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Subject: SPACE Digest V13 #762

SPACE Digest                                     Volume 13 : Issue 762

Today's Topics:
              Re: A Space Science letter
             Re: Pioneer Venus ?
             When Is Next Shuttle Launch?
             Re: Access to Space
             Manned Space Flight
             Re: Access to Space
             Re: Access to Space
              Re: anti-gravity?
             Re: Slingshot effect
              Re: Body Mass Measurements
               Re: Mars "face"
              Re: Fred's Operatic Death

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: 18 Jun 91 00:11:07 GMT
From: sequent!muncher.sequent.com![e-mail]
Subject: Re: A Space Science letter

In article <[e-mail]> [e-mail] (Dani Eder) writes:

>If the committees are too dumb to understand this, we need to educate
>them fast, since projects winding down, like Mars Observer, will get
>unneeded windfalls, while those ramping up will be stalled.

Congress has to cover a wide range of topics including DoD, DOE,
Commerce, Agriculture, EPA, etc. etc.  It cannot be expected to understand
details of planetary missions, any more than a rocket engineer can be
expected to be well-versed in tort law.  It is up to the NASA leadership to
provide an intelligent budget and guidance on these issues.  They have
failed to do so.

On this topic, is there any way for space explorers to transfer
money "under the covers" to provide the funds where they are needed?
For example, CRAF work performed under the MO budget line, etc.


--
Nick Szabo            [e-mail]
Embrace Change...  Keep the Values...  Hold Dear the Laughter...
These views are my own, and do not represent any organization.

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

Date: 18 Jun 91 03:24:20 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!think.com!snorkelwacker.mit.edu!bloom-picayune.mit.edu![e-mail]  (Peter G. Ford)
Subject: Re: Pioneer Venus ?

In article <[e-mail]> white@nereid (H. Peter White) writes:
>I've heard rumors lately that Pioneer Venus will be sent into the atmosphere to
>collect data for future Magellan work. I guess this would mean that Pioneer
>Venus will collect data till the very end.
>Anyone else heard anything about this, or did I hear wrong?

You've got it half right--the Pioneer Venus spacecraft will indeed be
captured by the Venus atmosphere, and burn up, sometime next fall, but
it won't be deliberate... the spacecraft ran out of fuel long, long
ago, (1980, I think) and its orbit has been wandering ever since.

Its last few months will be closely monitored by Magellan engineers
(among others), in order to plan for an aero-breaking manoeuver in
which the Magellan spacecraft (which *does* have plenty of reserve
fuel), will dip into the fringes of the Venus atmosphere in order to
turn its current elliptical orbit into a more nearly circular one,
which is desired in order (a) to obtain high quality measurements of
the Venus gravity field, and (b) to increase radar resolution in polar
regions.

Peter Ford
MIT and Magellan Project
(also Pioneer Venus, a long time ago).

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

Date: 18 Jun 91 19:03:01 GMT
From: ns-mx!ccad.uiowa.edu![e-mail]  (Peter Koch)
Subject: When Is Next Shuttle Launch?

When is the next scheduled space shuttle launch?

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

Date: 18 Jun 91 18:29:34 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!think.com!yale.edu!ox.com!hela![e-mail]  (Allen W. Sherzer)
Subject: Re: Access to Space

In article <[e-mail]> [e-mail] writes:

>>Communications satellites are a pretty loose defintion of 'industry'...

>Interesting.  This ("loosely" defined :-) self-sustaining industry is $6
>billion per year.                         ^^^^^^^^^^^^^^^

It is a big industry but it is by no means self-sustaining. Buyers of
launch services only pay the incrimental cost of their launches. They
use huge amounts of infrastructure provided by nasty central planners
(some of it constructed to support evil manned space). This is true for
every launch proveder in the world today.

If we did it your way there wouldn't be any launchers at all.

  Allen

--
+---------------------------------------------------------------------------+
|Allen W. Sherzer |   DETROIT: Where the weak are killed and eaten.         |
|   [e-mail]   |                                                         |
+---------------------------------------------------------------------------+

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

Date: 18 Jun 91 19:06:41 GMT
From: agate!bandit![e-mail]  (Wayne Lee)
Subject: Manned Space Flight

Seeing as how I cannot seem to access Mr. Nick Szabo's network
through the mail, I am posting this.

I think I and a lot of others out there would be especially
interested in EXACTLY what aspects (if any) of manned space
flight including the shuttle does he support as "useful".


                    Wayne Lee

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

Date: 18 Jun 91 21:03:50 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!caen!ox.com!hela![e-mail]  (Allen W. Sherzer)
Subject: Re: Access to Space

In article <[e-mail]> [e-mail] writes:

>Oh boy, now we're down to "good vs. evil".

I'm just using your own words Nick. If you don't like them then
don't use them. As to the rest of it, I am just pointing out that
if the standards you apply to projects you don't like where applied
to projects you do like, then they wouldn't have them either.

Communication satellites are NOT self sustaining because they only
pay incrimental launch costs. This is true for both the US and all
world providers.

  Allen
--
+---------------------------------------------------------------------------+
|Allen W. Sherzer |   DETROIT: Where the weak are killed and eaten.         |
|   [e-mail]   |                                                         |
+---------------------------------------------------------------------------+

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

Date: 18 Jun 91 21:55:11 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!rphroy!caen!spool.mu.edu!uwm.edu!ogicse!sequent!muncher.sequent.com![e-mail]
Subject: Re: Access to Space

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:

>Communications satellites are a service.  The service sector of the
>economy does not create signifigant real wealth,

If the ability to communicate instantly across the planet does not
constitute "wealth", what does?   My particular business, Sequent,
would lose over half of its revenues if we couldn't talk and send
faxes to our European offices via satellite.

Perhaps we could also say that steel mills and airplanes don't
create real wealth, because that's merely manufacturing and
transportation.  Only farms that make food are real wealth.
Ad absurdum.

I find your arguments quite astounding.  Perhaps what you are really
trying to say is that, because the industry does not employ astronauts,
you don't care about it?



--
Nick Szabo            [e-mail]
Embrace Change...  Keep the Values...  Hold Dear the Laughter...
These views are my own, and do not represent any organization.

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

Date: 18 Jun 91 20:24:42 GMT
From: Teknowledge.COM!unix!fritz.sri.com![e-mail]  (John Stach x6191)
Subject: Re: anti-gravity?

In article <[e-mail]> [e-mail] (Brett Kottmann) writes:
>
>    A researcher in Scotland has developed a device that harnesses
>gyroscopic energy to lift a device against gravity--antigravity for all intents
>and purposes.
>
> [... details deleted]
>
>    Interesting, but is it feasible?  He claims that using nuclear
>generators, it can be used to power spacecraft at a _constant_ 1G.
>
>Brett

No, it works on the same ordinary principles that the one on Beyond
2000 works on.  I will elaborate along with a simple (seemingly
innocuous) modification that will eliminate the effect tomorrow (if
someone else doesn't).

HINT: The principle cannot be used for spacecraft although it can and
has been used for aircraft.


John
I'm not antigravity, just proflight!

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

Date: 17 Jun 91 16:17:30 GMT
From: [e-mail]  (Scott A Geels)
Subject: Re: Slingshot effect

In article <[e-mail]> [e-mail] (Matthew T Velazquez) writes:
>In <[e-mail]> [e-mail]
>(Les Carleton) writes:
>
>>Can you please explain the "slingshot" effect as used on recent
>>probes. I understand that it increases the velocity of the vehicle by
>>making passes around the sun. I'm not a physics or Astrophysics major
>>so it may seem a naiive question. What I don't understand is why the
>>velocity increases.  Surely if a pass of the sun is made, the energy
>>conservation law will come into play and the vehicle will end up with
>>the same velocity at its original distance from the sun as it had when
>>left there (after launch?).
>
pseudo-proof: (pardon the ascii attempts at notation)

V'(0,1) = velocity of spacecraft wrt the center of mass (CM),
          initial (0) and final (1)

V (0,1) = velocity os spacecraft wrt the Earth (or Sun, or Solar
          System), initial (0) and final (1)

V (CM)  = velocity of center of mass (Venus)

Definition of CM:  (this is elementary physics)

V(0) = V'(0) + V(CM)
V(1) = V'(1) + V(CM)

We want |V(0)| < |V(1)| , so that we gain energy

Ergo, we want:
|V'(0) + V(CM)| < |V'(1) + V(CM)|

Example of how this can be the case:
V'(0) = -5i(hat)
V'(1) = +5i(hat)
     (note: these must have the same magnitude, by conservation
            of energy)
V(CM) = +i(hat)

|V(0)| = 4
|V(1)| = 6

Disclaimer: the numbers used here are bogus

Therefore, net gain in velocity wrt the Earth!

You can also use this to lose velocity.


        Scott Geels

[e-mail]
[e-mail]

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

Date: 17 Jun 91 15:46:01 GMT
From: mintaka!think.com!zaphod.mps.ohio-state.edu!swrinde!ctcvax.ccf.swri.edu!rocke![e-mail]  (Bob Robison)
Subject: Re: Body Mass Measurements

In article <[e-mail]> [e-mail] (Alan Herbst) writes:
>>How are body mass measurements made aboard the shuttle in the weight-
>>lessness of space?  Is it the mirco-gravity at 180 miles up?
>>
>A good answer was received from:
>
>-- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office
>   <[e-mail]>

>"There are various devices used, including spring-based mechanisms which
>"bounce" the crew member off a spring and calculate body mass through
>f=ma, a "shaker" mechanism which moved crew members around and
>calculated their mass by measuring inertia, and several others.  I once
>took a class from Dr. Thornton, a former astronaut (STS-51C) and
>researcher of human physiology in space.  Fascinating stuff.  The main
>problem with all zero-G mass measurement systems for humans has been
>that people are flexible and mostly fluid.  When measuring a flexible,
>fluid-filled body by bouncing or shaking, that body tends to wiggle and
>slosh, which throws off the mass measurements."
>

Sorry I'm lating responding to this -- I was out last week and am just
now reading my news...   Southwest Research Institute designed and
built the Body Mass Measurement Device (BMMD) and the Small Mass
Measuring Instrument (SMMI) that were aboard the Columbia on this past
mission.  Both of these devices work by supporting the mass to be
measured on stiff springs.  The mass is then deflected to one side and
released which causes the mass to oscillate as the springs deflect one
way and then the other (This is a side to side type of motion).  The
period of oscillation is measured very accurately and the mass is
calculated from that period.

As mentioned in the above post, the "sloshing" of one's internal
organs is one of the problems with getting accurate measurements.
On the BMMD, the subject sits in the device in a sort of "cannonball"
position with knees pulled up close to the chest and is asked to
tighten his/her muscles during the measurement.  This minimizes the
"sloshing" and provides better mass measurements.  One thing I found
interesting when we were researching how the Soviets did this, is that
their version of the BMMD looked like a column with a plunger in it
that moved up and down.  The subject bent over the column with the
(presumably) padded plunger pressed up against the subjects abdomen.
The plunger then oscillated up and down -- doesn't sound like a fun
way to be 'weighed' to me.

BTW, the SMMI is used to measure masses in the range of about 1 gram
to 1 kilogram, and is used for measuring chemicals, rodents, etc.  The
earlier version of the SMMI was called the SMMD.  Both the SMMD and
the BMMD were aboard SKYLAB.  The SMMD required a connection to a TI
calculator that ran the mass calculation.  The SMMI is more automated
and uses a built in computer to do the calculation and drive a
dedicated display.  This was the first flight for the SMMI, which I
first worked on in 1979.  Yes, it uses a state-of-the-art 6502
processor!

Well, didn't mean to carry on so much -- but that is the background.
And Dr. Thornton worked very closely with SwRI on the development of
these mass measurement techniques.  I believe work began on that in
the late 60's.

bob
--
Bob Robison    - Southwest Research Institute, Electromagnetics Div.
[e-mail]
{sun!texsun, gatech!petro, uunet!cs.utexas.edu}!swrinde!dfsun1!robison

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

Date: 17 Jun 91 23:06:37 GMT
From: tristan![e-mail]  (Loren Petrich)
Subject: Re: Mars "face"


    I've seen a copy of the Mars Face that was made available as a
GIF. It looks remarkably like the face of a macaque monkey.

    I guess I'm not too impressed by it.


$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Loren Petrich, the Master Blaster: [e-mail]

Since this nodename is not widely known, you may have to try:

[e-mail]

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

Date: 17 Jun 91 22:02:33 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jpl-devvax![e-mail]  (Douglas Creel)
Subject: Re: Fred's Operatic Death

>
>The fact that your employer, JSC, gets its revenues via the IRS
>for astronaut projects makes me discount your "pro-manned"
>statements.  Quit wasting my tax money making self-serving posts to the
>net.  Quit wasting my money on engineer-welfare projects like Fred.  Get a
>real job.
>
>
>--
>Nick Szabo            [e-mail]

You sound like a desperately lonely person, Nick. I suggest you seek some
professional counseling for this hostility problem of yours. As far as someone's
postings being a waste of your tax paying dollars, well, Nick, you're not the
only one who pays taxes on this net.
Maybe we should clarify exactly what it is you consider an "engineer-welfare"
project. What about me? I work for the Mars Observer project which is decidedly unmanned and would seem to fall under the auspices of one of your pet projects.
Is this welfare for engineers and space scientists? I can't recall of ever
hearing of welfare recipients who work for their living. What about all the
scientists who work for NASA, or NOAA, or the NSF, or NIMH, or any one of the
national labs. Are we all just a bunch of self-serving welfare recipients,
be that self-serving "astronaut-groupies" or self-serving "science-weenies"?
Please enlighten me Nick, so that this veil of ignorance which seems to
surround all of us who consider the men and women who died on Challenger heroes
and not misguided martyrs can be lifted.

Douglas D. Creel
Mars Observer Navigation Team
Jet Propulsion Laboratory

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End of SPACE Digest V13 #762
*******************