Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V13_5/V13_500.ZIP/V13_500

Internet Message Format | 1991-06-28 | 16KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/Uc9YKT:00WBw02FE5n>;
          Tue,  7 May 91 02:13:51 -0400 (EDT)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Tue,  7 May 91 02:13:46 -0400 (EDT)
Subject: SPACE Digest V13 #500

SPACE Digest                                     Volume 13 : Issue 500

Today's Topics:
             Learning from Japan
          Re: Space research, teflon, etc, etc,....
                 Mars
               Re: Hypersonic Transport
    REQUEST for information: Flight times to outer planets
          NASA Prediction Bulletins:  Space Shuttle
               Re: Hypersonic Transport
              Re: Galileo's main antenna
              EXPLOSION over Los Angeles

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription requests,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 27 Apr 91 06:41:23 GMT
From: unisoft!fai!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Learning from Japan

In article <[e-mail]> [e-mail] (Fraering Philip) writes:

[An excellent article on U.S. competitiveness]

Well said.  I would only add that if we are going to mimic the
Japanese, we should learn from them the way they learned from the
Western world after the Meiji Restoration.  The Japanese sent out
observers to the most advanced parts of the most advanced Western
countries, making lists ranking political, educational, and
technological structures in order from best to worst.  Fit with
Japanese culture was also considered.  Everything below "ichiban" --
the number one ranking -- was discarded, and the best examples of
each component of modern civilization in all of the West were implemented
over the remains of feudal Japan.

Now that Japan is equal with us -- better in some areas, worse in
others -- we need a similar process to learn from Japan -- that is,
go over and pick out the _best_ of what they do, that also fits our
own culture.  Honda, not Mitsubishi; Japanese work ethic, not
Japanese group-think ethic; just-in-time manufacturing, not
university-level scientific research; technical education, not language
education.

In the space arena, the Japanese have things to teach us in
several areas -- minitiarization, automation, efficiency,
and the scaling of technology to the market.  They also have an
extensive project in comet and asteroid research, including sky
surveys and manned asteroid sample return missions to Antartica.
On the other hand, the country as a whole is way behind in the overall
skill level, attention, and funding levels devoted to space.  This gives
us a big advantage.  Let's combine their best with our best to produce a
winner.


--
Nick Szabo                [e-mail]
"Living below your means allows you to live better than living above your
means." -- Dave Boyd    The above opinions are my own and not related to
those of any organization I may be affiliated with.

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

Date: 24 Apr 91 19:58:17 GMT
From: unisoft!fai!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: Space research, teflon, etc, etc,....

[two excellent articles on innovation, got attributions mixed up sorry]

>>...Thomas
>>Edison, Henry Ford, and the Wright brothers suffered alone for
>>many years trying to perfect their inventions.

There may be some cobwebs of myth here.  Good ol' Tom Edison, while
creating the mystique of the individual inventor, actually headed a
lab full of engineers out of which came some of the first records,
moving pictures, etc.  Henry Ford also had a reasonably well staffed
and funded operation.  The Wright Bros. were a small (two people plus
part time help) and experienced team, similar to the garage-level
airplane experimentalists of today.  Note that the Wright Bros. invented
the first wind tunnel before inventing the first airplane.  With the wind
tunnel they found several big flaws in Lilienthal's aerodynamics tables.
Solving these was a big part of getting the first Wright Flyer in the air.

Some of the garage techniques made their way into the OSC/Hercules
Pegasus project -- especially the design of the new wing -- one of the
reasons the R&D costs for Pegasus were so incredibly low by government
contractor standards.  The techniques of today's experimental airplane
enthusiasts hold real promise for bringing down the cost of aerospace
R&D.


>>Maybe we should
>>be finding modern day inventors like these and start funding their
>>research.

Hard to find them, even more difficult to fund them without giving in
to the temptation to dictate design.  The Army/Huntsville and
Army/JPL relationship of the 50's, which led to the first U.S. satellite
Explorer I and the discovery of the Van Allen belts, and the DARPA/private
industry relationships of today, strike me as good models of how government
can fund innovation without thumb-fingered interference and mis-scaling
of technology.  Government-dictated projects like the Shuttle, the fission
and fusion power programs, Space Station Freedom, etc. stand as testimonials
of how government can spend $tens of billions of dollars on good technology
and still end up having little or no positive impact on our economy --
negative impact when you realize citizens and industry were taxed for these
projects out of funds that could have otherwise gone to private R&D.



>>Space research doesn't necessarily have to be done by
>>NASA.

It _isn't_ necessarily being done by NASA.  Most of the innovations
in space technology over the last decade have come from outside
NASA.


>any government funding will make
>it just as inefficient as the current system. Control always follows
>the money.

This has not always been the case: see the Army and DARPA examples cited
above.  I believe it is possible for government to fund innovation
wisely.  But we really have to look at what works and what doesn't, and
have the political will to throw the things that don't work.


>Backyard
>tinkerers are unlikely to deliver the complex transportation systems
>we all want.

Pegasus is a shining counterexample.  It is exactly the techniques
of "backyard tinkerers" like Bert Rhutan and the Wright Bros. we need
to revitalize our aerospace R&D.


>Like it or not, we are stuck with the government doing
>a job that's too big for anyone else.

This, in a nutshell, is the myth I am fighting -- that space
technology has to be big, therefore it has to be done by big
organizations.  As long as we believe this fallacy, space technology is
going to be expensive and a long time in coming.



--
Nick Szabo                [e-mail]
"Living below your means allows you to live better than living above your
means." -- Dave Boyd    The above opinions are my own and not related to
those of any organization I may be affiliated with.

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

Date: 2 May 91 21:28:08 GMT
From: [e-mail]  (Adam R. Brody)
Subject: Mars

Can someone briefly describe the differences between conjunction
and opposition class missions in terms of relevant geometry
and duration?

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

Date: 3 May 91 04:05:13 GMT
From: agate!typhoon.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: Hypersonic Transport

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>Pretty much so.  Both the airlines and the aircraft manufacturers have
>concluded that hypersonic speeds do not appear to be worthwhile at present.
They studies you are refering to were by aircraft manufacturers and assumed
thay there would be no changes, by airlines, in the way they operate
aircraft. That is, the studies showed that a hypersonic aircraft, when
flown like a wide-body subsonic, could not make a profit. This assumption
included such things as maintnance based on distane traveled, rather than
flight time, passenger-class price tickets ( while a 2-hour flight from
LA to Tokyo could charge twice the current first-class price and fill its
seats), flying aircraft back and forth between cities (e.g. New York to
Paris to New York to Paris to...) which will result in down time from
late night closure of airports (where as this problem does not exist
for a New York to Paris to Tel Aviv to Calcuta to Singapore to Tokyo to
LA to New York type flight.)

I think, if operated in a new way hypersonics would work. (after all the
current operational patterns are optimized for subsonics. It makes sense
that they are not the best thing for hypersonics.)

                      Frank Crary
                      UC Berkeley

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

Date: 3 May 91 16:37:14 GMT
From: typhoon.ucar.edu![e-mail]  (Mark Bradford)
Subject: REQUEST for information: Flight times to outer planets


One of my roommates would like to know how long it would take to get a
Voyager-class probe to Neptune, using

a) Shuttle / IUS
b) Shuttle / PAM
c) Titan-Centaur
d) Titan IV

Gravity assists allowed.

If anybody just happens to have some estimates lying around, or if you know
off-hand, the information would be greatly appreciated!  (Don't go out of
your way.)  Many thanks!

(PS: I'd be curious as to how a Saturn V would compare, too.)

-- Mark Bradford ([e-mail]) <> To err is human, to moo bovine.
               "I'm not a squid, but I play one on the net."

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

Date: 3 May 91 21:59:37 GMT
From: udecc.engr.udayton.edu!blackbird.afit.af.mil![e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletins:  Space Shuttle


The most current orbital elements from the NASA Prediction Bulletins are
carried on the Celestial BBS, [phone], and are updated several times
weekly.  Documentation and tracking software are also available on this
system.  As a service to the satellite user community, the most current
elements for the current shuttle mission are provided below.  The Celestial
BBS may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data
bits, 1 stop bit, no parity.

STS 39
1 21242U 91 31  A 91123.10640046  .00236800  34986-4  25599-3 0   146
2 21242  56.9932 267.5322 0011102 272.5797 239.4370 16.09400028   747
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]          Air Force Institute of Technology

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

Date: 5 May 91 12:52:12 GMT
From: eru!hagbard!sunic!mcsun!ukc!edcastle![e-mail]  (J Gillespie)
Subject: Re: Hypersonic Transport

[e-mail] (Henry Spencer) writes:

]In article <[e-mail]> [e-mail] (Frank Crary) writes:

]Largely true.  But it is important to remember that *changes cost money*.
]Unless hypersonics are cheap enough to capture a large fraction of the
]total traffic -- which appears unlikely -- they are not going to be
]lucrative enough to justify it.

Agreed

]]... passenger-class price tickets ( while a 2-hour flight from
]]LA to Tokyo could charge twice the current first-class price and fill its
]]seats)...

]Not if there were fifty departures a day, they couldn't.

Agreed

]                              The first-class
]market simply isn't big enough to finance a large new airliner, especially
]an unusually high-tech one that could be expected to have high development,
]production, and operating costs.

Someone has to say it: what about Concorde?  I'm no expert on its
history, but as I understand it most of the development costs were
written off, and the service is only just profitable in spite of the
*rather* high fares (what is it now - $1000 one way? $1500?).  As far
as I can see the main function of Concorde is that of a high profile
corporate mascot.

Having said all that, yes I can see that hypersonic/ballistic
airliners would be in a different league altogether: the Concorde
project at least got some sort of a start from military supersonic
research, but as far as I know there is no hypersonic aircraft (*not*
counting spacecraft, launch vehicles, the shuttle, etc.) in production
anywhere in the world today, no suitable engine technology in
production, and zillions of other good reasons why such a project
would be economically infeasible.

]And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
]"beans are more important".             |  [e-mail]  utzoo!henry
--
  James Gillespie,     /~~~~~~~~\   Every American citizen has a chance of
 Edinburgh University /   @  @   \  becoming president.  But that's just a
   [e-mail]    /     <      \ risk they have to take.
____________________/  \________/  \__________________________________________

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

Date: 3 May 91 23:57:28 GMT
From: bu.edu!transfer!lectroid!sw.stratus.com![e-mail]  (Tarl Neustaedter)
Subject: Re: Galileo's main antenna

In article <[e-mail]>, [e-mail] (H. Peter White) writes:
[referring to Galileo's main antenna]
> >Now I would have thought that having such a large, thin metal surface always in
> >sunlight, with the other side always away from the sun, would cause it to
> >become charged, due to things like the photo-electric effect, and the fact that
> >its treavelling thru a variable solar magnetic field.

I'm not a galileo expert, but I know some of the answers you are looking for.

Given the antenna is metal (gold-plated molybdenum), any charge it accumulates
will immediatley be shared with the rest of the spacecraft. The main source
of charge would actually be collisions with charged particles (e.g., solar
wind, Jovian Van Allen belts), rather than the effect of sunlight itself.
After a while, if the charge is sufficient, the spacecraft will start
repelling like-charged particles and stop accumulating charge.

Moving through a magnetic field (jupiter's will actually be much stronger
than the sun's) may cause currents to move within the antenna, but would not
cause the object to become charged. The effect of the small eddy-type
currents thus caused should be pretty small.

As to the effect of the entire spacecraft acquiring a charge; I don't believe
it causes significant problems until coming into contact with something (and
then you get a bolt of lightning). Since this charge is spread around the
entire spacecraft, and there isn't any charge differential to worry about,
and the only effects left to worry about are the effects of accumulated
static electricity on various scientific instruments (which again, since
there are no differentials, should be fairly small).
--
         Tarl Neustaedter    [e-mail]
         Marlboro, Mass.    Stratus Computer
Disclaimer: My employer is not responsible for my opinions.

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

Date: 4 May 91 05:19:07 GMT
From: usc!mizar.usc.edu![e-mail]  (Steve Robiner)
Subject: EXPLOSION over Los Angeles

I've heard several reports on the radio this morning about a bright
'flash' of light in the sky over LA on the night of April 30th/morning
of May 1st.

Anyone know more about this?

It was described by witnesses as 'an electrical fire' and others
as 'an explosion.'  I heard one report on the radio that a witness
who happened to videotape the event had his tape confiscated by the
Air Force.

I'm not trying to spread wild rumors, just reporting what I heard on the
radio.  And from those accounts it doesn't sound like your average
meteorite.

=steve=

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

End of SPACE Digest V13 #500
*******************