Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO500.TXT

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Date: Fri,  4 Dec 92 09:48:55
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #500
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri,  4 Dec 92       Volume 15 : Issue 500

Today's Topics:
    Buying Clark's *Ignition!* (was Re: Good Book on Rocket Fuel)
       Galileo through SAA (was Re: Space probe to pass Earth)
   NASA has 5 hand grenades still on the moon from Apollo missions
                         NSSDC Data on CD-ROM
                     Shuttle replacement (5 msgs)
                    Space_nz. Information Bureau.
                      Space probe to pass Earth
                       Spherical Space stations
                             swift finder
       Terminal Velocity of DCX? (was Re: Shuttle ...) (2 msgs)
         Voyager's "message"... What did it *say*?!? (2 msgs)
                           Voyager message
                What is the SSTO enabling technology?

    Welcome to the Space Digest!!  Please send your messages to
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 3 Dec 92 04:17:50 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Buying Clark's *Ignition!* (was Re: Good Book on Rocket Fuel)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Thomas Clarke) writes:
> I recommend the book:
> _Ignition! An informal history of liquid rocket propellants._
> by John Clark  (1972, Rutgers Univ Press)

I've said it before and I'll say it again:  I want to own a copy of
this book! Anybody know where I can buy a copy?  (I do know of several
libraries that have it, so I can *read* it whenever I want.)

Rutgers let it go out of print.  I've suggested to Dover that they
reprint it but have received no response.

     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     [e-mail]
   -   -       Internet:  [e-mail]
     ~         SPAN/Hepnet:      43011::HIGGINS

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

Date: 3 Dec 92 17:19:51 GMT
From: Steve Derry <[e-mail]>
Subject: Galileo through SAA (was Re: Space probe to pass Earth)
Newsgroups: sci.space

So Galileo will pass over the South Atlantic at 190 nm next Tuesday morning.
Does anybody know whether it will fly through the SAA (South Atlantic
Anomaly)?  Will it matter if it does?  Since it is designed to fly near
Jupiter, I guess it is designed to handle harsh radiation environments...

On a different note, is there any way the Probe Relay antenna could be used
to transmit data if the HGA fails to open?

--
Steve Derry
<[e-mail]>

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

Date: 3 Dec 92 13:40:40 GMT
From: Gary Coffman <ke4zv!gary>
Subject: NASA has 5 hand grenades still on the moon from Apollo missions
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>
>The propellant in modern firearms does not need oxygen from the air to work,
>the oxidizer is built in.  Oxygen from the air is negligible in helping
>to fire a gun.
>
>However, having said that, I read that black powder (the old style gunpowder,
>not used in most modern firearms) will not ignite in a vacuum, NOT because
>it needs the oxygen from the air (it is built in), but because it needs the
>pressure.  It works just fine in an atmosphere of argon or any other inert gas.

Black powder will ignite just fine in vacuum. It generates it's own
pressure in the confines of a cartridge or muzzleloading firearm to
accelerate the burn rate to sufficient levels to generate the 50,000
PSI working pressure of a firearm.

Black powder, unlike smokeless powder, can explode when unconfined.
It's rated as an explosive while smokeless powder is rated as a
combustible solid. It may be that *unconfined* black powder would
not explode in vacuum and instead just burn vigorously, as it often
does down here in atmosphere when spread out enough. But it would
certainly work as advertised in the confined space of a firearm.

There's a feedback mechanism at work with burning generating gases
that increase pressure which then increases burn rate which generates
more gases, etc. Pressure stops increasing when the projectile moves
fast enough to increase chamber volume faster than burning generates
additional gas.

Gary

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

Date: 3 Dec 92 13:17:00 GMT
From: dan herpst <[e-mail]>
Subject: NSSDC Data on CD-ROM
Newsgroups: sci.space,alt.sci.planetary,alt.cd-rom

In article <[e-mail]>, [e-mail] writes...
>In article <[e-mail]>, [e-mail] (Robert J. Kinder) writes...
>
>Since you can get all 12 of the Voyager CD-ROMs for only $86, I'd suggest
>that you get the whole set.

     Where can I get these for $86???

     I would love to get a set!

Thanks,
Dan Herpst
716-588-4973
--------------------------------------------------------

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

Date: 3 Dec 92 14:44:24 GMT
From: Greg Moore <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <qg#[e-mail]> [e-mail] (Greg Moore) writes:
>
>>    This comment bears a little explaining I think.  What exactly has
>>beed cancled that has actually been scheduled...
>
>Check out the table in the Nov. 12, 1990 issue of Avation Week on Page 27.
>
    Thanks, this is the sort of info I was looking for.

>In ten years of operation this is the first year where Shuttle has gotten
>even close to projected flight rates.
>
    Ayup, 8 scheduled flights, 8 flown, that's pretty close.  Last
year I believe slipped a total of 1 flight.

>>However, if something DOES go wrong, or for some reason you want a
>>person on sight, then the shuttle wins.
>
>Maybe even not then. It depends on the cost of failure.
>
    Agreed, but since we were discussing Hubble and other unique
items, I'd say the cost is high.

>>For something like Hubble, or
>>some other unique satellites, I'd prefer the Shuttle.
>
>One reason Hubble is unique is that Shuttle eats almost a third of
>NASA's budget. I hope you consider this when measuring Shuttle utility.
>
    As others have pointed out, this reasoning is specious.  Hubble
is unique because of its design.

>If YOU where paying for Hubble, which would you pick?
>
    Hmm, let's see, I want to repair the optics on it.  My requirements
are several days on-orbit time, plenty of consumables for 3-4 spacewalks,
possibly a 3rd astronaut out there, room to carry parts.  Let me look
at my options:
    Ariane: Hmm, no manned option.
    Atlas: No manned option (admittedly yet if you ahve your way) but
does a Soyuz carry enough consumables, I think not.
    Soyuz ala Russia... same problems above, though it is flyable now.
    DC-1:  Not yet.  Even then will it have the on-orbit time.  My
understanding is that it's designed for SHORT trips to space.
    Shuttle: Hmm, flying, can carry what I need.  Sure, you can argue
it costs more than other optins, but since other optins CAN'T do the job
that is a moot point.  I'll pick shuttle thank you.

>>    Allen, they haven't made a profit in 6 years (since Challanger).
>
>Largely because they are forced to compete with government subsidized
>competition.
>
    Gee, not US-Government subsidized competittion, which is what
I thought we were arguing about.  Hell, if I want cheap, I'll go Long
March.  But for various reasons (some personal some political) I don't
want to.

>The point still remains that the commercial providers are REDUCING the
>cost of access to space; Shuttle increases it. Commercial launchers spend
>investors money, Shuttle spends MY money. Given a choice between a cheaper
>option which costs me nothing and a more expensive one I need to pay for
>I would pick the former. How about you?
>
    And which option costs you NOTHING? If you want to fly a payload
you still need to pay something!
    Shuttle costs more.  It is not actively INCREASING the cost to
space.  I do agree that if DC-1 works, costs may be reduced.

>>>But what would have happened if we developed a commercial based infrastructure
>>>back in 1980? Much furthur I'll bet.
>
>>Let's argue today, not the past.
>
>One thing we need to do to make progress is understand the mistakes of
>the past and then have the courage to correct them.
>
    Agreed, learn from your mistakes so as not to repeat them.  However,
wishful thinking won't make the CURRENT reality go away.

    Just so that you are aware Allen, I AM a supporter of DC-X, even if
it goes down in flames.  It is innovative, cheap, and we stand to learn alot
from it, whether or not it succeeds.  Even if the DC-1 flys and costs only
come down incrementally I think the program has succeeded in some ways.

    However, I also think the shuttle currently has a role and we cannot
abandon it UNTIL we have other reliable solutions in place.

>  Allen
>
>--
>+---------------------------------------------------------------------------+
>| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
>|  [e-mail]     |  nothing undone"                                       |
>+----------------------143 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 3 Dec 92 14:47:36 GMT
From: Greg Moore <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>   Finally, I can't imagine that NASA paid to have the Apollo 19 booster
>   shipped to KSC when they knew that it would never fly. I doubt even
>   Apollo 18 would have made the barge-ride.
>
    I deleted the rest about which Saturn V is at KSC since I don't know,
but I believe the Saturn V designated for Apollo 18 was barged in.  It was
used to launch Skylab I.

>   -Brian
>

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

Date: 3 Dec 92 14:12:59 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>>... will have to be built to keep the probability of such failures low.
>>>That means, as with airliners, careful analysis of fatigue lives of parts
>>>and inspection/replacement schedules set up to avoid problems.  (It also
>>>means, as with airliners, that there will probably be an occasional crash
>>>due to unanticipated problems.)
>>
>>Yes, I agree with this. My question is whether any space launch system
>>can accumulate enough flight hours to make any of this analysis meaningful.
>
>If a jet fighter can, it should be possible with a DC-1.

Jet fighters don't cost $10 million a flight. I don't believe that
number for a minute, but granting it for this argument, that means
that a hundred flights would cost $1 billion dollars. The same number
of flights in a jet fighter costs about $900,000 dollars. Quite a
difference.

>>It seems to me that the launch requirement for something of the DC class
>>is small enough that there will only be a few built, and those flown
>>fairly infrequently...
>
>If you use a DC as a straight replacement for existing launchers, sure.
>But there is no real requirement to replace existing launchers.  The whole
>point of building something radically different, e.g. the DCs, is to try
>to open up new markets.  Given this, it's difficult to predict numbers and
>flight rate... but it could be large.

I agree that there is no real requirement to replace existing launchers.
Their cost is not the dominant factor in space systems currently being
deployed. As I remarked to Allen, "Build it and they will come." is
movie myth. There should be an identified market for this proposed
spaceship before it is built. That's just good business sense.

I haven't seen any mention of customers lining up to buy these spaceships.
Airliners aren't normally built without firm orders in hand. The only
money going into this program seems to be coming from the US taxpayer.
I don't find that evil, as Allen normally does, but it isn't the way
commercial development is done. This is a government funded R&D operation,
not commercial space development. Some of the technology developed may
eventually find it's way into a commercial product *if* a market develops
for the product.

Gary

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

Date: 3 Dec 92 16:31:20 GMT
From: Doug Mohney <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Carl Hage) writes:

>Come on, it doesn't make sense to fly DC-1 from John Wayne airport.
>Airliners fly from John Wayne because they are taking passengers to Las
>Vegas or whatever. DC-1 is taking freight or crew from Earth to space. It
>is cheaper to ship the payload to the DC-1 launch complex rather than
>build multiple launch complexes, or operate out of existing airports. You
>can't get a non-stop flight from John Wayne to Antarctica, so why would
>anyone expect to get a non-stop flight from John Wayne to orbit?

Depends. Some earlier speculation on using DC-1 for sub-orbital hops which
would bring new meaning to the word "absolutely, positively overnight."

>From an ecomonic point of view I see no reason to have more than one
>launch complex (at least on a continent). One complex could support all
>the capacity required.  The maintenance and support from a central
>facility would be much better than distributed facilities. A single large
>LOX/LH2 manufacturing plant can be built, and fueling can be done at the
>pad by transferring the fuel to the pads via rail car.

Pretty simple economics. If you have a time-critical need to be met in orbit,
you may want to have the closest DC-1 launch site to be within a couple hours
driving time (to move cargo by truck), rather than have to move it to the
central location.

Similarly, if you are bringing cargo down from orbit (wave-hand, some exotic
materials better produced in space than earth), delivery would be more
convenient closer to the factory.

>I suppose the military would want thier own launch complex, although
>probably only for political reasons, not from economic or security reasons.
>It would make more sense to have a small secured area within a large
>commercial complex.

Nope. The Air Force's DC-1 will probably be stuck in Nevada out with the other
"black" equipment, for rapid deployment and away from prying eyes.


                 Play in the intelluctual sandbox of Usenet

  -- >                  [e-mail]                        < --

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

Date: Thu, 3 Dec 1992 13:25:23 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <qg#[e-mail]> [e-mail] (Greg Moore) writes:
>
>>    Allen, they haven't made a profit in 6 years (since Challanger).
>
>Largely because they are forced to compete with government subsidized
>competition.

So jump on the French, NASA is out of the commercial satellite launching
business. Shuttle is not competing for the commercial launch business.
It *should* be because it would lower science costs by sharing the
lift capacity of the Shuttle system, but that's a different issue.

>The point still remains that the commercial providers are REDUCING the
>cost of access to space; Shuttle increases it. Commercial launchers spend
>investors money, Shuttle spends MY money. Given a choice between a cheaper
>option which costs me nothing and a more expensive one I need to pay for
>I would pick the former. How about you?

Since the only *customer* for Shuttle launches is the government, you
pay for it. If that same customer moves all it's payloads to commercialized
old ICBMs, you *still* pay for it, *plus* a profit for those commercial
investors. You don't pay for commerical launches of commerical payloads
*now*, except in subsidy  costs on those old ICBM designs. That's not
even in the equation. The customer drives all costs by his demands for
launch services. Launch services are currently a minor part of space activity
costs and few commercial payload operators are crying out for cheaper lift
to make them profitable. They're much more interested in *reliable* delivery
of their payloads to the proper orbit, something Pegasus hasn't demonstrated
yet. Commercial and science payload costs, and ground support cost for those
payloads, dominate space systems costs. Hubble cost as much as a new Orbiter
to build and continues to incur operating costs. The $350 million it cost to
launch it is not the major cost of the system. If it had ridden a $220 million
upgraded Titan, the difference would have been minor, and we'd still need
Shuttle capability to fix it.

Gary

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

Date: 3 Dec 92 05:27:58 GMT
From: Spacelink <[e-mail]>
Subject: Space_nz. Information Bureau.
Newsgroups: sci.astro,sci.space.shuttle,sci.space

Space_nz is a Space Information Bureau based in New Zealand.  Our aim is
to supply answers to people's questions whether they be simple or complex
on the history of human accomplishments in space.

You can contact us through our Email address of [e-mail],
or by writing to Spacelink at PO Box 331402, Takapuna, Auckland 9, New Zealand,
(Please enclose an SASE), or by Fax on 64-9-8494282.

Please do not Post Articles on the Net for us to answer. Email and Standard
Post are the recomended ways.

This is a free service for the curious, supplied by a team of voluntary
Spaceflight enthusiasts.

--
DOMAIN:  [e-mail]
SNAIL:   PO Box 331402, Takapuna, Auckland 9, New Zealand
FAX:     [phone]

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

Date: 3 Dec 92 16:37:39 GMT
From: Pawel Jalocha <[e-mail]>
Subject: Space probe to pass Earth
Newsgroups: sci.space

>>     Scientists plan to use the pass by the atomic-powered, $1.4 billion
>> spacecraft to calibrate the probe's instruments by using the various
>> sensors and cameras to study and photograph the Earth and moon.

>And on a 'whine' note, once again the press trying to scare ignorant fools by
>stating that the spacecraft is atomic-powered.  Was that reference really
>necessary in the context of the article?  I think not!

I think this notice is there just to make some fools believe that Galileo
moves through space thanks to it's atomic power... in everyday's life
"atomic-powered" rocket means "a rocket with atomic thrust", does it ?

Pawel

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

Date: Thu, 03 Dec 92 17:54:42 EST
From: Tom <[e-mail]>
Subject: Spherical Space stations

>Spheres, on the other hand, might be manufactured on earth, a number at
>a time, as large as football fields, and shuttled up. Reinforcing and
>insulative materials would ride up compressed, ie - honeycomb, resins,
>foils, and applied to a surface from inside, and perhaps outside.

[more advantages of spheres]

Wouldn't spheres have the (dis)advantage of no tidally preferred direction?
Meaning, depending on your preference, that it could rotate to any orientation
preferred, or that station-keeping would be more difficult?

It seems like the problems with atmospheric drag would be reduced, as well.
More aerodynamic, smaller cross-section/volume, and, for the military
minded, easier to radar-cloak :-)

-Tommy Mac
-----------------------------============================================
Tom McWilliams              | What a tangled web we weave, when at   ". |
[e-mail]      |              ,  .first we .practice .*'  .|
[phone] -or- 353-2986|            '. '  . . to decieve    ,      |
a scrub Astronomy undergrad | After that, the  ,          +             |
at Michigan State University| improvement is tremendous! '.  , .'       |
------------------------------===========================================

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

Date: 3 Dec 92 16:10:18 GMT
From: Dave Hopkins <[e-mail]>
Subject: swift finder
Newsgroups: sci.space,sci.astro

In article <[e-mail]> Earl
W Phillips, [e-mail] writes:
>I scanned it to a .gif, uuencoded it & posted it here. I
>didn't test it, so let me know if it's ok!


Worked alright for me.

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

Date: 3 Dec 92 14:37:59 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Josh 'K' Hopkins) writes:
>[e-mail] (Gary Coffman) writes:
>
>>To shut me
>>up, all you need to do is agree to launch and land this thing away from
>>major population centers. It's not an airliner, and it likely can never be
>>an airliner. If it's a cheap launcher that ocasionally crashes or goes
>>boom in an uninhabited spot, that's good enough for me.
>
>DC isn't an airliner with wings and jets, but it's not a rocket with low
>margin engines and flight history of zero either.  It's something in between.
>To shut us up, you're going to have to show us why, given reasonable estimates
>of vehicle reliablity, you require it to live up to rocket standards and not
>airliner standards.  I think most of us agree that the RSO for a rocket is an
>important job, but that the current accident rate of airliners doens't
>necessitate them.  Just why can't a launcher be an airliner anyway?


The proposed DC *is* a rocket, it *is* a low margin system as any
SSTO has to be, and it has exactly *zero* flight history. It will
use throttleable engines with variable geometry *based* somewhat
on RL-10 technology at first, but radically new and never flight
tested. Later it intends to use aerospike engine designs that have
*never* been tested, even on the ground. It will be difficult for
it to live up to rocket standards of reliability, much less airliner
standards of reliability. This is radically new engine and control
technology being pioneered on a very marginal flight article. The
cost and reliability levels being bandied about have no basis other
than wishful thinking.

I hope they eventually get it to work, but don't book tickets just
yet. For the amount they intend to spend on the prototype we could
have a new Shuttle Orbiter. Now I'd rather see some X plane work
out of the government than a new Orbiter so I'm not complaining about
the cost, but this isn't some commercial venture, this is a government
funded R&D project right out on the *edge* of spaceflight capability.
If it were a straightforward safe and sane sure thing, with customers
lining up to sign contracts, it wouldn't *need* government funding.

Gary

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

Date: 3 Dec 92 13:55:33 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>... It's not an airliner, and it likely can never be an airliner....
>
>The FAA, which legally defines "airliner" for purposes of US aviation,
>reportedly disagrees.

"Reportedly" they have said they will *consider* the question when the
*proposed* spacecraft actually has sufficient *flight* experience to
*prove* it's claims of low risk. They are letting MacDD go through the
initial paperwork steps *leading* to certification. Whether they will
*suspend* most of their flight safety rules in order to *certify* the
proposed spaceship is another question altogether.

Most likely, going through the process *successfully* will allow the
proposed spaceship to forego *some* of the range safety rules for
current generation missiles and spacecraft. I think everyone, including
MacDD employees I corresponded with, would be very surprised if they got
an ordinary airliner certification out of the process.

Everyone except Jeremy Rifkin would be *delighted* if they *earned*
relaxed flight rules for the proposed DC-1, but it's sure to be tied
up in court for years in the unlikely event they *do* get such certification.

Gary

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

Date: 3 Dec 92 04:10:18 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Voyager's "message"... What did it *say*?!?
Newsgroups: sci.astro,sci.space

In article <0h_2![e-mail]>, [e-mail] (Michael V. Kent) writes:
> In article <[e-mail]> [e-mail] (Bradford B. Behr) writes:
>
> This whole explanation reminds me of Stonehenge and the Pyramids.  I can just
> picture an alien museum guide:
>
> "Creatures from Earth built this craft millions of years ago as an offering
> to their gods.  Urban legend has it that these strange markings have some
> relation to the spin-flip transition of hydrogen, but that is likely just
> a legend."

Some years ago astronomer Greg Ruffa drew a cartoon that showed an
alien putting the Voyager record on a turntable.  He gestures toward
the spacecraft as he says to another alien, "These days it seems like
ALL the albums come with some goofy packaging gimmick!"

Bill Higgins, Beam Jockey              | Comet Swift-Tuttle is
Fermi National Accelerator Laboratory  | Mama Nature's way of
Bitnet:           [e-mail]  | saying it's time to
Internet:       [e-mail]  | get off the planet.
SPAN/Hepnet:           43011::HIGGINS  |   --Dale Amon

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

Date: 3 Dec 92 17:30:31 GMT
From: "M. Otto, \"Virtual Prisoner of the VAX\"" <[e-mail]>
Subject: Voyager's "message"... What did it *say*?!?
Newsgroups: sci.astro,sci.space

In article <[e-mail]>, [e-mail] (Bill Higgins-- Beam Jockey) writes:
> In article <0h_2![e-mail]>, [e-mail] (Michael V. Kent) writes:
>> In article <[e-mail]> [e-mail] (Bradford B. Behr) writes:
>>
>> This whole explanation reminds me of Stonehenge and the Pyramids.  I can just
>> picture an alien museum guide:
>>
>> "Creatures from Earth built this craft millions of years ago as an offering
>> to their gods.  Urban legend has it that these strange markings have some
>> relation to the spin-flip transition of hydrogen, but that is likely just
>> a legend."
>
> Some years ago astronomer Greg Ruffa drew a cartoon that showed an
> alien putting the Voyager record on a turntable.  He gestures toward
> the spacecraft as he says to another alien, "These days it seems like
> ALL the albums come with some goofy packaging gimmick!"

I remember reading an SF story some time back about an alien spacecraft
showing up, and dumping Pioneer 10 on the White House lawn.  The aliens
tell the protagonists "Keep your toys in your own backyard; next time
there will be a fine for littering."

--
         __ ____ __      [e-mail]
 /|/|   / / / / / /  A virtual prisoner of the VAX     // I'm sorry; my karma
/   |. /_/ / / /_/  at The University of North Texas \X/  ran over your dogma
                             Denton, USA

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

Date: Thu, 3 Dec 92 15:10:53 -0600
From: [e-mail] (Phil G. Fraering)
Subject: Voyager message

\Some years ago astronomer Greg Ruffa drew a cartoon that showed an
/alien putting the Voyager record on a turntable.  He gestures toward
\the spacecraft as he says to another alien, "These days it seems like
/ALL the albums come with some goofy packaging gimmick!"

Was he the one who came up with the one about why they haven't
made contact? Something about how the aliens got the record from
one of the pioneer or voyager probes, and they're scared if they
show up they'll have to buy ten more at regular club prices...

\Bill Higgins, Beam Jockey              | Comet Swift-Tuttle is
/Fermi National Accelerator Laboratory  | Mama Nature's way of
\Bitnet:           [e-mail]  | saying it's time to
/Internet:       [e-mail]  | get off the planet.
\SPAN/Hepnet:           43011::HIGGINS  |   --Dale Amon

How do you do the varying sig bit?

--
Phil Fraering
"...drag them, kicking and screaming, into the Century of the Fruitbat."
<<- Terry Pratchett, _Reaper Man_
PGP key available if and when I ever get around to compiling PGP...

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

Date: Thu, 3 Dec 1992 12:27:28 GMT
From: Gary Coffman <ke4zv!gary>
Subject: What is the SSTO enabling technology?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Brad Whitehurst) writes:
>
>>>RL-10s seem to do just fine.
>
>>    But are they reused?
>
>Each RL-10 is tested with something like 20 starts and stops. There is
>nothing in their design which prevents starting and stopping  an arbitrary
>number of times.
>
>RL-10's have been started, stopped, and re-started in space several times.
>There is no reason they can't be re-used.

I think the real questions are, will they be reliably and repeatedly
throttlable, and will the variable geometry nozzle work reliably and
repeatedly? These are new features for the RL-10 varient.

Gary

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


From: Thomas Clarke <[e-mail]>
Newsgroups: sci.space
Subject: Good Book on Rocket Fuel
Message-Id: <[e-mail]>
Date: 3 Dec 92 13:15:47 GMT
Article-I.D.: cs.1992Dec3.131547.22712
Sender: News system <[e-mail]>
Organization: University of Central Florida
Lines: 26
Source-Info:  Sender is really [e-mail]
Source-Info:  Sender is really [e-mail]

I recommend the book:
_Ignition! An informal history of liquid rocket propellants._
by John Clark  (1972, Rutgers Univ Press)

It discusses the history of same beginning with Tsiolokovsky (sp?)
and Dewar right up to the 60's.

Much about the foibles of nitric acid - it was tamed when adding
6% HF to it was discovered to passivate steel and aluminum tanks.

Also exotics like FClO3 which apparently is fairly safe to handle.

Curiosities: under right conditions Teflon will burn with water
CFF2n + H2O -> CO and 2HF exothermically - weired hybrid?

Style is informal - one chapter title is "Peroxide, Always a Bridesmaid"

A good read.



--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
[phone], FAX: [phone], [e-mail]

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End of Space Digest Volume 15 : Issue 500
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