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Subject: SPACE Digest V11 #274

SPACE Digest                                     Volume 11 : Issue 274

Today's Topics:
          Re: Teenage Mutant Ninja Tomatoes
               A brief survey.
              Re: Fermi Paradox
              Project HARP and Dr. Bull
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Date: 16 Apr 90 18:44:00 GMT
From: deimos.cis.ksu.edu!uafhp![e-mail]  (Brian L. McCormick)
Subject: Re: Teenage Mutant Ninja Tomatoes

In article <[e-mail]>, [e-mail] (Peter Scott) writes:
> How about that announcement from NASA backpedalling on the possibility
> of the tomato seeds having mutated into toxic forms from the extra
> cosmic radiation they underwent?  The news station I was watching showed
[stuff zapped]
> But anyway, what kinds of mutations might we expect, given the
> especially energetic particles these seeds had to deal with?

One thing that struck me about this incident was when NASA officials
said that they wouldn't have any problem with eating a tomato from one
of these plants.  Excuse my paranoia, but I don't think I would.  It
strikes me that the fruit of most members of the genus Solanum (of which
the tomato is a member) contains a poison, solanin.  I would be worried
that a relatively minor mutation had occured that would render the fruit
poisonous.  Does anyone know what the actual likelihood of such a mutation
is?  Am I justified?

-------------------------------------------------------------------
Brian McCormick
[e-mail]
I deny being in any way affiliated with the College of Engineering.
-------------------------------------------------------------------

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Date: 17 Apr 90 05:39:11 GMT
From: zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!jarthur![e-mail]  (Todd Courtois)
Subject: A brief survey.

Fellow usenetters:

Sorry to disturb this illustrious newsgroup, but I am hoping that you can
help me.  Currently I am working on a research paper which asks the "simple"
question, "Why are there disproportionally few women in math and science?"

So how can you help me?  Well, below are just a few short questions with
standardized answers.  Both males and females are encouraged to reply, but
note that we will only accept one reply per username.  Please send your
replies to one of the following addresses :

[e-mail]
[e-mail]
uunet!jarthur!tcourtoi

Please put "SURVEY" in the subject line.

Note that following the questionnare is a sample e-mail answer.  Please
follow this format EXACTLY (it isn't difficult) because we are going to
process these through the computer, and it's going to reject anything that
isn't standard (thus your views won't count).

Questions:

1. Are you female or male? F M

2. Are you a scientist, engineer, mathematician or computer scientist? Y N
   (This includes any technical area requiring at least a bachelor's
     degree, and programmers or technical support staff).

3. Do you feel you've been discriminated against in hiring, promotion,
   recognition, etc. because of your gender?  Y N

4. In your opinion, which sex receives preferential treatment in hiring,
   promotion, recognition, etc. in your profession?   F M

5. Do you feel you are treated the same as people of the opposite sex
   with similar background and qualifications?  Y N

6. In your opinion, is less gender bias apparent in your profession
   than in other, non-technical professions?  Y N

7. Do you feel inferior in technical ability (programming skill, math
   ability, design creativity) to your counterparts of the opposite sex? Y N
    (NOTE this means *inherent ability*, NOT training-- see next question).

8. Do you feel that your educational background or training was less
   strong than your peers' of the opposite sex? Y N

9. Do you feel that, in general, there is a bias against women in your
   profession?  Y N

10. Do you feel women sacrifice their careers for family more often/more
    severely than men?  Y N


Sample Answer reply (just send an e-mail message which has this format):

M Y Y M Y Y Y N N N


Note that there are ten questions and ten answers.  Each answer is only
one upper case letter.
Any messages which do not follow this format will be destroyed.
Please do not include .sig files or any text but the answers.

Thanks for your cooperation!  In a few weeks when all the replies have been
processed I will post the results to all the newsgroups in which this
questionaire has appeared.  Please don't send requests, as this mail address
has been set up exclusively for processing the questionaires.

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

Date: 17 Apr 90 05:32:21 GMT
From: mentor.cc.purdue.edu![e-mail]  (Mark Gellis)
Subject: Re: Fermi Paradox


My own candidates for the solution to the Fermi Paradox are as follows:

1) We actually are alone.  (Or at least, we are the first technically
advanced civilization in the galaxy.)

2) There is no way around the lightspeed limit and intelligent civilizations
are fairly uncommon.

I played around, writing some sf stories, with realistic STL drives for
spacecraft, and the simple fact is that making them work is a real problem.
Unless you have practical FTL travel, interstellar trade and colonization
is going to be a very slow process, and not one that many beings, even very
long-lived ones, are likely to find interesting, if they are anything like
us (of course, they might not be).  Thus, the expanding sphere of solar
systems around a home system would be expanding at a very slow rate, perhaps
one light year per thousand years, perhaps even slower.

3) The aliens know about us and have set our solar system (and perhaps
even a small zone of systems nearby, like a 10 LY radius) off limits.
Enforcement would certainly be a problem, but I imagine it would only be
a minority of beings ("perverts") who would break the interdict, and
unless they were very smart and very careful, they would probably be
caught before they did too much damage.  If technological intelligences
are uncommon, we may be very precious to the galactic community, and the
level of protection may be very high, and the penalties for breaking the
interdict hideous beyond our imagination.  (UFO's may be either poachers,
licensed research craft, or galactic police.)

Enjoy.

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

Date: 15 Apr 90 19:35:36 GMT
From: van-bc!rsoft!mindlink![e-mail]  (Bruce Dunn)
Subject: Project HARP and Dr. Bull


     Dr. G. Bull was recently murdered in Europe.  It is believed that he was
killed as a result of his activities related to military weapons in the Middle
East.  In the 1960s, Dr. Bull was associated with project HARP (High Altitude
Research Project), run out of McGill University in Montreal, with U.S. Army
funding.  Project HARP involved the use of large guns to fire instrumented
ballistic projectiles and rockets to high altitudes.  The program seems to have
been terminated in approximately the mid 1960s.       Bull later became an arms
designer and arms broker, who had dealings with Iraq among other countries.
Recent news reports say that the British have intercepted a shipment of "pipe
segments" to Iraq, and feel that it represents pieces that could be assembled
into a very large gun for military purposes.  Bull seems to have been involved
in the design and/or acquisition of these potential gun components.  For
background information in interpreting the potential usefulness of such a large
gun, this message gives some basic information about project HARP from the open
literature, coupled with some personal comments.  Material in quotation marks
is from the cited papers.

Paper 1:  Bull, G.V. (1964) Development of Gun Launched Vertical Probes for
Upper Atmosphere Studies.  Canadian Aeronautics and Space Journal 10:236-247.

This paper was written to accompany a speech made by Bull in Toronto in May
1964.

In the Introduction to the paper:

"During the past several years, both theoretical and experimental
investigations have been undertaken to determine the applicability of guns to
scientific studies of the ionosphere.  Such possibilities have intrigued
ordnance workers for many years, but involve a complex mixing of advanced
gunnery techniques, scientific experiment considerations and economics.

"In late 1961, with material support from the US Army, McGill University
undertook the development of a 16 inch gun system.  In early 1962 this program
came under full support of the US Army through the Army Research Office and the
Ballistic Research Laboratories" In a section on sub-calibre ballistic
projectiles, Bull says:

"For example, in the case of a 16 inch naval gun which normally fires shells in
the 3,000 lb. class at velocities of 2,800 fps, velocities as high as 6,000 fps
can be obtained with shot weights of the order of 400 lbs., the sub-caliber
vehicle in this case having a ballistic coefficient considerably higher than
the normal shell.  By re-design of the gun (i.e. extending the chamber and
barrel) to optimize at this lighter shot weight, velocities approaching 7,000
fps are possible."

     A series of sub-calibre "Martlet 2" vehicles were built, which were
sub-calibre and rode the barrel in a fall-away sabot.  Canted fins on the
projectile maintained aerodynamic stability, and spun the projectile up so that
it was stable once leaving the atmosphere.  These were fired at elevations of
from 60 to 90 degrees from a 16 inch naval gun (on loan from the U.S.) which
was located in Barbados.  The gun was bored out to 16.5 inches and made into a
smooth-bore cannon.  Altitudes of approximately 500,000 to 600,000 feet (100
miles, 160 km) were projected for this arrangement, and early trial reported in
the reference cited went as high as 112 km.  Martlet vehicles carried
instruments made from discrete solid-state electronics - they were potted in a
mix of epoxy and sand (!) and the designers did not seem to have any real
trouble getting the electronic to survive the launch acceleration which peaked
at approximately 20,000 g.  Martlet vehicles also routinely carried a liquid
mixture of trimethyl-aluminum and triethyl-aluminum to be released at high
altitudes for ionosphere studies.  Another option was to carry sodium-thermite
mixes which when ignited would release sodium vapor (a type of experiment
similar to the Pegasus satellite barium releases).
     If projectiles of a similar weight were fired for range rather than height
then ranges of up to 150 to 200 miles were calculated, depending on the
ballistic coefficient.

Shots from the gun were routine and relatively inexpensive.  Bull states:

"Normally, loading of the gun can be accomplished in under one half hour,
allowing a firing rate of one an hour."

"Standard service propellant available as surplus (WM/.245) has been used, and
the gun geometry has not been modified.  Firing programs are planned for the
summer and fall of this year [1964] when the gun barrel will be extended and
lighter sabots used with propellant designed to match the light projectiles,
which should extend the Martlet 2A apogee to 200 km."

[if I remember correctly, the gun was fitted with a fiberglass muzzle extension
which was successful in improving the performance].

"The economics of the gun launched probe has been as predicted, with the
Martlet 2A airframes loaded with TMA/TEA and a flare in the nose cone varying
in price between $2500 and $3500, with gun launch costs (propellant and gun
wear) included."

After having discussed ballistic projectiles, Bull discusses gun-
launched rockets:

"Gun fired artillery rockets have been developed extensively since World War II
and normally must withstand barrel acceleration loads of the order of 30,000 g
along with the rotational loads superposed by shell spin.  The performance of
this type of rocket is only of marginal interest in the vertical probe
application where non-spinning (from a stress viewpoint) vehicles are flown at
acceleration levels of less than 10,000 g and relatively very large rocket
motors are desired with high mass fractions.
     In May of 1963, work was started on what was designated as the Martlet 3A
rocket assist vehicle as part of the HARP program.  The objective of this
activity was the development of a 16 inch gun launched probe which would carry
some 40 lbs. of payload to altitudes in the 500 km range."

     The Martlet 3A and later 3B rocket vehicles were sub-calibre and used
various solid propellants in various configurations. The main problem with gun
launched rockets is supporting the solid propellant during the launch
acceleration so that it does not collapse into the internal cavities molded
into the propellant grain, and a lot of development work was performed to
investigate the performance of various solid propellant grains.
          From their knowledge of the performance of the 16 inch gun system and
general information about the specific impulse and mass fraction of solid fuel
rockets, it was calculated that it would be fairly easy to put a payload into
orbit using the HARP gun and a multistage solid fuel rocket.  Orbital Launch
Vehicle Characteristics from Figure 31 in the Bull paper:

Total launch weight:     2000 lbs
Stage 1 weight:          1440 lbs
Stage 2 weight:           403 lbs
Stage 3 weight:           117 lbs
Payload:                   40 lbs

Muzzle velocity          4500 fps
Mass fraction             0.8
Specific impulse          300 sec (vacuum)

     The first and second stages were to be fired at relatively low altitude,
but clear of the atmosphere.  The third stage was to circularize the orbit, and
would be fired horizontally at orbital altitude.

    Such a vehicle was never built, although motors of the first stage size
were developed.  The HARP group was also involved in exploring the
possibilities of launching liquid fueled rockets from the gun.  These could be
thin-shelled as long as they had no gas spaces in them (you can accelerate a
balloon full of water at any g force you like, as long is it is fully supported
during the acceleration).



Paper 2: Eyre, F.W. (1966) The Development of Large Bore Gun Launched Rockets.
Canadian Aeronautics and Space Journal 12:143-149.

"The concept of a rocket launched from a gun is not new.  It will suffice to
affirm in this paper that the gun launched artillery rocket was in full
development during the Second World War and this investigation still continues.
Like so much work in allied fields, a great deal of what has been done and is
being done is classified and cannot here be repeated."

"The conventional solid propellant gun, firing meaningful projectiles,
currently appears able to develop a maximum muzzle velocity of some 6000 to
9000 fps.  Allowing an 80% recovery of muzzle kinetic energy as potential
energy, this corresponds to a ceiling for sounding work of some 800,000 to
1,000,000 ft. (say 160 to 200 statute miles). Significant improvements beyond
this level must come either from use of a different type of gun or from rocket
boost during vehicle flight, which is here considered."

"Figure 3 shows muzzle velocity vs. shot weight for the Barbados gun. [HARP]"

"Assumed conditions:  Max. pressure 60000 psi
                      Fixed charge, 1000 lbs M8M propellant
                      Web size optimized."

[some approximate data points from Figure 3 graph, and from Figure 4 showing
acceleration vs. shot weight]

Shot weight  Muzzle velocity  Max. acceleration
 500  lbs          7700 fps       13,000 g
1000  lbs          6400 fps        9,000 g
1500  lbs          5700 fps        6,500 g
2000  lbs          5200 fps        5,000 g

Eyre then goes into a long technical discussion related to how to support
propellants of various types in a solid fuel rocket during the gun
acceleration.  Perhaps the neatest concept is to simply fill all empty spaces
in the rocket with a fluid which then can support the propellant grain
hydrostatically during launch (sort of a rocket water-
bed).  The rocket is then accelerated using some form of pusher plate, which
seals the liquid in.  The plate drops away after launch, and the fluid is then
vented or drained before ignition.

With regard to practicality and performance, Eyre writes:

"It has transpired in design studies that although structural problems do arise
due to the acceleration loads, and additional problems are posed by the
necessity to use a folding stabilizer assembly, mass fractions almost as high
as conventional rockets can be achieved and the design problems are partially
alleviated by an all supersonic flight regime.
     Given this condition the advantage of the gun can be seen in that a
typical vehicle of mass fraction 0.8 would have an apogee of 176 miles used
conventionally, 257 miles at 1000 fps launch, 342 miles at 2000 fps, 435 miles
at 3000 fps, 529 miles at 4000 fps and so on."

     Eyre then discusses the fabrication of a full-scale, full bore (16 inch)
motor with a weight of 1450 lbs., designated the Martlet 4A and designed for
the Barbados gun.  At the time of writing of the paper, it does not appear as
if this had yet been test launched - I do not know how far the program was
carried before it was cancelled.

"Current work is directed towards development and application of a thin plastic
wear resistant coating [they were worried about excessive wear on the rocket
casing], and launching of 16 inch motors to investigate scale factor effects.
At the time of writing  [1966] full bore Aerojet General Corp. grains are
awaiting launch. ... At the present time a heavy test program is about to
commence with many agencies participating and for the most part full scale
hardware ready for launch."


     In summary, up until the time of writing of the later of the two quoted
papers in the mid 1960s, HARP under Dr. Bull appeared to have been highly
successful using a surplus 16 inch naval cannon in firing projectiles to high
altitudes and in firing solid fueled rockets.  If the gun had been aimed more
horizontally, great ranges would have been acheived.  It might be argued that
the "doomsday" gun which Iraq was said to be trying to assemble would not be
practical in an engineering sense.  However, Bull has been called the most
brilliant gun designer of this century.  If, as is probable, he was involved in
the Iraq gun, his track record suggests he would get it right.  His comment on
vehicle design for guns of different scales is interesting:

"Obviously since launch weight (ie payload) is increasing roughly as the cube
of the scale, while peak accelerations are decreasing linearly, the larger the
gun the simpler the vehicle engineering problem."      This comment applies to
vehicle design, but related arguments could be advanced for the problems of gun
design in relation to size.  If a large gun can be fixed in position (ie. by
putting it in a sloping tunnel) then gun length no longer has to be maintained
at 50 to 100 calibres or so.  If the gun were given external support, a long
thin-
walled gun with a modest internal pressure and modest projectile acceleration
could well give the same performance as a conventional short gun with thick
walls, high pressure, and high acceleration.  Such a long, low pressure gun
would also be easier to make than a conventional cannon of the same projectile
size and velocity.  The walls could be thin enough to be fabricated by
relatively conventional industry, and the gun could be assembled on the spot by
joining a number of sections.

Military implications:          If such a weapon were assembled, it would be
dandy for repeated delivery of tons of high-explosive or chemical to a fixed
target such as a distant city.  The downside would be that the gun would have a
fixed, known site and would be vulnerable to counterattack.  But then again,
missile silos can be hardened to survive all but very close hits by nuclear
weapons, and there is nothing inherently delicate in an underground cannon
which would be damaged by ground shock.  If properly protected in a tunnel, it
might take a direct hit by nuclear weapons to put it out of action.

Space implications:
     The Pegasus vehicle is solid fueled.  Remove its wings and give the B-52
back.  Develop a hydrostatic support system for the motors, and harden anything
delicate in the avionics.  Throw away the delicate satellite-type payload, and
substitute a g-insensitive bulk payload such rocket propellant, liquid oxygen,
water etc.  Launch from a long, wide-
bore, thin walled gun buried in a sloping tunnel.  With a launch velocity of
say 1500 m/sec, the payload to orbit will be a lot higher than Pegasus can
launch with the same rocket motors.  This may be a low-
cost approach to space station resupply.


Bruce Dunn    [e-mail]



--
Bruce Dunn   Vancouver, Canada    [e-mail]

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End of SPACE Digest V11 #274
*******************