Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO340.TXT

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Date: Fri, 19 Mar 93 05:48:21
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #340
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 19 Mar 93       Volume 16 : Issue 340

Today's Topics:
                          How to cool Venus
                          Luddites in space
 moon's fate when removing gravitational influence of earth (2 msgs)
                      plans, and absence thereof
                       Russians  ICBMs -> SLVs
                     SR-71 Maiden Science Flight
                  Why use AC at 20kHz for SSF Power?

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

Date: Fri, 19 Mar 1993 06:12:57 GMT
From: Michael Moroney <[e-mail]>
Subject: How to cool Venus
Newsgroups: sci.space

[e-mail] (Richard A. Schumacher) writes:

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

>Err, all that carbonate rock was created by life: corals, diatoms,
>etc., make calcium carbonate for their shells, spicules, and whatnot.

Much of it was.  Much was formed by another process, the weathering of
silicate rocks.  An example of this process is basically XSiO3 + CO2 ->
XCO3 + SiO2 (sand).  This process does not depend on life.

-Mike

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

Date: 19 Mar 93 08:40:53 GMT
From: Nick Szabo <[e-mail]>
Subject: Luddites in space
Newsgroups: sci.space,talk.politics.space

[e-mail] (fred j mccall 575-3539) writes:

>I prefer sending people to sending toasters.

Typical Luddite comment. The $billions in technology are
merely toasters, the engineers and techs who make them
merely toaster-makers, and the only people that count
are the people who have accomplished almost nothing
for the space program, the astronauts.


--
Nick Szabo                     [e-mail]

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

Date: Fri, 19 Mar 1993 06:06:45 GMT
From: Leigh Palmer <[e-mail]>
Subject: moon's fate when removing gravitational influence of earth
Newsgroups: sci.space

In article <[e-mail]> Michael Moroney,
[e-mail] writes:

>Its orbit might be more eccentric than earth, depending on where
>it was relative to earth at the time earth "vanished".

Its orbit would be more eccentric than that of the Earth regardless of
where it was when the Earth "vanished".

First, let's adopt a physically conceivable process for the disappearance
of the Earth. My idea of a good one is to have the Earth explode neatly
into northern and southern hemispheres, the two pieces recoiling with,
say, half the velocity of light. That's better than having the Earth
"vanish", and I think it retains the spirit of the question.

If the Earth explodes at full moon, the speed of the moon will be greater
than Earth's orbital speed, and the moon's subsequent orbit will be
eccentric with perihelion at the point of the explosion. If the explosion
occurs at new moon then the speed of the moon will be less than Earth's
orbital speed and the resulting eccentric orbit will have its aphelion at
the point of the explosion. The only way the moon could have an
Earth-like orbit after the explosion would be if it had Earth-orbital
velocity at the time of explosion. We've just examined the two cases for
which the direction would be correct, and neither has nearly the correct
speed. Thus the resulting orbit must be eccentric.

QED

Leigh

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

Date: Fri, 19 Mar 1993 06:51:10 GMT
From: Henry Spencer <[e-mail]>
Subject: moon's fate when removing gravitational influence of earth
Newsgroups: sci.space

In article <[e-mail]> Leigh Palmer <[e-mail]> writes:
>... The only way the moon could have an
>Earth-like orbit after the explosion would be if it had Earth-orbital
>velocity at the time of explosion. We've just examined the two cases for
>which the direction would be correct, and neither has nearly the correct
>speed. Thus the resulting orbit must be eccentric.

Note that the Earth's already is.  Not a lot, but some.  And since
the Moon's orbital velocity around the Earth is about 1 km/s, and the
Earth/Moon orbital velocity around the Sun is about 30 km/s, the
Moon's resulting orbit wouldn't be massively eccentric.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 19 Mar 93 09:07:11 GMT
From: Nick Szabo <[e-mail]>
Subject: plans, and absence thereof
Newsgroups: sci.space,alt.sci.planetary

[e-mail] (Pat) writes:

>JPL  A) Has their plate pretty full doing existing missions.

Quite the opposite, they are laying people off and rapidly
revamping their strategies in search of new missions.  It's
a time of flux at JPL, a time for it to incorporate new
strategies and visions to take advantage of the new technology
and knowledge we have going into the 21st century.

>     B) is oriented to certain mission types, and prospecting
>    is a little out of their balliwick..

JPL, Caltech, and universties that work closely with it such
as U. of Arizona, are chuck full of planetary scientist/geologists.
There are dozens of quite talented planetary geologists who work
in the oil and mining industries.  JPL and the planetary science
community have some growth and adaptation to do, to emphasize these
types, but there's nothing to prevent it from growing this way, it's
a natural direction.  JPL has also done work in microgravity
processing, and could neatly tie these two skills together, as
most microgravity processes don't become economical until we
can start tapping the abudant native materials in space, instead
of launching all the raw materials from earth.  Cost is highly
dependent on ore quality, ie the results of solar system prospecting.

There are many other aspects besides geology that also could be
interesting; eg the processing of large-scale plasmas in space
borrows directly from the current biggest application of space
science, the study of the near-earth space plasma environment
and its implications for satellite design.

>get basic operating costs in space down by 2 orders of magnitude.
>Then the market will do the rest.

But right now planetary science is operating without any feedback
from markets, real or potential.  That's why we haven't flown
a lunar orbiter -- there's not much basic science for it to do,
but it is one of the top-priority projects from a future-market
prospecting point of view.  Planetary science and the associated
native materials processing plays a central role in dropping costs
by orders of magnitude, leapfrogging the very slow trend in
launch cost reduction since the 1960's by opening up sources of
industrial supply off earth.

I'd point out that other parts of government scientific research
suffer from this rot, SSC being the most expensive, glaring
example.  (The astronaut program would also be an example but
most scientists have by now disowned it).


--
Nick Szabo                     [e-mail]

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

Date: 18 Mar 93  21:16:56
From: [e-mail]
Subject: Russians  ICBMs -> SLVs
Newsgroups: sci.space

Are any details on the design of former Soviet ICBMs available now?


--- Maximus 2.01wb

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

Date: 19 Mar 93 06:28:50 GMT
From: Dean Adams <[e-mail]>
Subject: SR-71 Maiden Science Flight
Newsgroups: sci.space

[e-mail] (Pat) writes:
 >Wouldn't some of the Dryden Pilots for the NASA SR-71  now have been
 >former AirFOrce  Recon Pilots?
They are NASA pilots.

 >I imagine it's just cheaper to get them on TDY or Assignment to
 >NASA then to send people through SR-71 flight school.
I expect the AF pilots had their own ideas for their careers.  :->

 >Actually, I once saw a picture of a two seat SR-71 Pilot trainer.
 >If that was de-commisioned,  it will be hard to train new SR-71 pilots.

Which is exactly why the SR-71B/#956 (NASA 831), is now living at Dryden.

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

Date: Fri, 19 Mar 1993 05:46:59 GMT
From: "Richard A. Schumacher" <[e-mail]>
Subject: Why use AC at 20kHz for SSF Power?
Newsgroups: sci.space

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
you're in orbit. Instead, NASA spent $20M and two years
on 20 kHz system development, and has a lot of paper sitting
on desks.

As for the difficulty of shielding scientific instruments
from 400 Hz noise: some EE better go tell those poor
fool astronomers who have been flying their instruments
in U-2s for 20 years that they're doing it all wrong...

(Oh no! Now they're doing the same thing in an SR-71!
Stop them before it's too late!)

20kHz power is a Boondoggle. A gold-plated, aerospace-
contractor's-wetdream, engineering-porkbarrel boondoggle.

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End of Space Digest Volume 16 : Issue 340
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