
to participate in SSF.

pat

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

Date: Fri, 12 Mar 1993 03:23:05 GMT
From: Mike Van Pelt <[e-mail]>
Subject: Charon
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>In article <[e-mail]>, [e-mail] (Arthur Chandler) writes...
>>  In the event of a Pluto flyby, I gather that there will be data
>>gathered about Charon. If photo images are recorded, what will be the
>>approximate resolution of detail on the surface of Charon?
>
>At least 1km/pixel resolution.

Speaking of Pluto imaging, a couple of years ago someone was supposedly
recording the brightness fluctuations of the Pluto-Charon system while
Charon and Pluto were occulting each other, and they were going to
analyze the data in order to produce an image.

Am I misremembering?  Did anyone do this?
--
"The American Republic will endure, until        Mike Van Pelt
politicians realize they can bribe the people    [e-mail]
with their own money."  Alexis de Tocqueville

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

Date: Fri, 12 Mar 1993 07:43:51 GMT
From: Dave Tholen <[e-mail]>
Subject: Charon
Newsgroups: sci.space

Mike Van Pelt writes:

> Speaking of Pluto imaging, a couple of years ago someone was supposedly
> recording the brightness fluctuations of the Pluto-Charon system while
> Charon and Pluto were occulting each other, and they were going to
> analyze the data in order to produce an image.
>
> Am I misremembering?  Did anyone do this?

You are not misremembering.  Somebody did do this.  Look in Icarus, volume
97, page 211 (1992).

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

Date: 12 Mar 93 02:42:18 GMT
From: Philip Young <[e-mail]>
Subject: Lunar Ice Transport
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Ross  Borden) writes:
|>
|>     In all the Lunar ice transportation proposals that I've seen,
|> nobody has mentioned what would be, on Earth, the most obvious: overland
|> hauling.

The proposed lunar tractor/trailer, plus road engineering, would be
incredibly expensive.  A polar rail gun avoids all the problems with
surface transportation.  Accuracy would be great in vacuo, and you can
charge up the capacitors with plentiful, cheap, solar power.  Even
during lunar winter, you could beam power from a satellite, or operate
the other pole.

Designing an equitorial catcher's mitt could be a challenge, though.

--
Philip R. Young
Data General Australia Pty. Ltd.


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

Date: 12 Mar 1993 05:10:26 GMT
From: Aaron Ray Clements <[e-mail]>
Subject: Moons rotation period question
Newsgroups: sci.space

[e-mail] (Aaron Ray Clements) writes:

>[e-mail] writes:

>>I have a question.
>>Why does the Moon's rotation period exactly match its
>>revolution period such that it always presents the
>>same face to the Earth? (...and we end up with a
>>darkside.)  What is the physical mechanism that
>>has caused this?
>>Is this common for moons around the solar system?

>>-Bret-

>This is actually a relatively common feature of planetary
>geology and is referred to as tidal locking.  The force
>of gravity exerted by the earth on liquid portions of the
>moon (i.e., tides) is expended against the solid portions,
>slowing the rotation period.  This happened on the moon
>considerably in the past (during its cooling period, though
>with a liquid core it still happens to some extent.)

>This mechanism is the same reason that the earth's rate of
>rotation is declining; the tides caused by the moon act
>on earth's oceans and seas; this force is transferred to
>the surface by the tidal action (and is particularly effective
>in narrow, shallow sea beds where the gravitaional force on
>the water can be transferred more efficiently to the earth's
>solid crust).  Conservation of angular momentum then dictates
>that the moon must absorb the momentum lost by the earth;
>the moon therefore moves farther away from the earth.  The
>moon will continue to recede until the earth is tidally
>locked with the moon.

>Note that this applies to bodies that are in part fluid.  I
>believe it is rather difficult for solid bodies (eg Phobos
>or Deimos) to become tidally locked.

>Hope this helps.

>aaron
>[e-mail]


A correction to the above:  the moon's core is not now liquid
(if it were, the moon would have a significant magnetic field).
My apologies for the error, and my thanks to Bill Gawne for
pointing it out to me.

The continuing lunar tidal locking (I think) is attributable to
the fact that lunar density is not uniform; this results in the
center of mass of the moon being offset from the geometrical
center, creating a gravitational differential across the moon
that serves the same purpose (but on a much smaller scale).

aaron
[e-mail]

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

Date: Fri, 12 Mar 1993 02:37:32 GMT
From: William Naylor <[e-mail]>
Subject: My DCX .sig and DCX update
Newsgroups: sci.space

Could somebody tell me what the "DCX" is?


--
Will Naylor               net:  [e-mail]
                          mail: Canon Information Systems Research Australia
phone: [phone]          P.O. Box 313 North Ryde, NSW 2113
fax:   [phone]          Australia

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

Date: 11 Mar 93 20:21:04 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Student Design Project (was Re: Lunar Ice Transport)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Ross  Borden) writes:
> In article <[e-mail]> [e-mail] (Bill Higgins-- Beam Jockey) writes:

>>The project's assumptions include:
>>
>>1. A source of water ice at the poles of the Moon.
>>[This is scientifically plausible; evidence does not yet rule it out.]
>>
>>2. It must be moved to a lunar base at the lunar equator for
>>processing into rocket propellant (and perhaps other useful
>>products?). [This is completely senseless; obviously the processing
>>should be done at the poles, near the "ice mines."]

>     If you had an established base at the equator with
> permanent housing, life support and power for a large number of people,
> and, presumably, industry and research for them to do there, and THEN
> discovered ice deposits at the poles, it might be reasonable.

I don't think so.  This level of development implies considerable
capability to land equipment on the Moon.  And you want to take dirty
frozen stuff and turn it into hydrogen and oxygen.  That takes
materials-handling gadgets and power.  It is much simpler to establish
a second base near the polar ice deposits, set up solar panels and
processing plants, and produce propellants there.

Taking it 1300 kilometers requires a larger investment in hardware and
people, in my opinion, than setting up a factory *in situ*.  Look at
the alternatives:

1. THE ICE FLINGER: Rajesh Batra and John Papp and their friends  are
planning to build a giant electric catapult to throw the ice southward
(or northward) with enough speed to get to the equator and with enough
precision to land in a giant funnel.  This is pretty Rube Goldberg,
and they will earn my admiration if they can come up with a plausible
design.  Clearly they need to have not only a mining operation at the
pole, but a mass driver/railgun/whatever that's a substantial civil,
mechanical, and electrical engineering project, and a large source of
electrical power.  And they need to build the catcher near (maybe not
TOO near!) the equatorial base.  Will this be less expensive than
constructing the fuel factory at the pole?

It is also disturbing that they have to fling the ice with a fair fraction of
the delta-V they could get out of it by using it as rocket propellant... this
makes engineering sense, as the energy comes from a wall plug and does not
affect the usefulness of the ice.  But it sure lacks elegance!

2:  THE MULE TRAIN: Ross, you suggested the lower-tech route in your message
<[e-mail]>, with subject "Lunar Ice Transport."

>    To maintain high through-put, a continuous stream of vehicles
>would haul ice from the polar ice mines to the equatorial processing
>plants, and then dead-head back (unless there was some return cargo.)
>[...] It might be possible to string several
>'cars' together behind a 'locomotive'.
>    The only feasible power source would be nuclear.  Chemical would
>require too much fuel mass and solar would be useless in the long lunar
>night. [Then you suggest that the driving be automated.]

This is the way I would do it, if I were in the class, unless a study
of maps convinced me that there was no passable route.  (I'm sure the
Cincinnati studends considered it.)  I would toy with a railroad, too,
but probably reject it.  But this requires a fleet of well-engineered
vehicles large enough to handle the mine production, plus perhaps some
improvement of the route (blasting passes through highlands?), plus
maintenance bases and spares.

It's hard to believe that either of these alternatives, the Ice
Flinger or the Mule Train, will cost less than refining the ice at the
pole and using rockets to move propellant around.  You already have
designed, built, and tested the rockets for lunar transport, so you
can just build more.  Their operating costs will go *down* when you
get the plant going.  (I assume here, of course, that these are
rockets that can benefit from the production of ice, probably H2-O2
chemical rockets, possibly H2-fission. Otherwise the whole scenario is
bizarre.)  The entire lunar system cost will go up until ice
processing can pay for itself, but that is true for all the
alternatives.

Do you agree with me now, or can you refute these arguments?

>     Of course, we should know if there is ice at the poles long
> before we have a permenantly manned presence there.

You can rule out large (like ~1 km) deposits with a neutron
spectrometer on a small polar-orbiting spacecraft, good analysis
software, and patience.  (The hydrogen in the ice will "moderate" or
slow down the neutrons created by cosmic rays in the Moon's soil.)

Engineer of Hijacked Train:      Bill Higgins
"Is this a holdup?"
                                 Fermi National Accelerator Laboratory
Masked Gunman:
(Hesitates, looks at partner,    Bitnet: [e-mail]
looks at engineer again)         SPAN/Hepnet/Physnet: 43011::HIGGINS
"It's a science experiment!"     Internet: [e-mail]

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

End of Space Digest Volume 16 : Issue 305
------------------------------