Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO349.TXT

Internet Message Format | 1993-07-13 | 32KB

Date: Mon, 22 Mar 93 05:00:11
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #349
To: Space Digest Readers
Precedence: bulk


Space Digest                Mon, 22 Mar 93       Volume 16 : Issue 349

Today's Topics:
        Alumnium was available in Elizabethan times? (4 msgs)
                            COSMIC Catalog
                                 DC-X
                              Grand Plan
                      Magellan Update - 03/19/93
                   Mars Observer Update - 03/16/93
                     Need MIR packet Frequency's
                   QUICKTOP2-- Where can I find it?
               Semi-technical aspects of SSTO (repost)
                        Skysurfing from Orbit
                     SR-71 Maiden Science Flight
                 SSTO: A Spaceship for the rest of us
                            Subject Lines
                          Water Simulations
    Water Simulations (Was Re: Response to various attacks on SSF)
                  Why use AC at 20kHz for SSF Power?

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

Date: 21 Mar 93 14:01:57 GMT
From: Del Cotter <[e-mail]>
Subject: Alumnium was available in Elizabethan times?
Newsgroups: sci.space,sci.materials

In article <1ogckv$[e-mail]> [e-mail] (Pat) writes:
>Dennis, I dont think you know as much history as you may need.
>You should read James Burke's "Connections".  He traces how ideas move
>through time to affect technical innovation and the problems that force
>the movement of technology.
>
>First of all, things can't be done until the technical base exists to
>support it.  Aluminum was available in elizabethan times,  but the
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>costs of extraction made it more valuable then gold.  Now process
>improvements, make it cheap enough for sandwich wrap.

Tell me more :-)

Note Newsgroups: and Followup-To: lines.
--
 ',' ' ',','  |                                                  |  ',' ' ',','
   ', ,','    |       Del Cotter       [e-mail]      |    ', ,','
     ','      |                                                  |      ','

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

Date: 21 Mar 93 17:06:15 GMT
From: Steven M Bonneville <[e-mail]>
Subject: Alumnium was available in Elizabethan times?
Newsgroups: sci.materials,sci.space

In article <[e-mail]> [e-mail] (Del Cotter) writes:
>In article <1ogckv$[e-mail]> [e-mail] (Pat) writes:
...
>>support it.  Aluminum was available in elizabethan times,  but the
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>costs of extraction made it more valuable then gold.  Now process
>>improvements, make it cheap enough for sandwich wrap.
>
>Tell me more :-)


I don't know about Elizabethan times, but I recall hearing a story from an
old chemistry professor of mine that Napoleon Bonaparte owned a set of
aluminum tableware...before the invention of the electrolytic process that
makes extraction of aluminum reasonably cost-effective today.  I don't
remember the exact details, but the process which was previously used was
quite a bit slower and more difficult, making the aluminum that was
refined *extremely* expensive in any quantity.

[Note follow-up and newsgroups.]

--Steve Bonneville
<[e-mail]>

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

Date: 21 Mar 93 17:08:37 GMT
From: Steven M Bonneville <[e-mail]>
Subject: Alumnium was available in Elizabethan times?
Newsgroups: sci.materials,sci.space

In article <[e-mail]> [e-mail] (Del Cotter) writes:
>In article <1ogckv$[e-mail]> [e-mail] (Pat) writes:
...
>>support it.  Aluminum was available in elizabethan times,  but the
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>costs of extraction made it more valuable then gold.  Now process
>>improvements, make it cheap enough for sandwich wrap.
>
>Tell me more :-)


I don't know about Elizabethan times, but I recall hearing a story from an
old chemistry professor of mine that Napoleon Bonaparte owned a set of
aluminum tableware...before the invention of the electrolytic process that
makes extraction of aluminum reasonably cost-effective today.  I don't
remember the exact details, but the process which was previously used was
quite a bit slower and more difficult, making the aluminum that was
refined *extremely* expensive in any quantity.

[Note follow-up and newsgroups.]

--Steve Bonneville
<[e-mail]>

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

Date: Sun, 21 Mar 1993 18:40:53 GMT
From: Leigh Palmer <[e-mail]>
Subject: Alumnium was available in Elizabethan times?
Newsgroups: sci.space,sci.materials

In article <[e-mail]> Del Cotter, [e-mail]
writes:
>In article <1ogckv$[e-mail]> [e-mail] (Pat)
>writes:
>>Dennis, I dont think you know as much history as you may need.
>>You should read James Burke's "Connections".  He traces how ideas move
>>through time to affect technical innovation and the problems that force
>>the movement of technology.
>>
>>First of all, things can't be done until the technical base exists to
>>support it.  Aluminum was available in elizabethan times,  but the
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>costs of extraction made it more valuable then gold.  Now process
>>improvements, make it cheap enough for sandwich wrap.
>
>Tell me more :-)

According to my Rubber Bible, 63rd ed., Aluminum was first isolated in
1827 by Wohler. "Aluminium" is available in Elizabethan (II) times, and
perhaps "alumnium", whatever that is, was available in "elizabethan"
times, but aluminum was not available in Elizabethan times any more than
Macintoshes were.

This date also casts doubt on the story about Napolean's aluminum
tableware, if Bonaparte was meant, since he kicked the bucket in 1821.
My chemistry teacher told me the capstone of the Washington monument was
made of aluminum which was, at that time, considered to be a precious
metal. I've never checked that story out.

Leigh

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

Date: Sun, 21 Mar 1993 16:52:50 GMT
From: Scott Stallcup <[e-mail]>
Subject: COSMIC Catalog
Newsgroups: sci.space

  Could someone please post or mail me ordering information for
  NASA's COSMIC software catalog.    I need a phone number
  and/or address to order a copy.

  Thanks,

  -------------------------------------------------------------
  Scott Stallcup     ([e-mail])
  Space Telescope Science Institute

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

Date: 21 Mar 93 22:55:28 GMT
From: "John R. Manuel" <[e-mail]>
Subject: DC-X
Newsgroups: sci.space

Are there any articles in Aviation Week, or somewhere similar, about DC-X
that someone can refer me to? I'm curious to see the design of the thing
and in particular, how it will manage re-entry and still be re-usable.

-----------------------------------------------------------------------
---
John R. Manuel
[e-mail]
64-4-570-4024 (office)                           NIWAR Atmospheric
Division
64-4-566-6166 (fax)                                 Wellington, New
Zealand
-----------------------------------------------------------------------
---

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

Date: 21 Mar 1993 12:33:01 -0500
From: Pat <[e-mail]>
Subject: Grand Plan
Newsgroups: sci.space

I hope a very detailed audit was done on CRAF/Cassinnis contractors.
I remember rockwell screwed NASA out of a Billion dollars
during the STS developement.

pat

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

Date: 21 Mar 1993 12:27:16 -0500
From: Pat <[e-mail]>
Subject: Magellan Update - 03/19/93
Newsgroups: sci.space,sci.astro,alt.sci.planetary

can I get some of the surplus gear?

pat

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

Date: Sun, 21 Mar 1993 17:01:52 GMT
From: Steve Collins <[e-mail]>
Subject: Mars Observer Update - 03/16/93
Newsgroups: sci.space

It was pointed out to me that the transmitter power is less factor in the
differing up and downlink rates than the receiver antenna sensitivity.
The ground antennas can be very big...
      Steve Collins MO SCT (AACS)

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

Date: Sun, 21 Mar 1993 16:53:49 GMT
From: George Rachor <[e-mail]>
Subject: Need MIR packet Frequency's
Newsgroups: sci.space,rec.ham-radio.packet,rec.radio.amateur.packet

[e-mail] (Steve Ford) writes:
>Yep. 145.55 MHz. They tend to be a bit sporadic, so it takes a little
>patience. Good luck.

>73...Steve
>WB8IMY

Well... We heard it and my friend doug (Kb7RHF) attemted a packet connect....

Thanks everyone!

George Rachor

--
George Rachor Jr.    Aloha, OR

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

Date: Sun, 21 Mar 1993 16:09:23 GMT
From: Michael Robert Williams <[e-mail]>
Subject: QUICKTOP2-- Where can I find it?
Newsgroups: sci.space,sci.astro,alt.sci.planetary

The subject line says it all-- I've heard of a computer program called
QUICKTOP2 that is supposed to generate optimal spacecraft trajectories.
I think it's a NASA product, but I'm not sure. My question is Where can
I find it? ANd, if it's not available, can I find source code, technical
manuals, etc containing the algorithms used? Thanks in advance.

In Real Life:Mike Williams     | Perpetual Grad Student
e-mail      :[e-mail]|   - It's not just a job, it's an indenture
---------------------------------------------------------------------------
"If you ever have a world of your own, plan ahead- don't eat it." ST:TNG

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

Date: 21 Mar 1993 12:51:02 -0500
From: Pat <[e-mail]>
Subject: Semi-technical aspects of SSTO (repost)
Newsgroups: sci.space

We should put this into the FAQ.

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

Date: Sun, 21 Mar 1993 16:27:36 GMT
From: Robert Magee <[e-mail]>
Subject: Skysurfing from Orbit
Newsgroups: sci.space

I could use a little data on re-entry for a short story I am laboring on.

1) From low earth orbit, how much thrust would need to be generated to slow a
400 pound mass sufficiently to enter the atmosphere?

2) What is the optimum angle to enter the atmosphere with the Shuttle?

3) How deep into the atmosphere must the shuttle descend before the wings
generate sufficient lift to provide control?

Input is appreciated.  When I figure out how to uucode a case of beer, I'll
post it. ;^)

Thanks
Bobby Magee
[e-mail]

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

Date: 21 Mar 1993 12:30:03 -0500
From: Pat <[e-mail]>
Subject: SR-71 Maiden Science Flight
Newsgroups: sci.space

Has anyone considered which is more fun to ride along on while
running science gear?  I'd rather hop in the back seat of the 71
and run the science gear, as opposed to dangling in a balloon.

pat

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

Date: 21 Mar 1993 19:51:41 GMT
From: Dave Akin <[e-mail]>
Subject: SSTO: A Spaceship for the rest of us
Newsgroups: sci.space

In article <[e-mail]> Paul Dietz,
[e-mail] writes:
>Actually, there are large economies of scale in oxygen production and
>distribution.  Almost all of the cost of your compressed oxygen
>cylinder would be in the overhead of the infrastructure for delivering
>and filling the tank with oxygen, not in the oxygen itself.  Ullman's
>Encyclopedia has a diagram of the price of oxygen vs. rate of demand;
>it varies by more than an order of magnitude from small scale
>(compressed gas cylinders) to intermediate scale (LOX tankers) to
>large scale (dedicated cryogenic or PSA separation plants).
Actually, I think all of the arguments in this thread are
missing the point. In typical economic analyses of launch
systems, propellent costs are often ignored in the
preliminary stages as being within the noise level! The thing
that really drives the cost of a reusable launch vehicle is the
"refurbishment fraction": the fraction of the original cost of
the vehicle that you have to pay for refurbishing the vehicle
between flights. If you want to meaningfully talk about the
differences between the planning and the reality for the
shuttle, it'e the difference between a 160 hour (2 week, 2
shifts) turnaround between flights as originally planned and
the reality, which is probably closer to 800 hours of serial
time. (Don't quote that number as gospel, I'm estimating,
and if anyone has real numbers, I'd love to hear from you!)
The bottom line is that the refurbishment fraction for a
shuttle orbiter is approximately 10%; that is, it costs about
10% of the replacement cost of an orbiter to refurbish it
between flights.

What bothers me about the SSTO/SSX/DC-X enthusiasts (I
started to say "groupies", but didn't want to start a flame war
:-)  ) is that they are largely ignoring the whole point of
refurbishment. Indeed, many of the tales being told about
DC-X ("airline-type maintenance", etc.) are the same things
I heard in the early days of the shuttle program. Don't get me
wrong, I have a lot of friends at MacDac, and I really hope
DC-X works like a dream, but I think it's a real mistake to
go into a program assuming you can improve things by an
order of magnitude based on an assumption (implicit or
otherwise) that you're an order of magnitude smarter than
the guys who did it the last time...

As a reality check, X-15 operations tended to have a
refurbishment fraction of about 3%/flight. (If the shuttle
could make 3%, we wouldn't be having these arguments
about whether or not it's cost-effective!) I think it's a valid
argument to say that DC-whatever is going to have more
extreme aerothermodynamic and general flight loads than
X-15, and that there isn't the body of experience in flying
and maintaining VTOL rocket systems that there was at the
time in rocket-plane operations. Throw in modern
technology on the other side, and I would argue that DC-
downtheline will probably be lucky to have a 3% refurb
factor. That will make it an efficient and useful addition to
the world's launch vehicle fleet... but NOT the quantum leap
its supporters are promising. (And you may want to reflect
on what price the shuttle program has paid for up-front
promises it couldn't keep...)
All of this, of course, in my humble opinion...

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

Date: Sun, 21 Mar 93 17:24:21 EET
From: [e-mail] (F.Baube[tm])
Subject: Subject Lines

I don't want to take sides in the argument in question.

And irrelevant subject lines are endemic to this group.

But couldn't follow-ups at least modify condescending
subject lines like "Clueless Szaboisms" ?  Let the
condescension begin and end with the original poster ?

Thanks.

--
* May '68, Paris: It's   "[In conjunction] with the present means of
*  Retrospective Time !!  long-distance mass communication, sprawling
* * * * * * * * * *       isolation has proved [to be an] effective
* Fred Baube (tm)   *     method of keeping a population under control."
* [e-mail]   *   -- Lewis Mumford, "The City in History"

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

Date: 21 Mar 1993 19:34:39 GMT
From: Dave Akin <[e-mail]>
Subject: Water Simulations
Newsgroups: sci.space

In article <[e-mail]> Bruce Dunn, [e-mail]
writes:
>        I once again offer my suggestion of a neutral buoyancy simulator
>using pentane rather than water for buoyancy.  Pentane has only a small
>fraction of the viscosity of water.  There are obvious problems with
>operating such a facility (previously hashed over in this group), but I
am
>not convinced that there are any show stoppers.
>       Yesterday I spent several minutes in semi-darkness in 110 feet of
>water at 8 C, with my body tissues rapidly loading with dissolved
nitrogen as
>I breathed air from a system which inherently has a number of single
point
>failure modes.  I enjoyed it thoroughly - I was sport diving on SCUBA.
>However, although this was a routine dive I probably would have been a
lot
>safer if I was in a spacesuit submerged in 10 feet of pentane, with
safety
>personnel watching every move and standing by to haul me out at the first
>sign of trouble.
I don't know enough about the viscous properties of
pentane to know if it's a good neutral buoyancy medium,
but I can tell you it's not just a lone guy in a pressure suit in
these tests. At NASA Marshall, for example, a two-person
EVA simulation includes the following people in on scuba:
  - 4 safety divers (2 for each EVA subject)
  - 2 utility divers (1 for each subject)
  - 2 water safety divers
  - 2 swim camera operators
  - 2 still/movie photographers
  - from 0-4 support divers for the test hardware, depending
      on the test in progress.
I don't think these folks would be very happy, scuba diving
in pentane or other chemicals. (It's bad enough in pool
water, causing your hair to turn green and reach the
approximate consistency of straw after a few weeks of
constant diving...)

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

Date: 21 Mar 1993 19:27:10 GMT
From: Dave Akin <[e-mail]>
Subject: Water Simulations (Was Re: Response to various attacks on SSF)
Newsgroups: sci.space

In article <[e-mail]> Henry Spencer,
[e-mail]
writes:
>The evidence to date is that the EVA trainers *can't* accurately predict
>tricky operations like satellite repairs.  They've muffed three out of
>four, if we don't count the GRO contingency EVA.
Wait a second, how do you figure that? The Solar Max
grapple (STS 41-C) failed due to a mechanical failure, but
when the satellite was captured, the servicing procedure went
smoothly, and significantly faster than the (conservative)
timeline. The hydrazine refueling demo (STS 41-G) was
completely nominal. The Palapa/Westar rescues were
complicated by lack of configuration control on the satellites,
so the interface bars didn't fit as planned. The Leasat repair
was completely nominal, the GRO contingency only took a
few seconds of actual "hands-on" to get the boom deployed,
and the Intelsat rescue went fine as soon as the satellite was
captured.

Look, I really don't want to get into a shooting war here, but I
think the bottom line is this: we are not currently able to
accurately replicate complex 6DOF motions in the
microgravity environment in such a way as to provide full
training to EVA crew. That's a true statement as ot hins point
in time regardless of simulation media or training technique.
But we do know a helluva lot about neutral buoyancy AND
EVA, and if you think you can use EVA as a valid way of
attacking the technical viability of SSF, you're grasping at
straws...

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

Date: 21 Mar 1993 13:31:54 -0500
From: Pat <[e-mail]>
Subject: Why use AC at 20kHz for SSF Power?
Newsgroups: sci.space

In article <[e-mail]| [e-mail] (Steinn Sigurdsson) writes:
|In article <[e-mail]> [e-mail] (Pat) writes:
|
|
|   In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:
|   >In article <[e-mail]> [e-mail] (Richard A. Schumacher) writes:
|
|   >   Oh, nuts. So a 20kHz power system saves 2,000 pounds, huh?
|   >   Assume it costs $3,000 per pound to launch. Spend $6M on
|   >   the extra weight of a 400 Hz system, and 20 minutes later
|
|   >If it were to become standard and used on other systems
|
|   If the idea were so hot,  then it would be used on other areas.
|
|And by induction to all other areas we see that nothing new need
|be developed...
|

Gee Stein.  You must have graduated from the nick Szabo school of
debate.  I never said  that progress should stop,  but How come
Nobody uses it?  My local power utility is paying me to replace all
the indandescent lights in my house with floursecents, in order to
save some generated power.  They are underwriting the developement of
the E-Lamp, a 2 MHZ induced lighting coil even better then flourescents.
RFI is currently a big problem.

Space engineering should develope and fund those areas it has to, not
serve as a pet slush fund for every pet boondoggle that comes ou;of someones
ear.  Who funds Closed and semi-closed life support?  NASA, Why?  because
they need it.  IF the Air FOrce were to,  that would be a boondoggle.

Stein, you get so fascinated with someting being new,  you forget the
utility value of money and the risk reduction.  The DOE national labs
should be testing High Frequency power,  NASA should only leap on this
when MASS becomes a crisis, and fat as FRED is,  it wasn't necessary.

|   >it would save a lot more weight in the long run.
|   There were never plans to ever expand SSF beyonf the
|   EMCC Eight Man Crew COnfig,  and  that was based upon
|   very speculative budgeting.
|
|Look, NASA and others will hopefully over the next few decades
|put a lot of power consuming items into orbit and chances are
|we'll want to transmit most of the energy by electric currents.

NASA had very few plans for SSF beyond it's 25 year life.  SSF
was planned out as  a closed ended plan.  Any ideas beyond that are
in your Imagination.  Down here, METRO is a closed end plan.
93 track miles are all we will ever get, without enormous cash
infusions.  Look at reality, first, stein..

Also, most of the packages flying will be small systems.  I imagine
they will do what every other package does.  live on DC, with a 400 HZ
AC system. I think galileo does that.

|Now, maybe the current systems are optimal for this, maybe it
|would be better ab initio but with current power electronics to
|have higher frequency AC - _but_ if you think in the long run
|a new technology will be an improvement then the time to adapt it
|is when you start putting big power hungry semi-permanent structures
|into place. For space, that is now.
|

No stein.  THe time to place new systems is after you have developed
the technology and worked down the risk factors and  understood
the system implications under all circumstances.

Here is a simple case.  Composite materials are far stronger and
lighter then metals.  In fact for large structures they are often
cheaper, because they need not be Forged in giant presses or
machined on giant lathes,  yert what is the pressure vessel design
for Fred,  Aluminum?   WHY?

Because aluminum is better understood in the Vacuum environment.
Gee Stein, why aren't you bellowing for an all composite station?
Ab inito, if htey weren't doing this, why then no-one would.......
|   >When you're about to put up the first major piece
|   >of infrastructure in space, one that might in principle be
|   >expanded, it becomes sensible to consider the possibility of
|   >whether a new standard for such things as power systems makes
|   >sense in the long run.
|
Funny you mention standards.  When I suggested a metric standard,
you moaned about english being fine, and who needs stnadards anyway.

|   You mean, the way most things are built upon previous knowledge base?
|   Gee stein, you seem real positive over this technology,
|   why don't you go and build some lab equipment that pulls this
|   as prime power.
|
|The point is not the 20kHz in particular, the point is that
|_now_ is a good time to look into whether to make these kind of
|changes - I don't know if the 20kHz is worth it, and I suspect that
|the contemptuous dismissal of its potentials by you and other is
|posturing bullshit fuelled by hindsight.
|

It's not posturing bullshit, it's contemptous dismissal of an idea
that is plainly ridiculous and a absolute waste of my tax dollars.
You work at an observatory, wouldn't you have rather seen the
millions dumped into the High frequency power studies poured into
CCD developement, or into funding new orbiting instruments?

|
|This is the whole problem your way of "accounting" produces.
|What if over the next 150 years using 20kHz power were to save
|2 trillion dollars? But, we'll never know, because at any one time
|it was cheaper for that one project to stick with the old stuff.

Sorry, Stein, nobody accounts for anything with more then a
25 year lifespan.  If you need a 100 year payout, you are
looking at  technological obsolesence.

All systems have to be based upon the expected working life,
and technological obsolesence is a major factor.  look at how many
computer technologies have died, in 10 years.

And by the way, 2 trillion dollars over 150 years is petty change,
we are talking about 15 billion dollars/year, and if you place any
sort of interest rate on the money, you are talking only 3-4 billion.

Petty change in DC.  Stein,  you should study a little accounting,
it would help you out.


|You just don't get it, it's NASAs purpose to look into these
|alternatives without having to worry about whether the immediate
|benefit to that particular project provides a good return in the
|next N quarters. I'm really glad people like you weren't in charge
|of the Royal Society of London 150 years ago.
|

Gee stein, you dont get it.
Nasa doesn't look into new alternatives without worrying about
immediate return for projects.   Every program manager works
hard at risk reduction on his particular program because if the
program goes south, he's out of a job.  A major complaint I and Henry have
about NASA is they don't have an ongoing engineering research and
testing program.

It is the purpose of every project to succeed.  and gratuitous slurs
about the Royal society are un-needed.  ANd if you knew more about
history then about stars,  you'd know the brits were very big on
tying innovation to existing technologies.

|   >Yet, when they do and it doesn't work out they are chastised
|   >(often by the same people) for wasting money when they could
|   >have been using old and tried technology, and using the
|   >magic of 20-20 hindsight it becomes "obvious" that the
|   >new concept tried wouldn't work.
|
|   If they had a solid disciplined engineering developement program
|   to prove and test all this gear,Id believe it, to be worth
|   exploring, but to go out on a tremendous technological limb
|   on an untried technology on the most expensive NASA program this
|   Decade, maybe even century,  is just plain rank foolishness.
|
|No, it isn't. NASAs _purpose_ is to try out new technology,
|Maybe somebody could tell NASA just exactly how much they're allowed
|to innovate at any one time? Or are they only supposed to be
|innovative on projects that will definitely work out?
|

If they had a solid R&D program, then you integrate the technologies.
but this one was indefensible from any point,  and even they ran
away from it when it totally failed.

Tell me this, steinny.  IF weight was such an issue, why did they
end up with a pure DC power system?

|
|   No doubt, smaller then that for 20KHz.   Aren't most scientific
|   devices hand built?  if it was production gear,  you'd get it at toys R us
|
|well, if NASA had gone to 20kHz in 1963 and established a market
|then it would probably be cheaper to use that now, maybe.

And if pigs had wings, in 1954,  the first american on the moon
would have oinked.  If the only defense you have for an argument is
if it had been done before, it would be better,  then I suggest you
stop working on astronomy and start working on a TARDIS.


|And, yes, most scientific devices are handbuilt at some
|level, especially in astronomy.
|

Then if most devices are hand built,  then don't usse that as an excuse for
your petty argument.

|   and lots of stuff is production built for 400KHz.  Radars,  computers,

|   Actually my simple acid test on 20KHz, is why Boeing doesn't use it.
|
|They're probably waiting for NASA to switch to it and to provide a
|market large enough that parts manufacturers will mass produce the
|components cheaply - and have the database on in-flight safety.
>After all, that's how they get a lot of their innovation.
>

Gee stein, I hate to say this,  it must hurt your perfect little
world,  but Boeing's commercial market is probably 2 orders of magnitude
larger then NASA.  NASA spends about 1-2 billion/year on hardware,
Boeing probably sells 15 Billion / year on aircraft.

NASA buys about 10-12 rockets/ year.   Boeing sells 2-300 aircraft
per year.

Believe me,  THese guys have their own markets.  Some things they
glom off NASA and AF programs, but this one they don't need to.
And besides, stein, if 20 KHz was so hot, why aren't any other
nasa programs pursuing it?

>   If resonant inversion was such an efficient method,  and the weight
>   savings were so high on motors, etc,  then 747's would be converted
>   over to this standard,  or new boeing hardware would use this.
>
>Why, if the cost of change over in the short run is too high, then
>they'll never change over because by your accounting rules they're
>not allowed to. Maybe somebody will do us a favour and bomb the
>factories, then they can be rebuilt to produce whatever the best
>current technology is rather than what was frozen in 50 years ago.
>

Gee stein,  advocating terrorism.  Poor occupation for an astronomer.
And I don't think 5 year payoffs are unacceptable.  I guess boeing
doesn't see even a 5 year payoff.  maybe they see a 20 year payoff.
No, if they did, they'd use this in the 777.  Um.  Must mean there is a 50
year payoff.   That means this idea, may pay off around the time
I shuffle on to the next world.  Bad Accounting, stein.

>   Commercial aviation is very weight conscious.  Military are even more,
>   yet none of these guys have ever looked at this, to my knowledge,
>   and boeing is very cash rich, and the AF spent 10 years with money
>   as no object.
>
>They have the same resistance to change, the changeover is expensive
>and you lose compatibility until it is complete - it is the classic
>instance of going with low front-end costs and higher long term costs.
>

Gee.  these sorts of things are okay for all practical engineering,
but when you hit "Magical Space" then all rules of engineering
practice become ir-relevant?  No wonder you aren't an engineer.

>Now, it may be that 20kHz AC even then doesn't work out,
>but looking at it as an option just wasn't that stupid an idea,
>this is why NASA is risk shy, they spend money on something a little
>more speculative, one particular path doesn't work out and people
>like you are roasting them - give the people a fucking break.

You sound like Fred.  Blaming me for All of NASA's short comings.
Looking at it, was one thing,  but It's one thing to have a few reports,
done.  THis was a design Spec, until the brass-boards failed.
A few grand would be one thing,  no, I'd bet they spent
more in the neighborhood of 20 Million before they abandoned the idea.

ANd If AC power was such a weight savings, why didn't they go to
400 Hz AC?  I can't believe that the Loss of Resonant Inversion
would push them all the way to DC.

Look at their behavior.  THeir BoonDOggle failed, and they went all the way
to the other end.  AN ALL DC station.  Even the shuttle uses mixed
DC 28V / 400 HZ AC 120/208 I believe.

I'll give them a break when they deliver the station they promised at
the original budget.  Until then, fuck them.  I'v egot my own
boondoggles to fund.

pat

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End of Space Digest Volume 16 : Issue 349
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