Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_4/V16NO466.TXT

Internet Message Format | 1993-07-13 | 27KB

Date: Sat, 17 Apr 93 05:11:49
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #466
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat, 17 Apr 93       Volume 16 : Issue 466

Today's Topics:
                            Guns for Space
                       How many read sci.space?
                How to read sci.space without netnews
                japanese moon landing/temporary orbit
                   japanese moon landing? (5 msgs)
               Moscow Aviation Institute summer school
                Orion drive in vacuum -- how? (2 msgs)
                          ORION space drive
            Portuguese Launch Complex (was:*Doppelganger*)
                     Quotation? Lowest bidder...
                Shuttle oxygen (was Budget Astronaut)
                     space news from Feb 1 AW&ST
             Two-Line Orbital Element Set:  Space Shuttle
       Washington Post Article on US-Russian Space Cooperation

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: 5 Apr 93 17:00:22 GMT
From: Dani Eder <[e-mail]>
Subject: Guns for Space
Newsgroups: sci.space

In reference to the limits of acceleration with guns launching solid
rockets as payloads.  Thiokol provided me with samples and data on
a reinforcement to solid motor grains for high accelerations.  Solid
motor propellants usually have a substantial percentage of
aluminum in the mix.  For example, the Space Shuttle SRBs are 16 percent
Aluminum.  The technique is to use a 'foamed aluminum' structure.
The structure looks like the inverse of a set of bubbles (an I suspect
some bubbling process is used to form it).  In other words, if you made
a bunch of bubbles in molten aluminum, then froze it, this is what
you get.  It forms a strong network of effectively aluminum wires in
all directions.  The remaining solid fuel mix is infiltrated into
the voids, and you get aluminum-reinforced solid propellant.  The
foamed-aluminum makes up about 6 percent of the total propellant,
so there is still aluminum particles in the bulk grain.  The major
improvement is the higher resistance to grain cracking, which is the
principal failure mode for solid propellant.

Dani Eder

--
Dani Eder/Meridian Investment Company/[phone](w)/232-7467(h)/
Rt.1, Box 188-2, Athens AL 35611/Location: 34deg 37' N 86deg 43' W +100m alt.

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

Date: 16 Apr 1993 15:11:47 -0400
From: Pat <[e-mail]>
Subject: How many read sci.space?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ross  Borden) writes:
|In article <1qjs1j$[e-mail]> [e-mail] (Pat) writes:
|>
|>
|>In the old days,  their used to be Arbitron stats'  that analyzed
|>the readership and posting volumes  by group  and user.
|>
|>They were available from UUNET.   That's how you check the
|>readership of Sci.space,  not some stupid  unscientific attempt
|>to  flood the newsgroup.
|>
|>I have abetter idea.  WHy don't we all reply directly to the
|>origanator  of this post,  and tell him we read sci.space ;-)
|>
|>
|>pat
|
|    Sigh.
|    I try to make a little joke, I try to inject some humour here
|and what happens?  In the immortal words of Foghorn Leghorn:
|
|    "I say, that was a _joke_, son."
|
|    I thought that the bit about McElwaine, not to mention the two
|smileys, would indicate to even the most humour impaired that I was
|JOKING.
>    Sigh.
>    (And will everyone who pat's suggestion (thanks bunches, pat)
>*please* stop sending me email.)
>
>-------------------------------------------------------------------------------
>|  I shot a man just to watch him die;    |     Ross Borden                   |
>|  I'm going to Disneyland!               |     [e-mail]            |
>-------------------------------------------------------------------------------


Now, I had put a Wink at the end of my suggestion indicating it was
intensely sarcastic.  I can't help it if everyone got all serious.

Ross.

    I never saw your original posting.  it dropped on the floor
somewhere.  I just saw the trickle down, thought it was intensely
stupid,  not knowing anything about the joke, mentioned arbitron
and left it with an equally stupid joke.  Bill in his ever increasing
devotion to thoroughness dug up  several  arbitron stats.

I myself think the arbitron stats are  severely methodologically impaired,
but are a good measure of proportion.  I don't think anyone
knows how many people read news anymore.

pat

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

Date: Fri, 16 Apr 1993 21:52:46 GMT
From: Mark Maimone <[e-mail]>
Subject: How to read sci.space without netnews
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mark Prado) writes:
>If anyone knows anyone else who would like to get sci.space,
>but doesn't have an Internet feed (or has a cryptic Internet
>feed), I would be willing to feed it to them.

    Kudos to Mark for his generous offer, but there already exists a
large (email-based) forwarding system for sci.space posts:  Space Digest.
It mirrors sci.space exactly, and provides simple two-way communication.

    TO SUBSCRIBE:
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Questions, comments to [e-mail]
--
Mark Maimone                phone: [phone] - 7698
Carnegie Mellon Computer Science    email: [e-mail]

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

Date: Sat, 17 Apr 1993 02:04:42 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: japanese moon landing/temporary orbit
Newsgroups: sci.space

[e-mail] (Ray Swartz (Oh, that guy again)) writes:

>The gravity maneuvering that was used was to exploit 'fuzzy regions'.  These
>are described by the inventor as exploiting the second-order perturbations in a
>three body system.  The probe was launched into this region for the
>earth-moon-sun system, where the perturbations affected it in such a way as to
>allow it to go into lunar orbit without large expenditures of fuel to slow
>down. The idea is that 'natural objects sometimes get captured without
>expending fuel, we'll just find the trajectory that makes it possible". The
>originator of the technique said that NASA wasn't interested, but that Japan
>was because their probe was small and couldn't hold a lot of fuel for
>deceleration.


I should probably re-post this with another title, so that
the guys on the other thread would see that this is a practical
use of "temporary orbits..."

Another possible temporary orbit:

--
Phil Fraering         |"Seems like every day we find out all sorts of stuff.
[e-mail]|Like how the ancient Mayans had televison." Repo Man

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

Date: 16 Apr 1993 18:55 UT
From: Ron Baalke <[e-mail]>
Subject: japanese moon landing?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Daniel Burstein) writes:

>A short story in the newspaper a few days ago made some sort of mention
>about how the Japanese, using what sounded like a gravity assist, had just
>managed to crash (or crash-land) a package on the moon.

The Japanese spacecraft, Hiten, crashed on the Moon last weekend.  For the
past three years it has made several lunar flybys and even did some
aerobraking experiments with Earth's atmosphere.  It was placed in lunar
orbit in February 1992, and I guess it finally ran out of fuel and was
unable to maintain its orbit around the Moon.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | The aweto from New Zealand
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/  |_|/       |_____|/                     | part vegetable.

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

Date: Fri, 16 Apr 1993 19:48:13 GMT
From: "Ray Swartz (Oh, that guy again" <[e-mail]>
Subject: japanese moon landing?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Daniel Burstein) writes:
>>A short story in the newspaper a few days ago made some sort of mention
>>about how the Japanese, using what sounded like a gravity assist, had just
>>managed to crash (or crash-land) a package on the moon.
>
>Their Hiten engineering-test mission spent a while in a highly eccentric
>Earth orbit doing lunar flybys, and then was inserted into lunar orbit
>using some very tricky gravity-assist-like maneuvering.  This meant that
>it would crash on the Moon eventually, since there is no such thing as
>a stable lunar orbit (as far as anyone knows), and I believe I recall
>hearing recently that it was about to happen.


The gravity maneuvering that was used was to exploit 'fuzzy regions'.  These
are described by the inventor as exploiting the second-order perturbations in a
three body system.  The probe was launched into this region for the
earth-moon-sun system, where the perturbations affected it in such a way as to
allow it to go into lunar orbit without large expenditures of fuel to slow
down. The idea is that 'natural objects sometimes get captured without
expending fuel, we'll just find the trajectory that makes it possible". The
originator of the technique said that NASA wasn't interested, but that Japan
was because their probe was small and couldn't hold a lot of fuel for
deceleration.

    This from an issue of 'Science News' or 'The Planetary Report' I
believe, about 2 months ago(?).


Raymond L. Swartz Jr. ([e-mail])
================================================================================
I read the newspaper today and was amazed that, in 24 hours, five billion
people could accomplish so little.
================================================================================

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

Date: Fri, 16 Apr 1993 20:24:56 GMT
From: Henry Spencer <[e-mail]>
Subject: japanese moon landing?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>allow it to go into lunar orbit without large expenditures of fuel to slow
>down. The idea is that 'natural objects sometimes get captured without
>expending fuel, we'll just find the trajectory that makes it possible". The
>originator of the technique said that NASA wasn't interested, but that Japan
>was because their probe was small and couldn't hold a lot of fuel for
>deceleration.

Actually, Hiten wasn't originally intended to go into lunar orbit at all,
so it indeed didn't have much fuel on hand.  The lunar-orbit mission was
an afterthought, after Hagoromo (a tiny subsatellite deployed by Hiten
during a lunar flyby) had a transmitter failure and its proper insertion
into lunar orbit couldn't be positively confirmed.

It should be noted that the technique does have disadvantages.  It takes
a long time, and you end up with a relatively inconvenient lunar orbit.
If you want something useful like a low circular polar orbit, you do have
to plan to expend a certain amount of fuel, although it is reduced from
what you'd need for the brute-force approach.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 16 Apr 1993 22:17:33 GMT
From: CLAUDIO OLIVEIRA EGALON <[e-mail]>
Subject: japanese moon landing?
Newsgroups: sci.space

> there is no such thing as a stable lunar orbit

Is it right??? That is new stuff for me. So it means that  you just can
not put a sattellite around around the Moon for too long because its
orbit will be unstable??? If so, what is the reason??? Is that because
the combined gravitacional atraction of the Sun,Moon and Earth
that does not provide a stable  orbit around the Moon???

 [e-mail]

[e-mail]

Claudio Oliveira Egalon

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

Date: Sat, 17 Apr 1993 01:59:45 GMT
From: Henry Spencer <[e-mail]>
Subject: japanese moon landing?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (CLAUDIO OLIVEIRA EGALON) writes:
>> there is no such thing as a stable lunar orbit
>
>Is it right??? That is new stuff for me. So it means that  you just can
>not put a sattellite around around the Moon for too long because its
>orbit will be unstable??? If so, what is the reason??? Is that because
>the combined gravitacional atraction of the Sun,Moon and Earth
>that does not provide a stable  orbit around the Moon???

Any lunar satellite needs fuel to do regular orbit corrections, and when
its fuel runs out it will crash within months.  The orbits of the Apollo
motherships changed noticeably during lunar missions lasting only a few
days.  It is *possible* that there are stable orbits here and there --
the Moon's gravitational field is poorly mapped -- but we know of none.

Perturbations from Sun and Earth are relatively minor issues at low
altitudes.  The big problem is that the Moon's own gravitational field
is quite lumpy due to the irregular distribution of mass within the Moon.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Fri, 16 Apr 1993 23:34:03 GMT
From: Steve Emmett <[e-mail]>
Subject: Moscow Aviation Institute summer school
Newsgroups: sci.space

I have attached a copy of an announcement I picked up during my trip to
Moscow last week.  I have several friends at the Moscow Aviation
Institute who have asked me to post this announcement.  (I have done
some editing, but the contents is unchanged from the original
announcement.)

For those of you not familiar with the Moscow Aviation Institute, it is
the leading Russian school of higher education dedicated to the training
of aircraft and spacecraft designers.  It specializes in airframe
design, powerplant design, control systems, and power systems.
Virtually all of the major former Soviet airframe designers (Tupolev,
Su, Iluchine, Migoyan, etc.) were schooled at MAI.

I had the opportunity to tour the two museums that are maintained at
MAI.  The aircraft include Mig23, Su 27, Yak 38, the cockpit of an
F-111(!), among others.  It was a fascinating and eye opening
experience, expecially given the fact that the museum was, until a year
or so ago, closed to virtually everyone.  I also had the opportunity to
see some of the experiments being conducted with plasma drive engines
for future space craft use.

If you have any questions about the Institute, or the program, I would
be glad to try and answer them.  The institute, and most of it's faculty
have e-mail addresses.  However, it takes about a day or so for the
receiver to get the message.  They are still a bit antiquated - but they
are rapidly changing!

Steve Emmett
[e-mail]

ps  please send any questions you have for me via e-mail.  George Mason
university has about a 2 week (!) delay in news feed delivery.


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

        MOSCOW INTERNATIONAL AVIATION SCHOOL

The aviation school "Poljot" (meaning Flight) is organized by the the
Moscow Aviation Institute, the prominent Russian Center of airspace
education and the foreign trade firm Poljot, well known in various
parts of the world for their quartz and mechanical wrist watches.

The course of studies will last only 50 days, but during this time
you will have the unique opportunity:
    - to listen to intensive courses on the main aviation
disciplines, the history and theory of techniques, and design of
airplanes;
    - to visit and get acquainted with the world known Russian
aviation firms - TU, MiG, Yak, Il and Su;
    - to meet and have discussions with famous aviation
scientists, engineers and pilots;
    - to visit the most interesting museums of unique aviation
techniques which were closed for many years to the public;
    - to see the International Airspace Show which will take
place in Moscow from 31 August through 3 September 1993;
    - to visit famous art museums, historical and architectural
monuments, theatres and concert halls;
    - to take part in sport competitions and have a great time
with new friends.

The Director of the school is Mr. Oleg Samelovich, a well known
Russian scientist, professor, general designer and the Chief of the
Airplanes Design Department of the Moscow Aviation Institute.  Mr.
Samelovich is one of the designers of the the Su-24, Su-25, and Su-27

The lectures are given in English, using a multi-media concept.  The
students are provided with all the necessary text books and
literature.  After the full course of studies are completed, the
student will receive a special certificate of graduation.

The cost of studies, including hotel, meals, excursions, theatres,
etc is $3500.

To apply for admission, send your application to:

109147 Moscow Marksistskaja 34
Foreign Trade Firm "Poljot"
274 00 13 (phone)
274 00 22 (FAX)
411989 POLEX SU (telex)

In your application, include your full name, address, date and place
of birth.  In addition, include complete passport information, as well
as a description of your education.

Upon receipt of this information, "Poljot" will immediately forward
to you an official invitation for obtaining a Russian entrance visa
as well as details on payment.

Should you require additional information, please do not hesitate to
contact us.

(signed)    O. Samelovich

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


--

Steve Emmett                 [e-mail]
------------------------------------------------------------------
CSI/Physics, George Mason University

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

Date: 16 Apr 1993 16:18:56 -0400
From: "James P. Goltz" <[e-mail]>
Subject: Orion drive in vacuum -- how?
Newsgroups: rec.arts.sf.science,sci.space

  Background: The Orion spacedrive was a theoretical concept.  It
would be a drive using thermonuclear explosions to drive a spacecraft.
The idea was that you'd detonate devices with somewhere from one to
ten megatons yield behind a "pusher plate" attached to the main
spacecraft.  The shock wave from the explosions would transfer
momentum to the ship.

  Now, in an atmosphere I can see this.  The energy of the explosion
heats the atmosphere, which expands explosively and slams a shock wave
into the pusher plate.  But in a vacuum, only two things I can see are
going to hit the plate: fission/fusion products (barium, krypton,
helium, neutrons, evaporated bomb casing) and electromagnetic
radiation (gammas mostly, some light/heat from irradiated fission
products).

  Would this work?  I can't see the EM radiation impelling very much
momentum (especially given the mass of the pusher plate), and it seems
to me you're going to get more momentum transfer throwing the bombs
out the back of the ship than you get from detonating them once
they're there.

  I must be missing something.  Would someone enlighten me via email?

  Thanks.

--
    --Jim

---
Jim Goltz                    AlterNet Engineer               [e-mail]

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

Date: Fri, 16 Apr 1993 20:28:17 GMT
From: Henry Spencer <[e-mail]>
Subject: Orion drive in vacuum -- how?
Newsgroups: rec.arts.sf.science,sci.space

In article <[e-mail]> [e-mail] (James P. Goltz) writes:
>  Would this work?  I can't see the EM radiation impelling very much
>momentum (especially given the mass of the pusher plate), and it seems
>to me you're going to get more momentum transfer throwing the bombs
>out the back of the ship than you get from detonating them once
>they're there.

The Orion concept as actually proposed (as opposed to the way it has been
somewhat misrepresented in some fiction) included wrapping a thick layer
of reaction mass -- probably plastic of some sort -- around each bomb.
The bomb vaporizes the reaction mass, and it's that which transfers
momentum to the pusher plate.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Sat, 17 Apr 1993 00:03:39 GMT
From: nathan wallace <[e-mail]>
Subject: ORION space drive
Newsgroups: sci.space

An excellent reference for non-technical readers on the ORION system is
"The Starflight Handbook", by Eugene Mallove and Gregory Matloff, ISBN
0-471-61912-4. The relevant chapter is 4: Nuclear Pulse Propulsion.

The book also contains lots of technical references for the more academically
inclined.

Enjoy!
---
C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/
C/    Nathan F. Wallace                   C/C/           "Reality Is"         C/
C/    e-mail: [e-mail]   C/C/    ancient Alphaean proverb    C/
C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/C/


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

Date: 16 Apr 1993 22:25:46 GMT
From: CLAUDIO OLIVEIRA EGALON <[e-mail]>
Subject: Portuguese Launch Complex (was:*Doppelganger*)
Newsgroups: sci.space

> Portugese launch complex were *wonderful

Portuguese launch complex??? Gosh.... Polish are for American in the
same way as Portuguese are for Brazilians (I am from Brazil). There is
a joke about the Portuguese Space Agency that wanted to send a
Portuguese  astronaut to the surface of the Sun (if there is such a thing).
How did they solve all problems of sending a man to the surface of the
Sun??? Simple... their astronauts travelled during the night...

 [e-mail]

[e-mail]

Claudio Oliveira Egalon

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

Date: Fri, 16 Apr 1993 22:22:40 GMT
From: [e-mail]
Subject: Quotation? Lowest bidder...
Newsgroups: sci.space

Can someone please remind me who said a well known quotation?

He was sitting atop a rocket awaiting liftoff and afterwards, in answer to
the question what he had been thinking about, said (approximately) "half a
million components, each has to work perfectly, each supplied by the lowest
bidder....."

Attribution and correction of the quote would be much appreciated.

Clive Trotman

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

Date: 16 Apr 1993 15:06:44 -0400
From: Pat <[e-mail]>
Subject: Shuttle oxygen (was Budget Astronaut)
Newsgroups: sci.space

I thought that under emergency conditions,  the STS  can
put down at any good size Airport.  IF it could take a C-5 or a
747, then it can take an orbiter.   You just need a VOR/TAC

I don't know if they need ILS.

pat

ANyone know for sure.

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

Date: Fri, 16 Apr 1993 23:10:29 GMT
From: "Richard A. Schumacher" <[e-mail]>
Subject: space news from Feb 1 AW&ST
Newsgroups: sci.space

>Marshall is investigating a small but odd pressure rise in one SRB
>during the Jan 12 Endeavour launch.  It lasted only three seconds and
>the thrust difference between the two SRBs was not enough to cause
>nozzle gimballing.  The SRB casing shows no abnormalities.

Is this the one that had the {wrench|pliers} found inside after
recovery?

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

Date: Sat, 17 Apr 1993 03:06:07 GMT
From: TS Kelso <[e-mail]>
Subject: Two-Line Orbital Element Set:  Space Shuttle
Newsgroups: sci.space

The most current orbital elements from the NORAD two-line element sets are
carried on the Celestial BBS, [phone], and are updated daily (when
possible).  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, 2400, 4800, or 9600 bps using
8 data bits, 1 stop bit, no parity.

Element sets (also updated daily), shuttle elements, and some documentation
and software are also available via anonymous ftp from archive.afit.af.mil
(129.92.1.66) in the directory pub/space.

STS 56
1 22621U 93 23  A 93105.58333333  .00090711  00000-0  25599-3 0   249
2 22621  57.0029 144.8669 0004136 304.2989 134.3206 15.92851555  1179
1993 023B
1 22623U 93 23  B 93103.37312705  .00041032  00000-0  11888-3 0    86
2 22623  57.0000 155.1150 0004422 293.4650  66.5967 15.92653917   803
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]                    Air Force Institute of Technology

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

Date: Fri, 16 Apr 1993 17:04:35 GMT
From: "Charles J. Divine" <[e-mail]>
Subject: Washington Post Article on US-Russian Space Cooperation
Newsgroups: sci.space

Reported yesterday in the Washington Post (Kathy Sawyer, writer):

The article plays down the Russian role in US space.

Gibbons (science advisor to Clinton) sent Goldin a letter indicating
NASA should not limit redesign options to those compatible with Mir
orbit.

The White House thinks expectations for Russian cooperation have been
raised too high.

The article reports that some think the spending and schedule limits
for space station are so stringent that the redesign is nearly
impossible.  That's why some think Goldin has begun looking at
Russian hardware.

Goldin states NASA will present all options to the administration
which will then have decision making power.

Goldin and the White House have totally ruled out using Energia to
boost the station.
--
Chuck Divine

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

End of Space Digest Volume 16 : Issue 466
------------------------------