Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/v08/V8_256.ZIP/V8_256

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From ota Sat Jun 18 03:06:28 1988
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Date: Sat, 18 Jun 88 03:06:14 PDT
From: Ted Anderson <ota>
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Subject: SPACE Digest V8 #256

SPACE Digest                                      Volume 8 : Issue 256

Today's Topics:
              Re: women in space
            Re: Naming the space station.
           The launch loop author replies:
             NTSL := John Stennis
            Tony England resigns from NASA
              Re: Space Agencies
               Re: Space Station Names
----------------------------------------------------------------------

Date: 26 May 88 14:11:24 GMT
From: mmm![e-mail]  (Kurt Allen)
Subject: Re: women in space

In article <[e-mail]>, [e-mail] ("Carlos A. lopez") writes:
>    I remember hearing on one of those half hour "Gee, isn't science neat"
> shows that women have lower metabolisms (overall) than men.  Some comments
> were also made that the first interplanetary crews might be mostly women
> to reduce the demands on the life support system.

Just a note. Women scuba divers typically use approx. 2/3'rds of the
air that male scuba divers, of the same abilities, use. My women diver friends
will last almost as long on a 40 cu foot air tank as myself on a 72.
--
-----------------------------------------------------------------------------
rutgers!umn-cs!mmm!allen    |    Kurt W. Allen
ihnp4!mmm!allen            |    3M/Digital Imaging Acquisition Center
-----------------------------------------------------------------------------

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

Date: 26 May 88 15:26:53 GMT
From: [e-mail]  (Robert Eachus)
Subject: Re: Naming the space station.


     I like the idea of naming something after Robert Heinlein, but it
shouldn't be a space station in low earth orbit.  A lunar colony would
be much more appropriate.  Willy Ley is  already on the  moon, but his
name would  be very appropriate for  a station on or  around  Mars.  I
hope George Low's name can get on to the list considered for the Space
Station, to me it seems the most appropriate,  and it  would  be used!
"I'm going to Low  Station next week...",  does not  sound pretentious
and delivers the  message, where "I'm  going  to Minerva next week..."
just doesn't hack it.


                    Robert I. Eachus

with STANDARD_DISCLAIMER;
use  STANDARD_DISCLAIMER;
function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is...

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

Date: 26 May 88 03:13:28 GMT
From: tektronix!tekcae!vice![e-mail]  (Keith Lofstrom)
Subject: The launch loop author replies:


As John Gregor (a former student of mine and an unabashed partisan for
the launch loop) observes, it is hard to make a valid criticism of the launch
loop without reading the technical paper.  The December 1983 "Analog" article
wasn't the proper forum for technical details;  it also was written 5 years
ago and many problems have been solved since then.  However, John has done an
able job of answering most of the questions (BRAVO, John), saving me some
effort.  I will touch again on a few points and add a few of my own:

Important ideas since the Analog article:

1)  The loop should be built over mid-ocean, far away from land.  This actually
eases construction (the biggest ocean wave is flatter than most hills, for
example, and things are surprisingly quiet 20 meters down) but the most
important aspects are safety and security.  If the loop fails and throws
pieces, they are unlikely to come down on people.

2)  Loop technology is useful for other things, and this provides a growth
path for the technology.  Underground power storage and transmission may be
possible (this depends on real world small-bore rock tunneling costs, an
unknown).  "Simple" towers built around 2Km/sec ribbons can poke above
the atmosphere, and are useful for scientific observations and the modification
of intercontinental ballistic "gift packages".  Why that instead of passive
structures?  Well, without active control of guy wires and such, the passive
towers must be quite massive to survive atmospheric perturbations
(The atmosphere scales the launch loop cross section, too;  a lunar launch
loop can be millimeters across and launch kilogram payloads).  So, with your
active guy wires you might as well buy the whole package, and get the better
strength-to-weight of the loop, and get energy storage for your "gift"
modification apparatus.

3)  "But what if it fails?  Isn't there a lot of electronics to keep running?"
--- the control sections are about 1 meter long in the middle of the loop.
If they are designed properly, they will fail or not fail independently of
each other.  It takes about a 20 percent global failure rate, or 50
control sections in a row, to cause the loop to go unstable.  (Why so many
small segments?  Resolution.  What percentage good pixels are required for a
readable terminal screen, assuming a slow hollywood scroll?)    The controllers
and magnets, and even ribbon sections, may be repaired and replaced during
operation.   The launch loop has lots of small, identical pieces;  don't
think of it as intricate, think of it as highly redundant.

What is most likely to bring the machine down is incorrect programming.  With
proper instrumentation, and post-mortem analysis, such problems will eventually
go away.  In the interim, you just pick up the pieces, make some new ones, and
start the system up again.  This is part of the designed-in system cost.  Down
time with a "hot spare" would be about 2 weeks.  Down time from on-shore
warehouses a few months.  No two year waits while your engineers try to
fix boosters designed like fragmentation grenades (to please pork-barrel
senators from Utah).  You should eventually have a whole bunch of launch
loops, anyway; there's room near the equator for thousands of them.  Unlike
Paul Birch's orbital rings, many loops can coexist without tangling if one
fails.

4)  The cost can be controlled if you use the following rules:
  (a) Don't make any pieces you can't buy
  (b) Make the pieces small
  (c) Make the pieces identical
  (d) Don't stop making the pieces.
The launch loop has a few big pieces (the stations, the end magnet platforms,
and the motor platform), but those can be build by any big steel construction
company.  The rest of the stuff is small and distributed, or off-the-shelf
(like barges with gas-turbine power plants on them, cable ships, or the
factory where you make new pieces).  I still expect the loop to be damned
expensive; perhaps as much as a replacement Shuttle, meaning it will be a
while before it's worthwhile to do.

5)  Stabilization:  A big problem has been the stabilization of the
infamous equation 33:
.EQ (33)
{ { a sub rs ~ + ~ a sub 0        }    over
  { a sub s  ~ + ~ mu omega sup 2 } } ~ = ~
{ ( omega - omega sub k ) sup 2   }    over
{ mu omega sup 2 ~ + ~ ( omega - omega sub k ) sup 2 }
.EN
The  $$ a sub 0 $$ term is the natural instability of a magnetic levitation
system, while the $$ a sub rs $$ term is the controller output as a result
of measuring the ribbon-track spacing.  The $$ a sub s $$ term is based on
the absolute position of the track, and must be determined (much more
expensively) with laser interferometers and other such arcana.  The trick is
to come up with control equations that yield a finite number of damped poles
over a wide range of $$ omega sub k $$ (which is the wavenumber times the
velocity for a perturbation, == $$ 2 pi V sub r over lambda $$).   I spent over
a year stupidly banging away on $$ a sub rs $$ only, until I realized it was
impossible to stabilize without ground measurements of some sort.  After
that, another year banging away on user-fiendish symbolic math packages
trying various likely permutations of both control equations.  Finally it
dawned on me that you should add a term to the left side proportional to
the right, and to the right side proportional to the left, throw in a few
appropriately scaled damping factors, and everything stays hunky-dory and
fourth order.  This is where things are at right now;  I am still figuring
out what the physical implications of all this are.  I've got a new version
of the paper with the equations in it;  I'll be bringing copies to the
Denver conference.

6)  "Okay, smarty pants, if it's so simple, why aren't you building one?"
Well, first, I'm lazy.  I wrote the "Analog" article to drum up interest.
I mailed out around 200 copies of the paper, and wrote hundreds of personal
letters.  I was hoping someone would steal the ball and run with it. Nuh-uh.

7)  "Where's my copy of the paper?"  Well, see the part about lazy.  Keep
bugging me, third try should do.  If you live in Tierra Del Fuego, find out
what the U.S. postage for 5 ounces is to you, so I won't have to call the
always-busy line at the post office (would someone send me a list of current
international mail rates?  Thank You!).  Postage is cheap, time is precious.

8)  "Why do this?"  Well, I want to live and work in space.  I don't want to
make somebody else pay for it, so it must be affordable.  Since nobody else
is working on $10/lb low-gee launch systems, I guess it's my job.  Sure the
thing is too damn big.  So are the alternatives, and they yield a much smaller
payback for the same investment.  If somebody out there has a system that will
accomplish the same ends with a smaller investment, PLEASE LET ME KNOW!  I'll
send them money.  I'll build their electronics.  I'll clean their toilets if
they need it!

I may not get into space by working on the launch loop, or even helping on
some yet-to-be-defined better system.  But I sure as hell WON'T get there
by telling somebody else how hard it is.  If there were easy solutions, we'd
already be there!


Forty years from now, when you're in the back of the ambulance racing to the
hospital, while the EMT is trying to restart your heart, you may have other
regrets, but mine will probably be "I didn't make it into space".  Most of
the current crop of space "activists" will be dead before it's affordable to
go there.  Whose fault is that?


--
Keith Lofstrom   ...!tektronix!vice!keithl   [e-mail]
MS 59-316, Tektronix, PO 500, Beaverton OR 97077  (503)-627-4052

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

Date: 26 May 88 07:38:09 GMT
From: sonia![e-mail]  (Eric Behr)
Subject: NTSL := John Stennis

===========================================================================

PRESIDENT RENAMES NASA CENTER FOR SEN. JOHN C. STENNIS

May 20, 1988

RELEASE 88-36


     NASA's National Space Technology Laboratories (NSTL) was
officially renamed the John C. Stennis Space Center by Executive
Order of the President today.

     President Reagan signed the executive order to rename the
NASA center for the distinguished Mississippi senator who is
retiring after 41 years of service to the nation and the state.

     The president's executive order said, "Sen. John C. Stennis
has served his country as a United States senator for over 40
years and has steadfastly supported the nation's space program
since its inception.  He has demonstrated visionary leadership
and has consistently worked to assure United States world
leadership and preeminence in space.

     NASA Administrator James C. Fletcher said "John C. Stennis
has served as the father of NSTL since he led the efforts for
its creation.  His leadership of the nation's space program stands
as a monument to his career of significant accomplishments."

     At NSTL, director Jerry Hlass said, "Senator Stennis made
major contributions to our country and our state throughout his
long and distinguished career.  His support to the national space
program has been consistently strong since NASA's inception.  His
close association with our center has contributed significantly to
the growth and progress we have experienced over the past 27 years.
He has been a leader and strong advocate for a preeminent role in
space for the United States.  The senator's interest in the
advancement of science and technology continues today with his
support of the Space Station, our nation's next logical step into
space."

     The space center is one of eight NASA field centers in the
country.  NASA selected its Hancock County location in 1961 to test
the Saturn V first and second stages for the Apollo program.  The
site was designated the Mississippi Test Facility when Saturn rocket
testing began.  In 1974 the installation was named the National Space
Technology Laboratories because of its achievements and unique
capabilities in space applications and Earth resources technologies.

     During the period between the Apollo and Space Shuttle
programs, Stennis was instrumental in helping NASA achieve full
utilization of the installation's facilities.  Today, the NASA
center employs more than 5,400 people and is the home of 18 federal
and state agencies engaged in environmental, oceanographic and
defense-related activities.

     Stennis, a frequent visitor to the space center that now bears
his name, continues to support the space agency's current and future
efforts.  In his December 1987 "Report to Mississippians" newspaper
column, the senator wrote, "While it is essential that we prioritize
our spending and bring our federal deficit under control, we must
look ahead to the future of our country."

     "The next logical step in space exploration is the establishment
of a permanent Space Station that will assure world leadership in
space for our country in the 1990s and beyond.  We must be committed
to this important program that will enhance our capabilities for
scientific learning while stimulating our nation's economic
development and defense programs."

===========================================================================
                                                       Eric

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

Date: 26 May 88 08:17:59 GMT
From: thumper![e-mail]  (Phil R. Karn)
Subject: Tony England resigns from NASA

Another astronaut has resigned from NASA because of delays in the
Shuttle and Space Station programs: Dr. Tony England. He flew once, on a
1985 Challenger Spacelab mission during which he ran an amateur radio
operation in his spare time.  Tony's recent project in NASA had been
the Space Station.

See the AMSAT bulletin on rec.ham-radio for further details.

Phil

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

Date: 26 May 88 18:14:07 GMT
From: trwrb!ucla-an!ondine![e-mail]  (Steve Jenkins)
Subject: Re: Space Agencies

In article <[e-mail]> [e-mail] (SPACE EXPLORATION) writes:
>
>
>    Hello everyone.   We need the addresses for ESA and the Soviet
>                      space program.

    European Space Agency
    8-10, rue Mario-Nikis
    75738 Paris Cedex 15
    FRANCE
    (33.1) 42.73.76.54

--
Steve Jenkins            ucla-an![e-mail]
Research Engineer        {decvax,ihnp4}!hermix!ucla-an!steve
UCLA Crump Inst for Med Engr    (213)-825-4364
Steve Jenkins            ucla-an![e-mail]
Research Engineer        {decvax,ihnp4}!hermix!ucla-an!steve
UCLA Crump Inst for Med Engr    (213)-825-4364

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

Date: 26 May 88 20:30:35 GMT
From: uflorida!novavax!proxftl![e-mail]  (Rafael Mayer)
Subject: Re: Space Station Names

In article <[e-mail]>, [e-mail] (Adrian Hurt) writes:
> I thought Minerva was the Roman name for the Greek goddess Athene, the goddess
> of wisdom.
>
> Maybe the Romans, being more militaristic, put her in charge of both, but I
> thought that war was the speciality of Mars (Ares in Greek).

Your right. She was also a warrior though. Her shield, the Aegis, is famous
in the Greek Mythos.  According to Homer, in the Iliad, she was one of the
gods egging on the Greeks and Trojans against each other.  (Oh, embarrasment,
I forget on what side whe was on.)

How about calling it Aegis?  I like the concept of the shield, and the wise
warrior and all that.  JMHO.

Rafael                  allegra!novavax!proxftl!rafael

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

End of SPACE Digest V8 #256
*******************